United States Office of Air EPA 402-R-96-011 A
Environmental Protection and Radiation September 1994
Agency (6601J)
4vEPA Radiation Site Cleanup
Regulations:
Technical Support Document
For The Development Of
Radionuclide Cleanup Levels
For Soil
Review Draft
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Radiation Site Cleanup Regulations:
Technical Support Document
For The Development Of Radionuclide
Cleanup Levels For Soil
Review Draft
Prepared as a product of work sponsored by the
U.S. Environmental Protection Agency
under contract Number 68D20155
U.S. Environmental Protection Agency
Office of Radiation and Indoor Air
401 M Street, S.W.
Washington, DC 20460
September 26. 1994
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TABLE OF CONTENTS
Page
LIST OF TABLES vii
LIST OF FIGURES xiii
NOTICE xiii
ACKNOWLEDGEMENTS xiv
INTRODUCTION
Background
Technical Analysis Supporting the Rule
Scope of EPA's Cleanup Standards Regulatory Development Technical
Analysis, and Overview of This Report
1. MAGNITUDE OF THE CLEANUP PROBLEM
1.1 NUMBERS OF SITES
1.2 MAJOR CLEANUP PROGRAMS
1.2. 1 Superfund Program
1.2.2 Formerly Utilized Sites Remedial Action Program (FUSRAP)
1.2.3 Uranium Mill Tailings Remedial Action Program (UMTRAP)
1.2.4 Defense Environmental Restoration Program (DERP)
1.2.5 Site Decommissioning Management Plan (SDMP)
-1
-1
-2
-6
-1
-1
-4
-4
-5
-6
-7
-7
1.3 SITES GROUPED ACCORDING TO RESPONSIBLE AGENCIES/PROGRAMS ....
1.3. 1 Federal Facility Sites ...................................
1.3.2 NRC Licensees ........................................ 1-12
1.3.3 Non-Federal National Priorities List (NPL) Sites .............. 1-13
1.3.4 Sites Under State Control ................................ 1-14
1.4 FUNCTIONAL CATEGORIES ..................................... 1-14
1.5 VOLUME OF SOIL CONTAMINATED WITH RADIOACTIVITY .............. 1-14
2. SELECTION/DEVELOPMENT OF EXPOSURE SCENARIOS AND MODELS ........... 2-1
2. 1 EXPOSURE SCENARIOS AND MODELS FOR CALCULATING RADIATION
DOSE AND RISK TO INDIVIDUALS ................................ 2-2
2. 1. 1 Background ........................................... 2-2
2.1.2 EPA Superfund Exposure Scenarios ........................ 2-3
2. 1.3 Exposure Scenarios Used in the Proposed Soil Cleanup
Rule Analysis to Calculate Radiation Doses and Risks .......... 2-8
2.1.4 Basic Soil Exposure Pathway Models ...................... 2-13
2.1.5 Model Evaluation/Selection Criteria ........................ 2-13
2.1.6 Pathway Models/Codes Evaluated ........................ 2-14
2.1.7 Pathway Models Selected ................................ 2-14
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TABLE OF CONTENTS (Continued)
Page
2.2 CUMULATIVE POPULATION IMPACTS 2-44
2.2.1 Exposure Scenarios 2-44
2.2.2 Rationale for Excluding Selected Pathways from
the Population Impact Assessment 2-45
2.2.3 Future Land Use Scenarios 2-48
2.2.4 Time Periods of Concern 2-48
2.2.5 Model Description 2-49
3. ASSESSMENT OF MODELING PARAMETERS AND CAPABILITIES 3-1
3.1 GENERIC TEST SITE: INDIVIDUAL RISKS 3-2
3.1.1 Derivation of Generic Test Site Risk and Dose Factors 3-2
3.1.2 Modeling Parameters 3-30
3.1.3 Sensitivity Analysis 3-51
3.1.4 Uncertainty Analysis 3-75
3.2 Generic Test Site Population Impacts 3-75
3.2.1 Discussion of Radionuclides and
Time Periods of Interest 3-84
3.2.2 Discussion of Pathway Uncertainties and Sensitivities 3-93
3.2.3 Quantitative Sensitivity Analysis 3-103
4. DEVELOPMENT OF REFERENCE SITES 4-1
4.1 GATHERING THE DATA ON REPRESENTATIVE SITES 4-3
4.1.1 Sources of Data on DOE, DOD, andNRC Sites 4-4
4.1.2 Site Categorization Scheme 4-5
4.1.3 Aerial Surveys 4-9
4.2 SELECTION OF BASIS SITES 4-13
4.2.1 Site Selection Criteria 4-14
4.3 REFERENCE SITE WEIGHTING FACTORS 4-18
4.4 CONSTRUCTION OF REFERENCE SITES 4-21
4.4.1 Parameters Used in Dose and Risk Assessments 4-21
4.4.2 Characterizing the Radionuclide Distributions 4-25
4.4.3 Description of Reference Sites 4-35
5. ANALYSIS OF REFERENCE SITES 5-1
5.1 SOIL CLEANUP VOLUMES FOR REFERENCE SITES 5-1
5.1.1 Step 2: Derivation of Risk Factors 5-2
5.1.2 Step 3: Soil Cleanup Volumes 5-3
5.2 RADIOLOGICAL IMPACTS AVERTED DUE TO SOIL CLEANUP 5-9
5.2.1 Step 1: Derivation of Population Health Effect Factors 5-11
5.2.2 Step 2: Calculation of Radionuclide Inventories
of Remediated Soil 5-11
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TABLE OF CONTENTS (Continued)
Page
5.3 POTENTIAL RADIOGENIC CANCERS CAUSED BY CLEANUP 5-16
5.3.1 Radiological Impacts on Workers During Cleanup 5-16
5.3.2 Off-Site Impacts During Remediation 5-18
5.3.3 Impacts Due to Radiation Exposures During Waste Transport . . . 5-26
5.3.4 Impacts Associated With Exposures at a Disposal Facility 5-26
5.4 RESULTS AND CONCLUSIONS 5-27
5.4.1 Benefits vs. Volumes of Soil Remediated 5-27
5.4.2 Summary of Fundamental Assumptions 5-30
5.5 SUPPLEMENTARY CALCULATIONS-DOSE-BASED CLEANUP LEVELS 5-31
6. DISCUSSION OF SENSITIVITIES AND UNCERTAINTIES IN SOIL CLEANUP
VOLUMES AND IMPACTS AVERTED 6-1
6.1 DISCUSSION OF SENSITIVITIES AND UNCERTAINTIES IN THE SOIL
CLEANUP VOLUMES AT REFERENCE SITES 6-1
6.1.1 Overall Sensitivity of the Results 6-2
6.1.2 Discussion of Uncertainties in Soil Cleanup Volumes 6-6
6.1.3 Summary of Uncertainties in Cleanup Volumes 6-61
6.2 EVALUATION OF SENSITIVITIES AND UNCERTAINTIES INESTIMATES
FATAL CANCERS AVERTED DUE TO SITE CLEANUP 6-61
6.2.1 Overview of Results 6-63
6.2.2 Discussion of Uncertainties 6-67
7. IMPLEMENTATION CONSIDERATIONS 7-1
7.1 STRATEGIES FOR DERIVING SOIL CLEANUP CONCENTRATIONS 7-1
7.1.1 Basis for Form of the Standard 7-1
7.1.2 Proposed Implementation Guidance on Soil Cleanup Concentrations .... 7-2
7.2 TECHNICAL FEASIBILITY ISSUES ASSOCIATED WITH IMPLEMENTATION . . 7-14
7.2.1 Lower Limit of Detection 7-15
7.2.2 Background Soil Concentration 7-39
7.2.3 Demonstrating Compliance With EPA's Proposed
Drinking Water Standards 7-43
7.3 EPA IMPLEMENTATION GUIDANCE DOCUMENTS 7-49
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Appendix A - Footnotes for Table 1-1 A-l
Appendix B - Parameter Values Used in Pathway/Risk Modeling B-l
Appendix C - Modified RAGS/HHEM Equations C-l
Appendix D - Description of Terminology Used by the Census Bureau D-l
Appendix E - Methodology for Deriving Population Impacts E-l
Appendix F - Comparison of Health Risks Arising from the Radiological and
Chemical Toxicity of Uranium F-l
Appendix G - PRESTO-CPG Input Parameters G-l
Appendix H - Results of RESRAD Parameter Sensitiity Analyses H-
Appendix I - RAGS/HHEM Monte Carlo Uncertainty Analysis I-
Appendix J - Analysis of Aerial Radiological Surveys J-
Appendix K - Risk Based Results of Reference Site Analyses K-
Appendix M- Dose Based Results of Reference Site Analyses L-
Appendix N- Population Model Results of Reference Site Analyses N-
Appendix O- Background Radiation and Lower Limits of Detection O-l
Review Draft - 9/26/94 VI Do Not Cite or Quote
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LIST OF TABLES
Table Page
1-1 Inventory by Agency of Sites That Are Known
to be Contaminated with Radioactivity 1-2
1-2 Inventory of Sites That are Known
to be Contaminated with Radioactivity 1-3
1-3 Estimated Radioactively-Contaminated Soil Volume 1-16
2-1 EPA Superfund Land Use Classifications and Standard Default Exposure Factors 2-4
2-2 Exposure Pathways Assumed for Radiation Dose and Risk Calculations 2-9
2-3 Examples of Code Usage 2-15
2-4 Pathway Model Evaluation 2-17
2-5 Comparison of Pathway Models 2-20
2-6 Principal and Associated Radionuclides 2-27
2-7 Radionuclide Concentration in Groundwater (pCi/L) Based on
Distribution Coefficient (Kd) 2-36
2-8 Relative Pathway Contribution to Risk 2-46
2-9 A List of ETF2 /ETFj for Eight Radionuclides 2-47
2-10 Population Density by County Within a Circle of 80 Km
Radius for DOE/DOD Sites 2-49
2-11 Pathways Included in the Suburban and Rural
Scenarios Used to Derive Cumulative Population Dose 2-62
3-1 RESRAD (Ver. 5.19) Risk Factors and Dose Factors for the Generic Site,
Assuming Suburban Exposure 3-4
3-2 RESRAD (Ver. 5.19) Risk Factors and Dose Factors for the Generic Site,
Assuming Rural Residential Exposure 3-6
3-3 RESRAD (Ver. 5.19) Risk Factors and Dose Factors for the Generic Site,
Assuming Commercial/Industrial Exposure 3-8
3-4 PRESTO-CPG Risk Factors and Dose Factors for the Generic Site,
Assuming Suburban Exposure 3-10
3-5 PRESTO-CPG Risk Factors and Dose Factors for the Generic Site,
Assuming Rural Residential Exposure 3-12
3-6 PRESTO-CPG Risk Factors and Dose Factors for the Generic Site,
Assuming Commercial/Industrial Exposure 3-14
3-7 RAGS/HHEM Part B Risk Factors and Dose Factors for the Generic Site,
Assuming Suburban Exposure 3-16
3-8 RAGS/HHEM Part B Risk Factors and Dose Factors for the Generic Site,
Assuming Rural Residential Exposure 3-18
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LIST OF TABLES (Continued)
Table Page
3-9 RAGS/HHEM Part B Risk Factors and Dose Factors for the Generic Site,
Assuming Commercial/Industrial Exposure 3-20
3-10 Comparison of Model Results for the Generic Test Site,
Assuming Rural Residential Exposure 3-26
3-11 Generic Test Site - Base Case Analysis Values 3-32
3-12 Comparison of Generic and Reference Site Characteristics 3-41
3-13 Distribution Coefficients Used in Generic Test Site Exposure and Risk Modeling 3-43
3-14 Modified Parameters and Input Values Used in Sensitivity Analyses 3-52
3-15 RESRAD Parameter Sensitivity Analysis: Contaminated Zone Area 3-55
3-16 RESRAD Parameter Sensitivity Analysis: Contaminated Zone Thickness .... 3-58
3-17 RESRAD Parameter Sensitivity Analysis: Infiltration Rate 3-60
3-18 RESRAD Parameter Sensitivity Analysis: Distribution Coefficient 3-63
3-19 RESRAD Parameter Sensitivity Analysis: Unsaturated Zone Thickness 3-65
3-20 Distribution of Radionuclides by Dominant Pathway 3-68
3-21 Generic Population Impacts (Case 1) - 100 Years 3-79
3-22 Generic Population Impacts (Case 1) - 1,000 Years 3-80
3-23 Generic Population Impacts (Case 1) - 10,000 Years 3-81
3-24 Interim Population Model Pathways 3-82
3-25 Agricultural Productivity 3-100
3-26 Generic Population Impacts (Case 2) - 100 Years 3-104
3-27 Generic Population Impacts (Case 2) - 1,000 Years 3-105
3-28 Generic Population Impacts (Case 2) - 10,000 Years 3-106
3-29 Generic Population Impacts (Case 3) - 100 Years 3-109
3-30 Generic Population Impacts (Case 3) - 1,000 Years 3-110
3-31 Generic Population Impacts (Case 3) - 10,000 Years 3-111
4-1 Site Categories Characterized by the Survey 4-6
4-2 Criteria for the Selection/Construction of Reference Sites
Required to Support Soil Cleanup Rule 4-15
4-3 Reference Sites 4-16
4-4 Range of Parameter Values for Site Types A, B, and C 4-22
4-5 Selected Parameter Values for Site Types A, B, and C 4-24
4-6 Characteristics of Contamination at Reference Sites 4-26
4-7 Characteristics of Contaminated and Unsaturated Zones
at the Reference Sites 4-28
4-8 Saturated Zone Characteristics at the Reference Sites 4-29
4-9 Areas of Cs-137 Contamination at the Hanford Site 4-38
4-10 Areas of Uranium Contamination Adjacent to FEMP 4-44
4-11 Areas of Cs-137 Contamination at INEL 4-55
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LIST OF TABLES (Continued)
Table Page
4-12 Volumes of Soil Contaminated by U-238 at Reference Site IV 4-61
4-13 Distribution of Cs-137 in Contaminated Soil 4-64
4-14 Contamination of Surface Soils at Oak Ridge 4-69
4-15 Volumes of Soil Contaminated with Pu-239 at NTS 4-72
4-16 Areas of Cs-137 Contamination at NTS 4-73
4-17 Statistical Analysis of Radiological Assay of Soil Samples 4-83
4-18 Relative Isotopic Masses of Natural and Depleted Uranium 4-90
4-19 Uranium Contamination at Reference Site XX 4-97
4-20 Radioactive Contamination at 10 Vicinity Properties
on the Maywood Site 4-105
5-1 Soil Volumes Requiring Remediation - Residential (excluding Rn) 5-5
5-2 Soil Volumes Requiring Remediation - Commercial/Industrial (excluding Rn) . . 5-6
5-3 Soil Volumes Requiring Remediation - Residential (including Rn) 5-7
5-4 Soil Volumes Requiring Remediation - Commercial/Industrial (including Rn) . . 5-8
5-5 Fatal Cancers Averted - Reasonable Occupancy (excluding Rn) 5-12
5-6 Fatal Cancers Averted - Commercial/Industrial (excluding Rn) 5-13
5-7 Fatal Cancers Averted - Reasonable Occupancy (including Rn) 5-14
5-8 Fatal Cancers Averted - Commercial/Industrial (including Rn) 5-15
5-9 Fatal Cancers Among Remediation Workers (excluding Rn) 5-19
5-10 Maximum Lifetime Risk of Fatal Radiological Cancer From Site Cleanup .... 5-22
5-11 Total Fatal Cancers Within 80 km Radius of a Generic Site Over a
1-Year Period Following Site Cleanup 5-22
5-12 x/Q and Population Distributions 5-23
6-1 Total Soil Volume Requiring Remediation 6-4
6-2a Residential Scenario Maximum Health Impact Per Unit Concentration
for a 1,000-Yr Period 6-7
6-2b Residential Scenario Dose Rate Per Unit Concentration for a 1,000-Yr Period . . 6-9
6-3 Comparison of Risk Factors 6-13
6-4 Summary of Potential Fatal Cancers Averted Due to Cleanup
of Contaminated Soil 6-65
6-5 Population Density 0-80 km and County Population Density
for DOE/DOD Sites 6-69
6-6 Population Health Impacts (for 1,000 Years) (including Rn) 6-70
6-7 Cleanup Volume (excluding Rn) 6-74
6-8 Activities Removed (including Rn) 6-75
7-1 Example Look-Up Table of Radionuclide Soil Cleanup Concentrations 7-4
7-2 Example Table of Adjustment Factors 7-10
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LIST OF TABLES (Continued)
Table Page
7-3 Comparison of Generic and Reference Site Soil Concentrations 7-12
7-4 Comparison of Rural Residential Soil Concentrations With
Minimum Detectable Concentrations and Background 7-17
7-5 Comparison of Surburban Soil Concentrations With
MDC's and Background 7-20
7-6 Comparison of Commercial/Industrial Soil Concentrations With
Minimum Detectable Concentrations and Background 7-23
7-7 Comparison of Rural Residential Soil Concentrations With
Field Minimum Detectable Concentrations and Background 7-27
7-8 Comparison of Suburban Soil Concentrations With
Field Minimum Detectable Concentrations and Background 7-30
7-9 Comparison of Commercial/Industrial Soil Concentrations With
Field Minimum Detectable Concentrations and Background 7-33
7-10 Evaluation of Generic Soil Concentrations That Could Exceed
EPA's Proposed Drinking Water Standards 7-45
Review Draft - 9/26/94 X Do Not Cite or Quote
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LIST OF FIGURES
Figure Page
I Flow of Work 1-8
2-2 Radionuclide Concentration in Soil Over Time 2-32
3-1 Radionuclide Distribution by Dominant Pathway - RESRAD Ver. 5.19 3-22
3-2 Radionuclide Distribution by Dominant Pathway - PRESTO-CPG 3-23
3-3 Radionuclide Distribution by Dominant Pathway - RAGS/HHEM Part B 3-24
3-4 Generic Test Site Characteristics 3-40
3-5 Cs-137+D RESRAD Parameter Sensitivity Analysis 3-69
3-6 Pu-239 RESRAD Parameter Sensitivity Analysis 3-71
3-7 U-238+D RESRAD Parameter Sensitivity Analysis 3-72
3-8 H-3 RESRAD Parameter Sensitivity Analysis 3-74
3-9 Ra-226+D RESRAD Parameter Sensitivity Analysis 3-76
3-10 Th-230 RESRAD Parameter Sensitivity Analysis 3-77
3-11 U-238 Decay Series 3-85
3-12 Th-232 Decay Series 3-92
3-13 Generic Population Impacts - 1,000 Year Case 3-114
3-14 Generic Population Impacts - Suburban Scenario 3-114
4-1 Reference Site I - Volume of Contaminated Soil 4-30
4-2 Reference Site I - Complementary Cumulative Volume
of Contaminated Soil 4-31
4-3 Reference Site XII - Distribution of Contaminated Soil 4-33
4-4 Reference Site I - Distribution of Contaminated Soil 4-40
4-5 Reference Site II-1 - Distribution of Contaminated Soil 4-46
4-6 Reference Site II-2 - Distribution of Contaminated Soil 4-47
4-7 Reference Site II-3 - Distribution of Contaminated Soil 4-48
4-8 Reference Site II-4 - Distribution of Contaminated Soil 4-49
4-9 Reference Site II-5 - Distribution of Contaminated Soil 4-50
4-10 Reference Site II-6 - Distribution of Contaminated Soil 4-51
4-11 Reference Site II-7 - Distribution of Contaminated Soil 4-52
4-12 Reference Site III - Distribution of Contaminated Soil 4-57
4-13 Reference Site IV - Distribution of Contaminated Soil 4-60
4-14 Reference Site V - Distribution of Contaminated Soil 4-65
4-15 Reference Site VI - Distribution of Contaminated Soil 4-70
4-16 Reference Site VII - Distribution of Contaminated Soil 4-74
4-17 Reference Site IX - Distribution of Contaminated Soil 4-78
4-18 Reference Site X - Distribution of Contaminated Soil 4-82
4-19 Reference Site XII - Distribution of Contaminated Soil 4-86
4-20 Reference Site XIII - Distribution of Contaminated Soil 4-91
Review Draft - 9/26/94 XI Do Not Cite or Quote
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LIST OF FIGURES (Continued)
Figure Page
4-21 Reference Site XVI - Distribution of Contaminated Soil 4-93
4-22 Reference Site XVIII - Distribution of Contaminated Soil 4-96
4-23 Reference Site XX - Distribution of Contaminated Soil 4-98
4-24 Reference Site XXI - Distribution of Contaminated Soil 4-101
4-25 Reference Site XXII - Distribution of Contaminated Soil 4-106
5-1 Reference Site II - Volume of Soil Remediated and Fatal Cancers
Averted, 1,000 Years, Excluding Radon 5-28
5-2 Reference Site II - Volume of Soil Remediated and Fatal Cancers
Averted, 1,000 Years, Including Radon 5-29
6-1 Soil Cleanup Volumes (U.S. Total) 6-5
6-2 Site I - Dose Rate vs. Time 6-16
6-3 Site I - Total Dose Rate vs. Time 6-19
6-4 Site II - Ra-226+D Dose Rate vs. Time 6-21
6-5 Site IIB-7 - Total Dose Rate vs. Time 6-23
6-6 Site IIB-7 - U-238 Dose Rate vs. Time 6-24
6-7 Site IIB-7 - U-234, U-235, U-238 and All Progeny 6-28
6-8 Site IV - Total Dose Rate vs. Time 6-34
6-9 Site IV - U-234, U-235, U-238 and All Progeny 6-35
6-10 Site V - Dose Rate vs. Time 6-37
6-11 Site VI - Contribution to Total Dose Rate vs. Time 6-39
6-12 Site VI - Total Dose Rate vs. Time 6-40
6-13 Site VII - Contribution to Total Dose Rate vs. Time 6-41
6-14 Site VII - Cs-137 Dose Rate vs. Time 6-42
6-15 Site VII - Pu-239 Dose Rate vs. Time 6-43
6-16 Site VII - Am-241 Dose Rate vs. Time 6-44
6-17 Site XVI A, B, & C - Contribution to Total Dose Rate vs. Time 6-51
6-18 Site XVI A, B, & C - Total Dose Rate vs. Time 6-52
6-19 Site XVI A, B, & C - Co-60 Dose Rate vs. Time 6-53
6-20 Site XVI A, B, & C - Cs-137 Dose Rate vs. Time 6-54
6-21 Site XVIII A, B, & C - Contribution to Total Dose Rate vs. Time 6-56
6-22 Site XVIII A, B, & C - Total Dose Rate vs. Time 6-57
6-23 Site XVIII A, B, & C - Cs-137 Dose Rate vs. Time 6-58
6-24 Site XVIII A, B, & C - Sr-90 Dose Rate vs. Time 6-59
6-25 Curies Removed for Critical Isotopes vs. Risk-Based Cleanup Goal 6-66
Review Draft - 9/26/94 Xll Do Not Cite or Quote
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Errata to the Draft TSD
This file presents an errata to the draft Technical Support Document (TSD), Technical Support
Document for the Development of Radionuclide Cleanup Levels for Soil, EPA 402-R-96-011 A:
Main Report. Included are corrections for typographical errors and other types of errors or
modifications made to the text of the draft TSD by ORIA. Many of these errors and corrections
were originally listed in an initial errata sheet and subsequent mark-up submitted by ORIA to the
EPA Science Advisory Board (SAB) during and shortly after SAB's review of the draft TSD.
Errata (Page numbers refer to the September 1994 draft TSD.)
Page 1-6, line 22 should read: "EPA is conducting its technical analysis in three separate...."
Page 1-8: Asterisks should be on boxes 11 and 12, not on 7 and 8.
Page 1-5, top of page: Delete third bullet from the top of the page, and the indentation.
Page 2-8, second paragraph, last line should read: "...considered moderately conservative, perhaps
typical of a fairly average suburbanite, rather than applicable to the RME individual of the rural
residential scenario."
Page 2-58, paragraph beginning middle of page, line 2:
"[Inv(O) x e-DF3(t-T)]" should read "[Inv(O) x e-DF3xt]";
lines 5 and 6 should read: "..., and the factor e"XT describes the decay of the radionuclide over the
source-to-aquifer transport time, T; and that the...."
Pages 2-59 to 2-61, Section 2.2.5, the term "RSC" refers to average radionuclide soil
concentration, rather than the target level.
Page 3-1, point number 1, line 5, should read"...comparisons also assist in the selection of a model
for use in estimating the risks to individuals..."
Page 3-85: Half-life of U-238 is 4.5xl09 years.
Page 3-88, line 11: Here and throughout the text, the word "concentration" refers to picocuries
of contaminant per gram of soil, per liter of water, etc.
Page 3-89, line 3, should read: "...100 year time period..."
Page 4-3, line 12, sentence should end with a period.
Page 4-6 and 4-7. Footnote for Table 4-1 appears on page 4-8 and should appear on pages 4-6
and 4-7 also. In addition, there should be only a single check mark for functional category 1 for
mills, category 6 for "NRC licensed/other government", category 7 for "radiochemical /analytical"
and "sealed source manufacturing."
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Page 4-9, third paragraph, and elsewhere, "g-ray" should read "gamma ray."
Page 4-25, footnote. "CCDF" means "complementary cumulative density function."
Pages 4-33, 4-40, etc.: Delete box containing "Total Contaminated Volume = ... m**3."
Page 4-41, see attached table of distribution parameters for Reference Site II.
Page 4-45, line 9 should read: "...being the total number of samples analyzed for that nuclide.
The average background..."
Page 4-59, line 19 should read: "...cumulative contaminated volume is linear in the logarithm of
the level of the of U-23 8..."
Page 4-69, first paragraph, line 10 refers to a free-release limit for cesium. This sentence should
read: "(This is slightly larger than the area contaminated by Cs-137 in excess of the present NRC
guidance and technical precedent, as discussed for Reference Site V, which is also 15 pCi/g.)"
Page 4-75, see attached table of distribution parameters for Reference Site IX.
Page 4-94, see attached table of distribution parameters for Reference Sites XVIII.
Pages 6-7 and 6-8, Table caption should read: "Reference Site Residential Scenario Risk Factors
(Cancer Incidence Risk per pCi/g) over 1,000 Years."
Page 6-13, Table caption should read: "Reference Site Residential Scenario Risk Factors (Cancer
Incidence Risk per pCi/g) over 1,000 Years, Assuming Only One Radionuclide Present at the Site.
(See footnote, Page 6-6)."
Page 6-15, Paragraph 2 should begin: "In addition to the uncertainty in the estimate..."
Page 6-88, line 4 and below: Replace "AF2" with "AF4."
Enclosure 3 - Groundwater Report January, 1996
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Enclosure 5: Revised and Supplementary Data Tables
There are two parts to the revised and supplementary data tables. Part 1 contains a revised
version of Table 4-6 and a replacement table for Tables 6-2a and 6-2b of the draft TSD. Part 2
contains supplementary data tables for Appendix M of the draft TSD.
Part 1. Revised Draft TSD Data Tables
The first table of Part 1 is a revised version of Table 4-6 of the draft TSD, which reflects the
change in the area of Reference Site X. As described in Section 4.4.3 of the draft TSD,
Reference Site X was originally constructed to represent a single WMU at Paducah. In order to
represent the entire site, the area was increased in later analyses.
The second table of Part 1 replaces Tables 6-2a and 6-2b of the draft TSD. Risk and dose factors
for the commercial/industrial occupancy scenario were added. In addition, the table has been
updated to reflect the currently-used dose and risk factors. The factors for Reference Site X were
changed due to the revised characterization of this site, as discussed above. In other cases, some
clerical errors were corrected and other modeling refinements were incorporated. Except for
Reference Site X, none of the changes had any significant impact on the analyses.
Revised/Supplementary Data Tables 1 January, 1996
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Revised Draft TSD Table 4-6. Characteristics of Contamination at Reference Sites3
Reference
Site
I
II-1/II-6
II-7
III
IV
V
VI
VII
IX
X
Contaminated Area
(m2)
2.26E+07
3.96E+06
1.11E+07
1.81E+07
5.90E+05
1.12E+07
6.70E+06
3.70E+08
4.00E+06
2.36E+05
Chemical
Elements
Cs
Ac
Pa
Pb
Ra
Th
U
Ac
Pa
Pb
Ra
Th
U
Cs
Ac
Pa
Pb
Ra
Th
U
Cs
Cs
Ac
Pa
Pb
Ra
Th
U
Pu
Am
Cs
Pu
Am
Tc
Ac
Pa
Pb
Ra
Th
U
Kb
J^d
280
2400
2700
550
9100
5800
1,600
2400
2700
550
9100
5800
1,600
1,900
794
330
150
165
1500
330
500C
10,000d
2400
2700
550
9100
5800
1,600
550
1,900
280
10,000e
112,000e
0.1
450
550
270
500
3200
35
Contaminated Zone
Thickness (m)
0.05
0.50
0.05
0.05
0.108
0.05
0.05
0.06
0.05
0.305
Revised/Supplementary Data Tables
January, 1996
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Reference
Site
XII
XIII
XVI
XVIII
XX
XXI
XXII
Contaminated Area
(m2)
1.90E+04
4.19E+04
7.00E+03
3.30E+03
2.00E+04
1.38E+04
3.70E+05
Chemical
Elements
Pu
Am
Ac
Pa
Pb
Ra
Th
U
Co
Cs
Cs
Sr
Ac
Pa
Pb
Ra
Th
U
Ra
Th
Ac
Pa
Pb
Ra
Th
U
Kdb
550
1,900
104
182
469
502
21,909
89
447
894
894
21
104
182
469
502
21,909
89
502
21,909
450
550
270
500
3200
35
Contaminated Zone
Thickness (m)
0.9
.08
0.15
0.15
1.0/0.36f
2.50
2.0
a Selected values discussed in the text, except where otherwise noted (ANL 93b, DOE 93a).
b RESRAD 5.0 default values based on soil type, DOE 93a, p. 32-38, unless otherwise noted.
c RAE 91, p. 3-63. Original reference is Lo 87.
d ORNL 88.
e Han 80, p. 152.
f See text
Revised/Supplementary Data Tables
January, 1996
-------
Replacement Table for Tables 6a and 6b of the Draft TSD:
Normalized Maximum Risk and Dose Factors for RME Individuals During First 1,000 Years
Ref.
Site
I
II- 1/6
II-7
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
Nuclide
Cs-137
Pb-210
Ra-226
Th-230
Ra-228
Th-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
Normalized Lifetime Risk of Cancer
(Risk per pCi/g)
Residential
Radon
2.66E-05
9.26E-06
3.12E-04
2.63E-05
1.66E-04
1.82E-04
2.75E-04
4.52E-07
7.51E-06
2.03E-06
1.27E-07
4.60E-06
8.32E-07
2.66E-05
2.74E-07
6.52E-06
1.41E-06
2.66E-05
2.66E-05
1.27E-07
4.60E-06
8.32E-07
1.96E-07
2.88E-07
3.03E-05
1.63E-07
2.48E-07
3.43E-05
4.08E-05
2.73E-05
6.61E-07
7.87E-07
1.17E-06
5.84E-06
2.02E-07
1.17E-06
5.84E-06
2.02E-07
No Radon
2.66E-05
9.26E-06
1.92E-04
2.06E-05
1.66E-04
1.82E-04
2.75E-04
4.52E-07
7.51E-06
2.03E-06
1.27E-07
4.60E-06
8.32E-07
2.66E-05
2.74E-07
6.52E-06
1.41E-06
2.66E-05
2.66E-05
1.27E-07
4.60E-06
8.32E-07
1.96E-07
2.88E-07
3.03E-05
1.63E-07
2.48E-07
3.43E-05
4.08E-05
2.73E-05
6.61E-07
7.87E-07
1.17E-06
5.84E-06
2.02E-07
1.17E-06
5.84E-06
2.02E-07
Commercial
Radon
7.80E-06
7.83E-08
9.25E-05
7.77E-06
4.91E-05
5.62E-05
8.20E-05
7.85E-08
2.26E-06
5.37E-07
2.63E-08
1.41E-06
2.38E-07
7.80E-06
5.64E-08
1.99E-06
3.94E-07
7.80E-06
7.80E-06
2.62E-08
1.41E-06
2.38E-07
4.75E-08
7.64E-08
8.87E-06
3.95E-08
6.63E-08
1.24E-05
1.56E-05
1.05E-05
1.16E-07
1.52E-07
3.30E-07
1.79E-06
4.14E-08
3.30E-07
1.79E-06
4.14E-08
No Radon
7.80E-06
7.83E-08
5.54E-05
6.00E-06
4.91E-05
5.62E-05
8.20E-05
7.85E-08
2.26E-06
5.37E-07
2.63E-08
1.41E-06
2.38E-07
7.80E-06
5.64E-08
1.99E-06
3.94E-07
7.80E-06
7.80E-06
2.62E-08
1.41E-06
2.38E-07
4.75E-08
7.64E-08
8.87E-06
3.95E-08
6.63E-08
1.24E-05
1.56E-05
1.05E-05
1.16E-07
1.52E-07
3.30E-07
1.79E-06
4.14E-08
3.30E-07
1.79E-06
4.14E-08
Normalizec
(mrem/y
Residential
Radon
1.23E+00
1.59E+00
2.49E+01
1.92E+00
8.31E+00
8.57E+00
1.43E+01
7.49E-02
5.32E-01
1.35E-01
2.24E-02
3.13E-01
5.06E-02
1.23E+00
4.80E-02
4.52E-01
9.23E-02
1.23E+00
1.23E+00
2.24E-02
3.13E-01
5.06E-02
1.12E-01
1.31E-01
1.40E+00
9.29E-02
1.10E-01
5.13E-01
3.09E+00
3.20E+00
3.77E-01
4.06E-01
7.35E-02
4.01E-01
3.54E-02
7.35E-02
4.01E-01
3.54E-02
No Radon
1.23E+00
1.59E+00
8.98E+00
1.12E+00
8.31E+00
8.57E+00
1.43E+01
7.49E-02
5.32E-01
1.35E-01
2.24E-02
3.13E-01
5.06E-02
1.23E+00
4.80E-02
4.52E-01
9.23E-02
1.23E+00
1.23E+00
2.24E-02
3.13E-01
5.06E-02
1.12E-01
1.31E-01
1.40E+00
9.29E-02
1.10E-01
5.13E-01
3.09E+00
3.20E+00
3.77E-01
4.06E-01
7.35E-02
4.01E-01
3.54E-02
7.35E-02
4.01E-01
3.54E-02
I Dose Rate
per pCi/g)
Commercial
Radon
4.41E-01
1.58E-02
8.80E+00
6.54E-01
2.81E+00
3.18E+00
4.92E+00
1.93E-02
1.89E-01
4.19E-02
6.53E-03
1.15E-01
1.71E-02
4.41E-01
1.39E-02
1.64E-01
3.06E-02
4.41E-01
4.41E-01
6.52E-03
1.15E-01
1.71E-02
3.24E-02
4.01E-02
5.01E-01
2.70E-02
3.40E-02
2.23E-01
1.42E+00
1.47E+00
7.93E-02
8.99E-02
2.45E-02
1.46E-01
1.02E-02
2.45E-02
1.46E-01
1.02E-02
No Radon
4.41E-01
1.58E-02
2.96E+00
3.64E-01
2.81E+00
3.18E+00
4.92E+00
1.93E-02
1.89E-01
4.19E-02
6.53E-03
1.15E-01
1.71E-02
4.41E-01
1.39E-02
1.64E-01
3.06E-02
4.41E-01
4.41E-01
6.52E-03
1.15E-01
1.71E-02
3.24E-02
4.01E-02
5.01E-01
2.70E-02
3.40E-02
2.23E-01
1.42E+00
1.47E+00
7.93E-02
8.99E-02
2.45E-02
1.46E-01
1.02E-02
2.45E-02
1.46E-01
1.02E-02
Revised/Supplementary Data Tables
January, 1996
-------
Replacement Table for Tables 6a and 6b of the Draft TSD (Continued)
Ref.
Site
XIIIC
XVIA
XVIB
XVIC
XVIIIA
XVIIIB
XVIIIC
XXA
XXB
xxc
XXIA
XXIB
XXIC
XXII
Nuclide
U-238
U-235
U-234
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Ra-228
Th-228
Th-232
Ra-228
Th-228
Th-232
Ra-228
Th-228
Th-232
Ra-226
Th-232
Th-228
U-234
U-235
U-238
Pb-210
Ra-228
Normalized Lifetime Risk of Cancer
(Risk per pCi/g)
Residential
Radon
1.17E-06
5.84E-06
2.02E-07
2.03E-04
4.83E-05
2.03E-04
4.83E-05
2.03E-04
4.83E-05
4.73E-05
4.39E-06
4.73E-05
4.39E-06
4.73E-05
4.39E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
1.14E-03
3.63E-07
1.74E-04
2.37E-05
2.70E-05
3.52E-05
1.50E-05
1.06E-04
No Radon
1.17E-06
5.84E-06
2.02E-07
2.03E-04
4.83E-05
2.03E-04
4.83E-05
2.03E-04
4.83E-05
4.73E-05
4.39E-06
4.73E-05
4.39E-06
4.73E-05
4.39E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
2.03E-04
3.62E-07
1.67E-04
2.36E-05
2.70E-05
3.52E-05
1.50E-05
1.06E-04
Commercial
Radon
3.30E-07
1.79E-06
4.14E-08
6.27E-05
1.44E-05
6.27E-05
1.44E-05
6.27E-05
1.44E-05
1.44E-05
3.79E-09
1.44E-05
3.79E-09
1.44E-05
3.79E-09
7.71E-08
2.26E-06
5.36E-07
7.71E-08
2.26E-06
5.36E-07
7.71E-08
2.26E-06
5.36E-07
2.70E-05
5.17E-05
9.31E-08
2.70E-05
5.17E-05
9.31E-08
2.70E-05
5.17E-05
9.31E-08
3.44E-04
9.50E-08
5.37E-05
9.28E-06
1.03E-05
1.38E-05
7.82E-08
2.70E-05
No Radon
3.30E-07
1.79E-06
4.14E-08
6.27E-05
1.44E-05
6.27E-05
1.44E-05
6.27E-05
1.44E-05
1.44E-05
3.79E-09
1.44E-05
3.79E-09
1.44E-05
3.79E-09
7.71E-08
2.26E-06
5.36E-07
7.71E-08
2.26E-06
5.36E-07
7.71E-08
2.26E-06
5.36E-07
2.70E-05
5.17E-05
9.31E-08
2.70E-05
5.17E-05
9.31E-08
2.70E-05
5.17E-05
9.31E-08
5.58E-05
9.50E-08
5.17E-05
9.21E-06
1.03E-05
1.38E-05
7.82E-08
2.70E-05
Normalizec
(mrem/y
Residential
Radon
7.35E-02
4.01E-01
3.54E-02
9.32E+00
2.23E+00
9.32E+00
2.23E+00
9.32E+00
2.23E+00
2.21E+00
2.60E-01
2.21E+00
2.60E-01
2.21E+00
2.60E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
1.35E+02
7.28E-01
7.63E+00
2.78E+00
2.90E+00
2.67E+00
2.58E+00
6.13E+00
No Radon
7.35E-02
4.01E-01
3.54E-02
9.32E+00
2.23E+00
9.32E+00
2.23E+00
9.32E+00
2.23E+00
2.21E+00
2.60E-01
2.21E+00
2.60E-01
2.21E+00
2.60E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
9.78E+00
7.28E-01
7.04E+00
2.76E+00
2.90E+00
2.67E+00
2.58E+00
6.15E+00
I Dose Rate
per pCi/g)
Commercial
Radon
2.45E-02
1.46E-01
1.02E-02
3.46E+00
8.11E-01
3.46E+00
8.11E-01
3.46E+00
8.11E-01
8.11E-01
4.27E-04
8.11E-01
4.27E-04
8.11E-01
4.27E-04
1.89E-02
1.89E-01
4.16E-02
1.89E-02
1.89E-01
4.16E-02
1.89E-02
1.89E-01
4.16E-02
1.58E+00
2.61E+00
2.29E-01
1.58E+00
2.61E+00
2.29E-01
1.58E+00
2.61E+00
2.29E-01
4.90E+01
2.33E-01
2.83E+00
1.30E+00
1.33E+00
1.25E+00
1.58E-02
1.58E+00
No Radon
2.45E-02
1.46E-01
1.02E-02
3.46E+00
8.11E-01
3.46E+00
8.11E-01
3.46E+00
8.11E-01
8.11E-01
4.27E-04
8.11E-01
4.27E-04
8.11E-01
4.27E-04
1.89E-02
1.89E-01
4.16E-02
1.89E-02
1.89E-01
4.16E-02
1.89E-02
1.89E-01
4.16E-02
1.58E+00
2.61E+00
2.29E-01
1.58E+00
2.61E+00
2.29E-01
1.58E+00
2.61E+00
2.29E-01
2.99E+00
2.33E-01
2.61E+00
1.29E+00
1.33E+00
1.25E+00
1.58E-02
1.58E+00
Revised/Supplementary Data Tables
January, 1996
-------
Part 2. Supplementary Tables of Potential Impacts Averted
This part supplements the tables provided in Appendix M of the draft TSD. The Appendix M
tables present estimates of cleanup volumes and potential radiological impacts averted (e.g.,
individual doses, population doses, worker doses, total cancers and fatal cancers) at reference
sites as a result of site remediation to alternative dose-based cleanup criteria. They also provide
estimates of radioactivity that would be removed in achieving alternative dose-based cleanup
goals. These tables present estimates for cases with and without consideration of indoor radon.
For the "with radon" case, the quantity of soil requiring remediation is slightly greater than that
of the "without radon" case. The number of potential health impacts averted following cleanup is
slightly greater for the "with radon" case. This part supplements the estimates presented in the
tables provided in Appendix M of the draft TSD by assessing those cases in which the indoor
radon pathway is excluded from the assessment of doses to the RME individual, but is included
in the calculation of cumulative collective impacts—cancer morbidity and mortality among
future populations occupying the site after cleanup.
Four sets of tables are provided in this part, as follows:
Table 1. Cleanup Volumes: Residential Occupancy
Table 2. Cleanup Volumes: Commercial Occupancy
Table 3. Total Cancers Averted if site is released for Residential Occupancy
Table 4. Total Cancers Averted if site is released for Commercial Occupancy
Table 5. Fatal Cancers Averted if site is released for Residential Occupancy
Table 6. Fatal Cancers Averted if site is released for Commercial Occupancy
Table 7. Maximum Residual Concentration: Residential Occupancy
Table 8. Maximum Residual Concentration: Commercial Occupancy
Tables 1 and 2 present the cleanup volumes as functions of alternative dose-based cleanup goals.
As the cleanup goals become more restrictive, the volume of soil requiring remediation to
achieve the cleanup goals increases. Tables 3 to 6 present the time integrated cumulative
population impacts averted by cleanup. Tables 7 and 8 present the maximum residual
radionuclide concentration at the sites following remediation.
As is shown in the above list of titles, there are four pairs of tables. In each pair, one table is
based on cleanup assuming that the site will be released for unrestricted use, while the second
table is based on the assumption that the site will be released with restrictions on future use. The
first case is modeled by the residential agrarian scenario (called "residential" for short), while the
second is represented by the commercial/industrial scenario ("commercial" for short). Since the
radiation exposure of a person residing on a radioactively contaminated site would higher than
that of an individual who only works on such a site, the dose factors (annual dose per unit
Revised/Supplementary Data Tables 6 January, 1996
-------
specific activity in the soil) based on residential occupancy assumptions are higher than those for
commercial occupancy. Consequently, more soil must be remediated and more radioactivity
removed for a given site to be released for residential use. As a result, the cumulative collective
impacts averted are greater in such a case. (The calculation of impacts on future populations
assumes that any occupancy restrictions imposed at the time a site is released will be eventually
forgotten or ignored, and all sites will revert to residential use.)
The results are provided for three future time periods of interest: 100, 1,000 and 10,000 years.
As the time periods of interest increase, the impacts averted increase because the impacts are
integrated over longer time periods. The cleanup volumes can also vary with time, since the dose
factor is the maximum dose rate during a given period. The dose rates from some nuclides may
peak at some time in the future due to buildup of daughter products or travel time to an
underground water supply. In all cases studied in the present analysis, the peak dose rate
occurred during the first 1,000 years, and in most cases during the first 100 years. Consequently,
the maximum residual concentrations, and hence the cleanup volumes, are little affected by the
alternative time periods of interest.
Lastly, all the analyses were based on the assumption that, for the three reference sites indicated
in the tables, cleanup is assumed not to begin until 30 years from now in order to allow some
radioactive decay of the shorter-lived radionuclides. This leads to a reduction of the
concentrations at the time of cleanup, resulting in a reduction in the volume of soil requiring
remediation as well as of the impacts averted.
Revised/Supplementary Data Tables 7 January, 1996
-------
Table 1
07-21-95 5:22p--30-y delay for Reference Sites I, III and V.
CLEANUP VOLUMES (m**3)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
.10
100
2 .35E+6
1.74E+6
8.28E+5
2 .34E+5
1.22E+7
5.03E+5
5.90E+7
3 .66E+5
7.77E+5
1.34E+4
2 .15E+3
2 .15E+3
2 .15E+3
1.21E+3
1.21E+3
1.21E+3
5.92E+2
5.92E+2
5.92E+2
4 .94E+5
4 .94E+5
4 .94E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .29E+6
1.05E+8
3 .16E+4
7.87E+6
1.13E+8
1
1, 000
2 .35E+6
1.76E+6
8.28E+5
2 .34E+5
1.22E+7
5.03E+5
5.90E+7
3 .66E+5
8.00E+5
1.34E+4
2 .15E+3
2 .15E+3
2 .15E+3
1.21E+3
1.21E+3
1.21E+3
5.92E+2
5.92E+2
5.92E+2
4 .94E+5
4 .94E+5
4 .94E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .29E+6
1.05E+8
3 .16E+4
7.87E+6
1.13E+8
10, 000
2 .35E+6
1.76E+6
8.28E+5
2 .34E+5
1.22E+7
5.03E+5
5.90E+7
3 .66E+5
8.00E+5
1.34E+4
2 .15E+3
2 .15E+3
2 .15E+3
1.21E+3
1.21E+3
1.21E+3
5.92E+2
5.92E+2
5.92E+2
4 .94E+5
4 .94E+5
4 .94E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .29E+6
1.05E+8
3 .16E+4
7.87E+6
1.13E+8
.50
100
1.03E+6
1.30E+6
7.45E+5
1.19E+5
9.03E+6
3 .90E+5
4 .02E+7
1.73E+5
6 .54E+5
7.43E+3
8.80E+2
8.80E+2
8.80E+2
1.10E+3
1.10E+3
1.10E+3
5.88E+2
5.88E+2
5.88E+2
1.14E+5
1.14E+5
1.14E+5
3 .42E+4
3 .42E+4
3 .42E+4
1.84E+6
7.49E+7
1.49E+4
2 .53E+6
7.74E+7
1, 000
1.03E+6
1.31E+6
7.45E+5
1.19E+5
9.03E+6
3 .90E+5
4 .02E+7
1.73E+5
7.92E+5
7.43E+3
8.80E+2
8.80E+2
8.80E+2
1.10E+3
1.10E+3
1.10E+3
5.88E+2
5.88E+2
5.88E+2
1.14E+5
1.14E+5
1.14E+5
3 .42E+4
3 .42E+4
3 .42E+4
1.84E+6
7.50E+7
1.49E+4
2 .53E+6
7.76E+7
10, 000
1.03E+6
1.31E+6
7.45E+5
1.19E+5
9.03E+6
3 .90E+5
4 .02E+7
1.73E+5
7.92E+5
7.43E+3
8.80E+2
8.80E+2
8.80E+2
1.10E+3
1.10E+3
1.10E+3
5.88E+2
5.88E+2
5.88E+2
1.14E+5
1.14E+5
1.14E+5
3 .42E+4
3 .42E+4
3 .42E+4
1.84E+6
7.50E+7
1.49E+4
2 .53E+6
7.76E+7
1. 00
100
7.18E+5
1.11E+6
6 .53E+5
8.91E+4
7.66E+6
3 .42E+5
2 .63E+7
1.12E+5
5.47E+5
4 .67E+3
3 .72E+2
3 .72E+2
3 .72E+2
1.06E+3
1.06E+3
1.06E+3
5.86E+2
5.86E+2
5.86E+2
5.98E+4
5.98E+4
5.98E+4
3 .39E+4
3 .39E+4
3 .39E+4
1.64E+6
5.64E+7
7.84E+3
1.75E+6
5.81E+7
1, 000
7.18E+5
1.12E+6
6 .53E+5
8.91E+4
7.66E+6
3 .42E+5
2 .63E+7
1.12E+5
7.81E+5
4 .67E+3
3 .72E+2
3 .72E+2
3 .72E+2
1.06E+3
1.06E+3
1.06E+3
5.86E+2
5.86E+2
5.86E+2
5.98E+4
5.98E+4
5.98E+4
3 .39E+4
3 .39E+4
3 .39E+4
1.64E+6
5.66E+7
7.84E+3
1.75E+6
5.84E+7
10, 000
7.18E+5
1.12E+6
6 .53E+5
8.91E+4
7.66E+6
3 .42E+5
2 .63E+7
1.12E+5
7.81E+5
4 .67E+3
3 .72E+2
3 .72E+2
3 .72E+2
1.06E+3
1.06E+3
1.06E+3
5.86E+2
5.86E+2
5.86E+2
5.98E+4
5.98E+4
5.98E+4
3 .39E+4
3 .39E+4
3 .39E+4
1.64E+6
5.66E+7
7.84E+3
1.75E+6
5.84E+7
3 .00
100
4 .08E+5
9.44E+5
3 .86E+5
5.63E+4
5.51E+6
2 .66E+5
1.34E+7
5.07E+4
3 .80E+5
2 .24E+3
5.32E+1
5.32E+1
5.32E+1
9.78E+2
9.78E+2
9.78E+2
5.82E+2
5.82E+2
5.82E+2
2 .13E+4
2 .13E+4
2 .13E+4
3 .28E+4
3 .28E+4
3 .28E+4
1.33E+6
3 .64E+7
2 .69E+3
1.18E+6
3 .76E+7
1, 000
4 .08E+5
9.50E+5
3 .86E+5
5.63E+4
5.51E+6
2 .66E+5
1.34E+7
5.07E+4
7.40E+5
2 .24E+3
5.32E+1
5.32E+1
5.32E+1
9.78E+2
9.78E+2
9.78E+2
5.82E+2
5.82E+2
5.82E+2
2 .13E+4
2 .13E+4
2 .13E+4
3 .28E+4
3 .28E+4
3 .28E+4
1.34E+6
3 .69E+7
2 .69E+3
1.18E+6
3 .81E+7
10, 000
4 .08E+5
9.50E+5
3 .86E+5
5.63E+4
5.51E+6
2 .66E+5
1.34E+7
5.07E+4
7.40E+5
2 .24E+3
5.32E+1
5.32E+1
5.32E+1
9.78E+2
9.78E+2
9.78E+2
5.82E+2
5.82E+2
5.82E+2
2 .13E+4
2 .13E+4
2 .13E+4
3 .28E+4
3 .28E+4
3 .28E+4
1.34E+6
3 .69E+7
2 .69E+3
1.18E+6
3 .81E+7
5.00 ||
100
2 .87E+5
9.19E+5
2 .28E+5
4 .54E+4
4 .50E+6
2 .31E+5
9.81E+6
3 .26E+4
2 .97E+5
1.71E+3
.OOE+0
.OOE+0
.OOE+0
9.34E+2
9.34E+2
9.34E+2
5.80E+2
5.80E+2
5.80E+2
1.18E+4
1.18E+4
1.18E+4
3 .18E+4
3 .18E+4
3 .18E+4
1.19E+6
2 .96E+7
1.71E+3
1.02E+6
3 .06E+7
1, 000
2 .87E+5
9.35E+5
2 .28E+5
4 .54E+4
4 .50E+6
2 .31E+5
9.81E+6
3 .26E+4
6 .97E+5
1.71E+3
.OOE+0
.OOE+0
.OOE+0
9.34E+2
9.34E+2
9.34E+2
5.80E+2
5.80E+2
5.80E+2
1.18E+4
1.18E+4
1.18E+4
3 .18E+4
3 .18E+4
3 .18E+4
1.21E+6
3 .02E+7
1.71E+3
1.02E+6
3 .12E+7
1
10,000
1
1
2 .87E+5
9.35E+5
2 .28E+5
4 .54E+4
4 .50E+6
2 .31E+5
9.81E+6
3 .26E+4
6 .97E+5
1.71E+3
.OOE+0
.OOE+0
.OOE+0
9.34E+2
9.34E+2
9.34E+2
5.80E+2
5.80E+2
5.80E+2
1.18E+4
1.18E+4
1.18E+4
3 .18E+4
3 .18E+4
3 .18E+4
1.21E+6
3 .02E+7
1.71E+3
1.02E+6
3 .12E+7
-------
Table 1 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
CLEANUP VOLUMES (m**3)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
10. 00
100
1.73E+5
8.63E+5
1.43E+5
3 .42E+4
3 .44E+6
1.85E+5
6 .63E+6
1.74E+4
2 .14E+5
1.65E+3
.OOE+0
.OOE+0
.OOE+0
8.70E+2
8.70E+2
8.70E+2
5.55E+2
5.55E+2
5.55E+2
3 .17E+3
3 .17E+3
3 .17E+3
2 .85E+4
2 .85E+4
2 .85E+4
1.02E+6
2 .27E+7
1.65E+3
8.15E+5
2 .36E+7
1
1, 000
1.73E+5
9.00E+5
1.43E+5
3 .42E+4
3 .44E+6
1.85E+5
6 .63E+6
1.74E+4
5.94E+5
1.65E+3
.OOE+0
.OOE+0
.OOE+0
8.70E+2
8.70E+2
8.70E+2
5.55E+2
5.55E+2
5.55E+2
3 .17E+3
3 .17E+3
3 .17E+3
2 .85E+4
2 .85E+4
2 .85E+4
1.06E+6
2 .35E+7
1.65E+3
8.15E+5
2 .43E+7
10, 000
1.73E+5
9.00E+5
1.43E+5
3 .42E+4
3 .44E+6
1.85E+5
6 .63E+6
1.74E+4
5.94E+5
1.65E+3
.OOE+0
.OOE+0
.OOE+0
8.70E+2
8.70E+2
8.70E+2
5.55E+2
5.55E+2
5.55E+2
3 .17E+3
3 .17E+3
3 .17E+3
2 .85E+4
2 .85E+4
2 .85E+4
1.06E+6
2 .35E+7
1.65E+3
8.15E+5
2 .43E+7
15.00
100
1.28E+5
8.19E+5
1.07E+5
3 .03E+4
2 .87E+6
1.59E+5
5.18E+6
1.06E+4
1.77E+5
1.61E+3
.OOE+0
.OOE+0
.OOE+0
7.93E+2
7.93E+2
7.93E+2
5.36E+2
5.36E+2
5.36E+2
5.48E+2
5.48E+2
5.48E+2
2 .64E+4
2 .64E+4
2 .64E+4
9.06E+5
1.92E+7
1.61E+3
7.22E+5
1.99E+7
1, 000
1.28E+5
8.67E+5
1.07E+5
3 .03E+4
2 .87E+6
1.59E+5
5.18E+6
1.06E+4
5.09E+5
1.61E+3
.OOE+0
.OOE+0
.OOE+0
7.93E+2
7.93E+2
7.93E+2
5.36E+2
5.36E+2
5.36E+2
5.48E+2
5.48E+2
5.48E+2
2 .64E+4
2 .64E+4
2 .64E+4
9.89E+5
2 .02E+7
1.61E+3
7.22E+5
2 .09E+7
10, 000
1.28E+5
8.67E+5
1.07E+5
3 .03E+4
2 .87E+6
1.59E+5
5.18E+6
1.06E+4
5.09E+5
1.61E+3
.OOE+0
.OOE+0
.OOE+0
7.93E+2
7.93E+2
7.93E+2
5.36E+2
5.36E+2
5.36E+2
5.48E+2
5.48E+2
5.48E+2
2 .64E+4
2 .64E+4
2 .64E+4
9.89E+5
2 .02E+7
1.61E+3
7.22E+5
2 .09E+7
25. 00
100
8.77E+4
7.94E+5
5.96E+4
2 .54E+4
2 .14E+6
1.35E+5
2 .84E+6
6 .22E+3
1.40E+5
1.57E+3
.OOE+0
.OOE+0
.OOE+0
6 .92E+2
6 .92E+2
6 .92E+2
5.13E+2
5.13E+2
5.13E+2
1.10E+2
1.10E+2
1.10E+2
2 .38E+4
2 .38E+4
2 .38E+4
8.13E+5
1.48E+7
1.57E+3
6 .44E+5
1.54E+7
1, 000
8.77E+4
8.12E+5
5.96E+4
2 .54E+4
2 .14E+6
1.35E+5
2 .84E+6
6 .22E+3
3 .88E+5
1.57E+3
.OOE+0
.OOE+0
.OOE+0
6 .92E+2
6 .92E+2
6 .92E+2
5.13E+2
5.13E+2
5.13E+2
1.10E+2
1.10E+2
1.10E+2
2 .38E+4
2 .38E+4
2 .38E+4
8.40E+5
1.53E+7
1.57E+3
6 .44E+5
1.59E+7
10, 000
8.77E+4
8.12E+5
5.96E+4
2 .54E+4
2 .14E+6
1.35E+5
2 .84E+6
6 .22E+3
3 .88E+5
1.57E+3
.OOE+0
.OOE+0
.OOE+0
6 .92E+2
6 .92E+2
6 .92E+2
5.13E+2
5.13E+2
5.13E+2
1.10E+2
1.10E+2
1.10E+2
2 .38E+4
2 .38E+4
2 .38E+4
8.40E+5
1.53E+7
1.57E+3
6 .44E+5
1.59E+7
75.00
100
3 .83E+4
7.63E+5
5.86E+3
1.49E+4
8.07E+5
8.82E+4
4 .88E+5
1.34E+3
7.71E+4
1.28E+3
.OOE+0
.OOE+0
.OOE+0
5.65E+2
5.65E+2
5.65E+2
4 .OOE+2
4 .OOE+2
4 .OOE+2
4 .19E+1
4 .19E+1
4 .19E+1
1.82E+4
1.82E+4
1.82E+4
5.48E+5
7.99E+6
1.28E+3
4 .97E+5
8.49E+6
1, 000
3 .83E+4
7.73E+5
5.86E+3
1.49E+4
8.07E+5
8.82E+4
4 .88E+5
1.34E+3
1.51E+5
1.28E+3
.OOE+0
.OOE+0
.OOE+0
5.65E+2
5.65E+2
5.65E+2
4 .OOE+2
4 .OOE+2
4 .OOE+2
4 .19E+1
4 .19E+1
4 .19E+1
1.82E+4
1.82E+4
1.82E+4
5.85E+5
8.33E+6
1.28E+3
4 .97E+5
8.83E+6
10, 000
3 .83E+4
7.73E+5
5.86E+3
1.49E+4
8.07E+5
8.82E+4
4 .88E+5
1.34E+3
1.51E+5
1.28E+3
.OOE+0
.OOE+0
.OOE+0
5.65E+2
5.65E+2
5.65E+2
4 .OOE+2
4 .OOE+2
4 .OOE + 2
4 .19E+1
4 .19E + 1
4 .19E+1
1.82E+4
1.82E+4
1.82E+4
5.85E+5
8.33E+6
1.28E+3
4 .97E+5
8.83E+6
100.00 ||
100
2 .63E+4
7.51E+5
3 .98E+3
1.22E+4
7.01E+5
7.62E+4
3 .26E+5
7.55E+2
6 .26E + 4
1.17E+3
.OOE+0
.OOE+0
.OOE+0
5.34E+2
5.34E+2
5.34E+2
3 .65E+2
3 .65E+2
3 .65E+2
3 .25E+1
3 .25E+1
3 .25E+1
1.57E+4
1.57E+4
1.57E+4
5.30E+5
7.28E+6
1.17E+3
4 .35E+5
7.71E+6
1, 000
2 .63E+4
7.60E+5
3 .98E+3
1.22E+4
7.01E+5
7.62E+4
3 .26E+5
7.55E+2
1.16E+5
1.17E+3
.OOE+0
.OOE+0
.OOE+0
5.34E+2
5.34E+2
5.34E+2
3 .65E+2
3 .65E+2
3 .65E+2
3 .25E+1
3 .25E+1
3 .25E+1
1.57E+4
1.57E+4
1.57E+4
5.42E+5
7.43E+6
1.17E+3
4 .35E + 5
7.87E+6
1
10,000
1
1
2 .63E+4
7.60E+5
3 .98E+3
1.22E+4
7.01E+5
7.62E+4
3 .26E+5
7.55E+2
1.16E+5
1.17E+3
.OOE+0
.OOE+0
.OOE+0
5.34E+2
5.34E+2
5.34E+2
3 .65E+2
3 .65E+2
3 .65E+2
3 .25E+1
3 .25E+1
3 .25E+1
1.57E+4
1.57E+4
1.57E+4
5.42E+5
7.43E+6
1.17E+3
4 .35E+5
7.87E+6
-------
Table 2
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
CLEANUP VOLUMES (m**3)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
.10
100
1.39E+6
1.44E+6
7.90E+5
1.46E+5
1.02E+7
4 .31E+5
5.07E+7
2 .10E+5
7.94E+5
7.73E+3
1.33E+3
1.33E+3
1.33E+3
1.15E+3
1.15E+3
1.15E+3
5.90E+2
5.90E+2
5.90E+2
1.45E+5
1.45E+5
1.45E+5
3 .43E+4
3 .43E+4
3 .43E+4
1.96E+6
8.90E+7
1.90E+4
2 .96E+6
9.20E+7
1
1, 000
1.39E+6
1.45E+6
7.90E+5
1.46E+5
1.02E+7
4 .31E+5
5.07E+7
2 .10E+5
7.98E+5
7.73E+3
1.33E+3
1.33E+3
1.33E+3
1.15E+3
1.15E+3
1.15E+3
5.90E+2
5.90E+2
5.90E+2
1.45E+5
1.45E+5
1.45E+5
3 .43E+4
3 .43E+4
3 .43E+4
1.96E+6
8.90E+7
1.90E+4
2 .96E+6
9.20E+7
10, 000
1.39E+6
1.45E+6
7.90E+5
1.46E+5
1.02E+7
4 .31E+5
5.07E+7
2 .10E+5
7.98E+5
7.73E+3
1.33E+3
1.33E+3
1.33E+3
1.15E+3
1.15E+3
1.15E+3
5.90E+2
5.90E+2
5.90E+2
1.45E+5
1.45E+5
1.45E+5
3 .43E+4
3 .43E+4
3 .43E+4
1.96E+6
8.90E+7
1.90E+4
2 .96E+6
9.20E+7
.50
100
6 .05E+5
9.85E+5
5.89E+5
7.42E+4
7.01E+6
3 .19E+5
1.89E+7
7.84E+4
7.59E+5
2 .63E+3
3 .30E+2
3 .30E+2
3 .30E+2
1.03E+3
1.03E+3
1.03E+3
5.84E+2
5.84E+2
5.84E+2
3 .21E+4
3 .21E+4
3 .21E+4
3 .36E+4
3 .36E+4
3 .36E+4
1.50E+6
4 .67E+7
5.44E+3
1.36E+6
4 .81E+7
1, 000
6 .05E+5
9.87E+5
5.89E+5
7.42E+4
7.01E+6
3 .19E+5
1.89E+7
7.84E+4
7.79E+5
2 .63E+3
3 .30E+2
3 .30E+2
3 .30E+2
1.03E+3
1.03E+3
1.03E+3
5.84E+2
5.84E+2
5.84E+2
3 .21E+4
3 .21E+4
3 .21E+4
3 .36E+4
3 .36E+4
3 .36E+4
1.51E+6
4 .68E+7
5.44E+3
1.36E+6
4 .81E+7
10, 000
6 .05E+5
9.87E+5
5.89E+5
7.42E+4
7.01E+6
3 .19E+5
1.89E+7
7.84E+4
7.79E+5
2 .63E+3
3 .30E+2
3 .30E+2
3 .30E+2
1.03E+3
1.03E+3
1.03E+3
5.84E+2
5.84E+2
5.84E+2
3 .21E+4
3 .21E+4
3 .21E+4
3 .36E+4
3 .36E+4
3 .36E+4
1.51E+6
4 .68E+7
5.44E+3
1.36E+6
4 .81E+7
1. 00
100
4 .23E + 5
9.40E+5
4 .08E+5
5.55E+4
5.65E+6
2 .71E+5
1.24E+7
4 .62E+4
7.18E+5
1.71E+3
1.34E+2
1.34E+2
1.34E+2
9.87E+2
9.87E+2
9.87E+2
5.81E+2
5.81E+2
5.81E+2
1.58E+4
1.58E+4
1.58E+4
3 .28E+4
3 .28E+4
3 .28E+4
1.31E+6
3 .59E+7
2 .85E+3
1.10E+6
3 .70E+7
1, 000
4 .23E+5
9.48E+5
4 .08E+5
5.55E+4
5.65E+6
2 .71E+5
1.24E+7
4 .62E+4
7.56E+5
1.71E+3
1.34E+2
1.34E+2
1.34E+2
9.87E+2
9.87E+2
9.87E+2
5.81E+2
5.81E+2
5.81E+2
1.58E+4
1.58E+4
1.58E+4
3 .28E+4
3 .28E+4
3 .28E+4
1.32E+6
3 .60E+7
2 .85E+3
1.10E+6
3 .71E+7
10, 000
4 .23E+5
9.48E+5
4 .08E+5
5.55E+4
5.65E+6
2 .71E+5
1.24E+7
4 .62E+4
7.57E+5
1.71E+3
1.34E+2
1.34E+2
1.34E+2
9.87E+2
9.87E+2
9.87E+2
5.81E+2
5.81E+2
5.81E+2
1.58E+4
1.58E+4
1.58E+4
3 .28E + 4
3 .28E+4
3 .28E+4
1.32E+6
3 .60E+7
2 .85E+3
1.10E+6
3 .71E+7
3 .00
100
1.97E+5
8.65E+5
1.58E+5
3 .51E+4
3 .69E+6
1.97E+5
6 .61E+6
1.70E+4
5.54E+5
1.62E+3
.OOE+0
.OOE+0
.OOE+0
8.93E+2
8.93E+2
8.93E+2
5.59E+2
5.59E+2
5.59E+2
1.69E+3
1.69E+3
1.69E+3
2 .88E+4
2 .88E+4
2 .88E+4
1.03E+6
2 .38E+7
1.62E+3
8.05E+5
2 .46E+7
1, 000
1.97E+5
9.03E+5
1.58E+5
3 .51E+4
3 .69E+6
1.97E+5
6 .61E+6
1.70E+4
6 .63E+5
1.62E+3
.OOE+0
.OOE+0
.OOE+0
8.93E+2
8.93E+2
8.93E+2
5.59E+2
5.59E+2
5.59E+2
1.69E+3
1.69E+3
1.69E+3
2 .88E+4
2 .88E+4
2 .88E+4
1.09E+6
2 .43E+7
1.62E+3
8.05E+5
2 .51E+7
10, 000
1.97E+5
9.03E+5
1.58E+5
3 .51E+4
3 .69E+6
1.97E+5
6 .61E+6
1.70E+4
6 .65E+5
1.62E+3
.OOE+0
.OOE+0
.OOE+0
8.93E+2
8.93E+2
8.93E+2
5.59E+2
5.59E+2
5.59E+2
1.69E+3
1.69E+3
1.69E+3
2 .88E+4
2 .88E+4
2 .88E+4
1.09E+6
2 .43E+7
1.62E+3
8.05E+5
2 .51E+7
5.00 ||
100
1.35E+5
8.11E+5
1.14E+5
3 .OOE+4
2 .97E+6
1.63E+5
4 .67E+6
8.75E+3
4 .42E+5
1.57E+3
.OOE+0
.OOE+0
.OOE+0
8.14E+2
8.14E+2
8.14E+2
5.36E+2
5.36E+2
5.36E+2
1.72E+2
1.72E+2
1.72E+2
2 .62E+4
2 .62E+4
2 .62E+4
8.95E+5
1.91E+7
1.57E+3
7.15E+5
1.98E+7
1, 000
1.35E+5
8.62E+5
1.14E+5
3 .OOE+4
2 .97E+6
1.63E+5
4 .67E+6
8.75E+3
5.78E+5
1.57E+3
.OOE+0
.OOE+0
.OOE+0
8.14E+2
8.14E+2
8.14E+2
5.36E+2
5.36E+2
5.36E+2
1.72E+2
1.72E+2
1.72E+2
2 .62E+4
2 .62E+4
2 .62E+4
l.OOE+6
2 .OOE+7
1.57E+3
7.15E+5
2 .08E+7
1
10,000
1
1
1.35E+5
8.62E+5
1.14E+5
3 .OOE+4
2 .97E+6
1.63E+5
4 .67E+6
8.75E+3
5.81E+5
1.57E+3
.OOE+0
.OOE+0
.OOE+0
8.14E+2
8.14E+2
8.14E+2
5.36E+2
5.36E+2
5.36E+2
1.72E+2
1.72E+2
1.72E+2
2 .62E+4
2 .62E+4
2 .62E+4
l.OOE+6
2 .OOE+7
1.57E+3
7.15E+5
2 .08E+7
-------
Table 2 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
CLEANUP VOLUMES (m**3)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
10. 00
100
8.09E+4
7.89E+5
5.04E+4
2 .34E+4
1.99E+6
1.30E+5
1.92E+6
4 .19E+3
2 .81E+5
1.49E+3
.OOE+0
.OOE+0
.OOE+0
6 .77E+2
6 .77E+2
6 .77E+2
5.04E+2
5.04E+2
5.04E+2
7.46E+1
7.46E+1
7.46E+1
2 .27E+4
2 .27E+4
2 .27E+4
7.89E+5
1.36E+7
1.49E+3
6 .17E+5
1.42E+7
1
1, 000
8.09E+4
7.97E+5
5.04E+4
2 .34E+4
1.99E+6
1.30E+5
1.92E+6
4 .19E+3
4 .20E+5
1.49E+3
.OOE+0
.OOE+0
.OOE+0
6 .77E+2
6 .77E+2
6 .77E+2
5.04E+2
5.04E+2
5.04E+2
7.46E+1
7.46E+1
7.46E+1
2 .27E+4
2 .27E+4
2 .27E+4
8.22E+5
1.40E+7
1.49E+3
6 .17E+5
1.46E+7
10, 000
8.09E+4
7.97E+5
5.04E+4
2 .34E+4
1.99E+6
1.30E+5
1.92E+6
4 .19E+3
4 .24E+5
1.49E+3
.OOE+0
.OOE+0
.OOE+0
6 .77E+2
6 .77E+2
6 .77E+2
5.04E+2
5.04E+2
5.04E+2
7.46E+1
7.46E+1
7.46E+1
2 .27E+4
2 .27E+4
2 .27E+4
8.22E+5
1.40E+7
1.49E+3
6 .17E+5
1.46E+7
15.00
100
6 .14E+4
7.78E+5
2 .23E+4
1.95E+4
1.42E+6
1.13E+5
9.44E+5
2 .11E+3
2 .02E+5
1.31E+3
.OOE+0
.OOE+0
.OOE+0
6 .27E+2
6 .27E+2
6 .27E+2
4 .62E+2
4 .62E+2
4 .62E+2
5.22E+1
5.22E+1
5.22E+1
2 .06E+4
2 .06E+4
2 .06E+4
6 .68E+5
1.06E+7
1.31E+3
5.62E+5
1.12E+7
1, 000
6 .14E+4
7.88E+5
2 .23E+4
1.95E+4
1.42E+6
1.13E+5
9.44E+5
2 .11E+3
3 .21E+5
1.31E+3
.OOE+0
.OOE+0
.OOE+0
6 .27E+2
6 .27E+2
6 .27E+2
4 .62E+2
4 .62E+2
4 .62E+2
5.22E+1
5.22E+1
5.22E+1
2 .06E+4
2 .06E+4
2 .06E+4
7.43E+5
1.13E+7
1.31E+3
5.62E+5
1.19E+7
10, 000
6 .14E+4
7.88E+5
2 .23E+4
1.95E+4
1.42E+6
1.13E+5
9.44E+5
2 .11E+3
3 .24E+5
1.31E+3
.OOE+0
.OOE+0
.OOE+0
6 .27E+2
6 .27E+2
6 .27E+2
4 .62E+2
4 .62E+2
4 .62E+2
5.22E+1
5.22E+1
5.22E+1
2 .06E+4
2 .06E+4
2 .06E+4
7.43E+5
1.13E+7
1.31E+3
5.62E+5
1.19E+7
25. 00
100
4 .21E+4
7.60E+5
6 .33E+3
1.46E+4
8.33E+5
9.07E+4
4 .27E+5
1.08E+3
1.35E+5
1.11E+3
.OOE+0
.OOE+0
.OOE+0
5.76E+2
5.76E+2
5.76E+2
3 .99E+2
3 .99E+2
3 .99E+2
3 .33E+1
3 .33E+1
3 .33E+1
1.80E+4
1.80E+4
1.80E+4
5.45E+5
8.05E+6
1.11E+3
4 .95E+5
8.55E+6
1, 000
4 .21E+4
7.70E+5
6 .33E+3
1.46E+4
8.33E+5
9.07E+4
4 .27E+5
1.08E+3
2 .03E+5
1.11E+3
.OOE+0
.OOE+0
.OOE+0
5.76E+2
5.76E+2
5.76E+2
3 .99E+2
3 .99E+2
3 .99E+2
3 .33E+1
3 .33E+1
3 .33E+1
1.80E+4
1.80E+4
1.80E+4
5.88E+5
8.43E+6
1.11E+3
4 .95E+5
8.93E+6
10, 000
4 .21E+4
7.70E+5
6 .33E+3
1.46E+4
8.33E+5
9.07E+4
4 .27E+5
1.08E+3
2 .06E+5
1.11E+3
.OOE+0
.OOE+0
.OOE+0
5.76E+2
5.76E+2
5.76E+2
3 .99E+2
3 .99E+2
3 .99E+2
3 .33E+1
3 .33E+1
3 .33E+1
1.80E+4
1.80E+4
1.80E+4
5.88E+5
8.44E+6
1.11E+3
4 .95E+5
8.93E+6
75.00
100
l.OOE+4
6 .94E+5
.OOE+0
4 .09E+3
4 .30E+5
4 .94E+4
1.27E+4
9.24E+1
5.36E+4
7.75E+2
.OOE+0
.OOE+0
.OOE+0
3 .95E+2
3 .95E+2
3 .95E+2
2 .61E+2
2 .61E+2
2 .61E+2
1.32E+1
1.32E+1
1.32E+1
8.32E+3
8.32E+3
8.32E+3
4 .74E+5
5.60E+6
7.75E+2
2 .49E+5
5.85E+6
1, 000
l.OOE+4
7.02E+5
.OOE+0
4 .09E+3
4 .30E+5
4 .94E+4
1.27E+4
9.24E+1
7.28E+4
7.75E+2
.OOE+0
.OOE+0
.OOE+0
3 .95E+2
3 .95E+2
3 .95E+2
2 .61E+2
2 .61E+2
2 .61E+2
1.32E+1
1.32E+1
1.32E+1
8.32E+3
8.32E+3
8.32E+3
4 .88E+5
5.72E+6
7.75E+2
2 .49E+5
5.97E+6
10, 000
l.OOE+4
7.02E+5
.OOE+0
4 .09E+3
4 .30E+5
4 .94E+4
1.27E+4
9.24E+1
7.33E+4
7.75E+2
.OOE+0
.OOE+0
.OOE+0
3 .95E+2
3 .95E+2
3 .95E+2
2 .61E+2
2 .61E+2
2 .61E+2
1.32E+1
1.32E+1
1.32E+1
8.32E+3
8.32E+3
8.32E+3
4 .88E+5
5.72E+6
7.75E+2
2 .49E+5
5.97E+6
100.00 ||
100
6 .90E+3
6 .67E+5
.OOE+0
1.33E+3
3 .24E+5
4 .26E+4
.OOE+0
.OOE+0
3 .98E+4
7.15E+2
.OOE+0
.OOE+0
.OOE+0
3 .38E+2
3 .38E+2
3 .38E+2
2 .25E+2
2 .25E+2
2 .25E+2
9.84E+0
9.84E+0
9.84E+0
6 .50E+3
6 .50E+3
6 .50E+3
3 .82E+5
4 .65E+6
7.15E+2
2 .OOE+5
4 .85E+6
1, 000
6 .90E+3
6 .75E+5
.OOE+0
1.33E+3
3 .24E+5
4 .26E+4
.OOE+0
.OOE+0
5.26E+4
7.15E+2
.OOE+0
.OOE+0
.OOE+0
3 .38E+2
3 .38E+2
3 .38E+2
2 .25E+2
2 .25E+2
2 .25E+2
9.84E+0
9.84E+0
9.84E+0
6 .50E+3
6 .50E+3
6 .50E+3
4 .66E+5
5.25E+6
7.15E+2
2 .OOE + 5
5.45E+6
1
10,000
1
1
6 .90E+3
6 .75E+5
.OOE+0
1.33E+3
3 .24E+5
4 .26E+4
.OOE+0
.OOE+0
5.31E+4
7.15E+2
.OOE+0
.OOE+0
.OOE+0
3 .38E+2
3 .38E+2
3 .38E+2
2 .25E+2
2 .25E+2
2 .25E+2
9.84E+0
9.84E+0
9.84E+0
6 .50E+3
6 .50E+3
6 .50E+3
4 .66E+5
5.25E+6
7.15E+2
2 .OOE+5
5.45E+6
-------
Table 3
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCERS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
.10
100
5.65E-1
1.85E+2
2 .46E-1
4 .31E-1
1.48E+1
1.74E+1
2 .68E+0
5.37E-2
1.56E+0
2 .99E-2
2 .62E-4
2 .34E-4
1.94E-4
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
2 .15E-2
2 .03E-2
1.83E-2
1.19E-1
1.19E-1
1.17E-1
8.32E+0
6 .57E+2
3 .18E-2
5.77E+0
6 .63E+2
1
1, 000
6 .17E-1
1.80E+3
2 .73E-1
2 .51E+0
1.62E+1
1.18E+2
1.87E+1
4 .63E-1
5.13E+0
9.31E-2
1.58E-3
1.04E-3
5.64E-4
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.66E-1
1.18E-1
6 .71E-2
1.18E+0
1.17E+0
1.12E+0
7.48E+1
5.03E+3
1.02E-1
3 .03E+1
5.06E+3
10, 000
6 .17E-1
1.42E+4
2 .73E-1
9.88E+0
1.62E+1
1.12E+3
1.22E+2
2 .87E+0
5.81E+0
9.60E-2
4 .32E-3
2 .02E-3
1.07E-2
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
2 .13E+0
1.19E+0
1.83E+0
1.11E+1
1.01E+1
8.14E+0
1.75E+2
4 .10E+4
1.44E-1
2 .42E+2
4 .12E+4
.50
100
5.53E-1
1.85E+2
2 .45E-1
4 .27E-1
1.48E+1
1.74E+1
2 .62E+0
5.10E-2
1.56E+0
2 .99E-2
2 .10E-4
1.88E-4
1.56E-4
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
1.62E-2
1.54E-2
1.38E-2
1.19E-1
1.19E-1
1.17E-1
8.32E+0
6 .57E+2
3 .14E-2
5.71E+0
6 .63E+2
1, 000
6 .04E-1
1.80E+3
2 .72E-1
2 .49E + 0
1.61E+1
1.18E+2
1.82E+1
4 .40E-1
5.13E+0
9.31E-2
1.27E-3
8.32E-4
4 .53E-4
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.26E-1
8.95E-2
5.08E-2
1.18E+0
1.17E+0
1.12E+0
7.47E+1
5.02E+3
l.OOE-1
2 .99E+1
5.05E+3
10, 000
6 .04E-1
1.42E+4
2 .72E-1
9.81E+0
1.61E+1
1.12E+3
1.19E+2
2 .72E+0
5.81E+0
9.60E-2
3 .47E-3
1.62E-3
8.55E-3
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.62E+0
9.02E-1
1.38E+0
1.11E+1
1.01E+1
8.14E+0
1.75E+2
4 .10E+4
1.35E-1
2 .36E+2
4 .12E+4
1. 00
100
5.45E-1
1.85E+2
2 .42E-1
4 .25E-1
1.47E+1
1.74E+1
2 .54E+0
4 .84E-2
1.56E+0
2 .99E-2
1.47E-4
1.31E-4
1.09E-4
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
1.38E-2
1.30E-2
1.17E-2
1.19E-1
1.19E-1
1.17E-1
8.31E+0
6 .57E+2
3 .10E-2
5.67E+0
6 .62E+2
1, 000
5.95E-1
1.80E+3
2 .69E-1
2 .47E+0
1.61E+1
1.18E+2
1.75E+1
4 .18E-1
5.13E+0
9.31E-2
8.84E-4
5.81E-4
3 .16E-4
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.06E-1
7.58E-2
4 .30E-2
1.18E+0
1.17E+0
1.12E+0
7.47E+1
5.02E+3
9.82E-2
2 .97E+1
5.05E+3
10, 000
5.95E-1
1.42E+4
2 .69E-1
9.75E+0
1.61E+1
1.12E+3
1.15E+2
2 .58E+0
5.81E+0
9.60E-2
2 .42E-3
1.13E-3
5.97E-3
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.37E+0
7.65E-1
1.17E+0
1.11E+1
1.01E+1
8.14E+0
1.75E+2
4 .10E+4
1.23E-1
2 .34E+2
4 .12E+4
3 .00
100
5.23E-1
1.85E+2
2 .21E-1
4 .18E-1
1.46E+1
1.74E+1
2 .34E+0
4 .21E-2
1.55E+0
2 .98E-2
2 .89E-5
2 .58E-5
2 .14E-5
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
9.58E-3
9.07E-3
8.16E-3
1.19E-1
1.19E-1
1.17E-1
8.29E+0
6 .56E+2
3 .01E-2
5.62E+0
6 .61E+2
1, 000
5.71E-1
1.80E+3
2 .45E-1
2 .43E+0
1.59E+1
1.18E+2
1.60E+1
3 .63E-1
5.12E+0
9.31E-2
1.74E-4
1.15E-4
6 .23E-5
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
7.41E-2
5.28E-2
2 .99E-2
1.18E+0
1.17E+0
1.12E+0
7.45E+1
5.02E+3
9.41E-2
2 .94E+1
5.05E+3
10, 000
5.71E-1
1.42E+4
2 .45E-1
9.59E+0
1.59E+1
1.12E+3
1.04E+2
2 .25E+0
5.80E+0
9.59E-2
4 .77E-4
2 .23E-4
1.18E-3
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
9.53E-1
5.32E-1
8.15E-1
1.11E+1
1.01E+1
8.14E+0
1.75E+2
4 .09E+4
1.01E-1
2 .29E+2
4 .12E+4
5.00 ||
100
5.04E-1
1.85E+2
1.95E-1
4 .13E-1
1.44E+1
1.73E+1
2 .22E+0
3 .78E-2
1.55E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
7.22E-3
6 .84E-3
6 .15E-3
1.19E-1
1.18E-1
1.17E-1
8.27E+0
6 .55E+2
2 .98E-2
5.59E+0
6 .61E+2
1, 000
5.51E-1
1.80E+3
2 .17E-1
2 .40E+0
1.57E+1
1.18E+2
1.50E+1
3 .26E-1
5.10E+0
9.31E-2
.OOE+0
.OOE+0
.OOE+0
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
5.58E-2
3 .98E-2
2 .26E-2
1.18E+0
1.16E+0
1.12E+0
7.44E+1
5.02E+3
9.31E-2
2 .92E+1
5.05E+3
1
10,000
1
1
5.51E-1
1.42E+4
2 .17E-1
9.47E+0
1.57E+1
1.12E+3
9.78E+1
2 .02E+0
5.77E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
7.18E-1
4 .01E-1
6 .14E-1
1.11E+1
1.01E+1
8.13E+0
1.74E+2
4 .09E+4
9.59E-2
2 .26E+2
4 .12E+4
-------
Table 3 Continued
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCERS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
10. 00
100
4 .73E-1
1.85E+2
1.72E-1
4 .03E-1
1.41E+1
1.73E+1
2 .03E+0
3 .16E-2
1.53E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .30E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
3 .43E-3
3 .25E-3
2 .92E-3
1.19E-1
1.18E-1
1.16E-1
8.22E+0
6 .53E+2
2 .98E-2
5.53E+0
6 .59E+2
1
1, 000
5.16E-1
1.80E+3
1.91E-1
2 .35E+0
1.54E+1
1.17E+2
1.35E+1
2 .72E-1
5.01E+0
9.31E-2
.OOE+0
.OOE+0
.OOE+0
3 .50E-3
3 .45E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
2 .65E-2
1.89E-2
1.07E-2
1.18E+0
1.16E+0
1.12E+0
7.41E+1
5.01E+3
9.31E-2
2 .88E+1
5.04E+3
10, 000
5.16E-1
1.42E+4
1.91E-1
9.25E+0
1.54E+1
1.12E+3
8.78E+1
1.69E+0
5.67E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .50E-3
3 .45E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
3 .41E-1
1.91E-1
2 .92E-1
1.11E+1
l.OOE+1
8.11E+0
1.73E+2
4 .09E+4
9.59E-2
2 .21E+2
4 .11E+4
15.00
100
4 .51E-1
1.85E+2
1.53E-1
3 .97E-1
1.38E+1
1.73E+1
1.87E+0
2 .65E-2
1.52E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .30E-3
3 .26E-3
3 .19E-3
4 .03E-2
3 .95E-2
3 .85E-2
1.42E-3
1.34E-3
1.21E-3
1.19E-1
1.18E-1
1.16E-1
8.18E+0
6 .51E+2
2 .98E-2
5.49E+0
6 .57E+2
1, 000
4 .92E-1
1.79E+3
1.70E-1
2 .31E+0
1.51E+1
1.17E+2
1.24E+1
2 .29E-1
4 .89E+0
9.31E-2
.OOE+0
.OOE+0
.OOE+0
3 .49E-3
3 .45E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.10E-2
7.81E-3
4 .43E-3
1.18E+0
1.16E+0
1.12E+0
7.38E+1
5.00E+3
9.31E-2
2 .86E+1
5.03E+3
10, 000
4 .92E-1
1.42E+4
1.70E-1
9.12E+0
1.51E+1
1.12E+3
8.05E+1
1.42E+0
5.52E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .49E-3
3 .45E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.41E-1
7.89E-2
1.21E-1
1.10E+1
l.OOE+1
8.09E+0
1.73E+2
4 .08E+4
9.59E-2
2 .18E+2
4 .11E+4
25. 00
100
4 .20E-1
1.85E+2
1.15E-1
3 .86E-1
1.33E+1
1.72E+1
1.45E+0
2 .17E-2
1.51E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .29E-3
3 .25E-3
3 .18E-3
4 .02E-2
3 .95E-2
3 .84E-2
9.22E-4
8.73E-4
7.86E-4
1.18E-1
1.17E-1
1.15E-1
8.12E+0
6 .49E+2
2 .98E-2
5.47E+0
6 .54E+2
1, 000
4 .58E-1
1.79E+3
1.27E-1
2 .25E+0
1.45E+1
1.17E+2
9.61E+0
1.87E-1
4 .62E+0
9.30E-2
.OOE+0
.OOE+0
.OOE+0
3 .48E-3
3 .44E-3
3 .34E-3
4 .44E-2
4 .37E-2
4 .21E-2
7.13E-3
5.08E-3
2 .88E-3
1.17E+0
1.15E+0
1.11E+0
7.31E+1
4 .99E+3
9.30E-2
2 .84E+1
5.02E+3
10, 000
4 .58E-1
1.41E+4
1.27E-1
8.85E+0
1.45E+1
1.11E+3
6 .25E+1
1.16E+0
5.20E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .48E-3
3 .44E-3
3 .34E-3
4 .44E-2
4 .37E-2
4 .21E-2
9.19E-2
5.13E-2
7.86E-2
1.10E+1
9.94E+0
8.04E+0
1.71E+2
4 .07E+4
9.59E-2
2 .16E+2
4 .09E+4
75.00
100
3 .32E-1
1.85E+2
2 .97E-2
3 .27E-1
1.11E+1
1.69E+1
6 .09E-1
1.02E-2
1.45E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .26E-3
3 .23E-3
3 .15E-3
3 .97E-2
3 .90E-2
3 .80E-2
7.36E-4
6 .97E-4
6 .27E-4
1.14E-1
1.14E-1
1.12E-1
7.68E+0
6 .35E+2
2 .98E-2
5.35E+0
6 .41E+2
1, 000
3 .63E-1
1.79E+3
3 .30E-2
1.91E+0
1.21E+1
1.16E+2
4 .08E+0
8.76E-2
3 .53E+0
9.29E-2
.OOE+0
.OOE+0
.OOE+0
3 .45E-3
3 .41E-3
3 .32E-3
4 .39E-2
4 .32E-2
4 .16E-2
5.69E-3
4 .06E-3
2 .30E-3
1.13E+0
1.12E+0
1.08E+0
6 .99E+1
4 .93E+3
9.29E-2
2 .76E+1
4 .96E+3
10, 000
3 .63E-1
1.40E+4
3 .30E-2
7.51E+0
1.21E+1
1.11E+3
2 .66E+1
5.42E-1
3 .92E+0
9.58E-2
.OOE+0
.OOE+0
.OOE+0
3 .45E-3
3 .41E-3
3 .32E-3
4 .39E-2
4 .32E-2
4 .16E-2
7.34E-2
4 .10E-2
6 .27E-2
1.06E+1
9.65E+0
7.80E+0
1.64E+2
4 .03E+4
9.58E-2
2 .10E+2
4 .05E+4
100.00 ||
100
2 .91E-1
1.84E+2
2 .29E-2
2 .98E-1
1.07E+1
1.67E+1
4 .82E-1
7.12E-3
1.42E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .25E-3
3 .21E-3
3 .14E-3
3 .94E-2
3 .87E-2
3 .77E-2
6 .83E-4
6 .47E-4
5.82E-4
1.11E-1
1.11E-1
1.09E-1
7.62E+0
6 .31E+2
2 .98E-2
5.27E+0
6 .36E+2
1, 000
3 .18E-1
1.79E+3
2 .54E-2
1.74E+0
1.17E+1
1.15E+2
3 .24E + 0
6 .14E-2
3 .25E+0
9.28E-2
.OOE+0
.OOE+0
.OOE+0
3 .44E-3
3 .40E-3
3 .30E-3
4 .36E-2
4 .29E-2
4 .13E-2
5.28E-3
3 .77E-3
2 .14E-3
1.10E+0
1.09E+0
1.05E+0
6 .89E+1
4 .90E+3
9.28E-2
2 .69E+1
4 .93E+3
1
10,000
1
1
3 .18E-1
1.40E+4
2 .54E-2
6 .84E+0
1.17E+1
1.10E+3
2 .11E+1
3 .80E-1
3 .59E+0
9.57E-2
.OOE+0
.OOE+0
.OOE+0
3 .44E-3
3 .40E-3
3 .30E-3
4 .36E-2
4 .29E-2
4 .13E-2
6 .81E-2
3 .80E-2
5.82E-2
1.04E+1
9.39E+0
7.59E+0
1.61E+2
4 .01E+4
9.57E-2
2 .04E+2
4 .03E+4
-------
Table 4
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCERS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
.10
100
5.59E-1
1.85E+2
2 .46E-1
4 .29E-1
1.48E+1
1.74E+1
2 .66E+0
5.19E-2
1.56E+0
2 .99E-2
2 .38E-4
2 .13E-4
1.77E-4
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
1.71E-2
1.62E-2
1.46E-2
1.19E-1
1.19E-1
1.17E-1
8.32E+0
6 .57E+2
3 .16E-2
5.72E+0
6 .63E+2
1
1, 000
6 .10E-1
1.80E+3
2 .73E-1
2 .50E+0
1.61E+1
1.18E+2
1.85E+1
4 .48E-1
5.13E+0
9.31E-2
1.44E-3
9.44E-4
5.14E-4
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.32E-1
9.43E-2
5.35E-2
1.18E+0
1.17E+0
1.12E+0
7.47E+1
5.03E+3
1.01E-1
2 .99E+1
5.06E+3
10, 000
6 .10E-1
1.42E+4
2 .73E-1
9.84E+0
1.61E+1
1.12E+3
1.21E+2
2 .77E+0
5.81E+0
9.60E-2
3 .93E-3
1.84E-3
9.71E-3
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.70E+0
9.51E-1
1.46E+0
1.11E+1
1.01E+1
8.14E+0
1.75E+2
4 .10E+4
1.40E-1
2 .37E+2
4 .12E+4
.50
100
5.39E-1
1.85E+2
2 .39E-1
4 .23E-1
1.47E+1
1.74E+1
2 .45E+0
4 .57E-2
1.56E+0
2 .98E-2
1.39E-4
1.24E-4
1.03E-4
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
1.13E-2
1.07E-2
9.61E-3
1.19E-1
1.19E-1
1.17E-1
8.31E+0
6 .56E+2
3 .09E-2
5.64E+0
6 .62E+2
1, 000
5.89E-1
1.80E+3
2 .65E-1
2 .46E + 0
1.60E+1
1.18E+2
1.68E+1
3 .95E-1
5.13E+0
9.31E-2
8.38E-4
5.51E-4
3 .OOE-4
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
8.72E-2
6 .21E-2
3 .53E-2
1.18E+0
1.17E+0
1.12E+0
7.46E+1
5.02E+3
9.79E-2
2 .95E+1
5.05E+3
10, 000
5.89E-1
1.42E+4
2 .65E-1
9.70E+0
1.60E+1
1.12E+3
1.10E+2
2 .44E+0
5.81E+0
9.59E-2
2 .30E-3
1.07E-3
5.67E-3
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.12E+0
6 .27E-1
9.60E-1
1.11E+1
1.01E+1
8.14E+0
1.75E+2
4 .10E+4
1.22E-1
2 .31E+2
4 .12E+4
1. 00
100
5.25E-1
1.85E+2
2 .24E-1
4 .18E-1
1.46E+1
1.74E+1
2 .31E+0
4 .12E-2
1.56E+0
2 .98E-2
6 .81E-5
6 .09E-5
5.05E-5
3 .31E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
8.35E-3
7.91E-3
7.12E-3
1.19E-1
1.19E-1
1.17E-1
8.29E+0
6 .56E+2
3 .03E-2
5.60E+0
6 .61E+2
1, 000
5.73E-1
1.80E+3
2 .48E-1
2 .43E+0
1.59E+1
1.18E+2
1.57E+1
3 .56E-1
5.13E+0
9.31E-2
4 .11E-4
2 .70E-4
1.47E-4
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
6 .46E-2
4 .60E-2
2 .61E-2
1.18E+0
1.17E+0
1.12E+0
7.45E+1
5.02E+3
9.54E-2
2 .93E+1
5.05E+3
10, 000
5.73E-1
1.42E+4
2 .48E-1
9.58E+0
1.59E+1
1.12E+3
1.03E+2
2 .20E+0
5.80E+0
9.59E-2
1.12E-3
5.25E-4
2 .77E-3
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
8.31E-1
4 .64E-1
7.11E-1
1.11E+1
1.01E+1
8.14E+0
1.74E+2
4 .09E+4
1.08E-1
2 .27E+2
4 .12E+4
3 .00
100
4 .81E-1
1.85E+2
1.78E-1
4 .04E-1
1.42E+1
1.73E+1
2 .03E+0
3 .14E-2
1.56E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .30E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .96E-2
3 .85E-2
2 .38E-3
2 .26E-3
2 .03E-3
1.19E-1
1.18E-1
1.16E-1
8.23E+0
6 .54E+2
2 .98E-2
5.52E+0
6 .59E+2
1, 000
5.26E-1
1.80E+3
1.97E-1
2 .35E+0
1.55E+1
1.18E+2
1.35E+1
2 .71E-1
5.08E+0
9.31E-2
.OOE+0
.OOE+0
.OOE+0
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
1.84E-2
1.31E-2
7.45E-3
1.18E+0
1.16E+0
1.12E+0
7.41E+1
5.01E+3
9.31E-2
2 .87E+1
5.04E+3
10, 000
5.26E-1
1.42E+4
1.97E-1
9.27E+0
1.55E+1
1.12E+3
8.78E+1
1.67E+0
5.75E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .50E-3
3 .46E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
2 .37E-1
1.33E-1
2 .03E-1
1.11E+1
l.OOE+1
8.11E+0
1.74E+2
4 .09E+4
9.59E-2
2 .20E+2
4 .11E+4
5.00 ||
100
4 .55E-1
1.85E+2
1.57E-1
3 .97E-1
1.39E+1
1.73E+1
1.79E+0
2 .48E-2
1.56E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .30E-3
3 .27E-3
3 .20E-3
4 .03E-2
3 .95E-2
3 .85E-2
1.01E-3
9.54E-4
8.58E-4
1.19E-1
1.18E-1
1.16E-1
8.17E+0
6 .52E+2
2 .98E-2
5.49E+0
6 .57E+2
1, 000
4 .97E-1
1.79E+3
1.75E-1
2 .31E + 0
1.52E+1
1.17E+2
1.19E+1
2 .14E-1
4 .99E+0
9.30E-2
.OOE+0
.OOE+0
.OOE+0
3 .49E-3
3 .45E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
7.79E-3
5.55E-3
3 .15E-3
1.18E+0
1.16E+0
1.12E+0
7.39E+1
5.00E+3
9.30E-2
2 .85E+1
5.03E+3
1
10,000
1
1
4 .97E-1
1.42E+4
1.75E-1
9.11E+0
1.52E+1
1.12E+3
7.72E+1
1.32E+0
5.65E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .49E-3
3 .45E-3
3 .36E-3
4 .45E-2
4 .38E-2
4 .22E-2
l.OOE-1
5.60E-2
8.57E-2
1.10E+1
l.OOE+1
8.08E+0
1.73E+2
4 .08E+4
9.59E-2
2 .18E+2
4 .10E+4
-------
Table 4 Continued
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCERS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
10. 00
100
4 .13E-1
1.85E+2
1.05E-1
3 .79E-1
1.31E+1
1.72E+1
1.21E+0
1.81E-2
1.55E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .29E-3
3 .25E-3
3 .18E-3
4 .02E-2
3 .95E-2
3 .84E-2
8.50E-4
8.05E-4
7.24E-4
1.17E-1
1.17E-1
1.15E-1
8.10E+0
6 .48E+2
2 .98E-2
5.45E+0
6 .53E+2
1
1, 000
4 .51E-1
1.79E+3
1.16E-1
2 .21E+0
1.43E+1
1.17E+2
8.03E+0
1.56E-1
4 .70E+0
9.30E-2
.OOE+0
.OOE+0
.OOE+0
3 .48E-3
3 .44E-3
3 .34E-3
4 .44E-2
4 .37E-2
4 .21E-2
6 .58E-3
4 .69E-3
2 .66E-3
1.17E+0
1.15E+0
1.11E+0
7.30E+1
4 .99E+3
9.30E-2
2 .83E+1
5.01E+3
10, 000
4 .51E-1
1.41E+4
1.16E-1
8.69E+0
1.43E+1
1.11E+3
5.22E+1
9.66E-1
5.31E+0
9.59E-2
.OOE+0
.OOE+0
.OOE+0
3 .48E-3
3 .44E-3
3 .34E-3
4 .44E-2
4 .37E-2
4 .21E-2
8.47E-2
4 .73E-2
7.24E-2
1.09E+1
9.90E+0
8.01E+0
1.71E+2
4 .07E+4
9.59E-2
2 .16E+2
4 .09E+4
15.00
100
3 .86E-1
1.85E+2
6 .48E-2
3 .61E-1
1.23E+1
1.71E+1
8.57E-1
1.31E-2
1.53E+0
2 .98E-2
.OOE+0
.OOE+0
.OOE+0
3 .28E-3
3 .24E-3
3 .17E-3
4 .OOE-2
3 .93E-2
3 .83E-2
7.80E-4
7.40E-4
6 .65E-4
1.16E-1
1.16E-1
1.14E-1
7.94E+0
6 .43E+2
2 .98E-2
5.42E+0
6 .49E+2
1, 000
4 .22E-1
1.79E+3
7.19E-2
2 .10E+0
1.35E+1
1.17E+2
5.71E+0
1.13E-1
4 .40E+0
9.29E-2
.OOE+0
.OOE+0
.OOE+0
3 .47E-3
3 .43E-3
3 .33E-3
4 .43E-2
4 .35E-2
4 .19E-2
6 .04E-3
4 .30E-3
2 .44E-3
1.15E+0
1.14E+0
1.10E+0
7.23E+1
4 .97E+3
9.29E-2
2 .80E+1
5.00E+3
10, 000
4 .22E-1
1.41E+4
7.19E-2
8.28E+0
1.35E+1
1.11E+3
3 .71E+1
6 .97E-1
4 .96E+0
9.58E-2
.OOE+0
.OOE+0
.OOE+0
3 .47E-3
3 .43E-3
3 .33E-3
4 .43E-2
4 .35E-2
4 .19E-2
7.78E-2
4 .35E-2
6 .65E-2
1.08E+1
9.81E+0
7.93E+0
1.69E+2
4 .06E+4
9.58E-2
2 .14E+2
4 .08E+4
25. 00
100
3 .43E-1
1.85E+2
3 .11E-2
3 .25E-1
1.11E+1
1.69E+1
5.65E-1
8.92E-3
1.51E+0
2 .97E-2
.OOE+0
.OOE+0
.OOE+0
3 .26E-3
3 .23E-3
3 .16E-3
3 .97E-2
3 .90E-2
3 .79E-2
6 .88E-4
6 .52E-4
5.86E-4
1.14E-1
1.13E-1
1.12E-1
7.67E+0
6 .36E+2
2 .97E-2
5.35E+0
6 .41E+2
1, 000
3 .75E-1
1.79E+3
3 .46E-2
1.89E+0
1.22E+1
1.16E+2
3 .79E+0
7.70E-2
3 .87E+0
9.27E-2
.OOE+0
.OOE+0
.OOE+0
3 .46E-3
3 .41E-3
3 .32E-3
4 .39E-2
4 .32E-2
4 .16E-2
5.33E-3
3 .79E-3
2 .15E-3
1.13E+0
1.12E+0
1.07E+0
7.00E+1
4 .93E+3
9.27E-2
2 .75E+1
4 .96E+3
10, 000
3 .75E-1
1.40E+4
3 .46E-2
7.45E+0
1.22E+1
1.11E+3
2 .47E+1
4 .76E-1
4 .33E+0
9.56E-2
.OOE+0
.OOE+0
.OOE+0
3 .46E-3
3 .41E-3
3 .32E-3
4 .39E-2
4 .32E-2
4 .16E-2
6 .86E-2
3 .83E-2
5.87E-2
1.06E+1
9.63E+0
7.79E+0
1.64E+2
4 .03E+4
9.56E-2
2 .10E+2
4 .06E+4
75.00
100
2 .01E-1
1.83E+2
.OOE+0
1.44E-1
9.10E+0
1.61E+1
3 .30E-2
1.62E-3
1.40E+0
2 .95E-2
.OOE+0
.OOE+0
.OOE+0
3 .14E-3
3 .11E-3
3 .04E-3
3 .79E-2
3 .72E-2
3 .62E-2
4 .76E-4
4 .51E-4
4 .06E-4
9.60E-2
9.53E-2
9.37E-2
7.33E+0
6 .11E+2
2 .95E-2
4 .82E+0
6 .16E+2
1, 000
2 .19E-1
1.77E+3
.OOE+0
8.38E-1
9.93E+0
1.13E+2
1.87E-1
1.40E-2
2 .81E+0
9.21E-2
.OOE+0
.OOE+0
.OOE+0
3 .33E-3
3 .29E-3
3 .20E-3
4 .19E-2
4 .12E-2
3 .97E-2
3 .69E-3
2 .63E-3
1.49E-3
9.52E-1
9.37E-1
9.03E-1
6 .69E + 1
4 .80E+3
9.21E-2
2 .35E+1
4 .83E+3
10, 000
2 .19E-1
1.38E+4
.OOE+0
3 .30E+0
9.93E+0
1.08E+3
1.18E+0
8.65E-2
3 .08E+0
9.49E-2
.OOE+0
.OOE+0
.OOE+0
3 .33E-3
3 .29E-3
3 .20E-3
4 .19E-2
4 .12E-2
3 .97E-2
4 .76E-2
2 .66E-2
4 .06E-2
8.93E+0
8.09E+0
6 .54E+0
1.57E+2
3 .93E+4
9.49E-2
1.76E+2
3 .95E+4
100.00 ||
100
1.71E-1
1.82E+2
.OOE+0
5.37E-2
8.08E+0
1.59E+1
.OOE+0
.OOE+0
1.35E+0
2 .95E-2
.OOE+0
.OOE+0
.OOE+0
3 .07E-3
3 .04E-3
2 .97E-3
3 .70E-2
3 .64E-2
3 .54E-2
4 .02E-4
3 .81E-4
3 .43E-4
8.93E-2
8.87E-2
8.72E-2
6 .58E+0
5.98E+2
2 .95E-2
4 .61E+0
6 .02E+2
1, 000
1.87E-1
1.76E+3
.OOE+0
3 .12E-1
8.82E+0
1.11E+2
.OOE+0
.OOE+0
2 .53E+0
9.19E-2
.OOE+0
.OOE+0
.OOE+0
3 .26E-3
3 .22E-3
3 .13E-3
4 .09E-2
4 .03E-2
3 .88E-2
3 .11E-3
2 .22E-3
1.26E-3
8.86E-1
8.72E-1
8.41E-1
6 .56E+1
4 .75E+3
9.19E-2
2 .20E+1
4 .78E+3
1
10,000
1
1
1.87E-1
1.37E+4
.OOE+0
1.23E+0
8.82E+0
1.06E+3
.OOE+0
.OOE+0
2 .75E+0
9.47E-2
.OOE+0
.OOE+0
.OOE+0
3 .26E-3
3 .22E-3
3 .13E-3
4 .09E-2
4 .03E-2
3 .88E-2
4 .02E-2
2 .25E-2
3 .43E-2
8.31E+0
7.53E+0
6 .09E+0
1.54E+2
3 .89E+4
9.47E-2
1.64E+2
3 .91E+4
-------
Table 5
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCER DEATHS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
.10
100
3 .74E-1
1.49E+2
1.63E-1
2 .79E-1
9.81E+0
1.19E+1
2 .19E+0
4 .74E-2
1.02E+0
2 .66E-2
1.70E-4
1.51E-4
1.24E-4
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
1.35E-2
1.27E-2
1.14E-2
7.90E-2
7.84E-2
7.72E-2
6 .28E+0
4 .77E+2
2 .78E-2
3 .81E+0
4 .81E+2
1
1, 000
4 .09E-1
1.45E+3
1.81E-1
1.59E+0
1.07E+1
8.05E+1
1.57E+1
4 .13E-1
3 .21E+0
8.25E-2
9.98E-4
6 .49E-4
3 .52E-4
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.05E-1
7.41E-2
4 .25E-2
7.84E-1
7.71E-1
7.43E-1
5.52E+1
3 .69E+3
8.82E-2
2 .OOE+1
3 .71E+3
10, 000
4 .09E-1
1.20E+4
1.81E-1
7.67E+0
1.07E+1
8.34E+2
1.04E+2
2 .57E+0
3 .67E+0
8.50E-2
2 .94E-3
1.42E-3
6 .58E-3
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.72E+0
9.91E-1
1.26E+0
7.35E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
1.16E-1
1.63E+2
3 .21E+4
.50
100
3 .66E-1
1.49E+2
1.62E-1
2 .77E-1
9.79E+0
1.19E+1
2 .14E+0
4 .50E-2
1.02E+0
2 .66E-2
1.37E-4
1.21E-4
9.97E-5
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
1.02E-2
9.65E-3
8.61E-3
7.90E-2
7.84E-2
7.72E-2
6 .28E+0
4 .77E+2
2 .76E-2
3 .76E+0
4 .81E+2
1, 000
4 .OOE-1
1.45E+3
1.80E-1
1.57E+0
1.07E+1
8.05E+1
1.53E+1
3 .92E-1
3 .21E+0
8.25E-2
8.01E-4
5.21E-4
2 .82E-4
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
7.91E-2
5.61E-2
3 .22E-2
7.84E-1
7.71E-1
7.43E-1
5.51E+1
3 .68E+3
8.70E-2
1.97E+1
3 .70E+3
10, 000
4 .OOE-1
1.20E+4
1.80E-1
7.62E+0
1.07E+1
8.34E+2
1.01E+2
2 .44E+0
3 .67E+0
8.50E-2
2 .36E-3
1.14E-3
5.28E-3
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.30E+0
7.50E-1
9.55E-1
7.35E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
1.10E-1
1.58E+2
3 .21E+4
1. 00
100
3 .61E-1
1.49E+2
1.61E-1
2 .75E-1
9.77E+0
1.19E+1
2 .07E+0
4 .28E-2
1.02E+0
2 .66E-2
9.55E-5
8.46E-5
6 .96E-5
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
8.67E-3
8.18E-3
7.29E-3
7.90E-2
7.84E-2
7.72E-2
6 .27E+0
4 .77E+2
2 .73E-2
3 .74E+0
4 .80E+2
1, 000
3 .94E-1
1.45E+3
1.78E-1
1.56E+0
1.06E+1
8.05E+1
1.47E+1
3 .72E-1
3 .21E+0
8.25E-2
5.60E-4
3 .64E-4
1.97E-4
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
6 .71E-2
4 .76E-2
2 .72E-2
7.84E-1
7.71E-1
7.43E-1
5.51E+1
3 .68E+3
8.57E-2
1.96E+1
3 .70E+3
10, 000
3 .94E-1
1.20E+4
1.78E-1
7.57E+0
1.06E+1
8.34E+2
9.76E+1
2 .32E+0
3 .67E+0
8.50E-2
1.65E-3
7.95E-4
3 .69E-3
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.10E+0
6 .36E-1
8.09E-1
7.35E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
1.02E-1
1.56E+2
3 .21E+4
3 .00
100
3 .47E-1
1.49E+2
1.46E-1
2 .71E-1
9.66E+0
1.19E+1
1.91E+0
3 .72E-2
1.02E+0
2 .66E-2
1.88E-5
1.67E-5
1.37E-5
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
6 .04E-3
5.69E-3
5.08E-3
7.89E-2
7.83E-2
7.72E-2
6 .26E+0
4 .76E+2
2 .67E-2
3 .71E+0
4 .80E+2
1, 000
3 .79E-1
1.45E+3
1.63E-1
1.54E+0
1.05E+1
8.05E+1
1.34E+1
3 .23E-1
3 .21E+0
8.24E-2
1.10E-4
7.17E-5
3 .89E-5
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
4 .67E-2
3 .31E-2
1.90E-2
7.84E-1
7.71E-1
7.43E-1
5.50E+1
3 .68E+3
8.31E-2
1.94E+1
3 .70E+3
10, 000
3 .79E-1
1.20E+4
1.63E-1
7.45E+0
1.05E+1
8.34E+2
8.88E+1
2 .01E+0
3 .67E+0
8.49E-2
3 .25E-4
1.57E-4
7.27E-4
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
7.66E-1
4 .42E-1
5.63E-1
7.34E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
8.83E-2
1.52E+2
3 .21E+4
5.00 ||
100
3 .34E-1
1.49E+2
1.29E-1
2 .67E-1
9.56E+0
1.19E+1
1.80E+0
3 .34E-2
1.01E+0
2 .66E-2
.OOE+0
.OOE+0
.OOE+0
2 .18E-3
2 .16E-3
2 .11E-3
2 .66E-2
2 .62E-2
2 .53E-2
4 .55E-3
4 .29E-3
3 .82E-3
7.89E-2
7.83E-2
7.71E-2
6 .24E + 0
4 .75E+2
2 .66E-2
3 .69E+0
4 .79E+2
1, 000
3 .65E-1
1.44E+3
1.44E-1
1.52E+0
1.04E+1
8.05E+1
1.26E+1
2 .91E-1
3 .20E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
3 .52E-2
2 .49E-2
1.43E-2
7.83E-1
7.70E-1
7.43E-1
5.49E+1
3 .68E+3
8.24E-2
1.93E+1
3 .70E+3
1
10,000
1
1
3 .65E-1
1.20E+4
1.44E-1
7.36E+0
1.04E+1
8.34E+2
8.33E+1
1.81E+0
3 .65E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
5.78E-1
3 .33E-1
4 .24E-1
7.34E+0
6 .64E+0
5.38E+0
1.31E+2
3 .19E+4
8.49E-2
1.50E+2
3 .21E+4
-------
Table 5 Continued
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCER DEATHS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
10. 00
100
3 .13E-1
1.48E+2
1.14E-1
2 .61E-1
9.36E+0
1.19E+1
1.64E+0
2 .79E-2
1.01E+0
2 .66E-2
.OOE+0
.OOE+0
.OOE+0
2 .18E-3
2 .16E-3
2 .11E-3
2 .66E-2
2 .62E-2
2 .53E-2
2 .16E-3
2 .04E-3
1.82E-3
7.87E-2
7.81E-2
7.69E-2
6 .21E+0
4 .74E+2
2 .66E-2
3 .65E+0
4 .78E+2
1
1, 000
3 .42E-1
1.44E+3
1.27E-1
1.48E+0
1.02E+1
8.04E+1
1.13E+1
2 .43E-1
3 .14E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.67E-2
1.19E-2
6 .79E-3
7.81E-1
7.68E-1
7.41E-1
5.46E+1
3 .67E+3
8.24E-2
1.91E+1
3 .69E+3
10, 000
3 .42E-1
1.20E+4
1.27E-1
7.18E+0
1.02E+1
8.33E+2
7.48E+1
1.51E+0
3 .58E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
2 .74E-1
1.58E-1
2 .02E-1
7.32E+0
6 .62E+0
5.36E+0
1.31E+2
3 .19E+4
8.49E-2
1.47E+2
3 .20E+4
15.00
100
2 .99E-1
1.48E+2
1.02E-1
2 .57E-1
9.18E+0
1.19E+1
1.51E+0
2 .34E-2
9.99E-1
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .18E-3
2 .16E-3
2 .11E-3
2 .66E-2
2 .62E-2
2 .53E-2
8.93E-4
8.42E-4
7.51E-4
7.85E-2
7.79E-2
7.67E-2
6 .17E+0
4 .73E+2
2 .65E-2
3 .63E+0
4 .77E+2
1, 000
3 .26E-1
1.44E+3
1.13E-1
1.46E+0
9.99E+0
8.03E+1
1.04E+1
2 .04E-1
3 .07E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .94E-2
2 .89E-2
2 .78E-2
6 .91E-3
4 .90E-3
2 .81E-3
7.79E-1
7.66E-1
7.39E-1
5.45E+1
3 .67E+3
8.24E-2
1.89E+1
3 .69E+3
10, 000
3 .26E-1
1.19E+4
1.13E-1
7.08E+0
9.99E+0
8.33E+2
6 .85E+1
1.27E+0
3 .49E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .94E-2
2 .89E-2
2 .78E-2
1.14E-1
6 .56E-2
8.34E-2
7.30E+0
6 .61E+0
5.35E+0
1.30E+2
3 .18E+4
8.49E-2
1.44E+2
3 .20E+4
25. 00
100
2 .78E-1
1.48E+2
7.60E-2
2 .50E-1
8.80E+0
1.18E+1
1.18E+0
1.91E-2
9.89E-1
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .17E-3
2 .15E-3
2 .10E-3
2 .66E-2
2 .62E-2
2 .53E-2
5.81E-4
5.48E-4
4 .89E-4
7.80E-2
7.74E-2
7.62E-2
6 .13E+0
4 .71E+2
2 .65E-2
3 .61E+0
4 .75E+2
1, 000
3 .04E-1
1.44E+3
8.44E-2
1.42E+0
9.58E+0
8.02E+1
8.08E+0
1.66E-1
2 .90E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .30E-3
2 .27E-3
2 .21E-3
2 .94E-2
2 .89E-2
2 .77E-2
4 .49E-3
3 .19E-3
1.83E-3
7.74E-1
7.61E-1
7.34E-1
5.39E+1
3 .66E+3
8.24E-2
1.88E+1
3 .68E+3
10, 000
3 .04E-1
1.19E+4
8.44E-2
6 .87E+0
9.58E+0
8.32E+2
5.33E+1
1.04E+0
3 .29E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .30E-3
2 .27E-3
2 .21E-3
2 .94E-2
2 .89E-2
2 .77E-2
7.39E-2
4 .27E-2
5.43E-2
7.25E+0
6 .57E+0
5.32E+0
1.29E+2
3 .17E+4
8.49E-2
1.43E+2
3 .19E+4
75.00
100
2 .20E-1
1.48E+2
1.97E-2
2 .12E-1
7.33E+0
1.16E+1
4 .94E-1
8.97E-3
9.49E-1
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .15E-3
2 .13E-3
2 .09E-3
2 .62E-2
2 .58E-2
2 .50E-2
4 .64E-4
4 .37E-4
3 .90E-4
7.57E-2
7.51E-2
7.40E-2
5.79E+0
4 .62E+2
2 .65E-2
3 .54E+0
4 .65E+2
1, 000
2 .41E-1
1.44E+3
2 .19E-2
1.21E+0
7.98E+0
7.95E+1
3 .43E+0
7.80E-2
2 .23E+0
8.23E-2
.OOE+0
.OOE+0
.OOE+0
2 .28E-3
2 .25E-3
2 .19E-3
2 .90E-2
2 .85E-2
2 .74E-2
3 .59E-3
2 .55E-3
1.46E-3
7.51E-1
7.39E-1
7.12E-1
5.16E+1
3 .61E+3
8.23E-2
1.83E+1
3 .63E+3
10, 000
2 .41E-1
1.18E+4
2 .19E-2
5.83E+0
7.98E+0
8.25E+2
2 .26E+1
4 .86E-1
2 .49E+0
8.48E-2
.OOE+0
.OOE+0
.OOE+0
2 .28E-3
2 .25E-3
2 .19E-3
2 .90E-2
2 .85E-2
2 .74E-2
5.90E-2
3 .41E-2
4 .33E-2
7.04E+0
6 .37E+0
5.16E+0
1.23E+2
3 .14E+4
8.48E-2
1.39E+2
3 .16E+4
100.00 ||
100
1.93E-1
1.48E+2
1.52E-2
1.93E-1
7.09E+0
1.15E+1
3 .91E-1
6 .29E-3
9.30E-1
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .14E-3
2 .12E-3
2 .08E-3
2 .60E-2
2 .56E-2
2 .48E-2
4 .30E-4
4 .06E-4
3 .62E-4
7.37E-2
7.31E-2
7.20E-2
5.75E+0
4 .58E+2
2 .65E-2
3 .48E+0
4 .62E+2
1, 000
2 .11E-1
1.44E+3
1.69E-2
1.10E+0
7.71E+0
7.90E+1
2 .72E+0
5.47E-2
2 .06E+0
8.22E-2
.OOE+0
.OOE+0
.OOE+0
2 .27E-3
2 .24E-3
2 .18E-3
2 .88E-2
2 .83E-2
2 .72E-2
3 .33E-3
2 .36E-3
1.35E-3
7.31E-1
7.19E-1
6 .93E-1
5.08E+1
3 .60E+3
8.22E-2
1.78E+1
3 .61E+3
1
10,000
1
1
2 .11E-1
1.18E+4
1.69E-2
5.31E+0
7.71E+0
8.21E+2
1.80E+1
3 .41E-1
2 .29E+0
8.47E-2
.OOE+0
.OOE+0
.OOE+0
2 .27E-3
2 .24E-3
2 .18E-3
2 .88E-2
2 .83E-2
2 .72E-2
5.48E-2
3 .16E-2
4 .02E-2
6 .85E+0
6 .20E+0
5.02E+0
1.22E+2
3 .13E+4
8.47E-2
1.35E+2
3 .14E+4
-------
Table 6
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCER DEATHS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
.10
100
3 .70E-1
1.49E+2
1.63E-1
2 .78E-1
9.80E+0
1.19E+1
2 .17E+0
4 .58E-2
1.02E+0
2 .66E-2
1.55E-4
1.38E-4
1.13E-4
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
1.08E-2
1.02E-2
9.07E-3
7.90E-2
7.84E-2
7.72E-2
6 .28E+0
4 .77E+2
2 .77E-2
3 .77E+0
4 .81E+2
1
1, 000
4 .04E-1
1.45E+3
1.81E-1
1.58E+0
1.07E+1
8.05E+1
1.56E+1
3 .99E-1
3 .21E+0
8.25E-2
9.09E-4
5.92E-4
3 .20E-4
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
8.34E-2
5.92E-2
3 .39E-2
7.84E-1
7.71E-1
7.43E-1
5.52E+1
3 .69E+3
8.77E-2
1.98E+1
3 .71E+3
10, 000
4 .04E-1
1.20E+4
1.81E-1
7.64E+0
1.07E+1
8.34E+2
1.03E+2
2 .48E+0
3 .67E+0
8.50E-2
2 .68E-3
1.29E-3
6 .OOE-3
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.37E+0
7.90E-1
1.01E+0
7.35E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
1.13E-1
1.59E+2
3 .21E+4
.50
100
3 .57E-1
1.49E+2
1.58E-1
2 .74E-1
9.75E+0
1.19E+1
2 .OOE+0
4 .04E-2
1.02E+0
2 .66E-2
9.06E-5
8.03E-5
6 .60E-5
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
7.11E-3
6 .70E-3
5.98E-3
7.90E-2
7.84E-2
7.72E-2
6 .27E+0
4 .76E+2
2 .72E-2
3 .72E+0
4 .80E+2
1, 000
3 .90E-1
1.45E+3
1.76E-1
1.56E+0
1.06E+1
8.05E+1
1.42E+1
3 .51E-1
3 .21E+0
8.25E-2
5.31E-4
3 .45E-4
1.87E-4
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
5.50E-2
3 .90E-2
2 .23E-2
7.84E-1
7.71E-1
7.43E-1
5.51E+1
3 .68E+3
8.55E-2
1.95E+1
3 .70E+3
10, 000
3 .90E-1
1.20E+4
1.76E-1
7.53E+0
1.06E+1
8.34E+2
9.38E+1
2 .19E+0
3 .67E+0
8.49E-2
1.56E-3
7.54E-4
3 .50E-3
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
9.03E-1
5.21E-1
6 .63E-1
7.34E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
1.01E-1
1.54E+2
3 .21E+4
1. 00
100
3 .48E-1
1.49E+2
1.48E-1
2 .71E-1
9.67E+0
1.19E+1
1.88E+0
3 .64E-2
1.02E+0
2 .66E-2
4 .44E-5
3 .93E-5
3 .23E-5
2 .18E-3
2 .16E-3
2 .12E-3
2 .66E-2
2 .62E-2
2 .53E-2
5.26E-3
4 .96E-3
4 .43E-3
7.89E-2
7.83E-2
7.72E-2
6 .26E+0
4 .76E+2
2 .69E-2
3 .70E+0
4 .80E+2
1, 000
3 .80E-1
1.45E+3
1.65E-1
1.54E+0
1.05E+1
8.05E+1
1.32E+1
3 .17E-1
3 .21E+0
8.24E-2
2 .60E-4
1.69E-4
9.16E-5
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
4 .07E-2
2 .89E-2
1.65E-2
7.84E-1
7.71E-1
7.43E-1
5.50E+1
3 .68E+3
8.39E-2
1.93E+1
3 .70E+3
10, 000
3 .80E-1
1.20E+4
1.65E-1
7.44E+0
1.05E+1
8.34E+2
8.75E+1
1.97E+0
3 .67E+0
8.49E-2
7.66E-4
3 .69E-4
1.71E-3
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
6 .68E-1
3 .86E-1
4 .91E-1
7.34E+0
6 .65E+0
5.38E+0
1.32E+2
3 .19E+4
9.30E-2
1.51E+2
3 .21E+4
3 .00
100
3 .19E-1
1.48E+2
1.18E-1
2 .62E-1
9.42E+0
1.19E+1
1.64E+0
2 .77E-2
1.02E+0
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .18E-3
2 .16E-3
2 .11E-3
2 .66E-2
2 .62E-2
2 .53E-2
1.50E-3
1.42E-3
1.26E-3
7.87E-2
7.81E-2
7.69E-2
6 .21E+0
4 .74E+2
2 .65E-2
3 .64E+0
4 .78E+2
1, 000
3 .48E-1
1.44E+3
1.31E-1
1.49E+0
1.03E+1
8.04E+1
1.13E+1
2 .41E-1
3 .18E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.16E-2
8.24E-3
4 .72E-3
7.81E-1
7.69E-1
7.41E-1
5.47E+1
3 .67E+3
8.24E-2
1.90E+1
3 .69E+3
10, 000
3 .48E-1
1.20E+4
1.31E-1
7.20E+0
1.03E+1
8.33E+2
7.48E+1
1.50E+0
3 .63E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .95E-2
2 .89E-2
2 .78E-2
1.91E-1
1.10E-1
1.40E-1
7.32E+0
6 .63E+0
5.37E+0
1.31E+2
3 .19E+4
8.49E-2
1.46E+2
3 .20E+4
5.00 ||
100
3 .01E-1
1.48E+2
1.04E-1
2 .57E-1
9.21E+0
1.19E+1
1.45E+0
2 .19E-2
1.02E+0
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .18E-3
2 .16E-3
2 .11E-3
2 .66E-2
2 .62E-2
2 .53E-2
6 .34E-4
5.98E-4
5.33E-4
7.84E-2
7.78E-2
7.66E-2
6 .17E+0
4 .73E+2
2 .65E-2
3 .63E+0
4 .77E+2
1, 000
3 .29E-1
1.44E+3
1.16E-1
1.46E+0
l.OOE+1
8.04E+1
9.97E+0
1.91E-1
3 .13E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .94E-2
2 .89E-2
2 .78E-2
4 .90E-3
3 .48E-3
1.99E-3
7.79E-1
7.66E-1
7.38E-1
5.45E+1
3 .67E+3
8.24E-2
1.89E+1
3 .69E + 3
1
10,000
1
1
3 .29E-1
1.19E+4
1.16E-1
7.07E+0
l.OOE+1
8.33E+2
6 .58E+1
1.19E+0
3 .57E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .31E-3
2 .28E-3
2 .22E-3
2 .94E-2
2 .89E-2
2 .78E-2
8.07E-2
4 .66E-2
5.92E-2
7.30E+0
6 .60E + 0
5.35E+0
1.31E+2
3 .18E+4
8.49E-2
1.44E+2
3 .20E+4
-------
Table 6 Continued
REASONABLE SCENARIO: Site Specific Population and Agriculture - With Radon.- 07-21-95 5:22p
30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
POTENTIAL CANCER DEATHS AVERTED--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
i
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVIB
XVIC
XVI I IA
XVI I IB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
DOE
DOD
NRC
llTotal
1
10. 00
100
2 .73E-1
1.48E+2
6 .92E-2
2 .45E-1
8.70E+0
1.18E+1
9.80E-1
1.60E-2
1.01E+0
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .17E-3
2 .15E-3
2 .10E-3
2 .65E-2
2 .62E-2
2 .53E-2
5.35E-4
5.05E-4
4 .50E-4
7.77E-2
7.71E-2
7.59E-2
6 .11E+0
4 .70E+2
2 .65E-2
3 .60E+0
4 .74E+2
1
1, 000
2 .99E-1
1.44E+3
7.69E-2
1.39E+0
9.47E+0
8.02E+1
6 .74E+0
1.39E-1
2 .95E+0
8.24E-2
.OOE+0
.OOE+0
.OOE+0
2 .30E-3
2 .27E-3
2 .21E-3
2 .94E-2
2 .88E-2
2 .77E-2
4 .14E-3
2 .94E-3
1.68E-3
7.71E-1
7.59E-1
7.32E-1
5.39E+1
3 .65E+3
8.24E-2
1.87E+1
3 .67E+3
10, 000
2 .99E-1
1.19E+4
7.69E-2
6 .75E+0
9.47E+0
8.32E+2
4 .45E+1
8.65E-1
3 .36E+0
8.49E-2
.OOE+0
.OOE+0
.OOE+0
2 .30E-3
2 .27E-3
2 .21E-3
2 .94E-2
2 .88E-2
2 .77E-2
6 .82E-2
3 .93E-2
5.00E-2
7.23E+0
6 .54E+0
5.30E+0
1.29E+2
3 .17E+4
8.49E-2
1.43E+2
3 .18E+4
15.00
100
2 .56E-1
1.48E+2
4 .29E-2
2 .34E-1
8.18E+0
1.18E+1
6 .94E-1
1.15E-2
1. OOE+0
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .16E-3
2 .14E-3
2 .10E-3
2 .64E-2
2 .61E-2
2 .52E-2
4 .92E-4
4 .64E-4
4 .14E-4
7.70E-2
7.64E-2
7.52E-2
5.99E+0
4 .67E+2
2 .65E-2
3 .58E+0
4 .71E+2
1, 000
2 .80E-1
1.44E+3
4 .77E-2
1.33E+0
8.90E+0
8.00E+1
4 .80E+0
l.OOE-1
2 .77E+0
8.23E-2
.OOE+0
.OOE+0
.OOE+0
2 .29E-3
2 .26E-3
2 .20E-3
2 .93E-2
2 .87E-2
2 .76E-2
3 .80E-3
2 .70E-3
1.55E-3
7.64E-1
7.52E-1
7.25E-1
5.33E+1
3 .64E+3
8.23E-2
1.85E+1
3 .66E+3
10, 000
2 .80E-1
1.18E+4
4 .77E-2
6 .43E+0
8.90E+0
8.30E+2
3 .16E+1
6 .24E-1
3 .14E+0
8.48E-2
.OOE+0
.OOE+0
.OOE+0
2 .29E-3
2 .26E-3
2 .20E-3
2 .93E-2
2 .87E-2
2 .76E-2
6 .26E-2
3 .61E-2
4 .60E-2
7.16E+0
6 .48E+0
5.25E+0
1.28E+2
3 .16E+4
8.48E-2
1.41E+2
3 .18E+4
25. 00
100
2 .28E-1
1.48E+2
2 .06E-2
2 .10E-1
7.38E+0
1.16E+1
4 .58E-1
7.88E-3
9.87E-1
2 .65E-2
.OOE+0
.OOE+0
.OOE+0
2 .15E-3
2 .13E-3
2 .09E-3
2 .62E-2
2 .58E-2
2 .50E-2
4 .33E-4
4 .09E-4
3 .65E-4
7.56E-2
7.50E-2
7.38E-2
5.78E+0
4 .62E+2
2 .65E-2
3 .53E+0
4 .66E+2
1, 000
2 .49E-1
1.44E+3
2 .29E-2
1.20E+0
8.03E+0
7.95E+1
3 .19E+0
6 .86E-2
2 .44E+0
8.22E-2
.OOE+0
.OOE+0
.OOE+0
2 .28E-3
2 .25E-3
2 .19E-3
2 .90E-2
2 .85E-2
2 .74E-2
3 .35E-3
2 .38E-3
1.36E-3
7.50E-1
7.38E-1
7.11E-1
5.16E+1
3 .62E+3
8.22E-2
1.82E+1
3 .64E+3
10, 000
2 .49E-1
1.18E+4
2 .29E-2
5.78E+0
8.03E+0
8.26E+2
2 .10E+1
4 .27E-1
2 .75E+0
8.46E-2
.OOE+0
.OOE+0
.OOE+0
2 .28E-3
2 .25E-3
2 .19E-3
2 .90E-2
2 .85E-2
2 .74E-2
5.52E-2
3 .19E-2
4 .05E-2
7.03E+0
6 .36E+0
5.15E+0
1.24E+2
3 .14E+4
8.46E-2
1.39E+2
3 .16E+4
75.00
100
1.33E-1
1.47E+2
.OOE+0
9.33E-2
6 .03E+0
1.11E+1
2 .59E-2
1.43E-3
9.16E-1
2 .63E-2
.OOE+0
.OOE+0
.OOE+0
2 .07E-3
2 .05E-3
2 .01E-3
2 .50E-2
2 .47E-2
2 .38E-2
3 .OOE-4
2 .83E-4
2 .52E-4
6 .35E-2
6 .30E-2
6 .20E-2
5.54E+0
4 .45E+2
2 .63E-2
3 .19E+0
4 .48E+2
1, 000
1.45E-1
1.43E+3
.OOE+0
5.30E-1
6 .57E+0
7.71E+1
1.56E-1
1.24E-2
1.78E+0
8.16E-2
.OOE+0
.OOE+0
.OOE+0
2 .20E-3
2 .17E-3
2 .11E-3
2 .77E-2
2 .72E-2
2 .61E-2
2 .32E-3
1.65E-3
9.44E-4
6 .30E-1
6 .20E-1
5.98E-1
4 .93E+1
3 .53E+3
8.16E-2
1.55E+1
3 .54E+3
10, 000
1.45E-1
1.16E+4
.OOE+0
2 .57E+0
6 .57E+0
8.02E+2
1. OOE+0
7.75E-2
1.96E+0
8.40E-2
.OOE+0
.OOE+0
.OOE+0
2 .20E-3
2 .17E-3
2 .11E-3
2 .77E-2
2 .72E-2
2 .61E-2
3 .83E-2
2 .21E-2
2 .81E-2
5.91E+0
5.35E+0
4 .33E+0
1.18E+2
3 .06E+4
8.40E-2
1.17E+2
3 .08E+4
100.00 ||
100
1.13E-1
1.46E+2
.OOE+0
3 .48E-2
5.36E+0
1.09E+1
.OOE+0
.OOE+0
8.87E-1
2 .62E-2
.OOE+0
.OOE+0
.OOE+0
2 .03E-3
2 .01E-3
1.96E-3
2 .45E-2
2 .41E-2
2 .33E-2
2 .53E-4
2 .39E-4
2 .13E-4
5.91E-2
5.86E-2
5.77E-2
4 .98E+0
4 .35E+2
2 .62E-2
3 .05E+0
4 .38E+2
1, 000
1.24E-1
1.42E+3
.OOE+0
1.98E-1
5.83E+0
7.62E+1
.OOE+0
.OOE+0
1.61E+0
8.14E-2
.OOE+0
.OOE+0
.OOE+0
2 .15E-3
2 .13E-3
2 .07E-3
2 .71E-2
2 .66E-2
2 .55E-2
1.96E-3
1.39E-3
7.98E-4
5.87E-1
5.77E-1
5.56E-1
4 .84E+1
3 .49E+3
8.14E-2
1.46E+1
3 .51E+3
1
10,000
1
1
1.24E-1
1.15E+4
.OOE+0
9.56E-1
5.83E+0
7.94E+2
.OOE+0
.OOE+0
1.76E+0
8.38E-2
.OOE+0
.OOE+0
.OOE+0
2 .15E-3
2 .13E-3
2 .07E-3
2 .71E-2
2 .66E-2
2 .55E-2
3 .23E-2
1.87E-2
2 .37E-2
5.50E+0
4 .97E+0
4 .03E+0
1.16E+2
3 .03E+4
8.38E-2
1.09E+2
3 .04E+4
-------
Table 7
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
|| I
II-l
II-2
II-3
II-4
II-5
1
Nluclide -
Cs-137
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
1
.10
100
8.13E-2
8.97E-3
6 .89E-3
.OOE+0
.OOE+0
6 .35E-3
.OOE+0
7.07E-3
9.19E-4
1.14E-2
5.69E-3
.OOE+0
3 .02E-2
.OOE+0
3 .53E-2
.OOE+0
5.82E-3
3 .14E-3
2 .25E-3
1.04E-2
6 .98E-4
1.03E-2
1.54E-3
1.30E-2
2 .19E-3
2 .49E-3
1.55E-2
.OOE+0
8.24E-3
1.04E-3
1.46E-4
.OOE+0
4 .40E-3
.OOE+0
.OOE+0
1.87E-4
1
1, 000
8 .13E-2
8 .63E-3
6 .63E-3
.OOE+0
.OOE+0
6 .10E-3
.OOE+0
6 .80E-3
8 .35E-4
1 .09E-2
5 .34E-3
.OOE+0
2 .88E-2
.OOE+0
3 .36E-2
.OOE+0
5 .65E-3
3 .05E-3
2 .16E-3
1 .01E-2
6 .70E-4
9 .97E-3
1 .46E-3
1 .23E-2
2 .02E-3
2 .30E-3
1 .47E-2
.OOE+0
7 .82E-3
1 .04E-3
1 .45E-4
.OOE+0
4 .40E-3
.OOE+0
.OOE+0
1 .86E-4
10, 000
8.13E-2
8.63E-3
6 .63E-3
.OOE+0
.OOE+0
6 .10E-3
.OOE+0
6 .80E-3
8.35E-4
1.09E-2
5.34E-3
.OOE+0
2 .88E-2
.OOE+0
3 .36E-2
.OOE+0
5.65E-3
3 .05E-3
2 .16E-3
1.01E-2
6 .70E-4
9.97E-3
1.46E-3
1.23E-2
2 .02E-3
2 .30E-3
1.47E-2
.OOE+0
7.82E-3
1.04E-3
1.45E-4
.OOE+0
4 .40E-3
.OOE+0
.OOE+0
1.86E-4
.50
100
4 .07E-1
3 .80E-2
2 .92E-2
2 .65E-3
1 .44E-3
2 .68E-2
2 .44E-4
2 .99E-2
4 .01E-3
3 .12E-2
1 .87E-2
8 .18E-3
1 .63E-1
1 .58E-3
4 .26E-1
2 .56E-3
2 .51E-2
1 .35E-2
1 .26E-2
4 .48E-2
3 .91E-3
4 .43E-2
5 .78E-3
8 .81E-2
1 .13E-2
1 .28E-2
5 .82E-2
.OOE+0
3 .09E-2
2 .03E-2
4 .24E-3
3 .98E-4
1 .28E-2
.OOE+0
1 .11E-4
5 .43E-3
1
1, 000
4 .07E-1
3 .69E-2
2 .84E-2
2 .51E-3
1.32E-3
2 .61E-2
1.95E-4
2 .91E-2
3 .93E-3
3 .06E-2
1.83E-2
7.86E-3
1.30E-1
1.38E-3
3 .92E-1
2 .47E-3
2 .44E-2
1.32E-2
1.22E-2
4 .36E-2
3 .80E-3
4 .30E-2
5.70E-3
4 .80E-2
1.11E-2
1.26E-2
5.74E-2
.OOE+0
3 .05E-2
2 .02E-2
4 .22E-3
3 .58E-4
1.27E-2
.OOE+0
1.09E-4
5.40E-3
10, 000
4 .07E-1
3 .69E-2
2 .84E-2
2 .51E-3
1 .32E-3
2 .61E-2
1 .95E-4
2 .91E-2
3 .93E-3
3 .06E-2
1 .83E-2
7 .86E-3
1 .30E-1
1 .38E-3
3 .92E-1
2 .47E-3
2 .44E-2
1 .32E-2
1 .22E-2
4 .36E-2
3 .80E-3
4 .30E-2
5 .70E-3
4 .80E-2
1 .11E-2
1 .26E-2
5 .74E-2
.OOE+0
3 .05E-2
2 .02E-2
4 .22E-3
3 .58E-4
1 .27E-2
.OOE+0
1 .09E-4
5 .40E-3
1.00
100
8.13E-1
7.05E-2
5.42E-2
7.21E-3
5.30E-3
4 .99E-2
1.78E-3
5.56E-2
6 .25E-3
4 .55E-2
2 .81E-2
1.66E-2
9.77E-1
5.60E-2
1.40E+0
4 .94E-3
4 .27E-2
2 .31E-2
2 .21E-2
7.64E-2
2 .56E-1
7.55E-2
5.89E-3
9.93E-1
1.15E-2
1.31E-2
5.94E-2
3 .40E-5
3 .15E-2
4 .14E-2
8.70E-3
8.51E-3
2 .19E-2
.OOE+0
4 .42E-4
1.12E-2
1, 000
8 .13E-1
6 .85E-2
5 .26E-2
6 .93E-3
5 .06E-3
4 .85E-2
1 .68E-3
5 .40E-2
6 .14E-3
4 .48E-2
2 .76E-2
1 .62E-2
9 .24E-1
5 .19E-2
1 .35E+0
4 .85E-3
4 .20E-2
2 .27E-2
2 .17E-2
7 .52E-2
2 .37E-1
7 .42E-2
5 .83E-3
4 .85E-1
1 .14E-2
1 .30E-2
5 .87E-2
5 .69E-6
3 .12E-2
4 .12E-2
8 .66E-3
8 .43E-3
2 .18E-2
.OOE+0
4 .39E-4
1 .11E-2
10, 000
8.13E-1
6 .85E-2
5.26E-2
6 .93E-3
5.06E-3
4 .85E-2
1.68E-3
5.40E-2
6 .14E-3
4 .48E-2
2 .76E-2
1.62E-2
9.24E-1
5.19E-2
1.35E+0
4 .85E-3
4 .20E-2
2 .27E-2
2 .17E-2
7.52E-2
2 .37E-1
7.42E-2
5.83E-3
4 .85E-1
1.14E-2
1.30E-2
5.87E-2
5.69E-6
3 .12E-2
4 .12E-2
8.66E-3
8.43E-3
2 .18E-2
.OOE+0
4 .39E-4
1.11E-2
3 .00
100
2 .44E + 0
9 .08E-2
3 .19E+0
1 .OOE-2
7 .70E-3
6 .42E-2
2 .73E-3
7 .16E-2
1 .15E-2
8 .36E-1
5 .02E-2
3 .64E-2
3 .81E+0
2 .59E-1
4 .80E+0
1 .67E-2
1 .18E+0
3 .19E-2
3 .10E-2
2 .44E+0
1 .20E+0
2 .15E+0
6 .36E-3
4 .59E+0
1 .25E-2
1 .43E-2
2 .44E-1
2 .34E-4
3 .40E-2
1 .53E-1
1 .25E-2
1 .54E-2
2 .96E-2
.OOE+0
7 .23E-4
1 .60E-2
1, 000
2 .44E+0
9.04E-2
1.54E+0
1. OOE-2
7.65E-3
6 .40E-2
2 .72E-3
7.13E-2
1.15E-2
4 .09E-1
5.01E-2
3 .64E-2
3 .81E + 0
2 .58E-1
4 .79E + 0
6 .88E-3
8.87E-1
3 .08E-2
2 .99E-2
1.86E+0
1.02E+0
1.61E+0
6 .05E-3
2 .25E + 0
1.19E-2
1.35E-2
1.06E-1
1.02E-4
3 .24E-2
1.53E-1
1.25E-2
1.54E-2
2 .96E-2
.OOE+0
7.23E-4
1.60E-2
10, 000
2 .44E+0
9 .04E-2
1 .54E+0
1 .OOE-2
7 .65E-3
6 .40E-2
2 .72E-3
7 .13E-2
1 .15E-2
4 .09E-1
5 .01E-2
3 .64E-2
3 .81E+0
2 .58E-1
4 .79E+0
6 .88E-3
8 .87E-1
3 .08E-2
2 .99E-2
1 .86E+0
1 .02E+0
1 .61E+0
6 .05E-3
2 .25E+0
1 .19E-2
1 .35E-2
1 .06E-1
1 .02E-4
3 .24E-2
1 .53E-1
1 .25E-2
1 .54E-2
2 .96E-2
.OOE+0
7 .23E-4
1 .60E-2
5.00 ||
100
4 .06E + 0
9.16E-2
6 .87E+0
1.02E-2
7.79E-3
6 .48E-2
2 .77E-3
7.22E-2
1.16E-2
4 .44E + 0
5.04E-2
3 .66E-2
3 .85E+0
2 .61E-1
4 .84E + 0
9.07E-2
2 .04E+0
3 .47E-2
3 .37E-2
4 .26E+0
1.74E+0
3 .87E+0
6 .86E-3
8.17E+0
1.44E-2
1.55E-2
4 .67E-1
4 .48E-4
3 .67E-2
3 .35E-1
1.26E-2
1.56E-2
2 .99E-2
.OOE+0
7.31E-4
1.61E-2
1, 000
4 .06E+0
9 .08E-2
3 .32E+0
1 .01E-2
7 .70E-3
6 .43E-2
2 .73E-3
7 .16E-2
1 .15E-2
2 .17E+0
5 .02E-2
3 .65E-2
3 .82E+0
2 .60E-1
4 .81E+0
5 .71E-2
1 .63E+0
3 .34E-2
3 .25E-2
3 .36E+0
1 .49E+0
3 .01E+0
6 .28E-3
4 .01E+0
1 .24E-2
1 .41E-2
2 .08E-1
2 .OOE-4
3 .36E-2
3 .35E-1
1 .26E-2
1 .56E-2
2 .99E-2
.OOE+0
7 .31E-4
1 .61E-2
1 1
10, ooo||
i
4 .06E + 0
9.08E-2
3 .32E+0
1.01E-2
7.70E-3
6 .43E-2
2 .73E-3
7.16E-2
1.15E-2
2 .17E+0
5.02E-2
3 .65E-2
3 .82E+0
2 .60E-1
4 .81E + 0
5.71E-2
1.63E+0
3 .34E-2
3 .25E-2
3 .36E + 0
1.49E+0
3 .01E + 0
6 .28E-3
4 .01E + 0
1.24E-2
1.41E-2
2 .08E-1
2 .OOE-4
3 .36E-2
3 .35E-1
1.26E-2
1.56E-2
2 .99E-2
.OOE+0
7.31E-4
1.61E-2
-------
Table 7 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
II-6
II-7
|| III
IV
||v
VI
VII
IX
X
XII
XIIIA
XIIIB
1
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
1
.10
100
.OOE+0
1.72E-2
.OOE+0
2 .28E-3
2 .11E-2
.OOE+0
2 .86E-2
1.14E+0
5.36E-2
1.14E+0
8.13E-2
6 .20E-1
2 .91E-2
6 .20E-1
8.13E-2
8.12E-2
1.09E-4
5.11E-6
1.09E-4
2 .OOE+0
3 .30E-1
.OOE+0
8.99E-1
1.50E-1
1.14E-1
1.81E-1
1.81E-1
2 .25E-1
3 .75E-2
1.20E+0
1.92E-2
1.13E-1
1.20E+0
1.92E-2
1.13E-1
1
1, 000
.OOE+0
1 .61E-2
.OOE+0
2 .OOE-3
1 .98E-2
.OOE+0
2 .69E-2
1 .14E+0
5 .36E-2
1 .14E+0
8 .13E-2
6 .20E-1
2 .91E-2
6 .20E-1
8 .13E-2
8 .12E-2
1 .09E-4
5 .11E-6
1 .09E-4
2 .OOE+0
3 .30E-1
.OOE+0
8 .99E-1
1 .50E-1
7 .28E-2
9 .96E-3
9 .96E-3
2 .25E-1
3 .75E-2
1 .20E+0
1 .92E-2
1 .13E-1
1 .20E+0
1 .92E-2
1 .13E-1
10, 000
.OOE+0
1.61E-2
.OOE+0
2 .OOE-3
1.98E-2
.OOE+0
2 .69E-2
1.14E+0
5.36E-2
1.14E+0
8.13E-2
6 .20E-1
2 .91E-2
6 .20E-1
8.13E-2
8.12E-2
1.09E-4
5.11E-6
1.09E-4
2 .OOE+0
3 .30E-1
.OOE+0
8.99E-1
1.50E-1
7.28E-2
9.96E-3
9.96E-3
2 .25E-1
3 .75E-2
1.20E+0
1.92E-2
1.13E-1
1.20E+0
1.92E-2
1.13E-1
.50
100
2 .12E-2
3 .13E-2
6 .41E-3
6 .OOE-3
3 .81E-2
.OOE+0
5 .15E-2
5 .70E+0
2 .68E-1
5 .70E+0
4 .07E-1
3 .09E+0
1 .45E-1
3 .09E+0
4 .07E-1
4 .06E-1
4 .93E-3
2 .32E-4
4 .93E-3
3 .73E+0
6 .23E-1
.OOE+0
4 .49E+0
7 .49E-1
5 .01E-1
1 .07E+0
1 .07E+0
1 .13E+0
1 .88E-1
6 .OOE+0
9 .70E-2
5 .62E-1
6 .OOE+0
9 .70E-2
5 .62E-1
1
1, 000
2 .02E-2
3 .07E-2
6 .07E-3
5.84E-3
3 .73E-2
.OOE+0
5.05E-2
5.70E+0
2 .68E-1
5.70E+0
4 .07E-1
3 .09E+0
1.45E-1
3 .09E+0
4 .07E-1
4 .06E-1
4 .93E-3
2 .32E-4
4 .93E-3
3 .73E+0
6 .23E-1
.OOE+0
4 .49E+0
7.49E-1
8.59E-2
7.25E-2
7.25E-2
1.13E+0
1.88E-1
6 .OOE+0
9.70E-2
5.62E-1
6 .OOE+0
9.70E-2
5.62E-1
10, 000
2 .02E-2
3 .07E-2
6 .07E-3
5 .84E-3
3 .73E-2
.OOE+0
5 .05E-2
5 .70E+0
2 .68E-1
5 .70E+0
4 .07E-1
3 .09E+0
1 .45E-1
3 .09E+0
4 .07E-1
4 .06E-1
4 .93E-3
2 .32E-4
4 .93E-3
3 .73E+0
6 .23E-1
.OOE+0
4 .49E+0
7 .49E-1
8 .59E-2
7 .25E-2
7 .25E-2
1 .13E+0
1 .88E-1
6 .OOE+0
9 .70E-2
5 .62E-1
6 .OOE+0
9 .70E-2
5 .62E-1
1.00
100
4 .49E-2
4 .71E-2
1.52E-2
1.02E-2
5.70E-2
.OOE+0
3 .60E-1
1.14E+1
5.36E-1
1.14E+1
8.13E-1
6 .19E + 0
2 .91E-1
6 .19E + 0
8.13E-1
8.11E-1
2 .54E-2
1.19E-3
2 .54E-2
7.46E+0
1.26E+0
.OOE+0
8.99E+0
1.50E+0
1.09E+0
1.92E+0
1.92E+0
2 .25E + 0
3 .75E-1
1.20E+1
1.98E-1
1.12E+0
1.20E+1
1.98E-1
1.12E+0
1, 000
4 .37E-2
4 .63E-2
1 .48E-2
9 .96E-3
5 .61E-2
.OOE+0
3 .30E-1
1 .14E+1
5 .36E-1
1 .14E+1
8 .13E-1
6 .19E+0
2 .91E-1
6 .19E+0
8 .13E-1
8 .11E-1
2 .54E-2
1 .19E-3
2 .54E-2
7 .46E+0
1 .26E+0
.OOE+0
8 .99E+0
1 .50E+0
1 .06E-1
1 .50E-1
1 .50E-1
2 .25E+0
3 .75E-1
1 .20E+1
1 .98E-1
1 .12E+0
1 .20E+1
1 .98E-1
1 .12E+0
10, 000
4 .37E-2
4 .63E-2
1.48E-2
9.96E-3
5.61E-2
.OOE+0
3 .30E-1
1.14E+1
5.36E-1
1.14E+1
8.13E-1
6 .19E+0
2 .91E-1
6 .19E+0
8.13E-1
8.11E-1
2 .54E-2
1.19E-3
2 .54E-2
7.46E+0
1.26E+0
.OOE+0
8.99E+0
1.50E+0
1.06E-1
1.50E-1
1.50E-1
2 .25E + 0
3 .75E-1
1.20E+1
1.98E-1
1.12E+0
1.20E+1
1.98E-1
1.12E+0
3 .00
100
6 .79E-2
1 .15E+0
2 .38E-2
1 .42E-2
1 .14E+1
.OOE+0
1 .22E+0
1 .23E+1
5 .78E-1
1 .23E+1
2 .44E+0
1 .86E+1
8 .73E-1
1 .86E+1
2 .44E+0
2 .41E+0
3 .37E-1
1 .58E-2
3 .37E-1
2 .24E+1
3 .77E+0
.OOE+0
2 .70E+1
4 .50E+0
4 .18E+0
3 .77E+0
3 .77E+0
6 .75E+0
1 .12E+0
3 .60E+1
5 .84E-1
3 .37E+0
3 .60E+1
5 .84E-1
3 .37E+0
1, 000
6 .70E-2
6 .66E-1
2 .35E-2
1.41E-2
1.01E+1
.OOE+0
1.18E+0
1.23E+1
5.78E-1
1.23E+1
2 .44E+0
1.86E+1
8.73E-1
1.86E+1
2 .44E + 0
2 .41E+0
3 .37E-1
1.58E-2
3 .37E-1
2 .24E + 1
3 .77E + 0
.OOE+0
2 .70E + 1
4 .50E + 0
2 .38E-1
4 .58E-1
4 .58E-1
6 .75E+0
1.12E+0
3 .60E + 1
5.84E-1
3 .37E + 0
3 .60E + 1
5.84E-1
3 .37E + 0
10, 000
6 .70E-2
6 .66E-1
2 .35E-2
1 .41E-2
1 .01E+1
.OOE+0
1 .18E+0
1 .23E+1
5 .78E-1
1 .23E+1
2 .44E+0
1 .86E+1
8 .73E-1
1 .86E+1
2 .44E+0
2 .41E+0
3 .37E-1
1 .58E-2
3 .37E-1
2 .24E + 1
3 .77E+0
.OOE+0
2 .70E+1
4 .50E+0
2 .38E-1
4 .58E-1
4 .58E-1
6 .75E+0
1 .12E+0
3 .60E+1
5 .84E-1
3 .37E+0
3 .60E+1
5 .84E-1
3 .37E+0
5.00 ||
100
7.19E-2
3 .80E+0
2 .52E-2
1.49E-2
1.77E+1
.OOE+0
1.41E+0
1.23E+1
5.78E-1
1.23E+1
4 .07E+0
3 .10E + 1
1.45E+0
3 .10E + 1
4 .07E+0
3 .98E + 0
1.10E+0
5.19E-2
1.10E+0
3 .73E + 1
6 .25E+0
.OOE+0
4 .50E + 1
7.49E+0
7.47E+0
5.12E+0
5.12E+0
1.12E+1
1.87E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E + 1
6 .40E-1
3 .69E + 0
1, 000
6 .94E-2
2 .15E+0
2 .43E-2
1 .45E-2
1 .38E+1
.OOE+0
1 .29E+0
1 .23E+1
5 .78E-1
1 .23E+1
4 .07E+0
3 .10E+1
1 .45E+0
3 .10E+1
4 .07E+0
3 .98E+0
1 .10E+0
5 .19E-2
1 .10E+0
3 .73E+1
6 .25E+0
.OOE+0
4 .50E+1
7 .49E+0
3 .80E-1
7 .64E-1
7 .64E-1
1 .12E+1
1 .87E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1 1
10, ooo||
i
6 .94E-2
2 .15E+0
2 .43E-2
1.45E-2
1.38E+1
.OOE+0
1.29E+0
1.23E+1
5.78E-1
1.23E+1
4 .07E + 0
3 .10E + 1
1.45E+0
3 .10E + 1
4 .07E + 0
3 .98E + 0
1.10E+0
5.19E-2
1.10E+0
3 .73E+1
6 .25E + 0
.OOE+0
4 .50E + 1
7.49E+0
3 .80E-1
7.64E-1
7.64E-1
1.12E+1
1.87E+0
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E + 0
-------
Table 7 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
XIIIC
XVIA
XVI B
XVI C
XVI I IA
XVI I IB
XVI I 1C
XXA
XXB
XXC
||XXIA
||XXIB
||xxic
XXII
1
U-238
U-235
U-234
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Th-232
Th-232
Th-232
Ra-226
Th-232
U-234
U-235
U-238
1
.10
100
1.20E+0
1.92E-2
1.13E-1
1.07E-2
.OOE+0
1.07E-2
.OOE+0
1.07E-2
.OOE+0
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
8.30E-1
2 .79E-2
1.42E-1
8.30E-1
2 .79E-2
1.42E-1
8.30E-1
2 .79E-2
1.42E-1
7.28E-3
7.28E-3
7.28E-3
1.24E-3
6 .09E-3
6 .84E-7
3 .22E-8
6 .84E-7
1
1, 000
1 .20E+0
1 .92E-2
1 .13E-1
1 .07E-2
.OOE+0
1 .07E-2
.OOE+0
1 .07E-2
.OOE+0
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
8 .30E-1
2 .79E-2
1 .42E-1
8 .30E-1
2 .79E-2
1 .42E-1
8 .30E-1
2 .79E-2
1 .42E-1
7 .28E-3
7 .28E-3
7 .28E-3
1 .24E-3
6 .09E-3
6 .85E-7
3 .22E-8
6 .85E-7
10, 000
1.20E+0
1.92E-2
1.13E-1
1.07E-2
.OOE+0
1.07E-2
.OOE+0
1.07E-2
.OOE+0
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
4 .05E-2
8.30E-1
2 .79E-2
1.42E-1
8.30E-1
2 .79E-2
1.42E-1
8.30E-1
2 .79E-2
1.42E-1
7.28E-3
7.28E-3
7.28E-3
1.24E-3
6 .09E-3
6 .85E-7
3 .22E-8
6 .85E-7
.50
100
6 .OOE+0
9 .70E-2
5 .62E-1
5 .36E-2
.OOE+0
5 .36E-2
.OOE+0
5 .36E-2
.OOE+0
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
3 .97E+0
1 .34E-1
6 .80E-1
3 .97E+0
1 .34E-1
6 .80E-1
3 .97E+0
1 .34E-1
6 .80E-1
3 .64E-2
3 .64E-2
3 .64E-2
6 .15E-3
3 .05E-2
9 .48E-5
4 .46E-6
9 .48E-5
1
1, 000
6 .OOE + 0
9.70E-2
5.62E-1
5.36E-2
.OOE+0
5.36E-2
.OOE+0
5.36E-2
.OOE+0
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
3 .97E + 0
1.34E-1
6 .80E-1
3 .97E+0
1.34E-1
6 .80E-1
3 .97E+0
1.34E-1
6 .80E-1
3 .64E-2
3 .64E-2
3 .64E-2
6 .15E-3
3 .04E-2
9.46E-5
4 .45E-6
9.46E-5
10, 000
6 .OOE+0
9 .70E-2
5 .62E-1
5 .36E-2
.OOE+0
5 .36E-2
.OOE+0
5 .36E-2
.OOE+0
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
2 .02E-1
3 .97E+0
1 .34E-1
6 .80E-1
3 .97E+0
1 .34E-1
6 .80E-1
3 .97E+0
1 .34E-1
6 .80E-1
3 .64E-2
3 .64E-2
3 .64E-2
6 .15E-3
3 .04E-2
9 .46E-5
4 .45E-6
9 .46E-5
1.00
100
1.20E+1
1.98E-1
1.12E+0
1.07E-1
.OOE+0
1.07E-1
.OOE+0
1.07E-1
.OOE+0
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
7.93E+0
2 .67E-1
1.36E+0
7.93E+0
2 .67E-1
1.36E+0
7.93E+0
2 .67E-1
1.36E+0
7.29E-2
7.29E-2
7.29E-2
1.23E-2
6 .09E-2
7.91E-4
3 .72E-5
7.91E-4
1, 000
1 .20E+1
1 .98E-1
1 .12E+0
1 .07E-1
.OOE+0
1 .07E-1
.OOE+0
1 .07E-1
.OOE+0
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
7 .93E+0
2 .67E-1
1 .36E+0
7 .93E+0
2 .67E-1
1 .36E+0
7 .93E+0
2 .67E-1
1 .36E+0
7 .29E-2
7 .29E-2
7 .29E-2
1 .22E-2
6 .07E-2
7 .83E-4
3 .68E-5
7 .83E-4
10, 000
1.20E+1
1.98E-1
1.12E+0
1.07E-1
.OOE+0
1.07E-1
.OOE+0
1.07E-1
.OOE+0
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
4 .05E-1
7.93E+0
2 .67E-1
1.36E+0
7.93E+0
2 .67E-1
1.36E+0
7.93E+0
2 .67E-1
1.36E+0
7.29E-2
7.29E-2
7.29E-2
1.22E-2
6 .07E-2
7.83E-4
3 .68E-5
7.83E-4
3 .00
100
3 .60E + 1
5 .84E-1
3 .37E+0
3 .22E-1
.OOE+0
3 .22E-1
.OOE+0
3 .22E-1
.OOE+0
1 .21E+0
1 .21E+0
1 .21E+0
1 .21E+0
1 .21E + 0
1 .21E + 0
2 .38E+1
8 .01E-1
4 .08E+0
2 .38E+1
8 .01E-1
4 .08E+0
2 .38E+1
8 .01E-1
4 .08E+0
2 .18E-1
2 .18E-1
2 .18E-1
3 .63E-2
1 .81E-1
2 .23E-2
1 .05E-3
2 .23E-2
1, 000
3 .60E + 1
5.84E-1
3 .37E + 0
3 .22E-1
.OOE+0
3 .22E-1
.OOE+0
3 .22E-1
.OOE+0
1.21E+0
1.21E+0
1.21E+0
1.21E+0
1.21E+0
1.21E+0
2 .38E + 1
8.01E-1
4 .08E+0
2 .38E + 1
8.01E-1
4 .08E + 0
2 .38E + 1
8.01E-1
4 .08E + 0
2 .18E-1
2 .18E-1
2 .18E-1
3 .53E-2
1.76E-1
2 .04E-2
9.61E-4
2 .04E-2
10, 000
3 .60E+1
5 .84E-1
3 .37E+0
3 .22E-1
.OOE+0
3 .22E-1
.OOE+0
3 .22E-1
.OOE+0
1 .21E+0
1 .21E+0
1 .21E+0
1 .21E+0
1 .21E+0
1 .21E + 0
2 .38E+1
8 .01E-1
4 .08E+0
2 .38E+1
8 .01E-1
4 .08E+0
2 .38E+1
8 .01E-1
4 .08E+0
2 .18E-1
2 .18E-1
2 .18E-1
3 .53E-2
1 .76E-1
2 .04E-2
9 .61E-4
2 .04E-2
5.00 ||
100
3 .94E+1
6 .40E-1
3 .69E+0
5.36E-1
.OOE+0
5.36E-1
.OOE+0
5.36E-1
.OOE+0
2 .02E+0
2 .02E + 0
2 .02E+0
2 .02E+0
2 .02E + 0
2 .02E + 0
3 .97E+1
1.34E+0
6 .80E+0
3 .97E + 1
1.34E+0
6 .80E + 0
3 .97E+1
1.34E+0
6 .80E + 0
3 .64E-1
3 .64E-1
3 .64E-1
5.94E-2
2 .96E-1
1.01E-1
4 .73E-3
1.01E-1
1, 000
3 .94E + 1
6 .40E-1
3 .69E + 0
5 .36E-1
.OOE+0
5 .36E-1
.OOE+0
5 .36E-1
.OOE+0
2 .02E+0
2 .02E+0
2 .02E + 0
2 .02E + 0
2 .02E+0
2 .02E + 0
3 .97E+1
1 .34E+0
6 .80E+0
3 .97E+1
1 .34E+0
6 .80E+0
3 .97E+1
1 .34E+0
6 .80E+0
3 .64E-1
3 .64E-1
3 .64E-1
5 .56E-2
2 .77E-1
8 .21E-2
3 .86E-3
8 .21E-2
1 1
10, ooo||
3 .94E + 1
6 .40E-1
3 .69E + 0
5.36E-l|
.OOE + o||
5.36E-l|
.OOE + o||
5.36E-l|
.OOE + o||
2 .02E+o|
2 .02E + o||
2 .02E+o|
2 .02E + o||
2 .02E+o|
2 .02E + o||
3 .97E + 1
1.34E+0
6 .80E + 0
3 .97E + 1
1.34E+0
6 .80E + 0
3 .97E + 1
1.34E+0
6 .80E + 0
3 .64E-l||
3 .64E-l||
3 .64E-l||
5.56E-2
2 .77E-1
8.21E-2
3 .86E-3
8.21E-2
-------
Table 7 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
|| I
II-l
II-2
II-3
II-4
II-5
1
Nluclide -
Cs-137
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
1
10 .00
100
8.13E+0
1.93E-1
1.41E+1
1.03E-2
7.93E-3
6 .56E-2
2 .83E-3
7.67E-2
1.17E-2
1.35E+1
5.09E-2
3 .71E-2
3 .93E+0
2 .66E-1
4 .95E+0
1.63E-1
3 .15E+0
3 .74E-2
3 .64E-2
6 .81E+0
2 .39E+0
6 .22E+0
7.88E-3
1.46E+1
1.16E-1
2 .45E-2
1.08E+0
8.84E-4
4 .21E-2
7.91E-1
1.28E-2
1.60E-2
3 .03E-2
.OOE+0
7.48E-4
1.64E-2
1
1, 000
8 .13E+0
9 .17E-2
7 .78E+0
1 .02E-2
7 .81E-3
6 .49E-2
2 .78E-3
7 .23E-2
1 .16E-2
6 .58E+0
5 .05E-2
3 .68E-2
3 .87E+0
2 .62E-1
4 .87E+0
1 .42E-1
2 .80E+0
3 .66E-2
3 .56E-2
5 .97E+0
2 .19E+0
5 .46E+0
6 .89E-3
8 .39E+0
1 .71E-2
1 .55E-2
4 .82E-1
4 .61E-4
3 .69E-2
7 .91E-1
1 .28E-2
1 .60E-2
3 .03E-2
.OOE+0
7 .48E-4
1 .64E-2
10, 000
8.13E+0
9.17E-2
7.78E+0
1.02E-2
7.81E-3
6 .49E-2
2 .78E-3
7.23E-2
1.16E-2
6 .58E + 0
5.05E-2
3 .68E-2
3 .87E + 0
2 .62E-1
4 .87E+0
1.42E-1
2 .80E+0
3 .66E-2
3 .56E-2
5.97E+0
2 .19E+0
5.46E+0
6 .89E-3
8.39E+0
1.71E-2
1.55E-2
4 .82E-1
4 .61E-4
3 .69E-2
7.91E-1
1.28E-2
1.60E-2
3 .03E-2
.OOE+0
7.48E-4
1.64E-2
15.00
100
1 .22E+1
6 .45E-1
1 .45E + 1
1 .03E-2
7 .94E-3
6 .57E-2
2 .83E-3
7 .81E-2
1 .18E-2
2 .25E+1
5 .15E-2
3 .76E-2
4 .02E+0
2 .71E-1
5 .05E+0
2 .13E-1
4 .18E+0
3 .93E-2
3 .83E-2
9 .19E+0
2 .91E+0
8 .44E+0
8 .62E-3
1 .89E+1
1 .88E-1
1 .15E-1
1 .61E+0
1 .20E-3
4 .61E-2
1 .25E+0
1 .31E-2
1 .65E-2
3 .08E-2
.OOE+0
7 .67E-4
1 .68E-2
1
1, 000
1.22E+1
9.25E-2
1.22E+1
1.03E-2
7.90E-3
6 .54E-2
2 .81E-3
7.29E-2
1.17E-2
1.10E+1
5.08E-2
3 .70E-2
3 .91E+0
2 .65E-1
4 .92E+0
1.91E-1
3 .71E + 0
3 .85E-2
3 .75E-2
8.10E+0
2 .68E+0
7.43E+0
7.48E-3
1.23E+1
7.58E-2
1.70E-2
8.41E-1
7.12E-4
4 .OOE-2
1.25E+0
1.31E-2
1.65E-2
3 .08E-2
.OOE+0
7.67E-4
1.68E-2
10, 000
1 .22E + 1
9 .25E-2
1 .22E+1
1 .03E-2
7 .90E-3
6 .54E-2
2 .81E-3
7 .29E-2
1 .17E-2
1 .10E+1
5 .08E-2
3 .70E-2
3 .91E+0
2 .65E-1
4 .92E+0
1 .91E-1
3 .71E+0
3 .85E-2
3 .75E-2
8 .10E+0
2 .68E+0
7 .43E+0
7 .48E-3
1 .23E+1
7 .58E-2
1 .70E-2
8 .41E-1
7 .12E-4
4 .OOE-2
1 .25E+0
1 .31E-2
1 .65E-2
3 .08E-2
.OOE+0
7 .67E-4
1 .68E-2
25.00
100
2 .03E+1
1.55E+0
1.54E+1
1.04E-2
7.96E-3
6 .58E-2
2 .84E-3
8.12E-2
1.20E-2
3 .55E+1
3 .95E-1
3 .83E-2
4 .14E+0
2 .78E-1
5.20E+0
2 .90E-1
6 .15E+0
4 .22E-2
4 .13E-2
1.54E+1
4 .11E+0
1.40E+1
1.01E-2
2 .72E+1
3 .31E-1
3 .04E-1
2 .91E+0
1.82E-3
5.38E-2
2 .16E+0
1.35E-2
1.73E-2
3 .18E-2
.OOE+0
8.02E-4
1.74E-2
1, 000
2 .03E+1
7 .81E-1
1 .47E+1
1 .03E-2
7 .94E-3
6 .57E-2
2 .83E-3
7 .85E-2
1 .18E-2
1 .99E+1
5 .13E-2
3 .75E-2
3 .99E+0
2 .70E-1
5 .02E+0
2 .68E-1
5 .55E+0
4 .14E-2
4 .04E-2
1 .34E+1
3 .61E+0
1 .21E+1
8 .52E-3
1 .84E+1
1 .79E-1
1 .03E-1
1 .54E+0
1 .16E-3
4 .56E-2
2 .16E+0
1 .35E-2
1 .73E-2
3 .18E-2
.OOE+0
8 .02E-4
1 .74E-2
10, 000
2 .03E+1
7.81E-1
1.47E+1
1.03E-2
7.94E-3
6 .57E-2
2 .83E-3
7.85E-2
1.18E-2
1.99E+1
5.13E-2
3 .75E-2
3 .99E+0
2 .70E-1
5.02E+0
2 .68E-1
5.55E+0
4 .14E-2
4 .04E-2
1.34E+1
3 .61E+0
1.21E+1
8.52E-3
1.84E+1
1.79E-1
1.03E-1
1.54E+0
1.16E-3
4 .56E-2
2 .16E+0
1.35E-2
1.73E-2
3 .18E-2
.OOE+0
8.02E-4
1.74E-2
75.00
100
6 .10E+1
6 .03E+0
2 .03E+1
1 .05E-2
8 .06E-3
6 .64E-2
2 .88E-3
1 .01E-1
1 .26E-2
7 .80E+1
3 .59E+0
4 .06E-2
4 .58E+0
3 .04E-1
5 .71E+0
4 .92E-1
1 .40E+1
4 .99E-2
4 .49E-1
4 .25E+1
1 .08E+1
4 .04E+1
3 .71E-1
5 .49E+1
1 .06E+0
1 .37E+0
1 .74E+1
1 .72E-1
3 .94E+0
6 .50E+0
1 .61E-2
2 .20E-2
1 .86E-1
.OOE+0
9 .93E-4
2 .07E-2
1, 000
6 .10E + 1
5.06E+0
1.89E+1
1.04E-2
8.03E-3
6 .62E-2
2 .86E-3
9.49E-2
1.22E-2
5.28E+1
1.59E+0
3 .92E-2
4 .30E + 0
2 .88E-1
5.39E+0
4 .73E-1
1.29E+1
4 .92E-2
3 .17E-1
3 .93E + 1
l.OOE+1
3 .73E + 1
1.62E-1
4 .30E + 1
6 .95E-1
8.15E-1
8.27E+0
3 .31E-2
1.09E+0
6 .50E + 0
1.61E-2
2 .20E-2
1.86E-1
.OOE+0
9.93E-4
2 .07E-2
10, 000
6 .10E+1
5 .06E+0
1 .89E+1
1 .04E-2
8 .03E-3
6 .62E-2
2 .86E-3
9 .49E-2
1 .22E-2
5 .28E + 1
1 .59E+0
3 .92E-2
4 .30E+0
2 .88E-1
5 .39E+0
4 .73E-1
1 .29E + 1
4 .92E-2
3 .17E-1
3 .93E+1
1 .OOE+1
3 .73E+1
1 .62E-1
4 .30E+1
6 .95E-1
8 .15E-1
8 .27E+0
3 .31E-2
1 .09E+0
6 .50E+0
1 .61E-2
2 .20E-2
1 .86E-1
.OOE+0
9 .93E-4
2 .07E-2
100.00 ||
100
8.13E+1
8.24E+0
2 .32E + 1
1.05E-2
8.12E-3
6 .67E-2
2 .90E-3
1.15E-1
1.29E-2
9.97E+1
5.16E+0
4 .18E-2
4 .82E+0
3 .19E-1
5.99E+0
5.47E-1
1.77E+1
1.05E-1
8.82E-1
5.27E+1
1.32E+1
5.06E+1
5.57E-1
6 .56E+1
1.41E+0
1.94E+0
3 .26E + 1
4 .15E-1
9.01E+0
8.59E+0
1.74E-2
6 .28E-2
2 .93E-1
.OOE+0
1.09E-3
2 .23E-2
1, 000
8 .13E+1
7 .11E+0
2 .19E+1
1 .05E-2
8 .09E-3
6 .66E-2
2 .89E-3
1 .08E-1
1 .24E-2
6 .69E+1
2 .66E+0
4 .OOE-2
4 .45E+0
2 .97E-1
5 .57E+0
5 .28E-1
1 .63E+1
5 .13E-2
7 .11E-1
4 .90E+1
1 .23E+1
4 .69E+1
3 .28E-1
5 .24E+1
9 .80E-1
1 .25E+0
1 .52E+1
1 .34E-1
3 .17E+0
8 .59E+0
1 .74E-2
6 .27E-2
2 .93E-1
.OOE+0
1 .09E-3
2 .23E-2
1 1
10, ooo||
i
8.13E+1
7.11E+0
2 .19E + 1
1.05E-2
8.09E-3
6 .66E-2
2 .89E-3
1.08E-1
1.24E-2
6 .69E+1
2 .66E+0
4 .OOE-2
4 .45E + 0
2 .97E-1
5.57E+0
5.28E-1
1.63E+1
5.13E-2
7.11E-1
4 .90E+1
1.23E+1
4 .69E + 1
3 .28E-1
5.24E+1
9.80E-1
1.25E+0
1.52E+1
1.34E-1
3 .17E + 0
8.59E+0
1.74E-2
6 .27E-2
2 .93E-1
.OOE+0
1.09E-3
2 .23E-2
-------
Table 7 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
II-6
II-7
|| III
IV
||v
VI
VII
IX
X
XII
XIIIA
XIIIB
1
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
1
10 .00
100
8.16E-2
9.61E+0
2 .89E-2
1.66E-2
3 .27E+1
.OOE+0
1.83E+0
1.23E+1
5.78E-1
1.23E+1
8.14E+0
6 .19E+1
2 .91E+0
6 .19E+1
8.13E+0
7.75E+0
5.34E+0
2 .51E-1
5.34E+0
6 .75E+1
1.14E+1
6 .80E-1
8.99E+1
1.50E+1
1.64E+1
6 .96E+0
6 .96E+0
2 .25E+1
3 .75E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1
1, 000
7 .52E-2
5 .79E+0
2 .65E-2
1 .55E-2
2 .30E+1
.OOE+0
1 .54E+0
1 .23E+1
5 .78E-1
1 .23E+1
8 .14E+0
6 .19E+1
2 .91E+0
6 .19E+1
8 .13E+0
7 .75E+0
5 .34E+0
2 .51E-1
5 .34E+0
6 .75E+1
1 .14E+1
6 .80E-1
8 .99E+1
1 .50E+1
7 .63E-1
1 .53E+0
1 .53E+0
2 .25E+1
3 .75E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
10, 000
7.52E-2
5.79E+0
2 .65E-2
1.55E-2
2 .30E+1
.OOE+0
1.54E+0
1.23E+1
5.78E-1
1.23E+1
8.14E+0
6 .19E+1
2 .91E + 0
6 .19E + 1
8.13E+0
7.75E+0
5.34E+0
2 .51E-1
5.34E+0
6 .75E + 1
1.14E+1
6 .80E-1
8.99E+1
1.50E+1
7.63E-1
1.53E+0
1.53E+0
2 .25E + 1
3 .75E + 0
3 .94E+1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E+0
15.00
100
8 .99E-2
1 .46E+1
1 .31E-1
1 .81E-2
4 .25E+1
.OOE+0
2 .27E+0
1 .23E+1
5 .78E-1
1 .23E+1
1 .22E+1
9 .29E+1
4 .36E+0
9 .29E+1
1 .22E+1
1 .13E+1
1 .30E+1
6 .11E-1
1 .30E+1
9 .77E+1
1 .66E+1
1 .34E+0
1 .35E+2
2 .25E+1
2 .57E+1
8 .OOE+0
8 .OOE+0
3 .37E+1
5 .62E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1
1, 000
8.09E-2
9.22E+0
2 .86E-2
1.65E-2
3 .20E+1
.OOE+0
1.80E+0
1.23E+1
5.78E-1
1.23E+1
1.22E+1
9.29E+1
4 .36E+0
9.29E+1
1.22E+1
1.13E+1
1.30E+1
6 .11E-1
1.30E+1
9.77E+1
1.66E+1
1.34E+0
1.35E+2
2 .25E+1
1.49E+0
2 .26E+0
2 .26E+0
3 .37E+1
5.62E+0
3 .94E+1
6 .40E-1
3 .69E + 0
3 .94E+1
6 .40E-1
3 .69E+0
10, 000
8 .09E-2
9 .22E+0
2 .86E-2
1 .65E-2
3 .20E+1
.OOE+0
1 .80E+0
1 .23E+1
5 .78E-1
1 .23E+1
1 .22E+1
9 .29E+1
4 .36E+0
9 .29E+1
1 .22E+1
1 .13E+1
1 .30E+1
6 .11E-1
1 .30E+1
9 .77E+1
1 .66E+1
1 .34E+0
1 .35E+2
2 .25E+1
1 .49E+0
2 .26E+0
2 .26E+0
3 .37E+1
5 .62E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
25.00
100
7.29E-1
1.71E+1
2 .73E-1
1.88E-2
4 .74E + 1
.OOE+0
2 .49E + 0
1.23E+1
5.78E-1
1.23E+1
2 .03E + 1
1.55E+2
7.27E+0
1.55E+2
2 .03E+1
1.83E+1
2 .89E+1
1.36E+0
2 .89E+1
1.56E+2
2 .59E+1
2 .95E+0
2 .25E+2
3 .75E+1
4 .46E + 1
9.29E+0
9.29E+0
5.62E+1
9.37E+0
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E+0
1, 000
9 .13E-2
1 .54E+1
1 .77E-1
1 .83E-2
4 .41E+1
.OOE+0
2 .34E+0
1 .23E+1
5 .78E-1
1 .23E+1
2 .03E+1
1 .55E+2
7 .27E+0
1 .55E+2
2 .03E+1
1 .83E+1
2 .89E+1
1 .36E+0
2 .89E+1
1 .56E+2
2 .59E+1
2 .95E+0
2 .25E+2
3 .75E+1
3 .97E+0
3 .65E+0
3 .65E+0
5 .62E+1
9 .37E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
10, 000
9.13E-2
1.54E+1
1.77E-1
1.83E-2
4 .41E+1
.OOE+0
2 .34E+0
1.23E+1
5.78E-1
1.23E+1
2 .03E+1
1.55E+2
7.27E+0
1.55E+2
2 .03E+1
1.83E+1
2 .89E + 1
1.36E+0
2 .89E+1
1.56E+2
2 .59E+1
2 .95E + 0
2 .25E+2
3 .75E+1
3 .97E+0
3 .65E+0
3 .65E+0
5.62E+1
9.37E+0
3 .94E+1
6 .40E-1
3 .69E + 0
3 .94E+1
6 .40E-1
3 .69E+0
75.00
100
5 .24E + 0
1 .89E+1
3 .72E-1
1 .93E-2
5 .08E+1
.OOE+0
2 .65E+0
1 .23E+1
5 .78E-1
1 .23E+1
6 .10E+1
4 .64E+2
2 .18E+1
4 .64E+2
6 .10E+1
5 .08E+1
1 .43E+2
6 .74E+0
1 .43E+2
4 .68E+2
7 .84E+1
8 .81E+0
6 .74E+2
1 .12E+2
1 .40E+2
1 .35E+1
1 .35E+1
1 .69E+2
2 .81E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1, 000
4 .28E+0
1.85E+1
3 .50E-1
1.92E-2
5.01E+1
.OOE+0
2 .61E+0
1.23E+1
5.78E-1
1.23E+1
6 .10E + 1
4 .64E + 2
2 .18E + 1
4 .64E + 2
6 .10E + 1
5.08E+1
1.43E+2
6 .74E + 0
1.43E+2
4 .68E + 2
7.84E+1
8.81E+0
6 .74E + 2
1.12E+2
3 .74E + 1
8.88E+0
8.88E+0
1.69E+2
2 .81E+1
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E + 0
10, 000
4 .28E+0
1 .85E+1
3 .50E-1
1 .92E-2
5 .01E+1
.OOE+0
2 .61E+0
1 .23E+1
5 .78E-1
1 .23E+1
6 .10E+1
4 .64E+2
2 .18E+1
4 .64E+2
6 .10E+1
5 .08E+1
1 .43E+2
6 .74E+0
1 .43E+2
4 .68E+2
7 .84E+1
8 .81E+0
6 .74E+2
1 .12E+2
3 .74E+1
8 .88E+0
8 .88E+0
1 .69E+2
2 .81E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E + 0
100.00 ||
100
7.52E+0
1.97E+1
4 .21E-1
1.96E-2
5.25E+1
.OOE+0
2 .73E+0
1.23E+1
5.78E-1
1.23E+1
8.13E+1
6 .19E + 2
2 .91E+1
6 .19E + 2
8.13E+1
6 .59E + 1
2 .16E + 2
1.01E+1
2 .16E + 2
6 .36E+2
1.06E+2
1.06E+1
8.99E+2
1.50E+2
1.88E+2
1.52E+1
1.52E+1
2 .25E + 2
3 .75E+1
3 .94E + 1
6 .40E-1
3 .69E+0
3 .94E + 1
6 .40E-1
3 .69E + 0
1, 000
6 .49E + 0
1 .94E+1
3 .98E-1
1 .95E-2
5 .17E+1
.OOE+0
2 .69E+0
1 .23E+1
5 .78E-1
1 .23E+1
8 .13E+1
6 .19E+2
2 .91E+1
6 .19E+2
8 .13E+1
6 .59E+1
2 .16E+2
1 .01E+1
2 .16E+2
6 .36E+2
1 .06E+2
1 .06E+1
8 .99E+2
1 .50E+2
6 .49E+1
1 .06E+1
1 .06E+1
2 .25E+2
3 .75E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1 1
10, ooo||
i
6 .49E + 0
1.94E+1
3 .98E-1
1.95E-2
5.17E+1
.OOE+0
2 .69E + 0
1.23E+1
5.78E-1
1.23E+1
8.13E+1
6 .19E+2
2 .91E+1
6 .19E+2
8.13E+1
6 .59E+1
2 .16E+2
1.01E+1
2 .16E + 2
6 .36E + 2
1.06E+2
1.06E+1
8.99E+2
1.50E+2
6 .49E+1
1.06E+1
1.06E+1
2 .25E+2
3 .75E+1
3 .94E+1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E + 0
-------
Table 7 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
XIIIC
XVIA
XVI B
XVI C
XVI I IA
XVI I IB
XVI I 1C
XXA
XXB
XXC
||XXIA
||XXIB
||xxic
XXII
1
U-238
U-235
U-234
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Th-232
Th-232
Th-232
Ra-226
Th-232
U-234
U-235
U-238
1
10 .00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
1.05E+0
8.46E-2
1.05E+0
8.46E-2
1.05E+0
8.46E-2
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
7.93E+1
2 .67E+0
1.36E+1
7.93E+1
2 .67E+0
1.36E+1
7.93E+1
2 .67E+0
1.36E+1
7.28E-1
7.28E-1
7.28E-1
1.10E-1
5.52E-1
6 .77E-1
3 .18E-2
6 .77E-1
1
1, 000
3 .94E+1
6 .40E-1
3 .69E+0
1 .05E+0
8 .46E-2
1 .05E+0
8 .46E-2
1 .05E+0
8 .46E-2
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
7 .93E+1
2 .67E+0
1 .36E+1
7 .93E+1
2 .67E+0
1 .36E+1
7 .93E+1
2 .67E+0
1 .36E+1
7 .28E-1
7 .28E-1
7 .28E-1
9 .39E-2
4 .70E-1
4 .13E-1
1 .94E-2
4 .13E-1
10, 000
3 .94E+1
6 .40E-1
3 .69E+0
1.05E+0
8.46E-2
1.05E+0
8.46E-2
1.05E+0
8.46E-2
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
4 .05E+0
7.93E+1
2 .67E+0
1.36E+1
7.93E+1
2 .67E+0
1.36E+1
7.93E+1
2 .67E+0
1.36E+1
7.28E-1
7.28E-1
7.28E-1
9.39E-2
4 .70E-1
4 .13E-1
1.94E-2
4 .13E-1
15.00
100
3 .94E+1
6 .40E-1
3 .69E + 0
1 .54E+0
2 .97E-1
1 .54E+0
2 .97E-1
1 .54E+0
2 .97E-1
6 .07E+0
6 .07E+0
6 .07E+0
6 .07E+0
6 .07E+0
6 .07E+0
1 .19E+2
4 .01E+0
2 .04E+1
1 .19E+2
4 .01E+0
2 .04E+1
1 .19E+2
4 .01E+0
2 .04E+1
1 .09E+0
1 .09E+0
1 .09E+0
1 .63E-1
8 .16E-1
1 .15E+0
5 .41E-2
1 .15E+0
1
1, 000
3 .94E+1
6 .40E-1
3 .69E + 0
1.54E+0
2 .97E-1
1.54E+0
2 .97E-1
1.54E+0
2 .97E-1
6 .07E + 0
6 .07E+0
6 .07E + 0
6 .07E+0
6 .07E + 0
6 .07E+0
1.19E+2
4 .01E + 0
2 .04E+1
1.19E+2
4 .01E+0
2 .04E+1
1.19E+2
4 .01E + 0
2 .04E+1
1.09E+0
1.09E+0
1.09E+0
1.21E-1
6 .07E-1
9.07E-1
4 .26E-2
9.07E-1
10, 000
3 .94E + 1
6 .40E-1
3 .69E + 0
1 .54E+0
2 .97E-1
1 .54E+0
2 .97E-1
1 .54E+0
2 .97E-1
6 .07E+0
6 .07E+0
6 .07E+0
6 .07E+0
6 .07E+0
6 .07E+0
1 .19E+2
4 .01E+0
2 .04E+1
1 .19E+2
4 .01E+0
2 .04E+1
1 .19E+2
4 .01E+0
2 .04E+1
1 .09E+0
1 .09E+0
1 .09E+0
1 .21E-1
6 .07E-1
9 .07E-1
4 .26E-2
9 .07E-1
25.00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
2 .54E + 0
5.99E-1
2 .54E+0
5.99E-1
2 .54E+0
5.99E-1
1.01E+1
1.01E+1
1.01E+1
1.01E+1
1.01E+1
1.01E+1
1.98E+2
6 .68E+0
3 .40E + 1
1.98E+2
6 .68E+0
3 .40E+1
1.98E+2
6 .68E+0
3 .40E+1
1.82E+0
1.82E+0
1.82E+0
2 .26E-1
1.46E+0
1.37E+0
6 .45E-2
1.37E+0
1, 000
3 .94E+1
6 .40E-1
3 .69E+0
2 .54E+0
5 .99E-1
2 .54E+0
5 .99E-1
2 .54E+0
5 .99E-1
1 .01E+1
1 .01E+1
1 .01E+1
1 .01E+1
1 .01E+1
1 .01E+1
1 .98E+2
6 .68E+0
3 .40E+1
1 .98E+2
6 .68E+0
3 .40E+1
1 .98E+2
6 .68E+0
3 .40E+1
1 .82E+0
1 .82E+0
1 .82E+0
2 .05E-1
1 .09E+0
1 .30E+0
6 .13E-2
1 .30E+0
10, 000
3 .94E+1
6 .40E-1
3 .69E+0
2 .54E+0
5.99E-1
2 .54E+0
5.99E-1
2 .54E+0
5.99E-1
1.01E+1
1.01E+1
1.01E+1
1.01E+1
1.01E+1
1.01E+1
1.98E+2
6 .68E + 0
3 .40E+1
1.98E+2
6 .68E + 0
3 .40E + 1
1.98E+2
6 .68E + 0
3 .40E + 1
1.82E+0
1.82E+0
1.82E+0
2 .05E-1
1.09E+0
1.30E+0
6 .13E-2
1.30E+0
75.00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
7 .74E+0
1 .28E+0
7 .74E+0
1 .28E+0
7 .74E+0
1 .28E+0
3 .04E+1
3 .04E+1
3 .04E+1
3 .04E+1
3 .04E+1
3 .04E+1
5 .95E+2
2 .OOE+1
1 .02E+2
5 .95E+2
2 .OOE+1
1 .02E+2
5 .95E+2
2 .OOE+1
1 .02E+2
5 .46E+0
5 .46E+0
5 .46E+0
9 .53E-1
4 .13E+0
4 .07E+0
1 .91E-1
4 .07E+0
1, 000
3 .94E + 1
6 .40E-1
3 .69E+0
7.74E+0
1.28E+0
7.74E+0
1.28E+0
7.74E+0
1.28E+0
3 .04E+1
3 .04E + 1
3 .04E+1
3 .04E+1
3 .04E + 1
3 .04E + 1
5.95E+2
2 .OOE + 1
1.02E+2
5.95E+2
2 .OOE + 1
1.02E+2
5.95E+2
2 .OOE + 1
1.02E+2
5.46E+0
5.46E+0
5.46E+0
7.65E-1
3 .61E + 0
2 .75E + 0
1.29E-1
2 .75E + 0
10, 000
3 .94E+1
6 .40E-1
3 .69E + 0
7 .74E+0
1 .28E+0
7 .74E+0
1 .28E+0
7 .74E+0
1 .28E+0
3 .04E+1
3 .04E+1
3 .04E+1
3 .04E+1
3 .04E + 1
3 .04E+1
5 .95E+2
2 .OOE+1
1 .02E+2
5 .95E+2
2 .OOE+1
1 .02E+2
5 .95E+2
2 .OOE+1
1 .02E+2
5 .46E+0
5 .46E+0
5 .46E+0
7 .65E-1
3 .61E+0
2 .75E+0
1 .29E-1
2 .75E+0
100.00 ||
100
3 .94E+1
6 .40E-1
3 .69E+0
1.03E+1
1.59E+0
1.03E+1
1.59E+0
1.03E+1
1.59E+0
4 .05E + 1
4 .05E+1
4 .05E+1
4 .05E + 1
4 .05E + 1
4 .05E+1
7.93E+2
2 .67E+1
1.36E+2
7.93E+2
2 .67E + 1
1.36E+2
7.93E+2
2 .67E + 1
1.36E+2
7.28E+0
7.28E+0
7.28E+0
1.05E+0
5.76E+0
4 .85E+0
2 .28E-1
4 .85E+0
1, 000
3 .94E + 1
6 .40E-1
3 .69E + 0
1 .03E+1
1 .59E+0
1 .03E+1
1 .59E+0
1 .03E+1
1 .59E+0
4 .05E+1
4 .05E+1
4 .05E+1
4 .05E+1
4 .05E+1
4 .05E+1
7 .93E+2
2 .67E+1
1 .36E+2
7 .93E+2
2 .67E+1
1 .36E+2
7 .93E+2
2 .67E+1
1 .36E+2
7 .28E+0
7 .28E+0
7 .28E+0
9 .86E-1
4 .59E+0
4 .30E+0
2 .02E-1
4 .30E+0
1 1
10, ooo||
3 .94E + 1
6 .40E-1
3 .69E + 0
1.03E+l|
1.59E + o||
1.03E+l|
1.59E + o||
1.03E+l|
1.59E + o||
4 .05E + l|
4 .05E + l||
4 .05E + l|
4 .05E + l||
4 .05E + l|
4 .05E + l||
7.93E+2
2 .67E + 1
1.36E+2
7.93E+2
2 .67E + 1
1.36E+2
7.93E+2
2 .67E + 1
1.36E+2
7.28E + o||
7.28E + o||
7.28E + o||
9.86E-1
4 .59E + 0
4 .30E + 0
2 .02E-1
4 .30E + 0
-------
Table 8
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects, included in population impacts
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
|| I
II-l
II-2
II-3
II-4
II-5
1
Nluclide -
Cs-137
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
1
.10
100
2 .27E-1
2 .78E-2
2 .13E-2
1.23E-3
2 .43E-4
1.97E-2
.OOE+0
2 .19E-2
2 .83E-3
2 .36E-2
1.37E-2
3 .70E-3
6 .25E-2
.OOE+0
7.30E-2
1.19E-3
1.49E-2
8.03E-3
7.14E-3
2 .66E-2
2 .21E-3
2 .63E-2
3 .73E-3
3 .15E-2
6 .89E-3
7.84E-3
3 .76E-2
.OOE+0
2 .OOE-2
1.11E-2
2 .28E-3
.OOE+0
8.77E-3
.OOE+0
.OOE+0
2 .93E-3
1
1, 000
2 .27E-1
2 .69E-2
2 .07E-2
1 .11E-3
1 .40E-4
1 .90E-2
.OOE+0
2 .12E-2
2 .72E-3
2 .29E-2
1 .33E-2
3 .32E-3
6 .08E-2
.OOE+0
7 .10E-2
1 .13E-3
1 .45E-2
7 .82E-3
6 .92E-3
2 .59E-2
2 .15E-3
2 .56E-2
3 .54E-3
2 .99E-2
6 .49E-3
7 .38E-3
3 .57E-2
.OOE+0
1 .90E-2
1 .11E-2
2 .27E-3
.OOE+0
8 .74E-3
.OOE+0
.OOE+0
2 .91E-3
10, 000
2 .27E-1
2 .69E-2
2 .07E-2
1.11E-3
1.40E-4
1.90E-2
.OOE+0
2 .12E-2
2 .72E-3
2 .29E-2
1.33E-2
3 .32E-3
6 .08E-2
.OOE+0
7.10E-2
1.13E-3
1.45E-2
7.82E-3
6 .92E-3
2 .59E-2
2 .15E-3
2 .56E-2
3 .54E-3
2 .99E-2
6 .49E-3
7.38E-3
3 .57E-2
.OOE+0
1.90E-2
1.11E-2
2 .27E-3
.OOE+0
8.74E-3
.OOE+0
.OOE+0
2 .91E-3
.50
100
1 .13E+0
9 .04E-2
7 .18E-1
9 .99E-3
7 .64E-3
6 .39E-2
2 .71E-3
7 .12E-2
8 .33E-3
5 .88E-2
3 .68E-2
2 .44E-2
1 .96E+0
1 .31E-1
2 .57E+0
5 .98E-3
1 .68E-1
2 .72E-2
2 .63E-2
5 .40E-1
5 .52E-1
4 .07E-1
6 .02E-3
1 .99E+0
1 .18E-2
1 .34E-2
8 .84E-2
8 .81E-5
3 .22E-2
5 .65E-2
1 .19E-2
1 .43E-2
2 .85E-2
.OOE+0
6 .80E-4
1 .53E-2
1
1, 000
1.13E+0
9.03E-2
3 .36E-1
9.98E-3
7.64E-3
6 .39E-2
2 .71E-3
7.12E-2
8.20E-3
5.79E-2
3 .63E-2
2 .40E-2
1.89E+0
1.26E-1
2 .49E + 0
5.90E-3
1.18E-1
2 .69E-2
2 .60E-2
4 .69E-1
5.21E-1
3 .28E-1
5.89E-3
9.42E-1
1.15E-2
1.31E-2
5.93E-2
3 .11E-5
3 .15E-2
5.64E-2
1.19E-2
1.43E-2
2 .84E-2
.OOE+0
6 .80E-4
1.52E-2
10, 000
1 .13E+0
9 .03E-2
3 .36E-1
9 .98E-3
7 .64E-3
6 .39E-2
2 .71E-3
7 .12E-2
8 .20E-3
5 .79E-2
3 .63E-2
2 .40E-2
1 .89E+0
1 .26E-1
2 .49E+0
5 .90E-3
1 .18E-1
2 .69E-2
2 .60E-2
4 .69E-1
5 .21E-1
3 .28E-1
5 .89E-3
9 .42E-1
1 .15E-2
1 .31E-2
5 .93E-2
3 .11E-5
3 .15E-2
5 .64E-2
1 .19E-2
1 .43E-2
2 .84E-2
.OOE+0
6 .80E-4
1 .52E-2
1.00
100
2 .27E + 0
9.09E-2
3 .64E + 0
1.01E-2
7.71E-3
6 .43E-2
2 .74E-3
7.17E-2
1.15E-2
9.79E-1
5.02E-2
3 .65E-2
3 .81E+0
2 .59E-1
4 .80E+0
1.77E-2
1.19E+0
3 .20E-2
3 .10E-2
2 .46E+0
1.21E+0
2 .17E+0
6 .40E-3
4 .85E+0
1.26E-2
1.43E-2
2 .62E-1
2 .50E-4
3 .42E-2
1.69E-1
1.25E-2
1.54E-2
2 .97E-2
.OOE+0
7.23E-4
1.60E-2
1, 000
2 .27E+0
9 .05E-2
1 .71E+0
1 .OOE-2
7 .66E-3
6 .40E-2
2 .72E-3
7 .13E-2
1 .15E-2
4 .64E-1
5 .01E-2
3 .64E-2
3 .81E+0
2 .59E-1
4 .79E+0
6 .87E-3
8 .81E-1
3 .08E-2
2 .98E-2
1 .85E+0
1 .01E+0
1 .60E+0
6 .06E-3
2 .30E+0
1 .19E-2
1 .35E-2
1 .09E-1
1 .05E-4
3 .24E-2
1 .69E-1
1 .25E-2
1 .54E-2
2 .96E-2
.OOE+0
7 .23E-4
1 .60E-2
10, 000
2 .27E+0
9.05E-2
1.71E+0
1. OOE-2
7.66E-3
6 .40E-2
2 .72E-3
7.13E-2
1.15E-2
4 .64E-1
5.01E-2
3 .64E-2
3 .81E+0
2 .59E-1
4 .79E+0
6 .87E-3
8.81E-1
3 .08E-2
2 .98E-2
1.85E+0
1.01E+0
1.60E+0
6 .06E-3
2 .30E+0
1.19E-2
1.35E-2
1.09E-1
1.05E-4
3 .24E-2
1.69E-1
1.25E-2
1.54E-2
2 .96E-2
.OOE+0
7.23E-4
1.60E-2
3 .00
100
6 .81E+0
1 .64E-1
1 .41E+1
1 .03E-2
7 .93E-3
6 .56E-2
2 .83E-3
7 .66E-2
1 .17E-2
1 .24E+1
5 .09E-2
3 .71E-2
3 .92E + 0
2 .66E-1
4 .94E+0
1 .52E-1
2 .96E+0
3 .70E-2
3 .60E-2
6 .35E+0
2 .29E+0
5 .81E+0
7 .78E-3
1 .40E+1
1 .06E-1
1 .77E-2
1 .01E+0
8 .40E-4
4 .16E-2
8 .09E-1
1 .28E-2
1 .60E-2
3 .04E-2
.OOE+0
7 .49E-4
1 .64E-2
1, 000
6 .81E+0
9.16E-2
7.19E+0
1.02E-2
7.79E-3
6 .48E-2
2 .77E-3
7.22E-2
1.16E-2
5.89E+0
5.05E-2
3 .67E-2
3 .86E + 0
2 .62E-1
4 .86E + 0
1.32E-1
2 .65E + 0
3 .62E-2
3 .53E-2
5.62E+0
2 .11E + 0
5.13E+0
6 .80E-3
7.72E+0
1.35E-2
1.53E-2
4 .36E-1
4 .21E-4
3 .64E-2
8.08E-1
1.28E-2
1.60E-2
3 .04E-2
.OOE+0
7.49E-4
1.64E-2
10, 000
6 .81E+0
9 .16E-2
7 .19E+0
1 .02E-2
7 .79E-3
6 .48E-2
2 .77E-3
7 .22E-2
1 .16E-2
5 .89E+0
5 .05E-2
3 .67E-2
3 .86E+0
2 .62E-1
4 .86E+0
1 .32E-1
2 .65E+0
3 .62E-2
3 .53E-2
5 .62E+0
2 .11E+0
5 .13E+0
6 .80E-3
7 .72E+0
1 .35E-2
1 .53E-2
4 .36E-1
4 .21E-4
3 .64E-2
8 .08E-1
1 .28E-2
1 .60E-2
3 .04E-2
.OOE+0
7 .49E-4
1 .64E-2
5.00 ||
100
1.13E+1
8.04E-1
1.47E+1
1.03E-2
7.94E-3
6 .57E-2
2 .83E-3
7.86E-2
1.18E-2
2 .39E+1
5.15E-2
3 .77E-2
4 .03E+0
2 .72E-1
5.07E+0
2 .12E-1
4 .15E + 0
3 .92E-2
3 .83E-2
9.13E+0
2 .90E+0
8.39E+0
8.68E-3
1.92E+1
1.94E-1
1.23E-1
1.66E+0
1.23E-3
4 .64E-2
1.45E+0
1.32E-2
1.66E-2
3 .11E-2
.OOE+0
7.74E-4
1.69E-2
1, 000
1 .13E+1
9 .26E-2
1 .27E+1
1 .03E-2
7 .90E-3
6 .55E-2
2 .81E-3
7 .30E-2
1 .17E-2
1 .13E+1
5 .08E-2
3 .70E-2
3 .91E+0
2 .65E-1
4 .92E+0
1 .91E-1
3 .71E+0
3 .84E-2
3 .75E-2
8 .08E+0
2 .68E+0
7 .41E+0
7 .52E-3
1 .26E+1
7 .99E-2
1 .71E-2
8 .63E-1
7 .30E-4
4 .02E-2
1 .45E+0
1 .32E-2
1 .66E-2
3 .11E-2
.OOE+0
7 .74E-4
1 .69E-2
1 1
10, ooo||
i
1.13E+1
9.26E-2
1.27E+1
1.03E-2
7.90E-3
6 .55E-2
2 .81E-3
7.30E-2
1.17E-2
1.13E+1
5.08E-2
3 .70E-2
3 .91E+0
2 .65E-1
4 .92E + 0
1.91E-1
3 .71E + 0
3 .84E-2
3 .75E-2
8.08E+0
2 .68E + 0
7.41E+0
7.52E-3
1.26E+1
7.99E-2
1.71E-2
8.63E-1
7.30E-4
4 .02E-2
1.45E+0
1.32E-2
1.66E-2
3 .11E-2
.OOE+0
7.74E-4
1.69E-2
-------
Table 8 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
II-6
II-7
|| III
IV
||v
VI
VII
IX
X
XII
XIIIA
XIIIB
1
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
1
.10
100
1.13E-2
2 .47E-2
2 .76E-3
4 .28E-3
3 .02E-2
.OOE+0
4 .09E-2
3 .44E+0
1.62E-1
3 .44E+0
2 .27E-1
1.91E+0
9.00E-2
1.91E+0
2 .27E-1
2 .27E-1
1.24E-3
5.82E-5
1.24E-3
2 .56E+0
4 .25E-1
.OOE+0
3 .06E+0
5.10E-1
8.20E-2
5.49E-2
5.49E-2
1.06E+0
1.77E-1
3 .11E+0
5.01E-2
2 .91E-1
3 .11E+0
5.01E-2
2 .91E-1
1
1, 000
1 .06E-2
2 .42E-2
2 .48E-3
4 .14E-3
2 .96E-2
.OOE+0
4 .OOE-2
3 .44E+0
1 .62E-1
3 .44E+0
2 .27E-1
1 .91E+0
9 .OOE-2
1 .91E+0
2 .27E-1
2 .27E-1
1 .24E-3
5 .82E-5
1 .24E-3
2 .56E+0
4 .25E-1
.OOE+0
3 .06E+0
5 .10E-1
7 .65E-2
2 .87E-2
2 .87E-2
1 .06E+0
1 .77E-1
3 .11E+0
5 .01E-2
2 .91E-1
3 .11E+0
5 .01E-2
2 .91E-1
10, 000
1.06E-2
2 .42E-2
2 .48E-3
4 .14E-3
2 .96E-2
.OOE+0
4 .OOE-2
3 .44E+0
1.62E-1
3 .44E+0
2 .27E-1
1.91E+0
9. OOE-2
1.91E+0
2 .27E-1
2 .27E-1
1.24E-3
5.82E-5
1.24E-3
2 .56E+0
4 .25E-1
.OOE+0
3 .06E+0
5.10E-1
7.64E-2
2 .82E-2
2 .82E-2
1.06E+0
1.77E-1
3 .11E+0
5.01E-2
2 .91E-1
3 .11E+0
5.01E-2
2 .91E-1
.50
100
6 .26E-2
5 .89E-2
2 .18E-2
1 .33E-2
2 .71E+0
.OOE+0
9 .99E-1
1 .23E+1
5 .78E-1
1 .23E+1
1 .13E+0
9 .58E+0
4 .50E-1
9 .58E+0
1 .13E+0
1 .13E+0
5 .57E-2
2 .62E-3
5 .57E-2
1 .28E+1
2 .16E+0
.OOE+0
1 .53E+1
2 .55E+0
1 .62E-1
3 .12E-1
3 .12E-1
5 .30E+0
8 .84E-1
1 .56E+1
2 .49E-1
1 .46E+0
1 .56E+1
2 .49E-1
1 .46E+0
1
1, 000
6 .23E-2
5.88E-2
2 .17E-2
1.32E-2
2 .24E+0
.OOE+0
9.87E-1
1.23E+1
5.78E-1
1.23E+1
1.13E+0
9.58E+0
4 .50E-1
9.58E+0
1.13E+0
1.13E+0
5.57E-2
2 .62E-3
5.57E-2
1.28E+1
2 .16E+0
.OOE+0
1.53E+1
2 .55E+0
1.10E-1
1.64E-1
1.64E-1
5.30E+0
8.84E-1
1.56E+1
2 .49E-1
1.46E+0
1.56E+1
2 .49E-1
1.46E+0
10, 000
6 .23E-2
5 .88E-2
2 .17E-2
1 .32E-2
2 .24E+0
.OOE+0
9 .87E-1
1 .23E+1
5 .78E-1
1 .23E+1
1 .13E+0
9 .58E+0
4 .50E-1
9 .58E+0
1 .13E+0
1 .13E+0
5 .57E-2
2 .62E-3
5 .57E-2
1 .28E+1
2 .16E+0
.OOE+0
1 .53E+1
2 .55E+0
1 .09E-1
1 .62E-1
1 .62E-1
5 .30E+0
8 .84E-1
1 .56E+1
2 .49E-1
1 .46E+0
1 .56E+1
2 .49E-1
1 .46E+0
1.00
100
6 .86E-2
1.61E+0
2 .40E-2
1.43E-2
1.25E+1
.OOE+0
1.25E+0
1.23E+1
5.78E-1
1.23E+1
2 .27E+0
1.92E+1
9.01E-1
1.92E+1
2 .27E+0
2 .25E+0
2 .84E-1
1.34E-2
2 .84E-1
2 .56E+1
4 .30E + 0
.OOE+0
3 .06E+1
5.10E+0
3 .34E-1
6 .22E-1
6 .22E-1
1.06E+1
1.77E+0
3 .11E + 1
5.04E-1
2 .91E + 0
3 .11E + 1
5.04E-1
2 .91E + 0
1, 000
6 .74E-2
8 .77E-1
2 .36E-2
1 .41E-2
1 .07E+1
.OOE+0
1 .20E+0
1 .23E+1
5 .78E-1
1 .23E+1
2 .27E+0
1 .92E+1
9 .01E-1
1 .92E+1
2 .27E+0
2 .25E+0
2 .84E-1
1 .34E-2
2 .84E-1
2 .56E+1
4 .30E+0
.OOE+0
3 .06E+1
5 .10E+0
1 .71E-1
3 .33E-1
3 .33E-1
1 .06E+1
1 .77E+0
3 .11E+1
5 .04E-1
2 .91E+0
3 .11E+1
5 .04E-1
2 .91E+0
10, 000
6 .74E-2
8.77E-1
2 .36E-2
1.41E-2
1.07E+1
.OOE+0
1.20E+0
1.23E+1
5.78E-1
1.23E+1
2 .27E+0
1.92E+1
9.01E-1
1.92E+1
2 .27E+0
2 .25E+0
2 .84E-1
1.34E-2
2 .84E-1
2 .56E+1
4 .30E + 0
.OOE+0
3 .06E + 1
5.10E+0
1.68E-1
3 .27E-1
3 .27E-1
1.06E+1
1.77E+0
3 .11E + 1
5.04E-1
2 .91E + 0
3 .11E + 1
5.04E-1
2 .91E + 0
3 .00
100
8 .14E-2
9 .50E+0
2 .88E-2
1 .66E-2
3 .25E+1
.OOE+0
1 .82E+0
1 .23E+1
5 .78E-1
1 .23E+1
6 .81E+0
5 .75E+1
2 .70E+0
5 .75E+1
6 .80E+0
6 .56E+0
3 .61E+0
1 .70E-1
3 .61E+0
6 .77E+1
1 .14E+1
6 .88E-1
9 .18E+1
1 .53E+1
1 .03E+0
1 .86E+0
1 .86E+0
3 .18E+1
5 .30E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1, 000
7.48E-2
5.53E+0
2 .63E-2
1.54E-2
2 .23E + 1
.OOE+0
1.52E+0
1.23E+1
5.78E-1
1.23E+1
6 .81E+0
5.75E+1
2 .70E+0
5.75E+1
6 .80E + 0
6 .56E+0
3 .61E + 0
1.70E-1
3 .61E + 0
6 .77E+1
1.14E+1
6 .88E-1
9.18E+1
1.53E+1
4 .72E-1
1. OOE + 0
1. OOE + 0
3 .18E + 1
5.30E+0
3 .94E+1
6 .40E-1
3 .69E + 0
3 .94E+1
6 .40E-1
3 .69E + 0
10, 000
7 .48E-2
5 .53E+0
2 .63E-2
1 .54E-2
2 .23E+1
.OOE+0
1 .52E+0
1 .23E+1
5 .78E-1
1 .23E+1
6 .81E+0
5 .75E+1
2 .70E+0
5 .75E+1
6 .80E+0
6 .56E+0
3 .61E+0
1 .70E-1
3 .61E+0
6 .77E+1
1 .14E+1
6 .88E-1
9 .18E+1
1 .53E+1
4 .65E-1
9 .85E-1
9 .85E-1
3 .18E+1
5 .30E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
5.00 ||
100
9.15E-2
1.55E+1
1.84E-1
1.84E-2
4 .43E + 1
.OOE+0
2 .35E + 0
1.23E+1
5.78E-1
1.23E+1
1.13E+1
9.58E+1
4 .50E + 0
9.58E+1
1.13E+1
1.06E+1
1.12E+1
5.28E-1
1.12E+1
1.07E+2
1.81E+1
1.62E+0
1.53E+2
2 .55E + 1
2 .77E+0
2 .94E + 0
2 .94E + 0
5.30E+1
8.83E+0
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E+1
6 .40E-1
3 .69E+0
1, 000
8 .20E-2
9 .84E+0
2 .90E-2
1 .67E-2
3 .32E+1
.OOE+0
1 .85E+0
1 .23E+1
5 .78E-1
1 .23E+1
1 .13E+1
9 .58E+1
4 .50E+0
9 .58E+1
1 .13E+1
1 .06E+1
1 .12E+1
5 .28E-1
1 .12E+1
1 .07E+2
1 .81E+1
1 .62E+0
1 .53E+2
2 .55E+1
8 .64E-1
1 .66E+0
1 .66E+0
5 .30E+1
8 .83E+0
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1 1
10, ooo||
i
8.20E-2
9.84E+0
2 .90E-2
1.67E-2
3 .32E+1
.OOE+0
1.85E+0
1.23E+1
5.78E-1
1.23E+1
1.13E+1
9.58E+1
4 .50E + 0
9.58E+1
1.13E+1
1.06E+1
1.12E+1
5.28E-1
1.12E+1
1.07E+2
1.81E+1
1.62E+0
1.53E+2
2 .55E+1
8.43E-1
1.64E+0
1.64E+0
5.30E+1
8.83E+0
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E + 0
-------
Table 8 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
XIIIC
XVIA
XVI B
XVI C
XVI I IA
XVI I IB
XVI I 1C
XXA
XXB
XXC
||XXIA
||XXIB
||xxic
XXII
1
U-238
U-235
U-234
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Th-232
Th-232
Th-232
Ra-226
Th-232
U-234
U-235
U-238
1
.10
100
3 .11E + 0
5.01E-2
2 .91E-1
2 .89E-2
.OOE+0
2 .89E-2
.OOE+0
2 .89E-2
.OOE+0
1.23E-1
1.23E-1
1.23E-1
1.23E-1
1.23E-1
1.23E-1
3 .09E+0
1.04E-1
5.30E-1
3 .09E+0
1.04E-1
5.30E-1
3 .09E+0
1.04E-1
5.30E-1
2 .26E-2
2 .26E-2
2 .26E-2
4 .02E-3
1.99E-2
2 .57E-5
1.21E-6
2 .57E-5
1
1, 000
3 .11E+0
5 .01E-2
2 .91E-1
2 .89E-2
.OOE+0
2 .89E-2
.OOE+0
2 .89E-2
.OOE+0
1 .23E-1
1 .23E-1
1 .23E-1
1 .23E-1
1 .23E-1
1 .23E-1
3 .09E+0
1 .04E-1
5 .30E-1
3 .09E+0
1 .04E-1
5 .30E-1
3 .09E+0
1 .04E-1
5 .30E-1
2 .26E-2
2 .26E-2
2 .26E-2
4 .02E-3
1 .99E-2
2 .56E-5
1 .20E-6
2 .56E-5
10, 000
3 .11E+0
5.01E-2
2 .91E-1
2 .89E-2
.OOE+0
2 .89E-2
.OOE+0
2 .89E-2
.OOE+0
1.23E-1
1.23E-1
1.23E-1
1.23E-1
1.23E-1
1.23E-1
3 .09E+0
1.04E-1
5.30E-1
3 .09E+0
1.04E-1
5.30E-1
3 .09E+0
1.04E-1
5.30E-1
2 .26E-2
2 .26E-2
2 .26E-2
4 .02E-3
1.99E-2
2 .56E-5
1.20E-6
2 .56E-5
.50
100
1 .56E+1
2 .49E-1
1 .46E+0
1 .45E-1
.OOE+0
1 .45E-1
.OOE+0
1 .45E-1
.OOE+0
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
1 .54E+1
5 .19E-1
2 .64E+0
1 .54E+1
5 .19E-1
2 .64E+0
1 .54E+1
5 .19E-1
2 .64E+0
1 .13E-1
1 .13E-1
1 .13E-1
1 .99E-2
9 .90E-2
3 .51E-3
1 .65E-4
3 .51E-3
1
1, 000
1.56E+1
2 .49E-1
1.46E+0
1.45E-1
.OOE+0
1.45E-1
.OOE+0
1.45E-1
.OOE+0
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
1.54E+1
5.19E-1
2 .64E + 0
1.54E+1
5.19E-1
2 .64E + 0
1.54E+1
5.19E-1
2 .64E + 0
1.13E-1
1.13E-1
1.13E-1
1.97E-2
9.77E-2
3 .37E-3
1.58E-4
3 .37E-3
10, 000
1 .56E+1
2 .49E-1
1 .46E+0
1 .45E-1
.OOE+0
1 .45E-1
.OOE+0
1 .45E-1
.OOE+0
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
6 .16E-1
1 .54E+1
5 .19E-1
2 .64E+0
1 .54E+1
5 .19E-1
2 .64E+0
1 .54E+1
5 .19E-1
2 .64E+0
1 .13E-1
1 .13E-1
1 .13E-1
1 .97E-2
9 .77E-2
3 .37E-3
1 .58E-4
3 .37E-3
1.00
100
3 .11E + 1
5.04E-1
2 .91E + 0
2 .89E-1
.OOE+0
2 .89E-1
.OOE+0
2 .89E-1
.OOE+0
1.23E+0
1.23E+0
1.23E+0
1.23E+0
1.23E+0
1.23E+0
3 .09E+1
1.04E+0
5.29E+0
3 .09E + 1
1.04E+0
5.29E+0
3 .09E + 1
1.04E+0
5.29E+0
2 .26E-1
2 .26E-1
2 .26E-1
3 .92E-2
1.95E-1
2 .82E-2
1.32E-3
2 .82E-2
1, 000
3 .11E+1
5 .04E-1
2 .91E+0
2 .89E-1
.OOE+0
2 .89E-1
.OOE+0
2 .89E-1
.OOE+0
1 .23E+0
1 .23E+0
1 .23E+0
1 .23E+0
1 .23E+0
1 .23E+0
3 .09E+1
1 .04E+0
5 .29E+0
3 .09E+1
1 .04E+0
5 .29E+0
3 .09E+1
1 .04E+0
5 .29E+0
2 .26E-1
2 .26E-1
2 .26E-1
3 .74E-2
1 .86E-1
2 .43E-2
1 .14E-3
2 .43E-2
10, 000
3 .11E+1
5.04E-1
2 .91E+0
2 .89E-1
.OOE+0
2 .89E-1
.OOE+0
2 .89E-1
.OOE+0
1.23E+0
1.23E+0
1.23E+0
1.23E+0
1.23E+0
1.23E+0
3 .09E + 1
1.04E+0
5.29E+0
3 .09E + 1
1.04E+0
5.29E+0
3 .09E + 1
1.04E+0
5.29E+0
2 .26E-1
2 .26E-1
2 .26E-1
3 .74E-2
1.86E-1
2 .43E-2
1.14E-3
2 .43E-2
3 .00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
8 .62E-1
2 .44E-2
8 .62E-1
2 .44E-2
8 .62E-1
2 .44E-2
3 .70E+0
3 .70E+0
3 .70E+0
3 .70E+0
3 .70E+0
3 .70E+0
9 .26E+1
3 .12E+0
1 .59E+1
9 .26E+1
3 .12E+0
1 .59E+1
9 .26E+1
3 .12E+0
1 .59E+1
6 .79E-1
6 .79E-1
6 .79E-1
1 .05E-1
5 .24E-1
5 .79E-1
2 .72E-2
5 .79E-1
1, 000
3 .94E + 1
6 .40E-1
3 .69E+0
8.62E-1
2 .44E-2
8.62E-1
2 .44E-2
8.62E-1
2 .44E-2
3 .70E + 0
3 .70E + 0
3 .70E + 0
3 .70E + 0
3 .70E + 0
3 .70E + 0
9.26E+1
3 .12E + 0
1.59E+1
9.26E+1
3 .12E + 0
1.59E+1
9.26E+1
3 .12E+0
1.59E+1
6 .79E-1
6 .79E-1
6 .79E-1
8.64E-2
4 .32E-1
3 .19E-1
1.50E-2
3 .19E-1
10, 000
3 .94E+1
6 .40E-1
3 .69E + 0
8 .62E-1
2 .44E-2
8 .62E-1
2 .44E-2
8 .62E-1
2 .44E-2
3 .70E+0
3 .70E+0
3 .70E+0
3 .70E+0
3 .70E+0
3 .70E+0
9 .26E+1
3 .12E+0
1 .59E+1
9 .26E+1
3 .12E+0
1 .59E+1
9 .26E+1
3 .12E+0
1 .59E+1
6 .79E-1
6 .79E-1
6 .79E-1
8 .64E-2
4 .32E-1
3 .19E-1
1 .50E-2
3 .19E-1
5.00 ||
100
3 .94E+1
6 .40E-1
3 .69E+0
1.39E+0
2 .38E-1
1.39E+0
2 .38E-1
1.39E+0
2 .38E-1
6 .16E + 0
6 .16E+0
6 .16E+0
6 .16E + 0
6 .16E + 0
6 .16E+0
1.54E+2
5.20E+0
2 .65E + 1
1.54E+2
5.20E+0
2 .65E+1
1.54E+2
5.20E+0
2 .65E + 1
1.13E+0
1.13E+0
1.13E+0
1.69E-1
8.47E-1
1.17E+0
5.52E-2
1.17E+0
1, 000
3 .94E + 1
6 .40E-1
3 .69E + 0
1 .39E + 0
2 .38E-1
1 .39E+0
2 .38E-1
1 .39E+0
2 .38E-1
6 .16E+0
6 .16E+0
6 .16E+0
6 .16E+0
6 .16E+0
6 .16E+0
1 .54E+2
5 .20E+0
2 .65E+1
1 .54E+2
5 .20E+0
2 .65E+1
1 .54E+2
5 .20E+0
2 .65E+1
1 .13E+0
1 .13E+0
1 .13E+0
1 .16E-1
5 .82E-1
7 .97E-1
3 .75E-2
7 .97E-1
1 1
10, ooo||
3 .94E + 1
6 .40E-1
3 .69E + 0
1.39E+o|
2 .38E-l||
1.39E+o|
2 .38E-l||
1.39E+o|
2 .38E-l||
6 .16E+o|
6 .16E + o||
6 .16E+o|
6 .16E + o||
6 .16E+o|
6 .16E + o||
1.54E+2
5.20E+0
2 .65E + 1
1.54E+2
5.20E+0
2 .65E + 1
1.54E+2
5.20E+0
2 .65E + 1
1.13E + o||
1.13E + o||
1.13E + o||
1.16E-1
5.82E-1
7.97E-1
3 .75E-2
7.97E-1
-------
Table 8 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
|| I
II-l
II-2
II-3
II-4
II-5
1
Nluclide -
Cs-137
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
1
10 .00
100
2 .27E + 1
2 .40E + 0
1.62E+1
1.04E-2
7.97E-3
6 .59E-2
2 .84E-3
8.41E-2
1.21E-2
4 .16E+1
7.35E-1
3 .86E-2
4 .19E+0
2 .82E-1
5.27E+0
3 .18E-1
6 .96E+0
4 .33E-2
4 .23E-2
1.81E+1
4 .80E+0
1.66E+1
1.08E-2
3 .17E+1
4 .08E-1
4 .06E-1
3 .77E+0
2 .15E-3
5.79E-2
3 .05E+0
1.40E-2
1.82E-2
3 .28E-2
.OOE+0
8.37E-4
1.80E-2
1
1, 000
2 .27E+1
1 .45E+0
1 .53E+1
1 .04E-2
7 .96E-3
6 .58E-2
2 .84E-3
8 .08E-2
1 .19E-2
2 .49E+1
5 .16E-2
3 .77E-2
4 .04E+0
2 .72E-1
5 .08E+0
2 .96E-1
6 .30E+0
4 .24E-2
4 .15E-2
1 .59E+1
4 .23E+0
1 .45E+1
9 .05E-3
2 .14E+1
2 .30E-1
1 .70E-1
1 .97E+0
1 .38E-3
4 .84E-2
3 .05E+0
1 .40E-2
1 .82E-2
3 .28E-2
.OOE+0
8 .37E-4
1 .80E-2
10, 000
2 .27E+1
1.45E+0
1.53E+1
1.04E-2
7.96E-3
6 .58E-2
2 .84E-3
8.08E-2
1.19E-2
2 .49E+1
5.16E-2
3 .77E-2
4 .04E+0
2 .72E-1
5.08E+0
2 .96E-1
6 .30E+0
4 .24E-2
4 .15E-2
1.59E+1
4 .23E+0
1.45E+1
9.05E-3
2 .14E+1
2 .30E-1
1.70E-1
1.97E+0
1.38E-3
4 .84E-2
3 .05E+0
1.40E-2
1.82E-2
3 .28E-2
.OOE+0
8.37E-4
1.80E-2
15.00
100
3 .40E+1
4 .OOE+0
1 .75E+1
1 .04E-2
8 .OOE-3
6 .60E-2
2 .85E-3
8 .90E-2
1 .23E-2
5 .45E+1
1 .72E+0
3 .93E-2
4 .32E+0
2 .89E-1
5 .41E+0
3 .95E-1
9 .49E+0
4 .62E-2
4 .52E-2
2 .74E+1
7 .10E+0
2 .56E+1
1 .22E-1
4 .08E+1
6 .28E-1
7 .11E-1
7 .OOE+0
1 .61E-2
7 .68E-1
4 .56E+0
1 .49E-2
1 .98E-2
8 .15E-2
.OOE+0
9 .05E-4
1 .91E-2
1
1, 000
3 .40E + 1
2 .98E + 0
1.65E+1
1.04E-2
7.98E-3
6 .59E-2
2 .85E-3
8.53E-2
1.20E-2
3 .58E+1
4 .08E-1
3 .83E-2
4 .14E+0
2 .78E-1
5.20E+0
3 .71E-1
8.66E+0
4 .53E-2
4 .43E-2
2 .42E+1
6 .33E+0
2 .25E+1
1.05E-2
2 .98E+1
3 .75E-1
3 .62E-1
3 .39E+0
2 .01E-3
5.62E-2
4 .56E+0
1.49E-2
1.98E-2
8.14E-2
.OOE+0
9.05E-4
1.91E-2
10, 000
3 .40E + 1
2 .98E+0
1 .65E+1
1 .04E-2
7 .98E-3
6 .59E-2
2 .85E-3
8 .53E-2
1 .20E-2
3 .58E+1
4 .08E-1
3 .83E-2
4 .14E+0
2 .78E-1
5 .20E+0
3 .71E-1
8 .66E+0
4 .53E-2
4 .43E-2
2 .42E+1
6 .33E+0
2 .25E+1
1 .05E-2
2 .98E+1
3 .75E-1
3 .62E-1
3 .39E+0
2 .01E-3
5 .62E-2
4 .56E+0
1 .49E-2
1 .98E-2
8 .14E-2
.OOE+0
9 .05E-4
1 .91E-2
25.00
100
5.67E+1
7.11E+0
2 .19E+1
1.05E-2
8.09E-3
6 .66E-2
2 .89E-3
1.08E-1
1.26E-2
7.97E+1
3 .71E+0
4 .07E-2
4 .60E+0
3 .06E-1
5.73E+0
4 .85E-1
1.36E+1
4 .97E-2
3 .97E-1
4 .13E+1
1.05E+1
3 .93E+1
3 .77E-1
5.52E+1
1.07E+0
1.38E+0
1.77E+1
1.77E-1
4 .04E+0
7.51E+0
1.67E-2
2 .31E-2
2 .32E-1
.OOE+0
1.04E-3
2 .14E-2
1, 000
5 .67E+1
5 .90E+0
2 .01E+1
1 .05E-2
8 .05E-3
6 .64E-2
2 .87E-3
1 .OOE-1
1 .22E-2
5 .36E+1
1 .65E+0
3 .92E-2
4 .31E+0
2 .89E-1
5 .40E+0
4 .67E-1
1 .25E+1
4 .90E-2
2 .82E-1
3 .83E+1
9 .78E+0
3 .63E+1
1 .64E-1
4 .32E+1
6 .99E-1
8 .22E-1
8 .35E+0
3 .40E-2
1 .12E+0
7 .51E+0
1 .67E-2
2 .31E-2
2 .32E-1
.OOE+0
1 .04E-3
2 .14E-2
10, 000
5.67E+1
5.90E+0
2 .01E+1
1.05E-2
8.05E-3
6 .64E-2
2 .87E-3
1. OOE-1
1.22E-2
5.36E+1
1.65E+0
3 .92E-2
4 .31E+0
2 .89E-1
5.40E+0
4 .67E-1
1.25E+1
4 .90E-2
2 .82E-1
3 .83E + 1
9.78E+0
3 .63E+1
1.64E-1
4 .32E + 1
6 .99E-1
8.22E-1
8.35E+0
3 .40E-2
1.12E+0
7.51E+0
1.67E-2
2 .31E-2
2 .32E-1
.OOE+0
1.04E-3
2 .14E-2
75.00
100
1 .70E+2
2 .30E+1
3 .77E+1
1 .09E-2
8 .42E-3
6 .85E-2
3 .02E-3
1 .91E-1
1 .43E-2
1 .87E+2
1 .15E+1
1 .98E+0
5 .85E+0
3 .82E-1
7 .22E+0
7 .16E-1
3 .11E+1
1 .41E+0
2 .91E+0
1 .17E+2
2 .18E+1
1 .09E+2
1 .29E+0
1 .08E+2
2 .94E+0
4 .74E+0
2 .04E+2
3 .93E+0
8 .08E+1
2 .04E+1
2 .68E-2
8 .77E-1
1 .40E+0
.OOE+0
1 .79E-3
3 .44E-2
1, 000
1.70E+2
2 .08E + 1
3 .57E + 1
1.08E-2
8.37E-3
6 .83E-2
3 .OOE-3
1.80E-1
1.35E-2
1.37E+2
7.84E+0
4 .50E-1
5.26E+0
3 .45E-1
6 .49E + 0
6 .99E-1
2 .95E + 1
1.22E+0
2 .61E + 0
1.06E+2
2 .08E + 1
9.93E+1
1.01E+0
9.20E+1
2 .34E + 0
3 .57E + 0
1.05E+2
2 .OOE + 0
4 .17E + 1
2 .04E + 1
2 .68E-2
8.77E-1
1.40E+0
.OOE+0
1.79E-3
3 .44E-2
10, 000
1 .70E+2
2 .08E+1
3 .57E+1
1 .08E-2
8 .37E-3
6 .83E-2
3 .OOE-3
1 .80E-1
1 .35E-2
1 .37E+2
7 .84E+0
4 .50E-1
5 .26E+0
3 .45E-1
6 .49E+0
6 .99E-1
2 .95E+1
1 .22E+0
2 .61E+0
1 .06E+2
2 .08E+1
9 .93E+1
1 .01E+0
9 .20E+1
2 .34E+0
3 .57E+0
1 .05E+2
2 .OOE+0
4 .17E+1
2 .04E+1
2 .68E-2
8 .77E-1
1 .40E+0
.OOE+0
1 .79E-3
3 .44E-2
100.00 ||
100
2 .27E + 2
3 .10E+1
4 .51E + 1
1.11E-2
8.58E-3
6 .95E-2
3 .08E-3
2 .36E-1
1.50E-2
2 .36E+2
1.49E+1
3 .35E + 0
6 .47E + 0
4 .21E-1
7.99E+0
7.79E-1
3 .67E+1
2 .19E + 0
4 .16E+0
1.57E+2
2 .52E+1
1.49E+2
1.61E+0
1.18E+2
3 .72E + 0
6 .32E + 0
3 .45E + 2
8.75E+0
1.93E+2
2 .63E+1
3 .18E-2
1.42E+0
2 .16E + 0
.OOE+0
2 .16E-3
4 .08E-2
1, 000
2 .27E + 2
2 .83E+1
4 .26E+1
1 .10E-2
8 .52E-3
6 .92E-2
3 .06E-3
2 .20E-1
1 .40E-2
1 .71E+2
1 .03E+1
1 .52E+0
5 .66E+0
3 .70E-1
6 .98E+0
7 .63E-1
3 .52E+1
1 .97E+0
3 .81E+0
1 .46E+2
2 .43E+1
1 .38E+2
1 .34E+0
1 .11E+2
3 .05E+0
4 .95E+0
2 .23E+2
4 .56E+0
9 .31E+1
2 .63E+1
3 .18E-2
1 .42E+0
2 .16E+0
.OOE+0
2 .16E-3
4 .08E-2
1 1
10, ooo||
i
2 .27E+2
2 .83E+1
4 .26E+1
1.10E-2
8.52E-3
6 .92E-2
3 .06E-3
2 .20E-1
1.40E-2
1.71E+2
1.03E+1
1.52E+0
5.66E+0
3 .70E-1
6 .98E + 0
7.63E-1
3 .52E + 1
1.97E+0
3 .81E + 0
1.46E+2
2 .43E+1
1.38E+2
1.34E+0
1.11E+2
3 .05E+0
4 .95E + 0
2 .23E+2
4 .56E+0
9.31E+1
2 .63E+1
3 .18E-2
1.42E+0
2 .16E+0
.OOE+0
2 .16E-3
4 .08E-2
-------
Table 8 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
II-6
II-7
|| III
IV
||v
VI
VII
IX
X
XII
XIIIA
XIIIB
1
Ra-226
Th-230
Ra-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
1
10 .00
100
1.52E+0
1.74E+1
2 .87E-1
1.89E-2
4 .79E+1
.OOE+0
2 .51E+0
1.23E+1
5.78E-1
1.23E+1
2 .27E+1
1.92E+2
9. OOE+0
1.92E+2
2 .27E+1
2 .04E+1
3 .44E+1
1.62E+0
3 .44E+1
2 .05E+2
3 .38E+1
4 .OOE+0
3 .06E+2
5.10E+1
8.55E+0
5.44E+0
5.44E+0
1.06E+2
1.77E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1
1, 000
4 .46E-1
1 .71E+1
2 .70E-1
1 .88E-2
4 .73E+1
.OOE+0
2 .48E+0
1 .23E+1
5 .78E-1
1 .23E+1
2 .27E+1
1 .92E+2
9 .OOE+0
1 .92E+2
2 .27E+1
2 .04E+1
3 .44E+1
1 .62E+0
3 .44E+1
2 .05E+2
3 .38E+1
4 .OOE+0
3 .06E+2
5 .10E+1
3 .28E+0
3 .21E+0
3 .21E+0
1 .06E+2
1 .77E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
10, 000
4 .46E-1
1.71E+1
2 .70E-1
1.88E-2
4 .73E+1
.OOE+0
2 .48E+0
1.23E+1
5.78E-1
1.23E+1
2 .27E+1
1.92E+2
9. OOE+0
1.92E+2
2 .27E+1
2 .04E+1
3 .44E+1
1.62E+0
3 .44E+1
2 .05E+2
3 .38E+1
4 .OOE+0
3 .06E+2
5.10E+1
3 .22E+0
3 .16E+0
3 .16E+0
1.06E+2
1.77E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
15.00
100
3 .11E+0
1 .80E+1
3 .24E-1
1 .91E-2
4 .92E+1
.OOE+0
2 .57E+0
1 .23E+1
5 .78E-1
1 .23E+1
3 .40E+1
2 .87E+2
1 .35E+1
2 .87E+2
3 .40E+1
2 .99E+1
6 .26E+1
2 .94E+0
6 .26E+1
3 .08E+2
5 .13E+1
5 .89E+0
4 .59E+2
7 .65E+1
1 .87E+1
7 .27E+0
7 .27E+0
1 .59E+2
2 .65E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1
1, 000
2 .02E+0
1.76E+1
3 .OOE-1
1.90E-2
4 .83E + 1
.OOE+0
2 .53E+0
1.23E+1
5.78E-1
1.23E+1
3 .40E + 1
2 .87E+2
1.35E+1
2 .87E+2
3 .40E+1
2 .99E+1
6 .26E+1
2 .94E+0
6 .26E+1
3 .08E+2
5.13E+1
5.89E+0
4 .59E+2
7.65E+1
6 .25E+0
4 .71E + 0
4 .71E+0
1.59E+2
2 .65E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
10, 000
2 .02E + 0
1 .76E+1
3 .OOE-1
1 .90E-2
4 .83E+1
.OOE+0
2 .53E+0
1 .23E+1
5 .78E-1
1 .23E+1
3 .40E+1
2 .87E+2
1 .35E+1
2 .87E+2
3 .40E+1
2 .99E+1
6 .26E+1
2 .94E+0
6 .26E+1
3 .08E+2
5 .13E+1
5 .89E+0
4 .59E+2
7 .65E+1
6 .08E+0
4 .64E+0
4 .64E+0
1 .59E+2
2 .65E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
25.00
100
6 .29E + 0
1.93E+1
3 .94E-1
1.95E-2
5.16E+1
.OOE+0
2 .68E+0
1.23E+1
5.78E-1
1.23E+1
5.67E+1
4 .79E+2
2 .25E+1
4 .79E+2
5.67E+1
4 .80E+1
1.31E+2
6 .18E + 0
1.31E+2
5.19E+2
8.68E+1
9.42E+0
7.65E+2
1.28E+2
4 .85E+1
9.52E+0
9.52E+0
2 .65E+2
4 .42E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1, 000
5 .12E+0
1 .88E+1
3 .70E-1
1 .93E-2
5 .07E+1
.OOE+0
2 .64E+0
1 .23E+1
5 .78E-1
1 .23E+1
5 .67E+1
4 .79E+2
2 .25E+1
4 .79E+2
5 .67E+1
4 .80E+1
1 .31E+2
6 .18E+0
1 .31E+2
5 .19E+2
8 .68E+1
9 .42E+0
7 .65E+2
1 .28E+2
1 .85E+1
7 .23E+0
7 .23E+0
2 .65E+2
4 .42E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
10, 000
5.12E+0
1.88E+1
3 .70E-1
1.93E-2
5.07E+1
.OOE+0
2 .64E + 0
1.23E+1
5.78E-1
1.23E+1
5.67E+1
4 .79E+2
2 .25E+1
4 .79E+2
5.67E+1
4 .80E+1
1.31E+2
6 .18E+0
1.31E+2
5.19E+2
8.68E+1
9.42E+0
7.65E+2
1.28E+2
1.79E+1
7.16E+0
7.16E+0
2 .65E+2
4 .42E+1
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
75.00
100
2 .22E + 1
2 .42E + 1
7 .56E-1
7 .13E-2
6 .44E+1
.OOE+0
3 .35E+0
1 .23E+1
5 .78E-1
1 .23E+1
1 .50E+2
1 .44E+3
6 .75E+1
1 .44E+3
1 .70E+2
1 .35E+2
5 .37E+2
2 .52E+1
5 .37E+2
1 .46E+3
2 .43E+2
3 .60E+1
2 .30E+3
3 .83E+2
2 .25E+2
1 .66E+1
1 .66E+1
7 .96E+2
1 .33E+2
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1, 000
2 .07E + 1
2 .38E + 1
7.23E-1
6 .58E-2
6 .32E + 1
.OOE+0
3 .29E+0
1.23E+1
5.78E-1
1.23E+1
1.50E+2
1.44E+3
6 .75E + 1
1.44E+3
1.70E+2
1.35E+2
5.37E+2
2 .52E + 1
5.37E+2
1.46E+3
2 .43E + 2
3 .60E + 1
2 .30E + 3
3 .83E + 2
1.56E+2
1.39E+1
1.39E+1
7.96E+2
1.33E+2
3 .94E+1
6 .40E-1
3 .69E + 0
3 .94E+1
6 .40E-1
3 .69E + 0
10, 000
2 .07E+1
2 .38E+1
7 .23E-1
6 .58E-2
6 .32E+1
.OOE+0
3 .29E+0
1 .23E+1
5 .78E-1
1 .23E+1
1 .50E+2
1 .44E+3
6 .75E+1
1 .44E+3
1 .70E+2
1 .35E+2
5 .37E+2
2 .52E+1
5 .37E+2
1 .46E+3
2 .43E+2
3 .60E+1
2 .30E+3
3 .83E+2
1 .54E+2
1 .38E+1
1 .38E+1
7 .96E+2
1 .33E+2
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E + 0
100.00 ||
100
3 .02E+1
2 .65E + 1
9.24E-1
1. OOE-1
7.09E+1
.OOE+0
3 .71E + 0
1.23E+1
5.78E-1
1.23E+1
1.50E+2
1.92E+3
9.00E+1
1.92E+3
2 .27E + 2
1.82E+2
6 .75E + 2
3 .17E+1
6 .75E + 2
1.50E+3
2 .50E + 2
8.00E+1
2 .98E + 3
4 .97E+2
3 .19E + 2
1.93E+1
1.93E+1
1.06E+3
1.77E+2
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E+1
6 .40E-1
3 .69E + 0
1, 000
2 .86E+1
2 .60E+1
8 .91E-1
9 .45E-2
6 .96E+1
.OOE+0
3 .63E+0
1 .23E+1
5 .78E-1
1 .23E + 1
1 .50E+2
1 .92E+3
9 .OOE+1
1 .92E+3
2 .27E+2
1 .82E+2
6 .75E+2
3 .17E+1
6 .75E+2
1 .50E+3
2 .50E+2
8 .OOE+1
2 .98E+3
4 .97E+2
2 .31E+2
1 .68E+1
1 .68E+1
1 .06E+3
1 .77E+2
3 .94E+1
6 .40E-1
3 .69E+0
3 .94E+1
6 .40E-1
3 .69E+0
1 1
10, ooo||
i
2 .86E + 1
2 .60E + 1
8.91E-1
9.45E-2
6 .96E+1
.OOE+0
3 .63E + 0
1.23E+1
5.78E-1
1.23E+1
1.50E+2
1.92E+3
9. OOE + 1
1.92E+3
2 .27E+2
1.82E+2
6 .75E+2
3 .17E+1
6 .75E+2
1.50E+3
2 .50E+2
8. OOE + 1
2 .98E+3
4 .97E+2
2 .28E+2
1.67E+1
1.67E+1
1.06E+3
1.77E+2
3 .94E + 1
6 .40E-1
3 .69E + 0
3 .94E + 1
6 .40E-1
3 .69E + 0
-------
Table 8 Continued
07-21-95 5:22p--30-y delay for Reference Sites I, III and V. R.S. I based on 1978 aerial survey
MAXIMUM RESIDUAL CONCENTRATION (pCi/g)--Indoor radon pathway excluded from RME health effects
CLEANUP GOAL BASED ON SITE-SPECIFIC DOSE LIMITS (mrem/yr) FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
Ref .
|site
||NO.
1
XIIIC
XVIA
XVI B
XVI C
XVI I IA
XVI I IB
XVI I 1C
XXA
XXB
XXC
||XXIA
||XXIB
||xxic
XXII
1
U-238
U-235
U-234
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Th-232
Th-232
Th-232
Ra-226
Th-232
U-234
U-235
U-238
1
10 .00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
2 .74E + 0
6 .52E-1
2 .74E + 0
6 .52E-1
2 .74E + 0
6 .52E-1
1.23E+1
1.23E+1
1.23E+1
1.23E+1
1.23E+1
1.23E+1
3 .09E + 2
1.04E+1
5.29E+1
3 .09E + 2
1.04E+1
5.29E+1
3 .09E + 2
1.04E+1
5.29E+1
2 .26E + 0
2 .26E + 0
2 .26E + 0
2 .45E-1
1.89E+0
1.44E+0
6 .75E-2
1.44E+0
1
1, 000
3 .94E+1
6 .40E-1
3 .69E+0
2 .74E+0
6 .52E-1
2 .74E+0
6 .52E-1
2 .74E+0
6 .52E-1
1 .23E+1
1 .23E+1
1 .23E+1
1 .23E+1
1 .23E+1
1 .23E+1
3 .09E+2
1 .04E+1
5 .29E+1
3 .09E+2
1 .04E+1
5 .29E+1
3 .09E+2
1 .04E+1
5 .29E+1
2 .26E+0
2 .26E+0
2 .26E+0
2 .18E-1
1 .32E+0
1 .35E+0
6 .33E-2
1 .35E+0
10, 000
3 .94E+1
6 .40E-1
3 .69E+0
2 .74E+0
6 .52E-1
2 .74E+0
6 .52E-1
2 .74E+0
6 .52E-1
1.23E+1
1.23E+1
1.23E+1
1.23E+1
1.23E+1
1.23E+1
3 .09E+2
1.04E+1
5.29E+1
3 .09E+2
1.04E+1
5.29E+1
3 .09E+2
1.04E+1
5.29E+1
2 .26E+0
2 .26E+0
2 .26E+0
2 .18E-1
1.32E+0
1.35E+0
6 .33E-2
1.35E+0
15.00
100
3 .94E+1
6 .40E-1
3 .69E + 0
4 .13E+0
8 .68E-1
4 .13E+0
8 .68E-1
4 .13E+0
8 .68E-1
1 .85E+1
1 .85E+1
1 .85E+1
1 .85E+1
1 .85E+1
1 .85E+1
4 .63E+2
1 .56E+1
7 .94E+1
4 .63E+2
1 .56E+1
7 .94E+1
4 .63E+2
1 .56E+1
7 .94E+1
3 .39E+0
3 .39E+0
3 .39E+0
4 .66E-1
2 .82E+0
1 .80E+0
8 .48E-2
1 .80E+0
1
1, 000
3 .94E+1
6 .40E-1
3 .69E + 0
4 .13E+0
8.68E-1
4 .13E + 0
8.68E-1
4 .13E + 0
8.68E-1
1.85E+1
1.85E+1
1.85E+1
1.85E+1
1.85E+1
1.85E+1
4 .63E + 2
1.56E+1
7.94E+1
4 .63E + 2
1.56E+1
7.94E+1
4 .63E + 2
1.56E+1
7.94E+1
3 .39E + 0
3 .39E + 0
3 .39E + 0
3 .12E-1
2 .26E + 0
1.57E+0
7.36E-2
1.57E+0
10, 000
3 .94E + 1
6 .40E-1
3 .69E + 0
4 .13E+0
8 .68E-1
4 .13E+0
8 .68E-1
4 .13E+0
8 .68E-1
1 .85E+1
1 .85E+1
1 .85E+1
1 .85E+1
1 .85E+1
1 .85E+1
4 .63E+2
1 .56E+1
7 .94E+1
4 .63E+2
1 .56E+1
7 .94E+1
4 .63E+2
1 .56E+1
7 .94E+1
3 .39E+0
3 .39E+0
3 .39E+0
3 .12E-1
2 .26E+0
1 .57E+0
7 .36E-2
1 .57E+0
25.00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
6 .95E + 0
1.19E+0
6 .95E+0
1.19E+0
6 .95E+0
1.19E+0
3 .08E+1
3 .08E + 1
3 .08E + 1
3 .08E+1
3 .08E + 1
3 .08E + 1
7.72E+2
2 .60E+1
1.32E+2
7.72E+2
2 .60E+1
1.32E+2
7.72E+2
2 .60E+1
1.32E+2
5.66E+0
5.66E+0
5.66E+0
9.72E-1
4 .39E+0
4 .20E+0
1.98E-1
4 .20E+0
1, 000
3 .94E+1
6 .40E-1
3 .69E+0
6 .95E+0
1 .19E+0
6 .95E+0
1 .19E+0
6 .95E+0
1 .19E+0
3 .08E+1
3 .08E+1
3 .08E+1
3 .08E+1
3 .08E+1
3 .08E+1
7 .72E+2
2 .60E+1
1 .32E+2
7 .72E+2
2 .60E+1
1 .32E+2
7 .72E+2
2 .60E+1
1 .32E+2
5 .66E+0
5 .66E+0
5 .66E+0
7 .51E-1
3 .58E+0
2 .66E+0
1 .25E-1
2 .66E+0
10, 000
3 .94E+1
6 .40E-1
3 .69E+0
6 .95E+0
1.19E+0
6 .95E+0
1.19E+0
6 .95E+0
1.19E+0
3 .08E+1
3 .08E+1
3 .08E+1
3 .08E+1
3 .08E+1
3 .08E+1
7.72E+2
2 .60E+1
1.32E+2
7.72E+2
2 .60E+1
1.32E+2
7.72E+2
2 .60E + 1
1.32E+2
5.66E+0
5.66E+0
5.66E+0
7.51E-1
3 .58E + 0
2 .66E + 0
1.25E-1
2 .66E + 0
75.00
100
3 .94E + 1
6 .40E-1
3 .69E + 0
2 .08E+1
3 .68E+0
2 .08E+1
3 .68E+0
2 .08E+1
3 .68E+0
9 .24E+1
9 .24E+1
9 .24E+1
9 .24E+1
9 .24E+1
9 .24E+1
2 .33E+3
7 .58E+1
3 .99E+2
2 .33E+3
7 .58E+1
3 .99E+2
2 .33E+3
7 .58E+1
3 .99E+2
1 .70E+1
1 .70E+1
1 .70E+1
1 .39E+0
1 .48E+1
8 .56E+0
4 .02E-1
8 .56E+0
1, 000
3 .94E + 1
6 .40E-1
3 .69E+0
2 .08E + 1
3 .68E + 0
2 .08E+1
3 .68E + 0
2 .08E + 1
3 .68E + 0
9.24E+1
9.24E+1
9.24E+1
9.24E+1
9.24E+1
9.24E+1
2 .33E + 3
7.58E+1
3 .99E+2
2 .33E + 3
7.58E+1
3 .99E+2
2 .33E + 3
7.58E+1
3 .99E+2
1.70E+1
1.70E+1
1.70E+1
1.29E+0
1.18E+1
7.30E+0
3 .43E-1
7.30E+0
10, 000
3 .94E+1
6 .40E-1
3 .69E + 0
2 .08E+1
3 .68E+0
2 .08E+1
3 .68E+0
2 .08E+1
3 .68E+0
9 .24E+1
9 .24E+1
9 .24E+1
9 .24E+1
9 .24E + 1
9 .24E+1
2 .33E+3
7 .58E+1
3 .99E+2
2 .33E+3
7 .58E+1
3 .99E+2
2 .33E+3
7 .58E+1
3 .99E+2
1 .70E+1
1 .70E+1
1 .70E+1
1 .29E+0
1 .18E+1
7 .30E+0
3 .43E-1
7 .30E+0
100.00 ||
100
3 .94E+1
6 .40E-1
3 .69E+0
2 .77E + 1
5.12E+0
2 .77E + 1
5.12E+0
2 .77E + 1
5.12E+0
1.23E+2
1.23E+2
1.23E+2
1.23E+2
1.23E+2
1.23E+2
3 .12E + 3
9.86E+1
5.36E+2
3 .12E + 3
9.86E+1
5.36E+2
3 .12E + 3
9.86E+1
5.36E+2
2 .26E+1
2 .26E+1
2 .26E + 1
2 .20E + 0
1.86E+1
1.74E+1
8.18E-1
1.74E+1
1, 000
3 .94E + 1
6 .40E-1
3 .69E + 0
2 .77E+1
5 .12E+0
2 .77E+1
5 .12E+0
2 .77E+1
5 .12E+0
1 .23E+2
1 .23E+2
1 .23E+2
1 .23E+2
1 .23E + 2
1 .23E+2
3 .12E+3
9 .86E+1
5 .36E+2
3 .12E+3
9 .86E+1
5 .36E+2
3 .12E+3
9 .86E+1
5 .36E+2
2 .26E+1
2 .26E+1
2 .26E+1
1 .44E+0
1 .61E+1
9 .47E+0
4 .45E-1
9 .47E+0
1 1
10, ooo||
3 .94E + 1
6 .40E-1
3 .69E + 0
2 .77E + l|
5.12E + o||
2 .77E + l|
5.12E + o||
2 .77E + l|
5.12E + o||
1.23E + 2II
1.23E + 2||
1.23E + 2II
1.23E + 2||
1.23E + 2II
1.23E + 2||
3 .12E+3
9.86E+1
5.36E+2
3 .12E+3
9.86E+1
5.36E+2
3 .12E+3
9.86E+1
5.36E+2
2 .26E + l||
2 .26E + l||
2 .26E + l||
1.44E+0
1.61E+1
9.47E+0
4 .45E-1
9.47E+0
-------
NOTICE
The information provided in this draft document is intended for internal review and comment
by the U.S. Environmental Protection Agency (EPA) only; it does not represent final EPA
policy, action, or guidance. The data, analyses, and conclusions presented in this report are
preliminary findings which are subject to revision without notice during the EPA review
process. Do not quote from, or reproduce parts of, this report.
Review Draft - 9/26/94 Xlll Do Not Cite or Quote
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ACKNOWLEDGEMENTS
This Draft Technical Support Document for the Development ofRadionuclide Cleanup Levels
for Soil contains the methodology and products of an effort that has involved the input of
dozens of individuals.
EPA personnel responsible for management of the project include Margo Oge (Director,
Office of Radiation and Indoor Air), Eugene Durman (Acting Director, Radiation Studies
Division), Nicholas Lailas (Chief, Radiation Assessment Branch), Dr. Anthony Wolbarst
(Chief, Remedial Guidance Section), H. Benjamin Hull (Team Leader), Mark Doehnert, and
John MacKinney.
Constructive suggestions, critiques of parts of the Draft Report, and other forms of help were
provided by Michael Boyd, Dr. Gordon Burley, Jamie Burnett, Michael Callahan, Dr. Mary
Clark, Capt. Clinton Cox (USPHS), Dr. John Davidson, Janine Dinan, Subijoy Dutta,
Barbara Hostage, Dr. Cheng Hung, Eugene Jablonowski, Lynn Johnson, Dr. Kachig
Kooyoomjian, Cdr. Colleen Petullo (USPHS), Dr. Jerome Puskin, Jon Richards, Allan
Richardson, Peter Tsirigotis, Stuart Walker, Ronald Wilhelm, and Karen Woods for EPA;
Frank Cardile, Chris Daily, and Dr. Robert Meek for NRC; Dr. Harold Peterson and Andrew
Wallo III for DOE; Michael Barisky, Lcdr. Garry Higgins, Capt. James Malinowski, and
Joseph Schroeder for DOD; and many others.
Technical support was provided by S. Cohen and Associates, Inc., under Contract No.
68D20155, Work Assignment 3-06.
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Introduction
The U.S. Environmental Protection Agency (EPA) is proposing regulations that set standards
for radiation doses received by members of the public as a result of radionuclide
contamination on sites under the control of a Federal Agency, and on sites licensed by the
Nuclear Regulatory Commission (NRC) or an NRC Agreement State, that are to be released
from those licenses or control. The proposed rule will ensure that such sites are cleaned up to
a level that is protective of human health and the environment before they are released for
public use. This document describes parts of the technical analysis being undertaken in
support of those regulations.
EPA is separately developing regulations that will address the disposal of radioactive waste
generated during site remediation, and will explore the feasibility of additional regulations
that deal with the recycle or reuse of equipment and materials after cleanup.
Background
The total number of sites contaminated with radionuclides in the United States is in the
thousands. Contaminated sites range in size from corners of laboratories to sprawling nuclear
weapons facilities covering many square miles of land. The contamination extends to all
environmental media, as well as to onsite buildings and equipment.
EPA's proposed regulations will set forth clear standards for the remediation of sites
contaminated with radionuclides and for the release of those sites for use by members of the
public. The regulations will utilize the authority granted to the EPA under the Atomic Energy
Act (AEA), and will apply to sites and facilities under the control of the Federal Government
or licensed by the NRC or any of its Agreement States.
EPA's Issues Paper on Radiation Site Cleanup Regulations(EPA 93 a) presents an overview
of the major policy issues, options, and preliminary analyses relevant to the development of
the proposed rule. Specifically, thelssues Paper describes the scope of the cleanup problem,
summarizes the statutory authorities available to EPA for developing the regulations, and
discusses the advantages and disadvantages of various regulatory approaches.
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Technical Analysis Supporting the Rule
The cleanup regulations will benefit society by reducing the number of potential adverse
health effects among the people living or working on or near a site following the cleanup of
its radioactive contamination. The magnitude of that benefit will depend on the cleanup level
selected. At the same time, implementation of the regulations will impose costs on the nation.
These costs, too, will depend on the cleanup level selected, and will include not only the
economic costs of remediation, but also the public health and ecological impacts of the
remediation effort itself.
In support of this rulemaking, EPA is conducting a comprehensive technical analysis aimed at
developing the information that will be used to assess these benefits and costs. The analysis
in the present report will determine how the health impacts and volumes of soil to be
remediated vary as functions of the possible cleanup level. (The cleanup standard will specify
one specific dose or risk value, and this is termed "the cleanup level" in this report.) As such,
this technical analytical process will require answers to the following critical questions:
• At typical or representative sites, what are the radiation doses and risks to an
individual resulting from exposure, via all environmental pathways, to unit
concentrations of radionuclides in site soil—i.e., what is the risk or dose per
picocurie/gram (pCi/g) for each radionuclide present?
• Conversely, what radionuclide soil concentrations, in units of pCi/g, would
have to be achieved in order to meet various possible individual dose or risk
cleanup levels?
• At typical or representative sites, how much soil contains radioactivity in
excess of any given radionuclide soil concentration (RSC)? That is, what
volumes of soil would require remediation ^.g., excavation and/or processing)
to ensure that RSCs on-site after cleanup meets various possible cleanup
levels?
• How many potential radiogenic cancers, and cancer deaths, would be averted
by remediating the soil to RSCs corresponding to various individual risk
levels? (These are population rather than individual effects.)
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How many radiogenic health effects might eventually occur among remediation
workers and the general public because of the remediation process itself?
(Non-radiogenic health effects are considered elsewhere, not in the present
report.)
Reference Sites Clearly it is not possible, in this rulemaking process, to answer these
questions accurately for each of the thousands of sites in the U.S. known to be contaminated,
nor is it necessary to do so.
EPA is performing, rather, a detailed analysis of the remediation of a small set of relatively
simple but quasi-realistic "reference" sites that are intended to represent the range of
conditions found among real contaminated sites. Each reference site was created partially, but
not completely, out of information available on one or more real sites. Thus theset of
reference sites, taken as a whole, is intended to cover the universe of actual sites, and the
potential current- and future-exposure scenarios, in such a manner that the assessment of
remediation costs and benefits for the reference sites is supportive of the cleanup rulemaking.
In creating the reference sites, EPA has had to rely extensively on available data on real sites
that it, and other Federal agencies, have collected. There is much uncertainty about the nature
and extent of contamination at many real contaminated sites, however, and on their
hydrogeological and meteorological characteristics, which influence the mobility and
dispersion of radionuclides. Since some of the site characterization information required for
the present analysis simply does not exist for the real sites, it has been necessary to generate it
by extrapolation of available data and by other indirect means described in Chapter 4.
In the creation of reference sites, moreover, certain attributes of the real sites upon which they
are partially based have intentionally been simplified. In the analysis of Reference Site I, for
example, which is intended to resemble the Hanford Reservation, to some extent, no account
was taken of the tank farms and their immediate vicinities. It is assumed, based on reports of
the Department of Energy (DOE), that so widely and highly contaminated areas are not likely
to be cleaned up and released for public use in the foreseeable future; while of great
significance to EPA's radioactive waste disposal rule, also currently under development, the
tank farms are felt to lie outside the scope of the site cleanup regulation. For the purposes of
the present analysis, it is therefore simply proposed that the major waste disposal areas will be
stabilized and/or remediated in an adequately protective manner.
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Finally, this analysis greatly simplifies the determination of future land use scenarios and
population densities. In particular, simple, reasonable, conservative assumptions on the future
utilization of the sites following cleanup have been made.
It must therefore be emphasized that the parameters defining a reference site doiot fully
coincide with those that would characterize the real site(s) upon which it is based. It would be
misleading to assert that any reference site provides an accurate and complete description of
the corresponding real site(s). In particular, predicted health impacts and volumes of soil to
be remediated refer only to the reference site itself, and must not be used in an attempt to
predict future impacts at the vastly more complex real site upon which it is based.
Modeling Individual Risk Estimates of doses and risks to individuals and populations depend
on the pathway modeling tools and assumptions used in their calculation, including possible
exposure scenarios. Based on consideration of current land use and demographics near some
of the sites subject to this rule, two specific scenarios have been considered in the assessment
of individual risks at the reference sites: For theRural Residential scenario, people living on-
site consume some vegetables, milk, meat, and fish produced there. For the
Commercial/Industrial scenario, workers spend 2000 hours per year on-site and eat nothing
produced there.
EPA has evaluated the suitability of more than two dozen multimedia pathway models and
computer codes for analysis of the reference sites. Guided by this evaluation, EPA has
employed primarily one of these models—RESRAD 5.19—to estimate individual risk factors.
(A "risk factor" is the lifetime risk to individuals resulting from exposure to a unit
concentration of a radionuclide in soil (i.e., lifetime risk per pCi/g). Once a risk factor for a
radionuclide is determined for a site, the radionuclide soil concentration corresponding to a
given risk-based cleanup level can be derived by dividing the cleanup level by the risk
factor—i.e., pCi/g = (risk)/(risk per pCi/g). Because risk factors depend on site-specific
parameters, such as the depth of the aquifer and the distribution coefficients QQ, risk factors
must be calculated separately for each reference site.)
To assist in assessing the reliability of such estimates, EPA has compared the results from
RESRAD with those from two other models, an updated version of RAGS/HHEM Part B
[Risk Assessment Guidance for Superfund - Human Health Evaluation Manual (Part B)]
(EPA 9la) and PRESTO-CPG, in the calculation of risks to individuals at a simple "generic"
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test site; has carried out sensitivity analyses on the generic test site with RESRAD to
determine how the results change when the values of certain critical parameters are varied;
and has performed a preliminary probabilistic Monte Carlo analysis on the generic test site
using updated RAGS/HHEM equations to estimate the degree of uncertainty in the results. In
addition, the Agency has performed an extensive qualitative uncertainty analysis on the
parameter values used in the modeling of the reference sites, as will be discussed in
Chapter 6.
Estimating Numbers of Health Effects in Populations EPA has quantified the radiogenic
health impacts in populations that result from achieving alternative individual risk
levels—i.e., the numbers of cancers and cancer fatalities averted. The Agency has developed
a simple, high-end population health effects model, built on equations similar to those of the
updated RAGS/HHEM Part B model, for application to the reference sites.
Several land-use scenarios are assumed for the modeling of health effects in populations at the
reference sites, and these fall into two general classes: Between 10 and 300 people per square
kilometer inhabit an Agricultural site, and all the food they grow is consumed locally (that is,
on-site and by near-by communities). The population density ranges from 10/krnto more
than 1,000/km2 at a Suburban site, and no food is produced locally. The calculations track
population doses and adverse health effects averted over periods of 100, 1000, and 10,000
years.
Estimating Volumes Of Soil To Be Remediated An important determinant of the costs of
cleaning up a site to various possible risk levels is the volumes of soil to be remediated in the
process. The present analysis estimates such cleanup volumes for each reference site by
combining two kinds of information: risk factors (risk per pCi/g) obtained from site-specific
modeling, and pre-cleanup soil volumera. contaminant concentration relationships derived
from published reports on the corresponding real site(s).
A challenging aspect of this analysis has been the extraction of soil volumera. contaminant
concentration information from the available site documents, especially when multiple
radionuclides are present. Methods developed for this purpose are described in detail in
Chapter 4.
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Implementation Once a cleanup level has been established, it is necessary to translate it into
quantities that can guide the remediation of real sites. Generic tables of limiting soil
concentrations and computer codes for site-specific modeling are two forms that such
guidance might take, and these will be available at the time that the final rule is published.
At any site undergoing remediation, compliance with the cleanup level must be demonstrated,
in a scientifically rigorous and legally defensible manner, with appropriate radiation detection
instruments and techniques. Various kinds of field and laboratory equipment differ in
inherent sensitivity and specificity, and these differences are affected by the presence of
background radioactivity from naturally occurring and manmade radionuclides. The technical
analysis will evaluate issues related to radiation detection capability, to the relationship
between measurement and background radioactivity, and to the feasibility of detecting site
contamination over background.
As implementation guidance, EPA will provide site owners/operators with procedure manuals
for conducting field surveys and for collecting samples for laboratory analysis. EPA is
cooperating with the U.S. Department of Energy (DOE), the U.S. Department of Defense
(DOD), and the NRC in the development of a Multi Agency Radiological Site Inspection
Manual (MARSIM) that describes standard field and sampling procedures. EPA will also
provide guidance on standard operating procedures and quality-assurance guidelines for
radiochemical analyses.
Scope of EPA's Cleanup Standards Regulatory Development Technical Analysis.
And Overview of This Report
EPA is conducting its technical analysis in five separate but related areas to support the
development of cleanup standards for sites contaminated with radioactivity. These areas
address:
(1) Soils;
(2) Aquifers; and
(3) Structures.
The current report is limited in scope to analyses supporting the development oJsoil cleanup
standards (i.e., item (1) above). It is important to clarify that this report is concerned with
Review Draft - 9/26/94 1-6 Do Not Cite Or Quote
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residual levels of radioactivity in the soil following cleanup. The report deals with the
radioactivity in waste storage areas and burial grounds only to the extent that they have
contaminated the surrounding soils. That is, it is limited to the analysis of areas, away from
permanent waste disposal areas, where the soil has been contaminated as a result of spills,
local fallout, overflow contamination, runoff from nearby sources of radioactive waste and/or
windblown depositions.
The five questions posed early in this Introduction suggest the types of information needed to
assess the potential doses and risks to individuals, numbers of health effects, and costs as a
function of various alternative cleanup levels. The technical analysis being undertaken to
answer those five questions is summarized below, and the headings correspond to the
chapters of this technical report. Figure I is a flow diagram indicating the steps in the process,
and the "Item" numbers in the text below correspond to the Figure I block numbers. Items
noted with an asterisk (*) are not within the scope of this report, but will be addressed in the
Background Information Document (BID) or Regulatory Impact Analysis (RIA) supporting
the rulemaking.
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Figure I. Flow of Work
CLEANUP
LEVEL
SELECTION
IMPLEMENTATION
GUIDANCE
13
Site-specific
implementation
model
14
pCi/g
tables
15
SOPs,
MARSIM
QA,etc.
11
Economic,
non-rad., &
ecological
impacts;
other
considerations
-------
Chapter Description1
1. Magnitude of the Cleanup Problem—What's out there1
• Determine nature and extent of the site contamination problem.
• Compile and review existing data characterizing real contaminated sites. (Item 1)
• Establish a scheme for partitioning the universe of real contaminated sites into
broad functional categories. (Item 2)
• Estimate the number of real sites in each category. (Item 6)
• Estimate the total volume of soil that may fall within the scope of this rule.
2. Environmental Pathway Models—selecting the risk assessment tools (Item 3)
• Characterize the exposure pathways; Tabulate default parameters, distributions,
and assumptions for: Rural Residential and Commercial/Industrial land-use
scenarios
• Develop pathway model selection criteria.
• Test and compare available models; select multi-media pathway model(s) to
estimate doses and risks to individuals at the reference sites.
• Develop a simple, high end population model for application to the reference sites.
1 Items noted with an asterisk (*) are not within the scope of this report, but will be addressed in the
Background Information Document (BID) or Regulatory Impact Analysis (RIA) supporting the rule-
making.
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Chanter Description
3. Assessment of Modeling Parameters and Capabilities — Developing and testing the risk
assessment tools (Item 4)
• Construct a generic test site for testing the pathway model(s) for individual and
population doses and risks. The site is "generic" in the sense that it employs base-
case parameters selected to provide reasonable (but conservative) estimates.
• With RESRAD, generate tables of risk factors for the generic test site.
(Item 7)
• Compare the analysis of the generic test site using RESRAD with analyses by
using other models, RAGS/HHEM and PRESTO-CPG. Assess the sensitive
pathways and parameters, and compare the degree of conservatism of the three.
• Perform a sensitivity analysis of RESRAD using the generic test site. Parameters
to be varied are radionuclide, site dimensions, thickness of layer of contamination,
depth of aquifer, infiltration rate, and distribution coefficient
Perform a preliminary Monte Carlo uncertainty analysis using the updated
RAGS/HHEM Part B model.
The generic test site may be employed later in generating soil concentration limit
tables for use in implementation of the rule.
4. Creation of Reference Sites—Preparation for analysis of health effects and volumes of
soil undergoing remediation
• Drawing from the data characterizing the source, environmental, and demographic
characteristics of actual sites (Item 1), and the site categorization scheme (Item 2),
develop a limited number of reference sites that, as a set, together represent the
universe of real sites in all categories (Item 5). Descriptions of the reference sites
include
typical radiological source terms, hydrogeology, etc.
volumes of soil at different levels of contamination
• Estimate the number of sites in each category—i.e., the number of sites to be
represented by each reference site. (Item 6)
• Develop a site-weighting system, so that results from the analysis of the set of
reference sites can be extrapolated to the universe of all real contaminated sites.
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Chapter Description
5. Analysis of Reference Sites—Analysis of health effects and support for analysis of
volumes of soil undergoing remediation
• Develop risk factors for each of the reference sites. (Item 8)
• From site specific information, develop soil volumera. contamination
concentration curves for each reference site (indicating the volumes of soil
contaminated to various degrees of radioactivity, in pCi/g, at the site); extrapolate
to lower soil concentrations, if necessary. (Item 9)
• For each reference site determine, as a function of individual risk (or dose) level,
the volume of soil requiring remediation (Item 10).
• For each reference site determine, as a function of individual risk (or dose) level,
the number of potential radiogenic cancers averted among the general public, and
the number of potential radiogenic cancers that would be induced among
remediation workers. (Non-radiogenic health effects among remediation workers
and others are considered elsewhere, not in this Report).
• Making use of the above information, and of other input (Item 11)*, a cleanup
level (risk or dose level) will be selected. (Item 12)*
Uncertainty Analysis—How reliable are the results of the analysis of the reference
sites?
Implementation—Selecting final soil concentrations and demonstrating compliance
• Translate cleanup level (dose or risk) into something measurable in the field or
laboratory (Items 13, 14)
• Provide means of demonstrating that field and laboratory measurements are
appropriately and being performed properly ^.g., MARSIM) (Item 15).
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1. Magnitude of the Cleanup Problem
This section describes the magnitude of the overall cleanup problem. It characterizes the
general types and numbers of sites contaminated with radioactive materials as well as the
estimated volumes of contaminated soil. It surveys sites that include the U.S. Department of
Energy (DOE) weapons complex and research facilities, the U.S. Department of Defense
(DOD) installations and bases, sites licensed by the U.S. Nuclear Regulatory Commission
(NRC) and its Agreement States, other sites controlled by States, sites under the authority of
other Federal agencies, and EPA Superfund National Priorities List (NPL) sites. It does not,
however, include all "potential" sites where radioactive materials are known to have been
used in the past or where they are currently used, unless it is also known that there have been
accidental or intentional releases at such sites which have allowed soils, aquifers, surface
waters, and/or structures to become contaminated.
1.1 NUMBERS OF SITES
A critical issue in determining the number of contaminated sites is the definition of site. For
example, some programs use the term site to refer to specific localized areas of contamination
at a facility, while other programs equate site with an entire facility. These terms are often
used inconsistently, and overlap in meaning, even within the same program or agency. Other
commonly used terms include release., facility., installation., base., area of concern, study area,
operable unit., waste area grouping, solid waste management unit, and waste unit.
For the purpose of counting sites, this report has adopted the following definition for
identifying sites that are known to be contaminated with radioactivity in the United States and
that may fall within the scope of the cleanup rulemaking:
A "site" is any installation, facility, or discrete, physically separate parcel of land, or
any building or structure, or any body of ground water or surface water, that is known
to be contaminated with radionuclides in concentrations greater than those naturally
occurring. When a portion of such an entity is contaminated, the entire entity is
considered a "site." For example, the Hanford Reservation, which has many
contaminated buildings, discrete release sites, and ground water contamination, is
considered a single "site."
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Tables 1-1 and 1-2 present an overview of the number of sites known to be contaminated with
radioactivity, indicating a total number of about 5,000 sites. Included are sites that are: on
EPA's National Priorities List (NPL); under the authority of various Federal agencies
(predominantly DOE and DOD); licensed by the NRC and NRC Agreement States; and under
the control of individual states. The majority of these sites are two types of NRC/Agreement
State licensees: 3,471 research and development facilities and 930 sealed source
manufacturers, according to recent NRC estimates (NRC 94). The largest and most severely
contaminated sites are those of the DOE weapon production complex. It should be clear from
the introduction of this report that the proposed rule does not apply to all of the sites counted
in Tables 1-1 and 1-2.
Table 1-1 INVENTORY BY AGENCY OF SITES THAT ARE KNOWN TO BE
CONTAMINATED WITH RADIOACTIVITY: TOTALS
AGENCY
Department of Energy
Department of Defense
Other Federal Agencies
Federal Total
NPL Non-Federal
NRC/Agreement States
Other State Sites
TOTAL
DEPARTMENT
Army
Navy /Marine
Air Force
Air National Guard
NUMBER OF SITES
96
68
9
69
1
2
245
21
4676
-
4942
NUMBER OF NPL SITES
19(25*)
10
4
14
1
1
49(55*)
21
-
-
70(76*)
! Including additional areas listed under NPL.
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Table 1-2 INVENTORY OF SITES THAT ARE KNOWN TO BE
CONTAMINATED WITH RADIOACTIVITY
AGENCY
FEDERAL SITES
DOE SITES: Major Sites
National Laboratories
Other Sites
DOD SITES: Major Site
Other Sites
OTHER FEDERAL SITES:
NON-FEDERAL SITES
NPL SITES:
NRC/AGREEMENT STATES SITES:
OTHER STATE SITES:
TOTAL
SITE NAME
Fernald ' |
Hanford 2 1
INEL3t
Mound " t
Nevada Test Site5
Oak Ridge Reservation6 1
Paducah ' f
Pantex 8 1
Portsmouth '
Rocky Flats 10 1
Savannah River11 f
Weldon Spring12!
Argonne 13
Brookhaven14 1
Fermi 15
Lawrence Berkeley 16
Lawrence Livermore " |
Los Alamos ls
Sandia19
FUSRAP Sites20
UMTRAP Sites21
Other DOE Sites22
Aberdeen Proving Ground23
Sites with Burial Areas24
Sites with Accident Contamination25
Sites with DU Contamination26
Other DoD Sites27
USDA Fremont National Forest28 |p
GSA Watertown Arsenal29
Municipal Landfills 30
Radium Sites31
Other Non-Federal NPL Sites32
Nuclear Power Plants33
Test and Research Reactors34
Other Fuel Cycle Facilities35
Rare Earth Extraction Facilities36
Byproduct Material Facilities37
.38
SITE/ LOCATION
COUNT
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
30
14
33
1
79
1
15
51
1
1
3
7
11
125
63
65
22
4401
-
4942
t - NPL Listed |P - NPL Proposed
Footnotes 1-38 in this table can be found in Appendix A of this Technical Support Document.
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1.2 MAJOR CLEANUP PROGRAMS
It simplifies the process of determining the magnitude of the cleanup problem to group
contaminated sites according to their responsible agency or remediation program. For many
of them, cleanup programs have already been established. The following is an overview of
the major cleanup programs in the United States. Since it is broadest in scope, the overview
begins with EPA's Superfund Program.
1.2.1 Superfund Program
In 1980, the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) launched the Superfund Program to clean up hazardous waste sites that threaten
human health or the environment. To implement CERCLA, the EPA also promulgated the
revised National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR
part 300, pursuant to CERCLA section 105 and Executive Order 12316. The NCP sets forth
the procedures and guidelines needed to respond under CERCLA to releases and threatened
releases of hazardous substances, pollutants, or contaminants. The Superfund Amendments
and Reauthorization Act of 1986 (SARA) was enacted on October 17, 1986.
CERCLA section 105(a)(8)(A) requires that the NCP include "criteria for determining
priorities among releases or threatened releases throughout the United States for the purpose
of taking remedial action." Three processes for listing sites on the NPL are included in the
NCP: (1) Under 40 CFR 300.425(c)(l), a site may be included on the NPL if it scores 28.50
or greater on the Hazard Ranking System (HRS), which EPA promulgated as Appendix A of
40 CFR part 300 (This is the most common route by which federal sites are placed on the
NPL); (2) 40 CFR 300.425(c)(2) requires that, to the extent practicable, the NPL include
within the 100 highest priorities, one site designated by each State representing the greatest
danger to public health, welfare, or the environment among known sites in the State (i.e., each
State may designate a single site as its top priority, regardless of the HRS score); (3) 40 CFR
300.425(c)(3) allows certain sites to be listed whether or not they score above 28.50, if they
meet all of the following conditions:
• The Agency for Toxic Substances and Disease Registry (ATSDR) of the U.S.
Public Health Service has issued a health advisory that recommends
dissociation of individuals from the release.
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• EPA determines that the release poses a significant threat to public health.
• EPA anticipates that it will be more cost-effective to use its remedial authority
(available only at NPL sites) than to use its removal authority to respond to the
release.
• By EPA policy, the Superfund Program does not enter NRC - Licensed Sites
onto the NPL (48 CFR 40661, Sept. 8, 1993)
EPA maintains a database (called CERCLIS) of all reported potentially hazardous releases to
the environment. Of over 37,000 entries in CERCLIS, 1231 are listed NPL sites, and 76 of
these are radioactively contaminated. Many of the 76 radiation sites, however, were actually
listed because of their chemically-hazardous contamination rather than their radioactivity
contamination.
The primary purpose of the NPL is to identify, for States and the public, facilities, sites, or
releases that warrant remedial actions. The NPL also serves to notify the public of sites that
EPA believes warrant further investigation.
1.2.2 Formerly Utilized Sites Remedial Action Program (TUSRAP^
The FUSRAP program was initiated in 1974 by the Atomic Energy Commission (AEC), the
predecessor of the U.S. Department of Energy. The purpose of this program is to identify,
evaluate, and if necessary, decontaminate (to current applicable standards) sites, or apply
controls at sites, that were previously used by the AEC or its predecessor, the Manhattan
Engineering District (MED). The MED and the AEC conducted several programs during the
1940s and 1950s that involved research, processing, and production of uranium and thorium,
and the storage of residues. The facilities where this work was accomplished were
decommissioned and decontaminated to meet the health and safety guidelines in use at that
time. However, due to the emergence of more stringent health and safety standards, it has
become necessary to reassess the need for, and to conduct, remedial action at many of these
sites. Preliminary information on the radiological conditions at most of the sites is known
from radiological surveys or characterization activities conducted at the sites. Also, from the
more recent radiological surveys, it has become known that several private properties (called
"vicinity properties") adjacent to many of these sites are contaminated from the processing
operations carried out for MED/AEC and require remediation.
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Currently, there are 46 sites in 14 states included in FUSRAP, with most of these sites
requiring some form of remedial action. To date, fourteen sites have completed remedial
actions. Four other sites are on the NPL for remediation.
The FUSRAP program objectives include the disposal or stabilization of the waste and
certification of the sites remediated for use without radiological restrictions. All work
accomplished under the program must be in accordance with all applicable Federal, State, and
local laws. Remediation action at the sites must satisfy the requirements of the National
Environmental Policy Act (NEPA) and CERCLA, as amended by SARA.
1.2.3 Uranium Mill Tailings Remedial Action Program OJMTRAP^
The mission of the UMTRAP is explicitly stated and directed in the Uranium Mill Tailings
Radiation Control Act (UMTRCA) of 1978 (Public Law 95-604, 42 USC 7901). Title I of the
Act authorizes DOE to undertake remedial actions at designated inactive uranium processing
sites and associated "vicinity properties" containing uranium mill tailings and other residual
radioactive materials derived from the processing site. The purpose of the remedial actions is
to stabilize and control uranium mill tailing piles and other residual radioactive materials in a
safe and environmentally sound manner to minimize radiation health hazards to the public.
Currently, there are 24 designated inactive uranium processing sites in the Program.
Remediation work has been completed at ten of these sites. There are other uranium mill
tailing sites, subject to Title II of the UMTRCA, that are licensed by the Nuclear Regulatory
Commission and Agreement States.
Remedial actions undertaken by DOE pursuant to the Act are to be accomplished in
cooperation with the affected states and Indian tribes within whose boundaries designated
uranium processing sites are located, and with the concurrence of the Nuclear Regulatory
Commission. Such remedial actions are to be performed in accordance with the standards
promulgated by the EPA (40 CFR Part 192) and with applicable Federal and state laws.
Because these sites are covered under the UMTRCA, they will not be subject to EPA's
cleanup rule currently under development.
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1.2.4 Defense Environmental Restoration Program (DERP)
DERP was established in 1984 to promote and coordinate efforts for the evaluation and
cleanup of contamination at DOD installations. The program includes the Installation
Restoration Program (IRP), where potential contamination at DOD installations and formerly
owned or used properties is investigated, and as necessary, site cleanups are conducted.
SARA provides authority for the Secretary of Defense to conduct the DERP Program in
consultation with the EPA. In so doing, the Secretary of Defense conducts the program
within the overall framework of SARA and CERCLA.
The IRP Program conforms to the requirements of the NCP. EPA guidelines are applied in
conducting the investigations and remedial actions within the program. The order in which
DOD conducts IRP activities is based on a policy assigning the highest priorities to sites that
represent the greatest potential public health and environmental hazards.
The Base Closure and Realignment Acts of 1988, 1991, and 1993 identified over 100 military
bases for closure. The total number of base realignments and closures (commonly called
BRAC's) may eventually exceed that number. It is not known at present how many of these
bases are contaminated with radioactivity. Considerable investigation, and in certain cases
remediation, may be required before properties at the closed bases can be transferred from
DOD or used for other purposes (DOD 92).
1.2.5 Site Decommissioning Management Plan (SDMP)
The former Atomic Energy Commission (AEC), and the now Nuclear Regulatory
Commission (NRC) have terminated approximately 33,000 material licenses during the past
four decades. Most of these terminated material licensee sites contain no significant amounts
of radioactive contamination that would require remedial actions. As part of the license
termination process, licensees are required to decontaminate and decommission their facilities
by reducing or removing residual radioactivity in land, groundwater, buildings, and
equipment to criteria levels that allow the property to be released for unrestricted use. Sites
are inspected by NRC inspectors to verify the absence of excess residual contamination
before a license is terminated.
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NRC decommissioning requirements and practices have been repeatedly and critically
reviewed by the General Accounting Office (GAO). A December 21, 1989 Commission
briefing, concerning strategies for decommissioning licensed sites, resulted in the issuance of
a Staff Requirements Memorandum dated January 31, 1990, which directed the staff to
develop a detailed list of contaminated, currently licensed, sites. The staff responded by
creating the SDMP, which was forwarded to the Commission in March 1990.
At present, 47 sites with radioactive contamination are included in the Program. Many of
these sites have either been closed down or are in the process of being closed down. The sites
have buildings, former waste disposal areas, piles of tailings, groundwater, and soil
contaminated with low levels of uranium and/or thorium (source material) and/or other
radionuclides.
A combination of health and safety and program management issues is used as the basis to
prioritize NRC efforts to review contaminated sites. The first priority is public health and
safety. Although known contamination at SDMP sites is generally stabilized or under control,
and not currently causing significant adverse effects on public health and safety, all sites will
require remedial cleanup efforts before the licenses can be terminated and the sites released
for unrestricted use (NRC 92a).
1.3 SITES GROUPED ACCORDING TO RESPONSIBLE AGENCIES/PROGRAMS
Some contaminated sites have already been described in the context of existing federal
cleanup programs. This section expands the discussion to cover all known sites contaminated
with radioactivity, again by responsible agency.
In Tables 1-1 and 1-2, contaminated sites have been put into four general groups: Federal
facility sites; NRC licensees; non-Federal NPL sites; and sites under State control.
(Additional information on sites can be found in Appendix A of this report.)
1.3.1 Federal Facility Sites
Federal sites are owned or operated by, or are under the authority of Federal agencies.
Included are military bases, national research laboratories, weapons complexes, and
radioactive materials production sites. The largest sites known to be contaminated are DOE
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sites, a number of which are listed on the NPL. At many non-DOE Federal sites, the use of
radioactive materials are licensed by NRC. As of September 1992, Federal agencies held 299
NRC licenses for non-sealed sources. The number of sites where radioactive material is
present is substantially higher, however, since the Air Force, Navy, and the Department of
Agriculture each have a single broad, multi-site, multi-regional research and development
NRC materials license. In addition, other federal agencies possess or control some
radioactive materials that do not require NRC licenses. These include some radioactive
material related to nuclear weapons, nuclear reactors, and naturally occurring radioactive
material.
Department of Energy
DOE is responsible for cleaning up 96 contaminated sites in 34 states and territories
(DOE 94a). These sites include major weapons facilities, nuclear material production plants,
national laboratories, FUSRAP sites, UMTRAP sites, and other surplus sites. Contamination
ranges from small, slightly contaminated laboratory rooms to large, complex, highly
contaminated processing plants, as well as surrounding contaminated lands. In addition to
sites that are government owned, DOE has responsibility for some sites that were formerly
used in government operations or for the benefit of the government. For example, the
Maywood site was an AEC-licensed commercial facility used to process, manufacture, and
distribute radioactive materials, and large quantities of radioactive wastes were buried onsite.
Active sites are under the DOE Waste Operations Program, and inactive or surplus sites are
under the DOE Environmental Restoration Program. Waste management includes treatment,
storage, and disposal of high-level, low-level, transuranic, chemically hazardous, mixed, and
solid sanitary wastes. The Environmental Restoration Program includes remedial actions and
decontamination and decommissioning. Remedial actions are concerned primarily with all
aspects of the assessment and cleanup of inactive sites. Decontamination and
decommissioning activities focus primarily on the safe caretaking of surplus nuclear facilities
until they are decontaminated for reuse or demolished and completely removed. Many
problems addressed in environmental restoration are the result of past waste management
practices that were considered acceptable at the time, but do not meet today's more stringent
standards for protection of human health and the environment. DOE's contaminated sites
include uranium mines and mills, nuclear materials production facilities, weapons production
and testing sites, national laboratories, and waste disposal sites.
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Most of the sites in the DOE ER Program are large, complex, and multi-functional facilities.
Because of their size and complexity, the DOE sites are subdivided into smaller, more
manageable units based primarily on geographic location and function. These major facilities
represent most of the soil volume that falls within the scope of EPA's proposed radiation site
cleanup regulations.
DOE has 19 large and multi-functional facilities, including nuclear material, fuel fabrication,
and weapons assembly plants, and national laboratories. Radioactive contamination is often
widespread at these complexes. At the Hanford Site, for example, approximately 1,500 waste
units have been identified as potentially requiring some degree of remediation. Most of these
units were contaminated by onsite storage or soil disposal of low-level radioactive and
chemical waste, resulting primarily from the production and chemical processing of
plutonium. The waste units, ranging from a few square feet to 1,800 acres in area, have been
grouped into 78 operable units. These units have been further organized into four large
aggregate areas based primarily on their geographic location. Similar situations occur at other
large DOE facilities.
Four of the 19 major DOE sites were devoted primarily to the production of nuclear fuels:
Fernald, Portsmouth, Paducah, and the K-25 Plant at the Oak Ridge Reservation. Cleanup
recently began at Fernald under the Fernald Environmental Management Project (FEMP).
This plant was used to process uranium from 1953 to 1989. Contaminated materials located
at FEMP in 1990 included 122,100 drum equivalents of low-level waste, 1,100 metric tons
(MT) of thorium compounds, and 8,800 MT of radium-bearing residues. Contaminated soils
and groundwater are also present.
DOE's weapons production and testing sites handle nuclear weapons from the design and
testing phases to the full production phase. These test sites all have localized subsurface
contamination, and some have surface contamination with hazardous and mixed wastes
related to drilling mud disposal pits.
Many DOE facilities are devoted to basic physical and scientific research. These facilities
include Fermi National Accelerator Laboratory, Princeton Plasma Physics Laboratory, and
Stanford Linear Accelerator Center.
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There are many waste burial repositories within the DOE complex. They include major waste
disposal locations such as those at Hanford, Oak Ridge, Savannah River, Idaho National
Engineering Laboratory, Los Alamos National Laboratory, Fernald, and the Nevada Test Site.
Smaller quantities of wastes are also buried at the Ames Laboratory, Brookhaven National
Laboratory, Sandia National Laboratory-Albuquerque, Lawrence Livermore National
Laboratory, Paducah, and Portsmouth. Designated waste repositories are not considered sites,
unless they have leaks or otherwise do not meet current standards.
Lastly, there are a small number of miscellaneous DOE facilities with specific functions,
including the West Valley Demonstration Project, where fuel reprocessing was conducted and
a variety of radioactive wastes are stored.
Department of Defense
According to DOD's Installation Restoration Program (IRP), there are 1,877 installations of
varying sizes with over 17,500 potential hazardous waste releases (Baca 92). Only a few of
these are currently known to have radioactivity contamination. When these sites become
more fully characterized, the number of known sites will most likely change. DOD sites vary
widely in function and size. They include hospitals, laboratories, proving grounds, bombing
and gunnery practice ranges, missile launch sites, weapons manufacturing and storage
facilities, and reactors. Most radioactive material handled at military sites results from
research and development, testing of military munitions, and testing and operation of military
reactors. DOD sites may contain small enclosed radiation sources such as radium and tritium
instruments, larger sources such as research reactors contaminated with fission products, and
dispersed sources such as laboratory waste storage areas and test ranges contaminated with
depleted uranium.
Depleted uranium shells and small munitions have been fired at 12 testing ranges. In
addition, there are four other sites involved in processing and storing depleted uranium.
DOD nuclear power reactors produce electricity and heat, and test and research reactors were
used in nuclear weapons development and to perform other physical and medical research.
Six power reactors were used to service remote installations and have been dismantled or shut
down. Fifteen test and research reactors have been dismantled or shut down. Residual
radioactivity at the non-operating reactors consists primarily of activation products.
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Radioactive wastes from nuclear ships include low-level radioactive waste, mixed low-level
radioactive and chemically hazardous waste, defueled reactor compartments, and spent naval
reactor fuel. These radioactive wastes are either disposed of at NRC licensed commercial
disposal sites or buried in DOE-owned disposal facilities.
The national defense stockpile (a reserve of strategic ores for the production of fuel and
weapons material) contains about 3,000 tons of thorium nitrate and about 16,000 tons of
zirconium-bearing ore containing 0.3 to 0.4% uranium and thorium. The primary cleanup
concerns are soil and equipment contaminated with radium, uranium, and thorium.
1.3.2 NRC Licensees
The NRC and its Agreement States currently manage about 22,000 licenses for the production
and handling of radioactive materials (NRC 93). (For the purpose of this report, EPA uses
NRC's site count estimates.) About one third of these are NRC licensees, while the remainder
are licensed by Agreement States under Section 274 of the AEA. Licensees include nuclear
power plants (licensed only by NRC) universities, medical institutions, radioactive source
manufacturers, and companies that use radioisotopes for industrial purposes.
NRC's Generic Environmental Impact Statement (GEIS) indicates that about 75 percent of
NRC's 7,000 licensees use either sealed radioactive sources or small amounts of short-lived
radioactive materials, this percentage is applicable to the Agreement State licensees, as well.
Activities at these facilities are not likely to result in significant radioactive contamination that
would need to be cleaned up, because the radionuclides generally remain contained in sealed
encasements and cause little (if any) contamination, and/or because the radionuclides decay
rapidly to non-radioactive elements, often in hours or days. A small number of licensees
(e.g., radioactive source manufacturers, radiopharmaceutical producers, and radioactive ore
processors) conduct operations that could result in substantial radioactive contamination in a
facility.
NRC has issued thousands of byproduct material licenses. The byproduct material at sites
subject to this rule are materials made radioactive by exposure to radiation during the process
of producing or utilizing enriched uranium or plutonium. These licensees are involved in a
variety of activities, including research, materials testing, chemical production, drug
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research, clinical testing, mineral exploration and processing, and basic and applied research
in various scientific disciplines. In the GEIS, NRC estimated site counts only for two types of
byproduct material licensees, sealed source manufacturers (930) and research and
development facilities (3471). These NRC counts of byproduct material licenses include
those administered by Agreement States.
By the end of 1992, there were 109 nuclear power reactors operating in the United States.
(Though several reactors may operate at a single power generating station, for the purposes of
this report, each reactor is considered to be a separate site). There are 72 pressurized water
reactors and 37 boiling water reactors. Since 1964, a total of 16 nuclear power plants have
been taken out of operations.
There are 47 nuclear reactors (with operating licenses) that are used for research and testing
purposes. In addition, the operating licenses of 8 facilities have been changed to possession
only and 10 other reactors are currently planning or undergoing decommissioning.
In addition to reactors, there are various kinds of other facilities that make up what is called
the uranium fuel cycle. They include Uranium Ore Milling Sites, Uranium Hexafluoride
Production Plants, Fuel Fabrication Plants, and Dry Spent Fuel Storage Facilities.
A rare earth or metals ore processor is a facility (not part of the fuel cycle), that refines raw
ore materials to recover rare metals such as tantalum and niobium. These ores may contain
appreciable concentrations of naturally occuring radionuclides, such as uranium and thorium,
which may be concentrated in the waste tailings from the refining process. There are 22 rare
earth extraction facilities in the U.S.
1.3.3 Non-Federal National Priorities List TNPU Sites
There are 75 final and 1 proposed NPL sites with radioactive contamination. Of these, 25 are
DOE sites, 29 are DOD sites, 1 is a Department of Agriculture site, and 21 are non-Federal
sites. The EPA has assumed lead responsibility for the 21 non-Federal sites. Although these
sites are on the NPL, many were put on the list for hazardous chemical contamination rather
than their radioactive contamination. Additional information concerning these sites can be
found in EPA's draft report, Known Radioactively Contaminated Sites in the United States -
Draft.
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1.3.4 Sites Under State Control
While some states have NRC Agreement State authority over AEA materials, all states may
exercise control over radionuclides not covered by the AEA, such as naturally occurring and
accelerator-produced radioactive materials (NARM). These state sites and facilities are
included for the sake of completeness in this description of the universe of sites containing or
contaminated with radioactive materials. It is important that they are included in this
discussion because they represent potentially a very large volume of soil containing elevated
levels of radionuclides.
Sites where naturally occurring radioactive materials (NORM) may possibly be concentrated
include mines, mineral extraction sites, sites involved with oil and gas drilling, and
geothermal energy production sites. NORM is also often found in ash from coal burning
power plants, and in abrasive blasting materials from coal slags.
According to the Conference of Radiation Control Program Directors' (CRCPD) statistics,
there are approximately 9,000 state controlled sites in the U.S. It is not known what fraction
of these are actually contaminated with radioactive material.
1.4 FUNCTIONAL CATEGORIES
To model the universe of radioactively contaminated sites, and estimate volumes of
contaminated soil resulting from cleanup, it is necessary to create a set of quasi-realistic
reference sites that represent the universe of sites. To facilitate this process a site
categorization scheme was developed which groups sites and facilities into functional
categories. Working together with representatives of DOE, DOD, and NRC, EPA assembled
the functional categorization scheme. Eighteen categories were constructed to cover the
range of sites contaminated with radioactive materials. These 18 categories are generally
consistent with various types of DOE, DOD, and NRC-regulated facilities described in
Section 1.3. It is intended that the complete set of reference sites, corresponding to each
category, will represent the full range of actual sites that fall within the scope of the rule. The
functional categories and reference sites are fully described in Chapter 4 of this report.
1.5 VOLUME OF SOIL CONTAMINATED WITH RADIOACTIVITY
The volume of soil contaminated with radioactivity is not known with any degree of certainty
and will not be known until cleanup criteria are defined and the sites are remediated.
Nevertheless, based on preliminary information provided in DOE's Integrated Data Base
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(DOE 94b), NRC's Generic Environmental Impact Statement (GEIS, NRC 94), and ongoing
EPA studies (EPA 93b), it is estimated that approximately 3.7xl07 m3 of contaminated soil are
located at Federal facilities and NRC-licensed sites that fall within the scope of this rule.
Table 1-3 presents a rough estimate of the volumes of radioactively-contaminated soil at
various sites. These estimates are based primarily on information reported in DOE's
Integrated Data Base (DOE 94b) and NRC's Generic Environmental Impact Statement
(NRC 94).
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TABLE 1-3 ESTIMATED RADIOACTIVELY-CONTAMINATED SOIL VOLUME
AGENCY
DOE Major
Faculties
DOE National
Laboratories
Other DOE
Sites
DoD Sites
Other Federal
Sites
Non-Federal
NPL Sites
NRC/Agreemen
t
States Sites
Other State
Sites
TOTAL
SITE
NAME
Fernald
Hanford
Idaho
Mound
Nevada Test Site
Oak Ridge Reservation
Paducah
Pantex
Portsmouth
Rocky Flats
Savannah River
Weldon Spring
Argonne
Brookhaven
Fermi
Lawrence Berkeley
Lawrence Livermore
Los Alamos
Sandia
FUSRAP Sites
UMTRAP Sites
Other DOE Sites
Aberdeen Proving Ground
Sites with Burial Areas
Site w/Accident
Contamination
Sites with DU Contamination
Other DoD Sites
USDA Fremont National
Forest
GSA Watertown Arsenal
Municipal Landfills
Radium Sites
Other Non-Federal NPL Sites
Nuclear Power Plants
Test and Research Reactors
Other Fuel Cycle Facilities
Rare Earth Extraction
Facilities
Byproduct Material Facilities
-
SITE
COUN
T
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
30
14
33
1
79
1
15
51
1
1
3
7
11
125
63
65
22
4401
-
4942
DOE IDE
SOIL
VOLUM
E
1.7E6
3.86E6
6.6E5
1.57E5
1.4E7*
4.6E5
7.2E4
0
1E4
2.7E5
3.6E6
4.9E5
2.7E4
2.6E4
0
0
0
9.6E6
6.7E4
1.79E6
(3.42E7)
1.2E5
NRC GEIS/
EPA-
ESTIMATED
SOIL VOLUME
3.19E3
-
1.76E4
-
-
-
-
-
-
-
1.38E3
1.76E3
1.24E4
2.86E3
1.23E5
-
ACCOUNTED
SOIL
VOLUME
1.7E6
3.86E6
6.6E5
1.57E5
1.4E7
4.6E5
7.2E4
0
1E4
2.7E5
3.6E6
4.9E5
2.7E4
2.6E4
0
0
0
9.6E6
6.7E4
1.79E6
-
1.2E5
3.19E3
-
1.76E4
-
-
-
-
-
-
-
1.38E3
1.76E3
1.24E4
2.86E3
1.23E5
-
3.72E7m3*
NOTES
Not counted in
total
EPA estimated
volume
EPA estimated
volume
Legend: IDE - Integrated Data Base
GEIS - Generic Environment Impact Statement
* The actual soil volume used for NTS in EPA's analysis is 2.2 x 107 m3 (DOE 93d).
This leads to a total soil volume of 4.52 x 107 m3 used in the analysis.
Review Draft - 9/26/94
1-16
Do Not Cite Or Quote
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2. Selection/Development of Exposure Scenarios and Models
This chapter describes the general exposure scenarios and mathematical models EPA used in
support of the development of the soil cleanup rule to assess radiation doses and risks to
individuals and populations at sites with residual radioactivity contamination.
Section 2.1 describes the exposure scenarios EPA developed to model radiation doses and
risks to individuals assuming reasonable maximum exposure (RME) conditions—defined in
Section 2.1.2—for three different post-cleanup land use scenarios: rural residential,
commercial/industrial, and suburban. For each of these scenarios, Section 2.1 defines
principal soil exposure pathways and key exposure parameters. This section also discusses
the selection and evaluation of three different fate and transport models (i.e., RESRAD,
RAGS/HHEM, and PRESTO) used in the dose and risk calculations.
Section 2.2 describes population exposures by discussing the scenarios and assumptions used
to estimate the potential total number of radiation-induced fatal and nonfatal cancers in a
given population group exposed to various specific residual radionuclide soil concentrations.
(The population exposure scenarios and assumptions presented in this section differ
somewhat from those discussed in Section 2.1 for individual dose and risk modeling.) Two
general population scenarios are considered. The first scenario is used to evaluate radiation
doses and risks for populations with densities ranging from 10 to 300 people per square
kilometer, assuming that individuals in these populations consume locally grown produce.
The second scenario is used to evaluate radiation doses and risks assuming that population
densities range from 10 to more than 1,000 people per square kilometer, and that the populace
does not consume locally grown produce. Both scenarios assess potential human health
impacts over 100-, 1,000-, and 10,000-year time periods.
Chapter 3 provides the standardized default input parameter values assumed for modeling
doses and risks to RME individuals, along with a detailed comparison of the pathway model
structures and dose and risk estimates. Later, in Chapter 5, the rural residential and
commercial/industrial scenarios—the most conservative and least conservative exposure
scenarios, respectively—and the reference radiation site data discussed in Chapter 4 are used
to estimate human health impacts averted and volumes of contaminated soil requiring
remediation at various target risk levels.
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2.1 EXPOSURE SCENARIOS AND MODELS FOR CALCULATING RADIATION
DOSE AND RISK TO INDIVIDUALS
Cleanup regulations for contaminated soil should account for potential radiation doses and
risks to individuals from all significant exposure pathways. This section presents the exposure
pathways, scenarios, and models used to determine these doses and risks. Following a
general discussion of exposure pathways and scenarios in Section 2.1.1, Section 2.1.2 reviews
EPA's current standardized exposure scenarios, pathways, and assumptions. Section 2.1.3
presents the exposure scenarios and models assumed for calculations in this document. The
selection and evaluation of three different multi-media pathway models are discussed in
Sections 2.1.3 through 2.1.6.
2.1.1 Background
An exposure pathway describes the course a hazardous substance takes through the
environment from a source of contamination to a human or ecological receptor. Modeling the
transport of a contaminant via an exposure pathway means defining: (1) the nature, extent
and location of the contaminant source or sources, (2) actual or potential mechanisms of
release, migration, and fate in the environment, (3) a medium or media through which the
contaminant is transported or in which the contaminant remains, (4) points of possible
receptor contact with the contaminated medium, and (5) an exposure route (e.g., ingestion) or
routes at the point of contact. An exposure pathway is "complete" when all of these
components exist and are defined as completely as possible, i.e., when the path of the
hazardous substance from the source to the receptor is uninterrupted and can be documented
by measured or modeled contaminant concentrations at the exposure point locations.
Conversely, "incomplete" exposure pathways lack at least one of these components. The
primary objective of an exposure pathway analysis is to identify all significant (i.e., complete
and incomplete) exposure pathways and to provide quantitative estimates of contaminant
concentrations in all affected media for all likely exposure routes. One or several exposure
pathways may exist for any given source of contamination, and the presence or absence of an
exposure pathway is highly dependent upon several site-specific conditions, including current
and future land use, site lithology, hydrogeology, and local population density and location,
among others.
Human health risk assessment combines information from the exposure pathways
analysis—on contaminated media concentrations and exposure pathways—with exposure
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factors and toxicity criteria to estimate contaminant intakes and adverse health risks to
individuals and populations. Exposure factors include: (1) intake rates for specific exposure
routes (e.g., inhalation) or for specific exposure pathways (e.g., ingestion of drinking water),
(2) exposure rates (i.e., exposure times, frequencies and duration), and (3) modifying factors
(e.g., shielding factors for external exposure). Toxicity criteria are numerical estimates of the
possible adverse health effect that might be expected in an individual following exposure to a
unit concentration of a specific contaminant via a specific exposure route, such as inhalation,
ingestion, or dermal contact. Exposure factors are generally site-specific, depending on the
habits and activities of the local population both on- and offsite. However, many of the
exposure factors and factor values used in the assessment of one site often have similar
applications and values at other sites. Thus, these factors often are assigned standardized or
default values. In general, toxicity criteria are usually default values.
Exposure scenarios are combinations of exposure pathways and exposure assumptions that
are used to evaluate site risks under different land-use classifications. Each scenario describes
actual or potential contaminant releases, migration pathways, contaminated media, exposure
point concentrations, and receptor characteristics for a specific land use and its assumed set of
site conditions. The purpose of these scenarios is to ensure that every reasonable exposure
pathway and assumption is considered and that all individual exposures and risks are assessed
consistently and comprehensively.
2.1.2 EPA Superfund Exposure Scenarios
EPA's Superfund program currently defines exposure scenarios within the context of four
land-use classifications: residential, commercial/industrial, agricultural, and recreational (EPA
89a; EPA 9 la). Table 2-1 presents Agency definitions for each of these scenarios, along with
their corresponding most commonly evaluated exposure pathways and standard default
exposure factor values. General descriptions of these scenarios follow.
For each of these exposure scenarios, EPA applies the concept of "reasonable maximum
exposure" (RME). EPA defines RME as "the maximum exposure that [any individual] is
reasonably expected to [receive] at a site" (EPA 89a) or as the "high-end individual
exposure." (EPA 9la). In both cases, EPA describes the RME concept as an approach which
uses standardized exposure pathways and default exposure factor values to calculate
maximum reasonable estimates of contaminant intake and risk for individuals in an exposed
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Table 2-1. EPA Superfund Land Use Classifications and Standard Default Exposure Factors
Land Use
Classification
Residential
Commercial/
Industrial
Agricultural
Definition
Residential exposure scenarios and assumptions should be
used whenever there are or may be occupied residences on
or adjacent to the site. Under this land use, residents are
expected to be in frequent, repeated contact with
contaminated media. The contamination may be on the site
itself or may have migrated from it. The assumptions in this
case account for daily exposure over the long term and
generally result in the highest potential exposures and risks.
Under this type of land use, workers are exposed to
contaminants within a commercial area or industrial site.
These scenarios apply to those individuals who work on or
near the site. Under this land use, workers are expected to
be routinely exposed to contaminated media. Exposure may
be lower than that under the residential scenarios, because it
is generally assumed that exposure is limited to 8 hours a
day for 250 days per year.
These scenarios address exposure to people who live on the
property (i.e., the farm family) and agricultural workers.
Assumptions made for worker exposures under the
commercial/industrial land use may not be applicable to the
agricultural workers due to differences in workday length,
seasonal changes in work habits, and whether migrant
workers are employed in the affected area. Finally, the farm
family scenario should be evaluated only if it is known that
such families reside in the area.
Exposure
Pathway (2)
Ingestion of
potable water
Ingestion of soil
and dust
Inhalation of
contaminants
Ingestion of
potable water
Ingestion of soil
and dust
Inhalation of
contaminants
Ingestion of
potable water
Ingestion of soil
and dust
Inhalation of
contaminants
Consumption of
homegrown
produce
Daily
Intake Rate
2 liters
200 mg(child)
lOOmg(adult)
20 m3 (total)
1 5 m3(indoor)
1 liter
50 mg
20 m3 (workday)
2 liters
200 mg (child)
1 00 mg (adult)
20 m3 (total)
15m3 (indoor)
42 g (fruit)
80 g (veg.)
Exposure
Frequency
(days/year)
350
350
350
250
250
250
350
350
350
350
Exposure
Duration
(years)
30
6 (child)
24 (adult)
30
25
25
25
30
6 (child)
24 (adult)
30
30
-------
Table 2-1 (Continued)
Land Use
Classification
Definition
Exposure
Pathway(2)
Daily
Intake Rate
Exposure
Frequency
(days/year)
Exposure
Duration
(years)
Recreational
This land use addresses exposure to people who spend a
limited amount of time at or near a site while playing,
fishing, hunting, hiking, or engaging in other outdoor
activities. This includes what is often described as the
"trespasser" or "site visitor" scenario. Because not all sites
provide the same opportunities, recreational scenarios must
be developed on a site-specific basis. In the case of
trespassers, current exposures are likely to be higher at
inactive sites than at active sites because there is generally
little supervision of abandoned facilities. At most active
sites, security patrols and normal maintenance of barriers
such as fences tend to limit (if not entirely prevent)
trespassing. When modeling potential future exposures in
the baseline risk assessment, however, existing fences
should not be considered a deterrent to future site access.
Recreational exposure should account for hunting and
fishing seasons where appropriate, but should not disregard
local reports of species taken illegally. Other activities
should also be scaled according to the amount of time they
could actually occur; for children and teenagers, the length
of the school year can provide a helpful limit when
evaluating the frequency and duration of certain outdoor
exposures.
Consumption of
locally caught fish.
(Additional
pathways are
developed on a
site-specific basis.)
54 g
350
30
Footnotes: (1) Factors presented are those that should generally be used to assess exposures associated with a designated land use. Site-specific data may
warrant deviation from these values; however use of alternate values should be justified and documented in the risk assessment report.
(2) Listed pathways may not be relevant for all sites, and other exposure pathways may need to be evaluated due to site conditions.
Source: "Standard Default Exposure Factors," EPA OSWER Directive 9285.6-03, March 25, 1991.
-------
population. These individual intake and risk estimates are referred to as "maximum" or "high-
end," because they often involve the use of upper-bound (90th or 95th percentile) values as
defaults for exposure equations and calculations.
The purpose of the RME approach is to provide estimates of individual intake and risk that
are protective and reasonable—not the worst case possible. EPA developed the RME concept
and standardized exposure scenarios and assumptions (discussed in the next two sections) to:
(1) reduce unwarranted variability in the assumptions used in baseline risk assessments to
characterize potentially exposed populations, and (2) achieve consistency in evaluating site
risks and setting cleanup goals at CERCLA sites. Although the Agency does not consider the
use of RME exposure assumptions to be overly conservative, it does recognize that exposure
conditions at specific sites can and often do differ from the generic case. For this reason,
EPA encourages the use of site-specific scenarios and exposure factors to estimate intakes and
risks, provided that these assumptions can be justified and documented (EPA 89a).
2.1.2.1 EPA Superfund Residential Exposure Scenario
EPA evaluates residential exposure scenarios whenever there are homes on or near a
contaminated site, or whenever future residential development is a reasonable expectation,
considering local zoning laws, land-use trends, and site suitability. Five exposure pathways
are evaluated routinely under this scenario to assess risks from radionuclides in soil (EPA
91a):
• Direct external radiation from photon-emitting radionuclides in the soil;
• Inhalation of resuspended contaminated dust;
• Inhalation of radon and radon decay products (only when radium is present in
soil);
• Ingestion of contaminated drinking water; and
• Ingestion of contaminated soil.
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Two additional pathways—consumption of contaminated home-grown produce and fish—are
also considered at some residential sites, but only when site-specific circumstances warrant
inclusion.
2.1.2.2 EPA Superfund Commercial/Industrial Exposure Scenarios
EPA evaluates occupational exposure scenarios whenever the land use is, or is expected to be,
commercial or industrial. These scenarios typically assess adult worker exposures that
assume an exposure occurs at the workplace during an 8-hour work day, 5 days per week, 50
weeks per year, for 25 years. Exposure pathways considered under this scenario are identical
to those evaluated for residential exposures, with the omission of pathways for consumption
of home-grown produce and fish. As shown in Table 2-1, values for exposure factors and
intake rates assumed for commercial/industrial exposures are generally less than those
assumed for residential exposures.
2.1.2.3 EPA Superfund Agricultural Exposure Scenario
EPA evaluates agricultural exposure scenarios whenever individuals live or work in
contaminated areas zoned for farming activities, such as a growing crops or raising livestock.
Under this scenario, EPA assumes that farm family members are exposed through the same
five principal pathways evaluated for individuals under the residential setting, plus the
mandatory inclusion of the plant pathway (i.e., consumption of home-grown produce). EPA
also considers additional pathways for the ingestion of contaminated beef and dairy products,
but only when such pathways are valid for the site conditions and lifestyles of the onsite
populations.
2.1.2.4 EPA Superfund Recreational Exposure Scenarios.
Under the recreational exposure scenario, EPA includes pathways for consumption of locally
caught fish—both for subsistence and recreation—and for dermal exposures that might occur
during swimming and wading. Fish pathways are evaluated only when there is access to a
contaminated water body large enough to produce a consistent supply of edible-sized fish
over the anticipated exposure period. Pathways for assessing exposures during swimming
and wading are currently being re-evaluated by EPA, along with other potential recreational
exposure pathways, such as hunting and dirtbiking.
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2.1.3 Exposure Scenarios Used in the Proposed Soil Cleanup Rule Analysis to Calculate
Radiation Doses and Risks
Two principal soil exposure scenarios were developed by EPA to evaluate radiation doses and
radiation-induced cancer risks at the reference radiation sites: rural residential and
commercial/industrial. These scenarios are discussed below and outlined in Table 2-2. They
were selected because they address plausible land use and exposure situations anticipated
after cleanup at sites subject to the proposed rule. They are also generally consistent and
compatible with the corresponding Superfund land-use scenarios discussed in Section 2.1.2,
and reflect the rural and commercial/industrial settings at many of the Federal and NRC-
licensed sites subject to the proposed regulations soil cleanup regulations. Later, in Chapter 5,
the rural residential and commercial/industrial scenarios—which generally represent the most
conservative and least conservative exposure scenarios, respectively—are combined with the
reference radiation site data discussed in Chapter 4 to estimate human health impacts averted
and volumes of contaminated soil requiring remediation at various target risk levels.
A third soil exposure scenario—the suburban scenario—was also used to evaluate radiation
doses and risks to individuals. The suburban scenario considers three fewer exposure
pathways (i.e., meat, milk and fish) compared to the rural residential scenario. Also, the
suburban scenario assumes that individuals ingest slightly less contaminated home-grown
produce and inhale substantially less resuspended contaminated dust than individuals ingest
or inhale under either the rural residential or the commercial/industrial scenarios. Thus, the
suburban scenario represents a land use assumption that falls between the rural residential and
commercial/industrial cases, and results in dose and risk estimates that may be considered
moderately conservative, rather than overly conservative.
Standardized default input parameter values for these scenarios are presented in Chapter 3,
along with a comparison pathway model structures and dose and risk estimates.
2.1.3.1 Rural residential Exposure Scenario Assumed for Radiation Dose and Risk
Calculations
The rural residential exposure scenario assumed for radiation dose and risk calculations
addresses long-term risks to individuals expected to live on a site in a rural area after cleanup.
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Table 2-2. Exposure Pathways Assumed for Radiation Dose and Risk Calculations
Exposure Pathways
1 . External radiation
exposure
2. Inhalation of
resuspended soil
and dust
3 . Inhalation of radon
and radon decay
products from soil
containing radium
4. Incidental
ingestion of soil
5. Ingestion of
drinking water
6. Ingestion of home
grown produce
7. Ingestion of meat
(i.e., beef)
8. Ingestion of milk
9. Ingestion of
locally caught fish
10. Dermal
1 1 . Volitilization
Rural Residential
Exposure Scenario
Yes
Yes
Yes
(if radium is present)
Yes
Yes
Yes
Yes
Yes
Yes
No*
No*
Commercial/Industrial
Exposure Scenario
Yes
Yes
Yes
(if radium is present)
Yes
Yes
No
No
No
No
No*
No*
Suburban
Exposure Scenario
Yes
Yes
Yes
(if radium is present)
Yes
Yes
Yes
No
No
No
No*
No*
* Some models account indirectly for dermal exposure to tritiated water or C-14 in organic
compounds. (See Section 2.1.7.)
-------
Under this scenario, individuals are assumed to live onsite and to be exposed
chronically—both indoors and outdoors—to residual concentrations of radionuclides in soil
through all the exposure pathways listed in Table 2-2. This scenario is based primarily on
Superfund's standardized agricultural scenario and exposure pathways, except that the
residents are not assumed to be full-time agricultural workers. Instead, it is assumed that
these individuals work primarily off site and engage only in light farming and recreational
activities onsite. Furthermore, it is assumed that 50% of the locally grown produce, meat,
milk, and fish that these individuals consume are assumed to come from the site and are
contaminated (see Chapter 3).
Under the rural residential scenario, a total of nine exposure pathways are evaluated:
• External radiation exposure from photon-emitting radionuclides in soil;
• Inhalation of resuspended soil and dust containing radionuclides;
• Inhalation of radon (Rn-222 and Rn-220) and radon decay products from soil
containing radium (Ra-226 and Ra-224);
• Incidental ingestion of soil containing radionuclides;
• Ingestion of drinking water containing radionuclides transported from soil to
potable groundwater sources;
• Ingestion of home-grown produce (fruits and vegetables) contaminated with
radionuclides taken up from soil;
• Ingestion of meat (beef) containing radionuclides taken up by cows grazing on
contaminated plants (fodder);
• Ingestion of milk containing radionuclides taken up by cows grazing on
contaminated plants (fodder); and
• Ingestion of locally caught fish containing radionuclides.
EPA selected this scenario and combination of exposure pathways to compute relatively
conservative (i.e., stringent) post-cleanup dose and risk estimates for a future resident in a
rural area.
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2.1.3.2 Commercial/Industrial Exposure Scenario Assumed for Radiation Dose and Risk
Calculations
The commercial/industrial exposure scenario used in the radiation dose and risk calculations
is identical to the one defined by Superfund (see Section 2.1.2.2). This scenario addresses
long-term exposures and risks to commercial or industrial workers exposed daily to residual
levels of radionuclides in soil during an average 8-hour workday onsite, both indoors and
outdoors. This scenario does not consider exposures to site remediation workers or
construction workers, nor does it address risks to workers from contaminated structures or
building materials. Exposures that occur during cleanup are addressed in Section 5.3.
Under the commercial/industrial exposure scenario, a total of five pathways are evaluated:
• External radiation exposure from photon-emitting radionuclides in soil;
• Inhalation of resuspended soil and dust-containing radionuclides;
• Inhalation of radon (Rn-222 and Rn-220) and radon decay products from soil
containing radium (Ra-226 and Ra-224);
• Incidental ingestion of soil containing radionuclides; and
• Ingestion of drinking water containing radionuclides transported from soil to
potable groundwater sources.
EPA selected the commercial/industrial scenario and associated exposure pathways to
compute the risks to workers assuming RME conditions for the workplace. In general, for
sites with identical radionuclide soil concentrations, exposures and risks to onsite workers will
generally be less than those for residents of rural and suburban areas, because worker
exposures are limited to working hours and do not include contributions from ingestion of
home-grown produce or locally caught fish. As a result, risks and doses for workers are
expected to be consistently lower than those for individuals assuming suburban or rural
residential exposures.
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2.1.3.3 Suburban Exposure Scenario Assumed for Radiation Dose and Risk Calculations
The suburban exposure scenario assumed for radiation dose and risk calculations addresses
long-term risks to individuals expected to live on a site that has no active control measures
designed to limit exposure after remediation. This scenario assumes that individuals live
onsite and are exposed chronically, both indoors and outdoors, to residual concentrations of
radionuclides in soil through a reasonable (but not maximum) number of exposure pathways.
This scenario is based primarily on Superfund's standardized residential scenario and
exposure pathways—defined in Section 2.1.2.1—with one modification: Ingestion of
homegrown produce is also included. As a result, a total of six exposure pathways are
evaluated under the suburban exposure:
• External radiation exposure from photon-emitting radionuclides in soil;
• Inhalation of resuspended soil and dust containing radionuclides;
• Inhalation of radon (Rn-222 and Rn-220) and radon decay products from soil
containing radium (Ra-226 and Ra-224);
• Incidental ingestion of soil containing radionuclides;
• Ingestion of drinking water containing radionuclides transported from soil to
potable groundwater sources; and
• Ingestion of home-grown produce (fruits and vegetables) contaminated with
radionuclides taken up from soil.
EPA selected this scenario and combination of exposure pathways to compute the risk to an
individual assuming reasonable maximum exposure (RME) conditions that would result in
moderately conservative radiation dose and risk estimates.
2.1.3.4 Exposure Scenarios Assumed by the DOE and the NRC
In general, the Department of Energy (DOE) and the Nuclear Regulatory Commission (NRC)
consider similar land-use scenarios in the remediation of actual sites (DOE 93a; NRC 92b).
However, in some cases, DOE or NRC may evaluate additional exposure scenarios and
pathways that are not based on any specific land-use consideration—such as the intruder
exposure scenario—or may apply different default values for exposure factors and intake
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rates than those currently recommended by EPA. (Appendix B compares EPA, DOE, and
NRC default exposure factor values.) It should be noted, however, that all three agencies
strongly recommend the use of site-specific data for modeling doses and risks, but only when
the data are available and meet appropriate data quality objectives and data usability
requirements.
2.1.4 Basic Soil Exposure Pathway Models
Radionuclide contamination in soil can enter the human body from any combination of the
following five general media/pathways:
The atmosphere (inhalation of suspended dust)
• Surface water (ingestion of surface water contaminated by runoff or leachate)
Groundwater (ingestion of groundwater contaminated by leachate)
• Soil (direct ingestion of contaminated soil)
• Biota (ingestion of food items contaminated by root uptake, deposition, irrigation)
In addition, radioactive contamination in any media can result in direct external radiation
exposure. Models that include all of these pathways are often called "multimedia."
A broad range of multimedia models and computer codes were reviewed to identify those
models and codes that meet the modelling needs for this rulemaking. The following describes
the model evaluation process and the models selected for use in support of the rulemaking.
2.1.5 Model Evaluation/Selection Criteria
Five criteria were identified for evaluating and selecting pathway models for use in model
calculations. These require that pathway models be:
Capable of addressing multiple exposure pathways and risks from radionuclides in
soil, including:
— External radiation exposure
— Soil ingestion
— Plant, meat, and milk ingestion
— Inhalation of volatiles and fugitive dusts
— Migration of radionuclides to groundwater
— Ingestion of contaminated drinking water
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• Validated, peer-reviewed, or generally accepted by radiation risk assessors (with
preference given to EPA-approved or accepted methods).
• User-friendly with a manageable number of input parameters requiring minimal or
modest amounts of site data.
• Computer encoded or amenable to simple hand calculations.
• Currently in use or planned for use at radiation sites (all models identified for
evaluation were considered to be currently in use).
2.1.6 Pathway Models/Codes Evaluated
EPA has examined a number of models for use in estimating human health risks associated
with radioactive materials present in soils. Table 2-3 presents a list of potential candidate
multimedia models/codes with a brief description of representative ways in which each of the
listed codes are used. The list was prepared through:
• Analysis of code survey data and reports (EPA 88a; EPA 88b; EPA 89a; EPA 89b;
EPA91a;EPA93c)
• Use of the EPA Integrated Model Evaluation System (IMES) and the
Environmental Models Library (EML)
• Discussions with project staff.
• Review of scientific and vendor literature
In developing this initial list of codes, no attempt was made to determine "apriori" the degree
to which these models could be appropriately applied to sites contaminated with radioactive
materials. Table 2-4 presents the evaluation of representative pathway models against the
listed criteria. A "/"" indicates that the evaluation criterion is included in the model, while the
absence of a "/" indicates that the information was not available from the referenced sources.
2.1.7 Pathway Models Selected
Based on the evaluation criteria, EPA tentatively selected DOE's RESRAD computer code
(version 5.19) to model individual risks at reference radiation sites. Two additional
Review Draft - 9/26/94 2-14 Do Not Cite Or Quote
-------
Table 2-3. Examples of Code Usage
Code Name
ARCL
DECHEM
DITTY
DOSES
GENII
GENII- S
GEOTOX
GWSCREEN
MEPAS
MILDOS
MILDOS-AREA
MUL TIMED
NUREG 0707
NUREGCR/5512
NUTRAN
ONSITE/MAXI1
PATH
PATH1
Description of Representative Usage
Evaluates decommissioning alternatives by using a site-specific radiation
scenario/exposure pathway analysis to determine the acceptable concentrations of
residual radioactive contaminants.
Determines acceptable concentrations of chemicals in soil after cleanup of Uranium
Mill Tailings Remedial Action Project sites.
Determines the collective dose from long-term nuclear waste disposal sites resulting
from groundwater pathways.
Estimates long-term dose to man from buried waste.
Used to estimate potential radiation doses to humans from radionuclides in the
environment.
Developed for use in performance assessment for the Waste Isolation Pilot Plant at
Sandia National Laboratories.
Evaluates health risks due to the presence of TNT, RDX and benzene present in
military explosives residuals.
Developed for assessment of groundwater pathway from leaching of radioactive and
nonradioactive substances from surface or buried sources.
A risk computation system developed for hazard ranking applications.
Computes environmental radiation doses from uranium recovery operations.
Provides improved capability for handling large area sources and updates the
dosimetry calculations.
EPA Toxicity Characteristic Final Rule.
Estimates site-specific limits for allowable residual contamination.
Provides generic and site-specific guidance of radiation doses for exposures to
residual radioactive contamination after the decommissioning of facilities licensed
by the NRC.
Calculates the consequences of groundwater releases of radioactivity from a waste
repository.
NRC review of license applications for onsite disposal of radioactive wastes.
Used to implement residual radioactive material guidelines during decommissioning.
Models the physical and biological processes that result in the transport of
radionuclides through the Earth's surface environment and eventual human exposure
to these rnrhonnr.lirles
-------
Table 2-3 (Continued)
Code Name
PATHRAE (EPA)
PC GEMS
PRESTO-EPA
PRESTO-EPA-
BRC
PRESTO-EPA-
CPG
PRESTO-EPA-
POP
PRESTO-EPA-
DEEP
PRESTO-II
RAGS/HHEM
RESRAD
RISKPRO
SARAH2
UDAD
UTM-TOX
Description of Representative Usage
Maximum annual effective dose equivalent to a critical population group and to
offsite populations at risk from the land disposal of radioactive wastes.
Used to evaluate the spread of toxic chemicals released to air, soil, surface water,
and groundwater.
Simulates transport of low-level radioactive waste material from a shallow trench
site and assesses human risks associated with such transport. This model was
modified and added to create the PRESTO family of models.
Modified version of PRESTO-EPA-POP. Additions to this model include
estimation of radionuclide transport and exposure to workers and visitors, population
exposures from incinerator releases, worker and visitor gamma exposures, and onsite
farming.
Max. whole body dose to critical population groups from land disposal of low-level
radioactive waste by shallow and deep methods.
Cum. population health effects to local and regional basin populations from low-
level waste disposal by shallow land methods.
Cum. population health effects to local and regional populations from land disposal
of low-level radioactive wastes by deep methods.
Evaluation of possible health effects from shallow-land and waste disposal trenches.
Assists Superfund personnel to develop preliminary remediation goals at CERCLA
sites.
An analytical methodology recommended by the Department of Energy in its
guidelines for allowable concentrations of residual radioactive material in soil
encompassed by the Formerly Utilized Sites Remedial Action Program (FUSRAP)
and Surplus Facilities Management Program.
Used to evaluate the spread of toxic chemicals released to air, soil, surface water,
and groundwater. RISKPRO was adapted from PCGEMS.
Core equations developed in support of the EPA "Land Disposal Banning Rule."
Estimates potential radiation exposure to individuals and to the general population in
the vicinity of a uranium processing facility.
A multi-media model which links an atmospheric transport model with a surface
water model.
-------
Table 2-4. Pathway Model Evaluation
Model
Name
DECHEM
GENII
GENII- S
GEOTOX
GWSCREEN
RAGS/HHEM
RAGS/HHEM
Modified1
MEPAS
MILDOS-AREA
MMSOILS
MULTMED
NUREG5512
ONSITE/MAXI1
Exposure Pathways
External
Exposure
/
/
/
/
/
/
/
Soil
Ingestion
/
/
/
/
Plant,
Meat,
Milk
Ingestion
/
/
/
/
/
/
/
/
/
Inhalation
Particulates
/
/
/
/
/
/
/
/
/
/
/
Radon
/
/
/2
/
?
Ground
Water/Leach
Model
/
/
/
/
/
/
/
/
/
Validated/
Peer-
Reviewed
/
/
/
/
/
Site
Data
Required
Moderate
Moderate
Minimal
Minimal
Extensive
Moderate
Available
Computer
Code
/
/
/
/
/
/
/
/
/
/
-------
Table 2-4 (Continued)
Model
Name
PATH1
PATHRAE
PRESTO-EPA-CPG
PRESTO-EPA-POP
PRESTO-II
RESRAD
RISKPRO
SARAH2
Exposure Pathways
External
Exposure
/
/
/
/
/
/
Soil
Ingestion
/
/
/
/
Plant,
Meat,
Milk
Ingestion
/
/
/
/
/
/
Inhalation
Particulates
/
/
/
/
/
/
/
Radon
/
/
Ground
Water/Leach
Model
/
/
/
/
/
/
/
Validated/
Peer-
Reviewed
/
/
/
/
Site
Data
Required
Minimal
Moderate
Moderate
Moderate
Moderate
Moderate
Available
Computer
Code
/
/
/
/
/
/
/
/
1 The RAGS-HHEM Part B equations were modified to include recommendations from Dra// Guidance for Soil Screening Level Framework (EPA 94).
2 The RAGS-HHEM Part B equation for inhalation of radon only accounts for outdoor radon. The modified equation accounts for indoor radon as well.
-------
models—PRESTO and RAGS/HHEM—are being studied and employed for related purposes
(discussed below). EPA's PRESTO-CPG, and a code based upon an expanded version of
EPA's RAGS/HHEM Part B (modified for consistency with the Agency's Draft Guidance for
Soil Screening Level Framework (EPA 94). These three pathway models were considered
because they meet the majority of the evaluation criteria. Table 2-5 compares each of the
three models by pathway.
The RESRAD computer code was developed to implement DOE requirements for residual
radioactive material. RESRAD calculates doses and risks to an onsite individual. This is a
multimedia model which incorporates a number of media-specific sub-models, all of which
were chosen for their reliability and general conservatism. Pathway analysis is performed in
four stages: source analysis, environmental transport analysis, dose/response analysis, and
scenario analysis. Additional information on the RESRAD computer code is available in the
Manual for Implementing Residual Radioactive Material Guidelines Using RESRAD, Version
5.0(DOE93a).
EPA developed the PRESTO family of computer codes to assist in the development of
standards for the disposal of low-level radioactive waste. PRESTO-EPA-CPG predicts the
maximum individual dose resulting from the multiple pathway migration of radionuclides
from low-level waste disposal facilities. EPA's Science Advisory Board reviewed this
computerized-exposure model in 1985 as part of their review of the proposed Low-Level
Waste Rule (EPA 88a). A moderate amount of site-specific data is required to run the model.
Additional information on the PRESTO family of codes is available in: (I) Low-Level and
NARM Radioactive Wastes, Model Documentation, PRESTO-EPA-CPG (EPA 87), and (2)
Modifications to the PRESTO-CPG Code to Facilitate the Analysis of Soil Contamination
Sites (RAE 94).
EPA's Office of Radiation and Indoor Air (ORIA) modified the RAGS/HHEM Part B model
(EPA 9 la) primarily to address the recommendations provided in EPA's Draft Guidance for
Soil Screening Level Framework (EPA 94). Modifications were also made to Part B to
account for:
• Inhalation of radon and particulates to include indoor radon exposure
• Migration to groundwater (i.e. drinking water pathway)
• Plant, meat, milk, and fish ingestion.
Review Draft - 9/26/94 2-19 Do Not Cite Or Quote
-------
Table 2-5. Comparison of Pathway Models
Pathway
General
External
Inhalation of
Soil and Dust
Inhalation of
Radon2
Soil Ingestion
Parameter
Converts radionuclide concentration in soil to risk
using slope factors.
Corrects radionuclide concentration in soil for
primary radionuclide decay, and ingrowth and decay
of daughter radionuclides.
Corrects radionuclide concentration in soil for
environmental transport (i.e., leaching, atmospheric
transport, surface and groundwater transport).
Corrects for indoor and outdoor exposure.
Corrects for exposure time and frequency. '
Corrects for exposure duration. '
Includes a gamma shielding factor for indoor
exposure.
Includes an air/soil concentration factor to estimate
soil particle resuspension.
Calculates soil particle resuspension based on wind
velocity and mechanical factors (i.e., digging,
plowing, etc.).
Corrects for dilution of suspended particles based on
site area.
Corrects for cover material and depth of
contamination.
Corrects for exposure time and frequency.
Corrects for exposure duration.
Calculates radon exposure indoors and outdoors based
on volatilization factors for Rn-222 and Rn-220.
Calculates radon exposure outdoors based on Rn-222
and Rn-220 flux at the soil surface.
Calculates radon exposure indoors based on Rn-222
and Rn-220 flux through the building floor and radon
in household water, corrected for radon removal by
air exchange and radioactive decay.
User input human inhalation rate.
Corrects for exposure time and frequency.
Corrects for exposure duration.
User input human ingestion rate.
Pathway Model
RAGS/HHEM
/
/
/
/
/
/
/
/
/
/
/
/
/
PRESTO
/
/
/
/
/
/
/
/
RESRAD
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
Review Draft - 9/26/94
2-20
Do Not Cite Or Quote
-------
Table 2-5 (Continued)
Pathway
Soil Ingestion
(Continued)
Water
Ingestion
Parameter
Corrects for fraction of play or work area included in
the contaminated zone.
Corrects for inert cover material and depth of
contamination.
Corrects for exposure time.
Corrects for exposure frequency.
Corrects for exposure duration.
User input human ingestion rate.
Calculates radionuclide concentration in pore water
based on radionuclide specific distribution
coefficients.
Calculates radionuclide concentration in groundwater
based on user input dilution factor.
Calculates radionuclide concentration in groundwater
based on pore water concentration, transport
retardation factor based on distribution coefficients,
leach rate based on infiltration factors (i.e.,
precipitation and irrigation rates, soil porosity, etc.),
and a calculated dilution factor.
Groundwater dilution factor based on dispersion
plume, aquifer flow rate, and groundwater usage.
Groundwater dilution factor based on site surface
area, infiltration rate, and groundwater usage.
Corrects for transport retardation using distribution
coefficients.
Corrects for leach rate based on infiltration factors.
Corrects for surface runoff.
Calculates radionuclide concentration in surface
water (i.e., stream or pond) based on pore water
concentration and surface water dilution factor.
Surface water dilution factor based on area of
contaminated zone and area of watershed.
Surface water dilution factor based on infiltration rate
and stream flow rate.
Corrects for exposure duration.
Uses separate distribution coefficients for surface
soil, contaminated material, unsaturated zone, and
saturated zone.
Pathway Model
RAGS/HHEM
/
/
/
/
/
/
/
/
PRESTO
/
/
/
/
/
/
/
/
/
/
/
/
RESRAD
/
/
/
/
/
/
/
/
/
/
/
/
Review Draft - 9/26/94
2-21
Do Not Cite Or Quote
-------
Table 2-5 (Continued)
Pathway
Water
Ingestion
(Continued)
Ingestion of
Produce3
Ingestion of
Meat
Parameter
Contains option for using solubility of waste instead
of distribution coefficients for leach rate calculations.
User input human ingestion rates.
Calculates the radionuclide concentration in plants
based on radionuclide specific soil/plant transfer
factors.
Calculates the radionuclide concentration in plants
based on atmospheric deposition.
Calculates radionuclide concentration in plants based
on rural residential productivity, plant exposure time
during growing season, the radionuclide removal rate
(weathering), and the time interval between harvest
and consumption.
Corrects the radionuclide concentration in leafy
vegetables based on the vegetative fraction of the
plant.
Corrects the radionuclide concentration in fruits and
non-leafy vegetables based on the reproductive
fraction of the plant.
Calculates the radionuclide concentration in plants
based on ditch and overhead (spray) irrigation.
Calculates the radionuclide concentration in pasture
grass and animal fodder for the meat and milk
ingestion pathways.
Corrects for exposure duration.
Includes a separate calculation for tritium and carbon-
14 based on air/plant transfer factors.
Includes a separate calculation for tritium and carbon-
14 based on specific activity and distribution of
hydrogen and carbon in the environment.
User input human ingestion rates.
Calculates the radionuclide concentration in meat
based on radionuclide specific plant/meat transfer
factors, soil/plant transfer/factors, and the fodder
intake rate for livestock.
Calculates the radionuclide concentration in meat
based on intake of contaminated water by livestock.
Calculates the radionuclide concentration in meat
based on intake of contaminated soil by livestock.
Pathway Model
RAGS/HHEM
/
/
/
/
/
PRESTO
/
/
/
/
/
/
/
/
/
/
/
/
/
RESRAD
/
/
/
/
/
/
/
/
/
/
Review Draft - 9/26/94
2-22
Do Not Cite Or Quote
-------
Table 2-5 (Continued)
Pathway
Ingestion of
Meat
(Continued)
Ingestion of
Milk
Ingestion of
Fish
Parameter
Corrects for the time interval between slaughter and
consumption.
Corrects for exposure duration.
User input human ingestion rates.
Calculates the radionuclide concentration in milk
based on radionuclide specific plant/milk transfer
factors, soil/plant transfer/factors, and the fodder
intake rate for livestock.
Calculates the radionuclide concentration in milk
based on intake of contaminated water by livestock.
Calculates the radionuclide concentration in milk
based on intake of contaminated soil by livestock.
Corrects for the time interval between milking and
consumption.
Corrects for exposure duration.
User input human ingestion rates.
Calculates radionuclide concentration in fish based on
radionuclide specific surface water/fish transfer
factors.
Calculates radionuclide concentration in Crustacea
and mollusks based on radionuclide specific surface
water/seafood transfer factors.
Corrects for exposure duration.
Pathway Model
RAGS/HHEM
/
/
/
/
/
/
/
PRESTO
/
/
/
/
/
/
/
/
/
/
RESRAD
/
/
/
/
/
/
/
1 Exposure time, frequency, and duration can be adjusted for suburban or commercial/industrial scenarios.
2 PRESTO currently provides no calculation of risk from radon inhalation.
3 Produce includes fruits, leafy vegetables, non-leafy vegetables, and/or grains.
Review Draft - 9/26/94
2-23
Do Not Cite Or Quote
-------
The RAGS/HHEM model consists of a simple set of soil exposure pathway equations
consisting of linear combinations of exposure and intake factors that are used to obtain
radionuclide risk estimates and risk-based radionuclide soil concentrations corresponding to
specified target risk levels. There are minimal data requirements for these equations and the
results are generally limiting or bounding. Appendix C presents the modified RAGS/HHEM
equations for the rural residential and commercial/industrial scenarios.
Four additional models come close to meeting the evaluation criteria and may require further
consideration. These models are GENII, GENII-S, MEPAS, and NUREG/CR-5512. The
GENII and GENII-S do not include groundwater models. MEPAS requires extensive site-
specific data but is the only model reviewed that calculates risks from chemical sources as
well as radioactive materials (the RESRAD code for calculating chemical risks, RESCHEM,
should be available in 1995). MEPAS is also currently limited because it does not address
onsite exposure pathways. The models described in NUREG/CR-5512 do not include a radon
inhalation pathway and its coded version (D&D SCREEN) is not yet available, although the
NRC is currently preparing the code for wide use in decommissioning activities.
The following subsections compares the similarities and differences between RESRAD,
PRESTO, and RAGS/HHEM. To make the comparison as meaningful as possible, some
features of RESRAD and PRESTO were not utilized for the generic test site calculations;
these are specified below. Later, Section 3 compares the results calculated when the three
models are applied to a generic test site and discusses differences among the three models.
2.1.7.1 Source Term
The contaminated zone is the below ground region within which radionuclides are present in
above-background concentrations. It is sometimes referred to as the source term and serves
as the starting point for all pathways.
The time dependence and leaching strength of the source term, or concentration of the
radionuclide in water and soil, are calculated differently by the three models. The differences
are critical, because all of the fate and transport calculations are based on the source term.
Decrease in radionuclide concentration in the contaminated zone leads to reduced direct
exposure, resuspension exposure, etc., but may be accompanied by an increase of exposure
via the groundwater pathway.
Review Draft - 9/26/94 2-24 Do Not Cite Or Quote
-------
The modified RAGS/HHEM model is the simplest and most conservative of the three models
considered here. It does not include any corrections for radioactive decay or progeny
ingrowth, nor does it provide for depletion of the radionuclide concentration in the
contaminated soil by leaching or erosion. When ingrowth is expected to be of importance, the
progeny are included at the outset. Accordingly, the contaminated zone is assumed to be a
constant, non-depleting source of radioactivity for the calculations. This assumption provides
an upper bound estimate of exposure from radionuclides in the soil. RAGS/HHEM assumes
that adsorption is linear and can be described by the Freundlich equation, as is discussed in
Section 2.1.7.2.
RESRAD 5.19 calculates a time-dependent source term that accounts for radioactive
ingrowth, decay, and also leaching and erosion in the contaminated zone. In RESRAD, the
release rates and concentrations are driven by three factors: infiltration rates, radionuclide-
specific distribution coefficients, and source strength. The infiltration rate is used to
determine the vertical groundwater velocity through the source term (i.e., infiltration rate is
divided by the volumetric water content) (DOE 93a, pp. 198-201). The radionuclide velocity
downward through and from the source term is then determined by adjusting the groundwater
velocity by a retardation factor, derived from the radionuclide-specific distribution coefficient.
The radionuclide migration rates are subsequently used in conjunction with the source-term
thickness to determine the percentage of radionuclide that would be exiting from the base of
the contaminated zone. Finally, this release rate is multiplied by the specific activity to
calculate the release concentration.
Assumptions inherent within this approach include:
• Sorption (adsorption of radionuclide ions to soil particles) is linear in
radionuclide concentration in water, totally reversible and instantaneous.
• Infiltration is uniform and at steady-state.
• All porosity is effective, that is, there are no dead-end pores, and all
radioactivity (in curies) in the source term is being reached by the infiltrating
water and are available for transport.
Review Draft - 9/26/94 2-25 Do Not Cite Or Quote
-------
These assumptions, particularly the last one, result in very conservative leaching
concentrations.
Radionuclides in RESRAD are divided into two groups for ingrowth and decay calculations:
those with half-lives longer than six months (principal radionuclides) and those with half-lives
of six months or less (associated radionuclides) (see Table 2-6).l RESRAD assumes that the
associated radionuclides are in secular equilibrium with their principal radionuclide, and that
the leach rates of the associated radionuclides are the same as the leach rates of their principal
radionuclides (DOE 93a).
PRESTO-CPG, the third model in this comparison, also calculates a time-dependent source
term in soil resulting from radioactive decay, infiltration and erosion in the contaminated
zone. Currently, PRESTO does not calculate radioactive ingrowth while performing
groundwater areal source calculations from a series of point sources.2
PRESTO has five options to calculate the leach rate; 1) total contact/retarded by sorption, 2)
immersed fraction/retarded by sorption, 3) total contact/solubility limit, 4) immersed
fraction/solubility limit, and 5) released fraction. The method that was selected for this
investigation was the immersed fraction/retarded by sorption option, although the first option,
total contact/retarded by sorption, would have proven equally useful.
In the immersed fraction/retarded by sorption option, the pore-water concentration is
calculated by simply partitioning the radionuclide(s) among the water and soil phase
according to their respective distribution coefficients (Kd). This pore-water concentration is
then adjusted through multiplication by the relative hydraulic conductivity of the soil (i.e.,
infiltration (m/yr) divided by hydraulic conductivity (m/yr)).
The distinction between relative hydraulic conductivity and hydraulic conductivity is
important for understanding the source-term release calculation. Hydraulic conductivity is
1 RESRAD Version 5.19 also allows calculations using principal radionuclides with half-lives longer than
30 days. Calculations using principal radionuclides with half-lives longer than six months were selected
for these calculations because of the 1,000 year time frame. After one year, 25% of a radionuclide with a
half-life of six months remains, while only 0.02% of a radionuclide with a half-life of 30 days remains.
2 A PRESTO-CPG code update that includes radioactive ingrowth will be available in Fall 1994.
Review Draft - 9/26/94 2-26 Do Not Cite Or Quote
-------
Table 2-6. Principal and Associated Radionuclides*
Principal Radionuclide a
Nuclide
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-241
Am-243+D
Bi-207
C-14
Cd-109
Ce-144+D
Cl-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Half-life (yr)
22
127
0.7
432
7.4 xlO3
38
5,730
1.3
0.8
3.0 xlO5
28
18
3.5x 105
0.7
5
2
3x 106
30
Associated Decay Chain b
[Th-227 (98.6%, 19d)]
Fr-223 (1.4%, 22mm)
Ra-223(ll d)
Rn-219(4s)
Po-215(2ms)
Pb-211 (36mm)
Bi-211 (2mm)
[Tl-207 (99.7%, 5 mm)
Po-211 (0.3%, 0.5s)]
d
Ag- 108 (9%, 2 mm)
Ag-1 10(1%, 25s)
_
Np-239 (2 d)
_
_
_
[Pr-144 (9o/0j 17 mm)
Pr-144m (2%, 7 mm)]
_
_
_
_
_
_
_
_
Ba- 137m (95%, 3mm)
Terminal Nuclide or
Radionuclide0
Nuclide
Pb-207
Pd-108 (91%)
[Cd-108 (98%)
Pd-108 (2%)]
Cd-110(99%)
[Cd-110(99.7%)
Pd-110(0.3%)
Np-237
Pu-239
Pb-207
N-14
Ag-1 09
Nd-144
S-36
Am-243 (0.2%)e
Pu-240
Pu-244 (92%)
Fe-57
Ni-60
Ba-134(~100%)
Ba-135
Ba-137
Half-life
(yr)
*
*
*
*
*
*
*
2.1 x 106
2.4 xlO4
*
*
*
*
*
7.4 x 103
6.6 xlO3
8.3 x 107
*
*
*
*
*
Review Draft - 9/26/94
2-27
Do Not Cite Or Quote
-------
Table 2-6 (Continued)
Principal Radionuclide"
Nuclide
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237+D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241+D
Pu-242
Pu-244+D
Half-life (yr)
13
8
5
o
3
0.7
12
1.6 xlO7
1.3 x 109
0.9
3
2.0 x 104
7.5xl04
100
2.1 xlO6
3.3x 104
22
3
88
2.4 xlO4
6.5 x 10 3
14
3.8xl05
8.3 x 107
Associated Decay Chain b
-
_
_
_
_
_
_
-
_
_
_
_
_
Pa-233 (27 d)
_
Bi-210 (5 d)
Po-210(138d)
_
_
_
_
[Am-241 (-100%, 432 y)
U-237 (7 d)]e
_
U-240(~100%, 14 h)
Np-240
Terminal Nuclide or
Radionuclidec
Nuclide
Sm-152(72%)
Gd-152(28%)
Gd- 154 (-100%)
Gd-155
Mn-55
Eu-153
He-3
Xe-129
Ca-40 (89%)
Ar-40(ll%)
Cr-54
Ne-22
Mo-94
Co-59
Cu-63
U-233
Ac-227
Pb-206
Sm-147
U-234
U-235
U-236
Np-237
U-238
Pu-240
Half-life
(yr)
*
l.lxlO14
*
*
*
*
*
*
*
*
*
*
*
*
*
1.6 xlO5
22
*
l.lxlO11
2.4 x 105
7xl08
2.3 x 106
2.1 xlO6
4.5 xlO9
6.5 x 103
Review Draft - 9/26/94
2-28
Do Not Cite Or Quote
-------
Table 2-6 (Continued)
Principal Radionuclide"
Nuclide
Ra-226+D
Ra-228+D
Ru-106+D
Sb-125+D
Sm-147
Sr-90+D
Tc-99
Th-228+D
Th-229+D
Th-230
Th-232
Tl-204
U-232
U-233
U-234
Half-life (yr)
1.6 x 103
8
1
3
1.1 x 1011
29
2.1 x 105
2
7.3x 103
7.7 x 104
1.4 xlO10
4
72
1.6 xlO5
2.4 x 105
Associated Decay Chain b
Rn-222 (4 d)
Po-218(3mm)
Pb-214 (-100%, 27 mm)
Bi-214(20mm)
Po-214 (-100%, 1 mm)
Ac-228 (6 h)
Rh-106 (30 s)
Te-125m (23%, 58 d)
_
Y-90 (64 h)
_
Ra-224 (4 d)
Rn-220 (56 s)
Po-216 (0.2 s)
Pb-212 11 h)
Bi-212 (61 mm)
[Po-212 (64%, 0.3 us)
Tl-208 (36%, 3 mm)]
Ra-225(15d)
Ac-225 (10 d)
Fr-221 (5 min)
At-217(32ms)
Bi-213 (46mm)
[Po-213 (98%, 4 us)
Tl-209 (2%, 2 mm)]
Pd-209 (3 h)
_
_
_
_
_
Terminal Nuclide or
Radionuclidec
Nuclide
Pb-210
Th-228
Pd-106
Te-125
Nd-143
Zr-90
Ru-99
Pb-208
Bi-209
Ra-226
Ra-228
Pb-204 (97%)
Hg-204 (3%)
Th-228
Th-229
Th-230
Half-life
(yr)
22
2
*
*
*
*
*
*
*
1.6 x 103
6
*
*
2
7.3xl03
8x 104
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Table 2-6 (Continued)
Principal Radionuclide"
Nuclide
U-235+D
U-236
U-238+D
Zn-65
Half-life (yr)
7.0 x 108
2.3 xlO6
4.5 x 109
0.7
Associated Decay Chain b
Th-231 (26 h)
_
Th-234 (24 d)
[Pa-234m (99.8%, 1 mm)
Pa-234 (0.2%, 7 h)]
-
Terminal Nuclide or
Radionuclidec
Nuclide
Pa-231
Th-232
U-234
Cu-65
Half-life
(yr)
3.4 x 104
1.4 xlO10
2.4 x 105
*
Radionuclides with half-lives greater than six months. "+D" designates principal radionuclides with associated decay chains.
The chain of decay products of a principal radionuclide extending to (but not including) the next principal radionuclide or a stable
radionuclide. Half-lives are given in parentheses. Branches are indicated by square brackets with branching ratios in parentheses.
The principal radionuclide or stable nuclide that terminates an associated decay chain. Stable nuclides are indicated by an asterisk (*) in
place of a half-life.
A hyphen indicates that there are no associated decay products.
The branching decay for Pu-241 and Cm-243 involves multiple principal radionuclides and associated radionuclides.
Table adapted from: C. Yu, et al. (1994), "Manual for Implementing Residual Radioactive Materials Guidelines Using RESRAD,
Version 5.0," Argonne National Laboratory (DOE 94a).
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the measure of the soil's ability to transmit water when submitted to a hydraulic gradient. The
relative hydraulic conductivity is dependent not only upon the intrinsic properties of the soil,
but also upon the degree of soil saturation. A soil that is near complete saturation will have a
high relative hydraulic conductivity, although its hydraulic conductivity may be quite low.
If the relative hydraulic conductivity of the soil is equal to unity, the soil would be fully
saturated and the leachate would be released at full strength. Under site conditions where the
hydraulic conductivity of the soil exceeds the infiltration rates (m/y) (i.e., relative hydraulic
conductivity becomes smaller), there will be a corresponding decrease in the release
concentrations. The rationale for this approach is that soils that tend to have high relative
hydraulic conductivities (i.e., clays), will also allow for longer contact times between the
infiltrating water and the contaminants. This increase in contact time will, in turn, enable
more of the contamination to be dissolved into the pore water. The concentration in the water
is subsequently multiplied by the infiltration rate and source area to obtain the mass flux
leaving the source.
Assumptions inherent within this approach include:
• Sorption is a function of soil contact time which may be described using a
relative permeability correction factor (e.g., infiltration divided by hydraulic
conductivity).
• Infiltration is uniform and at steady-state; the code does allow infiltration rate
to vary with time.
The impact that the relative permeability correction factor has on the leach rate is significant.
In the base case analysis the infiltration rate was 0.5 m/y, whereas the hydraulic conductivity
was 227 m/y. This results in a relative permeability factor of 0.002. Therefore, the release
concentration would be 0.2% of the pore water concentration.
Figure 2-1 compares the relative effects of the different source-term release formulations in
RESRAD, PRESTO, and RAGS/HHEM on the release concentrations. In this example, the
time-variant radionuclide concentration in soil is shown for a Kd value of zero in a
contaminated zone that is 2 m thick, as calculated by all three models. While 80% of the
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radionuclide is leached from the contaminated zone in the first year using RESRAD, only 6%
of the radionuclide concentration is leached using PRESTO. After ten years virtually all of
the radionuclide has leached from the soil by RESRAD, while PRESTO indicates that less
than half the radionuclide is lost from the soil. RAGS/HHEM indicates no change in soil
concentration over time.
2.1.7.2 Groundwater Contamination.
The groundwater pathway is where most multimedia models differ, and this is certainly the
case for the three models considered here. For all three models, relatively simple, generally
conservative approaches are used since the primary purpose of the calculations employed in
this report is to determine the radionuclide concentration in groundwater beneath or
immediately downgradient and adjacent to the site. No attempt is made to model groundwater
flow and transport in a complex setting or at a distance from the contaminated source.
RESRAD and PRESTO simulate flow and transport through the unsaturated zone in similar
fashions. Both models assume the following:
• No dilution occurs in transit
• Radionuclides decay as a function of half-life
Groundwater velocities are a function of infiltration rates, saturated hydraulic
conductivities and soil texture
• Radionuclide velocities are a function of groundwater velocities and
radionuclide-specific retardation factors
Radionuclides leaching from the contaminated zone is the source of groundwater
contamination for all three models. RAGS/HHEM employs the simplest leaching model. The
radionuclide concentration is calculated using the linear Freundlich equation and a dilution
factor to account for dilution and attenuation in the unsaturated and saturated zone. The
RAGS/HHEM equation takes the following form:
Cw = Cs/[(Kd + es/p) x DF]
where:
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Cw = radionuclide concentration in groundwater (pCi/L)
Cs = radionuclide concentration in soil (pCi/kg)
Kd = radionuclide distribution coefficient (L/kg)
S = fraction of water content (Lwater/Lpore)
0 = soil porosity (L pore/L soil)
p = bulk soil density (kg/L soil)
DF = dilution/attenuation factor
This is the basic approach recommended in EPA's Draft Guidance for Soil Screening Level
Framework (EPA 94). It simply estimates the concentration of the radionuclide in the soil
pore water using the distribution coefficient (Kd) and then applies a factor, DF, to account for
dilution and attenuation between the source and downgradient well.
As discussed previously, RESRAD is conservative in estimating the leachate concentrations
for each radionuclide, and allows high percentages of the radionuclides to reach the
groundwater. That, in turn, results in conservative estimates of radionuclide concentrations in
the groundwater.
In a similar fashion to RAGS/HHEM, RESRAD also uses a dilution factor. RESRAD,
however, explicitly derives the dilution factor based on the volume of water in the
contaminated plume, relative to the capture zone of the receptor well which is located at the
edge of the source. The dimensions of the contaminated plume are defined geometrically by
adding the vertical infiltration flux vector with the horizontal groundwater velocity vector
over the length parallel to the aquifer flow (i.e., diameter of the circular contaminated area).
The resolution of these two vectors will result in an interception point on the receptor well. If
this point falls at the midpoint of the well, contaminant concentrations in the groundwater are
reduced by 50%. If the interception point falls below the bottom of the well, no dilution is
assumed.
The leachate concentrations calculated by PRESTO are based on contact time assumptions,
which, under most circumstances, would allow smaller quantities of radionuclides to reach the
groundwater each year. This lower leach rate has two effects on the groundwater
concentration: an increase in relative loss through radioactive decay and a decrease in the
quantity of each radionuclide added to the aquifer each year. The increase in time required to
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maximize the radionuclide concentration in groundwater means that radionuclides with short
half-lives relative to their Kd values will decay before they reach the groundwater.
Table 2-7 shows the concentration in groundwater for several Kd values. The contaminated
infiltration water that contains the leached radionuclide is diluted into the water in the aquifer.
This dilution factor is obtained by dividing the radionuclide concentration that reaches the
well by the volume of water flowing through the cross-sectional area of the aquifer. The
dilution factor for PRESTO can be set approximately equal to the dilution factor for RESRAD
by setting the aquifer thickness equal to the well penetration depth.
Table 2-7 also shows the time of maximum groundwater concentration for each of the three
models. Data in this table suggest that the concentration of radionuclides in groundwater is
dependent on the Kd, and that the differences between the models become less as the Kd value
increases. It should be noted that no radioactive decay correction has been applied to the
groundwater concentration calculation, and that the Kd values do not correspond to any
specific radionuclide.
2.1.7.3 Surface Water
The radionuclide concentration in surface water is handled differently for all three models.
RESRAD assumes that the surface water is a pond, which dilutes the contaminated infiltration
water as it moves from the contaminated zone into the volume of the pond. The dilution
factor is based on the recharge area, or watershed, which is associated with the pond. The
dilution factor is the area of the contaminated site divided by the area of the watershed.
PRESTO calculates the radionuclide concentration in a surface water body by factoring in (1)
surface leaching and runoff and (2) subsurface flow leaching through the contaminated zone
and dilution. PRESTO assumes that the surface water body is a stream. To account for the
contribution of radionuclide contamination due to surface leaching and runoff, PRESTO
dilutes the quantity of radionuclide leaching and running off into the stream by the annual
stream flow at the point where the water is withdrawn. To account for the contribution from
subsurface flow leaching through the contaminated zone, PRESTO dilutes the quantity of the
radionuclide present in well water that is not used for other purposes (irrigation, drinking
water, etc.) by the annual stream flow.
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Table 2-7. Radionuclide Concentration in Groundwater (pCi/L)
Based on Distribution Coefficient (Kd)
KH
0
0.01
0.1
1
5
10
RESRAD Version 5. 19
pCi/L
678
647
460
118
27.5
14.0
Time of
Maximum
Concentration
0.7
0.7
1
4
16
31
PRESTO-CPG
pCi/L
78.9
81.5
99.3
73.2
29.3
16.1
Time of
Maximum
Concentration
808
808
808
814
839
870
RAGS/HHEM
pCi/L
10,000
9,090
5,000
909
196
99
RAGS/HHEM uses a model based on leaching and defines a dilution factor based on surface
area of the site compared to the recharge area similar to RESRAD.
2.1.7.4 Exposure to External Radiation
External radiation exposure to contaminated ground and the associated potential health risks
are derived by each code using fundamentally similar models. Given the radionuclide
concentration in soil, typically expressed in units of pCi/g, the radiation dose rate and cancers
risks are derived using EPA approved dose conversion factors (DCFs) and slope factors
(SFs). Dose conversion factors are expressed in terms of mrem/yr per pCi/g. Accordingly,
the product of the radionuclide concentration in soil with the DCF for external exposure yield
the dose rate to individuals standing on the contaminated soil, expressed in units of mrem/yr.
In a similar manner, the product of the SF, which is expressed in units of lifetime risk of
cancer/yr per pCi/g, with the radionuclide concentration in soil, yields the lifetime risk of
cancer to individuals residing on the contaminated soil. The EPA-approved DCFs are
presented in Federal Guidance Report No. 12 (EPA 93d) and the EPA-approved SFs are
provided in the Health Effects Assessment Summary Tables (EPA 92b).
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The primary differences between the three codes3 in modeling external exposure to
contaminated soil lies in the manner in which the models account for the following five
processes:
(1) Radioactive decay and progeny ingrowth,
(2) Correction factors for the geometry of the contaminated soil,
(3) Depletion of the contaminated soil horizon by environmental processes, such as
leaching and erosion,
(4) Corrections for shielding by clean cover material, and
(5) Adjustments for indoor occupancy and associated shielding effects.
The simplest model of the three considered here, RAGS/HHEM Part B, does not account for
the first four processes. As a result, it effectively assumes that an individual is continually
exposed to a non-depleting source term with a geometry that is an effectively infinite slab.
The concept of an "infinite slab" means that the thickness of the contaminated zone and its
aerial extent are so large that it effectively behaves as if it were infinite in its physical
dimensions. In practice, soil contaminated to a depth greater than about 20 cm and with an
aerial extent greater than about 1E4 m2 will create a radiation field comparable to that of an
infinite slab. For the purposes of this report, adjustments for clean cover are not needed since,
in all cases, it is assumed that the contaminated soil extends to the surface. The fifth process
is accounted for by the simple application of a shielding factor and indoor occupancy time
adjustment.
PRESTO provides for radioactive decay and explicitly accounts for the geometry and
depletion of the source and cover material, but its older versions do not provide for the
ingrowth of progeny.
RESRAD provides for these five processes in order to derive a more realistic—and as such, a
less conservative—estimate of the dose rate and risks from people located in areas with
contaminated soil.
3 There are additional differences that are revealed in a close examination of the documentation and listing of the
codes. However, these are not addressed in this overview comparison of the codes.
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2.1.7.5 Inhalation of Dust
The calculation of the radiological doses and risks from the inhalation of dust at a site can be
estimated from the radionuclide concentration in air of the respirable portion of airborne dust
(pCi/m3), the breathing rate (m3/yr), exposure time (yr), and either a dose conversion factor
(mrem/pCi inhaled) or an inhalation slope factor (lifetime risk of cancer/pCi inhaled). The
key to this calculation is determining the radionuclide concentration in airborne, respirable
dust.
Radiological risk assessment models employ several alternative methods for evaluating the
doses and risks from the inhalation of suspended dust, including empirically derived
suspension rates, resuspension factors, and dust loadings. A suspension rate, in units of
pCi/sec, is used to estimate the rate at which radioactivity becomes suspended in air and is
used primarily as input to an atmospheric transport model for use in deriving offsite
exposures. As a result, it is not entirely appropriate for the purposes of this report, where the
main concern is onsite exposures. The resuspension factor is an empirically derived transport
factor that relates the airborne contamination at a site (in units of pCi/m3) to the near-surface
contamination at the site (in units of pCi/m2). This parameter is used primarily at sites where
the contamination is surficial, such as that due to fallout. As such, it is of limited use at a site
where the soil is contaminated at depth, as with most of the sites addressed in this report. The
dust loading approach defines the airborne concentration of dust at a site (i.e., ng/m3) and
usually assumes that the radionuclide concentration in the dust is the same as that in the near-
surface soil at the site. Often an enhancement or depletion factor is applied to account for the
fact that, at some sites and for some radionuclides, the radionuclide concentration in the dust
can elevated (i.e., "enhanced") or diminished (i.e., "depleted") relative to the concentration in
soil. Seh (Seh 84) and Pet (Pet 83) discusses this process in depth.
All three models employ the dust loading approach. Accordingly, the key issue is the
selection of the most appropriate dust loading and enhancement or discrimination factor.
Input parameters allow adjustments for indoor versus outdoor exposures and for time spent
onsite. The main difference among the models is how each code treats the concentration of
the radionuclides in soil (i.e., the source term) as a function of time, as described in Sections
2.1.7.1 and 2.1.7.2.
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The processes by which H-3 and C-14 become airborne are different from those responsible
for the suspension of particulates. As a result, most codes model exposure to these
radionuclides differently. RESRAD includes special calculations for H-3 and C-14, where the
radionuclide concentration in air is not dependent on the dust loading. H-3 is transferred to
air by exhalation of water vapor from the ground and is diluted in air using a correction factor
based on the absolute humidity. The final exposure is multiplied by 1.5 to account for
absorption of water vapor through the skin. The concentration of C-14 in the air depends on
the volatilization rate of carbon from the soil, the size and location of the source area, and
meteorological dispersion conditions. For these calculations the volatilization rate replaces
the dust loading in calculating the radionuclide concentration in air.
2.1.7.6 Inhalation of Radon
The inhalation of radon and its decay products is a major contributor to total exposure when
radium isotopes are present in the soil. The methods used to derive the doses and risks from
the inhalation of indoor radon involve modeling the buildup of radon and radon progeny
indoors and then multiplying by an appropriate dose or risk conversion factor which relates
airborne concentrations of radon progeny to dose and risk. Though there is considerable
debate on the risk conversion factor for radon progeny, the Agency has adopted an approved
value for use in risk assessments. Accordingly, the key to assessing the risk to indoor radon is
the method used to model the buildup of radon indoors.
Generally, the most important contributor to indoor radon buildup is transport from soil to the
home. RESRAD employs a diffusion model based on empirically derived constants to
estimate the flux of radon into a home. Buildup is then based on the air turnover in the home
and the decay rate of radon and its progeny. RESRAD also accounts for contributions from
outdoor air and household use of water containing dissolved radon, but does not account for
advective flow.
RAGS/HHEM (as modified by ORIA) does not explicitly model the transport and buildup of
radon indoors. Instead, it employs an empirically determined relationship between the radon
concentration indoors and the Ra-226 concentration in soil. RAGS/HHEM calculates radon
concentration in air, both indoors and outdoors, assuming a simple relationship between the
national average natural radium background concentration in soil, i.e., 1 pCi/g Ra-226 (NCRP
76), and the average natural ambient radon concentrations in outdoor and indoor,
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i.e., 0.12 pCi/L (NCRP 76) and 1.25 pCi/L (EPA 92a), respectively. The RAGS/HHEM
relationship assumes that the indoor and outdoor radon concentrations are directly
proportional to the average Ra-226 concentration in the soil.
PRESTO-CPG does not include a pathway for inhalation of radon.
2.1.7.7 Ingestion of Soil
The calculation for the ingestion of soil is simply the total amount of contaminated soil
ingested over the entire exposure duration multiplied by the slope factor. The three models
differ only in the manner in which the activity is considered in the source term, as described
in Section 2.1.7.1.
2.1.7.8 Ingestion of Plants
The doses or risks from the ingestion of contaminated plants are derived as the product of the
radionuclide concentration in the edible portions of the vegetables (e.g., pCi/g), the ingestion
rate of the vegetables by individuals (kg/yr), exposure time (yr), and the ingestion dose
conversion factor (mrem/pCi ingested) or slope factor (risk/pCi). All three models include
exposure from ingestion of contaminated vegetables. However, the models differ in the
methods used to derive the radionuclide concentration in the vegetables as a function of time.
In general, vegetables become contaminated through root uptake of radionuclides contained
in the pore water of the soil in which plants are growing, uptake of contaminated irrigation
water, soil deposition from splashing, and direct deposition of suspended contaminated soil.
The contamination in the plant is removed by radioactive decay and food processing.
Accordingly, the level of contamination is a function of the level of contamination in soil and
in irrigation water, either of which can vary as a function of time, of the time between
harvesting and ingestion, and of the type of food processing which can remove the
contaminants. The doses and risks also depend on assumptions regarding the quantity of
contaminated vegetables ingested.
RESRAD includes root uptake, irrigation (overhead or ditch), and air deposition as potential
routes for contamination entering plants. Contaminated soil deposited on the leaves from
precipitation or irrigation is assumed to have negligible impact, since air deposited soil or dust
is usually washed off before the plants are consumed. RESRAD assumes that not all
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ingested plants are grown on the contaminated site. An adjustment factor accounts for the
area of the contaminated site, but with an upper bound assumption that no more than 50% of
the vegetables consumed will come from the site. RESRAD also includes correction factors
for radionuclide decay between harvest and consumption, and radionuclide removal due to
weathering of the plants. There is a foliage to food correction factor of 0.1 applied to fruits
and non-leafy vegetables (only 10% of the plant is consumed: See DOE 93a, page 183).
There are additional corrections for length of the growing season, wet-weight crop yield, air
deposition velocity of suspended particles, and fraction of contamination retained from air
deposition and irrigation.
PRESTO includes root uptake, irrigation (overhead only), and air deposition as potential
routes for contamination entering plants. Contaminated soil splashed onto plants by
precipitation and irrigation is not modeled. PRESTO includes a correction factor for the
fraction of consumed plants that are contaminated. In addition, PRESTO includes correction
factors for radionuclide decay between harvest and consumption, and radionuclide removal
due to weathering of the plants. The foliage to plant correction factor for fruits and non-leafy
vegetables is included. The additional corrections listed for RESRAD are also included.
RAGS/HHEM considers only root uptake in estimating the radionuclide concentration in
plants and it accounts for that uptake with a simple soil-to-plant transfer factor, Biv =
(pCi/g)plant/(pCi/g)soil. The decision to not include air deposition does not affect any
radionuclides because the increase in concentration from this route is not significant. The
decision to not include the irrigation pathway is only an issue when there is medium to heavy
irrigation using contaminated water for a radionuclide with a long half-life, a low Kd value,
and an insignificant contribution from external exposure.
RESRAD and PRESTO include special calculations for estimating concentrations of H-3 and
C-14 in plants. These calculations assume that a state of equilibrium exists among the
concentrations of H-3 and C-14 in all environmental media—air, water, food products, and
body tissues. This assumption may be overly conservative for a radioactively contaminated
site with a finite area, but may be applicable for an individual pathway, such as soil-to-plant
pathway (DOE 93a). For these calculations, the H-3 concentration in the plant is assumed to
be the same as that in the contaminated water to which the plant is exposed. Similarly, the C-
14 specific activity in the plant (i.e., pCi/g of C-14 per gram of carbon in the plant) is the
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same as that of the ambient CO2. In addition, RESRAD assumes a deposition velocity of
nearly 0 m/s for H-3 and C-14, while PRESTO uses 1 x 10"3 m/s, i.e., the deposition velocity
applied to all radionuclides.
2.1.7.9 Ingestion of Meat and Milk
The models used to derive the doses and risks from the ingestion of meat and milk are similar
to those used for vegetables; i.e., they involve the product of the radionuclide concentration in
meat and milk, the ingestion rate, and the ingestion slope factors. Calculation of the levels of
contamination in meat and milk are based on empirically-derived transfer factors expressed in
units of pCi/kg of meat or milk per pCi/day of the radionuclide ingested by cattle and milk
cows. The product of this transfer factor with the radionuclide activity in animal feed,
pasture, water, and incidental soil ingested daily yields the steady state radionuclide
concentration in meat and milk. Accordingly, the key to this calculation is the model used to
determine the radionuclide concentrations in soil, feed, pasture, and drinking water (inhalation
rarely affects the results). The specific activities in soil, feed, and pasture are modeled as
described above, and the activity in drinking water is a function of the activity in ground and
surface water. Ultimately, the activities in the feed, pasture, and water are functions of that in
the soil. Accordingly, differences in the codes used to model the activity in soil as a function
of time directly effects the results of vegetable, meat, and milk modeling.
All three models include calculations for estimating radionuclide concentrations in meat and
milk and the lifetime risk from their ingestion. One assumes that the meat consumed for these
scenarios is beef, but any type of meat (including game) can be modeled by putting in the
appropriate transfer factor from plant to meat or from plant to milk.
RESRAD includes ingestion of plants, ingestion of soil, and ingestion of water as possible
routes for radionuclide contamination of meat and milk. The radionuclide concentrations in
these three media are calculated as described in previous sections. The radionuclide
contamination in fodder is calculated using different corrections—for length of the growing
season, wet-weight crop yield, and air deposition velocity of suspended particles—than those
used for leafy vegetables, fruits, and non-leafy vegetables. The quantity of water and fodder
ingested by milk cows is different from the quantities consumed by beef cattle.
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PRESTO uses equations similar to RESRAD, but does not include ingestion of soil as a factor
in calculating the radionuclide concentration in meat. PRESTO allows different quantities of
water to be ingested by milk cows and beef cattle, but the amount of feed consumed by milk
cows and beef cattle are the same.
RAGS/HHEM includes ingestion of plants, soil, and water for estimating radionuclide
concentrations in meat and milk.
2.1.7.10 Ingestion of Water
The ingestion of water for these calculations has been limited to ingestion of groundwater.
Both RESRAD and PRESTO allow for a user specified fraction of the drinking water to come
from surface water for both humans and animals. The scenarios are limited to drinking
groundwater because this is the most conservative estimate of risk calculated using RESRAD
(i.e., For RESRAD, the radionuclide concentration in groundwater is always higher than the
radionuclide concentration in surface water). PRESTO calculations show that radionuclides
with high Kd values and long half-lives will have a surface water component from erosion in a
shorter time period (within the 1,000 year modeling period) than the groundwater component.
While human ingestion of surface water from a contaminated site is not considered a
reasonable scenario in most instances, animal ingestion of surface water is a plausible
scenario, and there may be increased risk from some radionuclides if surface water is used for
watering animals and irrigation instead of groundwater.
The concentrations in groundwater are calculated differently for each model. For example,
RAGS/HHEM uses a simple leaching model and a dilution/attenuation factor to calculate
radionuclide concentrations in groundwater. Other major differences among the models for
the groundwater pathway are discussed in the previous section on source terms.
2.1.7.11 Ingestion of Fish
RESRAD, PRESTO, and RAGS/HHEM address ingestion offish contaminated with
radionuclides. Because of the typically low radionuclide concentrations in surface water, as
well as the small quantities offish that are generally ingested by the average person, the fish
ingestion contribution to dose and risk is usually small, with notable exceptions.
The radionuclide concentration in fish is dependent on the radionuclide concentration in
surface water. The radionuclides are transferred from the water to the fish living in the water.
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Ingestion of vegetation and other aquatic creatures as well as direct transfer from the
contaminated water to the fish are assumed to be included in the water-to-fish transfer factor,
and to account for bioconcentration effects. The radionuclide concentration in surface water
is calculated differently for each model. These differences are discussed in the section on
source terms (Section 2.1.2.1).
2.2 CUMULATIVE POPULATION IMPACTS
This section describes the models, scenarios, and assumptions used in this report to perform
cumulative radiological impact assessments. The results of modeling the generic and
reference sites to determine population impacts appear in Sections 3.6 and 5.2, respectively.
Simply estimating the risks to RME individuals prior to and following cleanup does not
provide sufficient evaluation of a site's potential radiological impacts on public health. One
must also derive the cumulative impacts to the population in the vicinity of the site. For
example, suppose that a site is remediated such that the lifetime risk of cancer to an individual
assuming RME conditions is less than IxlO"4 and this level of risk is considered protective of
human health. Consider the situation in which there are one million people residing in the
vicinity of the site and that the average risk to these individuals is IxlO"6 per person per year
over 1,000 years. Although no individual is bearing a lifetime risk greater than IxlO"4, the
total number of potential cancers in the exposed population over the 1,000 years is (IxlO"6 per
person per year) x (106 persons) x (1000 years) = 1,000 cancers. A complete characterization
of the potential radiological impacts of such a site, and the adequacy of site cleanup, must also
address these types of cumulative health impacts.
2.2.1 Exposure Scenarios
A site and the surrounding area may be used for a variety of purposes. While the land-use
patterns may be expected to change over time, the exposures may be expected to persist until
the radionuclides at the site decay or are transported away from the environment most readily
accessible to humans. For many sites, the radionuclides are depleted from the soil very
slowly, creating the potential to cause exposures to nearby populations for many hundreds or
thousands of years.4 Due to the long time periods involved, it is difficult to predict how the
4 Depletion of radionuclides from soil can include radioactive decay, leaching, and erosion. For relatively
short-lived radionuclides, such as Cs-137, Sr-90, and Co-60 (half-lives of 30, 28, and 5.3 years, respectively),
radioactive decay will remove the radionuclides from the environment relatively quickly. Radionuclides with low
binding capabilities to soil, such as Tc-99,1-129, and tritium, will deplete rapidly due to leaching processes.
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land may be used in the future. Accordingly, any estimate of population impacts, and of
impacts averted as a result of cleanup, must postulate a broad range of future land-use
scenarios, including scenarios that may currently seem inappropriate.
For the above reasons, a range of scenarios was selected for use in deriving the potential
cumulative radiogenic cancers associated with contaminated soil at a site, including
assumptions which result in upper bound estimates. Specifically, notwithstanding a site's
current use, the analysis is based on the assumption that some day the site could be either
heavily populated or used for farming—either way, the groundwater could be used
extensively for domestic purposes. The specific population exposure pathways addressed
therefore include:
• Direct radiation from living on contaminated soil
• Inhalation of suspended dust
• Ingestion of crops raised on contaminated soil
• Ingestion of contaminated groundwater
• Exposure to indoor radon progeny.
2.2.2 Rationale for Excluding Selected Pathways from the Population Impact Assessment
The exposure pathways explicitly addressed in the population impacts assessment models
only address five pathways: direct radiation from contaminated soil, inhalation of suspended
dust, ingestion of plants contaminated by root uptake, ingestion of groundwater, and indoor
radon. The models do not explicitly include soil ingestion, meat and milk ingestion, or the
ingestion of food items contaminated as a result of the irrigation pathways. These pathways
were excluded because they do not significantly contribute to the population doses for the
radionuclides and reference sites addressed in the report. Table 2-8 shows the relative
contribution for each of the key radionuclides to risk at the generic site for all pathways.
Most other radionuclides found at many Federal facilities (primarily isotopes of uranium, thorium, radium, and
plutonium) bind tenaciously to soil and therefore represent a potential source of exposure for long periods of time.
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Table 2-8. Relative Pathway Contribution to Risk
Pathway
Fractional Contribution to Risk by Isotope
Cs-137+D1
Pu-239
Ra-226+DJ
Th-230
U-238+D7
Water Independent Pathways
External radiation*
Dust inhalation
Indoor radon
Plant ingestion
Meat ingestion
Milk ingestion
Soil ingestion
0.87
0
0
0.03
0.07
0.02
0
0
0.59
0
0.28
0.02
0
0.11
0.12
0
0.88
0.01
0
0
0
0.09
0.02
0.63
0.01
0
0
0
0.01
0.01
0
0
0
0
0
Water Dependent Pathways
Water ingestion
Fish ingestion
Indoor radon
Plant ingestion
Meat ingestion
Milk ingestion
Total
Fraction Captured by
Selected Pathways
Fraction Missed
0
0
0
0
0
0
1.0
0.9
0.1
0
0
0
0
0
0
1.0
0.87
0.13
0
0
0
0
0
0
1.0
1
0
0.22
0.01
0.02
0.01
0
0
1.0
0.97
0.03
0.94
0
0
0.02
0
0.01
1.0
0.96
0.04
* Bold pathways were included in the population impact assessment.
1 Includes short-lived progeny.
The results reveal that, for these radionuclides—which are representative of the principal
radionuclides modeled at the reference sites—the pathways included in the population dose
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model capture between 87% and 100% of the risk. Consideration is being given to revising
the population impact assessment models to account for soil ingestion because about 10% of
the Pu-239 risk is due that pathway.
Contamination of crops by the deposition of resuspended particulates is not explicitly
addressed in modeling the vegetable ingestion pathway. The following analysis
demonstrates—for the radionuclides of primary concern at contaminated
sites—contamination of crops by dust resuspension and deposition is not an important
contributor to risk relative to the root uptake pathway.
The environmental transport factors (ETF) were calculated for eight radionuclides (Co-60,
Sr-90, Cs-137, Ra-226, Th-232, U-238, and Pu-239) for root uptake and foliar deposition to
compare the relative magnitudes of the ingestion of the radionuclides due to these two
mechanisms of plant contamination. Calculations were made using the formulas and
parameters specified in Appendix D of the users manual for RESRAD (DOE 93a). The results
are expressed as the ratio ETF2/ETF,, where the subscript 2 represents foliar deposition and
the subscript 1 represents root uptake.
Table 2-9 lists the ETF ratios. Since the ETF2 value is constant for non-gaseous
radionuclides, the changes in the ratios are due to variations in root uptake for the listed
radionuclides. The results of this comparison show that even with a large range of
radionuclide root uptake values, including those with the smallest reported values, foliar
deposition is not a significant contributor to the plant pathway.
Table 2-9. A List of ETF2 /ETF1 for Eight Radionuclides
Radionuclide
Co-60
Sr-90
Cs-137
Ra-226
Th-232
U-238
Pu-239
Ratio
8.6E-05
2.3E-05
1.7E-04
1.7E-04
6.9E-03
2.8E-03
6.9E-03
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2.2.3 Future Land Use Scenarios
Four future use demographic patterns are considered in deriving the long term impacts
associated with radioactively contaminated soil: rural, intermediate, suburban, and "most
likely". In the rural demographic setting, one assumes that the population density is 10
persons/km2, with and without intensive farming. In the intermediate demographic setting,
the population density is assumed to be 100 persons/km2, with and without farming. In the
suburban setting, the population density is assumed to be 1,000 persons/km2, without farming.
Finally, the "most likely" scenario for each reference site adopted the population density of
the corresponding actual site upon which it was based, and rounded off to the nearest
hundred/km2. Farming was assumed for densities less than 300 persons/km2.
These six scenarios capture the range of site conditions that may be anticipated over the next
1,000 years at most sites which may fall within the scope of the rulemaking. Appendix D
presents a summary of demographic and agricultural information characterizing many of the
sites that fall within the scope of the rulemaking. Table 2-10 summarizes the population
density distribution at many of these sites. The population density scenarios of 10, 100, and
1,000 persons/km2 generally envelop the actual conditions at these sites. Two sites, the
Nevada Test Site and Maywood fall outside the envelop. The site specific analysis provided
in Chapters 5 and 6 address these issues in greater detail.
2.2.4 Time Periods of Concern
Depending on the half-life of the radionuclide and its daughters, and the rate at which the
radionuclides deplete from the site, the potential cumulative impacts of a site can extend over
hundreds to thousands of years. In addition, notwithstanding the depletion rate of the
radionuclide at a site, there is a degree of uncertainty associated with the appropriate time
period over which the impacts should be integrated. As a result, cumulative impacts should
be determined for three time periods: 100, 1,000, and 10,000 years.
The alternative pathways and time periods are explicitly addressed in order to support EPA's
consideration of future land-use scenarios and time periods of interest for the rulemaking. A
computer model was developed to facilitate the performance of the calculations. A detailed
description of the model and the results of the analyses are provided in Appendix E. The
following briefly describes the model through the use of example calculations.
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Table 2-10. Population Density by County
Within a Circle of 80 Km Radius for DOE/DOD Sites
Site
Aberdeen
-20 km NE
Idaho
Hanford
Maywood
Nevada Test
Oak Ridge
Paducah
Portsmouth
Rocky Flats
-27 km NW
Savannah River
-25 km NE
Weldon Spring
-40 km W
Pop. Density
Within 80
Km Radius
(Ind/km2)
-
10
23
_
0.5
59
35
58
110
55
-
County
Harford
Bonneville
Benton
Bergen
Nye
Knox
McCracken
Pike
Boulder
Aiken
Barnwell
St. Charles
1990
Population
182,132
72,207
112,560
825,380
17,781
335,749
62,879
24,249
225,339
120,991
20,293
212,751
Area
(km2)
1,160
4,766
4,442
614
46,786
1,311
650
1,147
1,922
2,828
1,445
1,445
Pop.
Density
by County
(Ind/km2)
157
15
25
1,344
0.4
256
97
21
117
43
14
147
Note: The population density within an 80 km radius around a reference light water commercial power
reactor is assumed to be 117±150 persons per km2.
2.2.5 Model Description
The calculation methodology is based loosely on RAGS/HHEM. Furthermore, the model
assumes that the cumulative population impacts are directly proportional to the total inventory
of radioactivity at a site. Thus, for each site, results can be derived in terms of impacts per
curie for each radionuclide, pathway, and time period of interest. Once the soil volume and
its radionuclide content are determined for each site, it is a simple matter to determine the
impacts caused by the site if the contaminated soil is left in place, or averted if all or a portion
of the contaminated soil is remediated.
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The assumption that impacts are directly proportional to the inventory is based on the fact
that—as long as the population density and land use at the site and in the vicinity of the site is
uniform—the time integrated cumulative population impacts are the same whether the activity
is confined to a small area, (resulting in relatively large individual doses to a small
population), or spread over a large area, (where the corresponding smaller doses are delivered
to large populations).
The model is also based on the assumption that radionuclides are depleted from the soil only
by radioactive decay and downward migration. The model does not address surface erosion
or runoff. This effectively increases the residence time of the radionuclides in the soil at the
site and thereby increases the time of integrated impacts for persons onsite. However, it
neglects offsite impacts that may be associated with radionuclides transported offsite. The
potential significance of this assumption is assessed as part of the sensitivity and uncertainty
analysis for the reference sites analyzed in Section 6.
Appendix E describes in detail the method used to calculate the cumulative population
impacts for each pathway. The methodology is illustrated in the remainder of the present
chapter using a hypothetical site with a contaminated region of area 3xl06 square meters. Our
hypothetical site contains U-238 at an average concentration in soil of about 210 pCi/g, Th-
230 (350 pCi/g), and Ra-226 (350 pCi/g). (These radionuclides are not assumed to be in
secular equilibrium.) For each of the five pathways discussed in this simple example,
however, we shall consider only the single radionuclide that dominates risk.
2.2.5.1 External Radi ati on
Individuals located on or near contaminated soil would receive doses of direct external
radiation. The following illustrates the estimation of population cancer dose and risk due to
external radiation from Ra-226 in soil.
For this example, the depth of contamination is assumed to extend from about 9 meters
extending down to the water table. For the purpose of calculating the baseline external
radiation dose and health impacts, we assumed that—at some time in the future—the site is
occupied with a population density of 1,000 persons per km2, which is close to an urban
population density. The population density in the vicinity of the site may be currently lower
than this, but given the time period of concern, one can assume that the population density
could increase to 1,000 persons per km2 and remain at that level. Since the potential
cumulative public health impacts are directly proportional to the assumed population density,
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these impacts can be readily adjusted for alternative assumptions regarding population
density.
The average Ra-226 concentration in the contaminated soil is 350 pCi/g (Natural background
levels are about 1 pCi/g.) The Ra-226 in the soil generates several decay products which are
relatively short-lived and are therefore assumed to be in equilibrium. This means that the
specific activities of all decay products are the same as that of the parent. Hence, every time
there is a decay of a Ra-226 atom, there is also a decay of each short-lived member of its
decay chain. Individuals in the contaminated area are exposed externally to the gamma
radiation emitted from the soil.
Due to the gradual depletion of the radioactivity in the soil—caused by radioactive decay and
downward leaching of the contaminants—the rate of exposure slowly declines over time. The
method used to estimate the dose to the population requires integration of the dose over t
years; in this example 10,000 years is assumed. This is equivalent to calculating the dose
imparted to a typical member of the population in year 1, in year 2, in year 3, etc. out to year
10,000, and then summing the doses. In each succeeding year, the dose is a little smaller due
to depletion of the source. Since we assume there are 1,000 persons per km2 at the site and
the site is 3xl06 m2, 3,000 persons are exposed at any time. Hence, if the dose rate were 1
mrem/year per person for the first year, the cumulative population dose would be (1
mrem/year) x (0.001 rem/mrem) x (3000 persons) = 3 person-rem per year.
If the Ra-226 were extremely long lived and did not deplete from the soil significantly over
10,000 years, the integrated cumulative population dose over 10,000 years would be 30,000
person-rem. However, Ra-226 has a 1,600 year half-life and does leach from the soil,
resulting in a gradual reduction in the annual individual dose rate. As a result, the 10,000
year integrated dose is somewhat less than 30,000 person-rem.
The population dose rate at time 0 can be estimated as follows:
POPDOS(0)Ext = RSC x DCFExt x SD x A x N
where:
POPDOS(0)Ext = population dose rate from direct radiation (person rem/year) at
time 0
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RSC = photon-emitting radionuclide soil concentration (pCi/g) at time
of cleanup (t=0)
DCFExt = external dose conversion factor (mrem/yr per pCi/cm3), assuming
infinite thickness and depth of contamination; from: Federal
Guidance Report No. 12 (EPA 93d)
SD = soil density (g/cm3)
A = contaminated zone area (m2)
N = assumed population density (persons per m2)
Assuming RSC = 350 pCi/g, A= 3xl06 m2 and N= 0.001 persons/m2, and with DCFExt = 7.0
mrem/yr per pCi/cm3 (EPA 93d), the population dose rate at time 0 from Ra-226+D (radium
and its short-lived progeny) in soil is:
POPDOS(0)Ext = 1.2xl04person-rem/yr
This dose rate can be assumed a constant value over the first year due to the long half-life of
Ra-226 and the slow rate at which it is depleted from the soil. Accordingly, the total number
of potential cancers produced in the population in year 1 by external radiation, POP(0)Ext, is
then computed as the product of POPDOS(0)Ext and EPA's dose-to-cancer incidence risk
conversion factor of 6.2xlO"4 cancers per person-rem (EPA 89a):
POP(0)Ext = POPDOS(0)Ext x 6.2xlO-4risk/rem
For this example, POP(0)Ext is seven total (fatal plus nonfatal) cancers for the first year of
exposure. Note that with minor modification of the equation, [DCFExt x 6.2xlO"4 risk/mrem]
could be replaced with the external slope factor, SFExt. The derivation of the potential cancers
derived in this report actually uses the July 1994 slope factors.
In successive years, the total number of expected cancers in any given year can be computed
as:
POP(t)Ext = POP(0)Extx exp-(DFlx<>
where:
POP(t)Ext = population cancer rate at time t years
DF1 = soil depletion coefficient (yr"1)
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In this model, two processes are responsible for depletion: radioactive decay and downward
leaching migration.
The soil depletion coefficient is defined as:
DF1 = [V/(MDxR)] + X
where:
V = rainwater infiltration velocity (m/yr)
R = retardation factor (unitless);
MD = soil mixing depth (m)
A = radioactive decay constant (yr"1). For Ra-226, the half-life is
1,600 years, and therefore X = 4.3xlO"4 per year.
The soil depletion coefficient may be thought of as the fraction of the radioactivity that is in
the contaminated zone and contributes to the external radiation exposure but is depleted from
the soil or undergoes radioactive decay per unit time.
The leaching component of DF1 may be obtained from a first order compartment model for
the leaching of contaminant from the soil. Depletion by leaching may be visualized, for our
example, as Ra-226 atoms mixing with rainwater to a soil depth MD, with some of that newly
contaminated water percolating downward but being replaced by fresh rainwater. The
velocity of the Ra-226 atoms through soil is much slower than that of the water because of the
tendency of radium ions to bind to the soil. The retardation factor accounts for this process.
Note that once the Ra-226 atoms are transported below about 15 cm, they are far enough
below the surface to be shielded by the overlying soil, and therefore no longer contribute to
the external dose.5
The retardation factor, R, is of standard form,
R 1 + [SDxKd/0]
5 In this simple model, the decay products of Ra-226 are assumed to be in continual equilibrium and are
depleted at the same rate as their parent. Such simplifications are applied with caution because radionuclides
with long-lived decay products and high binding coefficients may continue to deliver external exposures long
after the parent has been depleted from the surficial soil. Assuming full equilibrium at time zero is appropriate
for Ra-226, even if it is not in fact the case at a given site, because its longer lived daughter, namely Pb-210 (half-
life = 22 years), does not contribute significantly to external exposure. In addition, in light of the long integration
period, assuming equilibrium at time zero does not invalidate the approach because, in a relatively short period of
time compared to the integration period, Pb-210 will equilibrate.
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where:
Kd = radionuclide- and soil-specific distribution coefficient (cm3/g)
SD = soil density (1.6 g/cm3)
6 = volumetric water content (unitless)
FortheRa-226 example, V=1.5 m/yr, R = 3,500, MD = 0.15 m and X = 4.3xlO'4 per year.
Therefore, DF1 = 3.2xlO'3/yr.
To obtain POPExt.TOT, the total number of cancers expected in the population over an assumed
exposure duration, POP(t)Ext is integrated over the exposure interval. The result of the
integration process (assuming a 10,000 year exposure duration) is:
POPExt.TOT = POP(0)Ext/e-(DFlxt) dt
POP(0)Ext x [ 1 - e-(DF1 x l)] / DF1
= 2,250 cancers
2.2.5.2 Dust Inhalation
Individuals living onsite can receive internal exposure due to the inhalation of airborne dust
contaminated with radionuclides. For this example, it is assumed that the risk for this
exposure pathway is dominated by Th-230—initially at a concentration of 350 pCi/g—which
becomes airborne due to wind erosion and mechanical processes.6
The equation used to derive the population cancer risk for the first year of exposure to Th-230
in inhaled dust is:
POPInh = RSC x DL x IR x A x SF x N
where:
POPInh = population cancers induced per year from inhalation of Th-230 in dust
(cancers/yr)
6 In this example, the decay products of Th-230, namely Ra-226 plus its decay products, are ignored. In our
actual model, the Bateman equations were used to derive daughter ingrowth. An alternative approach is to assure
that Ra-226 plus all its decay products are also present for integration periods of 1,000 and 10,000 years. For
sites without Ra-226 at time zero, this tends to overestimate the 1,000-year integrated dose since Ra-226 will
reach only about 35% equilibrium in 1,000 years. For 10,000 years, this assumption does not significantly
overestimate the dose. For the 100-year integration case, Ra-226 ingrowth can be ignored since it will not grow
in significantly over this time period.
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RSC = radionuclide soil concentration (pCi/g)
DL = average annual dust loading (jig/m3)
IR = inhalation rate (m3/yr)
A = contaminated zone area (m2)
SFinh = inhalation cancer slope factor (cancer risk/pCi)
N = population density (persons/m2).
For the present example, the following assumptions were made: (1) the time-averaged
airborne dust loading (DL) is 100 |ig/m3, a typical value for outdoor dust loadings (NRC 92b);
(2) dust is contaminated at the same level as the soil; (3) IR = 8,000 m3/yr; (4) A = 3xl06 m2;
and (5) N = 0.001/m2. Substituting these values into the above equation, and using Th-230
SFinh = 2.9xlO-8 risk/pCi, yields:
POPInh = 0.024 cancers committed due to the first year of exposure
As with external radiation exposure, the radionuclide concentration in the soil slowly
decreases, as do the exposure rate and associated cancer induction rate. For thorium, the soil
depletion factor (DF2) is l.lxlO'Vyr, assuming V = 1.5 m/yr, MD = 0.15 m , R = 100,000 and
A = 9.0xlO'6peryear.
The potential number of cancers in the population over 10,000 years is computed as:
POPInh.TOT = (0.024 cancers/yr x [1 - exp-(DF2xt)]) / DF2
(0.024x[l-0.33])/l.lxlO-4
= 146 cancers
In this model, we assume that removal of radionuclides from surficial soil is by leachate
migration and radioactive decay. Once the radionuclides are transported to below the mixing
zone, we assume that they are no longer available for suspension.
2.2.5.3 Crop Ingestion.
The direct radiation and dust inhalation exposure scenarios are based on the premise that the
site will eventually be heavily occupied. For many sites, a more likely scenario is that the
sites will be used for agricultural purposes. Under this scenario, the population density is
reduced to rural conditions, typically less than 10 persons per km2, and the land is used to
grow crops which are sold commercially.
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In this scenario, we assume the site is used to grow vegetables and the productivity of the site
is 0.716 kg/m2 per year (EPA 89a). Accordingly, for the example site, which is 3xl06 m2 in
area, 2.15xl06 kg/yr of vegetables are produced. These vegetables are assumed to be
contaminated with radionuclides as a result of root uptake from the contaminated soil. For
our hypothetical site, the radionuclide of greatest concern is Ra-226.
The soil-to-plant transfer factor for Ra-226 is assumed to be 6.42xlO"4 pCi/g fresh weight of
vegetable per pCi/g dry weight of soil (EPA 89a). Accordingly, in the first year at the
example site, the Ra-226 concentration in the crops is estimated to be 0.22 pCi/g—i.e., (350)
x (6.42xlO"4 ). Assuming that all of the crops are consumed, the total numbers of potential
cancers induced by the ingestion of vegetables is the product of the total number of pCi/yr
ingested times the slope factor for Ra-226, as follows:
POPIng = RSC x PR x A x Biv x SFIng
where:
POPIng = population cancer induction rate (cancers per year) for the first year due
to the ingestion of vegetables grown in contaminated soil
RSC = radionuclide soil concentration (pCi/g)
PR = production rate of vegetables (assumed to be 0.716 kg/m2-yr)
A = contaminated zone area (m2)
Biv = soil-to-plant transfer factor (dimensionless)
SFIng = ingestion cancer slope factor (cancers/pCi ingested). For
Ra-226+D, the ingestion slope factor is 1.2xlO"10 cancers per pCi
ingested (EPA 92b)
Substituting values:
POPIng = 0.058 cancers for the first year of exposure
And the 10,000-year integrated population risk is:
POPIng.TOT = (0.058 cancers per year x [1 - exp-[DF1 xt)]) / DF1
= (0.058 cancers per year) / 9.1xlO"4 per year
= 64 cancers
The population density does not explicitly enter the calculation, but the number of people
potentially affected is accounted for with the assumption that all the contaminated crop is
consumed.
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Consideration is given to including contamination and risks resulting from the use of
contaminated groundwater for irrigation and foliar deposition from suspended dust.
However, the analyses sketched in Section 2.2.2 reveals that, for the radionuclides of interest,
the irrigation pathway and foliar deposition pathway are insignificant when compared to the
root uptake and groundwater ingestion pathways.
2.2.5.4 Groundwater Ingestion
Radionuclides contained in the surficial soil will migrate downward until they reach an
aquifer, where they are available as well water. Though the aquifer beneath a site may not be
currently used as a drinking water supply, in light of the time periods of interest, and as long
as the water is of adequate quality, it is appropriate to assume that the groundwater may be
consumed at some time in the future.
The population impacts associated with the consumption of contaminated groundwater are
modeled assuming that the radionuclides in the surficial soil are migrating downward at the
velocity of the infiltrating rainwater—assumed to be 1.5 m/yr in this example—divided by the
retardation factor for the radionuclide of interest. U-238 is the limiting radionuclide. Its
retardation factor is assumed to be about 700, which means that the downward effective
velocity is about 0.002 m/yr. The approximate time it takes for the contaminants to reach the
aquifer depends simply on the thickness of the uncontaminated unsaturated zone. For
example, if the uncontaminated unsaturated zone is 10 meters, the uranium would reach the
aquifer in about (10 m)/(0.002 m/y) = 5,000 years. If the thickness of the uncontaminated
unsaturated zone is only 1 meter, the uranium would reach the aquifer in about 500 years.
Once the radionuclides reach the aquifer, they are available to be withdrawn for domestic and
agricultural purposes. The fraction of the contaminated groundwater that is withdrawn
depends entirely on the site-specific conditions—which are difficult to predict far into the
future. To ensure that the impacts are not underestimated, the analysis assumes that 50
percent of the groundwater in the region is withdrawn for domestic and agricultural purposes.
(Hence, 50 percent of the radionuclide activity that reaches the aquifer is withdrawn). For the
drinking water pathway, it is assumed that 1 percent of the withdrawn water is consumed
(based on data provided in the Water Encyclopedia), (Van 90). Note, this approach to
calculating the population impacts from groundwater consumption does not require specific
consideration of the population density or the specific location or size of the exposed
population.
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The potential cancer induction rate, at time t, from the drinking of groundwater may be
described by:
POP(t),
GW
-•I
where:
Inv(O)
T
FR
V
CD
R
DF3
fl
£2
0, for t < T
Inv(O) x e-DF3(t-T)x FRx e" x
f 1 x f2 x SFIng, for t > T
inventory of contaminant at site at time t = 0 (pCi)
transit time from contaminated zone to water table
fraction of inventory leached from contaminated zone each year
V / (CD x R)
infiltration velocity of the rainwater
thickness of the contaminated zone
retardation factor
[V / (CD x R)] + A
fraction of leachate withdrawn (0.5)
fraction of withdrawn water consumed (0.01)
ingestion slope factor (cancers/pCi ingested)
radioactive decay constant (1/yr)
This assumes that at time t, the amount of radionuclide remaining in the contaminated layer,
Inv(t), is given by [Inv(O) x e'DF3(t'T)]; that the rate at which leachate leaves the contaminated
zone at time t is [Inv(t) x FR]; that the rate at which leachate enters the aquifer at time t is
[Inv(O) x FR x e"*1 x e"DF3(t"T)], where the temporal shift (t-T) accounts for the delay between
leaching of the contaminant and its entry into the aquifer, and the factor e"*1 describes the
decay of the radionuclide over time; and that the contaminant is pumped out of the aquifer
soon after it enters the aquifer.
For this example, the U-238 concentration in the soil is 210 pCi/g. The first step in deriving
the impacts is determining the initial total inventory of U-238 in the soil at time t = 0, as
follows:
Inv (0)
(210 pCi/g)(3.Ox 106 m2)(9 m)( 1.6x 106 g per m3)
9xl015pCi
For simplicity, the contaminated soil is assumed to extend down to the water table. As a
result, the aquifer is contaminated at time zero.
Review Draft - 9/26/94
2-58
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Accordingly, the total amount of U-238 transported to the aquifer in the first year is (9xl015
pCi) x (2.4xlO"4 per year) = 2.0xl012 pCi. Assuming that one half of this water is withdrawn
and 1 percent of that is consumed, the total amount of U-238 consumed is l.OxlO10 pCi.
Using a slope factor of 2.8xlO"n cancers per pCi ingested (EPA 92b), the total number of
cancers associated with the ingestion of U-238 in groundwater in the first year is about 0.28.
In each succeeding year, the quantity of U-238 available for consumption declines slightly
due to depletion of the source by radioactive decay and leaching. The leach rate is 2.4xlO"4
per year and the decay rate is 1.55xlO"10 per year. Accordingly, the depletion rate (DF3) is the
sum of the two, or 2.4xlO"4 per year.
The total number of cancers over 10,000 years from groundwater ingestion is therefore
estimated as follows:
POPGW.ToT = 0.28 per year x [1 - exp'(DF3xt)] / 2.4xlQ-4 per year
0.28 x 0.9/2.4xlQ-4
= 1,050 cancers
Though U-238 has a series of decay products, only the first two short-lived decay products
are assumed to be present at time zero. This situation could occur at a depleted uranium site.
The third daughter of U-238, U-234, has a half-life of 2.5xl05 years and therefore does not
grow in significantly, even over a 10,000 year integration period. As a result, U-234 and its
decay products are ignored if it is known that they are not present initially at a site. If U-234
is present, it is treated as a separate radionuclide, which may or may not include its chain of
decay products.
2.2.5.5 Indoor Radon
Individuals residing on contaminated property will be exposed to indoor radon and its
progeny if the soil is contaminated with Ra-226. The method used to estimate the exposures
and associated health impacts on the population from indoor radon is based on the
approximation that, on average, the indoor radon concentration is 1.25 pCi/L per pCi/g of Ra-
226 in soil. This is an empirical relationship observed to apply to Ra-226 naturally occurring
in the environment (EPA 92a) and to typical homes.
The 1.25 pCi/L per pCi/g relationship translates to 4.62E-5 lifetime risk of cancer per year per
person per pCi/g of Ra-226 in soil. This assumes 98.3 pCi/L per WL, 0.5 equilibrium
fraction, 51.56 WLM per year, an average indoor occupancy factor of 0.6 and a risk
Review Draft - 9/26/94 2-59 Do Not Cite Or Quote
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coefficient of 2.36E-4 risk per WLM. The risk factor is based on the supporting
documentation in the Radon Citizen's Guide and the occupancy factor is based on the
Exposure Factors Handbook (EPA 89a).
The cancer induction rate will decline each succeeding year due to depletion of Ra-226 in soil
by decay and leaching with a depletion rate of DF4.
The cancer rate, at time t, from indoor radon may be described by:
= RSCxe'(DF4xt)x AFx(4.62E-5 risk per pCi/g) x A x N
where:
RSC = radionuclide soil concentration (pCi/g)
A = contaminated zone area (m2)
N = population density (persons per m2)
AF = foundation depth adjustment factor
DF4 = [V / (ED x R) + X]
V = rainwater infiltration velocity (assumed to be 1.5 m/yr)
ED = effective depth over which radon can diffuse into a home (m)
R = retardation factor (assumed to be 3,500 for Ra-226)
X = radioactive decay constant (1/yr). For Ra-226, X = 4.3xlO"4 per
year
ED, the effective depth over which radon can diffuse into a home, was assumed to be 5
meters. Diffusion analyses indicate that the nominal effective depth for radon diffusion in soil
is about 4 to 5 meters (RAE 92). Once the top 5 meters of soil contamination is depleted,
exposures to indoor radon cease. Note that if 1 m were used instead of 5 m, DF4 would
increase from S.lxlO"4 to 8.6xlO"4 per year, reducing the impacts by less than a factor of 2.
For sites where the thickness of the contamination is less than 5 meters, the Ra-226
concentration is reduced by dividing the actual thickness of the contaminated zone by 5. This
was not necessary in this example because the thickness of the contaminated zone is greater
than 5 meters.
The total exposed population is 3,000 people (i.e., 0.001 persons per m2 multiplied by 3xl06
m2). In the first year, cancer induction due to indoor radon at the site is 49 cancers (i.e., 350
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pCi/g multiplied by 4.62xlO"5 cancers/year per pCi/g multiplied by 3,000 people). DF4 =
8.8xlO"5 + 4.3xlO"4 = S.lxlO"4 per year. Therefore, the total cumulative health impacts over
10,000 years from indoor radon inhalation at the example site is:
POP^.TOT = 49 x [l-exp-(DF4xt)]/ S.lxlO'4 per year
= 4.7xl04 cancers
2.2.5.6 Pathways Combined
The impacts from each pathway are summed except for the high population (suburban)
scenario. In this case, the impacts from each pathway cannot be simply summed in order to
determine the total impact from multiple pathways because a site cannot simultaneously have
a high population density (1,000 persons per km2) and also be used as a farm. The high
population density scenario is based on the assumption that the site has a continuous resident
population density of 1,000 persons per km2, which maximizes the impacts from direct
radiation, dust inhalation, and indoor radon exposure, but no crops are grown in the
contaminated soil. Presumably some individuals in a suburban setting have a backyard
garden, but for the population as a whole, a large fraction of the fruits and vegetables are not
obtained from backyard gardens. For this reason, the crop ingestion pathway is not included
in the suburban scenario.
The farm scenario is based on the assumption that the site has a low population density of
either 10 or 100 persons per km2 but has a high crop production rate (0.716 kg/m2-yr). In
both cases, the groundwater is assumed to be heavily used (i.e., 50% of the groundwater flow
is used for domestic purposes). Table 2-11 summarizes the pathways included in the three
demographic scenarios.
Review Draft - 9/26/94 2-61 Do Not Cite Or Quote
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Table 2-11. Pathways Included in the Suburban and Rural
Scenarios Used to Derive Cumulative Population Dose
Pathway
External radiation
Dust inhalation
Indoor radon
Plant ingestion (root uptake)
Plant ingestion (irrigation)*
Meat ingestion*
Milk ingestion*
Soil ingestion*
Water ingestion
Fish ingestion*
Suburban Scenario
Yes
Yes
Yes
No
No
No
No
No
Yes
No
Rural and Intermediate
Demographic Scenarios
Yes
Yes
Yes
Yes
No
No
No
No
Yes
No
* These pathways were not explicitly included because the sensitivity analysis showed them to be
insignificant contributors to the cumulative population impacts for the radionuclides of concern.
Review Draft - 9/26/94
2-62
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3. Assessment of Modeling Parameters and Capabilities
This chapter applies the models, exposure scenarios, and assumptions described in Chapter 2
to individuals and populations postulated to take residence at a hypothetical generic test site.
Section 3.1 evaluates individual risks and Section 3.2 evaluates cumulative population
impacts at the generic site. The evaluation of individual risks at the generic site is designed
to:
1. Intercompare the doses and risks to individuals as derived using the three
selected models (RESRAD, PRESTO, and RAGS/HHEM). The purpose of this
intercomparison is to evaluate the performance of the models and gain insight
into the advantages and limitations of each of the models. These comparisons
are also used to select a model to evaluate the risks to individuals at the
reference sites.
2. Evaluate the sensitivity of the results of the models to a range of alternative
assumptions regarding specific characteristics of the generic site. The purpose
of this evaluation is to identify those key site parameters which can
significantly impact the results for specific radionuclides and pathways. This
information is used to help ensure that the key site parameters are properly
considered in the development of the reference sites (e.g., if the thickness of the
contaminated zone or depth to aquifer is found to be especially important for a
given radionuclide, these site parameters are given added attention at those
reference sites that contain that radionuclide).
3. Evaluate the uncertainty in the risks per pCi/g for the individual exposed under
RME conditions at the generic site. The purpose of this exercise is to assess the
degree of conservatism inherent in the definition of the exposure scenarios
provided in Chapter 2. As discussed in Chapter 2, the individual exposed
under RME conditions is defined in terms of a set of occupancy factors, living
and eating habits, and slope factors which result in conservative, but not
unrealistic, doses and risks. This exercise will help to provide a level of
assurance that the exposure scenarios have been properly defined.
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The evaluation of the cumulative population impacts at the generic site is intended to evaluate
the performance of the bounding population model for the radionuclides of interest at the
reference sites. The population impact assessment model described in Section 2.2 employs a
number of simplifying assumptions. Through the application of the model to the generic site,
we are better able to determine whether the model and assumptions are reasonable and
whether the model can be used with confidence to assess the potential cumulative population
impacts at the reference sites.
3.1 GENERIC TEST SITE: INDIVIDUAL RISKS
3.1.1 Derivation of Generic Test Site Risk and Dose Factors
A risk factor is defined in terms of the assumed linear relationship between a given
concentration of a radionuclide in soil at a site and the risk to individuals who may reside or
work at the site. For each radionuclide and site, a risk factor is expressed in terms of lifetime
risk of cancer incidence per pCi/g of the radionuclide in soil.
Dose factors define the relationship between a given concentration of a radionuclide in soil
and the committed effective annual dose equivalent (CEDE) to individuals who may reside or
work at the site. For each radionuclide, dose factors are expressed in terms of mrem/yr per
pCi/g.
In this report, risk and dose factors are obtained for two conceptually different kinds of sites:
a generic test site described by a standard set of default modeling parameters, and a group of
"reference" sites intended to represent different categories of real sites. The present chapter
considers risk factors for the generic test site—Chapters 4 and 5 of this report compute risk
factors for the reference sites.
Three general exposure scenarios are considered for the generic test site: a rural residential
scenario where the individual lives on the site and produces food on the site, a
commercial/industrial scenario where an individual is on the site only during business hours,
and a suburban scenario where an individual uses the site as a residence. These three
scenarios and the exposure pathways used to describe them are discussed in Chapter 2. The
first two scenarios, but not the third, are used in the analysis of reference sites in Chapters 4,
5, and 6.
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Generic site risk factors were derived for 67 radionuclides for suburban, rural residential, and
commercial scenarios. Tables 3-1 through 3-3 present the generic suburban, rural residential,
and commercial/industrial site risk and dose factors calculated using RESRAD 5.19. Tables
3-4 through 3-6 present the risk and dose factors calculated using PRESTO-CPG, and Tables
3-7 through 3-9 present the risk and dose factors calculated using the modified RAGS/HHEM
equations.
The risk factors identified in these tables take into account radiological effects only.
Chemical toxicity, including the carcinogenic effects of chemicals and synergistic effects
resulting from combined chemical and radiological exposure, must also be evaluated, to the
extent that they are understood. Appendix F presents an evaluation of the combined effects of
radiation and hazardous chemical exposure.
3.1.1.1 Findings Regarding Differences in the Exposure Scenarios.
Figure 3-1 shows the percentage of radionuclides dominated by each exposure pathway
calculated using RESRAD (i.e., the percentage of radionuclides that have the highest risk
associated with that pathway), using data in Tables 3-1 through 3-3. Figures 3-2 and 3-3
show the same information for PRESTO and RAGS/HHEM, respectively. The following
comparative observations result:
All Models: Approximately half of the radionuclides have external exposure as
the dominant pathway in all three models.
• RESRAD: Risks associated with the majority of the remaining radionuclides
are divided between plant and water ingestion for suburban and rural residential
exposures. For commercial/industrial exposures the remaining radionuclides
are dominated by the water ingestion and inhalation pathways.
PRESTO: Risks associated with the majority of the remaining radionuclides
are divided between plant and water ingestion for suburban and rural residential
exposures. For commercial/industrial exposures the remaining radionuclides
are dominated by the water ingestion, soil ingestion, and inhalation pathways.
• RAGS/HHEM: Risks associated with the majority of the remaining
radionuclides are divided between water and plant ingestion for suburban and
rural residential exposures. For commercial/industrial exposures the remaining
radionuclides are dominated by the water ingestion pathway.
Review Draft - 9/26/94 3-3 Do Not Cite Or Quote
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TABLE 3-1. RESRAD (Ver. 5.19) RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Max
Nuclide Year
Ac-227 +D 0
Ag-108m+D 0
Ag-110m +D 0
Am-241 0
Am-243 +D 0
Bi-207 0
C-14 0
Cd-109 0
Ce-144+D 0
CI-36 0
Cm-243 0
Cm-244 0
Cm-248 0
Co-57 0
Co-60 0
Cs-134 0
Cs-135 0
Cs-137+D 0
Eu-152 0
Eu-154 0
Eu-155 0
Fe-55 0
Gd-153 0
H-3 1
1-129 4
K-40 0
Mn-54 0
Na-22 0
Nb-94 0
Ni-59 0
Ni-63 0
Np-237+D 17
Pa-231 364
Pb-210+D 0
Pm-147 0
Pu-238 0
Pu-239 0
Pu-240 0
Pu-241 68
Pu-242 0
Pu-244 +D 0
Ra-226 (+Rn) 1 1
Ra-226 (-Rn) 83
Ra-228 +D 2
Dose Rate
(mrem/yr)
per pCi/g
7
6
10
1
1
5
4
0.3
0.2
26
0.4
0.3
2
0.3
12
6
0.1
3
5
6
0.1
0.0005
0.1
0.05
41
2
3
8
7
0.002
0.01
96
30
5
0.0003
0.5
1
1
0.02
1
2
131
15
10
Lifetime Risk
per pCi/g
2.98E-05
1 .60E-04
2.99E-04
1.11E-06
8.06E-06
1 .48E-04
1.10E-04
9.38E-06
4.48E-06
1 .02E-03
4.87E-06
7.98E-07
3.88E-06
6.25E-06
2.69E-04
1.76E-04
2.50E-06
7.30E-05
1 .08E-04
1 .23E-04
1 .68E-06
1 .48E-08
1 .97E-06
2.98E-06
1 .52E-03
5.46E-05
8.79E-05
2.24E-04
1 .65E-04
1.12E-07
3.50E-07
1 .92E-04
3.47E-05
3.05E-05
2.43E-08
9.94E-07
9.58E-07
9.58E-07
3.25E-08
9.22E-07
9.70E-05
1.11E-03
2.38E-04
1.78E-04
Lifetime Risk
per mrem
1 .50E-07
8.90E-07
9.67E-07
6.32E-08
2.40E-07
9.69E-07
8.45E-07
1.14E-06
9.03E-07
1 .33E-06
4.18E-07
9.31 E-08
6.49E-08
7.55E-07
7.41 E-07
9.19E-07
1 .08E-06
7.75E-07
7.03E-07
7.22E-07
6.49E-07
1 .04E-06
5.95E-07
2.07E-06
1 .25E-06
1 .07E-06
9.41 E-07
8.90E-07
7.50E-07
1.75E-06
2.04E-06
6.62E-08
3.87E-08
1 .94E-07
2.96E-06
6.80E-08
5.83E-08
5.83E-08
6.29E-08
5.91 E-08
1 .94E-06
2.84E-07
5.17E-07
6.13E-07
Percent Lifetime Risk per Pathway
External
80
93
95
11
88
98
0
0
94
0
92
0
0
89
95
85
0
76
100
100
98
0
99
0
0
30
97
94
100
0
0
4
42
0
1
0
0
0
11
0
99
16
71
82
Inhalation
4
0
0
29
4
0
0
0
0
0
6
33
31
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
3
0
1
34
35
35
29
35
0
0
0
0
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
79
0
1
Plant
14
2
2
50
7
1
54
91
6
16
0
57
58
5
2
4
25
6
0
0
1
8
1
14
3
25
3
1
0
32
32
7
13
87
63
54
54
54
50
53
1
4
25
14
Meat
0
0
0
1
0
0
32
2
0
60
0
1
1
6
3
8
56
13
0
0
1
88
0
6
7
32
0
4
0
12
12
2
3
8
31
3
3
3
1
3
0
0
2
1
Milk
0
5
3
0
0
0
14
7
0
24
0
0
0
1
0
3
18
4
0
0
0
2
0
10
22
13
0
2
0
56
56
0
0
4
0
0
0
0
0
0
0
0
2
1
Soil
1
0
0
8
1
0
0
0
0
0
2
9
10
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
1
1
4
9
9
9
8
9
0
0
0
0
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
70
66
0
0
0
0
0
0
87
39
0
0
0
0
0
0
0
0
0
0
0
Fish
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-------
TABLE 3-1. RESRAD (Ver. 5.19) RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230 (+Rn)
Th-230 (-Rn)
Th-232 (+Rn)
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
0
0
780
0
0
1
0
0
694
1,000
66
691
1,000
0
0
0
49
49
49
49
49
49
49
49
49
49
49
49
0
Dose Rate
(mrem/yr)
per pCi/g
1
1
0.1
0.0001
5
1
7
2
24
5
16
40
20
16
16
0.1
10
2
2
2
2
2
2
2
4
4
138
22
5
Lifetime Risk
per pCi/g
2.46E-05
3.62E-05
7.32E-07
7.84E-09
8.06E-05
5.51 E-05
1 .68E-04
2.40E-05
2.11E-04
7.50E-05
2.95E-04
4.92E-04
3.48E-04
2.97E-04
2.93E-04
1 .90E-06
8.35E-05
1 .89E-05
1 .85E-05
2.41 E-05
1.75E-05
2.84E-05
3.04E-05
3.04E-05
4.81 E-05
4.81 E-05
1.17E-03
3.02E-04
1 .60E-04
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Lifetime Risk
per mrem
1 .09E-06
8.25E-07
1 .84E-07
2.57E-06
5.64E-07
2.23E-06
7.91 E-07
3.58E-07
2.89E-07
5.00E-07
6.09E-07
4.13E-07
5.85E-07
6.09E-07
6.14E-07
1 .06E-06
2.93E-07
2.77E-07
2.83E-07
3.38E-07
2.79E-07
4.42E-07
4.27E-07
4.27E-07
3.61 E-07
3.61 E-07
2.83E-07
4.59E-07
1.14E-06
Percent Lifetime Risk per Pathway
External
79
100
0
0
0
0
98
88
19
70
85
57
83
85
86
1
76
0
0
17
0
3
3
3
2
2
15
59
37
7.12E-07
6.02E-07
#N/A
4.70E-07
6.12E-07
3.87E-08
2.96E-06
Inhalation
0
0
6
1
0
0
1
6
0
0
1
0
1
1
1
0
1
1
1
1
1
0
0
0
1
1
0
0
0
Radon
0
0
0
0
0
0
0
0
72
0
1
32
0
1
0
0
0
0
0
0
0
0
0
0
0
0
74
0
0
Plant
18
0
17
63
60
36
1
6
7
25
11
9
14
11
11
73
2
5
5
4
5
5
5
5
5
5
6
22
9
Meat
3
0
9
31
31
0
0
0
1
2
1
1
1
1
1
9
0
1
1
0
1
1
1
1
1
1
0
2
48
Milk
0
0
0
0
9
4
0
0
1
2
1
1
1
1
1
17
0
2
2
2
2
2
2
2
2
2
0
2
6
Soil
0
0
1
4
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Water
0
0
66
0
0
59
0
0
0
0
0
0
0
0
0
0
21
91
91
76
91
89
89
89
89
89
4
14
0
Fish
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
* Modeling — RESRAD Version 5.19 (August 1994)
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values.
— 30-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
-------
TABLE 3-2. RESRAD (Ver. 5.19) RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING COMMERCIAL/INDUSTRIAL EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
0
0
0
0
0
0
0
0
0
6
0
0
0
0
0
0
1,000
0
0
0
0
0
0
1
4
0
0
0
0
488
488
17
377
0
0
0
0
0
61
0
0
0
0
3
Dose Rate
(mrem/yr)
per pCi/g
1
2
4
0.1
0.3
2
0.1
0.002
0.1
0.1
0.1
0.04
0.3
0.1
4
2
0.001
1
2
2
0.03
0.000002
0.04
0.02
13
0.2
1
3
3
0.0001
0.00001
44
10
0.02
0.00001
0.1
0.1
0.1
0.003
0.1
1
47
3
3
Lifetime Risk
per pCi/g
7.86E-06
4.60E-05
8.84E-05
1.51E-07
2.30E-06
4.51 E-05
8.70E-09
5.84E-09
1.31E-06
3.40E-06
1 .50E-06
9.34E-08
4.31 E-07
1.72E-06
7.91 E-05
4.65E-05
3.43E-08
1.72E-05
3.35E-05
3.81 E-05
5.12E-07
3.05E-11
6.05E-07
7.87E-07
4.20E-04
5.12E-06
2.65E-05
6.51 E-05
5.12E-05
3.28E-09
3.52E-10
7.19E-05
1 .07E-05
7.77E-08
2.27E-10
1.20E-07
1.15E-07
1.16E-07
4.45E-09
1.12E-07
2.99E-05
3.27E-04
5.58E-05
4.73E-05
Lifetime Risk
per mrem
1.76E-07
7.17E-07
7.92E-07
5.65E-08
2.66E-07
8.01 E-07
4.81 E-09
8.49E-08
7.19E-07
1.11E-06
3.59E-07
7.43E-08
4.91 E-08
5.90E-07
6.04E-07
7.44E-07
9.04E-07
5.94E-07
5.85E-07
6.01 E-07
5.34E-07
4.50E-07
4.91 E-07
1.73E-06
1 .04E-06
7.53E-07
7.77E-07
7.30E-07
6.24E-07
1 .44E-06
1 .69E-06
5.49E-08
3.66E-08
1 .65E-07
8.16E-07
5.61 E-08
4.89E-08
4.89E-08
5.55E-08
5.01 E-08
1 .97E-06
2.34E-07
6.23E-07
6.15E-07
Percent Lifetime Risk per
External
95
100
100
26
95
100
0
88
100
0
93
0
0
100
100
100
0
100
100
100
100
0
100
0
0
100
100
100
100
0
0
3
41
2
23
0
0
0
25
0
100
17
100
98
Inhalation
5
0
0
67
4
0
99
2
0
0
6
89
89
0
0
0
0
0
0
0
0
11
0
2
0
0
0
0
0
0
0
0
3
24
18
90
90
90
66
90
0
0
0
1
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
83
0
1
Pathway
Soil
0
0
0
8
1
0
1
11
0
0
1
11
11
0
0
0
1
0
0
0
0
89
0
0
0
0
0
0
0
0
0
0
0
75
59
10
10
10
8
10
0
0
0
0
Water
0
0
0
0
0
0
0
0
0
100
0
0
0
0
0
0
99
0
0
0
0
0
0
98
100
0
0
0
0
100
100
97
56
0
0
0
0
0
0
0
0
0
0
0
-------
TABLE 3-2. RESRAD (Ver. 5.19) RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING COMMERCIAL/INDUSTRIAL EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230 (+Rn)
Th-230 (-Rn)
Th-232 (+Rn)
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
0
0
780
0
49
1
0
0
683
1,000
66
681
1,000
0
0
0
49
49
49
49
49
49
49
49
49
49
49
49
0
Dose Rate
(mrem/yr)
per pCi/g
0.3
1
0.05
0.000005
0.2
0.2
3
1
8
1
4
13
5
5
4
0.0004
4
1
1
1
1
1
1
1
2
2
48
5
1
Lifetime Risk
per pCi/g
6.05E-06
1.12E-05
2.17E-07
6.19E-11
2.29E-06
1 .36E-05
5.17E-05
6.96E-06
5.93E-05
1 .64E-05
7.93E-05
1 .36E-04
9.10E-05
7.98E-05
7.88E-05
7.60E-09
2.71E-05
7.21 E-06
7.09E-06
8.93E-06
6.71 E-06
1 .08E-05
1.16E-05
1.16E-05
1 .83E-05
1 .83E-05
3.39E-04
7.38E-05
1 .86E-05
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Lifetime Risk
per mrem
7.71 E-07
6.85E-07
1.52E-07
4.35E-07
4.70E-07
1 .86E-06
6.61 E-07
3.28E-07
2.41 E-07
5.95E-07
5.89E-07
3.61 E-07
5.95E-07
5.89E-07
5.95E-07
5.88E-07
2.19E-07
2.31 E-07
2.36E-07
2.80E-07
2.32E-07
3.68E-07
3.56E-07
3.56E-07
3.01 E-07
3.01 E-07
2.37E-07
4.81 E-07
8.65E-07
Percent Lifetime Risk per
External
100
100
0
4
0
0
99
94
21
99
98
64
99
98
99
98
72
0
0
14
0
3
3
3
2
2
16
75
100
5.28E-07
4.86E-07
#N/A
3.46E-07
4.29E-07
4.81 E-09
1 .97E-06
Inhalation
0
0
7
26
0
0
1
6
0
1
1
0
1
1
1
0
1
1
1
0
1
0
0
0
0
0
0
0
0
Radon
0
0
0
0
0
0
0
0
79
0
1
35
0
1
0
0
0
0
0
0
0
0
0
0
0
0
78
0
0
Pathway
Soil
0
0
0
70
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
0
Water
0
0
93
0
100
100
0
0
0
0
0
0
0
0
0
0
27
99
99
85
99
97
97
97
98
98
5
24
0
* Modeling — RESRAD Version 5.19 (August 1994)
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values.
— 25-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
-------
TABLE 3-3. RESRAD (Ver. 5.19) RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING SUBURBAN EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
4
0
0
0
0
0
0
17
370
0
0
0
0
0
70
0
0
0
64
3
Dose Rate
(mrem/yr)
per pCi/g
3
6
10
0.2
1
5
1
0.1
0.2
2
0.3
0.1
1
0.3
12
6
0.01
3
5
6
0.1
0.00002
0.1
0.04
28
1
3
8
7
0.0003
0.001
90
21
2
0.0001
0.2
0.2
0.2
0.01
0.2
1
128
10
8
Lifetime Risk
per pCi/g
2.60E-05
1 .50E-04
2.87E-04
4.43E-07
7.38E-06
1 .46E-04
2.24E-05
3.47E-06
4.33E-06
6.58E-05
4.59E-06
2.60E-07
1 .30E-06
5.67E-06
2.57E-04
1 .53E-04
2.56E-07
5.73E-05
1 .08E-04
1 .23E-04
1 .66E-06
7.14E-10
1 .96E-06
2.26E-06
1 .03E-03
2.19E-05
8.64E-05
2.11E-04
1 .65E-04
1 .45E-08
4.56E-08
1 .80E-04
3.04E-05
1.11E-05
7.37E-09
3.08E-07
2.96E-07
2.96E-07
1 .30E-08
2.84E-07
9.63E-05
1 .08E-03
1 .96E-04
1 .60E-04
Lifetime Risk
per mrem
3.28E-07
8.64E-07
9.53E-07
7.33E-08
3.35E-07
9.64E-07
8.02E-07
1.10E-06
8.80E-07
1 .33E-06
5.53E-07
9.51 E-08
6.87E-08
7.16E-07
7.28E-07
8.96E-07
1 .08E-06
7.20E-07
7.02E-07
7.22E-07
6.43E-07
9.54E-07
5.91 E-07
2.07E-06
1 .25E-06
9.55E-07
9.36E-07
8.77E-07
7.50E-07
1.73E-06
2.04E-06
6.64E-08
4.80E-08
1 .94E-07
2.93E-06
6.82E-08
5.81 E-08
5.80E-08
7.31 E-08
5.84E-08
2.44E-06
2.82E-07
6.29E-07
6.89E-07
External
92
99
99
28
96
99
0
0
97
0
98
0
0
98
99
98
0
97
100
100
100
0
100
0
0
75
99
100
100
0
0
4
47
0
2
0
0
0
28
0
100
17
88
93
Inhalation
0
0
0
1
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
Percent Lifetime
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
82
0
1
Risk per Pathway
Plant
7
1
1
51
3
1
100
99
2
100
0
70
70
2
1
2
99
3
0
0
0
71
0
7
2
25
1
0
0
99
99
3
6
96
84
70
70
70
50
70
0
1
12
6
Soil
1
0
0
21
1
0
0
0
0
0
2
29
29
0
0
0
1
0
0
0
0
29
0
0
0
0
0
0
0
1
1
0
1
4
14
29
29
29
21
29
0
0
0
0
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
92
98
0
0
0
0
0
0
93
46
0
0
0
0
0
0
0
0
0
0
0
-------
TABLE 3-3. RESRAD (Ver. 5.19) RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING SUBURBAN EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230 (+Rn)
Th-230 (-Rn)
Th-232 (+Rn)
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
0
0
781
0
0
1
0
0
688
1,000
67
683
1,000
0
0
0
49
49
49
49
49
49
49
49
49
49
49
49
0
Dose Rate
(mrem/yr)
per pCi/g
1
1
0.1
0.00003
1
1
7
1
23
3
13
35
15
13
13
0.02
9
2
2
2
2
2
2
2
4
4
132
15
2
Lifetime Risk
per pCi/g
2.13E-05
3.61 E-05
5.44E-07
2.34E-09
1 .95E-05
4.08E-05
1 .66E-04
2.18E-05
1 .99E-04
6.05E-05
2.68E-04
4.59E-04
3.12E-04
2.68E-04
2.65E-04
5.84E-07
8.13E-05
1.77E-05
1.74E-05
2.29E-05
1 .64E-05
2.67E-05
2.87E-05
2.87E-05
4.52E-05
4.52E-05
1.12E-03
2.50E-04
6.56E-05
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Lifetime Risk
per mrem
9.85E-07
8.23E-07
1 .94E-07
2.83E-06
5.64E-07
2.23E-06
7.97E-07
5.54E-07
2.90E-07
6.18E-07
6.96E-07
4.33E-07
6.85E-07
6.93E-07
7.01 E-07
1 .04E-06
3.01 E-07
2.78E-07
2.85E-07
3.42E-07
2.80E-07
4.46E-07
4.31 E-07
4.31 E-07
3.64E-07
3.64E-07
2.84E-07
5.42E-07
1 .05E-06
Percent Lifetime Risk per Pathway
External
92
100
0
0
0
0
100
96
20
87
94
62
93
94
95
4
78
0
0
18
0
3
3
3
2
2
16
72
91
7.33E-07
6.64E-07
#N/A
4.93E-07
6.28E-07
4.80E-08
2.93E-06
Inhalation
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Radon
0
0
0
0
0
0
0
0
77
0
1
34
0
1
0
0
0
0
0
0
0
0
0
0
0
0
78
0
0
Plant
8
0
10
85
100
20
0
2
3
13
5
4
7
5
5
96
1
3
3
2
3
2
2
2
3
3
2
11
8
Soil
0
0
1
14
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Water
0
0
89
0
0
80
0
0
0
0
0
0
0
0
0
0
21
97
97
80
97
94
94
94
95
95
4
17
0
* Modeling — RESRAD Version 5.19 (August 1994)
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values.
— 30-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
-------
TABLE 3-4. PRESTO-CPG RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
1
1
1
1
1
1
839
1
1
1
1
1
806
1
1
1
262
1
1
1
1
1
1
2
814
112
1
1
1
1
1
839
806
1
1
1
44
1
1
428
1
1
1
Dose Rate
(mrem/yr)
per pCi/g
6
4
3
1
1
3
1
0.2
0.05
35
1
0.3
2
0.1
7
3
0.1
2
3
4
0.05
0.0001
0.03
0.0001
29
2
1
5
5
0.003
0.01
101
14
5
0.0002
1
1
1
0.01
1
1
NC
9
6
Lifetime Risk
per pCi/g
3.04E-05
1 .66E-04
1 .08E-04
1 .35E-06
8.25E-06
1 .43E-04
2.90E-05
5.57E-06
1 .84E-06
1 .39E-03
5.00E-06
9.81 E-07
5.02E-06
2.44E-06
2.34E-04
1 .32E-04
2.88E-06
7.27E-05
1 .OOE-04
1.10E-04
1 .42E-06
3.34E-09
6.77E-07
7.91 E-09
1 .08E-03
6.42E-05
3.91 E-05
1.74E-04
1 .60E-04
1.41 E-07
4.28E-07
1.91E-04
4.97E-06
3.04E-05
1.72E-08
1.21E-06
1 .20E-06
1 .20E-06
9.85E-09
1.13E-06
9.73E-05
NC
2.28E-04
1.12E-04
Lifetime Risk
per mrem
1.81 E-07
8.33E-07
8.77E-07
6.44E-08
2.60E-07
9.15E-07
8.46E-07
1 .OOE-06
8.21 E-07
1 .32E-06
7.48E-07
9.37E-08
6.67E-08
6.67E-07
6.97E-07
9.30E-07
1 .08E-06
6.90E-07
6.67E-07
6.79E-07
6.06E-07
1 .03E-06
5.58E-07
2.06E-06
1 .24E-06
9.42E-07
9.05E-07
8.85E-07
7.02E-07
1.75E-06
1 .96E-06
6.35E-08
2.02E-08
1 .90E-07
2.55E-06
6.67E-08
5.93E-08
5.93E-08
4.39E-06
5.83E-08
2.00E-06
NC
6.74E-07
6.21 E-07
Percent Lifetime
External
79
91
93
9
85
98
0
0
92
0
86
0
0
86
94
84
0
73
100
100
98
0
99
0
0
25
97
92
100
0
0
1
14
0
1
0
0
0
0
0
99
NC
79
68
Inhalation
4
0
0
24
4
0
0
0
0
0
6
26
24
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
0
1
29
28
28
15
28
0
NC
0
0
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
NC
0
0
Plant
14
2
2
41
7
1
0
86
6
12
10
46
48
5
2
4
22
6
0
0
1
30
1
38
10
20
3
1
0
25
26
16
46
85
70
44
44
44
53
44
1
NC
17
26
Risk per Pathway
Meat
0
1
0
0
0
0
0
3
0
60
0
0
0
8
3
9
56
15
0
0
0
51
0
0
13
36
0
4
0
11
11
3
20
6
12
0
0
0
0
0
0
NC
1
2
Milk
0
7
5
0
0
0
0
11
0
29
0
0
0
1
1
4
22
6
0
0
0
1
0
0
27
19
0
3
0
64
63
0
0
3
0
0
0
0
0
0
0
NC
2
3
Soil
3
0
0
25
4
0
0
0
2
0
6
28
28
0
0
0
0
0
0
0
0
18
0
0
0
0
0
0
0
0
0
0
3
5
17
27
27
27
31
26
0
NC
0
0
Water Fish
0 0
0 0
0 0
0 0
0 0
0 0
3 97
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 1
0 0
0 0
0 0
0 0
0 0
0 0
62 0
49 1
0 0
0 0
0 0
0 0
0 0
0 0
79 1
10 0
0 0
0 0
0 0
0 0
0 0
0 0
0 1
0 0
NC NC
0 0
0 0
-------
TABLE 3-4. PRESTO-CPG RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
1
1
187
1
1
2
1
1
368
806
1
1
902
902
902
902
902
1
Dose Rate
(mrem/yr)
per pCi/g
0.3
1
0.1
0.0001
5
0.5
3
2
0.2
1
NC
NC
NC
NC
0.1
0.5
2
3
2
2
2
NC
NC
NC
NC
NC
NC
2
Lifetime Risk
per pCi/g
1.27E-05
2.71E-05
3.36E-07
7.13E-09
9.11E-05
3.30E-05
1.12E-04
2.35E-05
4.58E-07
4.69E-07
NC
NC
NC
NC
1 .85E-06
1.70E-06
2.14E-05
2.14E-05
2.45E-05
2.02E-05
3.26E-05
NC
NC
NC
NC
NC
NC
7.19E-05
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Lifetime Risk
per mrem
9.65E-07
7.50E-07
1 .33E-07
2.00E-06
5.67E-07
2.21 E-06
7.19E-07
3.65E-07
7.78E-08
1 .64E-08
NC
NC
NC
NC
1 .OOE-06
1 .08E-07
3.00E-07
2.86E-07
3.33E-07
2.83E-07
4.50E-07
NC
NC
NC
NC
NC
NC
1.10E-06
Percent Lifetime
External
79
99
0
0
0
0
98
85
0
0
NC
NC
NC
NC
1
0
0
0
3
0
1
NC
NC
NC
NC
NC
NC
29
7.95E-07
6.90E-07
6.67E-08
4.59E-07
7.65E-07
1 .64E-08
4.39E-06
Inhalation
0
0
23
1
0
0
1
6
57
62
NC
NC
NC
NC
0
51
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Radon
0
0
0
0
0
0
0
0
0
0
NC
NC
NC
NC
0
0
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Plant
18
0
54
70
52
88
1
6
26
23
NC
NC
NC
NC
65
36
16
16
15
16
16
NC
NC
NC
NC
NC
NC
7
Risk per Pathway
Meat
3
0
10
12
35
1
0
0
0
0
NC
NC
NC
NC
11
1
1
1
1
1
1
NC
NC
NC
NC
NC
NC
56
Milk
0
0
0
0
13
11
0
0
0
0
NC
NC
NC
NC
23
3
3
3
3
3
3
NC
NC
NC
NC
NC
NC
8
Soil
0
0
13
17
0
0
0
3
16
14
NC
NC
NC
NC
0
9
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Water
0
0
0
0
0
0
0
0
0
0
NC
NC
NC
NC
0
0
79
79
77
79
80
NC
NC
NC
NC
NC
NC
0
Fish
0
0
0
0
0
0
0
0
0
1
NC
NC
NC
NC
0
0
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
* Modeling — PRESTO-CPG, SC&A Modifications, August, 1994
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values
— 30-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
NC Not Calculated
-------
Table 3-5. PRESTO-CPG RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING COMMERCIAL/INDUSTRIAL EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
1
1
1
1
1
1
491
1
1
469
1
1
1
1
1
1
1
1
1
1
1
1
1
4
466
117
1
1
1
1,000
1
491
743
1
1
1
1
1
1
1
1
NC
1
1
Dose Rate
(mrem/yr)
per pCi/g
1
2
1
0.1
0.3
1
0.02
0.001
0.02
0.1
0.1
0.1
0.5
0.03
3
1
0.0001
1
1
1
0.02
0.00001
0.01
0.00003
6
0.2
0.4
2
2
0.00002
0.00001
30
1
0.1
0.00001
0.1
0.1
0.1
0.002
0.1
0.4
NC
2
1
Lifetime
Risk
per pCi/g
7.94E-06
4.50E-05
3.10E-05
2.22E-07
2.39E-06
4.40E-05
3.20E-07
5.36E-09
5.28E-07
1 .90E-06
1 .47E-06
1 .49E-07
7.60E-07
6.60E-07
6.90E-05
3.40E-05
2.42E-09
1 .60E-05
3.10E-05
3.50E-05
4.31 E-07
1.53E-10
2.10E-07
1 .50E-09
2.00E-04
4.96E-06
1 .20E-05
5.10E-05
4.90E-05
8.01E-10
3.36E-10
4.94E-05
3.84E-07
4.09E-07
7.92E-10
1 .90E-07
1 .90E-07
1 .90E-07
1 .25E-09
1.76E-07
3.02E-05
NC
5.52E-05
2.31 E-05
Lifetime
Risk
per mrem
1.81 E-07
1 .OOE-06
1.11E-06
5.39E-08
2.93E-07
1.13E-06
7.11 E-07
1 .80E-07
1 .03E-06
1 .09E-06
3.62E-07
7.63E-08
5.39E-08
8.46E-07
8.85E-07
1.13E-06
8.99E-07
8.21 E-07
8.61 E-07
8.97E-07
7.55E-07
8.02E-07
7.15E-07
1 .67E-06
1 .04E-06
1 .09E-06
1.14E-06
1 .06E-06
8.60E-07
1 .43E-06
1 .47E-06
5.49E-08
1 .06E-08
1.61 E-07
1 .83E-06
5.60E-08
4.99E-08
4.98E-08
2.17E-08
4.89E-08
2.40E-06
NC
8.69E-07
7.91 E-07
Percent Lifetime Risk
External
92
100
100
17
92
100
0
52
98
0
89
0
0
100
100
100
0
100
100
100
100
0
100
0
0
99
100
100
100
0
0
1
22
0
5
0
0
0
0
0
99
NC
100
100
Inhalation
5
0
0
45
4
0
0
1
0
0
6
55
53
0
0
0
1
0
0
0
0
2
0
0
0
0
0
0
0
0
2
0
10
4
4
58
58
58
38
57
0
NC
0
0
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
NC
0
0
Per Pathway
Soil
3
0
0
38
4
0
0
47
2
0
5
45
47
0
0
0
99
0
0
0
0
98
0
0
0
0
0
0
0
2
98
0
3
95
91
42
42
42
62
43
0
NC
0
0
Water
0
0
0
0
0
0
100
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
100
100
1
0
0
0
97
0
99
65
0
0
0
0
0
0
0
0
NC
0
0
-------
Table 3-5. PRESTO-CPG RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING COMMERCIAL/INDUSTRIAL EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
1
1
1
1
1
460
1
1
1
1
NC
NC
NC
NC
1
1
554
554
554
554
554
NC
NC
NC
NC
NC
NC
1
Dose Rate
(mrem/yr)
per pCi/g
0.1
0.3
0.01
0.00001
0.002
0.1
1
1
0.1
0.3
NC
NC
NC
NC
0.0003
0.1
1
1
1
1
1
NC
NC
NC
NC
NC
NC
0.2
Lifetime
Risk
per pCi/g
3.11E-06
8.40E-06
3.60E-08
3.19E-10
2.43E-08
3.60E-06
3.55E-05
6.83E-06
1.01E-07
1 .08E-07
NC
NC
NC
NC
6.90E-09
3.17E-07
5.41 E-06
5.31 E-06
6.06E-06
5.01 E-06
7.97E-06
NC
NC
NC
NC
NC
NC
6.50E-06
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Lifetime
Risk
per mrem
1.13E-06
9.66E-07
9.84E-08
1.27E-06
4.30E-07
1 .85E-06
9.55E-07
3.59E-07
6.39E-08
1 .36E-08
NC
NC
NC
NC
8.41 E-07
9.42E-08
2.50E-07
2.35E-07
2.74E-07
2.31 E-07
3.67E-07
NC
NC
NC
NC
NC
NC
1.27E-06
Percent Lifetime Risk Per Pathway
External
100
100
0
1
0
0
99
91
0
0
NC
NC
NC
NC
87
0
0
0
4
0
1
NC
NC
NC
NC
NC
NC
100
7.00E-07
8.02E-07
#N/A
3.91 E-07
5.53E-07
1 .06E-08
2.40E-06
Inhalation
0
0
69
5
1
0
1
6
82
85
NC
NC
NC
NC
0
88
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Radon
0
0
0
0
0
0
0
0
0
0
NC
NC
NC
NC
0
0
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Soil
0
0
31
94
99
0
0
3
18
15
NC
NC
NC
NC
13
12
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Water
0
0
0
0
0
100
0
0
0
0
NC
NC
NC
NC
0
0
100
100
96
100
99
NC
NC
NC
NC
NC
NC
0
* Modeling — PRESTO-CPG, SC&A Modifications, August, 1994
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values
— 25-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
NC Not Calculated
-------
TABLE 3-6. PRESTO-CPG RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING SUBURBAN EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
1
1
1
1
1
1
839
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
814
113
1
1
1
806
1
839
806
1
1
1
1
1
1
1
1
1
1
Dose Rate
(mrem/yr)
per pCi/g
3
4
3
0.3
1
3
0.04
0.1
0.05
2
0.3
0.2
1
0.1
7
3
0.01
2
3
4
0.05
0.00003
0.03
0.0001
16
1
1
4
5
0.0003
0.001
90
5
2
0.0001
0.3
0.3
0.3
0.005
0.3
1
NC
7
4
Lifetime Risk
per pCi/g
2.67E-05
1.51E-04
1.01E-04
6.83E-07
7.58E-06
1.41E-04
9.80E-07
1 .92E-06
1.78E-06
6.50E-05
5.00E-06
4.52E-07
2.35E-06
2.15E-06
2.22E-04
1.12E-04
2.60E-07
5.48E-05
1 .OOE-04
1.10E-04
1.41E-06
9.90E-10
6.73E-07
6.20E-09
5.95E-04
2.14E-05
3.84E-05
1 .60E-04
1 .60E-04
1 .46E-08
4.54E-08
1.70E-04
2.29E-06
1.16E-05
7.73E-09
5.33E-07
5.33E-07
5.33E-07
5.11E-09
5.03E-07
9.66E-05
NC
1 .97E-04
8.85E-05
Lifetime Risk
per mrem
1.81E-07
8.33E-07
8.77E-07
6.44E-08
2.60E-07
9.15E-07
8.46E-07
1 .OOE-06
8.21 E-07
1 .32E-06
7.48E-07
9.37E-08
6.67E-08
6.67E-07
6.97E-07
9.30E-07
1 .08E-06
6.90E-07
6.67E-07
6.79E-07
6.06E-07
1 .03E-06
5.58E-07
2.06E-06
1 .24E-06
9.42E-07
9.05E-07
8.85E-07
7.02E-07
1.75E-06
1 .96E-06
6.35E-08
2.02E-08
1 .90E-07
2.55E-06
6.67E-08
5.93E-08
5.93E-08
4.39E-06
5.83E-08
2.00E-06
NC
6.74E-07
6.21 E-07
External
90
99
99
18
92
99
0
0
96
0
86
0
0
98
99
98
0
97
100
100
99
0
100
0
0
75
99
100
100
0
0
1
31
0
2
0
0
0
0
0
99
NC
92
86
Inhalation
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
NC
0
0
°ercent Lifetime
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
NC
0
0
Risk per Pathway
Plant
6
1
1
32
3
1
0
99
2
100
4
40
40
2
1
2
96
3
0
0
0
39
0
21
11
25
1
0
0
96
97
11
41
86
61
39
39
39
39
40
0
NC
8
14
Soil
4
0
0
50
5
0
0
1
2
0
6
60
60
0
0
0
4
0
0
0
0
61
0
0
0
0
0
0
0
3
3
0
6
14
38
60
60
60
61
60
0
NC
0
1
Water
0
0
0
0
0
0
100
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
79
89
1
0
0
0
1
0
88
22
0
0
0
0
0
0
0
0
NC
0
0
-------
TABLE 3-6. PRESTO-CPG RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING SUBURBAN EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
1
1
1
1
1
2
1
1
1
1
1
104
902
902
902
902
902
1
Dose Rate
(mrem/yr)
per pCi/g
0.3
1
0.02
0.00004
1
0.2
3
1
0.04
0.2
NC
NC
NC
NC
0.02
0.1
2
2
2
2
2
NC
NC
NC
NC
NC
NC
1
Lifetime Risk
per pCi/g
1.10E-05
2.71E-05
1.18E-07
3.21 E-09
1.91E-05
1.21E-05
1.11E-04
2.14E-05
1.27E-07
1 .09E-07
NC
NC
NC
NC
4.93E-07
4.18E-07
1.91E-05
1.91E-05
2.21 E-05
1 .80E-05
2.93E-05
NC
NC
NC
NC
NC
NC
2.30E-05
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Jfetime Risk
per mrem
9.65E-07
7.50E-07
1 .33E-07
2.00E-06
5.67E-07
2.21 E-06
7.19E-07
3.65E-07
7.78E-08
1 .64E-08
NC
NC
NC
NC
1 .OOE-06
1 .08E-07
3.00E-07
2.86E-07
3.33E-07
2.83E-07
4.50E-07
NC
NC
NC
NC
NC
NC
1.10E-06
Percent Lifetime Risk per Pathway
External
91
100
0
0
0
0
99
94
1
1
NC
NC
NC
NC
4
0
0
0
4
0
1
NC
NC
NC
NC
NC
NC
91
7.95E-07
6.90E-07
6.67E-08
4.59E-07
7.65E-07
1 .64E-08
4.39E-06
Inhalation
0
0
1
0
0
0
0
0
2
2
NC
NC
NC
NC
0
1
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Radon
0
0
0
0
0
0
0
0
0
0
NC
NC
NC
NC
0
0
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Plant
8
0
61
62
99
99
0
2
39
39
NC
NC
NC
NC
95
29
11
11
10
11
11
NC
NC
NC
NC
NC
NC
9
Soil
0
0
38
37
1
0
0
4
59
59
NC
NC
NC
NC
1
13
0
0
0
0
0
NC
NC
NC
NC
NC
NC
0
Water
0
0
0
0
0
1
0
0
0
0
NC
NC
NC
NC
0
57
89
89
86
89
89
NC
NC
NC
NC
NC
NC
0
* Modeling — PRESTO-CPG, SC&A Modifications, August, 1994
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values
— 30-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
NC Not Calculated
-------
TABLE 3-7. RAGS/HHEM PART B RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dose Rate
(mrem/yr)
per pCi/g
11
4
7
1
1
4
4
0.3
0.1
27
0.6
0.4
3
0.2
9
5
0.1
2
4
4
0.1
0.001
0.1
0.2
62
2
2
6
5
0.003
0.007
63
21
8
0.0006
1
1
1
0.02
1
2
196
9
7
Lifetime Risk
per pCi/g
3.85E-05
1 .60E-04
2.94E-04
1 .66E-06
8.57E-06
1 .47E-04
9.19E-05
1 .02E-05
4.71 E-06
1 .06E-03
5.76E-06
1.13E-06
5.65E-06
6.40E-06
2.72E-04
1 .83E-04
2.77E-06
7.41 E-05
1 .07E-04
1.22E-04
1 .68E-06
3.09E-08
1 .97E-06
1 .30E-05
2.31 E-03
6.37E-05
8.77E-05
2.37E-04
1 .59E-04
1 .39E-07
4.26E-07
1 .33E-04
7.19E-06
4.35E-05
5.63E-08
2.22E-06
2.19E-06
2.19E-06
2.05E-08
2.08E-06
9.79E-05
1 .86E-03
2.25E-04
1 .46E-04
Lifetime Risk
per mrem
1.15E-07
1 .26E-06
1 .35E-06
6.27E-08
2.29E-07
1 .39E-06
8.42E-07
1.13E-06
1 .33E-06
1 .32E-06
3.17E-07
9.47E-08
6.81 E-08
1 .08E-06
1 .07E-06
1 .29E-06
1 .08E-06
1 .03E-06
1.01 E-06
1 .04E-06
9.35E-07
1 .06E-06
8.58E-07
2.05E-06
1 .24E-06
1.17E-06
1 .35E-06
1 .28E-06
1 .05E-06
1.76E-06
1 .99E-06
7.00E-08
1.13E-08
1 .93E-07
3.10E-06
6.76E-08
5.92E-08
5.92E-08
3.46E-08
5.91 E-08
1 .68E-06
3.16E-07
8.12E-07
6.99E-07
Percent of Lifetime Risk
External
63
92
94
7
82
98
0
0
87
0
78
0
0
86
94
84
0
74
100
100
96
0
97
0
0
25
97
90
100
0
0
9
10
0
0
0
0
0
0
0
98
9
78
59
Inhalation
3
0
0
20
4
0
0
0
0
0
5
23
22
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
0
0
16
15
15
8
15
0
0
0
0
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
88
0
13
Plant
11
2
2
33
7
1
22
82
5
15
1
40
41
5
2
4
23
6
0
0
1
4
1
10
1
21
3
1
0
26
26
8
31
61
27
24
24
24
3
24
1
2
17
22
Meat
0
0
0
1
0
0
43
2
0
59
0
0
0
7
3
9
53
14
0
0
1
65
0
19
9
31
0
4
0
10
10
4
24
6
18
1
1
1
0
1
0
0
1
2
Per Pathway
Milk
0
5
4
0
0
0
21
8
0
25
0
0
0
1
1
3
20
5
0
0
0
2
0
51
61
18
0
4
0
60
60
0
0
4
0
0
0
0
0
0
0
0
2
2
Soil
3
0
0
21
4
0
0
0
2
0
5
25
26
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0
0
2
4
7
15
15
15
16
15
0
0
0
0
Water
19
0
0
18
4
0
1
7
6
0
2
10
11
1
0
0
2
1
0
0
2
25
1
21
29
4
0
0
0
4
4
78
29
23
47
44
44
44
48
44
1
0
1
1
Fish
0
0
0
0
0
0
13
0
0
0
0
0
0
0
0
0
1
0
0
0
0
2
0
0
0
1
0
0
0
0
0
1
0
2
0
0
0
0
0
0
0
0
0
0
-------
TABLE 3-7. RAGS/HHEM PART B RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dose Rate
(mrem/yr)
per pCi/g
1
1
0.1
0.0002
6
1
5
2
0.2
1
6
6
13
13
0.1
7
0.2
1
2
1
1
2
2
3
3
209
22
4
Lifetime Risk
per pCi/g
2.80E-05
3.56E-05
7.36E-07
1.81E-08
1.01E-04
6.89E-05
1 .85E-04
2.41 E-05
5.03E-07
2.01 E-05
2.06E-04
1 .66E-04
3.52E-04
2.93E-04
3.72E-06
2.10E-05
1.27E-05
1.27E-05
2.06E-05
1 .20E-05
2.01 E-05
2.07E-05
2.07E-05
3.38E-05
3.38E-05
1 .94E-03
3.05E-04
1.76E-04
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Jfetime Risk
per mrem
1 .65E-06
1.17E-06
1.78E-07
2.73E-06
5.67E-07
2.22E-06
1 .24E-06
3.80E-07
8.69E-08
6.85E-07
1.12E-06
9.04E-07
9.07E-07
7.55E-07
1 .07E-06
9.33E-08
2.25E-06
2.82E-07
3.91 E-07
2.78E-07
4.53E-07
4.48E-07
4.48E-07
3.68E-07
3.68E-07
3.10E-07
4.70E-07
1.31E-06
Percent of Lifetime Risk Per Pathway
External
71
98
0
0
0
0
87
83
0
0
79
97
70
85
1
0
0
0
34
0
7
8
8
5
5
9
59
34
8.63E-07
8.81 E-07
4.48E-07
5.27E-07
6.79E-07
1.13E-08
3.10E-06
Inhalation
0
0
11
0
0
0
1
6
52
1
1
1
1
1
0
4
2
2
1
2
1
1
1
1
1
0
0
0
Radon
0
0
0
0
0
0
11
0
0
98
19
0
17
0
0
0
0
0
0
0
0
0
0
0
0
84
0
0
Plant
16
0
25
27
48
43
0
5
24
1
1
1
10
12
37
3
3
3
2
3
3
3
3
3
3
3
22
8
Meat
3
0
16
18
29
0
0
0
1
0
0
0
1
1
6
1
2
2
1
2
1
1
1
1
1
0
2
52
Milk
0
0
0
0
12
12
0
0
0
0
0
0
1
1
15
11
11
11
7
11
10
10
10
10
10
0
3
6
Soil
0
0
6
7
0
0
0
3
15
0
0
0
0
0
0
1
1
1
0
1
1
1
1
1
1
0
1
0
Water
10
1
42
47
11
44
0
2
8
0
0
0
1
1
10
80
82
82
54
82
76
76
76
78
78
2
13
0
Fish
0
0
0
0
0
0
0
0
0
0
0
0
0
0
32
0
0
0
0
0
0
0
0
0
0
0
0
0
* Modeling — RAGS/HHEM Part B Equations, SC&A Modifications, August, 1994
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values
— 30-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
-------
Table 3-8. RAGS/HHEM PART B RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING COMMERCIAL/INDUSTRIAL EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dose Rate
(mrem/yr)
per pCi/g
5
1
3
0.3
0.5
1
0.02
0.02
0.04
0.1
0.2
0.1
1
0.1
3
1
0.002
1
1
1
0.02
0.0002
0.03
0.03
13
0.2
1
2
2
0.00007
0.0002
39
6
1.0
0.0002
1
1
1
0.01
1.0
1.0
70
2
1
Lifetime
Risk
per pCi/g
1 .30E-05
4.60E-05
8.64E-05
5.25E-07
2.69E-06
4.54E-05
4.35E-07
4.43E-07
1 .48E-06
3.10E-06
1.77E-06
3.24E-07
1 .62E-06
1.75E-06
8.05E-05
4.85E-05
4.12E-08
1.74E-05
3.34E-05
3.82E-05
5.25E-07
4.98E-09
6.15E-07
1.61E-06
3.94E-04
6.68E-06
2.67E-05
6.73E-05
4.98E-05
3.19E-09
9.78E-09
6.55E-05
1 .65E-06
6.97E-06
1.81E-08
8.90E-07
8.80E-07
8.80E-07
8.35E-09
8.36E-07
3.08E-05
1 .69E-03
5.67E-05
3.40E-05
Lifetime
Risk
per mrem
1 .06E-07
1 .24E-06
1 .34E-06
6.26E-08
2.27E-07
1 .39E-06
8.42E-07
1 .05E-06
1 .33E-06
1 .32E-06
3.29E-07
9.44E-08
6.77E-08
1 .02E-06
1 .06E-06
1 .33E-06
1 .08E+06
1 .02E-06
1.01E+06
1 .04-06
9.36E-07
1 .05E-06
8.58E-07
2.05E-06
1 .24E-06
1 .23E-06
1 .35E-06
1 .30E-06
1 .05E-06
1.73E-06
1 .99E-06
6.78E-08
1.19E-08
1 .93E-07
3.10E-06
6.76E-08
5.92E-08
5.92E-08
3.52E-08
5.91 E-08
1 .45E-06
9.75E-07
1 .02E-06
1 .09E-06
External
58
100
100
7
82
99
0
1
86
0
80
0
0
98
99
99
0
98
100
100
96
0
97
0
0
75
100
99
100
0
0
6
14
0
0
0
0
0
0
0
97
3
97
79
Percent
Inhalation
3
0
0
20
4
0
0
0
0
0
5
27
25
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
0
0
13
13
13
6
13
0
0
0
0
Lifetime Risk
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
97
0
17
Per Pathway
Soil
2
0
0
16
3
0
0
1
1
0
4
21
22
0
0
0
6
0
0
0
0
3
0
0
0
0
0
0
0
1
3
0
1
6
4
9
9
9
9
9
0
NC
0
0
Water
34
0
0
34
7
1
100
97
11
100
4
22
22
2
1
1
86
1
0
0
3
91
2
100
100
25
0
1
0
92
92
94
75
86
87
66
66
66
70
66
2
0
2
3
-------
Table 3-8. RAGS/HHEM PART B RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING COMMERCIAL/INDUSTRIAL EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dose Rate
(mrem/yr)
per pCi/g
0.2
0.4
0.05
0.00009
0.5
0.3
2
1
0.1
0.4
2
2
3
3
0.008
4
0.1
1
1
1
1
1
1
2
2
73
6
1
Lifetime
Risk
per pCi/g
7.78E-06
1.12E-05
2.36E-07
5.82E-09
6.64E-06
1.81E-05
5.76E-05
7.46E-06
1.52E-07
6.05E-06
6.38E-05
5.20E-05
9.76E-05
7.99E-05
2.23E-07
1 .03E-05
6.32E-06
6.29E-06
8.94E-06
5.94E-06
9.75E-06
1 .05E-05
1 .05E-05
1 .65E-05
1 .65E-05
1.72E-03
8.11E-05
1 .87E-05
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Lifetime
Risk
per mrem
1 .56E-06
1.17E-06
1.78E-07
2.73E-06
5.67E-07
2.22E-06
1 .24E-06
3.82E-07
8.55E-08
6.70E-07
1.11E-06
9.08E-07
1.13E-06
9.22E-07
1 .07E-06
9.30E-08
2.46E-06
2.83E-07
3.68E-07
2.79E-07
4.48E-07
4.33E-07
4.33E-07
3.65E-07
3.65E-07
9.37E-07
5.35E-07
1 .49E-06
Percent Lifetime Risk Per Pathway
External
79
98
0
0
0
0
88
84
0
0
79
97
79
97
3
0
0
0
24
0
5
5
5
4
4
3
69
99
8.94E-07
9.91 E-07
4.33E-07
5.51 E-07
6.77E-07
1.19E-08
3.10E-06
Inhalation
0
0
11
0
0
0
1
6
55
2
1
1
1
1
0
3
1
1
1
1
1
1
1
1
1
0
0
0
Radon
0
0
0
0
0
0
10
0
0
97
18
0
18
0
0
0
0
0
0
0
0
0
0
0
0
95
0
0
Soil
1
0
11
13
1
0
1
7
29
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
2
0
Water
21
2
78
87
99
100
0
3
15
0
0
0
1
2
96
96
98
98
74
98
94
94
94
95
95
1
28
1
* Modeling
Assumptions:
RAGS/HHEM Part B Equations, SC&A Modifications, August, 1994
Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
EPA's new 30-yr slope factors
Updated base case Kd values
25-yr exposure duration
1,000-yr time horizon for dose/risk calculations
-------
TABLE 3-9. RAGS/HHEM PART B RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING SUBURBAN EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Ra-226 (-Rn)
Ra-228 +D
Max
Year
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dose Rate
(mrem/yr)
per pCi/g
7
4
7
0.5
1
3
0.3
0.1
0.1
2
0.4
0.2
1
0.2
8
4
0.01
2
4
4
0.1
0.0003
0.1
0.1
18
1
2
6
5
0.0004
0.001
56
11
4
0.0004
1
1
1
0.01
1
2
194
7
4
Lifetime Risk
per pCi/g
3.46E-05
1 .48E-04
2.78E-04
9.86E-07
7.90E-06
1 .45E-04
8.70E-06
4.12E-06
4.54E-06
7.00E-05
5.16E-06
5.85E-07
3.00E-06
5.67E-06
2.59E-04
1 .57E-04
3.20E-07
5.69E-05
1 .07E-04
1.22E-04
1 .66E-06
8.86E-09
1 .95E-06
3.22E-06
6.67E-04
2.41 E-05
8.62E-05
2.15E-04
1 .59E-04
1 .98E-08
6.05E-08
1 .20E-04
3.84E-06
2.23E-05
3.65E-08
1 .52E-06
1 .50E-06
1 .50E-06
1 .53E-08
1 .43E-06
9.72E-05
1 .83E-03
1 .95E-04
1.21E-04
Lifetime Risk
per mrem
1 .64E-07
1 .24E-06
1 .34E-06
6.62E-08
3.05E-07
1 .39E-06
8.42E-07
1.11E-06
1 .30E-06
1 .32E-06
4.43E-07
9.72E-08
7.16E-08
1 .03E-06
1 .06E-06
1 .32E-06
1 .08E-06
1 .02E-06
1.01E-06
1 .04E-06
9.27E-07
1 .05E-06
8.52E-07
2.05E-06
1 .24E-06
1.22E-06
1 .35E-06
1 .30E-06
1 .05E-06
1.75E-06
1 .99E-06
7.07E-08
1.21E-08
1 .93E-07
3.14E-06
6.76E-08
5.92E-08
5.92E-08
3.78E-08
5.90E-08
2.05E-06
3.15E-07
9.38E-07
9.06E-07
Percent of Lifetime
External
71
99
99
12
89
99
0
0
90
0
87
0
0
97
99
98
0
96
100
100
97
0
98
0
0
66
99
99
100
0
0
10
19
0
0
0
0
0
0
0
98
10
91
71
Inhalation
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Radon
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
89
0
16
Risk Per Pathway
Plant
5
1
1
22
3
1
92
82
2
93
1
31
31
2
1
2
78
3
0
0
0
6
0
16
1
22
1
0
0
73
73
3
23
48
17
14
14
14
4
14
0
1
8
11
Soil
3
0
0
35
4
0
0
0
2
0
6
48
48
0
0
0
3
0
0
0
0
9
0
0
0
0
0
0
0
2
2
0
4
7
10
21
21
21
21
21
0
0
0
0
Water
21
0
0
30
4
1
8
17
6
7
3
20
20
1
0
0
19
1
0
0
2
86
1
84
99
12
0
0
0
25
25
86
54
45
72
65
65
65
65
65
1
0
1
1
-------
TABLE 3-9. RAGS/HHEM PART B RISK FACTORS AND DOSE FACTORS FOR THE GENERIC SITE, ASSUMING SUBURBAN EXPOSURE*
Nuclide
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Max
Year
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Dose Rate
(mrem/yr)
per pCi/g
1
1
0.1
0.0001
2
1
5
1
0.05
0.3
5
5
10
10
0.03
6
0.1
1
2
1
1
1
1
3
3
201
14
1
Lifetime Risk
per pCi/g
2.44E-05
3.55E-05
4.28E-07
1.17E-08
3.07E-05
4.22E-05
1 .83E-04
2.19E-05
1 .65E-07
1 .98E-05
2.03E-04
1 .64E-04
3.23E-04
2.64E-04
9.47E-07
1.71E-05
1 .06E-05
1 .06E-05
1 .84E-05
1 .OOE-05
1.72E-05
1.77E-05
1.77E-05
2.87E-05
2.87E-05
1 .89E-03
2.48E-04
6.52E-05
Mean
Median
Mode
Geometric Mean
Std. Dev.
Min.
Max.
Jfetime Risk
per mrem
1 .54E-06
1.17E-06
1.97E-07
2.86E-06
5.67E-07
2.22E-06
1.27E-06
6.19E-07
1.10E-07
2.54E-06
1 .32E-06
1 .06E-06
1.13E-06
9.27E-07
1 .07E-06
9.25E-08
2.97E-06
2.86E-07
4.07E-07
2.81 E-07
4.65E-07
4.61 E-07
4.61 E-07
3.76E-07
3.76E-07
3.12E-07
5.80E-07
1 .46E-06
Percent of Lifetime
External
81
99
0
0
0
0
89
92
1
0
80
99
77
94
2
0
0
0
38
0
9
9
9
6
6
10
72
91
9.31 E-07
9.72E-07
4.61 E-07
5.69E-07
7.38E-07
1.21E-08
3.14E-06
Inhalation
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Radon
0
0
0
0
0
0
11
0
0
99
19
0
18
0
0
0
0
0
0
0
0
0
0
0
0
87
0
0
Risk Per Pathway
Plant
7
0
17
17
64
28
0
2
29
0
0
0
4
5
59
1
1
1
1
1
1
1
1
1
1
1
11
9
Soil
0
0
10
10
0
0
0
4
45
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
0
1
0
Water
11
1
72
73
36
72
0
2
24
0
0
0
1
1
38
98
98
98
61
98
89
89
89
91
91
2
16
0
* Modeling — RAGS/HHEM Part B Equations, SC&A Modifications, August, 1994
Assumptions: — Generic site characteristics (10,000 m2 area by 2 m deep contaminated zone; 2 m thick unsaturated zone)
— EPA's new 30-yr slope factors
— Updated base case Kd values
— 30-yr exposure duration
— 1,000-yr time horizon for dose/risk calculations
-------
ft
O
o
O
FT
O
£
FT
Figure 3-1. Radionuclide Distribution by Dominant Pathway
RESRAD Version 5.19
External 49%
External 47%
Radon 4%
Water 19%
Radon 4%
Water 19%
Plant 27%
Milk 3%
Meat 7%
Suburban
External 51%
Rural
Residential
Plant 21%
Inhalation 12%
Soil 5%
Radon 4%
Water 27%
Commercial/Industrial
-------
ft
O
o
o^
FT
Figure 3-2. Radionuclide Distribution by Dominant Pathway
PRESTO-CPG
External 44%
Water 16%
Plant 21%
Soil 18%
Suburban
Inhalation 18%
External 41%
Inhalation 5%
Water 15%
External 48%
RQFal26%
Residential
Soil 13%
Water 21%
Commercial/Industrial
Fish 2%
Milk 3%
Meat 8%
-------
ft
O
o
O
FT
O
Figure 3-3. Radionuclide Distribution by Dominant Pathway
RAGS/HHEM
External 44%
External 42%
Radon 4%
Plant 13%
Water 33% ^ "^ Soil 6%
Suburban
Inhalation 1%
Radon 4%
Inhalation 1%
Radon 4%
Water 26%
Milk 6%
Meat 8%
External 44%
Rural
Residential
Plant 13%
Soil 4%
Water 46%
Commercial/Industrial
-------
All three models demonstrate that the rural residential scenario is more conservative than the
suburban or commercial/industrial scenarios. For example, Tables 3-1 through 3-3 for
RESRAD calculations show that for Cs-137+D, the risk factor is: 7.3xlO"5 for the rural
residential scenario, 5.7xlO"5 for the suburban scenario, and 1.7xlO"5 for the
commercial/industrial scenario.
Radionuclides dominated by external exposure to radiation, such as Cs-137+D, have less
variation between scenarios than radionuclides dominated by ingestion and inhalation
pathways, such as Pu-239. The RESRAD results show that the risk factor for Pu-239 is
9.6xlO"7 for the rural residential scenario, 3.0xlO"7 for the suburban scenario, and 1.2xlO"7 for
the commercial/industrial scenario.
3.1.1.2 Findings Regarding Differences Between the Three Models.
Several important differences among the three models were described in Chapter 2. The
results of the generic test site calculations are compared in Table 3-10, which lists the risk
factors obtained with each of the three models and provides a brief explanation of the
differences.
The differences in the behaviors over time of the source terms of the three models are
significant. The soil concentration at the beginning of the simulation is the same for all three.
Thus, each model should give similar results for external exposure, inhalation, and soil, plant,
meat, and milk ingestion for situations in which the maximum exposure occurs at the
beginning of the simulation. Such is the case for 22 radionuclides.
Most of the differences in the results are caused by the differences in decay and ingrowth
calculations. PRESTO does not provide initial results for the beginning of the simulation, but
provides annual results starting at the end of the first year. The radionuclide decay in the first
year causes changes in the results for eleven radionuclides (Ag-llOm+D, Cd-109, Ce-144+D,
Co-57, Eu-155, Gd-153, H-3, Mn-54, Na-22, Ru-106+D, and Sb-125+D). RESRAD includes
ingrowth of principal radionuclides, and this affects the results for five radionuclides (Pa-231,
Pu-241, Th-230, Th-232, and U-232). In addition, PRESTO decays H-3 and U-232 before
they reach groundwater and calculates lower risk factors for these radionuclides, because of
differences in the release submodel.
Review Draft - 9/26/94 3-25 Do Not Cite Or Quote
-------
TABLE 3-10. COMPARISON OF MODEL RESULTS FOR THE GENERIC TEST SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ac-227 +D
Ag-108m +D
Ag-110m +D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
CI-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241
Pu-242
Pu-244 +D
Ra-226 (+Rn)
Risk Factor
RESRAD
2.98E-05
1 .60E-04
2.99E-04
1.11E-06
8.06E-06
1 .48E-04
1.10E-04
9.38E-06
4.48E-06
1 .02E-03
4.87E-06
7.98E-07
3.88E-06
6.25E-06
2.69E-04
1.76E-04
2.50E-06
7.30E-05
1 .08E-04
1 .23E-04
1 .68E-06
1 .48E-08
1 .97E-06
2.98E-06
1 .52E-03
5.46E-05
8.79E-05
2.24E-04
1 .65E-04
1.12E-07
3.50E-07
1 .92E-04
3.47E-05
3.05E-05
2.43E-08
9.94E-07
9.58E-07
9.58E-07
3.25E-08
9.22E-07
9.70E-05
1.11E-03
PRESTO
3.04E-05
1 .66E-04
1 .08E-04
1 .35E-06
8.25E-06
1 .43E-04
2.90E-05
5.57E-06
1 .84E-06
1 .39E-03
5.00E-06
9.81 E-07
5.02E-06
2.44E-06
2.34E-04
1 .32E-04
2.88E-06
7.27E-05
1 .OOE-04
1.10E-04
1 .42E-06
3.34E-09
6.77E-07
7.91 E-09
1 .08E-03
6.42E-05
3.91 E-05
1.74E-04
1 .60E-04
1.41 E-07
4.28E-07
1.91E-04
4.97E-06
3.04E-05
1.72E-08
1.21E-06
1 .20E-06
1 .20E-06
9.85E-09
1.13E-06
9.73E-05
NC
RAGS/HHEM
3.85E-05
1 .60E-04
2.94E-04
1 .66E-06
8.57E-06
1 .47E-04
9.19E-05
1 .02E-05
4.71 E-06
1 .06E-03
5.76E-06
1.13E-06
5.65E-06
6.40E-06
2.72E-04
1 .83E-04
2.77E-06
7.41 E-05
1 .07E-04
1.22E-04
1 .68E-06
3.09E-08
1 .97E-06
1 .30E-05
2.31 E-03
6.37E-05
8.77E-05
2.37E-04
1 .59E-04
1 .39E-07
4.26E-07
1 .33E-04
7.19E-06
4.35E-05
5.63E-08
2.22E-06
2.19E-06
2.19E-06
2.05E-08
2.08E-06
9.79E-05
1 .86E-03
Explanation of Results
No difference
No difference
PRESTO results are slightly higher because of the short half-life of the radionuclide
RAGS/HHEM includes water ingestion, while PRESTO and RESRAD do not, RESRAD corrects soil ingestion for time indoors
No difference
No difference
PRESTO depletes the source before the radionuclide reaches the fish, so there is only one dominant pathway. RESRAD uses a
special calculation that maximizes C-14 concentration in plants. RAGS/HHEM maximizes all of these pathways
PRESTO results are slightly higher because of the short half-life of the radionuclide
PRESTO results are slightly higher because of the short half-life of the radionuclide
No difference
RAGS/HHEM includes water ingestion, while PRESTO and RESRAD do not
RAGS/HHEM includes water ingestion, while PRESTO and RESRAD do not, RESRAD corrects soil ingestion for time indoors
RAGS/HHEM includes water ingestion, while PRESTO and RESRAD do not, RESRAD corrects soil ingestion for time indoors
PRESTO results are slightly higher because of the short half-life of the radionuclide
No difference
No difference
RESRAD and PRESTO include air deposition for radionuclide concentration in plants, PRESTO includes surface erosion as a route
to fish ingestion.
No difference
No difference
No difference
PRESTO results are slightly higher because of the short half-life of the radionuclide
PRESTO does not include soil ingestion by cattle for radionuclide concentrations in meat
PRESTO results are slightly higher because of the short half-life of the radionuclide
RESRAD and PRESTO decay H-3 during transport, and PRESTO leaches radionuclides more slowly than RESRAD
PRESTO leaches radionuclides more slowly than RESRAD
No difference
PRESTO results are slightly higher because of the short half-life of the radionuclide
PRESTO results are slightly higher because of the short half-life of the radionuclide
No difference
RAGS/HHEM includes water ingestion, PRESTO overcompensates for correction factor
RAGS/HHEM includes water ingestion, PRESTO overcompensates for correction factor
No difference
PRESTO and RAGS/HHEM do not calculate ingrowth of Ac-227 +D, RAGS/HHEM includes water ingestion
No difference
PRESTO does not include soil ingestion by cattle for radionuclide concentrations in meat
RAGS/HHEM includes water ingestion, RESRAD corrects soil ingestion for time indoors
RAGS/HHEM includes water ingestion, RESRAD corrects soil ingestion for time indoors
RAGS/HHEM includes water ingestion, RESRAD corrects soil ingestion for time indoors
PRESTO and RAGS/HHEM do not include ingrowth of Am-241 , RAGS/HHEM includes water ingestion
RAGS/HHEM includes water ingestion, RESRAD corrects soil ingestion for time indoors
No difference
PRESTO does not calculate exposure to radon
-------
TABLE 3-10. COMPARISON OF MODEL RESULTS FOR THE GENERIC TEST SITE, ASSUMING RURAL RESIDENTIAL EXPOSURE*
Nuclide
Ra-226 (-Rn)
Ra-228 +D
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230 (+Rn)
Th-230 (-Rn)
Th-232 (+Rn)
Th-Sep (+Rn)
Th-Sep (-Rn)
Th-Series (+Rn)
Th-Series (-Rn)
TI-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
DU (+Rn)
DU (-Rn)
U-Sep (+Rn)
U-Sep (-Rn)
U-Series (+Rn)
U-Series (-Rn)
Zn-65
Risk Factor
RESRAD
2.38E-04
1.78E-04
2.46E-05
3.62E-05
7.32E-07
7.84E-09
8.06E-05
5.51 E-05
1 .68E-04
2.40E-05
2.11E-04
7.50E-05
2.95E-04
4.92E-04
3.48E-04
2.97E-04
2.93E-04
1 .90E-06
8.35E-05
1 .89E-05
1 .85E-05
2.41 E-05
1.75E-05
2.84E-05
3.04E-05
3.04E-05
4.81 E-05
4.81 E-05
1.17E-03
3.02E-04
1 .60E-04
PRESTO
2.28E-04
1.12E-04
1.27E-05
2. 71 E-05
3.36E-07
7.13E-09
9. 11 E-05
3.30E-05
1.12E-04
2.35E-05
4.58E-07
NC
4.69E-07
NC
NC
NC
NC
1 .85E-06
1.70E-06
2.14E-05
2.14E-05
2.45E-05
2.02E-05
3.26E-05
NC
NC
NC
NC
NC
NC
7.19E-05
RAGS/HHEM
2.25E-04
1 .46E-04
2.80E-05
3.56E-05
7.36E-07
1.81E-08
1.01E-04
6.89E-05
1 .85E-04
2.41 E-05
5.03E-07
NC
2.01 E-05
2.06E-04
1 .66E-04
3.52E-04
2.93E-04
3.72E-06
2.10E-05
1.27E-05
1.27E-05
2.06E-05
1 .20E-05
2.01 E-05
2.07E-05
2.07E-05
3.38E-05
3.38E-05
1 .94E-03
3.05E-04
1.76E-04
Explanation of Results
No difference
No difference
PRESTO results are slightly higher because of the short half-life of the radionuclide
PRESTO results are slightly higher because of the short half-life of the radionuclide
PRESTO leaches radionuclides more slowly than RESRAD, and Sm-1 47 does not reach groundwater in 1 000 years
RAGS/HHEM includes water ingestion
No difference
PRESTO leaches radionuclides more slowly than RESRAD
No difference
No difference
PRESTO does not calculate exposure to radon, RAGS/HHEM does not include ingrowth of Ra-226 (+Rn)
PRESTO and RAGS/HHEM were not used to perform this calculation
PRESTO and RAGS/HHEM do not include ingrowth of Ra-228+D, PRESTO does not calculate exposure to
PRESTO does not calculate exposure to radon
PRESTO was not used to calculate exposures from combinations of radionuclides
PRESTO does not calculate exposure to radon
PRESTO was not used to calculate exposures from combinations of radionuclides
RAGS/HHEM includes water ingestion
radon
PRESTO and RAGS/HHEM do not include ingrowth of Ra-228+D, PRESTO decays U-232 before it reaches groundwater
RESRAD and PRESTO include irrigation pathways for calculating radionuclide concentrations in plants
RESRAD and PRESTO include irrigation pathways for calculating radionuclide concentrations in plants
RESRAD and PRESTO include irrigation pathways for calculating radionuclide concentrations in plants
RESRAD and PRESTO include irrigation pathways for calculating radionuclide concentrations in plants
RESRAD and PRESTO include irrigation pathways for calculating radionuclide concentrations in plants
PRESTO does not calculate exposure to radon
PRESTO was not used to calculate exposures from combinations of radionuclides
PRESTO does not calculate exposure to radon
PRESTO was not used to calculate exposures from combinations of radionuclides
PRESTO does not calculate exposure to radon
PRESTO was not used to calculate exposures from combinations of radionuclides
No difference
NC
Not Calculated
-------
RAGS/HHEM does not consider the time required to transport radionuclides to groundwater.
All radionuclides are instantly placed in groundwater at maximum concentration without
accounting for transport time or radioactive decay. This means that radionuclides with high
Kd values—that would normally not reach groundwater—have a water ingestion component
added to the risk factor calculated by RAGS/HHEM. RAGS/HHEM calculates higher risk
factors for ten radionuclides—Am-241, Cm-243, Cm-244, Cm-248, Pu-238, Pu-239, Pu-240,
Pu-241, Pu-242, Sm-151, and Tl-204—because of this groundwater assumption.
PRESTO does not include a pathway for inhalation of radon, and was not used to calculate
results for eight radionuclides and combinations.
RESRAD currently corrects for soil ingestion for time spent indoors (a filtration factor is
included). This correction reduces the soil ingestion risk by a factor of four and causes
differences in the results for seven radionuclides—Am-241, Cm-244, Cm-248, Pu-238, Pu-
239, Pu-240, and Pu-242.
RESRAD and PRESTO include irrigation and air deposition of particulates as pathways for
estimating radionuclide concentration in plants while RAGS/HHEM does not include these
pathways. Cs-135 has a lower risk with RAGS/HHEM because of the lack of an air
deposition component, and U-233, U-234, U-235+D, U-236, and U-238 have lower risk
factors with RAGS/HHEM because of the lack of an irrigation pathway.
RESRAD and RAGS/HHEM include soil ingestion by cattle as a pathway for estimating
radionuclide concentration in meat. PRESTO calculates a risk factor for Fe-55 almost five
times lower than RESRAD because PRESTO does not include this pathway. PRESTO also
calculates a risk factor for Sm-147 that is half the risk factor calculated using RESRAD for
the same reason.
The calculation of the radionuclide concentration in groundwater is performed differently for
the three models and the differences can influence the results. The most dramatic example of
these differences is for H-3. The slow leaching of radionuclides from the soil by the PRESTO
code results in the maximum concentration in groundwater occurring in year 808 of the
simulation (see Table 2-5). H-3 has a twelve year half-life and decays long before the
groundwater concentration is maximized. PRESTO calculates a risk factor of 7.9xlO"9 based
on the slow leaching and short half-life. RAGS/HHEM instantly maximizes the
Review Draft - 9/26/94 3-28 Do Not Cite Or Quote
-------
concentration of H-3 in groundwater and calculates a risk factor of 1.3xlO"5—almost 1,600
times the risk calculated by PRESTO. RESRAD leaches H-3 from the soil quickly enough
that it does not decay before it reaches groundwater. Because RESRAD also depletes the
contaminated zone through evaporation, the risk factor calculated by RESRAD is S.OxlO"6,
which is four times smaller than RAGS/HHEM.
The difference in the leach rate for the models becomes smaller as the Kd becomes larger and
the radionuclide half-lives become longer. H-3, with a Kd value of zero and a short half-life,
is greatly influenced by the difference in leach rate. Results for 1-129, with a Kd value of 1
and a long half-life, vary by less than a factor of three between the models. Np-237+D, with a
Kd value of five and a long-half-life, shows almost no difference in the results of the three
models. Tc-99 and Sm-147 are the only other radionuclides with results affected by the leach
rate using base case Kd values.
The risk factors calculated by PRESTO for Ni-59 and Ni-63 are slightly higher than the risk
factors calculated by RAGS/HHEM because of the correction factor which adjusts for the
fraction of fodder that is contaminated. This correction factor is discussed in Chapter 2.
The difference in calculations for estimating radionuclide concentrations in surface water do
not influence any of the results for the generic test site, but there is potential for increased
exposure not included in the modeling. PRESTO includes erosion as a possible source of
surface water contamination. While the contribution of this pathway is negligible for fish
ingestion, as shown by the low percentage of lifetime risk in Tables 3-1 through 3-9, the
presence of risk from fish ingestion for Pu-242 and Th-232 without any risk from
groundwater is significant. This means when the surface water is contaminated, ingestion of
surface water could increase the risk from ingestion of meat and milk. This increase in risk is
estimated to be very small (less than 10%) and should not significantly change the results
reported here.
The results calculated by the three models are similar for many of the radionuclides. The
most significant changes are caused by the decay and ingrowth corrections, which at this time
only RESRAD applies to all of the radionuclides. The most significant change for a single
radionuclide is H-3, and this is caused by a combination of slow leach rate and short half-life
for the PRESTO calculation. RESRAD was selected for performing the calculations for the
reference sites because it calculates a more conservative result for H-3 and includes
corrections for ingrowth and decay of principle radionuclides.
Review Draft - 9/26/94 3-29 Do Not Cite Or Quote
-------
3.1.1.3 Sensitivity to Model User.
One of the major sources of uncertainty in the use of any model or computer code is the way
the user applies the code. There is often uncertainty in interpreting the proper input
parameters or understanding the code's user instructions. To study the potential importance of
this source of uncertainty, five individual modelers independently applied RESRAD to the
analysis of a real site to determine the RME. Four of the individuals obtained results within a
factor of 4 of each other—however, one obtained results which differed by several hundred-
fold from the others. The two primary reasons for these differences were misinterpretation of
data characterizing the site and a misunderstanding of how to use RESRAD. In addition, an
important source of uncertainty is the judgment and assumptions regarding the degree to
which daughter radionuclides are present at time zero of the analysis. The results of this study
underscore the importance of simplicity and user-friendliness in any site-specific
implementation model, and the need for extreme care in interpreting the meaning of site-
specific data.
3.1.2 Modeling Parameters
Table 3-11 lists the parameters used to model the generic test site and the values selected to
represent the characteristics of this site using RESRAD Version 5.19. The parameter values
used for the calculations were selected as realistic but conservative estimates of the conditions
at the generic test site for each of the three scenarios. The parameters are divided into two
groups: parameters describing the physical characteristics of the site and parameters
describing the exposure to an individual living or working on the site. The parameter values
used in the PRESTO calculations are listed in Appendix G along with an explanation of how
these values relate to the RESRAD values. The parameter values used for the RAGS/HHEM
calculations are listed in Appendix C with the modified RAGS/HHEM equations.
3.1.2.1 Physical Parameters Describing the Generic Test Site.
Figure 3-4 illustrates the primary physical characteristics of the generic test site used to derive
the generic site risk factors. Variants on these characteristics are examined in the sensitivity
analyses discussed in Section 3.1.3. The three hydrogeologic zones of interest are described
as follows:
Review Draft - 9/26/94 3-30 Do Not Cite Or Quote
-------
• Contaminated Zone: This zone is defined as an area of soil with radionuclide
contamination extending from the surface to a selected depth. Each
radionuclide considered is assumed to be uniformly distributed throughout this
soil volume at a concentration of 1 pCi/g to begin the simulation. A unit value
of 1 pCi/g was selected because all impacts are directly proportional to the
radionuclide concentration in the soil.
Unsaturated Zone: This zone is defined as soil extending from the bottom of
the contaminated zone to the top of the aquifer. Because this soil is outside the
contaminated area, it is assumed to be initially uncontaminated.
Aquifer: This area represents a groundwater resource that is assumed to supply
100 percent of the daily drinking water intake for onsite residents (i.e., 2 L/day)
and half of the drinking water intake for workers (i.e.., 1 L/day). Also, the
aquifer is assumed to be a source of water used to irrigate crops and feed
livestock. A well is assumed to be constructed onsite at the down-gradient
edge of the site. The aquifer is initially assumed to be uncontaminated.
Table 3-12 compares generic site (base case) and reference site characteristics (the reference
sites, which are generally representative of actual U.S. sites with soil contamination, are
described in Chapter 4). As shown in the table by the generic test site rankings—although
reference sites vary widely in size and complexity—the generic test site appears to represent a
reasonable base case, not a worst case, for most sites.
Review Draft - 9/26/94 3-31 Do Not Cite Or Quote
-------
Table 3-11. Generic Test Site — Base Case Analysis Values
RESRAD Version 5.01 Values
RESRAD
Menu
R02
R011
Parameter
Exposure Pathways
Pathway 1 — External Gamma
Pathway 2 — Inhalation
Pathway 3 — Plant Ingestion
Pathway 4 — Meat Ingestion
Pathway 5 — Milk Ingestion
Pathway 6 — Aquatic Foods
Pathway 7 — Drinking Water
Pathway 8 — Soil Ingestion
Pathway 9 — Radon
RESRAD
Default Value
Active
Active
Active
Active
Active
Active
Active
Active
Suppressed
Base Case Analysis Values
Suburban
Active
Active
Active
Suppressed
Suppressed
Suppressed
Active
Active
Active
Rural
Residential
Active
Active
Active
Active
Active
Active
Active
Active
Active
Commercial/
Industrial
Active
Active
Suppressed
Suppressed
Suppressed
Suppressed
Active
Active
Active
Notes
• Exposure pathways included
in the generic test site analysis
are generally consistent with
those recommended by EPA
for rural residential, suburban
and commercial/industrial
exposure scenarios. The
selection of exposure
scenarios is discussed in
Section 2.1.
• For completeness, the generic
test site analysis included four
additional suburban exposure
pathways: plant, meat, milk,
and aquatic food ingestion.
Contaminated Zone
Item 1: Area of Contaminated Zone
Item 2: Thickness of Contaminated Zone
Item 3: Length Parallel to Aquifer Flow
Item 4: Radiation Dose
Item 5: Elapsed Time
10,000 m2
2m
100m
30 mrem/yr
Oyr
10,000 m2
2m
113m
[Not applicable]
Oyr
10,000 m2
2m
113m
[Not
applicable]
Oyr
10,000 m2
2m
113m
[Not
applicable]
Oyr
• Values selected for items 1-3
are reasonable best estimates
based on sensitivity analyses
(Sections 3. 1.1 and 3.3).
• Item 4 refers to DOE's current
annual dose rate limit (i.e., 30
mrem/yr) for site restoration.
• Item 5 is a correction factor
for elapsed time since burial.
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R012
R013
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Initial Concentration
Item 1: Listed by Radionuclide
1 pCi/g
1 pCi/g
1 pCi/g
1 pCi/g
• All 67 radionuclides listed in
RESRAD 5.0 were included in
the base case analysis, except
Al-26,Au-195,Ca-41,Cf-
252, Gd-152, and Ge-68,
because published EPA
cancer slope factor values
were not available.
Cover and Contaminated Zone Hydrological Data
Item 1 : Cover Depth
Item 2: Density of Contaminated Zone
Item 3: Contaminated Zone Erosion Rate
Item 4: Contaminated Zone Total Porosity
Item 5: Contaminated Zone Effective Porosity
Item 6: Contaminated Zone Hydraulic Conductivity
Item 7: Contaminated Zone b parameter
Item 8: Evapotranspiration Coefficient
Item 9: Precipitation
Item 10: Irrigation Rate
Item 1 1 : Irrigation Mode [overhead or ditch]
Item 12: Runoff Coefficient
Item 13: Watershed Area for Nearby Stream or Pond
Item 14: Accuracy for Water/Soil Computation
Om
1.5 g/cm3
0.001 m/yr
0.4
0.2
10 m/yr
5.3
0.5
1 m/yr
0.2 m/yr
Overhead
0.2
1,000,000m2
0.001
Om
1.5 g/cm3
0.001 m/yr
0.485
0.2
227 m/yr
5.3
0.5
1 m/yr
0.2 m/yr
Overhead
0.2
1,000,000m2
0.001
Om
1.5 g/cm3
0.001 m/yr
0.485
0.2
227 m/yr
5.3
0.5
1 m/yr
0.2 m/yr
Overhead
0.2
1,000,000m2
0.001
Om
1.5 g/cm3
0.001 m/yr
0.485
0.2
227 m/yr
5.3
0.5
1 m/yr
0.2 m/yr
Overhead
0.2
1,000,000m2
0.001
• The default value of 0 meters
for item 1 means that a clean
soil layer was not assumed as
a cover for the contaminated
zone.
• Default values were used for
items 2, 3, 5 and 7-14 as
reasonable best estimates
based on sensitivity analyses
and RESRAD guidance (DOE
93a,ANL91).
• Alternate values were selected
as conservative estimates for
items 4 and 6 based on
lithology (silty-loam) and
RESRAD look-up tables
(DOE 93a).
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R014
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Saturated Zone Hydrological Data
Item 1: Density of Saturated Zone
Item 2: Saturated Zone Total Porosity
Item 3: Saturated Zone Effective Porosity
Item 4: Saturated Zone Hydraulic Conductivity
Item 5: Saturated Zone Hydraulic Gradient
Item 6: Saturated Zone b Parameter
Item 7: Water Table Drop Rate
Item 8: Well Pump Intake Depth
Item 9: Non-Dispersion Model or
Mass-Balance Model
Item 10: Well Pumping Model
1.5 g/cm3
0.4
0.2
100 m/yr
0.02
5.3
0.001 m/yr
10m
Non-
Dispersion
250 m'/yr
1.5 g/cm3
0.395
0.2
5,550 m/yr
0.02
4.05
0 m/yr
3m
Non-Dispersion
250 m3/yr
1.5 g/cm3
0.395
0.2
5,550 m/yr
0.02
4.05
0 m/yr
3m
Non-
Dispersion
250 m3/yr
1.5 g/cm3
0.395
0.2
5,550 m/yr
0.02
4.05
0 m/yr
3m
Non-
Dispersion
250 m3/yr
• Default values were used for
items 1, 3, 5, 9 and 10 as
reasonable best estimates
based on sensitivity analyses
and RESRAD guidance (DOE
93a,ANL91).
• Alternate values were selected
for items 2 and 4 based on
lithology (sand) and RESRAD
look-up tables (DOE 93).
• Alternate values were selected
for items 7 and 8 to minimize
dilution in the aquifer.
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R015
R016
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Uncontaminated and Unsaturated Strata Hydrological Data
Item 1: Number of Unsaturated Strata
Item 2: Thickness
Item 3: Soil Density
Item 4: Total Porosity
Item 5: Effective Porosity
Item 6: Soil Specific b Parameter
Item 7: Hydraulic Conductivity
1
4 m
1.5g/cm3
0.4
0.2
5.3
10 m/yr
1
2m
1.5g/cm3
0.485
0.2
5.3
227 m/yr
1
2m
1.5 g/cm3
0.485
0.2
5.3
227 m/yr
1
2m
1.5 g/cm3
0.485
0.2
5.3
227 m/yr
Distribution Coefficient and Leach Rates
Item 1 : Contaminated Zone KA
Item 2: Uncontaminated Zone KA
Item 3: Saturated Zone Kd
Item 4: Saturated Leach Rate
Item 5: Saturated Solubility
(See note)
(See note)
(See note)
0
0
(See note)
(See note)
(See note)
0
0
(See note)
(See note)
(See note)
0
0
(See note)
(See note)
(See note)
0
0
• Default values were used for
items 1, 3, 5 and 6 as
reasonable best estimates
based on sensitivity analyses
and RESRAD guidance (DOE
93a,ANL91).
• Alternate values were selected
for items 4 and 7 based on
lithology (silty-loam) and
RESRAD look-up tables
(DOE 93a).
• An alternate value was
selected for item 2 based on
the characteristics of the
reference sites (Section 3.1.1).
• Refer to Table 3- 1 3 for a
listing of the radionuclide
distribution coefficients (Kd
values) used in the RESRAD
generic test site base case
calculations.
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R017
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Inhalation and External Gamma Parameters
Item 1 : Inhalation Rate
Item 2: Mass Loading for Inhalation
Item 3: Dilution Length for Airborne Dust
(inhalation)
Item 4: Exposure Duration
Item 5A: Shielding Factors - Inhalation
Item 5B: Shielding Factors - External
Item 6A: Time Factors - Indoors
Item 6B: Time Factors - Outdoors
Item 7: Shape Factor (external gamma)
8,400 mVyr
0.0002 g/m3
3m
30 yr
0.4
0.7
0.5
0.25
1
7,300 mVyr
0.00000 15 g/m3
3m
30 yr
0.4
0.8
0.6
0.02
1
7,300 mVyr
0.0002 g/m3
3m
30 yr
0.4
0.8
0.6
0.02
1
7,300 mVyr
0.0002 g/m3
3m
25 yr
0.4
0.8
0.22
0.01
1
• Default values were used for
items 3, 5A and 7 as
reasonable best estimates
based on sensitivity analyses.
• Values selected for items 1
and 4 are based on EPA's
OSWER Directive 9285.6-03,
Human Health Evaluation
Manual, Supplemental
Guidance: "Standard Default
Exposure Factors" (March 25,
1991).
• The value selected for item
5B was taken from EPA's Risk
Assessment Guidance for
Super/and: Volume I - Human
Health Evaluation Manual,
PartB.
• Values selected for items 6A
and 6B are based on OSWER
Directive 9285.6-03 and on
EPA's Exposure Factors
Handbook, EPA/600/8-89/043
(March 1989).
• An alternate value was
selected for item 2 for
suburban exposures based on
EPA's Draft Guidance for
Soil Screening Level
Framework, (July 1994).
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R018
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Ingestion Pathway Data, Dietary Parameters
Item 1: Fruits, Vegetables and Grain Consumption
Item 2: Leafy Vegetables Consumption
Item 3: Milk Consumption
Item 4: Meat and Poultry Consumption
Item 5: Fish Consumption
Item 6: Other Seafood
Item 7: Soil Ingestion
Item 8: Drinking Water Intake
Item 9: Contamination Factor -
Drinking Water
Item 10: Contamination Factor -
Household Water
Item 1 1 : Contamination Factor -
Livestock Water
Item 12: Contamination Factor - Irrigation
Item 13: Contamination Factor - Aquatic Pond
Item 14: Contamination Factor -
Plant Food, Meat, and Milk
160 kg/yr
14 kg/yr
92 L/yr
63 kg/yr
5.4 kg/yr
0.9 kg/yr
36.5 g/yr
5 10 L/yr
1
1
1
1
0.5
RESRAD
Calculated
45.5 kg/yr
9.1 kg/yr
[Not applicable]
[Not applicable]
[Not applicable]
[Not applicable]
43.8 g/yr
730 L/yr
1
1
[Not applicable]
1
[Not applicable]
RESRAD
Calculated
122.5 kg/yr
13.3 kg/yr
184 L/yr
126 kg/yr
4.6 kg/yr
0 kg/yr
43.8 g/yr
730 L/yr
1
1
1
1
0.5
RESRAD
Calculated
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
36.5 g/yr
365 L/yr
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
• Alternate values were selected
for items 1-8 based on EPA,
DOE, and NRC guidance.
The selection of these values
is discussed in Section 3.1.2.
• Default values were used for
items 9-14 (contamination
factors) and the ingestion
rates were modified to
compensate for these
corrections.
• Items 3-6, 1 1 and 13 are not
applicable to suburban
exposure scenarios.
• Items 1-7 and 9-14 are not
applicable to
commercial/industrial
exposure scenarios.
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R019
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Ingestion Pathway Data, Non-Dietary Parameters
Item 1 : Livestock Fodder Intake for Meat
Item 2: Livestock Fodder Intake for Milk
Item 3: Livestock Water Intake for Meat
Item 4: Livestock Water Intake for Milk
Item 5: Livestock Intake of Soil
Item 6: Mass Loading for Soil Deposition
Item 7: Depth of Soil Mixing Layer
Item 8: Depth of Roots
Item 9: Ground Fractional Usage -
Drinking Water
Item 10: Ground Fractional Usage - Household
Usage
Item 1 1 : Ground Fractional Usage -
Livestock Water
Item 12: Ground Fractional Usage - Irrigation
68 kg/yr
55 kg/yr
50 L/yr
160 L/yr
0.5 kg/d
0.0001 g/m3
0.15m
0.9m
1
1
1
1
[Not applicable]
[Not applicable]
[Not applicable]
[Not applicable]
[Not applicable]
0.0001 g/m3
0.15m
0.9m
1
1
[Not applicable]
1
68 kg/yr
55 kg/yr
50 L/yr
160 L/yr
0.5 kg/d
0.0001 g/m3
0.15m
0.9m
1
1
1
1
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
[Not
applicable]
0.15m
[Not
applicable]
1
1
[Not
applicable]
[Not
applicable]
• Default values were used for
items 1-12 as reasonable best
estimates based on sensitivity
analyses and RESRAD
guidance (DOE 93a, ANL 91).
• Items 1-5 and 11 are not
applicable to suburban
exposure scenarios.
• Items 1-6, 8 and 11-12 are not
applicable to
commercial/industrial
exposure scenarios.
-------
Table 3-11. (Continued)
RESRAD Version 5.01 Values
RESRAD
Menu
R021
Parameter
RESRAD
Default Value
Base Case Analysis Values
Suburban
Rural
Residential
Commercial/
Industrial
Notes
Radon Parameters
Item 1: Cover Material Thickness
Item 2: Building Foundation Thickness
Item 3: Building Foundation Density
Item 4: Building Foundation Total Porosity
Item 5: Volumetric Water Content
Item 6: Effective Radon Diffusion Coefficient
Item 7: Contaminated Zone Radon
Diffusion Coefficient
Item 8: Radon Vertical Dimension of Mixing
Item 9: Average Annual Wind Speed
Item 10: Building Air Exchange Rate
Item 1 1 : Building Room Height
Item 12: Building Indoor Area Factor
Item 13. Foundation Depth Below
Ground Surface
Item 14: Radon Emanation Coefficient,
Rn-222
Om
0.15m
2.4 g/cm3
0.1
0.03
0.0000003
m2/s
0.000002 m2/s
2m
2 m/s
0.5 per hr
2.5m
0
1m
0.25
Om
0.15m
2.4 g/cm3
0.1
0.03
0.0000003 m2/s
0.000002 m2/s
2m
2 m/s
0.35 per hr
2.5m
0
1m
0.25
Om
0.15m
2.4 g/cm3
0.1
0.03
0.0000003 m2/s
0.000002 m2/s
2m
2 m/s
0.35 per hr
2.5m
0
1m
0.25
Om
0.15m
2.4 g/cm3
0.1
0.03
0.0000003 m2/s
0.000002 m2/s
2m
2 m/s
0.35 per hr
2.5m
0
1m
0.25
• Default values were used for
items 1-9 and 11-14 as
reasonable best estimates
based on sensitivity analyses
and RESRAD guidance (DOE
93a,ANL91).
• An alternate value was
selected for item 10 based on
EPA modeling for radon
exposures.
-------
Figure 3-4. Generic Test Site Characteristics
100m
100m
Contaminated Zone
Unsaturated Zone
2m
2m
Radionuclide Concentration = 1 pCi/g
Pattern of Contamination = Uniformly Distributed Soil Source
Contaminated Zone Area = 10,000 m2
Contaminated Zone Thickness = 2 m
Unsaturated Zone Thickness = 2 m
Infiltration Rate = 0.5 m/yr
Distribution Coefficients (Kd values) = Radionuclide Specific
Well Pump Intake Depth = 3 m
Review Draft - 9/26/94
3-40
Do Not Cite Or Quote
-------
Table 3-12. Comparison of Generic and Reference Site Characteristics
Parameter (units)
Contaminated
Zone Area (m2)
Contaminated
Zone Thickness
(m)
Unsaturated Zone
Thickness (m)
Infiltration Rate
(m/yr)
KH (cmVg)
Generic
Site
Values
10,000
2
2
0.5
Reference Site Values*
Range
Min
3,300
0.05
1
0
Max
5.9x10
2.5
100
0.54
5th%
6,260
0.05
1.9
0.05
50th%
4xl06
0.13
9.5
0.3
95th%
l.SxlO9
2.1
100
0.51
Generic
Site
Ranking
*
14%
94%
6%
93%
Radionuclide and site specific. See discussion in text.
* Values are taken from Tables 4-6 and 4-7.
The 10,000 m2 area of the contaminated zone was selected because it represents a site of
sufficient size for residents to build a home, maintain a garden, and raise livestock in small
numbers. In addition, one can assume that this size site would also permit industrial or
commercial activities. A site of this size constitutes an effective infinite volume source for
gamma-emitting radionuclides in soil when considering external radiation exposures. This
represents a conservative case for estimating external radiation exposures and risks.
The values for the contaminated zone thickness, unsaturated zone thickness, and infiltration
rate values were selected as conservative values at the 95th percentile based on the
distributions listed in Table 3-12. Values describing the hydrogeologic properties of the site
were selected from RESRAD look-up tables based on lithology. The contaminated and
unsaturated zones are assumed to be silty-loam. This is a common soil type and allows the
hydraulic conductivity to exceed the infiltration rate so that all of the water entering the
contaminated zone will percolate through the soil and exit the bottom of the unsaturated zone
into the aquifer. The aquifer is assumed to be sand with hydrogeologic properties able to
supply a small community with water. The well is placed at a very shallow point in the
aquifer, 3 m, to minimize the dilution of radionuclides in the aquifer. This provides a
conservative estimate of exposures to groundwater.
Review Draft - 9/26/94
3-41
Do Not Cite Or Quote
-------
The Kd values for each of the three hydrogeologic zones were assumed to be equal. This
single Kd value simplified the conceptual model of the site and allowed this parameter to be
included in the sensitivity analyses. The Kd values used in the base case analysis were
selected as the lowest value reported in Default Soil Solid/Liquid Partition Coefficients, Kd's,
for Four Major Soil Types: A Compendium., published in Health Physics. October 1990, by
Sheppard and Thibault. This is a comprehensive review of available Kd values and is the
most recent reference located for this report. The article included calculations for estimating
Kd values when literature values were not available.
Table 3-13 lists the Kd values used in the base case analysis. Also listed in the table are the
lowest literature value cited, the median value determined for the four soil types evaluated by
Sheppard and Thibault, the maximum value determined for the same four soil types, the
maximum value cited in the literature, and the default Kd values provided by DOE (RESRAD
guidance) and NRC (NUREG/CR-5512).
3.1.2.2 Exposure Parameters Describing the Generic Test Site.
The mathematical models, scenarios, and exposure pathways described in Chapter 2—in
addition to requiring input parameters characterizing the environment and the environmental
transport factors—require a broad array of input parameters and assumptions in order to
derive the doses and risks to the individual exposed to RME conditions at the generic test site.
These input parameters include:
• Inhalation and ingestion rates, including breathing rate and food and soil
ingestion rates
• Factors relating radionuclide exposure or intake rates to potential health
impacts, including dose and risk conversion factors and slope factors.
To the extent possible, standard default values for intake rates, exposure factors and
modifying factors (e.g., shielding correction factors) used in the pathway/risk model
calculations were taken from the following EPA guidance documents and directives, listed in
descending order of preference:
Review Draft - 9/26/94 3-42 Do Not Cite Or Quote
-------
Table 3-13. Distribution Coefficients (Kd's) Used in Generic Test Site Exposure
and Risk Modeling
Element
Ac
Ag
Am
Bi
C
Cd
Ce
Cl
Cm
Co
Cs
Eu
Fe
Gd
H
I
K
Mn
Lowest
Value
Reported In
Peer-
Reviewed
Literature
(Ref. 1)
240
2.7
1
30
5
1.3
40
1.5
93
0.07
0.2
240
1.4
240
0.04
0.04
16
0.2
Proposed EPA
Base Case
240
90
1,900
30
5
40
500
1.5
4,000
60
270
240
170
240
0
1
16
50
RESRAD
Version 5.04
Default
20
0
20
0
0
0
1,000
0.1
910
1,000
1,000
580
1,000
580
0
0
5.5
200
NUREG/CR-5512
Default
420
90
1,900
120
6.7
40
500
2
4,000
60
270
240
160
240
0
1
18
50
Proposed
EPA
Median
Value
1,000
150
9,000
130
14
320
5,700
7
6,000
780
1,100
1,000
410
1,000
15
3
71
170
Proposed
EPA High-
End Value
2,900
15,000
110,000
370
39
800
20,000
19
18,000
1,300
4,600
2,900
800
2,900
42
25
200
750
Highest
Value
Reported
In Peer-
Reviewed
Literature
(Ref. 1)
2,900
33,000
450,000
370
39
17,000
56,000
19
52,000
14,000
145,000
2,900
6,000
2,900
42
370
200
77,000
Basis for
Proposed
EPA
Base
Case*
R
E
E
R
E
E
E
R
E
E
E
R
E
R
M
E
R
E
-------
Table 3-13. Distribution Coefficients (Kd's) (continued)
Element
Na
Nb
Ni
Np
Pa
Pb
Pm
Pu
Ra
Ru
Sb
Sm
Sr
Tc
Th
Tl
U
Zn
Lowest
Value
Reported In
Peer-
Reviewed
Literature
(Ref. 1)
44
110
60
0.16
110
4.5
240
11
57
5
45
240
0.01
0.0029
207
20
0.03
0.1
Proposed EPA
Base Case
44
110
150
5
110
270
240
550
500
55
45
240
15
0.1
3,200
20
15
200
RESRAD
Version 5.04
Default
10
0
1,000
204
50
100
580
2,000
70
0
0
0
30
0
60,000
0
50
0
NUREG/CR-5512
Default
76
160
400
5
510
270
240
550
500
55
45
240
15
0.1
3,200
390
15
200
Proposed
EPA
Median
Value
190
480
530
40
480
8,300
1,000
1,500
2,100
900
480
1,000
65
0.6
4,500
89
220
1,500
Proposed
EPA High-
End Value
540
1,300
1,100
1,200
1,300
22,000
2,900
5,100
9,100
66,000
1,300
2,900
150
1
89,000
250
1,600
2,400
Highest
Value
Reported
In Peer-
Reviewed
Literature
(Ref. 1)
540
1,300
4,700
2,600
1,300
59,000
2,900
300,000
530,000
87,000
1,300
2,900
32,000
340
13,000,000
250
400,000
100,000
Basis for
Proposed
EPA
Base
Case*
R
E
E
E
R
E
R
E
E
E
E
R
E
E
E
R
E
E
-------
Table 3-13. Distribution Coefficients (Kd's) (continued)
NOTES:
R The base case value is calculated based on the plant-soil uptake factor using the method described by Sheppard and Thibault (Ref. 1). The
coefficient for sand was used to calculate the base case K d value.
E The base case value is the minimum geometric mean Kd value based on lithology published by Sheppard and Thibault (Ref. 1).
M The base case value is set equal to 0 as a conservative estimate based on the assumption that tritium is tritiated water and is mobile (Ref. 2 & 3).
REFERENCES:
(1) Sheppard, M.I. and D.H. Thibault, 1990, Default Soil Solid/Liquid Partition Coefficients, K ^, for Four Major Soil Types: A Compendium , Health
Physics. 59(41:471-482.
(2) Yu, C. et al., 1993, Manual for Implementing Residual Radioactive Material Guidelines Using RESRA D, Version 5.0 , , ANL/ES-160,
DOE/CH/8901, Argonne National Laboratory, Argonne, IL. Note: Radionuclide Kd values are provided in: Yu, C. et al, 1993, Data Collection
Handbook to Support Modeling the Impacts of Radioactive Material in Soil , ANL/EAIS-8, Argonne National Laboratory, Argonne, IL.
(3) Kennedy, W.E. and D.L. Strenge, 1992, Residual Radioactive Contamination From Decommissioning, Technical Basis for Translating
Contamination Levels to Annual Total Effective Dose Equivalent - Final Report , NUREG/CR-5512, PNL-7994, Vol. 1, Pacific Northwest
Laboratory, prepared for the U.S. Nuclear Regulatory Agency.
-------
• Human Health Evaluation Manual, Supplemental Guidance: "Standard Default
Exposure Factors," Office of Solid Waste and Emergency Response, OSWER
Directive 9285.6-03, March 25, 1991 (EPA 91b).
• Exposure Factors Handbook, Office of Health and Environmental Assessment,
EPA/600/8-89/043, March 1989 (EPA 89c).
• Risk Assessment Guidance for Super fund, Volume I: Human Health Evaluation
Manual (Part A, Baseline Risk Assessment), EPA Office of Emergency and
Remedial Response, EPA/540/1-89/002, 1989 (EPA 89a).
• Risk Assessment Guidance for Super fund, Volume I: Human Health Evaluation
Manual (Part B, Development of Risk-Based Preliminary Remediation Goals),
Interim Final, OERR Publication 9285.7-01B, October 1991 (EPA 91a).
Health Effects Assessment Summary Tables, OHEA ECAO-CIN-821, March
1992(EPA92b).
In the absence of specific guidance from EPA, values were taken from the following DOE or
NRC documents, in no specific order of preference.
• Manual for Implementing Residual Radioactive Material Guidelines Using
RESRAD, Version 5.0, prepared by Argonne National Laboratory for the U.S.
Department of Energy, September 1993 (Working Draft) (DOE 93a).
• Data Collection Handbook to Support Modeling the Impacts of Radioactive
Material in Soil, ANL/EAIS-8, prepared by Argonne National Laboratory for
the U.S. Department of Energy, April 1993 (ANL 93b).
• Residual Radioactive Contamination From Decommissioning: Technical Basis
for Translating Contamination Levels to Annual Total Effective Dose
Equivalent, prepared by W.E. Kennedy, Jr., and D.L. Strenge, Battelle Pacific
Northwest Laboratory for the U.S. Nuclear Regulatory Commission,
NUREG/CR-5512, October 1992 (Final Report) (NRC 92b).
Furthermore, in the absence of specific guidance from either EPA, DOE, or NRC, values were
selected from a range of factors published in the open literature.
Exposure duration for the suburban and rural residential scenarios is set at 30 years and EPA's
1994 30-year cancer incidence slope factors were used for calculating the results. The
exposure duration for commercial/industrial exposures is set at 25 years and uses the
Review Draft - 9/26/94 3-46 Do Not Cite Or Quote
-------
same slope factors. RESRAD Version 5.19 default dose conversion factors were used for the
dose calculations because dose conversion factors for several of the associated radionuclides
were not included in Federal Guidance Numbers 11 and 12 (EPA 88c, EPA 93d). The values
for exposure duration are taken from HHEM Supplemental Guidance (EPA 91b). Appendix
B contains tables listing the slope factors and dose conversion factors used in these
calculations.
External Gamma Radiation Parameters. The external shielding factor is the ratio of the
external gamma radiation level indoors to the radiation level outdoors. The value of 0.8 was
taken from RAGS/HHEM, Part B (EPA 91a). Values for the amount of time spent indoors
and outdoors each day for an individual are taken from H HEM Supplemental Guidance
(EPA 9la) and Exposure Factors Handbook (EPA 89c). The shape factor is used by
RESRAD to correct for a non-circular shaped contaminated area on the basis of an ideally
circular zone. The shape factor for a circle and for sites with an area greater than 1,200 m2 is
one. The generic test site for RESRAD is assumed to be a circle with an area of 10,000 m2,
thus the shape factor is one.
Inhalation Parameters. The inhalation rate is the volume of air inhaled by an individual in
one year. The value of 7,300 m3/yr is taken from HHEMSupplemental Guidance (EPA 91b).
The mass loading for inhalation is the quantity of contaminated dust contained in each m3 of
air. The value of 1.5xlO"6 g/m3 is taken from Draft Guidance for Soil Screening Level
Framework (EPA 94) as a reasonable quantity for suburban exposures. A larger value of
2xlO"4 g/m3 was selected for rural residential and commercial/industrial scenarios where larger
quantities of dust may potentially be suspended in air. This value was selected from the Data
Collection Handbook (ANL 93b). The shielding factor for inhalation is the ratio of quantity
of dust in indoor air to the quantity of dust in outdoor air, and accounts for filtration of indoor
air. The value of 0.4 was taken from the Data Collection Handbook (ANL 93b).
Ingestion Pathway Dietary Parameters. These parameters refer to the quantity of food
consumed by an individual in one year. RESRAD divides food intake into eight groups:
• Fruits, non-leafy vegetables, and grains
• Leafy vegetables
Milk
Review Draft - 9/26/94 3-47 Do Not Cite Or Quote
-------
• Meat and poultry
• Fish
• Other seafood
Soil
Water
The value entered into the program is assumed to be the total quantity of that food group
consumed each year. Contamination factors are applied to each group to correct for the
fraction of food that is contaminated.
The RESRAD contamination factors for plants, meat, and milk obtained from the site are
calculated internally by the program. For the base case analysis these correction factors all
equal 0.5. The correction factor for fish is also set at 0.5, while the correction factor for water
use (drinking, household, livestock, and irrigation) is set at one. This means 50% of the food
consumed by an individual living on the site is contaminated and 100% of the water used by
an individual on the site is contaminated.
The Exposure Factors Handbook (EPA 89c) lists the quantity of contaminated homegrown
vegetables at 50 g/day typical and 80 g/day reasonable worst case. Contaminated fruit
consumption is listed at 28 g/day typical and 42 g/day worst case. EPA does not break out
leafy vegetables or grains as separate categories. A mean value of 40 g/day (± 40 g/day) for
leafy vegetables can be calculated based on Table 2-9 in the Exposure Factors Handbook
(EPA 89c). This table also indicates that about 26% of homegrown vegetables are leafy and
74% are non-leafy. DOE recommends a value of 38 g/day in the Data Collection Handbook
(ANL 93b), with 50% of the leafy vegetables assumed to be contaminated. This gives a value
of 19 g/day of contaminated leafy vegetables. The Data Collection Handbook (ANL 93b)
also lists 53 g/day for contaminated grains.
EPA lists a typical contaminated milk consumption rate of 0.16 L/day, and a reasonable
maximum rate of 0.23 L/day (EPA 89c). DOE recommends a slightly more conservative
estimate of 0.25 L/day of contaminated milk in the Data Collection Handbook (ANL 93b).
The meat consumed by and individual living on the site is assumed to be beef. EPA estimates
that 75 g/day is a reasonable worst case estimate for contaminated beef consumption (EPA
89c). The Data Collection Handbook recommends a higher value of 173 g/day to account for
consumption of other types of meat as well as beef.
Review Draft - 9/26/94 3-48 Do Not Cite Or Quote
-------
The fish obtained from the generic test site are assumed to be fresh water fish living in the
surface water body on the site. The Exposure Factors Handbook lists a consumption rate of
6.5 g/day for non-marine fish consumption. DOE recommends a value of 7.5 g/day for
contaminated fish consumption and 1.3 g/day for other seafood in the Data Collection
Handbook (ANL 93b).
The Exposure Factors Handbook (EPA 89c) lists 2 L/day as a reasonable worst case for
drinking water consumption. DOE recommends 1.4 L/day as a typical drinking water
consumption rate in the Data Collection Handbook (ANL 93b).
EPA recommends a soil ingestion rate of 0.2 g/day for children up to 6 years of age, and a
rate of 0.1 g/day for adults in the Exposure Factors Handbook (EPA 89c). Applying these
recommendations for a 30 year exposure period (6 years at 0.2 g/day and 24 years at 0.1
g/day) a lifetime average soil consumption rate of 0.12 g/day is obtained.
Using the consumption rates listed above, annual intake values for the eight ingestion groups
were calculated for input in the RESRAD calculations. Separate values are calculated for
each exposure scenario.
For the suburban scenario, the fruit, vegetable, and grain ingestion rate was calculated
assuming a residence with a small garden. Using EPA's values of 37 g/day (200 g/day
ingested x 0.25 contaminated fraction x 0.74 non-leafy vegetable fraction) for non-leafy
vegetables and 28 g/day for fruits, a value of 22.8 kg/year is calculated. Applying the DOE
contamination factor of 0.5, a total ingestion rate of 45.6 kg/year is calculated. The leafy
vegetable consumption rate of 9.2 kg/year is similarly calculated (200 g/day total ingested x
0.25 contaminated fraction x 0.26 leafy vegetable fraction/0.5 RESRAD contamination
factor). There is no milk or meat produced on-site for the suburban scenario, so the ingestion
rates are zero. There are no fish consumed on-site, thus seafood is not considered for this
scenario. Soil ingestion is based on EPA's rate of 0.12 g/day, which is set at 43.8 g/yr. The
water ingestion rate of 2 L/day is used to calculate the annual water ingestion rate of 730 L/yr.
The rural residential scenario assumes that the site is used to grow plants for food and raise
cows for food and milk. A surface water body on the site serves as a supply of fresh-water
fish. Fruit, non-leafy vegetable, and grain consumption assumes the reasonable worst case
Review Draft - 9/26/94 3-49 Do Not Cite Or Quote
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values for vegetables and fruits recommended by EPA added to the DOE value for grains (80
g/day + 42 g/day + 53 g/day). A value of 122.5 kg/yr is calculated for total consumption of
these plants. The leafy vegetable consumption rate is based on DOE's value of 19 g/day,
which gives a total consumption rate of 13.3 kg/yr. Contaminated milk is obtained from the
site, and DOE's value of 0.25 L/day was used to calculate a total consumption rate of 184
L/yr. The consumption rate for meat is similarly set at 126 kg/yr using DOE's recommended
value of 173 g/day. EPA's value of 6.5 g/day for fresh water fish is used to calculate the total
ingestion value of 4.6 kg/yr. No seafood was consumed in this scenario. The drinking water
and soil ingestion rates are the same as the values used for the suburban scenario.
The commercial/industrial scenario assumes that an individual works on the site. As a
commercial or industrial facility, no food or animals are raised on the site. The ingestion rates
for plant, meat milk, and fish ingestion are all zero. The individual is assumed to spend half
their waking hours on-site, so the drinking water rate and soil ingestion rate are set equal to
half of EPA's recommended values, 1 L/day of water and 0.05 g/day of soil. These values are
used to calculate the water ingestion rate of 250 L/yr (1 L/day x 250 days/yr) and the soil
ingestion rate of 12.5 g/yr (0.05 g/day x 250 days/yr).
Ingestion Pathway Non-Dietary Parameters. There are several non-dietary parameters
required for the RESRAD calculations. These parameters include ingestion parameters for
animals and transfer factors for soil-to-plant, plant-to-meat, plant-to-milk, and surface water-
to-fish. Currently EPA does not provide any guidance for these parameters. Values used in
the RESRAD calculations were obtained from two sources:
• Data Collection Handbook to Support Modeling the Impacts of Radioactive
Material in Soil., ANL/EAIS-8, prepared by Argonne National Laboratory for
the U.S. Department of Energy, April 1993 (ANL 93b).
• Manual for Implementing Residual Radioactive Guidelines Using RESRAD,
Version 5.0, Working Draft, ANL/EAD/LD-2, prepared by Argonne National
Laboratory for the U.S. Department of Energy, September 1993 (DOE 93a).
The parameter values used for the RESRAD calculations are provided in Table 3-11.
Review Draft - 9/26/94 3-50 Do Not Cite Or Quote
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3.1.3 Sensitivity Analysis
Sensitivity analyses were performed on key parameters that were used in model calculations
to derive soil cleanup concentrations using RESRAD Version 5.19. These parameters
included: (1) area of the contaminated zone, (2) thickness of the contaminated zone, (3)
infiltration rate, (4) distribution coefficients (Kd values), and (5) thickness of the unsaturated
zone. The purpose of these analyses was to determine the sensitivity of generic radionuclide-
specific soil cleanup concentrations to variations in model input values.
3.1.3.1 Method
3.1.3.1.1 Modified Parameters and Parameter Values. Table 3-14 lists the parameters and
corresponding input values that were varied for use in the sensitivity analyses. These
parameters define key assumptions concerning specific characteristics of the generic test site
that have a direct impact on the derivation of soil cleanup concentrations. To determine this
impact, values for each parameter were varied from default values used in the base case
analysis (see Figure 3-4) as follows:
• Area of the Contaminated Zone/Length Parallel to Aquifer Flow: Values were
varied simultaneously in discrete pairs, with the value assigned for area ranging
by factors of 100 times lower to 1,000 times higher than the default value of
10,000 m2 used in the base-case calculations.
• Thickness of the Contaminated Zone: Values were varied by factors of 100
times lower to 1.5 times higher than the default value of 2 m used in the
base-case calculations.
• Infiltration Rate: Values were varied by factors of 500 times lower to 4 times
higher than the default value of 0.5 m/yr used in the base-case calculations.
Distribution Coefficients: Values were varied for each radionuclide
individually (see Table 3-13). In all cases, radionuclide-specific Kd values used
in the sensitivity analyses were higher than those assigned as default values.
• Thickness of the Unsaturated Zone: Values were varied from 0 to 50 m. A
default value of 2 m was used in the base-case calculations.
Review Draft - 9/26/94 3-51 Do Not Cite Or Quote
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Table 3-14. Modified Parameters and Input Values Used in Sensitivity Analyses
Parameter
Area of Contaminated Zone (m2) /
Length Parallel to Aquifer Flow (m)
Thickness of the Contaminated Zone (m)
Infiltration Rate (m/yr)
(See the equation below)
Distribution Coefficients (Kd: cmVg)
Unsaturated Zone Thickness (m)
Base Case Values
Area Length
10,000 113
2
0.5
(See Table 3-13)
2
Modified Values
Area Length
100 11
1,000 36
100,000 357
1,000,000 1,128
10,000,000 3,568
0.02
0.1
0.2
1
3
0.001
0.025
0.1
1
2
(See Table 3-13)
0
0.5
1
10
100
Infiltration Rate (m/yr) = (1 - CE)[(1 - CR)PR + IRR]
Where
IR
CE
CR
PR
IRR
Infiltration Rate (m/yr)
Evaporation Coefficient (unitless)
Runoff Coefficient (unitless)
Precipitation Rate (m/yr)
Irrigation Rate (m/yr)
IR =
CE =
CR =
PR =
IRR =
0.001
0.975
0.05
0.1
1
0.025
0.975
0.33
0.3
0.8
0.1
0.9
0
0.5
0.5
0.5
0.5
0.2
1
0.2
1
0.1
0.145
1.3
0
2
0
0
2
0
Review Draft - 9/26/94
3-52
Do Not Cite Or Quote
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Calculational Approach. Calculations were performed using the RESRAD Version 5.19
computer code assuming the rural residential exposure scenario. Consistent with this
scenario, nine exposure pathways were evaluated:
• External radiation exposure from photon-emitting radionuclides in soil
• Inhalation of resuspended soil and dust containing radionuclides
• Inhalation of radon (Rn-222 and Rn-220) and radon decay products from soil
containing radium (Ra-226 and Ra-224)
• Incidental ingestion of soil containing radionuclides
Ingestion of drinking water containing radionuclides transported from soil to
potable groundwater sources
• Ingestion of home-grown produce (i.e., fruits and vegetables) contaminated
with radionuclides taken up from soil
Ingestion of meat (i.e., beef) containing radionuclides taken up by cows grazing
on contaminated plants (i.e., fodder)
• Ingestion of milk containing radionuclides taken up by cows grazing on
contaminated plants (i.e., fodder)
Ingestion of locally caught fish containing radionuclides
Input values for each selected parameter were varied individually and systematically over the
ranges shown in Tables 3-13 and 3-14, while holding all other parameter values constant.
With each variation in the parameter value and for each radionuclide considered, RESRAD
calculated estimates of lifetime risk per pCi/g and soil concentrations (in pCi/g) corresponding
to the year of maximum risk. This process was repeated iteratively in a series of runs for each
radionuclide and each parameter. Including the base case calculations, 23 RESRAD runs
were performed for each radionuclide, as follows:
Six runs for contaminated zone area calculations (i.e., at 100, 1,000, 10,000,
100,000, 1,000,000 and 10,000,000 m2), plus
• Six runs for the contaminated zone thickness calculations (i.e., at 0.02, 0.1, 0.2,
1, 2 and 3 m), plus
Review Draft - 9/26/94 3-53 Do Not Cite Or Quote
-------
• Six runs for the infiltration rate calculations (i.e., at 0.001, 0.025, 0.1, 0.5, 1
and 2 m/yr), plus
Five runs for the Kd calculations (at low-, base case, mid-1-, mid-2-, and high-
end values), plus
• Five runs for the Unsaturated Zone Thickness calculations (i.e., at 0, 1,2, 10
and 100m)
A total of 1,708 RESRAD runs were required to complete all sensitivity analyses for the 61
radionuclides considered in the calculations. To deal with this large number of runs, five
computer programs (one each for the five parameters investigated) were written and used to
automate the process of changing parameter values and re-running RESRAD calculations.
These programs greatly reduced analysis times and facilitated data retrieval. However,
numerous hand calculations and manual RESRAD runs were also made to ensure all
automated calculations were performed correctly.
3.1.3.2 Results
The results of the sensitivity analyses for each of the five parameters appear in tabular form in
Appendix H, and are summarized below. The results listed in the tables are calculated as
radionuclide soil concentrations (RSCs) corresponding to a lifetime risk of IxlO"4. The RSCs
vary inversely with the risk factors.
Contaminated Zone Area. The results of sensitivity analyses on contaminated zone area
and thickness are summarized in Table 3-15.
The table illustrates that risk factors vary depending on the assumptions made regarding the
area of the contaminated zone. However, some general trends are observed when the data are
considered as a whole. The results indicate that for most radionuclides:
• the RSC will increase by a factor of approximately 10 when the area of the
contaminated zone decreases by a factor of 100 from the base case (i.e., from
10,000 to 100m2)
Review Draft - 9/26/94 3-54 Do Not Cite Or Quote
-------
Table 3-15. RESRAD Parameter Sensitivity Analysis: Contaminated Zone Area
Nuclide
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
Cl-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241 +D
Pu-242
Pu-244 +D
Ra-226 +D
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10" Risk Level
3
1
0.3
90
12
1
1
11
22
0.1
21
125
26
16
0.4
1
40
1
1
1
60
6,761
51
34
0.1
2
1
0.4
1
897
285
1
3
3
4,120
101
104
104
3,076
108
1
0.1
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the Contaminated Zone Area (nf)
100
2.04
1.95
1.90
2.86
1.92
1.84
150.17
10.76
1.92
41.08
1.80
3.03
3.16
2.02
1.91
2.11
30.55
2.35
1.82
1.82
1.84
51.53
1.84
11.12
14.27
5.11
1.86
1.94
1.82
25.69
25.70
8.49
3.08
10.97
12.74
2.97
2.97
2.96
2.86
2.96
1.83
1.52
1,000
1.05
1.11
1.09
1.04
1.06
1.06
5.24
1.09
1.06
4.11
1.06
1.03
1.03
1.12
1.09
1.17
3.06
1.26
1.06
1.06
1.06
5.28
1.06
2.68
4.03
1.73
1.06
1.12
1.06
2.57
2.57
2.65
1.41
1.11
1.40
1.05
1.05
1.05
1.04
1.05
1.06
1.02
10,000
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
100,000
1
0.95
0.97
0.98
1
1
0.22
0.92
1
0.54
1
0.99
0.99
0.94
0.97
0.90
0.57
0.85
1
1
0.99
0.53
1
0.40
0.28
0.69
1
0.95
1
0.60
0.60
0.37
0.60
0.90
0.76
0.97
0.97
0.97
0.98
0.97
1
0.97
1,000,000
1
0.95
0.97
0.98
1
1
0.07
0.92
1
0.54
1
0.98
0.98
0.94
0.97
0.90
0.57
0.85
1
1
0.99
0.53
1
0.28
0.17
0.41
1
0.95
1
0.60
0.60
0.22
0.45
0.90
0.76
NC
0.96
0.96
0.97
0.96
1
0.90
10,000,000
1
0.95
0.97
0.98
1
1
0.01
0.92
1
0.54
1
0.98
0.98
0.94
0.97
0.90
0.22
0.85
1
1
0.99
0.53
1
0.27
0.11
0.08
1
0.95
1
0.50
0.60
0.13
0.34
0.90
0.76
0.96
0.96
0.96
0.97
0.96
1
0.74
Review Draft - 9/26/94
3-55
Do Not Cite Or Quote
-------
Table 3-15. RESRAD Parameter Sensitivity Analysis: Contaminated Zone Area
Nuclide
Ra-228 +D
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Tl-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
Zn-65
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10" Risk Level
1
4
3
137
12,752
1
2
1
4
0.5
0.3
53
1
5
5
4
6
4
1
Average Ratio =
Minimum Ratio =
Maximum Ratio =
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the Contaminated Zone Area (nf)
100
2.08
2.20
1.82
9.00
13.11
15.63
10.25
1.82
1.88
1.60
2.06
12.14
1.07
9.59
9.72
5.27
9.73
8.59
4.55
9.59
1.07
150.17
1,000
1.08
1.07
1.06
2.11
1.40
1.56
1.85
1.06
1.06
1.03
1.08
1.31
0.62
2.92
2.94
2.19
2.94
2.78
2.03
1.66
0.62
5.28
10,000
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
100,000
0.98
0.97
1
0.58
0.76
0.71
0.47
1
1
0.96
0.98
0.79
1.05
0.36
0.36
0.41
0.36
0.37
0.65
0.80
0.22
1.05
1,000,000
0.96
0.97
1
0.55
0.76
0.71
0.31
1
1
0.89
0.96
0.79
1.17
0.22
NC
0.26
0.22
0.23
0.65
0.78
0.07
1.17
10,000,000
0.91
0.97
1
0.37
0.76
0.71
0.22
1
1
0.72
0.91
0.79
0.98
0.18
0.18
0.21
0.18
0.18
0.65
0.73
0.01
1.00
Notes:
(1) Sensitivity analyses were performed using the DOE RESRAD computer code (Version 5.19). See text for a discussion of
these analyses and the assumptions used in the calculations.
(2) The double-line column, containing ratio values equal to one, represents a comparison with the base case value. Shaded
boxes indicate calculated radionuclide soil concentrations that do not differ from the base case concentation by more that
0.1%, i.e. three decimal places.
(3) The following parameter values were assumed for the base case, generic site analysis:
*Contaminated Zone Area = 10,000m2;
*Contaminated Zone Thickness = 2 m;
* Infiltration Rate = 0.5 m/yr;
*Kd = radionuclide specific; and
*Uncontaminated, Unsaturated Zone Thickness = 2 m.
NC= Not calculated. RESRAD program error encountered during calculation.
Review Draft - 9/26/94
3-56
Do Not Cite Or Quote
-------
• the RSC will increase by a factor of approximately 2 when the area decreases
by a factor of 10 (i.e., from 10,000 to 1,000 m2)
the RSC will decrease slightly (by a factor of 0.8) when the area increases in
size by a factor of 10 or 100 (i.e., from 10,000 to 100,000 or 1,000,000 m2)
• the RSC will decrease slightly (by a factor of 0.7) when the area increases in
size by a factor of 1,000 (i.e., from 10,000 to 10,000,000 m2)
Contaminated Zone Thickness. The results of the sensitivity analyses on contaminated
zone thickness are summarized in Table 3-16.
The table illustrates that the risk factors vary depending on the assumptions made regarding
the area of the contaminated zone. However, some general trends are observed when the data
are considered as a whole. The results indicate that for most radionuclides:
• the RSC will increase by a factor of approximately 100 when the thickness
decreases by a factor of 100 from the base case (i.e., from 2 to 0.02 m)
• the RSC will increase by a factor of approximately 6 when the thickness
decreases by a factor of 20 from the base case (i.e., from 2 to 0.1 m)
• the RSC will remain relatively constant when the thickness equals or exceeds 1
meter
Infiltration Rate. The results of sensitivity analyses on infiltration rate are provided in Table
3-17.
The results indicate that for most radionuclides:
• the RSC will increase by a factor of approximately 3 when the infiltration rate
decreases by a factor of 500 from the base case (i.e., from 0.5 to 0.001 m/yr)
the RSC will increase by a factor of approximately 2 when the infiltration rate
decreases by a factor of 20 from the base case (i.e., from 0.5 to 0.025 m/yr)
• the RSC will remain relatively constant at infiltration rates above 0.1 m/yr.
Review Draft - 9/26/94 3-57 Do Not Cite Or Quote
-------
Table 3-16. RESRAD Parameter Sensitivity Analysis: Contaminated Zone Thickness
Nuclide
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
Cl-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241 +D
Pu-242
Pu-244 +D
Ra-226 +D
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
3
1
0.3
90
12
1
1
11
22
0.1
21
125
26
16
0.4
1
40
1
1
1
60
6,761
51
34
0.1
2
1
0.4
1
897
285
1
3
3
4,120
101
104
104
3,076
108
1
0.1
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the Contaminated Zone Thickness (n)
0.02
5.04
4.74
5.28
9.29
3.48
4.56
44.90
42.93
5.58
44.93
3.56
14.07
14.48
3.27
5.52
5.29
27.86
5.79
5.38
5.24
2.58
8.89
2.57
65.29
12.85
14.49
5.22
5.37
4.81
29.70
29.71
13.35
37.17
33.64
17.77
13.53
13.52
13.51
55.76
13.48
4.60
33.44
0.1
1.55
1.47
1.56
2.39
1.27
1.42
8.98
8.75
1.62
8.98
1.23
2.82
2.90
1.26
1.60
1.60
5.57
1.73
1.56
1.53
1.10
1.78
1.10
13.06
2.75
3.71
1.54
1.58
1.45
5.94
5.94
2.87
7.68
6.73
3.63
2.71
2.71
2.71
4.20
2.70
1.42
9.34
0.2
1.20
1.14
1.16
1.64
1.08
1.10
4.49
4.42
1.19
4.49
1.03
1.78
1.82
1.11
1.18
1.21
3.15
1.30
1.15
1.14
1.02
1.17
1.01
6.80
1.73
2.38
1.15
1.17
1.11
3.31
3.31
1.82
4.58
3.64
2.22
1.72
1.71
1.71
1.89
1.71
1.10
6.62
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0.60
0.93
1
1
1
1
1
1
0.91
0.70
1
1
1
1
1
0.99
1
1
0.22
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0.90
0.98
1
1
1
1
1
1
0.97
0.88
1
1
1
1
1
1
1
1
0.96
Review Draft - 9/26/94
3-58
Do Not Cite Or Quote
-------
Table 3-16. RESRAD Parameter Sensitivity Analysis: Contaminated Zone Thickness
Nuclide
Ra-228 +D
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Tl-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
Zn-65
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
1
4
3
137
12,752
1
2
1
4
0.5
0.3
53
1
5
5
4
6
4
1
Average Ratio =
Minimum Ratio =
Maximum Ratio =
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the Contaminated Zone Thickness (n)
0.02
7.93
5.28
4.27
28.77
18.25
42.75
22.01
6.83
5.94
5183.18
22.65
34.01
53.43
13.02
12.97
10.09
12.97
13.35
10.84
101.66
2.57
5183.18
0.1
1.97
1.64
1.36
5.75
3.67
8.55
4.55
1.82
1.66
165.59
2.59
7.80
2.03
2.79
2.78
3.35
2.78
2.86
3.01
5.11
1.10
165.59
0.2
1.36
1.27
1.08
3.62
2.23
4.34
2.74
1.26
1.20
48.79
1.52
4.15
1.08
1.75
1.75
2.10
1.75
1.80
2.06
2.88
1.01
48.79
1
1
1
1
0.74
1
1
0.81
1
1
0.19
0.99
1
0.68
0.93
0.93
0.87
0.93
0.92
1
0.94
0.19
1.00
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
1
1
1
0.92
1
1
0.92
1
1
0.59
1
1
0.87
0.97
0.97
0.95
0.97
0.97
1
0.98
0.59
1.00
Notes:
(1) Sensitivity analyses were performed using the DOE RESRAD computer code (Version 5.19). See text for a discussion of
these analyses and the assumptions used in the calculations.
(2) The double-line column, containing ratio values equal to one, represents a comparison with the base case value. Shaded
boxes indicate calculated radionuclide soil concentrations that do not differ from the base case concentration by more than
0.1%, i.e., three decimal places.
(3) The following parameter values were assumed for the base case, generic site analysis:
*Contaminated Zone Area = 10,000 m2;
*Contaminated Zone Thickness = 2 m;
* Infiltration Rate = 0.5 m/yr;
*Kd = radionuclide specific; and
*Uncontaminated, unsaturated Zone Thickness = 2 m.
Review Draft - 9/26/94
3-59
Do Not Cite Or Quote
-------
Table 3-17. RESRAD Parameter Sensitivity Analysis: Infiltration Rate
Nuclide
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
Cl-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241 +D
Pu-242
Pu-244 +D
Ra-226 +D
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
3
1
0.3
90
12
1
1
11
22
0.1
21
125
26
16
0.4
1
40
1
1
1
60
6,761
51
34
0.1
2
1
0.4
1
897
285
1
3
3
4,120
101
104
104
3,076
108
1
0.1
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the Infiltration Rate (m/yr)
0.001
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.11
39.11
1
1
1
1
1
1
8.07
1.02
1
1
1
1
1
0.99
1
1
1
0.025
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.31
9.69
1
1
1
1
1
1
6.95
1.03
1
1
1
1
1
0.99
1
1.01
1
0.1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.45
3.51
1
1
1
1
1
1
3.39
1.07
1
1
1
1
1
0.99
1
1
1
0.5
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.00
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0.61
0.65
1
1
1
1
1
1
0.59
0.79
1
1
1
0.37
0.40
1.01
0.36
1.75
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.87
0.47
1
1
1
1
1
1
0.42
0.67
1
1
1
0.28
0.25
1.02
0.27
2.01
1
Review draft - 9/26/94
3-60
Do Not Cite Or Quote
-------
Table 3-17. RESRAD Parameter Sensitivity Analysis: Infiltration Rate
Nuclide
Ra-228 +D
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Tl-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
Zn-65
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
1
4
3
137
12,752
1
2
1
4
0.5
0.3
53
1
5
5
4
6
4
1
Average Ratio =
Minimum Ratio =
Maximum Ratio =
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the Infiltration Rate (m/yr)
0.001
1
1
1
2.04
1
1
1.73
1
1
0.88
0.99
1
0.54
6.59
11.35
2.91
24.78
11.46
1
2.62
0.54
39.11
0.025
1
1
1
2.04
1
1
1.73
1
1
0.88
0.99
1
0.55
6.26
7.76
3.55
11.32
8.50
1
1.80
0.55
11.32
0.1
1
1
1
2.04
1
1
1.73
1
1
0.90
1
1
0.55
3.74
3.95
2.51
4.02
3.66
1
1.32
0.55
4.02
0.5
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.00
1
1
1
0.66
1
1
0.73
1
1
1.13
1.01
1
0.76
0.57
0.57
0.62
0.57
0.58
1
0.91
0.36
1.75
2
1
1
1
0.50
1
1
0.57
1
1
1.26
1.01
1
0.66
0.41
0.40
0.46
0.40
0.41
1
0.91
0.25
2.01
Notes:
(1) Sensitivity analyses were performed using the DOE RESRAD computer code (Version 5.19). See text for a discussion of
these analyses and the assumptions used in the calculations.
(2) The double-line column, containing ratio values equal to one, represents a comparison with the base case value. Shaded
boxes indicate calculated radionuclide soil concentrations that do not differ from the base case concentration by more than
0.1%, i.e., three decimal places.
(3) The following parameter values were assumed for the base case, generic site analysis:
*Contaminated Zone Area = 10,000 m2;
*Contaminated Zone Thickness = 2 m;
* Infiltration Rate = 0.5 m/yr;
*Kd = radionuclide specific; and
*Uncontaminated, unsaturated Zone Thickness = 2 m.
Review draft - 9/26/94
3-61
Do Not Cite Or Quote
-------
Kd Values. The results of the sensitivity analyses on Kd value are provided in Table 3-18.
The results indicate that for most radionuclides:
• the RSC will decrease by a factor of about 0.7 when the Kd value varies from
the base case to the low-end value
the RSC will increase by a factor of about 8 from the low-end (base case) to the
high-end Kd values, even though the Kds for some radionuclides range over
several orders of magnitude from the low- to high-end values.
Risk factors are only affected by Kd when contaminated groundwater contributes to the total
risk. Radionuclides dominated by external exposure, such as Cs-137, never reach the
groundwater so Kd has no affect on the cleanup concentration. Radionuclides with high Kd
values, such as Ac-227+D (Kd values range from 240 to 2,900 cm3/g), do not reach the
groundwater in the time frames being investigated.
Radionuclides that are dominated by water dependent pathways, such as U-238, are affected
by changes in Kd values. The risk factor for U-238 increases by a factor of 50 when the low-
end Kd value is substituted into the calculations, and decreases by a factor of 11 when the
high-end Kd value is substituted. For radionuclides with very low Kd values, such as H-3 and
1-129, the affect is even more pronounced.
Radionuclides that have significant ingrowth of radon isotopes during the model's 1000 year
time frame, such as Th-230 and U-232, are also affected by changes in Kd. Higher Kd values
prevent the radium isotopes from migrating deeper into the soil, allowing the concentrations
of Ra-226+D and Ra-228+D to increase to the point where indoor radon levels are the
dominant exposure pathway.
Unsaturated Zone Thickness. The results of sensitivity analyses on unsaturated zone
thickness are provided in Table 3-19. The results indicate that, on average, RSCs for most
radionuclides remain relatively constant when the unsaturated zone thickness ranges from 0 to
50 m. Radionuclide risk factor calculations are generally insensitive to wide changes in the
unsaturated zone thickness.
Review Draft - 9/26/94 3-62 Do Not Cite Or Quote
-------
Table 3-18. RESRAD Parameter Sensitivity Analysis: Distribution Coefficient (Kd)
Nuclide
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
Cl-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241 +D
Pu-242
Pu-244 +D
Ra-226 +D
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
3
1
0.3
90
12
1
1
11
22
0.1
21
125
26
16
0.4
1
40
1
1
1
60
6,761
51
34
0.1
2
1
0.4
1
897
285
1
3
3
4,120
101
104
104
3,076
108
1
0.1
Ratio of the Calculated Soil Concentration
to the Base Case Soil Concentration
as a Function of the Kd value:
Low
1
1
1
NC
0.01
1
1
1
1
1
1
1
0.09
0.42
0.40
0.18
0.02
0.07
1
1
1
0.03
1
1.21
0.21
1
1
1
1
1
1
0.08
1
0.04
1
0.02
0.01
0.01
0.01
NC
0.66
0.85
Base Case
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Mid-1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
119.01
2.59
1
1
1
1
1
1
5.22
1.07
1
1
1
1
1
0.99
1
1
1
Mid-2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
311.75
16.14
1
1
1
1
1
1
8.07
1.04
1
1
1
1
1
0.99
1
1.01
1
High
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
311.75
39.11
1
1
1
1
1
1
8.07
1.04
1
1
1
1
1
0.99
1
1
1
Radionuclide-Specific Kd Value (mi/g):
Low
240
3
3
1
1
30
5
1
40
2
93
93
93
0
0
0
0
0
240
240
240
1
240
0
0
16
0
44
110
60
60
0
110
5
240
11
11
11
11
11
11
57
Base Case
240
90
90
1,900
1,900
30
5
40
500
2
4,000
4,000
4,000
60
60
270
270
270
240
240
240
170
240
0
1
16
50
44
110
150
150
5
110
270
240
550
550
550
550
550
550
500
Mid-1
1,000
150
150
9,000
9,000
130
14
320
5,700
7
6,000
6,000
6,000
780
780
1,100
1,100
1,100
1,000
1,000
1,000
410
1,000
15
3
71
170
190
480
530
530
40
480
8,300
1,000
1,500
1,500
1,500
1,500
1,500
1,500
2,100
Mid-2
2,900
15,000
15,000
110,000
110,000
370
39
800
20,000
19
18,000
18,000
18,000
1,300
1,300
4,600
4,600
4,600
2,900
2,900
2,900
800
2,900
42
25
200
750
540
1,300
1,100
1,100
1,200
1,300
22,000
2,900
5,100
5,100
5,100
5,100
5,100
5,100
9,100
High
2,900
33,000
33,000
450,000
450,000
370
39
17,000
56,000
19
52,000
52,000
52,000
14,000
14,000
145,000
145,000
145,000
2,900
2,900
2,900
6,000
2,900
42
370
200
77,000
540
1,300
4,700
4,700
2,600
1,300
59,000
2,900
300,000
300,000
300,000
300,000
300,000
300,000
530,000
Review Draft - 9/26/94
3-63
Do Not Cite Or Quote
-------
Table 3-18. RESRAD Parameter Sensitivity Analysis: Distribution Coefficient (Kd)
Nuclide
Ra-228 +D
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Tl-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
Zn-65
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
1
4
3
137
12,752
1
2
1
4
0.5
0.3
53
1
5
5
4
6
4
1
Average Ratio=
Minimum Ratio=
Maximum Ratio=
Ratio of the Calculated Soil Concentration
to the Base Case Soil Concentration
as a Function of the Kd value:
Low
1.01
1
1
1
1
0.05
0.77
1
1.02
1.47
1.05
1
0.04
0.02
0.02
0.02
0.02
NC
0.73
0.66
0.01
1.47
Base Case
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Mid-1
1
1
1
2.04
1
1
1.73
1
1
0.91
1
1
0.55
6.62
8.06
3.90
11.32
8.78
1
3.60
0.55
119
Mid-2
1
1
1
2.04
1
1
1.73
1
1
0.88
0.99
1
0.54
6.91
11.85
3.14
24.78
11.46
1
7.35
0.54
312
High
1
1
1
2.04
1
1
1.73
1
1
0.88
0.99
1
0.54
6.47
11.18
2.85
24.78
11.45
1
7.70
0.54
312
Radionuclide-Specific Kd Value (mi/g):
Low
57
5
45
240
240
0
0
207
207
207
207
20
0
0
0
0
0
0
0
62
0
240
Base Case
500
55
45
240
240
15
0
3,200
3,200
3,200
3,200
20
15
15
15
15
15
15
200
623
0
4,000
Mid-1
2,100
900
480
1,000
1,000
65
1
4,500
4,500
4,500
4,500
89
220
220
220
220
220
220
1,500
1,674
1
9,000
Mid-2
9,100
66,000
1,300
2,900
2,900
150
1
89,000
89,000
89,000
89,000
250
1,600
1,600
1,600
1,600
1,600
1,600
2,400
14,421
1
110,000
High
530,000
87,000
1,300
2,900
2,900
32,000
340
13,000,000
13,000,000
13,000,000
13,000,000
250
400,000
400,000
400,000
400,000
400,000
400,000
100,000
972,463
19
13,000,000
Notes:
(1) Sensitivity analyses were performed using the DOE RESRAD computer code (Version 5.19). See text for a discussion of these analyses
and the assumptions used in the calculations.
(2) The double-line column, containing ratio values equal to one, represents a comparison with the base case value. Shaded boxes indicate
calculated radionuclide soil concentrations that do not differ from the base case concentration by more than 0.1%, i.e., three decimal
places.
(3) The following parameter values were assumed for the base case, generic site analysis:
*Contaminated Zone Area = 10,000 m2;
*Contaminated Zone Thickness = 2 m;
* Infiltration Rate = 0.5 m/yr;
*Kd = radionuclide specific; and
*Uncontaminated, unsaturated Zone Thickness = 2 m.
NC = Not calculated. RESRAD program error encountered during calculation.
Review Draft - 9/26/94
3-64
Do Not Cite Or Quote
-------
Table 3-19. RESRAD Parameter Sensitivity Analysis: Unsaturated Zone Thickness
Nuclide
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-241
Am-243 +D
Bi-207
C-14
Cd-109
Ce-144+D
Cl-36
Cm-243
Cm-244
Cm-248
Co-57
Co-60
Cs-134
Cs-135
Cs-137+D
Eu-152
Eu-154
Eu-155
Fe-55
Gd-153
H-3
1-129
K-40
Mn-54
Na-22
Nb-94
Ni-59
Ni-63
Np-237 +D
Pa-231
Pb-210+D
Pm-147
Pu-238
Pu-239
Pu-240
Pu-241 +D
Pu-242
Pu-244 +D
Ra-226 +D
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
3
1
0.3
90
12
1
1
11
22
0.1
21
125
26
16
0.4
1
40
1
1
1
60
6,761
51
34
0.1
2
1
0.4
1
897
285
1
3
3
4,120
101
104
104
3,076
108
1
0.1
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the UnContaminated, Unsaturated Zone Thickness (m):
0
1
1
1
1
1.05
1
1
1
1
1
1
1
0.98
1
1
1
1
1
1
1
1
1
1
1.68
0.99
0.97
1
1
1
1
1
0.96
0.67
1
1
1
0.42
0.43
0.96
0.41
1.11
1
0.5
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.68
0.99
1
1
1
1
1
1
0.97
0.83
1
1
1
0.43
0.46
1
0.43
1.23
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0.90
1
1
1
1
1
1
1
0.98
0.88
1
1
1
0.53
0.57
1
0.51
1.33
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
10
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.36
1.01
1
1
1
1
1
1
1.06
1.23
1
1
1
1
1
1
1
1
1
50
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1.68
1.02
1
1
1
1
1
1
1.08
1.23
1
1
1
1
1
1
1
1
1
Review Draft - 9/26/94
3-65
Do Not Cite Or Quote
-------
Table 3-19. RESRAD Parameter Sensitivity Analysis: Unsaturated Zone Thickness
Nuclide
Ra-228 +D
Ru-106+D
Sb-125+D
Sm-147
Sm-151
Sr-90 +D
Tc-99
Th-228 +D
Th-229 +D
Th-230
Th-232
Tl-204
U-232
U-233
U-234
U-235 +D
U-236
U-238 +D
Zn-65
Base Case, Generic
Site Radionuclide Soil
Concentration (pCi/g)
at a 1 x 10"1 Risk Level
1
4
3
137
12,752
1
2
1
4
0.5
0.3
53
1
5
5
4
6
4
1
Average Ratio=
Minimum Ratio=
Maximum Ratio=
Ratio of the Calculated Soil Concentration to the Base Case Soil Concentration
as a Function of the UnContaminated, Unsaturated Zone Thickness (m):
0
1
1
1
0.87
0.97
1
0.86
1
1
0.99
1
1
0.51
0.99
0.99
0.91
0.99
0.97
1
0.96
0.41
1.68
0.5
1
1
1
0.91
1
1
0.89
1
1
0.99
1
1
0.59
0.99
0.99
0.94
0.99
0.98
1
0.97
0.43
1.68
1
1
1
1
0.94
1
1
0.93
1
1
1
1
1
0.71
1
0.99
0.96
0.99
0.99
1
0.97
0.51
1.33
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
10
1
1
1
2.04
1
1
1.73
1
1
1
1
1
0.59
1.02
1.02
1.18
1.02
1.04
1
1.04
0.59
2.04
50
1
1
1
1.04
1
1
1.73
1
1
1
1
1
0.59
1.75
1.76
2.12
1.77
1.81
1
1.11
0.59
2.12
Notes:
(1) Sensitivity analyses were performed using the DOE RESRAD computer code (Version 5.19). See text for a discussion of
these analyses and the assumptions used in the calculations.
(2) The double-line column, containing ratio values equal to one, represents a comparison with the base case value. Shaded
boxes indicate calculated radionuclide soil concentrations that do not differ from the base case concentration by more than
0.1%, i.e., three decimal places.
(3) The following parameter values were assumed for the base case, generic site analysis:
*Contaminated Zone Area = 10,000 m2;
*Contaminated Zone Thickness = 2 m;
* Infiltration Rate = 0.5 m/yr;
*Kd = radionuclide specific; and
*Uncontaminated, Unsaturated Zone Thickness = 2 m.
Review Draft - 9/26/94
3-66
Do Not Cite Or Quote
-------
Results by Radionuclide Type. The results of the RESRAD analyses (see Tables 3-15
through 3-19) suggest that the sensitivity of any given radionuclide to changes in site-specific
parameter values can be predicted with a fair degree of specificity based on its dominant
exposure pathway. The results also show that radionuclides with similar or identical
dominant exposure pathways will respond in similar ways when certain model parameters are
modified. In general, these findings suggest that each radionuclide can be sorted into one of
four different pathway-dependent categories with common sensitivity characteristics. These
categories are: (1) external exposure dependent, (2) water pathway independent, (3) water
pathway dependent, and (4) radon pathway dependent. Table 3-20 presents distributions of
radionuclides by dominant pathways. The sensitivity characteristics of the radionuclides in
each category are described below. Graphs of the results for each individual radionuclide are
presented in Appendix H.
External Exposure Pathway Dependent Radionuclides With respect to parameter
sensitivity, radionuclides that emit photon radiation of significant energy and abundance, such
as Cs-137+D (see Figure 3-5), may be classified as external exposure pathway dependent.
The largest percentage (approximately 45%) of all radionuclides evaluated fall into this group.
For external exposure pathway dependent radionuclides:
• the RSC will increase by a factor of approximately 2 when the area of the
contaminated zone decreases by a factor of 100 from the base case and
decrease slightly by a factor of 0.98 when the area increases by a factor of
1,000 from the base case
the RSC will increase by a factor of approximately 5 when the contaminated
zone thickness decreases by a factor of 100 from the base case and remain
constant when the thickness equals or exceeds one meter
• the RSC will remain constant when the infiltration rate is increased or
decreased from the base case
• the RSC will remain constant for low-end, mid-range, and high-end distribution
coefficients (Kd)
the RSC will remain constant when the unsaturated zone thickness is increased
or decreased from the base case
Review Draft - 9/26/94 3-67 Do Not Cite Or Quote
-------
Table 3-20. Distribution of Radionuclides by Dominant Pathway
External
Exposure
Ac-227+D
Ag-108m+D
Ag-llOm+D
Am-243+D
Bi-207
Ce-144+D
Cm-243
Co-57
Co-60
Cs-134
Cs-137+D
Eu-152
Eu-154
Eu-155
Gd-153
Mn-54
Na-22
Nb-94
Pa-231
Pu-244+D
Ra-228+D
Ru-106+D
Sb-125+D
Th-228+D
Th-229+D
Th-232
U-232
27
Water Pathway
Independent
Am-2411
C-141
Cd-1091
Cl-362
Cm-2441
Cm-2481
Cs-1352
Fe-552
K-402
Ni-593
Ni-633
Pb-210+D1
Pm-1471
Pu-2381
Pu-2391
Pu-2401
Pu-2411
Pu-2421
Sm-1511
Sr-90+D1
Tl-2041
Zn-652
22
Water Pathway
Dependent
H-3
1-129
Np-237+D
Sm-147
Tc-99
U-233
U-234
U-235+D
U-236
U-238+D
10
Radon
Inhalation
Ra-226+D
Th-230
2
Plant ingestion
Meat ingestion
Milk ingestion
Review Draft - 9/26/94
3-68
Do Not Cite Or Quote
-------
Figure 3-5. Cs-137
RESRAD Parameter Sensitivity Analyse:
Performed using the DOE RESRAD computer code (Versior
assuming generic site conditions. Parameters varied individi
Sensitivity Parameter Lifetime Risk RSC (pCi/g) Time of Max.
Analysis Value per pCi/g at 10-4 Risk Risk(yr)
#1 1E+02 3.11E-05 3.2 0
Contaminated 1E+03 5.81E-05 1.7 0
Zone Area 1E+04 7.30E-05 1.4 0
(m2) 1E+05 8.60E-05 1.2 0
1E+06 8.60E-05 1.2 0
1E+07 8.60E-05 1.2 0
#2 0.02 1.26E-05 7.9 0
Contaminated 0.1 4.22E-05 2.4 0
Zone 0.2 5.62E-05 1.8 0
Thickness 1 7.30E-05 1.4 0
(m) 2 7.30E-05 1.4 0
3 7.30E-05 1.4 0
#3 0.001 7.30E-05 1.4 0
Infiltration 0.025 7.30E-05 1.4 0
Rate 0.100 7.30E-05 1.4 0
(m/yr) 0.500 7.30E-05 1.4 0
1 7.30E-05 1.4 0
1.5 7.30E-05 1.4 0
2 7.30E-05 1.4 0
#4 0 9.86E-04 0.1 1
Distribution 270 7.30E-05 1.4 0
Coefficient (Kd) 1,100 7.30E-05 1.4 0
(ml/g) 4,600 7.30E-05 1.4 0
145,000 7.30E-05 1.4 0
#5 0 7.30E-05 1.4 0
Uncontaminated 1 7.30E-05 1.4 0
Unsat. Zone 1 7.30E-05 1.4 0
Thickness 2 7.30E-05 1.4 0
(m) 10 7.30E-05 1.4 0
50 7.30E-05 1.4 0
Note: See text for a detailed discussion of these analyses.
Parameter * Agricultural Land Use Exposure Scenario
values assumed * Area of Contaminated Zone = 10,000 rn
for base case * Thickness of Contaminated Zone = 2 m
analysis: * Infiltration Rate = 0.5 m/yr
* Thickness of Unsaturated Zone = 2 m
* Well Depth Below Water Table = 3 m
*RSC = Radionuclide-specific soil concentration (in pCi
corresponding to a lifetime risk level of 10-4.
Analysis 1: Contaminated Zone
Area
to
o: i
"f
ra
5
O n 1
Q.U. I
O
OL
•^--^
100 1000 10000 100000 1E+06 1E+07
Area of Contaminated Zone (m 2)
Analysis 3:
RSC(pCi/g) at 10-4 Risk
0
I -
Infiltration Rate
0.0 0.5 1.0 1.5 2.0
Infiltration Rate (m/yr)
Analysis 2: Contaminated Zone
Thickness
1
"f
° 1
ra
5
O
^ 0 01 -
0123
Thickness of Contaminated Zone (m)
Analysis 4: Kd Value
to
I 1
TO
5
o n * _
o
a:
-Q •— • •
^/_
1E-01 1E+01 1E+03 1E+05 1E+07
Kd Value (ml/g)
Analysis 5: Thickness of Uncontaminated/Unsaturated Zone
° m
+
c
1
t
t
u
Q
? » 1
jo: n ! .
i
- 0 5 10 15 20 25 30 35 40 45 50
Uncontaminated/Unsaturated Zone Thickness (m)
-------
The results show photon-emitting radionuclides are generally unaffected by site-specific
parameters, which directly impact the migration of radionuclides to groundwater, such as the
infiltration rate, Kd value, and the thickness of the unsaturated zone—these are only slightly
affected by the area of the contaminated zone. In general, the dose rates and risks posed by
this group of radionuclides are maximized at time zero (t = 0).
Water Pathway Independent Radionuclides. Water pathway independent radionuclides are
characterized as radionuclides with relatively high distribution coefficients (Kd values) which
limit their rate of migration to groundwater. As a group, these radionuclides emit
predominantly alpha or beta radiation with weak or no photon emissions. The sensitivity of
plutonium-239 (see Figure 3-6) is typical of the response exhibited by many of the
radionuclides in this category. On average for these radionuclides:
• the RSC will increase by a factor of approximately 20 when the area of the
contaminated zone decreases by a factor of 100 from the base case, and
decrease by a factor of 0.7 when the area increases by a factor of 1,000 from
the base case
the RSC will increase by a factor of approximately 25 when the contaminated
zone thickness decreases by a factor of 100 from the base case and remain
constant when the thickness equals or exceeds one meter
• the RSC will remain constant when the infiltration rate is increased or
decreased relative to the base case
• the RSC will remain constant for low-end, mid-range, and high-end Kd values
• the RSC will decrease slightly by a factor of approximately 0.9 when there is
no unsaturated zone, and remain constant when the unsaturated zone thickness
is increased
These results show that water pathway independent radionuclides are generally more sensitive
than external exposure pathway dependent radionuclides to changes in site-specific parameter
values.
Review Draft - 9/26/94 3-70 Do Not Cite Or Quote
-------
Figure 3-6. Pu-239
RESRAD Parameter Sensitivity Analyse:
Performed using the DOE RESRAD computer code (Versior
assuming generic site conditions. Parameters varied indivich
Sensitivity
Analysis
#1
Contaminated
Zone Area
(m2)
#2
Contaminated
Zone
Thickness
(m)
#3
Infiltration
Rate
(m/yr)
#4
Distribution
Coefficient (Kd)
(ml/g)
#5
Uncontaminated
Unsat. Zone
Thickness
(m)
Note: See text for
Parameter
values assumed
for base case
analysis:
Parameter Lifetime Risk RSC (pCi/g) Time of Max.
Value per pCi/g at 10-4 Risk
1E+02 3.23E-07
1E+03 9.13E-07
1E+04 9.58E-07
1E+05 9.92E-07
1E+06 9.94E-07
1E+07 9.95E-07
0.02 7.08E-08
0.1 3.54E-07
0.2 5.59E-07
1 9.58E-07
2 9.58E-07
3 9.58E-07
0.001 9.58E-07
0.025 9.58E-07
0.100 9.58E-07
0.500 9.58E-07
1 2.58E-06
1.5 3.46E-06
2 5.04E-06
11 8.20E-05
550 9.58E-07
1,500 9.58E-07
5,100 9.58E-07
300,000 9.58E-07
0 2.31 E-06
1 2.20E-06
1 1.82E-06
2 9.58E-07
10 9.58E-07
50 9.58E-07
309.6
109.5
104.4
100.8
100.6
100.5
1411.6
282.6
178.9
104.4
104.4
104.4
104.4
104.4
104.4
104.4
38.7
28.9
19.8
1.2
104.4
104.4
104.4
104.4
43.4
45.4
54.8
104.4
104.4
104.4
Risk(yr)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1,000
1,000
766
36
0
0
0
0
426
766
1,000
0
0
0
a detailed discussion of these analyses.
* Agricultural Land Use Exposure Scenario
•Area of Contaminated Zone = 10,000 rn
* Thickness of Contaminated Zone = 2 m
* Infiltration Rate = 0.5 m/yr
* Kd = 550
* Thickness of Unsaturated Zone = 2 m
* Well Depth Below Water Table = 3 m
*RSC = Radionuclide-specific soil concentration (in pCi
corresponding to a lifetime risk level of 10-4.
Analysis 1: Contaminated Zone
Area
.2 Ik^
0
*- 10
re
5
O
O~ 0 1 -
UJ
OL
0.01 -\ 1 1 1 1 1
100 1000 10000 100000 1E+06 1E+07
Area of Contaminated Zone (m 2)
Analysis 3: Infiltration Rate
1000
^
2 1001
o
^ 10 -
re
"S
o
g 0.1
" "^^»^_-
^ — *- — .
0.0 0.5 1.0 1.5 2.0
Infiltration Rate (m/yr)
t
0
re
J
O
£
O
UJ
An
x. 10000
.2
^ 1000
? 100
5. 10
-51
0 0.1
UJ
^ 0.01
alysis 2: Contaminated Zone
Thickness
I
-^ • • •
0123
Thickness of Contaminated Zone (m)
Analysis 4: Kd Value
to
0
H 10 -
re
b
^/
1 100 10,000 1,000,000
Kd Value (ml/g)
Analysis 5: Thickness of Uncontaminated/Unsaturated Zone
-^ m
« IU
0 5 10 15 20 25 30 35 40 45 50
Uncontaminated/Unsaturated Zone Thickness (m)
-------
Figure 3-7. U-238+D
RESRAD Parameter Sensitivity Analyse:
Performed using the DOE RESRAD computer code (Versior
assuming generic site conditions. Parameters varied individi
Sensitivity Parameter Lifetime Risk RSC (pCi/g) Time of Max.
Analysis Value per pCi/g at 10-4 Risk Risk(yr)
#1 1E+02 3.30E-06 30.3 39
Contaminated 1E+03 1.02E-05 9.8 41
Zone Area 1E+04 2.84E-05 3.5 49
(m2) 1E+05 7.71 E-05 1.3 75
1E+06 1.24E-04 0.8 107
1E+07 1.55E-04 0.6 107
#2 0.02 2.12E-06 47.1 49
Contaminated 0.1 9.91E-06 10.1 49
Zone 0.2 1.58E-05 6.3 49
Thickness 1 2.60E-05 3.8 49
(m) 2 2.84E-05 3.5 49
3 2.92E-05 3.4 49
#3 0.001 2.47E-06 40.4 0
Infiltration 0.025 3.33E-06 30.0 762
Rate 0.100 7.75E-06 12.9 200
(m/yr) 0.500 2.84E-05 3.5 49
1 4.92E-05 2.0 31
1.5 6.86E-05 1.5 24
2 8.57E-05 1.2 21
#4 0 NC NC NC
Distribution 15 2.84E-05 3.5 49
Coefficient (Kd) 220 3.23E-06 31.0 716
(ml/g) 1,600 2.47E-06 40.4 0
400,000 2.48E-06 40.4 1,000
#5 0 2.91 E-05 3.4 12
Uncontaminated 1 2.89E-05 3.5 21
Unsat. Zone 1 2.87E-05 3.5 31
Thickness 2 2.84E-05 3.5 49
(m) 10 2.72E-05 3.7 200
50 1.56E-05 6.4 1,000
Note: See text for a detailed discussion of these analyses.
Parameter * Agricultural Land Use Exposure Scenario
values assumed * Area of Contaminated Zone = 10,000 rn
for base case * Thickness of Contaminated Zone = 2 m
analysis: * Infiltration Rate = 0.5 m/yr
* Thickness of Unsaturated Zone = 2 m
* Well Depth Below Water Table = 3 m
*RSC = Radionuclide-specific soil concentration (in pCi
corresponding to a lifetime risk level of 10-4.
Analysis 1: Contaminated Zone
Area
£ i
OL h
•* 10
0
^ 1 -
O
°-01
O
tn
OL
•^
^^
100 1000 10000 100000 1E+06 1E+07
Area of Contaminated Zone (m 2)
RSC (pCi/g) at 10-4 Risk
0 _^
Analysis 3: Infiltration Rate
00
10 \
^^^^_
0.0 0.5 1.0 1.5 2.0
Infiltration Rate (m/yr)
Analysis 2: Contaminated Zone
Thickness
S '
| 10
O
o
0 01
\
V
• •
\ \ 1
0123
Thickness of Contaminated Zone (m)
Analysis 4: Kd Value
to
"t 10 -
0
O
Q.
O
tn
OL
7
1E-02 1E+00 1E+02 1E+04 1E+06
Kd Value (ml/g)
Analysis 5: Thickness of Uncontaminated/Unsaturated Zone
"f
° !
TO
-P>"i/i n 1
o o£
Q.
& 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Uncontaminated/Unsaturated Zone Thickness (m)
-------
Water Pathway Dependent Radionuclides. Water pathway dependent radionuclides are
radionuclides with relatively low distribution coefficients. Uranium-238+D (see Figure 3-7)
is typical of many of the radionuclides in this group, and H-3 (see Figure 3-8) is a special case
member of this group. On average for water pathway dependent radionuclides:
• the RSC will increase by a factor of approximately 10 when the area of the
contaminated zone decreases by a factor of 100 from the base case, and
decrease by a factor of approximately 0.2 when the area increases by a factor of
1,000 from the base case
the RSC will increase by a factor of approximately 20 when the contaminated
zone thickness decreases by a factor of 100 from the base case, and decrease
slightly by a factor of 0.95 when the thickness increases by a factor of 3 from
the base case
• the RSC will increase by a factor of approximately 11 when the infiltration rate
decreases by a factor of 200, and decrease by a factor of 0.6 when the
infiltration factor increases by a factor of 4 from the base case
• the RSC will increase by a factor of approximately 42 from the base case to the
high-end Kd values, and decrease by a factor of 0.4 from the base case to the
low-end Kd values
• the RSC will remain constant when there is no unsaturated zone and increase
by a factor of approximately 2 when the unsaturated zone thickness increases
by a factor of 25 from the base case.
In general, water pathway dependent radionuclides are significantly affected by site-specific
characteristics. Site characteristics that delay the transfer of radionuclides to groundwater
(e.g., a thick contaminated zone, a thick unsaturated zone, large Kd values, and low infiltration
rates) result in higher soil cleanup concentrations.
Conversely, site characteristics that enhance the transport of radionuclides to groundwater
have the opposite effect. H-3 is very sensitive to changes in assumptions regarding the
thickness of the contaminated zone.
Review Draft - 9/26/94 3-73 Do Not Cite Or Quote
-------
Figure 3-8. H-3
RESRAD Parameter Sensitivity Analyse:
Performed using the DOE RESRAD computer code (Versior
assuming generic site conditions. Parameters varied indivich
Sensitivity
Analysis
#1
Contaminated
Zone Area
(m2)
#2
Contaminated
Zone
Thickness
(m)
#3
Infiltration
Rate
(m/yr)
#4
Distribution
Coefficient (Kd)
(ml/g)
#5
Uncontaminated
Unsat. Zone
Thickness
(m)
Note: See text for
Parameter
values assumed
for base case
analysis:
Parameter Lifetime Risk RSC (pCi/g) Time of Max.
Value per pCi/g at 10-4 Risk
1E+02 2.68E-07
1E+03 1.11E-06
1E+04 2.98E-06
1E+05 7.43E-06
1E+06 1.07E-05
1E+07 1.10E-05
0.02 4.56E-08
0.1 2.28E-07
0.2 4.38E-07
1 1.78E-06
2 2.98E-06
3 3.30E-06
0.001 2.68E-06
0.025 2.28E-06
0.100 2.05E-06
0.500 2.98E-06
1 4.86E-06
1.5 1.59E-06
2 1.56E-06
0.04 2.47E-06
0 2.98E-06
15 2.50E-08
42 9.56E-09
42 9.56E-09
0 1.78E-06
1 1.78E-06
1 3.30E-06
2 2.98E-06
10 2.19E-06
50 1.78E-06
373
90
34
13
9
9
2,191
438
228
56
34
30
37
44
49
34
21
63
64
40
34
3,994
10,461
10,461
56
56
30
34
46
56
Risk(yr)
1
0
1
1
2
2
0
0
0
0
1
1
0
0
0
1
0
0
0
1
1
0
0
0
0
0
0
1
3
0
a detailed discussion of these analyses.
* Agricultural Land Use Exposure Scenario
•Area of Contaminated Zone = 10,000 rn
* Thickness of Contaminated Zone = 2 m
* Infiltration Rate = 0.5 m/yr
*Kd= 0
* Thickness of Unsaturated Zone = 2 m
* Well Depth Below Water Table = 3 m
*RSC = Radionuclide-specific soil concentration (in pCi
corresponding to a lifetime risk level of 10-4.
Analysis 1: Contaminated Zone
Area
^ 1000 ^N>"B^
15
5 n
O
cT 01-
V)
OL
100 1000 10000 10000 1E+06 1E+07
Area of Contaminated Zone (m 2)
Analysis 3: Infiltration Rate
100 0
o
o
0.0 0.5 1.0 1.5 2.0
Infiltration Rate (m/yr)
Analysis 2: Contaminated Zone
Thickness
~ i
° 100.0 -
o.
-------
Radon Inhalation Pathway Dependent Radionuclides Radon (Rn-222) inhalation is the
dominant exposure pathway for Ra-226+D (see Figure 3-9) and Th-230 (Figure 3-10). The
sensitivity analyses show that, for these radionuclides, the site specific risk factors are very
sensitive to changes in the assumed thickness of the contaminated zone. These analyses show
that the contaminated zone must be at least 2 meters thick before water independent radon
inhalation becomes a significant pathway. If the contaminated zone thickness is decreased,
there is less radon produced underneath the house than is available to migrate into the house.
Once the contaminated zone exceeds 2 meters, the radon migrates through the soil into the
house before it decays, so increasing the thickness of the contaminated zone produces an
increase in indoor radon.
3.1.4 Uncertainty Analysis
A preliminary quantitative analysis is performed to determine the degree of uncertainty in the
derived generic risk factors for a given exposure scenario. Here, the analysis is performed
using the modified RAGS/HHEM Part B models and Monte Carlo techniques.
The uncertainty analysis is performed using artificially constructed parameter distributions to
describe the generic test site. Uncertainty analyses are most appropriately applied to real
sites, where parameter distributions can be determined for site-specific characteristics (i.e.,
area of contamination, thickness of the contaminated zone, depth to aquifer, Kd, hydraulic
conductivity, etc.). For this reason the quantitative uncertainty analysis is used here only as a
proof of concept—to demonstrate that the technique can be applied to a real site.
The results of the uncertainty analysis are included in Appendix I. Also included in the
appendix is a list of the input parameter distributions used in the analysis.
3.2 GENERIC TEST SITE POPULATION IMPACTS
In addition to posing a health risk to individuals in the vicinity of a contaminated site,
contamination poses a risk to the aggregate population living on or in the vicinity of a site.
This section presents the cumulative population impacts at the generic site using the models,
scenarios, and assumptions described in Section 2.2. It is designed to demonstrate the
advantages and limitations of the models and the appropriateness of the assumption for use in
evaluating the cumulative population impacts at the reference sites. It also provides insight
into the limiting pathways for each radionuclide.
Review Draft - 9/26/94 3-75 Do Not Cite Or Quote
-------
Figure 3-9. Ra-226+D
RESRAD Parameter Sensitivity Analyse:
Performed using the DOE RESRAD computer code (Versior
assuming generic site conditions. Parameters varied indivich
Sensitivity Parameter Lifetime Risk RSC (pCi/g) Time of Max.
Analysis Value per pCi/g at 10-4 Risk Risk(yr)
#1 1E+02 7.30E-04 0.14 0
Contaminated 1E+03 1.09E-03 0.09 8
Zone Area 1E+04 1.11E-03 0.09 11
(m2) 1E+05 1.15E-03 0.09 14
1E+06 1.23E-03 0.08 11
1E+07 1.50E-03 0.07 5
#2 0.02 3.33E-05 3.01 0
Contaminated 0.1 1.19E-04 0.84 0
Zone 0.2 1.68E-04 0.59 0
Thickness 1 2.43E-04 0.41 67
(m) 2 1.11E-03 0.09 11
3 1.15E-03 0.09 19
#3 0.001 1.12E-03 0.09 27
Infiltration 0.025 1.12E-03 0.09 26
Rate 0.100 1.11E-03 0.09 23
(m/yr) 0.500 1.11E-03 0.09 11
1 1.11E-03 0.09 1
1.5 1.11E-03 0.09 0
2 1.11E-03 0.09 0
#4 57 1.31E-03 0.08 57
Distribution 500 1.11E-03 0.09 11
Coefficient (Kd) 2,100 1.11E-03 0.09 22
(ml/g) 9,100 1.12E-03 0.09 26
530,000 1.12E-03 0.09 26
#5 0 1.11E-03 0.09 14
Uncontaminated 1 1.11E-03 0.09 11
Unsat. Zone 1 1.11E-03 0.09 11
Thickness 2 1.11E-03 0.09 11
(m) 10 1.11E-03 0.09 11
50 1.11E-03 0.09 11
Note: See text for a detailed discussion of these analyses.
Parameter * Agricultural Land Use Exposure Scenario
values assumed * Area of Contaminated Zone = 10,000 rn
for base case * Thickness of Contaminated Zone = 2 m
analysis: * Infiltration Rate = 0.5 m/yr
* Thickness of Unsaturated Zone = 2 m
* Well Depth Below Water Table = 3 m
*RSC = Radionuclide-specific soil concentration (in pCi
corresponding to a lifetime risk level of 10-4.
Analysis 1: Contaminated Zone
Area
J.OO
to
'OL
"f
0
O
£
O
tn
OL
100 1000 10000 100000 1E+06 1E+07
Area of Contaminated Zone (m 2)
Analysis 3: Infiltration Rate
1 00
^
to
'OL
"f
o
O
o.
O
£
0.0 0.5 1.0 1.5 2.0
Infiltration Rate (m/yr)
An
^ 10.00
tn
'OL
"f
? 1.00
'm
5
O 0.10
o.
O
(/>
* 0.01
alysis 2: Contaminated Zone
Thickness
\
^^^^
! ! 1
0123
Thickness of Contaminated Zone (m)
Analysis 4: Kd Value
^
tn
'OL
t
0
" 0.10-
•51
o
^
o
tn
OL
1
100 10,000 1,000,000
Kd Value (ml/g)
Analysis 5: Thickness of Uncontaminated/Unsaturated Zone
?
° 1 00
ra
-Pin n 1n
o a:
^
K 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Uncontaminated/Unsaturated Zone Thickness (m)
-------
Figure 3-10. Th-230
RESRAD Parameter Sensitivity Analyse:
Performed using the DOE RESRAD computer code (Versior
assuming generic site conditions. Parameters varied indivich
Sensitivity Parameter Lifetime Risk RSC (pCi/g) Time of Max.
Analysis Value per pCi/g at 10-4 Risk Risk(yr)
#1 1E+02 1.32E-04 0.8 681
Contaminated 1E+03 2.05E-04 0.5 691
Zone Area 1E+04 2. 11 E-04 0.5 694
(m2) 1E+05 2.19E-04 0.5 701
1E+06 2.37E-04 0.4 709
1E+07 2.93E-04 0.3 731
#2 0.02 4.07E-08 2,458.8 0
Contaminated 0.1 1.27E-06 78.6 32
Zone 0.2 4.32E-06 23.1 86
Thickness 1 4.04E-05 2.5 629
(m) 2 2. 11 E-04 0.5 694
3 3.55E-04 0.3 1,000
#3 0.001 2.41E-04 0.4 717
Infiltration 0.025 2.39E-04 0.4 716
Rate 0.100 2.34E-04 0.4 712
(m/yr) 0.500 2. 11 E-04 0.5 694
1 1.86E-04 0.5 677
1.5 1.68E-04 0.6 664
2 1.53E-04 0.7 652
#4 207 1.44E-04 0.7 467
Distribution 3,200 2. 11 E-04 0.5 694
Coefficient (Kd) 4,500 2.31E-04 0.4 712
(ml/g) 89,000 2.39E-04 0.4 716
1.30E+07 2.41E-04 0.4 716
#5 0 2.13E-04 0.5 697
Uncontaminated 1 2.13E-04 0.5 701
Unsat. Zone 1 2. 11 E-04 0.5 696
Thickness 2 2. 11 E-04 0.5 694
(m) 10 2. 11 E-04 0.5 694
50 2. 11 E-04 0.5 694
Note: See text for a detailed discussion of these analyses.
Parameter * Agricultural Land Use Exposure Scenario
for base case * Thickness of Contaminated Zone = 2 m
analysis: * Infiltration Rate = 0.5 m/yr
* Thickness of Unsaturated Zone = 2 m
* Well Depth Below Water Table = 3 m
*RSC = Radionuclide-specific soil concentration (in pCi
corresponding to a lifetime risk level of 10-4.
Analysis 1: Contaminated Zone
Area
» lk--
0
5.0.1
O
O
tn
OL
100 1000 10000 100000 1E+06 1E+07
Area of Contaminated Zone (m 2)
Analysis 3: Infiltration Rate
Q£ T^
t
o
™ 01
-51
o
o.
O
£
0.0 0.5 1.0 1.5 2.0
Infiltration Rate (m/yr)
Analysis 2: Contaminated Zone
Thickness
& ii
"- 1000 \
^ \
° mn L
*-> y-,
™ -in "-""--"^
001 1 1 1
0123
Thickness of Contaminated Zone (m)
Analysis 4: Kd Value
"^ ^*x^
0
o
o
tn
OL
1E+00 1E+02 1E+04 1E+06 1E+08
Kd Value (ml/g)
Analysis 5: Thickness of Uncontaminated/Unsaturated Zone
o
52 °'1
Q_
OT 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Uncontaminated/Unsaturated Zone Thickness (m)
-------
The models developed to estimate population impacts indicate the time integrated cumulative
impacts are directly proportional to the total inventory of the radionuclides in the soil. For
example, the radiation dose to any one individual residing on contaminated property will not
increase if the contaminated area is increased because the radiation field, the concentration of
radionuclides in food items, and the airborne concentration of radionuclides (including indoor
radon) do not increase with the size of the contaminated area unless the contaminated area is
very small (generally less than 10,000 m2). However, the cumulative dose to a population
residing on the property will increase because the number of individuals that can reside on the
property increases. As a result, if the average radionuclide concentration at a site is reduced
in half (thereby halving the risk to an individual) but the area of contamination is doubled
(thereby doubling the number of individuals that may be exposed), the cumulative population
impact remains unchanged (note that the radionuclide inventory also remains unchanged).
In light of the above stated relationships, results of the cumulative population impacts are
most conveniently presented in terms of cancers or cancer fatalities per curie. Tables 3-21
through 3-23 present a sample of the results for selected radionuclides for the generic site.
Table 3-24 presents a more detailed listing of the key modeling assumptions.
These tables provide insight for the pathways and radionuclides that are most important in
terms of the cumulative population impacts. However, the assumptions upon which the
values are based must be kept in mind. Most importantly, the impacts for the groundwater
pathway are based on the assumption that immediately below the contaminated soil is a large
aquifer which is heavily used for domestic purposes and that the leach rate of the
contaminants is very high (as would be associated with a site with a high infiltration rate and
radionuclides with unusually low soil distribution coefficients). As demonstrated in
Chapter 4, the groundwater at most reference sites is relatively deep. Thus, for many real
sites, the potential impacts from the groundwater pathway, due to contamination from soil
leachate, are small as compared to the other pathways. This will become apparent in the
sensitivity analysis below and in the analysis of the reference sites presented in Chapter 6.
The values for direct radiation, dust inhalation, and indoor radon are based on the assumption
that the population density is 1000 persons per km2. This is equivalent to a suburban
population density, which is unrealistic for most sites (see Appendix D), at least in the near
future. Since the impacts for these pathways are directly proportional to the
Review Draft - 9/26/94 3-78 Do Not Cite Or Quote
-------
Table 3-21. Generic Population Impacts (Case 1) Expressed on a per Curie Basis (100 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 100 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
9.09E-03
l.OOE-02
O.OOE+00
5.65E-07
1.61E-07
8.37E-02
4.08E-03
O.OOE+00
1.35E-11
2.64E-03
1.91E-03
1.24E-01
1.34E-07
2.99E-04
6.46E-05
Dust
Inhalation
4.73E-08
6.79E-08
2.07E-08
1.11E-05
2.63E-04
6.04E-05
9.11E-07
4.92E-08
4.64E-11
3.04E-05
1.92E-04
1.14E-03
1.16E-05
1.08E-05
1.04E-05
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
1.01E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
9.25E-06
4.62E-03
O.OOE+00
O.OOE+00
O.OOE+00
6.40E-05
8.36E-05
1.10E-04
Crop
Ingestion
9.25E-05
3.40E-03
2.51E-05
2.57E-02
1.32E-04
9.97E-02
2.94E-04
2.82E-02
1.70E-04
5.19E-06
1.40E-03
3.42E-03
6.68E-04
7.06E-04
9.29E-04
Radon
Inhalation
5.62E-01
1.23E-02
3.35E-06
Rural With
Agricultureb
1.83E-04
3.50E-03
1.03E-03
2.57E-02
1.35E-04
1.06E-01
3.34E-04
2.82E-02
4.79E-03
3.19E-05
1.55E-03
4.67E-03
7.32E-04
7.39E-04
1.04E-03
Rural
Without
Agriculture13
9.09E-05
l.OOE-04
1.01E-03
1.17E-07
2.64E-06
6.45E-03
4.08E-05
9.25E-06
4.62E-03
2.67E-05
1.44E-04
1.25E-03
6.42E-05
8.67E-05
1.11E-04
Intermediary
With
Agriculture11
l.OOE-03
4.40E-03
1.03E-03
2.57E-02
1.58E-04
1.64E-01
7.02E-04
2.82E-02
4.79E-03
2.72E-04
2.84E-03
1.59E-02
7.34E-04
8.20E-04
1.05E-03
Intermediary
Without
Agriculture13
9.09E-04
l.OOE-03
1.01E-03
1.17E-06
2.64E-05
6.45E-02
4.08E-04
9.25E-06
4.62E-03
2.67E-04
1.44E-03
1.25E-02
6.55E-05
1.15E-04
1.18E-04
Suburban
Without
Agricultureb
9.09E-03
l.OOE-02
1.01E-03
1.17E-05
2.64E-04
6.45E-01
4.08E-03
9.30E-06
4.62E-03
2.67E-03
1.44E-02
1.25E-01
7.91E-05
3.94E-04
1.85E-04
(a) Depth of contaminated zone is equal to 2 meters. Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the base-case set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2. Intermediary scenario is based on a population density of 100 ind/km:
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-22. Generic Population Impacts (Case 1) Expressed on a per Curie Basis (1000 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 1,000 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
9.09E-03
1.05E-02
O.OOE+00
5.77E-07
4.97E-07
2.25E-01
4.08E-03
O.OOE+00
1.35E-11
2.64E-03
5.94E-02
1.03E+00
3.89E-06
2.99E-04
6.46E-05
Dust
Inhalation
4.73E-08
7.12E-08
2.07E-08
1.14E-05
8.12E-04
1.62E-04
9.11E-07
4.92E-08
4.64E-11
3.04E-05
1.48E-03
9.46E-03
1.17E-05
1.08E-05
1.04E-05
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
1.01E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
1.02E-04
4.62E-03
O.OOE+00
O.OOE+00
O.OOE+00
2.29E-03
2.99E-03
3.93E-03
Crop
Ingestion
9.25E-05
3.73E-03
2.51E-05
2.68E-02
9.98E-04
6.32E-01
2.94E-04
2.84E-02
1.70E-04
5.19E-06
1.44E-01
3.52E-02
8.00E-04
7.86E-04
1.03E-03
Radon
Inhalation
4.42E+00
1.04E+00
1.47E-03
Rural With
Agricultureb
1.83E-04
3.84E-03
1.03E-03
2.68E-02
1.01E-03
6.79E-01
3.34E-04
2.85E-02
4.79E-03
3.19E-05
1.55E-01
4.56E-02
3.11E-03
3.77E-03
4.97E-03
Rural
Without
Agriculture13
9.09E-05
1.05E-04
1.01E-03
1.19E-07
8.13E-06
4.65E-02
4.08E-05
1.02E-04
4.62E-03
2.67E-05
1.10E-02
1.04E-02
2.31E-03
2.99E-03
3.93E-03
Intermediary
With
Agriculture11
l.OOE-03
4.78E-03
1.03E-03
2.68E-02
1.08E-03
1.10E+00
7.02E-04
2.85E-02
4.79E-03
2.72E-04
2.54E-01
1.39E-01
3.24E-03
3.80E-03
4.97E-03
Intermediary
Without
Agriculture11
9.09E-04
1.05E-03
1.01E-03
1.19E-06
8.13E-05
4.65E-01
4.08E-04
1.02E-04
4.62E-03
2.67E-04
1.10E-01
1.04E-01
2.44E-03
3.02E-03
3.94E-03
Suburban
Without
Agriculture11
9.09E-03
1.05E-02
1.01E-03
1.19E-05
8.13E-04
4.65E+00
4.08E-03
1.02E-04
4.62E-03
2.67E-03
1.10E+00
1.04E+00
3.77E-03
3.30E-03
4.01E-03
(a) Depth of contaminated zone is equal to 2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the base-case set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-23. Generic Population Impacts (case 1) Expressed on a per Curie Basis (10,000 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 10,000 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
9.09E-03
1.05E-02
O.OOE+00
5.77E-07
5.08E-07
2.27E-01
4.08E-03
O.OOE+00
1.35E-11
2.64E-03
1.49E-01
2.17E+00
9.80E-06
2.99E-04
6.46E-05
Dust
Inhalation
4.73E-08
7.12E-08
2.07E-08
1.14E-05
8.31E-04
1.64E-04
9.11E-07
4.92E-08
4.64E-11
3.04E-05
3.08E-03
1.99E-02
1.18E-05
1.08E-05
1.04E-05
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
1.01E-03
O.OOE+00
3.95E-04
2.62E-04
O.OOE+00
1.02E-04
4.62E-03
O.OOE+00
O.OOE+00
O.OOE+00
2.29E-03
2.99E-03
3.93E-03
Crop
Ingestion
9.25E-05
3.73E-03
2.51E-05
2.68E-02
2.06E-03
9.35E-01
2.94E-04
2.84E-02
1.70E-04
5.19E-06
2.18E+00
2.28E-01
1.63E-03
7.86E-04
1.03E-03
Radon
Inhalation
1.03E+01
3.27E+01
6.95E-02
Rural With
Agricultureb
1.83E-04
3.84E-03
1.03E-03
2.68E-02
2.47E-03
1.04E+00
3.34E-04
2.85E-02
4.79E-03
3.19E-05
2.51E+00
2.50E-01
4.62E-03
3.77E-03
4.97E-03
Rural
Without
Agricultureb
9.09E-05
1.05E-04
1.01E-03
1.19E-07
4.03E-04
1.06E-01
4.08E-05
1.02E-04
4.62E-03
2.67E-05
3.28E-01
2.19E-02
2.99E-03
2.99E-03
3.93E-03
Intermediary
With
Agricultureb
l.OOE-03
4.78E-03
1.03E-03
2.68E-02
2.54E-03
1.99E+00
7.02E-04
2.85E-02
4.79E-03
2.72E-04
5.46E+00
4.47E-01
1.09E-02
3.80E-03
4.97E-03
Intermediary
Without
Agricultureb
9.09E-04
1.05E-03
1.01E-03
1.19E-06
4.78E-04
1.05E+00
4.08E-04
1.02E-04
4.62E-03
2.67E-04
3.28E+00
2.19E-01
9.25E-03
3.02E-03
3.94E-03
Suburban
Without
Agriculture11
9.09E-03
1.05E-02
1.01E-03
1.19E-05
1.23E-03
1.05E+01
4.08E-03
1.02E-04
4.62E-03
2.67E-03
3.28E+01
2.19E+00
7.18E-02
3.30E-03
4.01E-03
(a) Depth of contaminated zone is equal to 2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the base-case set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-24. Interim Population Model Pathways
DIRECT RADIATION
100, 1000, and 10,000 persons per km2
Federal Guidance Report No. 12 Dose Conversion
Factors
July 1994 Slope Factors
• Soil Depleted by Radioactive Decay and Leaching
Only
GROUNDWATER INGESTION
Site-Specific Infiltration Rates
• Default Retardation Factors
50% of Leachate Captured by Wells
• 1% of Captured Groundwater Consumed
Site-Specific Transit Travel Time
• Daughter Ingrowth
DUST INHALATION
50 //g/m3 Dust Loading
• Federal Guidance Report No. 11
Inhalation Dose Conversion Factors
July 1994 Slope Factors
CROP INGESTION
Crop Production Rate of 0.716 kg/m2-yr
• Contamination by Root Uptake Only
INDOOR RADON
• 1.25 pCi/L of indoor radon per pCi/g of Ra-226 in
soil, 0.5 equilibrium
236 Lung Cancers per 106 WLM
1 pCi/L of indoor radon per pCi/g of Ra-226 in Soil
Correction Factors for Thickness of Contaminated
Zone
-------
population density, the values can be adjusted up or down based on alternative assumptions
regarding population density. These adjustments were made in developing the five scenarios
presented in the right hand columns of Tables 3-21 through 3-23.
The impacts for crop ingestion are based on the assumption that the site is used heavily for
agricultural purposes and that all the crops are consumed. Since a site cannot be used heavily
for agricultural purposes and simultaneously have a high resident population density, the crop
ingestion impacts cannot be summed with the impacts from direct radiation, dust inhalation,
and indoor radon.
The impacts from the crop ingestion and groundwater pathway are not dependent on the
assumed population density at the site. For these pathways, all the radioactivity in the crops
grown at the site and 50% of the radioactivity leached to groundwater at the site is
"harvested" and is assumed to be used by the nearby populations. Unlike the other pathways,
the populations exposed from the ingestion of crops and groundwater do not need to reside
onsite. This approach to deriving population impacts is convenient because there is no need
to estimate the numbers of persons in the exposed population. This "short cut" to estimating
population impacts is especially useful when performing future use impact assessments.
However, this can only be used for contaminants where the dose-response relationship can be
assumed to be linear with no threshold.
Not all aspects of the generic site are conservative. The generic site is designed to tend
maximize the risk to an individual exposed to RME conditions, but, as applied to the time
integrated, cumulative population impacts, the generic site does not always employ the most
conservative assumptions for all pathways. For example, though the high infiltration rate and
low Kds assumed for the generic site tend to maximize the individual risks from the
groundwater pathway, they can result in an underestimate of the time integrated population
impacts. The high leach rate rapidly depletes the contaminated zone, substantively reducing
the time integrated, cumulative population impacts for the water-independent pathways (e.g.,
direct radiation). However, the use of low Kds does not substantively reduce the individual
risks from the water-independent pathways because the soil depletion rate for the
radionuclides is still relatively slow and little depletion actually occurs over the 30 year
exposure period. Further, as applied to a 1,000 year integrated population dose, the high
radionuclide leach rate does not substantively increase the time integrated cumulative
population impacts by the groundwater pathway because it simply delivers the dose quickly
without significantly changing the integrated dose. Subsequent sections demonstrate the
sensitivity of the results to these assumptions.
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3.2.1 Discussion of Radionuclides and Time Periods of Interest
The following discussion demonstrates that each radionuclide poses a substantially different
potential impact from each pathway, and the magnitude of the impacts depends on the
assumptions regarding:
1. the prevalence of the pathway (i.e., primarily assumptions regarding population
density, groundwater use, and rural residential intensity)
2. the site conditions (especially rainwater infiltration rate, depth to aquifer, and
radionuclide distribution coefficients)
3. the time period of interest over which the population impacts are integrated
Ra-226. Tables 3-21 through 3-231 reveal that Ra-226 is potentially the most hazardous
radionuclide per unit activity, primarily because of the continuous production of radon, which
can diffuse into nearby homes. On a per curie basis, radon can be many times more
hazardous than any other radionuclide. However, radon can only accumulate to high levels
indoors if relatively large volumes of contaminated soil are in close proximity to homes. RAE
90 demonstrates, beyond a distance of about five meters, the radon in soil produced by the
decaying Ra-226 generally cannot significantly influence the indoor radon levels. The radon
gas diffusion rate in soil is relatively slow and beyond five meters the radon decays to its non-
mobile progeny before reaching the home. In addition, if a home is designed to preclude
radon buildup, or if the soil properties are such that radon transport is minimized, the buildup
of indoor radon can be greatly diminished.
Even if the indoor radon impacts associated with Ra-226 in soil are mitigated, Ra-226 is still a
dominant radionuclide for many pathways. This is primarily due to the gamma radiation
emitted by its short-lived progeny, which can be assumed to always be in full equilibrium
with their parent. In addition, the ingrowth and continued presence of Pb-210 results in a
relatively significant contribution to the impacts via the crop ingestion pathway. Figure 3-11
shows the various progeny of Ra-226.
1 For the purposes of this discussion, the 1000 year integration period is used as the base case.
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Figure 3-11. U-238 Decay Series
238-.
14 b
\
234 n
24
LJ
ily
a
!
rh
d
/
/
P
234 T>
Pa
1.2m
/
/
P
234u
240,000 y
°
i
230Th
77,000
I"
226^
Ra
1,600
I"
222Rn
3.8d
I"
218 T*
Po
3.1m
1"
1
214 Pb
27m
214 ^ 210 ^
Po Po
•^ 162usec 4 140 d
214T3' / 1 210 -r>. /
Bl / la Bl / a
f\ 20m P | f\ 5.0 d P ir
/ 210Pb/ 206Pb
P 22 y P STABLE
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The impacts of Ra-226 and its progeny are almost entirely a function of population density
and the assumed relationship between Ra-226 in soil and radon and radon progeny indoors.
This topic is discussed in Section 3.2.2.
H-3 and Tc-99. On a per curie basis, H-3 and Tc-99 pose a relatively small potential impact
compared to the other radionuclides. This occurs because both radionuclides are pure, weak
beta emitters. As a result, their potential for exposure by external direct radiation is minimal.
Even if these nuclides are taken up internally, the dose per disintegration is relatively small
due the relatively weak betas, especially for H-3. Both radionuclides are also somewhat
unique because of their high mobility. Because of their chemical properties, the retardation
factor for both radionuclides approximates 1.0—which means that they don't bind to
soil—and their migration rate through the unsaturated and saturated zone is close to that of
water. Thus, groundwater is the critical pathway of exposure for these radionuclides, even at
sites with relatively deep aquifers. This is especially true for Tc-99 with its half-life of 2.1E5
years. H-3, on the other hand, has a half-life of only 12.3 years and can decay away before
reaching an aquifer—especially if the aquifer is relatively deep or if the site infiltration rate is
relatively small. For example, for some arid sites, the depth of the aquifer can be over 100
meters and the infiltration velocity could be less than 0.1 m/yr. As a result, the time for water
and H-3 to reach the aquifer is on the order of 1000 years. Over a 1000 year period, H-3 will
virtually completely decay away before reaching the aquifer. Even a 10 meter deep aquifer
with a 0.1 m/yr infiltration velocity will require about a 100 year transport time, resulting in
an approximate 300-fold reduction in the H-3 inventory before reaching the aquifer.
Co-60 and Cs-137. Co-60 and Cs-137 are strong gamma emitters and are relatively short-
lived (i.e., 5 and 30 year half-lives, respectively). As a result, the direct radiation exposure is
the dominant pathway for these radionuclides. Because of their strong gammas, they are
among the potentially more hazardous radionuclides for individual exposures. However, their
relatively short half-lives reduces their potential for long-term cumulative population impacts.
Their half-lives and high distribution coefficients result in a relatively small potential for
impacts by the other pathways, with the exception of the crop ingestion pathway for Cs-137.
(If these radionuclides are present, protection from direct radiation until they decay away is an
obvious remedy.)
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Sr-90. This radionuclide is unique in that, as a pure beta emitter, it does not pose a significant
external exposure hazard, but due to its relative mobility, its strong betas (which include its
short-lived progeny, Y-90), and the fact that Sr-90 concentrates in bone (due to a chemistry
similar to calcium), it poses a potentially substantial impact via the ingestion pathways.
However, Sr-90's contribution to the groundwater pathway in Tables 3-21 through 3-23 is due
to the conservative assumptions made regarding the groundwater pathway at the generic site.
At most sites, groundwater will likely be many meters below the contaminated zone and the
distribution coefficient for Sr-90 will be greater than that used in the analysis. As a result, the
Sr-90 will be retarded, and, due to its relatively short half-life (28 years), it will decay
substantially before reaching most groundwater resources. For example, assuming a 10 meter
deep aquifer, a soil distribution coefficient of 302, and an infiltration velocity of 1 m/yr, the
transit time from the soil surface to the aquifer for the Sr-90 is about 1500 years. As a result,
the inventory of Sr-90 will be reduced to virtually zero due to radioactive decay in transit to
the aquifer. Also, note that the transit time would exceed a 1000 year time period of interest.
Throughout this discussion and fundamental to the modeling approach employed here, is that
transport is occurring through porous media where the radionuclides can interact with the soil.
At some sites, the radionuclides could move rapidly to the aquifer. Sites with karst aquifers,
fractured media, or low pH can cause rapid transport. At these sites, the Kds can approach
zero.
Pu-239. Pu-239 is an alpha emitter with a 2.4E4 year half-life and a generally high
distribution coefficient (about 2000). As a result, its potential for direct external exposure is
minimal, and its potential risk is dominated by the inhalation and ingestion pathways. In
Tables 3-21 through 3-23, the groundwater pathway is negligible due to the long transit time,
even for the conservative assumptions employed for the groundwater pathway. For example,
at an arid site with a 10 meter deep aquifer, an infiltration velocity of 0.1 m/yr, and a Kd for
plutonium of 2000, the plutonium transit time to the aquifer would be about 1 million years.
Over this time period, the inventory of Pu-239 would decay to virtually zero before reaching
the aquifer. In addition, assuming the time period of interest is limited to 1000 years, or
2 As a rule of thumb, the retardation factor for a radionuclide can be assumed to be about a factor of 5 to 7 fold greater than the
binding coefficient. The retardation factor is an expression of the groundwater velocity relative to the velocity of the radionuclide.
Hence, if the infiltration velocity is 1 m/yr and the distribution coefficient is 30, the velocity of the radionuclide is about 0.0066
m/yr (i.e., 1 m/yr/(30 x 5)).
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even 10,000 years, the Pu-239 will not reach the aquifer within this time period. For these
types of sites, the dust inhalation and crop ingestion pathways would dominate.
U-238. In Tables 3-21 through 3-23, U-238 is assumed to be present with its short-lived, but
not its long-lived, progeny. This distinction is important because the nature and magnitude of
the potential risks associated with U-238 contamination differ substantially depending on
whether a site is contaminated with U-238 alone or with U-238 and all its progeny. At sites
where the long-lived progeny of U-238 are present, the potential impacts are dominated by
the Ra-226+D.
Insight into issues pertaining to the role of progeny and progeny ingrowth in a risk assessment
requires an understanding of the U-238 decay series depicted in Figure 3-11. In nature, all
members of the decay chain are present, often at a concentration that approximates that of the
their parent, U-238. However, environmental processes or the intervention of man often
result in the separation of the principal constituents of the decay chain. For example, uranium
ore contains all the progeny of U-238, but during processing the uranium is chemically
separated from the progeny, leaving just U-238 and U-234 (U-235 is also present, but for the
purposes of this discussion, it is not relevant due to its low abundance relative to U-238 and
U-234). This is the product generated at a uranium processing facility and is a primary
concern for the cleanup of these facilities.
At such facilities, the separated uranium, which includes both U-238 and U-234, begins to
decay, resulting in the ingrowth of progeny. Given enough time (i.e., millions of years), all
the progeny will eventually grow back in and have the same inventory and concentration of
the U-2383—a condition referred to as full equilibrium. The degree of equilibrium achieved
by any one progeny with its immediate parent is entirely a function of half-life. As a rule of
thumb, progeny equilibrium is achieved in about 10 half-lives of the progeny. Inspection of
Figure 3-11 reveals that the immediate progeny of U-238, Th-234, and Pa-234 have very
short half-lives. Thus, for all practical purposes, one can assume that these two radionuclides
are always present in full equilibrium with U-238 and every disintegration of U-238 is
accompanied by a disintegration of its short-lived daughters. As a result, U-238 is often
referred to as U-238+D, which means that its two short-lived progeny are assumed to always
be present in equilibrium.
3 The half-life of U-238 is so long (4.5E9 years) that its inventory remains virtually unchanged over millions of years. If its half-life
were substantially less than the age of the earth, it would have decayed away by now, along with all its progeny.
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If U-234 is initially present along with U-238, as it would be at a uranium processing facility,
the U-234 will undergo a series of transformations. However, its first progeny, Th-230, has a
half-life of 77,000 years. Accordingly, over a 100 time period of interest, very little Th-230
will be produced. As a result, the entire chain below U-234 is not a significant contributor to
risk for sites contaminated with uranium separated from its progeny. For a 1000 year time
period of interest, even the small amount of ingrowth results in a significant radon
contribution to risk. For a 10,000 time period of interest, some Th-230 grows in (about 5%
equilibrium) along with its progeny, including Ra-226+D. Because of the relatively high
impacts per curie of Ra-226+D, even 5% equilibrium is sufficient to cause indoor radon to
dominate the risks for the 10,000 year period of interest.
If natural uranium is present at a site, such as at a uranium mine or mill, the entire chain
is initially present at the site and the impacts are due to the sum of the impacts from
U-238+D, U-234, Th-230, Ra-226+D, and Pb-210+D. However, the time integrated impacts
from the entire decay chain are more than simply treating each radionuclide separately and
summing the results. As discussed above, for U-238+D, the impacts are derived assuming
that for each disintegration of U-238 there is also a disintegration of its short-lived daughters.
However, there is no need to consider the ingrowth of U-234 for time integration periods on
the order of 1000 or 10,000 years because its very long half-life precludes significant
ingrowth over such a relatively short time period.
This is not the case for a site already contaminated with U-234. Th-230 will grow in
sufficiently over 1000 or 10,000 years to warrant explicit consideration of progeny ingrowth
when evaluating the impacts of U-234. Similarly, the derivation of the time integrated
impacts from Th-230 requires explicit consideration of Ra-226 ingrowth, which has a half-life
of 1600 years. Explicit consideration of progeny ingrowth can be achieved through the use of
the Bateman equations, which is the method used to derive the impacts in this report.
However, the impacts from ingrowth can be conservatively approximated by assuming that
each disintegration of Th-230 is accompanied by a disintegration of all of its progeny. This
approach is conservative because over a 1000 or 10,000 year time period Ra-226 will not
achieve full equilibrium.
Ra-226 also has a series of short-lived daughters. Thus, when deriving the impacts from Ra-
226, as is the case for U-238, one assumes that for each disintegration of Ra-226 there is also
a disintegration of each of its daughters, including Pb-210 and its progeny.
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In Tables 3-21 through 3-23, the impacts reported for U-238+D are for U-238 alone with its
short-lived progeny, as would be the case for a depleted uranium site. Depleted uranium
means uranium depleted in U-235 and U-234. Depleted uranium is a byproduct of the
uranium enrichment process, whereby natural uranium is enriched in U-235 (and also in
U-234 due to the nature of the enrichment process—whereby any uranium with an atomic
weight less than that of U-235 is also enriched). Due to its very long half-life (i.e., 2.4E5
years), U-234 does not grow in, and only U-238 and its short-lived progeny are of interest in a
risk assessment at a DU site.
In Tables 3-21 through 3-23, the potential impacts from U-238+D are dominated by the
groundwater pathway. This occurs because of the high infiltration rate (0.5 m/yr) and
relatively low Kd for uranium (i.e., 15), which results in the relatively rapid transport of U-238
to the aquifer. However, for many sites, the transit time for uranium will exceed 1000, or
10,000 years, and therefore not arrive over the time period of interest. For example, for a
humid site with a 10 meter deep aquifer, an infiltration velocity of 1 m/yr and a typical
uranium Kd of 50, the transit time to the aquifer would be about 2500 years. As a result, for
many sites contaminated with U-238 alone (plus its short-lived daughters), the crop ingestion
pathway will likely dominate.
For U-238 alone, the time period of interest is particularly relevant because of its 4.4E9 year
half-life. The potential impacts of U-238 depend on whether it reaches the ground water
within the time period of interest. At many sites, the U-238 will require thousands of years to
reach the aquifer, thereby exceeding the time period of interest. Thus, the potential impacts
are reduced several-fold and the crop ingestion pathway dominates. Given the lack of a crop
ingestion pathway, the impacts are further reduced over 10-fold and are dominated by direct
radiation and dust inhalation.
For U-238, the assumed time period of interest can be critical because, due to its extremely
long half-life, U-238 does not decay and the potential cumulative population impacts increase
as the time integration period increases. Hence, as the time integration period increases, the
cumulative population impacts from U-238 increase from the water independent pathways.
Also, at some point in time, the U-238 reaches the groundwater and the potential impacts can
immediately increase 10-fold or more. In Tables 3-21 through 3-23, the impacts do not
increase greatly as the time integration period increases because a relatively low Kd and a
shallow aquifer were assumed which results in the relatively rapid depletion of the U-238
from the contaminated zone.
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Th-232. In many respects, the issue of the time period of interest for Th-232 is similar to that
of U-238 because it also has a very long half-life (i.e., 1.4E10 years). However, this issue is
less complex because Th-232's progeny, Ra-228+D, grow in virtually immediately4 (see
Figure 3-12). In Tables 3-21 through 3-23, the impacts for Th-232 were derived using the
Bateman equations. However, they could have been developed by simply assuming full
equilibrium with all its progeny, along with the assumption that the progeny are being
depleted from the contaminated zone at the same rate as the parent Th-232. Because of the
rapid buildup and continued presence of Ra-228, the direct radiation pathway quickly
dominates—even if Ra-228+D initially are not present at a site. Here, the cumulative
population dose is dominated by the direct radiation pathway and increases with the assumed
time period of interest.
Th-230. As discussed above, Th-230 is part of the U-238 series but can be present without its
parent and is typically present with its daughter, Ra-226. When present with is progeny, Ra-
226+D dominates the impacts. When Th-230 is initially present alone, Ra-226+D grows in
sufficiently even over short periods (i.e., 100 years) to dominate the impacts. As in the case
of U-238, when present, Ra-226 dominates the impacts. A very unique situation arises if Th-
230 is initially present alone. Its progeny, Ra-226, with a 1600 year half-life, grows in
sufficiently over a 1000 year time period to dominate the impacts. However, assuming a site
has a low Kd is not necessarily conservative. This occurs because, as the Ra-226 grows in, a
low Kd results in its rapid depletion from the contaminated zone. As with other radionuclides,
this results in increased impacts from the groundwater pathways, but the depletion reduces the
impacts from the indoor radon pathway, which is by far limiting. Accordingly, in the case of
Th-230, a low Kd is not necessarily a conservative assumption, as it is for other radionuclides.
Combined Pathways. Tables 3-21 through 3-23 also presents the numbers of cancers per
curie for sites where several exposure pathways exist simultaneously. Five scenarios are
included in Tables 3-21 through 3-23: rural (10 persons/km2, with and without agriculture),
intermediate (100 persons/km2, with and without agriculture), and suburban (1000
persons/km2, without agriculture).
4 Ra-228 has a 5.7 year half-life and as a result, within 50 years it is in equilibrium, along with all its progeny, with its parent.
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Figure 3-12. Th-232 Decay Series
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The number of total cancers per curie for the rural and intermediate scenarios are the sum of
each individual pathway—but with the impacts from the direct radiation, dust inhalation, and
indoor radon pathways reduced 100 and 10 fold, respectively. The number of total cancers
per curie for the suburban scenario is the sum of each pathway, except that the impacts from
the crop ingestion pathway are not included since a high population density (i.e., 1000
persons per km2) precludes the extensive use of the site for rural residential purposes. The
results reveal that for most radionuclides the suburban scenario is limiting.
3.2.2 Discussion of Pathway Uncertainties and Sensitivities
Uncertainty analyses are most appropriately applied to real sites where uncertainty
distributions can be applied to site-specific characteristics, such as the radionuclide
concentrations, area of contamination, thickness of the contaminated zone, depth to aquifer,
kd, hydraulic conductivity, etc. For a generic site, these parameters are "given" and little is
gained by assigning distributions to their values. Instead, a discussion of sensitivities is more
effective in disclosing how impacts for a generic site may change depending on alternative
assumptions regarding the site characteristics, land use, and demography. Nevertheless, it is
feasible to discuss the uncertainties in the generic values presented in Tables 3-21 through 3-
23 for each radionuclide and pathway, given the defined generic site.
A widely accepted method for quantifying uncertainties is the application of Monte Carlo
techniques. However, this method is of limited use, and may even be misleading if the
uncertainties in assumptions and distributions for the parameters are either large or ill defined.
Under these circumstances, as is recommended by Superfund Guidance (EPA 89a), one
should disclose uncertainties in a qualitative or semi-quantitative manner.
The following section presents a qualitative and semi-quantitative discussion of the
uncertainties associated with the generic estimates of the time integrated cumulative
population impacts associated with each of the exposure pathways.
Direct Radiation. The impacts from the direct radiation pathway in Tables 3-21 through 3-
23 are based on the assumption that the site's average population density over a 1000 year
time period is 1000 persons per km2 (typical of a suburban community). This assumption
alone may result in an upper bound estimate of direct radiation impacts because many real
sites are located in remote areas where they are unlikely to be heavily populated in the near
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future (see Appendix D). However, given these site conditions, the impacts for the generic
site—in Tables 3-21 through 3-23 (i.e., cancers per curie) for direct radiation—depend
primarily on the uncertainties in the values assigned to the external exposure slope factors,
which are effectively a function of the dose conversion factors and the risk conversion factor
for external exposure.
The external dose conversion factors, which convert radionuclide concentration in soil (pCi/g)
to dose rate (mrem/yr) are based on the dose conversion factors reported in Federal Guidance
Report No. 12. As discussed in (EPA 89b), the geometric standard deviation for external dose
conversion factors is about 1.4. This indicates the real value for the dose conversion factor
lies in a range of about 2.0 times higher (i.e., 2 sigma = 1.42) to 2.0 times lower than the value
used (i.e., an uncertainty range of 1 to 4 or an uncertainty of about 4 fold).
EPA 89b indicates the risk conversion factor for external whole body exposure has a
geometric standard deviation of 1.8. Accordingly, the approximate range of uncertainty in the
risk conversion factor is about a factor of 3.2 times higher and 3.2 times lower than the
reported value, or a factor of about 10 uncertainty. Further, the National Academy of
Sciences (NAS 90, p. 181) states: "since epidemiologic data cannot rigorously exclude the
existence of a threshold in the microsievert range,... there may be no risks from exposures
comparable to external natural background radiation." Thus, for low LET radiation and low
dose rates, the range of possible values for the dose to risk conversion factor should also
include zero. Accordingly, the range of the risk conversion factor can be from as low as 0 to
as high as about 2E-3 cancer per rem.
Propagating these sources of uncertainty and considering uncertainty in average occupancy
times and shielding factors (assumed to be uncertain by a factor of about 2 averaged over the
entire population), the uncertainty in the time integrated population impacts range from 0 to
an upper bound of about 7 times the derived value.5
5 The steps involved in propagating the uncertainty for values assigned a geometric standard deviation expressed as a multiplier of
the geometric mean are as follows:
1. Take the log of each GSD
2. Square each value
3. Add the squared values
4. take the square root of the sum
5. Take the antilog of that value
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The methodology used to derive the generic number of cancers per curie for direct radiation
and dust inhalation is based on the assumption that radioactivity is located in the top 2 m of
soil. This assumption results in a relatively low value for the number of cancers per curie for
the direct radiation and dust inhalation pathway because the radioactivity located at the site at
a depth greater than about 10 to 20 cm doses not contribute to the impacts from these
pathways. As a result, for a site where contamination extends down to two meters, the
number of cancers per curie for direct radiation and dust inhalation are a factor of about 10
lower than for a site where the "curie" is located in the top 20 cm.
For sites where the thickness of the contaminated zone is substantially less than 20 cm, the
number of cancers per curie for direct radiation and dust inhalation will be virtually
unchanged because the risk per Ci/m2 for each radionuclide is virtually constant for
contamination thicknesses less than about 20 cm. The reason is the radioactivity will likely
become generally mixed in the top 20 cm due to natural processes (wind suspension and
deposition and leaching) and the activities of man (e.g., plowing).
Federal Guidance Report No. 12 (EPA 93d) presents the external dose conversion factors for
individual radionuclides as a function of the thickness of the contaminated zone. The
following table presents the external dose conversion factors for selected key radionuclides as
a function of the thickness of the contaminated zone:
Isotope
Ba-137m
Co-60
Bi-214
Thickness of Contaminated Zone
(sv/sec per Bq/m3 EDE)
°° cm
1.93E-17
8.68E-17
5.25E-17
15 cm
1.71E-17
7.25E-17
4.36E-17
5 cm
1.09E-17
4.45E-17
2.68E-17
1 cm
3.76E-18
1.52E-17
9.15E-18
The dose rate relative to the infinite thick dose rate is as follows:
Three values have the following GSDs: 1.4, 1.8, and 2. The GSD of the product of the three values is as follows:
1. Log of each value is: .336, .588, and .693
2. The square of each value is: .113, .346, and .480
3. The sum is: .939
4. The square root of the sum is .969
5. The antilog is 2.6
Accordingly, the GSD of the product of the three values is a factor of 2.6 higher and 2.6 lower than the product. An expression of the full
range of uncertainty can be assumed to be 2 standard deviations, i.e., 2.62 or 6.8.
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Isotope
Ba-137m
Co-60
Bi-214
Relative External Dose Rate
<*> cm
1
1
1
15 cm
.89
.84
.83
5 cm
.56
.51
.51
1 cm
.19
.18
.17
This reveals that uncertainty in the thickness of the contaminated zone can contribute
significantly in the uncertainty in the external dose for gamma emitters if the thickness is less
than about 15 cm.
The time integrated impacts from direct radiation for a given radionuclide depend on the rate
at which the radionuclide is depleted from the zone of contamination that contributes to
external exposure, typically 15 to 20 cm. The depletion rate depends on the radionuclide
decay coefficient and the leach coefficient, which depends on the rainfall infiltration velocity
and the radionuclide retardation factor. For the generic site, a relatively high infiltration rate
and low retardation factors were employed. This elevates the risks to an individual from the
groundwater pathway, but tends to lower the time integrated cumulative number of cancers
per curie from the other pathways. For relatively short-lived radionuclides, like Co-60 and
Cs-137, the significance of this characteristic of the generic site is small because the depletion
rate from the soil is dominated by radioactive decay. However, for longer lived
radionuclides, such as Ra-226, a high leach rate results in a marked reduction in the time
integrated population impacts from the water-independent pathways. This issue is
demonstrated in the sensitivity analysis presented in Section 3.2.3.
Dust Inhalation. In addition to the thickness of the contaminated zone and the depletion rate,
the number of cancers per curie for the dust inhalation pathway at the generic site is based on
an assumed long-term average outdoor dust loading of 100 |ig/m3. In order to account for the
reduced dust loading indoors, a 0.5 adjustment factor is applied. This indoor/outdoor
connection factor is consistent with that employed in RESRAD, which uses a factor of 0.4,
and Alz 79, which observed a factor of 0.3. Dan 83 derived factors of 0.24, 0.32, and 0.19 for
a suburban house, a farm house, and a commercial building, respectively.
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Since the number of cancers per curie is proportional to the assumed dust loading, the impacts
can be adjusted up or down depending on the average dust loading at actual sites. The long
term average outdoor dust loading at an actual nonurban site can be as low as 1 to 10 |ig/m3
to about 100 |ig/m3. Dan 93 cites work by Anspaugh which showed several radionuclides at
four sites in the U.S. with a dust loading of 100 |ig/m3. Shinn's work is also cited which
reports dust loadings at the Nevada Test Site of 17 and 41 //g/m3. Also cited is Shah's work
where the geometric mean dust loading at 20 rural locations was 28 //g/m3 with a GSD of 1.6.
A review of dust loading is provided in NRC 92b and SEH 84.
The airborne dust loading can also be enriched or depleted in the contaminant as compared to
the contaminated soil. An enrichment factor of 1.0 is used in this analysis. A review of
enrichment factors is provided in EGG 84 and DAN 93.
Given the population density for the generic site, the uncertainty in the impacts for the dust
inhalation pathway primarily is due to the uncertainty in the average slope factor, adjustment
factor, average occupancy times, and average dust loading. The uncertainty in the inhalation
slope factors is reasonably approximated by a range of 0 to about 10 times the value used.6
Average occupancy times and indoor/outdoor decontamination factors may have a combined
variability of about 2 fold (i.e., 1.4 times higher and 1.4 times lower than the assumed value
of 0.5). The uncertainty in the soil particle suspension factor is very large. Sehmel and the
NRC report the uncertainty in this value is several orders of magnitude (Seh 84; NRC 92b).
However, when averaged over many sites and long time periods, the uncertainty is reduced,
and may be a factor of 10 to 100 fold lower than the assumed value of 100 |ig/m3 and is
unlikely to be any higher than this value. Other factors also contribute to uncertainty, but they
are not likely to add significantly to overall uncertainty as compared to the parameters above.
Groundwater Ingestion. The cumulative population impacts for the groundwater pathway
are based on the assumption that 50% of the leachate is withdrawn for domestic use and 1%
of that is consumed. In addition, no credit is taken for radioactive decay in transit from the
6 This report does not attempt to explicitly quantify the uncertainties in the inhalation and ingestion slope factors. However, based
on discussions provided in EPA 89 regarding the uncertainties in the dose conversion factors and risk conversion factor for the
average member of the public, a factor of 10 times the reported values for the slope factors was selected as a generally reasonable
interim upper bound.
Review Draft - 9/26/94 3-97 Do Not Cite Or Quote
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aquifer to receptor locations (credit is taken for decay in transit in the unsaturated zone).
These assumptions alone result in upper bound values for the time integrated population dose
for the groundwater pathway. However, given these assumptions, the uncertainty in the time
integrated population impacts for the groundwater pathway is due primarily to the uncertainty
in the slope factors, which range from 0 to about a factor of 10 higher than the values used.
As a result, the impacts could range from 0 to about 10 times higher than the derived values.
The generic site's number of cancers per curie for the groundwater pathway is an upper bound
value because of the assumed groundwater usage described above and also because the
assumptions tend to maximize the rate at which radionuclides are transported to the
groundwater. For example, low end Kd values along with a shallow unsaturated zone and
high infiltration rate result in minimal radioactive decay prior to transport to receptors. Any
change in these assumptions will likely result in a reduction in the number of cancers per
curie.
Crop Ingestion. The cumulative population impacts for the crop ingestion pathway are
based on the assumptions: the entire site is used for rural residential purposes over a 1000
year period and all the crops are consumed. This results in an upper bound estimate of the
impacts for this pathway. However, given these assumptions, the uncertainty in the
cumulative population impacts for this pathway is primarily due to uncertainties in the soil-to-
plant transfer factors and the ingestion slope factors. For individual plants at specific
locations, these transfer factors, often referred to as Bvs, can vary by orders of magnitude.
When used as average values representing large areas, long time periods, and a broad range of
types of vegetation, the uncertainty in the Bvs is markedly reduced. As discussed in (EPA
89b), the uncertainty in the soil to plant transfer factors are isotope specific and may range
from about a factor of 10 higher to a factor of 10 lower than the values used in this analysis.
Insight into variability in the Bvs is also provided in the compilation of soil-to-vegetable
transfer factors provided in (ANL 93a, Pet 83, Sim 90, and IAEA 82).
Imbedded in the use of the Bv approach to calculating the radionuclide concentration in
vegetable crops are assumptions regarding the average concentration of the radionuclides in
the soil horizon. In this analysis, the average radionuclide concentration in the top 0.9 m of
soil is used. This means that if the contaminated soil extends to depth of only 0.09 m, the
radionuclide concentration in the contaminated zone is diluted 10-fold since one must assume
Review Draft - 9/26/94 3-98 Do Not Cite Or Quote
-------
the Bv values apply to the average radionuclide concentration in the 0.9 m root zone. As
indicated in (ANL 93b), the root zone, from which the radionuclides are obtained, ranges
from about 0.3 to 5 m.
The models assume an average productivity of 0.718 kg/yr per m2 (EPA 89b). This is the
productivity of a parcel of land dedicated to agriculture and therefore is an upper end
estimate. Table 3-25 presents the agricultural productivity of different crops. As may be
noted, the values selected is not bounding. However, it is considered conservative because it
is assumed to persist for the entire time periods of interest.
The time integrated population impacts are also a function of the radionuclide depletion rate
from the root zone, which is assumed to be 0.9 meters. As discussed above, high infiltration
rates and low Kds were selected for the generic site because they tend to increase the impacts
from the groundwater pathway. However, these assumptions result in a rapid clearance from
the root zone, thereby reducing the time integrated impacts.
In this analysis, the Bvs are treated as independent of the Kds. However, it is reasonable to
assume that the two parameters are coupled because a higher Kd will tend to make the
radionuclide less available in the dissolved state. The use of low Kds simultaneously tends to
reduce the time integrated impacts due to rapid depletion from the root zone, but increase the
impacts because of the likelihood of higher Bvs.
Taken together with the uncertainty in the slope factors, the uncertainty in the cumulative
population impacts for the vegetable pathway can range from 0 to about a factor of 10 to 100
fold higher than the derived values. The upper end values are due to the possibility of
localized high Bv values.
Indoor Radon. Given the assumed time averaged population density of 1000 persons per
km2, the uncertainty in the cumulative population impacts due to exposure to indoor radon is:
(1) assumed relationship between the average indoor radon concentration (pCi/L) and the
average Ra-226 concentration (pCi/g) in soil (i.e., the concentration ratio), and (2) the
assumed risk of cancer per working level month (i.e., the risk factor). There are other sources
of uncertainty, such as the average fractional equilibrium, the unattached fraction, and the
occupancy times, but they are either part of, or a small fraction of, the uncertainties in the
concentration ratio and risk factor for indoor radon.
Review Draft - 9/26/94 3-99 Do Not Cite Or Quote
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Table 3-25. Agricultural Productivity
PRINCIPAL VEGETABLES FOR FRESH MARKETS
Crop
Artichokes
Asparagus
Beans, Lima
Beans, Snap
Broccoli
Brussel Sprouts
Cabbage
Cantaloupes
Carrots
Cauliflower
Celery
Corn, Sweet
Cucumbers
Eggplant
Escarole/Endive
Garlic
Honey dew
Lettuce, Head
Lettuce, Leaf
Lettuce,Romaine
Onions
Bell Peppers
Spinach
Tomatoes
Watermelons
Production
(1,000 kg)
1992
50,076
106,639
5,579
175,902
564,583
25,401
912,260
790,653
1,507,779
317,921
872,798
808,932
440,980
40,007
24,358
172,137
196,858
3,211,871
373,531
256,369
2,482,543
643,463
106,639
1,731,943
1,646,985
1993
44,406
99,971
4,354
192,005
489,832
27,578
996,310
841,455
1,461,966
301,910
826,033
770,468
454,860
35,199
25,900
161,932
152,406
3,075,975
379,655
299,642
2,567,138
626,000
122,515
1,599,630
1,666,490
Area Planted
(1,000 m2)
1992
38,850
357,825
16,997
367,659
451,632
14,164
319,299
450,013
437,063
230,267
138,080
922,284
219,948
14,973
19,425
93,078
103,600
877,525
156,210
81,342
601,771
274,378
80,938
549,323
1,028,4
74
1993
36,017
344,632
19,020
402,260
434,635
15,378
309,870
443,862
422,089
231,481
132,859
903,628
263,452
12,950
17,685
84,984
84,580
844,179
164,222
103,195
637,383
266,608
88,222
552,601
908,039
Yield
(kg/m2)
1992
1.29
0.30
0.33
0.48
1.25
1.79
2.86
1.76
3.45
1.38
6.32
0.88
2.00
2.67
1.25
1.85
1.90
3.66
2.39
3.15
4.13
2.35
1.32
3.15
1.60
1993
1.23
0.29
0.23
0.48
1.13
1.79
3.22
1.90
3.46
1.30
6.22
0.85
1.73
2.72
1.46
1.91
1.80
3.64
2.31
2.90
4.03
2.35
1.39
2.89
1.84
Avg.
1.26
0.29
0.28
0.48
1.19
1.79
3.04
1.83
3.46
1.34
6.27
0.86
1.87
2.69
1.36
1.88
1.85
3.65
2.35
3.03
4.08
2.35
1.35
3.02
1.72
Source: U.S. Department of Agriculture, Economic Research Service
Review Draft - 9/26/94
3-100
Do Not Cite Or Quote
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Table 3-25. (Continued)
PRINCIPAL VEGETABLES FOR PROCESSING
Crop
Beans, Lima
Beans, Snap
Beets
Cabbage
Corn, Sweet
Cucumbers
Peas, Green
Spinach
Tomatoes
Production
(1,000 kg)
1992
36,272
585,787
106,776
156,662
2,951,492
506,186
516,463
92,490
7,961,388
1993
42,766
591,410
103,574
122,014
2,465,070
532,408
319,075
117,125
8,776,907
Area Planted
(1,000 m2)
1992
129,055
823,783
31,363
25,576
2,157,674
437,710
1,454,974
56,535
1,121,431
1993
150,949
812,532
29,259
25,253
2,025,949
463,651
1,006,459
64,264
1,280,433
Yield
(kg/m2)
1992
0.28
0.71
3.40
6.13
1.37
1.16
0.35
1.64
7.10
1993
0.28
0.73
3.54
4.83
1.22
1.15
0.32
1.82
6.85
Avg
0.28
0.72
3.47
5.48
1.29
1.15
0.34
1.73
6.98
Source: U.S. Department of Agriculture, Economic Research Service
Review Draft - 9/26/94
3-101
Do Not Cite Or Quote
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For any individual home, the ratio of indoor radon concentration (pCi/L) per pCi/g of Ra-226 in
soil can range from less than one to several orders of magnitude. For example, data summarized
in SCA 89 for 73 homes in a community with soil containing elevated levels of Ra-226 revealed
average Ra-226 concentrations in soil ranging from 0.65 to 61.3 pCi/g. Indoor radon progeny
concentrations ranged from 0.001 to 1.549 WL. The latter correspond to indoor radon
concentrations ranging from 0.2 to 300 pCi/L. The radon ratio ranged from 0.04 to 50. The
geometric mean of this range is 1.4.
The variability in the ratio is likely to be relatively small when the parameter of interest is the
average ratio for large populations and long time periods of interest. As indicated in EPA 82, "...
one might expect indoor radon decay product concentrations of 0.01 WL (this corresponds to
about 2 pCi/L of radon assuming a typical indoor fractional equilibrium of 50% for radon
progeny - this note is not included in the quote) for soils with radium concentrations of 1 to 3
pCi/g to a depth of 1 meter or more." Based on this relationship, the average ratio employed in
this report is 1.25.
In this report, the risk factor is 240 lung cancer deaths per 1E6 WLM7. The reported range is
140 to 720, and the possibility of zero impacts at low exposure rates cannot be ruled out (EPA
89b). Accordingly, given the assumed population density, the uncertainty in the cumulative
population impacts can range from 0 to about a factor of 5 greater than the derived values.
As with the other water-independent pathways, the time integrated impacts are a function of the
depletion rate of radium in the zone of interest. The zone of interest for radon is assumed to be 5
meters based on RAE 90. Since a low Kd and high infiltration rate was assumed for the generic
site, the time integrated impacts would increase for this pathway at sites with lower soil depletion
rates.
In summary, given the generic site conditions, the values tabulated in Tables 3-21 through 3-23
can range from 0 to about 5 to 10 times higher (and to as much as 100 times higher for some
radionuclides for the crop ingestion pathway) than the indicated values. An attempt
7 This value is based on the supporting documentation to EPA's "A Citizen's Guide to Radon, (Second Edition)" ANR-464, May
1992 Citizen Guide. The risk coefficient reported in EPA 89 is 360 cancers per 1E6 WLM.
Review Draft - 9/26/94 3-102 Do Not Cite Or Quote
-------
can be made to derive a more precise estimate of the uncertainty for individual pathways and
radionuclides. However, given the nature of the uncertainties in the calculational parameters,
little value will be added—and this may even produce misleading results.
3.2.3 Quantitative Sensitivity Analysis
The above discussion presents a qualitative evaluation of the sensitivity of the generic cancers
per curie for alternative assumptions regarding the characteristics of the contaminated soil and
the environmental setting. This section presents the results of a quantitative sensitivity analysis
demonstrating some of the sensitivities discussed above.
All values in Tables 3-21 through 3-23 are directly proportional to the slope factor, which, as
discussed above can range from 0 to about 10 times the assumed value. For direct radiation,
dust inhalation, and indoor radon, the results are directly proportional to the assumed population
density. In Tables 3-21 through 3-23, the population density is assumed to be 1000 persons/km2.
For the groundwater ingestion pathway, the results are directly proportional to the fraction of the
contaminated groundwater that is consumed. In Tables
3-21 through 3-23, an assumed 50% of the groundwater is withdrawn and 1% of this is
consumed. For the crop ingestion pathway, the values in Tables 3-21 through 3-23 are directly
proportional to the assumed soil-to-plant transfer factors and the crop production rate. For the
indoor radon pathway, the values are directly proportional to the radon concentration ratio. The
values in Tables 3-21 through 3-23 can be prorated up or down in proportion to the alternative
values for these parameters. However, there are several parameters that affect the results in a
non-linear manner. The most important of these include the Kds, the thickness of the
contaminated zone, and the time period of interest. The following discussion demonstrates the
sensitivity of the results for alternative values of these parameters.
Increasing the Kds. Tables 3-26 through 3-28 are identical to Tables 3-21 through 3-23 except
high end Kd values are assumed. This greatly reduces the downward velocity of the
radionuclides in the unsaturated zone—thereby delaying the arrival of radionuclides in the
underlying aquifer—but increases the residence time in the contaminated zone. This effectively
reduces the potential for exposure via the groundwater pathway but increases the potential for
exposure by the direct radiation, dust inhalation, crop ingestion, and indoor radon pathways. A
similar effect is realized by reducing the infiltration rate. The results are significant for several
radionuclides and pathways. The following summarizes the results for the 1000 year period of
interest.
Review Draft - 9/26/94 3-103 Do Not Cite Or Quote
-------
Table 3-26. Generic Population Impacts (Case 2) Expressed on a per Curie Basis (100 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 100 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
1.13E-02
1.25E-02
O.OOE+00
6.86E-07
1.90E-07
1.01E-01
4.21E-03
O.OOE+00
5.47E-11
2.64E-03
2.21E-03
1.31E-01
9.57E-07
3.85E-03
8.31E-04
Dust
Inhalation
5.90E-08
8.44E-08
2.12E-06
1.35E-05
3.10E-04
7.29E-05
9.41E-07
2.04E-07
1.89E-10
3.04E-05
1.98E-04
1.21E-03
1.49E-04
1.39E-04
1.33E-04
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
1.14E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
Crop
Ingestion
9.63E-05
3.53E-03
3.30E-06
2.66E-02
1.36E-04
1.03E-01
2.95E-04
4.69E-02
6.92E-04
5.19E-06
1.46E-03
3.45E-03
1.68E-03
1.78E-03
2.34E-03
Radon
Inhalation
5.65E-01
1.23E-02
3.71E-06
Rural With
Agricultureb
2.10E-04
3.66E-03
3.32E-06
2.66E-02
1.39E-04
1.10E-01
3.37E-04
4.69E-02
1.83E-03
3.19E-05
1.60E-03
4.77E-03
1.68E-03
1.82E-03
2.35E-03
Rural
Without
Agricultureb
1.13E-04
1.25E-04
2.12E-08
1.42E-07
3.10E-06
6.66E-03
4.21E-05
2.04E-09
1.14E-03
2.67E-05
1.47E-04
1.33E-03
1.54E-06
3.99E-05
9.64E-06
Intermediary
With
Agricultureb
1.23E-03
4.78E-03
3.51E-06
2.66E-02
1.67E-04
1.70E-01
7.17E-04
4.69E-02
1.83E-03
2.72E-04
2.93E-03
1.67E-02
1.70E-03
2.18E-03
2.44E-03
Intermediary
Without
Agriculture13
1.13E-03
1.25E-03
2.12E-07
1.42E-06
3.10E-05
6.66E-02
4.21E-04
2.04E-08
1.14E-03
2.67E-04
1.47E-03
1.33E-02
1.54E-05
3.99E-04
9.64E-05
Suburban
Without
Agriculture13
1.13E-02
1.25E-02
2.12E-06
1.42E-05
3.10E-04
6.66E-01
4.21E-03
2.04E-07
1.14E-03
2.67E-03
1.47E-02
1.33E-01
1.54E-04
3.99E-03
9.64E-04
(a) Depth of contaminated zone is equal to 2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the high-end set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-27. Generic Population Impacts (Case 2) Expressed on a per Curie Basis (1000 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 1,000 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
1.13E-02
1.38E-02
O.OOE+00
7.18E-07
1.57E-06
7.64E-01
4.21E-03
O.OOE+00
5.47E-11
2.64E-03
1.82E-01
1.43E+00
4.25E-04
2.30E-02
4.95E-03
Dust
Inhalation
5.90E-08
9.33E-08
2.12E-06
1.41E-05
2.57E-03
5.51E-04
9.41E-07
2.09E-07
1.89E-10
3.04E-05
2.07E-03
1.30E-02
8.95E-04
8.28E-04
7.94E-04
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
8.35E-14
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
8.29E-16
1.14E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
Crop
Ingestion
9.63E-05
3.93E-03
3.31E-06
2.79E-02
1.30E-03
8.40E-01
2.95E-04
5.05E-02
6.92E-04
5.19E-06
1.86E-01
3.73E-02
1.58E-02
1.61E-02
2.13E-02
Radon
Inhalation
4.67E+00
1.08E+00
3.33E-03
Rural With
Agricultureb
2.10E-04
4.06E-03
3.33E-06
2.79E-02
1.32E-03
8.95E-01
3.37E-04
5.05E-02
1.83E-03
3.19E-05
1.99E-01
5.17E-02
1.59E-02
1.64E-02
2.13E-02
Rural
Without
Agricultureb
1.13E-04
1.38E-04
2.12E-08
1.48E-07
2.57E-05
5.43E-02
4.21E-05
2.09E-09
1.14E-03
2.67E-05
1.27E-02
1.44E-02
4.65E-05
2.38E-04
5.75E-05
Intermediary
With
Agricultureb
1.23E-03
5.31E-03
3.52E-06
2.79E-02
1.56E-03
1.38E+00
7.17E-04
5.05E-02
1.83E-03
2.72E-04
3.13E-01
1.82E-01
1.63E-02
1.85E-02
2.18E-02
Intermediary
Without
Agricultureb
1.13E-03
1.38E-03
2.12E-07
1.48E-06
2.57E-04
5.43E-01
4.21E-04
2.09E-08
1.14E-03
2.67E-04
1.27E-01
1.44E-01
4.65E-04
2.38E-03
5.75E-04
Suburban
Without
Agricultureb
1.13E-02
1.38E-02
2.12E-06
1.48E-05
2.57E-03
5.43E+00
4.21E-03
2.09E-07
1.14E-03
2.67E-03
1.27E+00
1.44E+00
4.65E-03
2.38E-02
5.75E-03
(a) Depth of contaminated zone is equal to 2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the high-end set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-28. Generic Population Impacts (Case 2) Expressed on a per Curie Basis (10,000 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 10,000 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
1.13E-02
1.38E-02
O.OOE+00
7.18E-07
4.38E-06
1.58E+00
4.21E-03
O.OOE+00
5.47E-11
2.64E-03
5.05E+00
1.30E+01
3.21E-02
3.15E-02
6.80E-03
Dust
Inhalation
5.90E-08
9.33E-08
2.12E-06
1.41E-05
7.16E-03
1.14E-03
9.41E-07
2.09E-07
1.89E-10
3.04E-05
2.04E-02
1.19E-01
1.35E-03
1.14E-03
1.09E-03
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
8.35E-14
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
1.33E-15
1.14E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
Crop
Ingestion
9.63E-05
3.93E-03
3.31E-06
2.79E-02
8.73E-03
2.22E+00
2.95E-04
5.05E-02
6.92E-04
5.19E-06
7.23E+00
3.69E-01
2.31E-01
7.33E-02
9.65E-02
Radon
Inhalation
1.30E+00
4.23E+01
1.43E+00
Rural With
Agriculture11
2.10E-04
4.06E-03
3.33E-06
2.79E-02
8.80E-03
2.36E+00
3.37E-04
5.05E-02
1.83E-03
3.19E-05
7.70E+00
5.00E-01
2.45E-01
7.36E-02
9.66E-02
Rural
Without
Agricultureb
1.13E-04
1.38E-04
2.12E-08
1.48E-07
7.16E-05
1.45E-01
4.21E-05
2.09E-09
1.14E-03
2.67E-05
4.74E-01
1.31E-01
1.47E-02
3.27E-04
7.90E-05
Intermediary
With
Agricultureb
1.23E-03
5.31E-03
3.52E-06
2.79E-02
9.45E-03
3.67E+00
7.17E-04
5.05E-02
1.83E-03
2.72E-04
1.20E+01
1.68E+00
3.77E-01
7.66E-02
9.73E-02
Intermediary
Without
Agriculture11
1.13E-03
1.38E-03
2.12E-07
1.48E-06
7.16E-04
1.45E+00
4.21E-04
2.09E-07
1.14E-03
2.67E-04
4.74E+00
1.31E+00
1.47E-01
3.27E-03
7.90E-05
Suburban
Without
Agriculture11
1.13E-02
1.38E-02
2.12E-06
1.48E-05
7.16E-03
1.45E+01
4.21E-03
2.09E-07
1.14E-03
2.67E-03
4.74E+01
1.31E+01
1.47E+00
3.27E-02
7.90E-03
(a) Depth of contaminated zone is equal to 2 meters. Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the high-end set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
For Co-60, Cs-137, and Ra-228+D, the use of high end Kds results in a less than 2-fold increase in the
numbers of cancers per curie. This modest increase is expected because the residence time of these
radionuclides is dominated by their decay rate—and this occurs even as higher Kds increase residence
times in the contaminated zone.
For H-3, the results change substantially because the high end Kd is assumed to be 42 instead of 0.
This high end value reported for tritium is reasonable for the organically bound tritium considered
here. Note the impacts from the groundwater pathway decline markedly due to holdup in the
contaminated and unsaturated zone, but the impacts from the other pathways increase substantially.
The impacts for Tc-99 change in a similar manner when going from the base case Kds to the upper end
Kds.
For Pu-239 and Ra-226+D, impacts from all water independent pathways increase due to increased
residence times in the contaminated zone. The impacts from the groundwater pathway remain at zero
because even the low base line Kds are relatively large, thereby preventing the Pu-239 and Ra-226+D
from reaching the aquifer within the 1000 year time period.
Sr-90+D is affected in a complex manner. Groundwater, a previously important pathway, is virtually
eliminated, but the crop ingestion pathway, also previously important, is increased about 2-fold. Thus,
the impacts for the rural residential scenario are reduced by a factor of about two, while the suburban
scenario impacts are virtually eliminated due to the elimination of the groundwater pathway.
Th-232 shows a small increase (less than a factor of 2) because even the base line Kd for Th-232 is
relatively large. As a result, the impacts from the critical pathway (i.e., direct radiation from its
immediate progeny Ra-228+D) increase only slightly.
U-238+D is also affected in a complex manner. The groundwater pathway, which was previously
dominant, is eliminated, and the water independent pathways increase substantially due the increased
residence times. The overall effect is an increase in the potential impacts.
Decreasing the Thickness of the Contaminated Zone. A second case is run identical to the high Kd
case but here the thickness of the contaminated zone is 20 cm as opposed to 2.0 meters. This places
the "curie" in the top 20 cm, as opposed to diluting it over a 2 meter depth. Tables 3-29 through 3-31
present the results of this analysis.
Review Draft - 9/26/94 3-107 Do Not Cite Or Quote
-------
As may be expected, the number of cancers per curie for the direct radiation and dust inhalation
pathways increase about 10-fold. The water ingestion pathway remains unchanged, and the impacts
from the crop ingestion pathway increase about 3-fold. The overall effect is a small increase in the
rural residential scenario, but a large (about 10-fold) increase in the suburban scenario for all
radionuclides except Ra-226, H-3, and Tc-99. The 10-fold increase is expected because the activity is
assumed to be in the areas that are only affected by the contamination in the top layers of soil (i.e.,
direct radiation). H-3 and Tc-99 remain unchanged because the groundwater pathway is virtually
unaffected by the distribution pattern of the activity in the unsaturated zone. Ra-226 remains
unchanged because the total number of curies available for diffusion into homes remains unchanged
(i.e., the average concentration over a 0 to 5 m depth remains the same whether the curie is assumed to
be located in a 0 to 20 cm or 0 to 2 meter contaminated zone.
Alternative Time Periods of Interest. For each of the above three cases, the time integrated number
of cancers per Ci was derived for time integration periods of 100, 1000, and 10,000 years. Figure 3-13
summarizes the results for the base case suburban future use scenarios for selected representative
radionuclides. The results reveal that the total numbers of cancers per curie remain virtually
unchanged for Cs-137, Tc-99, and U-238, but change substantively for the other radionuclides. The
impacts remain the same for Cs-137 because its half life is only 30 years, and therefore, the integrated
dose is the same for all three time periods. In general, any radionuclide with a half life significantly
less than 100 years, such as Sr-90, Co-60, and H-3, will have the same cumulative impacts for any
integration period greater than 100 years.
Tc-99 and U-238 remain unchanged because of the assumed low Kds and a high infiltration rate. This
produces a short residence time for these radionuclides in the contaminated zone— compared to 100
years—and, therefore, the time integration period has little effect. If higher Kds or lower infiltration
rates are assumed, the impacts for these radionuclides over different time periods would change.
Review Draft - 9/26/94 3-108 Do Not Cite Or Quote
-------
Table 3-29. Generic Population Impacts (Case 3) Expressed on a per Curie Basis (100 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 100 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
1.02E-01
1.16E-01
O.OOE+00
6.73E-06
1.89E-06
8.88E-01
3.75E-02
O.OOE+00
5.46E-10
2.15E-02
1.94E-02
1.10E+00
8.76E-06
3.81E-02
7.67E-03
Dust
Inhalation
5.90E-07
8.44E-07
2.12E-05
1.35E-04
3.10E-03
7.29E-04
9.41E-06
2.04E-06
1.89E-09
3.04E-04
1.98E-03
1.21E-02
1.49E-03
1.39E-03
1.33E-03
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
1.14E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
Crop
Ingestion
2.14E-04
7.85E-03
7.33E-06
5.92E-02
3.01E-04
2.29E-01
6.56E-04
1.04E-01
1.54E-03
1.15E-05
3.23E-03
7.67E-03
3.74E-03
3.95E-03
5.20E-03
Radon
Inhalation
5.65E-01
1.23E-02
3.71E-06
Rural With
Agricultureb
1.23E-03
9.01E-03
7.55E-06
5.92E-02
3.32E-04
2.43E-01
1.03E-03
1.04E-01
2.67E-03
2.29E-04
3.57E-03
1.88E-02
3.75E-03
4.34E-03
5.29E-03
Rural
Without
Agricultureb
1.02E-03
1.16E-03
2.12E-07
1.42E-06
3.10E-05
1.45E-02
3.75E-04
2.04E-08
1.14E-03
2.18E-04
3.37E-04
1.11E-02
1.50E-05
3.95E-04
9.01E-05
Intermediary
With
Agricultureb
1.04E-02
1.94E-02
9.46E-06
5.92E-02
6.12E-04
3.74E-01
4.40E-03
1.04E-01
2.67E-03
2.19E-03
6.61E-03
1.19E-01
3.89E-03
7.90E-03
6.10E-03
Intermediary
Without
Agricultureb
1.02E-02
1.16E-02
2.12E-06
1.42E-05
3.10E-04
1.45E-01
3.75E-03
2.04E-07
1.14E-03
2.18E-03
3.37E-03
1.11E-01
1.50E-04
3.95E-03
9.01E-04
Suburban
Without
Agriculture11
1.02E-01
1.16E-01
2.12E-05
1.42E-04
3.10E-03
1.45E+00
3.75E-02
2.04E-06
1.14E-03
2.18E-02
3.37E-02
1.11E+00
1.50E-03
3.95E-02
9.01E-03
(a) Depth of contaminated zone is equal to 0.2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the high-end set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-30. Generic Population Impacts (Case 3) Expressed on a per Curie Basis (1,000 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 1,000 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+D"
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230c
Th-232c
U-234C
U-235+D
U-238+D
Direct
Radiation
1.02E-01
1.28E-01
O.OOE+00
7.04E-06
1.56E-05
6.71E+00
3.75E-02
O.OOE+00
5.46E-10
2.15E-02
1.60E+00
1.20E+01
3.74E-03
2.27E-01
4.58E-02
Dust
Inhalation
5.90E-07
9.33E-07
2.12E-05
1.41E-04
2.57E-02
5.51E-03
9.41E-06
2.09E-06
1.89E-09
3.04E-04
2.07E-02
1.30E-01
8.95E-03
8.28E-03
7.94E-03
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
5.36E-13
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
7.15E-15
1.14E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
Crop
Ingestion
2.14E-04
8.73E-03
7.35E-06
6.19E-02
2.89E-03
1.87E+00
6.56E-04
1.12E-01
1.54E-03
1.15E-05
4.14E-01
8.28E-02
3.52E-02
3.59E-02
4.72E-02
Radon
Inhalation
4.67E+00
1.08E+00
3.33E-03
Rural With
Agricultureb
1.23E-03
l.OOE-02
7.56E-06
6.19E-02
3.14E-03
1.98E+00
1.03E-03
1.12E-01
2.67E-03
2.29E-04
4.41E-01
2.04E-01
3.53E-02
3.82E-02
4.78E-02
Rural
Without
Agriculture11
1.02E-03
1.28E-03
2.12E-07
1.48E-06
2.57E-04
1.14E-01
3.75E-04
2.09E-08
1.14E-03
2.18E-04
2.70E-02
1.21E-01
1.60E-04
2.35E-03
5.37E-04
Intermediary
With
Agriculture11
1.04E-02
2.15E-02
9.47E-06
6.20E-02
5.46E-03
3.01E+00
4.40E-03
1.12E-01
2.67E-03
2.19E-03
6.84E-01
1.30E+00
3.68E-02
5.94E-02
5.26E-02
Intermediary
Without
Agricultureb
1.02E-02
1.28E-02
2.12E-06
1.48E-05
2.57E-03
1.14E+00
3.75E-03
2.09E-07
1.14E-03
2.18E-03
2.70E-01
1.21E+00
1.60E-03
2.35E-02
5.37E-03
Suburban
Without
Agricultureb
1.02E-01
1.28E-01
2.12E-05
1.48E-04
2.57E-02
1.14E+01
3.75E-02
2.09E-06
1.14E-03
2.18E-02
2.70E+00
1.21E+01
1.60E-02
2.35E-01
5.37E-02
(a) Depth of contaminated zone is equal to 0.2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the high-end set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
Table 3-31. Generic Population Impacts (Case 3) Expressed on a per Curie Basis (10,000 Years)
Normalized Population Health Impacts (cancers per Ci)
For An Integration Period of 10,000 Years
Radionuclide
Co-60
Cs-137+D
H-3
Pb-210+D
Pu-239
Ra-226+Dc
Ra-228+D
Sr-90+D
Tc-99
Th-228+D
Th-230d
Th-232d
U-234"
U-235+D
U-238+D
Direct
Radiation
1.02E-01
1.28E-01
O.OOE+00
7.04E-06
4.36E-05
1.38E+01
3.75E-02
O.OOE+00
5.46E-10
2.15E-02
4.44E+01
1.09E+02
2.82E-01
3.12E-01
6.29E-02
Dust
Inhalation
5.90E-07
9.33E-07
2.12E-05
1.41E-04
7.16E-02
1.14E-02
9.41E-06
2.09E-06
1.89E-09
3.04E-04
2.04E-01
1.19E+00
1.35E-02
1.14E-02
1.09E-02
Ground
Water
Ingestion
O.OOE+00
O.OOE+00
5.36E-13
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
9.70E-15
1.14E-03
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
Crop
Ingestion
2.14E-04
8.73E-03
7.35E-06
6.19E-02
1.94E-02
4.92E+00
6.56E-04
1.12E-01
1.54E-03
1.15E-05
1.61E+01
8.20E-01
5.13E-01
1.63E-01
2.15E-01
Radon
Inhalation
1.30E+01
4.23E+01
1.43E+00
Rural With
Agricultureb
1.23E-03
l.OOE-02
7.56E-06
6.19E-02
2.01E-02
5.19E+00
1.03E-03
1.12E-01
2.67E-03
2.29E-04
1.69E+01
1.92E+00
5.30E-01
1.66E-01
2.15E-01
Rural
Without
Agricultureb
1.02E-03
1.28E-03
2.12E-07
1.48E-06
7.16E-04
2.68E-01
3.75E-04
2.09E-08
1.14E-03
2.18E-04
8.70E-01
1.10E+00
1.73E-02
3.23E-03
7.38E-04
Intermediary
With
Agricultureb
1.04E-02
2.15E-02
9.47E-06
6.20E-02
2.66E-02
7.61E+00
4.40E-03
1.12E-01
2.67E-03
2.19E-03
2.48E+01
1.19E+01
6.86E-01
1.95E-01
2.22E-01
Intermediary
Without
Agricultureb
1.02E-02
1.28E-02
2.12E-06
1.48E-05
7.16E-03
2.68E+00
3.75E-03
2.09E-07
1.14E-03
2.18E-03
8.70E+00
1.10E+01
1.73E-01
3.23E-02
7.38E-03
Suburban
Without
Agricultureb
1.02E-01
1.28E-01
2.12E-05
1.48E-04
7.16E-02
2.68E+01
3.75E-02
2.09E-06
1.14E-03
2.18E-02
8.70E+01
1.10E+02
1.73E+00
3.23E-01
7.38E-02
(a) Depth of contaminated zone is equal to 0.2 meters.
Infiltration rate is equal to 0.5 meters per year.
Kd is equal to the high-end set of values.
Unsaturated zone thickness is equal to 2 meters.
Removal mechanisms include leaching and decay.
Population density equals 1,000 people/square kilometer.
Results that are less than l.OOE-20 are reported as O.OOE+00.
(b) Rural scenario is based on a population density of 10 ind/km2.
Intermediary scenario is based on a population density of 100 ind/km2.
Suburban scenario is based on a population density of 1,000 ind/km2.
(c) Ra-226+D assumes Pb-210 and its progeny to be in secular equilibrium with Ra-226.
(d) The results for this radionuclide include the effects of progeny ingrowth.
-------
ft
O
o
O
??
O
O
o,
FT
Figure 3-13. Generic Population Impacts
Suburban Scenario
Cancers Per Curie
100
10
0.1
0.01
0.001
0.0001
Cs-137
Ra-226+D
D 100
Yrs
Tc-99
Pu-239
U-238+D
Th-232
1,000
Yrs
10,000
Yrs
-------
The impacts for the remaining radionuclides change substantively for different time integration periods
because the radionuclides do not deplete rapidly (either by radioactive decay or leaching) over the
different time periods of interest. As a result, the longer the time integration period the larger the
integrated impacts.
Effect of Future land use Scenario. Figure 3-14 compares the 1000 year integrated impacts for
selected radionuclides for the different future land use scenarios for the base case. For Cs-137+D, Ra-
226+D, and Th-232, the results reveal the suburban scenario clearly dominates because the water
independent pathways dominate. For Tc-99 and U-238+D, the results are virtually the same for all
scenarios because the groundwater pathway dominates. For Pu-239, the results are significantly
affected by whether or not agriculture is assumed.
Review Draft - 9/26/94 3-113 Do Not Cite Or Quote
-------
ft
O
o
O
??
O
O
o,
FT
Figure 3-14. Generic Population Impacts
1000 Year Case
Cancers Per Curie
10
0.1
0.01
0.001
0.0001
0.00001
0.000001
Cs-137 Ra-226+D
Tc-99
Pu-239
U-238+D
Th-232
Rural D Rural+Ag D Int D Int+Ag D Suburban
-------
4. Development of Reference Sites
As stated in the introduction, technical support for the development of the cleanup regulation
must produce comprehensive information on the potential health and economic impacts of the
rule, including estimates of:
The volume of soil requiring remediation to achieve alternative risk-based cleanup
levels; and
• The number of adverse radiological health effects both averted and caused by site
cleanup to the alternative cleanup levels.
Chapter 5 of this report estimates the volume of soil that would require remediation, and the
number of health effects averted and caused by remediation, if the cleanup level were set at
various individual-risk levels, e.g., IxlO"3, IxlO"4, etc. These estimates require, and are based on,
an understanding of the nature and extent of the contamination at the various sites that may fall
within the scope of the rule.
It is not feasible to obtain sufficient data to characterize each site covered by the rule. There are
thousands of diverse sites, many of which have highly complex source terms. The complete
characterization of an individual site often requires a large array of environmental parameters as
well as detailed demographic data. Furthermore, detailed site characterization data simply does
not exist for most of these sites. Therefore, a set of conceptual reference sites—based largely,
but not totally, on data collected at one or more actual sites—was developed to represent the
universe of actual contaminated sites. An assessment was made of the public health impacts of
remediating various quantities of contaminated soil at each of these reference sites. These
analyses, together with an estimate of the number of real sites represented by each reference site,
enable an assessment of the total health impacts on society of remediating all real sites subject
to the rule to various levels of cleanup. They also play an integral role in the assessment of the
economic costs of such cleanup. This chapter describes the methodology and assumptions
underlying the creation of the 16 reference sites.
The reference sites are only partially based on data from real sites, and cannot be taken as
complete and accurate characterizations of those sites. For instance, the present analysis requires
that concentrations of contaminants in the soil be described as continuous functions of the volume
of soil contaminated at or above a given concentration. Such data is extremely sparse.
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Constructing contaminant distribution functions for the reference sites therefore necessitated
interpolating between the few available data points, often extrapolating beyond their range, and
sometimes using data from other actual sites or forming a synthesis of several actual sites.
Limitations of the models employed and other constraints on the scope of the analyses required
that the reference sites be simplified idealizations of the actual sites. For instance, the
contamination at the reference sites is assumed to start at the surface, to be uniform in the vertical
direction, and to end abruptly at some depth that is constant over the entire site or sub-site. In
addition, current- and future-use scenarios and exposure pathways at the reference sites employ
a number of default assumptions and parameters that do not apply to the actual sites. Finally,
many parameters characterizing the actual sites have either not been measured or are beyond the
capability of the models used for this analysis.
Thus, it would be inappropriate to assume that any reference site provides an accurate description
of the actual site or sites upon which it was based. At the same time, the set of reference sites,
taken as a whole, is intended to capture the range of conditions to be found throughout the
universe of actual sites. Thus, an assessment of the public health benefits of cleaning up these
sites (incorporating a wide range of current and future exposure scenarios) as well as an analysis
of the volumes of soil that must be remediated, supports the cleanup rulemaking.
EPA employed a three-step process in constructing the reference sites. First, the Agency
collected and reviewed data on the more than three hundred sites and sub-sites (i.e., OU's,
WAG's, etc.) for which formal RI/FS and other characterization documents are available. From
these, EPA selected the subset of sites for which there was sufficient information to allow (with
only limited use of default assumptions and parameters) an analysis of health impacts and
volumes of soil requiring remediation. That subset represents fairly well the real sites (including
some of those believed to contain most of the contaminated soil) that fall within the scope of the
rulemaking. The third step consisted of employing the data on the selected subset of sites, along
with a limited amount of input information that is not site-specific, to construct the reference
sites.
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The present analysis is limited to radioactivity in soil, and does not include radioactive wastes
contained in storage areas or burial grounds. It is assumed that these sources of radioactive waste
will be excavated and properly disposed of or stabilized in place—such waste falls into the
category of conventional low-level waste and will be managed according to existing NRC (10
CFR 61) and DOE (10 CFR 834) regulations and pending EPA regulations. Accordingly, site
characterization was limited to the evaluation of sites/sub-sites where the soil was contaminated
as a result of spills, leaks, local fallout, overflow contamination or runoff from nearby sources
of radioactive waste, or by windblown depositions.
The analysis of the benefits of remediating the reference sites to different levels of cleanup, and
the determination of the volumes of soil that must be remediated to achieve these cleanup levels,
are discussed in Chapter 5. The results of the analyses are then extrapolated to the universe of
all radioactively contaminated sites covered by the rule,
4.1 GATHERING THE DATA ON REPRESENTATIVE SITES
EPA has analyzed available published data on more than three hundred sites, representing a wide
range of administrative and functional categories and possessing a broad cross-section of source
term and environmental characteristics. The process of identifying and obtaining data that could
contribute to the process of constructing reference sites proceeded in an iterative manner. It
began with the development of a list of key parameters needed to adequately characterize sites.
These included the list of radioactive contaminants, the volumes of soil containing different
concentrations of contaminants, and the hydrogeological and meteorological characteristics of
the sites/sub-sites.
These parameters were initially used to conduct a pilot survey of 20 sites/sub-sites, with the
intention of assessing the feasibility of extracting the necessary data from existing documentation,
such as Remedial Investigation and Feasibility Study (RI/FS) reports. The pilot survey showed
that data for many of the key parameters were not readily available. It suggested, however, that
an expansion of this effort, with a more thorough and sophisticated analysis of published
documents, might meet the needs of the rulemaking process. It was apparent, moreover, that
more active assistance of DOE, DOD, and NRC in obtaining site characterization data would be
extremely helpful.
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The remainder of this chapter discusses the collection of data, primarily from published
documents describing actual sites, and the creation of reference sites based on these data. It is
anticipated that data provided by DOE, DOD, and NRC in the future will support the results of
analyses based on the data that is currently available.
4.1.1 Sources of Data on DOE. DOD. and NRC Sites
Data on DOE nuclear facilities, which were the primary focus of the first phase of data collection,
were obtained from DOE Public Reading Rooms and libraries and from EPA Regional Offices.
Document review began with the acquisition of Federal Facility Agreements for each DOE
facility, which identify the waste management units at each site/sub-site and the status of the
remedial investigation, and also indicate what reports are available concerning a site/sub-site.
Where available, Records of Decisions (RODs), Baseline Risk Assessments and RI/FS reports
were obtained. For sites/sub-sites where RODs and RI/FS materials had not yet been completed,
an attempt was made to obtain Preliminary Assessment/Site Investigation (PA/SI) reports,
Environmental Audit Reports, Environmental Assessment Reports, Environmental Monitoring
Reports, Environmental Data Packages, and Effluent Reports. Data on the volumes of
contaminated soil at major DOE sites were supplemented by DOE's Integrated Data Base (DOE
94b).
Data on DOD sites were obtained from comparable sources.
Data characterizing NRC-licensed facilities were obtained from available documentation on the
NRC's Sites Decommissioning Management Program (SDMP) and documents relating to the
decommissioning of individual facilities and remediation of the sites. The latter were obtained
from NRC's Public Document Room. Sites representing four of the generic categories modeled
in the NRC's Generic Environmental Impact Statement (GEIS) were used in the study, including
two of the same facilities cited in the GEIS.
Useful information was also obtained from databases of the Soil Conservation Service
(Department of Agriculture), the US Geologic Survey (Department of Interior), the National
Oceanic and Atmospheric Administration (Department of Commerce), and the Bureau of the
Census (DOC).
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4.1.2 Site Categorization Scheme
It became apparent early in the study that the appropriate role of the reference sites would be to
mimic the conditions at facilities that performed different tasks. The universe of real sites was
therefore divided into categories along functional lines, beginning with facilities that were part
of the nuclear fuel cycle and those involved in the production of nuclear weapons. Additional
categories were created to encompass other activities in which soils might be contaminated with
radioactivity. The list of functional categories and sub-categories depicted in Table 4-1 was
developed by a Federal agency workgroup consisting of representatives of EPA, DOE, NRC and
DOD (Army, Navy, and Air Force). These categories reflect a wide range of radionuclide
concentrations, chemical and physical forms of contaminants, spatial distributions (depths and
areas) of contamination, and other source characteristics encountered in practice. Table 4-1 also
presents the administrative authorities responsible for each category of site.
Not all functional and administrative categories are explicitly represented with reference sites
because:
• Several functional categories, such as Categories 8, 10, and 11 (Sealed Source
Users, Accelerators, and Fusion Facilities), do not have significant soil
contamination.
• Several functional categories can be represented by other categories. For
example, Category 6 (Research/ Biomedical/Analytical Laboratories) can
represent Categories 8 and 9 (Sealed Source Users and Nuclear Medicine
Departments).
Table 4-1 includes a Category 18 representing the large, multi-functional DOE facilities which
encompass many of the other functional categories described in the table.
Though not every functional and administrative category has been captured by the set of
reference sites, abroad range of categories are represented, and most of the contaminated soil in
the United States (not including diffuse NORM) is represented by them.
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Table 4-1. Site Categories Characterized by the Survey
FUNCTIONAL CATEGORIES
1
2
3
4
5
6
MINES AND MILLS
CONVERSION/ENRICHMENT
FUEL FABRICATION/
WEAPONS ASSEMBLY
REPROCESSING/EXTRACTION
REACTORS
RESEARCH/BIOMEDICAL/
ANALYTICAL LABS
SUB-
CATEGORY
Mines
Mills
Rare Metal
Extraction
UF6 Conversion
Gaseous
Diffusion
Commercial Fuel
Fabrication
Weapons
Fuel/Target
Fabrication
Weapons Parts
Production/
Assembly
Commercial
Weapons
Commercial
Power
DOE
Research/Test
Commercial
Research/Test
Weapons
Production
Isotope
Production
DOE National
Laboratories
NRC Licensed/
Other
Government
Academic
ADMINISTRATIVE AUTHORITIES
DOE
/
//
//
//
//
//
//
//
/
//
/
DOD
/
/
NRC
LICENSEES
//
//
//
/
//
//
/
//
/
EPA
NON-FEDERAL
NPL SITES
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4-6
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Table 4-1. (continued)
FUNCTIONAL CATEGORIES
7
8
9
10
11
12
13
14
15
16
17
INDUSTRIAL/COMMERCIAL
(Non-Sealed Sources)
SEALED SOURCE USERS
NUCLEAR MEDICINE
DEPARTMENTS
ACCELERATORS
FUSION FACILITIES
NUCLEAR TEST SITES
WEAPONS ACCIDENTS AND
SAFETY TESTS
DEPLETED URANIUM
OTHER DOD FACILITIES
WASTE DISPOSAL
NATURALLY OCCURRING
RADIOACTIVE WASTES
SUB-
CATEGORY
Radiochemical/
Radioanalytical
Sealed Source
Manufacturing
Industrial
Accidents
DOD Test Ranges
DU Storage
Air Force Bases
Army Bases
Marine Bases
National Guard
Naval Shipyard/
Air Stations
Incinerators
Municipal
Landfills
Commercial
LLRW Sites
Radium Sites
Thorium Sites
Uranium Sites
ADMINISTRATIVE AUTHORITIES
DOE
/
/
/
/
/
/
/
//
/
/
/
//
//
//
DOD
/
/
/
/
/
/
//
/
/
/
/
/
/
/
/
NRC
LICENSEES
//
//
/
/
/
/
EPA
NON-FEDERAL
NPL SITES
/
/
/
/
/
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4-7
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Table 4-1. (continued)
FUNCTIONAL CATEGORIES
18
ENTIRE FACILITY
SUB-
CATEGORY
Hanford
Reservation
Savannah River
Site
Idaho National
Engineering
Laboratory
Oak Ridge
Reservation
Aberdeen Proving
Ground
Fernald
Mound
Nevada Test Site
Paducah Gaseous
Diffusion Plant
Pantex
Portsmouth
Gaseous
Diffusion Plant
Rocky Flats
Weldon Spring
ADMINISTRATIVE AUTHORITIES
DOE
//
//
//
//
//
//
//
//
/
/
//
//
DOD
//
NRC
LICENSEES
EPA
NON-FEDERAL
NPL SITES
(a) A single check (/) indicates that such facilities exist for the indicated administrative authority. Subcategories with double checks^/)
are represented by reference sites.
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4-8
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4.1.3 Aerial Surveys
Aerial radiological surveys, which have been conducted over major DOE facilities, commercial
nuclear power plants, and other large sites, provide an important source of data on radionuclide
contamination of the soil. To supplement the site information obtained from RI/FS and other
documents, a set of 61 aerial radiological survey reports were examined to identify the
radionuclides in the soil and to determine the area on each site with a given level of
contamination based on the activity concentration1 of a given radionuclide (e.g., <1, 1-10, 10-
100, 100-1,000, >1,000 pCi/g).
The aerial surveys were conducted by EG&G Energy Measurements, typically using a helicopter
outfitted with an array of 20 Nal(Tl) detectors. A flight pattern was flown over the survey area
at a usual altitude of 46 m, with flight lines spaced 76 m apart. The raw data consists of geo-
referenced gamma spectra recorded every 100 feet (30 m) of flight path.
The only quantity actually measured by a survey was the g-ray flux rate as a function of photon
energy. The cosmic ray contribution to the spectra can be estimated on the basis of global data.
The radionuclides contributing to these radiation fields could be distinguished from other nuclides
likely to be found at a given site by the shape of the spectra. Other quantities can only be inferred
from the data, based on assumptions regarding their distribution in the soil. For example, given
the aircraft's altitude, it is possible to calculate the spectrum that would be generated by soil with
a uniform contamination of 1 pCi/g of Cs-137—contamination having an infinite area and depth.
Then, for a given spectrum that includes the Cs-137 photopeak, one can calculate the soil
concentration of Cs-137 giving rise to such a spectrum, assuming that the contamination is in fact
uniform in all three dimensions (within the field of view of the detectors and within the depth of
penetration of the Cs-137 g-ray s). If, instead, it is assumed that the contamination consists of a
very thin layer deposited on the surface, a very different concentration and a vastly different
inventory would be calculated. Calculations of exposure rates at an altitude of 1 m above the
surface and of annual dose rates to an individual at ground level are based on similar types of
assumptions.
1 Although this report, to be consistent with the literature on soil contamination, usually quantifies the
contamination as "activity concentration" or "radionuclide concentration in the soil" in units of pCi/g, the
technically correct term is the specific activity of a given nuclide. The expressions are used interchangeably.
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The aerial survey reports included maps consisting of isopleths delineating radiation fields of
different intensities superimposed on aerial photographs of the surveyed areas. The radiation
fields were represented by one or more of the following quantities:
count rate (cps)
• exposure rate (|iR/hr)
annual dose rate (mrem/yr)
• surface concentration (nCi/m2)
specific activity (pCi/g)
The radiation fields were based on one of the following sources:
• total gamma
terrestrial gamma (excluding cosmic rays)
• man-made gamma (excluding cosmic rays and naturally-occurring background
terrestrial radionuclides)
• specific radionuclide
To enable the calculation of radionuclide concentrations as a function of volume, one or more
of the following were needed:
specific activities of individual nuclides (pCi/g)
• surface activities of individual nuclides (nCi/m2)
count rates or calculated exposure rates or dose rates from specific radionuclides
accompanied by conversion factors for calculating specific activities
In addition, vertical concentration profiles or defensible assumptions regarding the depth
distributions are required.
Only 14 of the reports, which presented data on 10 different facilities and included a total of 30
maps, contained the minimum information necessary to determine the radionuclide distributions
in the soil. A list of these reports can be found in Appendix J.
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Only in the few cases (comprising 6 maps) that specific activity isopleths (pCi/g) were presented,
no conversions were required. In the case of surface activity isopleths (nCi/m2), a conversion was
made assuming a bulk soil density of 1.5 g/cm3 (in common with most of the EG&G reports) and
a uniform radionuclide distribution to a depth of 5 cm.2
For maps not showing either specific or surface activities, a conversion was possible only in the
cases where the isopleths were for an identified, specific radionuclide. This is because the
particular radionuclide conversion factors published in the reports are for a specific energy
window centered on the relevant photopeak and can only be used for data produced from that
particular energy window. Generally, only one conversion factor (pCi/g per cps) is presented in
the reports for each radionuclide, although in some cases a number of values are presented for
various relaxation lengths.3
The procedure for producing the area vs. activity histograms for maps that allow such calculations
was as follows:
Step 1: Determine which maps are suitable. The maps must contain either activity
concentration data or specific photopeak data with conversions to activity concentration
presented in report.
2 The model used for analyzing the soil cleanup at the reference sites requires a uniform, finite depth o f
contamination. The EG&G reports generally do not cite such a depth—at most a relaxation depth is cited
(see note 3). 5 cm was chosen as a reasonable compromise between a very deep and a very shallow
contaminated layer. A more thorough discussion of this assumption can be found under the description of
soil contamination at Reference Site I in Section 4.4.3.
3 The following exponential expression is commonly used in the EG&G reports to characterize the vertical
contamination profile:
C = C0e^
C = concentration at depth y
C0 = concentration at surface
1 = relaxation length
y = depth
The relaxation length is defined by the above expression. An alternate definition that applies in the present
context: the increment of depth over which the concentration is reduced by a factor of 1/e.
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Step 2: Determine which isopleths are of interest. The activity concentration intervals
desired were <1, 1-10, 10-100, 100-1,000, >1,000 pCi/g. This step requires the listed data
to be converted to activity concentration for most of the maps used. Isopleths closest to
the above concentrations were selected from each map.
Step 3) Overlay map and trace relevant information by hand. A sheet of quadrille paper
(10 squares per inch) was taped to the map. The pair was placed on a light table and the
relevant isopleths, map scale and survey boundary were traced.
Step 4) Count grid elements bounded by isopleths. After tracing, the quadrille paper was
removed from the light table and the grid elements between isopleths were counted.
Step 5) Determine area conversion. The scale from the map was compared to the grid
elements to produce a conversion (m2/grid element).
Step 6) Calculate areas. The number of grid elements in each activity concentration
interval was multiplied by the area per grid element to produce an area for each activity
concentration interval.
Step 7) Sum results for sites with multiple maps. Some of the larger sites required the use
of multiple maps and multiple reports. For these sites, the distribution from each map was
copied to a site summary and summed for a site total. Additional information that pertains
to all maps is also recorded on the site summary.
Sources of Error
Three types of errors are inherent in the use of the aerial survey data to characterize soil
contamination: errors stemming from interpretation of the data, errors stemming from possible
inadequacies of the data, and errors from the graphical method used to evaluate the data.
Errors in interpreting the data. A main source of error in the above procedure stems from the
assumptions regarding the depth profile of the contamination. For Cs-137, the principal nuclide
modeled on the basis of the aerial survey data, the dose rate from direct radiation to an individual
at ground level increases by less than a factor of 2 if the thickness of the contaminated zone is
increased from 5 cm to infinity. Conversely, it decreases by less than a factor of 3 if the thickness
is decreased from 5 cm to 1 cm—an improbably low value for sites where the contamination has
had time to "weather in" (i.e., disperse downwards in the soil as a result of rainfall and wind).
Thus, 5 cm is a reasonable compromise in the absence of soil sampling data, which were not
available for many sites.
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Another source of error stemmed from the possible misidentification of other radiation sources
(e.g., reactor buildings, waste storage tanks, and radioactive wastes in above- or below-ground
waste storage facilities) as contaminated soils. The detectors are not collimated; their wide field
of view causes them to report what are essentially point sources as series of concentric circles.4
Except as noted in the descriptions of the soil contamination at the individual reference sites
which appear in Section 4.4.3, it was assumed at this initial stage of the data collection that all
radiation fields were due to contaminated soils. This conservative assumption could result in the
overestimation of soil volumes and, because the radiation fields generated by the facilities tend
to be much more intense than those resulting from soil contamination, an even greater
overestimation of the radionuclide inventories in the contaminated soils.
Errors based on possibly incomplete data. It is not clear that all contaminated areas are
accounted for at each site. For example, the Nevada Test Site has a number of areas that are
surveyed in reports that were not readily available.
Accuracy of the graphical method. An additional source of error stemmed from miscounting grid
elements, primarily from deciding whether or not to include squares intersected by isopleths.
Since the smallest grid square was 0.1" wide, some small areas on the maps, which were of
comparable size, may be misestimated. The significance of this error diminishes for larger map
areas. The establishment of a conversion factor from the map scale was another source of error.
Other errors may have been introduced while tracing the isopleths and reproducing the maps.
4.2 SELECTION OF BASIS SITES
The actual sites that were to form the bases of the reference sites were selected by comparing the
site categorization scheme and additional site selection criteria with Federal facility site
description documents and the available aerial survey data. The process, which was later
augmented by an additional data search, resulted in the development of 16 reference sites.
4 The most intense radiation field is directly over the source. As the aircraft flies further away, the fiel d
becomes weaker, resulting in a lower count rate. Thus, a point source will be mapped as a diffuse, circular
radioactive area with axial symmetry.
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4.2.1 Site Selection Criteria
Table 4-2 presents the criteria for selecting each actual site or sites which form the basis of each
of the reference sites. These sites are referred to as "basis sites." These criteria were selected to
ensure that the reference sites encompass the full range of sites that may fall within the scope of
this rule.
Criteria 1 and 2 ensure that the reference sites reflect the principal administrative and functional
categories being administered under the major site cleanup programs. Sites are defined in terms
of their administrative and functional categories. As such, the adequacy of the reference sites is
judged by the degree to which the different administrative and functional categories are
represented.
Criterion 3 is designed to assure that the major DOE facilities are represented. As indicated
earlier, the DOE Environmental Restoration (ER) program is perhaps the single largest source
of contaminated soil (not including NORM). Accordingly, the major DOE facilities with soil
contamination must be represented.
Criterion 4 provides a level of assurance that a full range of source characteristics (i.e.,
radionuclides, radionuclide distributions, and areas, volumes and thicknesses of contaminated
soil) are represented. Ideally, the reference sites should be generally representative of the source
characteristics for the full range of administrative and functional categories.
Criterion 5 provides a level of assurance that a full range of environmental and demographic
settings are represented. It is not sufficient to ensure that a full range of source characteristics is
represented. The same source characteristics in a different environmental and demographic
setting could pose substantially different risks. (As will be discussed subsequently, for five of
the reference sites, three different environmental settings were chosen for each. This, in effect,
expands the total number of distinct reference sites to 26.)
Table 4-3 describes the basis sites that were selected according to the criteria of Table 4-2.
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Table 4-2. Criteria for the Selection/Construction of Reference Sites Required to
Support the Soil Cleanup Rule
1. REPRESENTATIVE OF THE MAJOR ADMINISTRATIVE CATEGORIES OF SITES
• DOE Facilities
• NRC Licensees
DOD Facilities
2. REPRESENTATIVE OF THE MAJOR FUNCTIONAL CATEGORIES OF SITES
• Weapons Production and R&D Facilities
• Fuel Cycle Facilities
• Materials Licensees
3. MAJOR FACILITIES THAT ARE UNIQUE
• Hanford
• Savannah River
Oak Ridge
Etc.
4. REPRESENTATIVE OF THE RANGE OF SOURCE CHARACTERISTICS
• Radionuclides
• Concentrations
• Depth and Area of Contamination
• Chemical and Physical Form
5. REPRESENTATIVE OF A RANGE OF ENVIRONMENTAL SETTINGS
• Climatology
• Hydrogeology
• Demography
• Soil Characteristics
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Table 4-3. REFERENCE SITES
Ref.
Site
I
II
III
IV
V
VI
VII
IX
X
XXII
Site Description
MAJOR DOE FACILITIES:
Very Large Multi-Functional
Fuel Reprocessing and Weapons
Material Production Facility
Medium-Size Nuclear Materials
Production Facility
Very Large Multi-Functional
Fuel Processing and Enrichment
Facility
Small Fuel Processing Facility
Very Large Multi-Functional
Nuclear Materials Production
Facility
Large Multi-Functional Weapons
Production and Research Facility
Very Large Nuclear Testing
Facility
Medium-Size Fuel Fabrication
Plant
Medium-Size Gaseous Diffusion
Plant
Small FUSRAP Facility
Name of Basis Site
Hanford Reservation
Fernald
Environmental
Management Project
Idaho National
Engineering
Laboratory
Weldon Spring
Savannah River Site
Oak Ridge
Reservation
Nevada Test Site
Rocky Flats Plant
Paducah Gaseous
Diffusion Plant
Maywood Chemical
Co.
Contaminants
of Concern
Cs-137
Ra, Th, U
Cs-137
U
Cs-137
Cs-137, U
Cs-137, Pu,
Am-241
Pu, Am-241
U, Tc-99
Ra, Th, U
Weather/
Rainfall
And
High Rainfall
Dry
Moderately
High Rainfall
High Rainfall
High Rainfall
And
Modest
Rainfall
High Rainfall
Moderately
High Rainfall
Aquifer
Deep
Moderately
Deep
Deep
Shallow
Moderate
Depth
Moderate
Depth
Deep
Relatively
Shallow
Relatively
Shallow
Moderately
Shallow
Population
Density" (km'2)
100
1000
100
200
100
300
10
200
100
1400
Weighting
Factorb
1
1
1
1
1
22.7
1
1
1.1
6.9
-------
Table 4-3. (continued)
Ref.
Site
XII
XIII
XVI
XVII
I
XX
XXI
Site Description
Name of Basis Site
Contaminants
of Concern
Weather/
Rainfall
SELECTED DOD FACILITIES
Weapons Accident Site
Depleted Uranium Site
BOMARC missile
accident site
Aberdeen Proving
Ground
Pu-239,
Am-241
Depleted U
Moderately
High Rainfall
3 Environmental
Aquifer
Population
Density" (km'2)
Weighting
Factorb
Moderately
Shallow
Settings0
1000
200
1
8.5d
SELECTED NRC REFERENCE SITES:
Light Water Reactor
Research Reactor
Generic Fuel Fabrication Facility
Rare Earth Extraction Plant
e
Cintichem, Inc.
B&W Plant, Apollo,
PA
Molycorp Plant,
Washington, PA
Cs-137, Co-60
Cs-137, Sr-90
Uranium
Thorium
3 Environmental
3 Environmental
3 Environmental
3 Environmental
Settings0
Settings0
Settings0
Settings0
200
1000
200
1000
125d
63d
14d
22d
a Reasonable occupancy scenario—see Section 5.2 and App. D
b Discussed in Section 4.3.
c The three environmental settings are discussed in Section 4.4.1
d Sum of weighting factors for sites in three different settings
e Based on composite data from six commercial nuclear power plants
-------
The sites are grouped into the major administrative categories in an effort to satisfy Criterion 1.
The major Federal facilities include 10 major DOE facilities, which represent most of the
contaminated soil and the full range of functional categories in the DOE ER program, thereby
satisfying Criterion 3. Detailed descriptions of the basis for each reference site and the assumed
characteristics of each site are present below.
The two DOD facilities represent two of the major DOD functional categories: weapons accident
sites and depleted uranium test ranges. Other DOD sites, such as reactors and byproduct
materials licensees, are represented by the sites listed under NRC licensees. The four NRC sites
represent the various types of NRC licensees, including commercial, test and research reactors,
fuel cycle facilities, broad materials licensees (medical and industrial), and rare earth extraction
facilities.
4.3 REFERENCE SITE WEIGHTING FACTORS
The total volume of radioactively contaminated soil in the U.S. is not known with any degree of
certainty. Indeed, it probably will not be known until cleanup criteria are defined and the sites
are remediated or at least assessed comprehensively.
In order to estimate the total radioactively-contaminated soil volume generated by the 4,952 sites
identified in Table 1-1, a set of weighting factors has been developed for the 16 reference sites.
The soil volume at each reference site is multiplied by the corresponding weighting factor; the
sum of the weighted volumes serves as an estimate of the total soil volume.
Following a review of the available soil volume data in DOE's 1993 Integrated Data Base (IDE),
a weighting factor of 1 was assigned to each of the seven large multi-functional reference sites:
those based on Fernald, Hanford, Idaho, Nevada Test Site, Rocky Flats, Savannah River, and
Weldon Spring. This means that each of these reference sites represents only one real site in the
universe of sites.
The remaining three DOE sites that serve as basis sites are Paducah, Oak Ridge Reservation, and
Maywood. The Paducah site is a Gaseous Diffusion Plant, similar to the Portsmouth site.
Therefore, Reference Site X is used to represent both Paducah and Portsmouth.5 The weighting
5 The detailed description of the 16 reference sites is presented in Section 4.4.3.
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factor for this reference site is calculated by dividing the sum of the IDE soil volumes for the two
basis sites by the Paducah soil volume—the resulting factor is equal to 1.1.
The IDE lists significant volumes of radioactively-contaminated soil at Mound, Argonne,
Brookhaven, Los Alamos, and Sandia. These five DOE facilities are involved with diversified
weapons research and development activities. However, the available data was not sufficient to
enable these sites to serve as the bases for constructing reference sites. The Oak Ridge
Reservation (ORR) is involved in diversified weapons research and fuel production activities;
ORR was therefore selected to represent itself as well as the other five sites in the present
analysis. The weighting factor is calculated by dividing the sum of IDE soil volumes of all six
sites by the ORR soil volume, which yields a factor of 22.7.
There are 30 FUSRAP sites identified in Table 1-1, including the May wood site. Even though
there may be significant difference among these sites, Reference Site XXII, based on the well-
characterized Maywood site, was used to represent all 30 sites in the present analysis. There is
no separate site-by-site soil volume presented in the IDE for each of the 30 FUSRAP sites.
However, the IDE provides the following soil volume data:
Missouri sites (4) 7.2xl05 m3
New Jersey sites (5) 4.6xl05
New York sites (7) 4.8xl05
Other sites (14) 1.3xl05
Total 1.8xl06m3
An estimated contaminated soil volume for the Maywood site of 2.6xl05 m3 is listed in an EPA
report (EPA 93b). Dividing the total IDB FUSRAP soil volume by the Maywood volume yields
a weighting factor of 6.9 for Reference Site XXII.
Only one nuclear accident site, BOMARC, was identified by the site survey. It therefore
constitutes a unique basis site and was assigned a weighting factor of 1.
There are a total of 16 sites contaminated with depleted uranium (DU), including the large, multi-
functional Aberdeen Proving Ground (APG). These sites are listed below.
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Aberdeen Proving Ground Basis site
Eglin Air Force Base Major site
Camp Roberts Major site
Green River Test Site Small site
Jefferson Proving Ground Major site
Joliet Army Ammunition Plant Research site
Lake City Army Ammunition Major site
Materials Technology Lab Research site
Picatinny Arsenal Small site
Twin Cities Army Ammunition Research site
Lexington Arsenal Major site
Watervliet Arsenal Research site
White Sands Missile Range Major site
Yuma Proving Ground Major site
Dahlgren Naval Surface Weapons Center Small site
El Toro Marine Corps Air Station Small site
Among these 16 sites, there are eight major testing ranges, four small munitions firing ranges,
and four small research and processing sites. APG is the basis for Reference Site XIII, which
represents all the DU sites. The seven other major DU sites were each given a weighting factor
of 1, the same as that of Aberdeen. Available documentation on Dahlgren NSWC suggested a
weighting factor of 0.12, relative to that of Aberdeen, for each of the four smaller munitions
firing ranges. Similarly, available information on the Materials Technology Lab led to the choice
of a weighting factor of nearly zero for the four small research and processing sites. The total
weighting factor for this category is therefore 8.5.
The weighting factors for NRC sites are based entirely on values presented in the NRC's Draft
Generic Environmental Impact Statement (NRC 94). The actual site counts given by NRC are
used as the weighting factors, i.e., 125 for nuclear power plants, 63 for test and research reactors,
14 for fuel fabrication plants, and 22 for rare earth extraction facilities. The 49 uranium mills
under the "other fuel cycle facilities" category are covered under 40 CFR Part 192 and are not
within the scope of the present report.
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4.4 CONSTRUCTION OF REFERENCE SITES
4.4.1 Parameters Used in Risk and Dose Assessments
DRASTIC parameters. The environmental characteristics of the reference sites capture a broad
range of settings. All ten of the DOE-based reference sites and one of the DOD sites (based on
BOM ARC) are unique facilities and are therefore postulated to have environmental
characteristics that reflect those of their basis sites. The four sites based on NRC-licensed
facilities and the remaining DOD-based site are more generalized reference sites, each of which
is postulated to reflect soil conditions at a number of locations throughout the United States.
Each of these five references sites are therefore postulated to be located in any of three alternative
environmental settings—settings chosen to represent the diverse environments where many of
the corresponding actual facilities are found. Thus, Reference Site XIII consists of Reference
Sites XIIIA, XIIIB and XIIIC, similarly for Reference Sites XVI- XXI. The three sets of site
environmental characteristics that describe these settings were chosen on the basis of the
DRASTIC standardized system for evaluating groundwater pollution potential (EPA 85a) of
various hydrogeologic settings. This system is based on the results of an EPA investigation,
which found that the most important mappable factors that control the groundwater pollution
potential were:
- Depth to water
- Recharge (net)
- Aquifer media (soil type)
- Soil media (unsaturated zone)
- Topography (slope)
- Impact of the vadose zone media
- Conductivity (hydraulic) of the aquifer
Tables in the DRASTIC manual provide ranges and respective rankings for each of the site
characteristics listed above. For example, Table 4 in the manual provides ranges for the depth
to water (e.g., 0-5 ft, 5-10 ft, etc.) and also assigns a number from 1 to 10 to each of the depth
ranges. The higher the ranking number, the greater the potential that the corresponding depth to
the water would potentially result in groundwater contamination.
The ranges of parameter values defined in the DRASTIC manual were used in constructing the
basic framework of the Reference Sites -A, -B and -C. Specifically, for Reference Sites -A,
parameter values were selected that would result in a low potential for groundwater
contamination; for Reference Sites -B, parameter values were selected that would result in a
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moderate potential for groundwater contamination; and for Reference Sites -C, parameter values
were selected that would result in a high potential for groundwater contamination.
The site characteristics which were extracted from the DRASTIC manual for use in the modeling
include: soil types for the unsaturated and saturated zones (identified in DRASTIC as "soil" and
"aquifer" media); unsaturated zone thickness (equivalent to "depth to water"); infiltration rate
(equivalent to "net recharge"); and, indirectly, land surface topography.
The land surface topography was translated to a water-table hydraulic gradient based on the
assumption that the shallow water table roughly follows the land surface.6 Table 4-4 identifies
the ranges of values selected for each of the three environmental settings.
Table 4-4. Range of Parameter Values for Site Types A, B, and C
Environmental
Setting
Site Type A
Site Type B
Site Type C
Parameter
Depth to
Water
Table (feet)
>50
10-50
< 10
Net
Recharge
(inches/yr)
<3
3 -7
>7
Aquifer
Media
Shale/
Metamorphi
c/ Igneous
Sandstone/
Limestone
Sand and
gravel/
Basalt/ Karst
limestone
Soil Media
Non-
shrinking,
non-
aggregated
clay/ Clay
loam
Loam/Sandy
Loam/
Shrinking
and/or
Aggregated
Clay
Sand/
Gravel/
Thin or
absent
Topography
> 12% slope
6 - 12%
slope
< 6% slope
Hydraulic
Conductivity
(m/y)
<750
750- 1500
> 1500
6 This assumption is consistent with the overall logic behind the construction of the three environmenta 1
settings in that, as the gradient decreases, the amount of dilution also decreases. Therefore, the potential for
higher concentrations of contaminants in groundwater would be reflected by a lower gradient.
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The vadose zone is synonymous to the unsaturated zone and is defined as that zone above the
water table that is unsaturated. The type of vadose zone media determines the attenuation
characteristics of the material below the typical soil horizon and above the water table.
Biodegradation, neutralization, mechanical filtration, chemical reaction, volatilization, and
dispersion are all processes which may occur within the vadose zone. DRASTIC designates
vadose zone media by descriptive names (e.g., silt, sandstone, gravel) and ranks each medium
relative to its pollution potential. The impact of the vadose zone ranking is essentially the same
as the soil media ranking. That is, silt/clay is the lowest on both scales while gravel presented
the highest groundwater pollution potential. To avoid repetition, vadose zone impact criteria
were not included in the generic site analysis.
The soil and rock type information that was obtained from DRASTIC is qualitative. Therefore,
it was necessary to obtain independent estimates of hydraulic properties in order to provide more
quantitative input into the risk assessment models. Almost all of these additional estimates were
made using the RESRAD reference table values, with the exception of the saturated zone aquifer
properties. RESRAD does not provide default values for these rock types. Therefore, hydraulic
conductivity values were estimated from DRASTIC Table 12, which was originally presented in
Freeze and Cherry (Fr 79). The hydraulic conductivities assigned to the rock types from Table
12 assume fracture permeabilities.
The soil-specific exponential b (beta) parameter is one of the parameters used to calculate the
radionuclide leaching rate of the contaminated zone. The beta value is an empirical and
dimensionless parameter that is used to evaluate the saturation ratio (or the volumetric water
saturation) of the soil, according to a soil characteristic function called the conductivity function
(i.e., the relationship between the unsaturated hydraulic conductivity and the saturation ratio).
Reasonable estimates based on professional judgment were made for the porosity and beta
parameters of the saturated zone materials. All of the saturated zone rock types were assigned
the same porosity and beta values because of the high degree of uncertainty associated with these
parameters in fractured rocks.
Table 4-5 identifies the selected parameter values for Site Types A, B and C based on the sources
cited above.
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Table 4-5. Selected Parameter Values for Site Types A, B, and C
Environmental
Setting
Site Type A
Site Type B
Site Type C
Contaminated and Unsaturated Zone
Soil Type
Silty Clay
Loam/Sandy
Loam/Shrinking
Aggregated Clay
Sand/Gravel/
Thin or Absent
Unsat.
Zone
Thickness (m)
45.7
15.2
3.05
Hydraulic
Conductivity
(Ksat:m/yr)
32.6
1090
4460
beta
10.4
4.9
4.05
Total
Porosity
(ThetO
0.492
0.435
0.395
Effective
Porosity
Pe
0.2
0.2
0.3
Infiltration
Rate
(m/yr)
7.62E-02
1.78E-01
4.06E-01
Environmental
Setting
Site Type A
Site Type B
Site Type C
Saturated Zone
Soil Type
Shale
Metamorphic
Igneous
Sandstone
Limestone
Sand&
Gravel
Basalt
Karst
Limestone
Conductivity
(Ksqtm/yr)
7.45E+03
1.50E+04
2.23E+04
beta
4.05
4.05
4.05
Total Porosity
(Theta sat)
0.395
0.395
0.395
Effective
Porosity Pe
0.2
0.2
0.2
Gradient
0.12
0.08
0.06
-------
Site-Specific Reference Site Parameters. Tables 4-6 through 4-8 list the contamination-related
parameters for each of the 16 references sites that were used in performing the site-specific risk
assessments. The contaminated area is a parameter that can change with the cleanup level. This
and the other parameters listed are discussed in the detailed description of the reference sites that
is found in Section 4.4.3.
4.4.2 Characterizing the Radionuclide Distributions
The data obtained at each of the basis sites can be expressed in terms of the volume, area, and
depth of contamination, and the pattern of contamination of the radionuclides in the soil. To
perform the analyses described in Chapter 5, it is necessary to characterize the distribution of
radionuclide concentrations in the soil for each of the reference sites. In particular, the soil
volume vs. contaminant concentration relationship for each radionuclide is required. The method
of constructing these distributions from the data for the basis sites is illustrated by the following
example.
Figure 4-2 depicts the distribution of Cs-137 at Reference Site I. This distribution was derived
from a tabulation of soil volumes in successive concentration ranges, which is illustrated in
Figure 4-1. The volumes represented in this histogram were calculated from a report of an aerial
radiological survey of the Hanford Site. (A detailed discussion of aerial surveys was presented
in Section 4.1.3. A discussion of how the survey was used to characterize this reference site is
presented in the description of Reference Site I, which appears in Section 4.4.3. These soil
volumes were added cumulatively from left to right to form the volumes represented by solid
circles in Figure 4-2. The straight lines drawn between the circles represent a set of power
functions (shown as log-log curves) which constitute the functional relationship between the
cumulative soil volume and the concentration.7 This particular functional form was chosen for
these data because the best curve-fit using a simple function (i.e., linear, logarithmic, exponential
or power) to the seven data points was obtained from a power function. Piece-wise distribution
curves were constructed rather than a single simple curve fitted to the available data because the
piece-wise curves honor the known data points while furnishing the best interpolation between
these points.
7 This curve resembles the CCDF used in probabilistic risk assessments, but with significant differences .
Whereas the CCDF plots a probability—by definition, probabilities are normalized— vs. a consequence, this
curve is represented by a plot of the volume, which is not normalized, vs. a physical parameter. The two
functions are constructed by analogous techniques, however.
Review Draft - 9/26/94 4-25 Do Not Cite Or Quote
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Table 4-6. Characteristics of Contamination at Reference Sites"
Reference
Site
I
II-1/II-6
II-7
III
IV
V
VI
VII
IX
X
XII
Contaminated Area
(m2)
2.26E+07
3.96E+06
1.11E+07
1.81E+07
5.90E+05
1.12E+07
6.70E+06
3.70E+08
4.00E+06
8.92E+03
1.90E+04
Chemical
Elements
Cs
Ac
Pa
Pb
Ra
Th
U
Ac
Pa
Pb
Ra
Th
U
Cs
Ac
Pa
Pb
Ra
Th
U
Cs
Cs
Ac
Pa
Pb
Ra
Th
U
Pu
Am
Cs
Pu
Am
Tc
Ac
Pa
Pb
Ra
Th
U
Pu
Am
V b
Kd
280
2400
2700
550
9100
5800
1,600
2400
2700
550
9100
5800
1,600
1,900
794
330
150
165
1500
330
500C
10,000d
2400
2700
550
9100
5800
1,600
550
1,900
280
10,000e
112,000e
0.1
450
550
270
500
3200
35
550
1,900
Contaminated Zone
Thickness (m)
0.05
0.50
0.05
0.05
0.108
0.05
0.05
0.06
0.05
0.305
1.83
0.9
Review Draft - 9/26/94
4-26
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Table 4-6. (continued)
Reference
Site
XIII
XVI
XVIII
XX
XXI
XXII
Contaminated Area
(m2)
4.19E+04
7.00E+03
3.30E+03
2.00E+04
1.38E+04
3.70E+05
Chemical
Elements
Ac
Pa
Pb
Ra
Th
U
Co
Cs
Cs
Sr
Ac
Pa
Pb
Ra
Th
U
Ra
Th
Ac
Pa
Pb
Ra
Th
U
K b
104
182
469
502
21,909
89
447
894
894
21
104
182
469
502
21,909
89
502
21,909
450
550
270
500
3200
35
Contaminated Zone
Thickness (m)
.08
0.15
0.15
1.0/0.36f
2.50
2.0
a Selected values discussed in the text, except where otherwise noted (ANL 93b, DOE 93a).
b RESRAD 5.0 default values based on soil type, DOE 93a, p. 32-8, unless otherwise noted.
c RAE 91, p. 3-63. Original reference is Lo 87.
d ORNL 88.
e Han 80, p. 152.
f See text
Review Draft - 9/26/94
4-27
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Table 4-7. Characteristics of Contaminated and Unsaturated Zones at the Reference Sites"
Reference
Site
1
II-1/II-6
II-7
III
IV
V
VI
VII
IX
X
XII
XXII
Soil Typeb
Sand
Silt/Clay
Silt/Clay
Clay, Silt,
Loam
Clay-like Silt
Silty Clay
Sand
Silty Clay
Silt/Clay
Sandy Loam
Gravel
Sandy Clay
Sandy Silty
Clay
Sand
Sandy Clay
Hydraulic
Conductivity
(Ksat: m/yr)
5,550
32.1
32.1
53.6
0.315
221
32.6
1,090
3.2
0.85e
5,550
68.4
beta0
4.05
10.4
10.4
7.75
10.4
10.4
10.4
4.9
7.12
10.4
4.05
10.4
Total Porosity
(esat/
0.395
0.492
0.492
0.477
0.36
0.459d
0.492
0.435
0.420
0.459d
0.395
0.492
Effective
Porosity:
Pe
0.3
0.2
0.2
0.2
0.2
0.2
0.2
0.3
0.2
0.2
0.32
0.2
Infiltration
Rate
(m/yr)
0.15
0.30
0.30
0.15
0.41
0.30
0.31
0.0
0.15
0.50
0.54
0.40
Unsat.
Zone
Thicknes
s(m)
50
9.5
10.0
100
11.5
9
4
100
2.24
5.1
6.9
1.0
a Values selected from RESRAD 5.0 guidance or default values except where otherwise noted (ANL
93b, DOE 93a). Values for sites XIIIA - XXIC are listed in Table 4-5, above.
b Soil types are discussed in the text.
c Exponential parameter used to calculate saturation
d Average of two closest values based on RESRAD 5.0 guidance.
e DOE 91, p. 3-30.
Review Draft - 9/26/94
4-28
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Table 4-8. Saturated Zone Characteristics at the Reference Sites"
Reference
Site
I
II
III
IV
V
VI
VII
IX
X
XII
XXII
Soil Typeb
Sandy Gravel
Sand/Gravel
Fractured Basalt
Limestone
Silty Sand
Silt & Clay
Course Gravel
Coarse Gravel and
Sand
Sand/Gravel
Loamy Sand
Silty/Sandy Clay
Loam
Hydraulic
Conductivity
(Ksat: m/yr)
5,550
8.2E4
1E3
8.83C
221
11
3E5
3.2
1010
4,930
120
beta
4.05
4.05
4.9
11.4
5.3
10.4
4.9
4.05
4.05
4.38
5.3
Total Porosity
(q.J
0.395
0.395
0.17
0.482
0.485
0.2
0.28
0.28
0.28
0.41
0.2
Effective
Porosity
(Pe)
0.3
0.3
0.17
0.067
0.2
0.0023
0.21
0.21
0.2
0.32
0.2
Gradient0
1E-4
8.7E-4
2E-3
0.019d
1E-4
5E-3
1E-4
1E-4
7.5E-4
2E-3e
0.01
a Values selected from RESRAD 5.0 guidance or default values except where otherwise noted
(ANL 93b, DOE 93 a). Values for sites XIIIA - XXIC are listed in Table 4-5, above.
b Soil types are discussed in the text.
c Conservative estimate based on best professional judgement unless otherwise noted.
d DOE 92b.
e DOE92f, p. 15-2.
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4-29
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Figure 4-1
Reference Site I
Volume of Contaminated Soil
1,000
500
200
J^.
I
o
CO
*
*
100
,-n
50
o o
10
O
o
1.17-5.85
5.85-18.7 18.7-58.5 58.5-102 102-550 550-948
Contaminant Concentration in Soil (pCi/g - including background)
D Cs-137
948-2930
-------
Figure 4-2
Reference Site I
Complementary Cumulative Volume of Contaminated Soil
CO
E
3,000
1,000
300
100
II 30
o
C/}
o
o
O
fit
O
10
2 5 10 20 50 100 200 500
Contaminant Concentration in Soil (pCi/g - including background)
Cs-137
1,000
-------
An important point must be made concerning the data depicted in Figures 4-1 and 4-2. No
volumes are shown for Cs-137 concentrations less than 1.17 pCi/g, which corresponds to the
lowest isopleths on the aerial survey maps for this site. However, the typical concentration of Cs-
137 at the Hanford Site as a result of world-wide fallout is approximately 0.5 pCi/g. The
available data do not indicate the volume of soil that may be contaminated at 0.5 to 1.17 pCi/g;
it is not unreasonable to assume, however, that a substantial, but unknown, volume of soil is
contaminated at these low levels. To estimate such volumes, it is necessary to extrapolate the soil
volume vs. contaminant concentration curve to lower concentrations.
A comparable situation prevails at sites contaminated with naturally-occurring isotopes of
uranium or thorium, which are found in the soil at background concentrations on the order of 1
pCi/g. Determining the volumes of soil contaminated at 0.1 to 1 pCi/g above background at such
sites is not technically feasible. In the case of some sites, however, it was necessary to
extrapolate the volume vs. concentration curves for the purpose of modeling the cleanup.
Because only one radionuclide is postulated for Reference Site I, the distribution could be
constructed from the tabulated data in a straightforward manner. If two or more nuclides are
present, but all originate from a common source and/or have similar chemical properties, the
situation is still relatively simple. For example, at sites contaminated with natural uranium, it is
assumed that the three principal uranium isotopes—U-234, U-235 and U-238—will always have
the same ratios of concentrations as are found in natural uranium ores.8 Thus, it is only necessary
to construct the distribution of one isotope, usually U-238: U-234 is then assumed to have the
identical distribution. The distribution of U-235 follows the same pattern, but its specific activity
is equal to 4.7% the activity of U-238 or U-234.
The presence of two or more nuclides at a given reference site which exhibit different patterns
of contamination results in a more complex situation. Such distributions are best represented by
plotting the concentration of each nuclide vs. the cumulative volume (i.e., the volume of soil
contaminated at or above a given concentration). An example of such a plot, showing the
distribution of radionuclides at Reference Site XII, is shown in Figure 4-3. (Except for the
presence of multiple nuclides, this plot resembles the one in Figure 4-2, but with the x- and y
8 As was observed in note 1, the term "radionuclide concentrations in the soil" is used to denote the specific
activity of a given nuclide. Thus, while the specific activities of U-238 and U-234 in natural uranium ores
are equal, because of the great disparity in their radioactive half-lives, the mass concentration of U-238, in
units of (ig/g of soil, is far greater than that of U-234.
Review Draft - 9/26/94 4-32 Do Not Cite Or Quote
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Figure 4-3
Reference Site XII
Distribution of Contaminated Soil
O
O
I
O
fit
O
^ 10,000
b
Q.
C
O
"CD
CD
o
c
o
O
"03
c/)
CD
X
03
1,000
100
10 =-
0.1 =-
0.01
5E+2
1E+3
2E+3 5E+3
Volume of Soil to be Removed (m**3)
Pu-239 Am-241
—• 4—
1E+4
2E+4
Total Contaminated Volume = 1.76E+4 m**3
-------
axes interchanged.) Implicit in the distributions shown in Figure 4-3 is the assumption that the
soil that contains the highest concentrations of one nuclide also contains the highest
concentrations of all the other nuclides, and so on down to the lowest extrapolated concentrations.
Once the soil cleanup level for a site is defined in terms of radionuclide concentrations, the
volume of soil that must be remediated at that site can be derived from such a volume distribution
curve. The cumulative volume then represents the amount of soil that must be remediated to
reduce the maximum residual concentration of each nuclide to the value depicted on the
corresponding curve.
If a basis site consists of sub-units, each of which is contaminated with a different mix of
radionuclides, the corresponding reference site is divided into sub-sites, each with its own
radionuclide distributions and, if indicated, different environmental parameters. This procedure
is discussed in the detailed description of Reference Site II in Section 4.4.3.
These curves play an integral role in the analyses of benefits and determinations of cleanup
volumes performed in support of the cleanup rule. For example, once a cleanup level is defined
for a site, the benefits of cleanup, expressed in terms of person-rem or adverse health effects
averted, can be derived (see discussion Section 5.2). Similarly, any adverse effects associated
with the cleanup operation itself can be estimated, including impacts on workers and the nearby
public, transportation impacts, and ecological impacts. The volume of soil that may need to be
remediated is a major factor in assessing the economic cost of cleanup.9
A detailed description of the methods used to construct the radionuclide distributions for each of
the 16 reference sites, along with figures illustrating these distributions, is found in the following
section.
9 Because of limitations in the data characterizing the sites that are the basis for the reference sites, thes e
curves are highly uncertain and as such are one of the largest sources of uncertainty in subsequent
assessments of risks and evaluations of benefits. As work proceeds in subsequent sections toward th e
development of estimates of soil cleanup volumes and the number of adverse effects averted and caused as
a result of site cleanup, there will be a tendency to read into these estimates a level of precision that does
not exist. All estimates of risks, cleanup volumes and benefits based on these volume distributions are at
best rough approximations of the actual conditions at the various sites.
Review Draft - 9/26/94 4-34 Do Not Cite Or Quote
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4.4.3 Description of Reference Sites
As previously indicated, the data on soil contamination at actual sites that are the basis for the
reference sites are often incomplete. Continuing efforts are being made to obtain improved site
characterization data.
The environmental parameters that form part of the description of each of the non-generic
reference sites are discussed under the corresponding subheading for each reference site.
Whenever possible, these parameter values, which were needed for the analyses of the reference
sites, were based on data collected at the basis sites. If actual values were not listed in the
references for a given site, representative values typical of the type of soil at that site or of other
known geologic or meteorological conditions were used.
REFERENCE SITE I
Reference Site I is based in part on radiological and environmental data for DOE's Hanford
Reservation. It is essential to bear in mind that the following analysis of this reference site,
although it makes use of some of the data that characterize Hanford, cannot be considered to be
an analysis of the actual site. In particular, the predicted impacts refer only to the reference site
and cannot be used to predict the future impacts of the vastly more complicated Hanford
Reservation.
Description of Basis Site
The Hanford Reservation encompasses about 360,000 acres (560 square miles) in southeastern
Washington State and borders the Tri-Cities area of Richland, Pasco and Kennewick (pop. about
140,000) to the south. Its primary mission since World War II has been the production of
plutonium for nuclear weapons.
Four aggregate areas at Hanford are on the CERCLA National Priorities List:
• The 100 Area, which includes nine plutonium production reactors;
The 200 Area, which includes the PUREX reprocessing plant, other plutonium
recovery facilities, a plutonium finishing plant, and about 170 large underground
tanks holding high-level waste;
Review Draft - 9/26/94 4-3 5 Do Not Cite Or Quote
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• The 300 Area, which includes fuel fabrication and research and development
facilities; and
• The 1100 Area, including vehicle maintenance facilities.
There are 78 operable units (OUs) at Hanford, including:
• 23 OUs in the 100 Area, including 9 reactors and supporting facilities.
• 43 OUs in the 200 Area, including most of the radioactive and mixed waste stored
or disposed of at the site and large volumes of contaminated soil.
6 OUs in the 300 Area, including burial grounds, cribs, ponds, ditches and
chemical spill sites.
• 3 OUs in the 1100 Area, including waste burial grounds.
Large quantities of liquid wastes have been discharged to the ground at various site locations
throughout Hanford's almost 50 years of operation. Soil contamination exists at approximately
87 cribs into which liquid wastes have been disposed, as well as 34 burial grounds, 57 trenches,
13 ditches, 27 French drains10, 10 ponds, and a large but undetermined number of "unplanned
release" sites. In a presentation to the Committee on Government Operations of the U.S. House
of Representatives (DOE 94c), DOE reported that the principal radionuclides at Hanford include
Am-241, Cs-137, Co-60, isotopes of plutonium and uranium, Tc-99, and Sr-90.
Environmental Parameters.
At all reference sites, external radiation is the principal human exposure pathway from Cs-137,
the only nuclide modeled at Reference Site I (see discussion below). The maximum risk and dose
occur at time zero; transport to the aquifer is therefore irrelevant to the assessment of risk and
dose to the RME individual. For the population impacts, which are integrated over long periods
of time (up to 10,000 years), the groundwater pathway also makes no significant contribution.
Even for a relatively shallow aquifer, radioactive decay will reduce the activity of Cs-137 (which
has a half-life of approximately 30 years) to an insignificantly low level during the time required
for the contamination to travel through the soil column to the aquifer. Nevertheless, for
consistency with the analyses of other reference sites, and for use in possible future analyses
10 A French drain is a nearly vertical perforated pipe of large diameter that extends 16 to 20 feet below th e
surface.
Review Draft - 9/26/94 4-36 Do Not Cite Or Quote
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which might include other, longer-lived nuclides, values of environmental parameters were
assigned to this reference site.
The vadose zone consists of alluvial and windblown deposits (Wo 93:169). In the absence of
site-specific data, representative values of hydraulic parameters of sandy soil, tabulated in the
RESRAD references (ANL 93b, DOE 93a), were assigned to the vadose zone of Reference Site
I (see Table 4-8). The annual precipitation at Hanford is 0.2 m/yr (Wo 93:81); however, no
infiltration rate data were available. An infiltration of 0.15 m/yr, representative of the arid
conditions at Hanford, was assigned to Reference Site I. The Kd for Cs-137 at Reference Site I
was given the representative value for sandy soil listed in the RESRAD tables.
An unconfined aquifer is found 1 to 348 feet (0.3 - 106 m) below the surface of the Hanford Site.
This aquifer consists of river and lake sediments which range from sandy gravel to compacted
silt and clay, plus glacial alluvial sediments (Wo 93, p. 169). Since most of the contamination
indicated in the aerial survey is found in the 200 Area, which is at elevations of 60 to 70 m above
the water table, a value of 50 m was selected as a conservative value for the depth to aquifer at
Reference Site I. Other hydrogeological properties were assigned the representative values for
sandy soil found in the RESRAD tables (ANL 93b). Groundwater gradients were not available
in the survey data; a conservative value of 10"4 was assigned to Reference Site I.
Soil Contamination
Data sources. As far as could be determined, there are no available reports of any systematic
sampling and analysis that would enable the radionuclide contamination of the Hanford soils to
be fully characterized. Small numbers of soil samples are collected and analyzed yearly for the
purpose of monitoring off-site fugitive dust emissions. The only site-wide radiological data
consist of aerial surveys performed for DOE by EG&G Energy Measurements.11 The surveys,
which were performed in May and June, 1978 consisted of overflights by an aircraft carrying
arrays of Nal crystals with an energy window centered on the 661 keV gamma radiation emitted
by Ba-137m, the short-lived daughter product of Cs-137. (This is commonly spoken of as the
Cs-137 gamma ray). The report (EGG-1183-1828) presents isopleths delineating regions of
different levels of Cs-137 contamination superimposed on aerial photos of the area. The data are
presented as calculated exposure rates at an elevation of 1 m that are due to Cs-137 gamma
11 A report on the 1988 aerial survey of this site was received too late to be used in the present analysis.
Review Draft - 9/26/94 4-37 Do Not Cite Or Quote
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radiation. Conversion factors in the report enable the calculation of areal concentrations, which
can in turn be converted to the specific activities that are listed in Table 4-9. The areas listed in
the table were determined by the methods described in Section 4.1.3, above.
Table 4-9. Areas of Cs-137 Contamination at the Hanford Site
Concentration
(pCi/g)
Area (m2)
1.17-
5.85
1.49E7
5.85-
18.7
4.59E6
18.7-
58.5
1.84E6
58.5-
102
3.81E5
102-
550
8.60E5
550-
948
6.10E4
948-
2930
4.63E4
Although an aerial survey cannot determine the depth profile of the contamination (separate
analyses of soil samples are needed for this) the attenuation of the Cs-137 gamma ray by soil
leads to a rapid fall-off of the count rate in the detector with increasing depth of burial. For
example, the exposure rate at an altitude of 30 m from a planar disk source of Cs-137 with a
radius of 140 m buried at a depth of one meter is four orders of magnitude less than from one that
is 2 cm deep, the source-to-detector distance remaining constant (based on calculations using the
Microshield computer code). If the depth is increased to two meters, the exposure rate is reduced
by nine orders of magnitude. Thus, deeply buried wastes make but a small contribution to the
apparent soil concentrations. A more serious shortcoming of these data is the poor spatial
resolution of the survey (see "Sources of error" in Section 4.1.3). If intense but localized sources,
such as highly radioactive materials stored in barrels or in lightly shielded structures are present,
the survey will report them as diffuse areas of contamination.
Modeling of contamination. Reference Site I was modeled on the assumption that the aerial
survey readings stem from Cs-137 that is uniformly distributed in the top 5 cm of the soil, that
no other sources of Cs-137 were present in the detectors' fields of view, and that there is no other
radioactive contamination of the soil attributable to the operation of the Hanford site.
The 5-cm depth of contamination was selected for several reasons. First, the Hanford
environmental sampling program collected samples to depths of 2.5 cm (Wo 93:149), suggesting
there was little reason to go deeper. Second, it is the least thickness of soil that can be reasonable
remediated during a cleanup operation. Thus, the cleanup volume would not be less even if the
depth were indeed smaller. Third, the aerial survey data was presented in terms of exposure rates
(|iR/hr) @ 1 m above the surface. Factors for converting exposure rates to surface concentrations
(|iCi/m2) were presented in the report. For a given exposure rate, assuming a greater depth would
decrease the specific activity.
Review Draft - 9/26/94
4-38
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To construct the radionuclide distribution shown in Figure 4-4, the areas listed in Table 4-9 were
converted to volumes of soil, again assuming a depth of 5 cm. The Cs-137 background
concentration (due to world-wide fallout), which is about 0.5 pCi/g at the Hanford Site (Wai 94),
was subtracted from each of the listed concentrations. A log-log extrapolation of the two lowest
data points was performed to enable the modeling of cleanup to low risk levels (see Chapter 5).
The total contaminated soil volume above 1 pCi/g (including background) ,1.53xl06 m3, is
considerably less than the 3.9xl06 m3 reported in the 1993 DOE Integrated Data Base (IDE). It
should be noted that the present analysis excludes waste disposal areas.
The assumption that Cs-137 is the only radioactive contaminant on Reference Site I stems from
the lack of information on the spatial distribution of other nuclides and on indications that Cs-137
is in fact the chief contaminant. The limited soil sample data reported in the Hanford
Environmental Report (Wo 93) lists analytical results for four radionuclides: Cs-137, Sr-90,
Pu-239,240 and U-238. In 1991, the last year in which as many as 15 on-site soil samples were
analyzed (there were only three in 1992), the average concentration of Sr-90 was about half of
that of Cs-137. Furthermore, in only two of the 14 samples for which both nuclides were
determined was the Sr-90 concentration higher than that of Cs-137. The concentrations of
plutonium are well below 1 pCi/g, and therefore make little contribution to the risk, while those
of U-238 are within the range of natural soil background. If, in fact, the cesium-contaminated
soils contain other radionuclides as well, it is assumed that these contaminants will be cleaned
up at the same time as the cesium. The present analysis does not take credit for the benefits
accruing from the remediation of contaminants other than Cs-137 at Reference Site I.
Analyses of the groundwater at Hanford have shown radioactive contamination, with
concentrations of H-3, Tc-99, Cs-137, Sr-90, Co-60 and uranium in excess of the proposed
Drinking Water Standard having been measured under several areas of the site (Wo 93, p. 180
etseq.). This contamination is the result of waste disposal practices that allowed liquid effluents
to be discharged to the soil column. There is no indication that the contaminated surface soils
make any significant contribution to these concentrations.
Recently released RI/FS documents for the Hanford Site are reported to contain new data on the
radioactive contamination of the soils. Future analyses will incorporate such data.
Review Draft - 9/26/94 4-39 Do Not Cite Or Quote
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O
o
O
fit
O
D)
> 1,000
CD
O
05
.0)
O 100
ro 10
CD
O
c
o
O
ro
^
p
(/)
CD
C£
E
^
E
'x
05
0.1
0.01
1E+3
Figure 4-4
Reference Site I
Distribution of Contaminated Soil
3E+3
1E+4 3E+4 1E+5 3E+5
Volume of Soil to be Removed (m**3)
Cs-137
1E+6
3E+6
Total Contaminated Volume = 1.53E+6 m'
-------
REFERENCE SITE II
Reference Site II is based in part on radiological and environmental data for the Fernald
Environmental Management Project (FEMP). It is essential to bear in mind that the following
analysis of this reference site, although it makes use of some of the data that characterize Fernald,
cannot be considered to be an analysis of the actual site. In particular, the predicted impacts refer
only to the reference site and cannot be used to predict the future impacts of the much more
complicated FEMP site.
Site Description
The Fernald Environmental Management Project, formerly known as the Feed Materials
Production Center (FMPC), is on the CERCLA NPL list. It covers 1050 acres and is located 17
miles northwest of Cincinnati, Ohio. Uranium metal products for the nation's defense programs
were produced at the facility between 1953 and 1989. During those years, the facility produced
slightly enriched or depleted uranium products for use in production reactors to make plutonium
and tritium at other DOE sites.
In addition to uranium, thorium has been stored at Fernald since the mid-1960s when the U.S.
was studying the use of the thorium/uranium fuel cycle for commercial production of electricity.
Approximately two-thirds of the thorium at Fernald was processed on site, with the remaining
portion originating from other DOE facilities.
Contaminated areas at the site include waste pits/settling ponds and waste silos containing
uranium and radium residues. The radionuclides present at the site include Pu-238, Pu-239, Ra-
226, Ra-228, Sr-90, Tc-99, Th-230, Th-232, Th-228, U-234, U-235/U-23612, and U-238.
In July 1989, uranium metal production was suspended. In December 1989, the site was added
to the EPA National Priorities List of federal facilities in need of remediation. DOE announced
its intention to formally end the production mission in February 1991, and closure became
effective in June 1991.
Environmental restoration efforts under the Fernald RI/FS address five operable units (OUs) at
the site:
12 U-235 and U-236 specific activities are lumped together in the FEMP data. In the present analysis, all these
activities are attributed to U-235.
Review Draft - 9/26/94 4-41 Do Not Cite Or Quote
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OU-1: Waste storage units
OU-2: Solid waste units
OU-3: Facilities and Suspect Areas
OU-4: Special facilities
OU-5: Environmental media
Environmental Parameters
The vadose zone at the FEMP consists of a silty clay glacial till (FEMP 93, p. 10). The
infiltration rate was calculated to be 0.30 m/yr (DOE 93b, p. 2-7). This value, along with
representative values of hydraulic parameters of silt/clay that are tabulated in the RESRAD
references (ANL 93b, DOE 93 a) were assigned to the vadose zone of Reference Site II.
The uppermost water-bearing unit consists of sand and gravel material (FEMP 93, p. 10). In the
absence of site-specific data, the exponential parameter (b) and total and effective porosities in
the saturated zone of Reference Site II were assigned representative values for sand and gravel
that are listed in the RESRAD tables. Groundwater gradients at Fernald are variable, with
average values of 7.5x10"4 to IxlO"3 being reported for the FEMP, and values as high as 2.7xlO"3
being reported within a 5 km radius of the site. The geometric mean of the on-site values, 8.7x10"
4, was assigned to Reference Site II.
The transmissivity in the aquifer is 40,000 to 67,000 ft2/day; the aquifer underneath the site is
approximately 70 ft thick (DOE 93b, p. 2-6). These data can be used to calculate the hydraulic
conductivity, using the relationship shown in the following equation13:
K = T/b
where
T = transmissivity
K = hydraulic conductivity, and
b = aquifer thickness
13 Freeze and Cherry (Fr 79) define transmissivity as
T = Kb
This equation can be manipulated to derive the value of K if T and b are given.
Review Draft - 9/26/94 4-42 Do Not Cite Or Quote
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The hydraulic conductivities at Fernald range from 64,000 to 106,000 m/yr. The geometric mean
of this range, approximately 82,000 m/yr, was assigned to Reference Site II.
The depth to the water table at Fernald generally ranges from 6-15 m (FEMP 93, p. 10), but may
be as shallow as 0.3 m or as deep as 25 m (FEMP 93, p. 12). The geometric mean of
approximately 10m was assigned to Reference Site II.
No Kd values were found in the survey data for Fernald. Kd values assigned to each radionuclide
at Reference Site II on the basis of representative values for clay soils in the RESRAD tables.
Soil Contamination
Data sources. The radionuclide contamination of on-site soils at the FEMP has been extensively
studied as part of the RI/FS process (DOE 93b); more limited studies of off-site soil
contamination have also been performed (DOE 93c).
The contaminated surface soils in OU 5 of the FEMP form the basis of the soil contamination at
Reference Site II. OU 5 includes all on-site and off-site soils outside of the waste storage units.
The Site-Wide Characterization Report presents the results of surface analyses for six of the sub-
units of OU 5 (DOE 93c: App. R). Included are the following data on the concentrations of 12
radionuclides: the total number of samples analyzed for each nuclide, the number of samples in
which the nuclide was detected, the upper 95th percentile limit on the background activities of
the nuclide, the range of activities detected, the mean and the upper 95th percentile confidence
limit on the mean. These data can be used to create the radionuclide distributions, as described
in the following section.
Off-site contamination data for the upper 5 cm of soil were presented as a map of the site vicinity
with isopleths corresponding to uranium concentrations of 5 to 35 |ig/g, in increments of 5 |ig/g
(DOE 93b). In the present analysis, the areas bounded by each isopleth were determined in much
the same way as was done for the aerial survey maps for other sites. The total (not incremental)
areas, excluding the area of the site itself, bounded by each isopleth, are listed in Table 4-10,
below.
Review Draft - 9/26/94 4-43 Do Not Cite Or Quote
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Table 4-10. Areas of Uranium Contamination Adjacent to FEMP
1 Concentration (ng/g)
Area (m2)
:>5
6.81E6
:>10
1.65E6
2:15
6.04E5
:>20
1.23E5
:>25
6.7E4
:>30
3.2E4
,35 I
6E3 I
Modeling of contamination. The layer comprising the upper 18 inches of soil of six of the sub-
units of OU 5 was the basis for sub-sites 1-6 of Reference Site II. Although data on subsoils
(soils deeper than 18") at the FEMP are also available, these deeper layers were not used to
construct the reference site for several reasons. First, the contaminated volumes are not
contiguous—lenses of contaminated soil are present at various depths. Such lenses are not
compatible with the simplified models of the reference sites used in the present analyses, since
these models assume that the radionuclide distributions are continuous. Second, the subsoil data
are less complete than the surface soil data and contain some ambiguities, e.g.., some nuclides are
listed as positively detected although their maximum concentrations are below background.
Of the 12 nuclides for which surface soil concentration data are listed, the following eight were
selected for analysis: Ra-226, Th-230, Ra-228, Th-228, Th-232, U-234, U-235 and U-238. The
others had ranges of concentration that were comparable to background or that were low enough
to have no effect on the present analyses.
Given the mean (|i), the upper 95th percentile confidence limit on the mean (|i95), and the number
of samples (n), it is possible to characterize the corresponding normal or log-normal distribution.
In the case of a normal distribution, |i95 is determined by the following expression (Gil 87:134
et seq.):
95
= H + Z950A/n
= standard deviation
= 95th percentile of the standard normal distribution
= 1.645
A normal distribution is completely determined by the mean and the standard deviation;
therefore, solving for a in the above expression yields the desired information.
Review Draft - 9/26/94
4-44
Do Not Cite Or Quote
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Normal or log-normal distributions were constructed for each of the eight nuclides at each of the
six sub-sites.14 The distributions were truncated at the upper end, with a value approximately one
order of magnitude above the highest measured concentration in a particular subunit forming the
upper limit. The potentially contaminated soil volume at each sub-site was assumed to equal the
area of the given subunit multiplied by 18 inches (46 cm), the depth of the contaminated layer.
For sub-sites at which analyses of one or more samples failed to detect one of the eight nuclides,
the volume used to construct the distribution of that nuclide at that sub-site was reduced by the
ratio n/N, n being the number of samples with positive detection and N being the total number
of samples analyzed for that nuclide. The 95% UL of the background was subtracted from the
concentrations of each nuclide and the volumes of soil contaminated at or below that
concentration were calculated to produce the distributions shown in Figures 4-5 to 4-10. To
preserve legibility, only the four most significant nuclides are illustrated. Since the curves are
calculated as continuous distributions, individual data points are not marked.
The off-site soil contamination in the vicinity of the FEMP served as the basis of sub-site II-7.
Stevenson and Hardy (St 93) reported that the three uranium isotopes (U-238, U-235 and U-234)
in the off-site soils were found in the same relative abundance as in natural uranium. They also
reported that the natural background of total uranium in the top 5 cm of soil beyond the influence
of the site to be 2.2 pCi/g.
To construct the distributions of the three uranium isotopes at sub-site II-7, volumes of soil
contaminated to the depth of 5 cm were calculated from the areas listed in Table 4-10. The
chemical concentrations were converted to specific activities by multiplying each value by the
specific activity of each isotope in pure, natural uranium (approximately 0.334 pCi/|ig for U-238
and U-234 and 0.016 for U-235). Finally, the background activity was apportioned among the
three isotopes according to their relative abundances (1:0.047:1) and subtracted from each
calculated activity to construct the distributions illustrated in Figure 4-11. Since the distribution
of U-234 is identical to that of U-238, and since the distribution of U-235 parallels that of the
other two, only the U-238 distribution is shown.
14 Because radionuclide data were presented separately for the six sub-units at the FEMP, six sub-sites were
created in the present analysis. The analysis assumes that the same cleanup goal will be selected for th e
entire site, but that each sub-site will be remediated separately.
Review Draft - 9/26/94 4-45 Do Not Cite Or Quote
-------
o
o
O)
X
CD
Figure 4-5
Reference Site 11-1
Distribution of Contaminated
CD
§ 1E+4
_Q I t+4
CO
D)
t ^ t+o
Q_
C1 P-i-9
O
'-4— '
CD
"c
CD
O
O
CO 1 C 1
3 1E~1
m ICO
y 1 t-^
Di
1 1C3
J I C-O
E (
= IT— — ^
-
- -
1 -.
= ""••-•.....
-
=
II
D
..
~ *= — ~
-
1 1 1 1
5 1
— ^^^^_^^^
" - - -
iii;.
0 1
"^^^^^— ___^
- -
i i i i
5 2
'---__
ii
0 2
~~" -\^^
-
ii
5 3
V
- --^
0
\
I
I
' I
I "
"
— T ^
"
v
I
3
Volume of Soil to be Removed (m**3)
Thousands
Ra-226 Th-230 Th-232 U-238
Total Contaminated Volume = 3.30E+4 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-235
-------
o
o
.a
CD
o H
& '
05
.0)
o 1
c 1
o
"05
S_ -|
"c
CD
O
o
o
IE+0
05 1E-1
1E-2
0
X
CD
10
Figure 4-6
Reference Site II-2
Distribution of Contaminated Soil
20 30 40 50 60
Volume of Soil to be Removed (m**3)
Thousands
Ra-226 Th-230 Th-232 U-238
Total Contaminated Volume = 5.76E+4 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-235
70
80
-------
9/26/94
oo
O
o
I
O
r?
O
/D
|
rt
D)
.a
0
o -i
CO
.O)
O
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-*—>
c
0
o
o
O
"co
0
X
(0
Figure 4-7
Reference Site 11-3
Distribution of Contaminated Soil
11
IE-3
5 6 7 8 9 10 11
Volume of Soil to be Removed (m**3)
Thousands
Ra-226 Th-230 Th-232 U-238
12
13
14
15
Total Contaminated Volume = 1 .07E+4 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-235
-------
VO
O)
.^
.Q
CD
>
O
-g 1,000
D)
CO
CD
Figure 4-8
Reference Site II-4
Distribution of Contaminated Soil
100
10
O
Q.
c
O
"CD
s_
"c
CD ,
O 1
C
O
O
— 0.1
03
0.01
=3 0.001
E 2
'x
03
5 10 20
Volume of Soil to be Removed (m**3)
Thousands
30
50
o
o
O
s
o
/D
Ra-226 Th-230 Th-232 U-238
Total Contaminated Volume = 4.27E+4 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-235
-------
J^.
I
o
o
o
O
fit
O
/D
O)
.Q
CD
O
.Q
03
.O)
O
Q.
C
O
C
CD
O
C
o
O
~03
X
03
Figure 4-9
Reference Site 11-5
Distribution of Contaminated Soil
1E+2
IE--
IE-^
1E-3
1E+1
2E+1
5E+1
1E+2 2E+2 5E+2
Volume of Soil to be Removed
(m**3)
Ra-226 Th-230 Th-232 U-238
1E+3
2E+3
5E+3
Total Contaminated Volume = 4.15E+3 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-235
-------
O
o
O
fit
O
D)
^
_Q
CD
O
-Q 1E+4
cc
Figure 4-10
Reference Site 11-6
Distribution of Contaminated Soil
6 1E+3
^.
.1 1E+2
"OB
~ 1E+1
CD
O
O 1E+0
O
"§ 1E-1
0) 1E-2 L
3 1E-3
E 1E+3 3E+3 1E+4 3E+4 1E+5 3E+5 1E+6 3E+6
£ Volume of Soil to be Removed (m**3)
Ra-226 Th-230 Th-232 U-238
Total Contaminated Volume = 5.76E+4 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-235
-------
J^.
I
to
O
o
Figure 4-11
Reference Site 11-7
Distribution of Contaminated Soil
3E+3 1E+4 3E+4 1E+5
Volume of Soil to be Removed (m**3)
U-238
3E+5
1E+6
Total Contaminated Volume = 2.36E+5 m**3
Additional Nuclides: U-234 and U-235
-------
Quality of data. The characterization of the on-site soils appears to be comprehensive, including
over 400 separate determinations for each nuclide studied. The individual values were not
presented in the report, however, requiring the present analysis to estimate the distribution of
concentrations, as discussed above.
The distribution of the off-site soil concentrations was directly determined from the isopleths.
The accuracy and completeness of those data has been critiqued in the course of the
requalification of the data. Stevenson and Hardy (St 93) concluded that the data were reliable,
except for a low bias for concentrations less than about 1.3 pCi/g of U-238. Since the lowest
isopleth corresponds to 1.7 pCi/g of U-238, the data used in the present analysis were not
affected.
REFERENCE SITE III
Reference Site III is based in part on the Idaho National Engineering Laboratory (INEL). It is
essential to bear in mind that the following analysis of this reference site, although it makes use
of some of the data that characterizes INEL, cannot be considered to be an analysis of the actual
site. In particular, the predicted impacts refer only to the reference site and cannot be used to
predict the future impacts of the vastly more complicated INEL site.
Basis Site Description
The Idaho National Engineering Laboratory (INEL) is on the CERCLA NPL list. It encompasses
an area of approximately 890 square miles of desert in southeastern Idaho on the northwestern
edge of the Eastern Snake River Plain. The INEL boundary is about 22 miles west of Idaho Falls
and 44 miles northwest of Pocatello.
In spite of INEL's large size, most operations are located at nine relatively small (generally less
than 200 acres), discrete areas including:
Test Area North (TAN);
Test Reactor Area (TRA);
Central Facility Area (CFA);
• Radioactive Waste Management Complex (RWMC);
Auxiliary Reactor Area (ARA);
• Power Burst Facility (PBF)/Special Power Excursion Reactor Test (SPERT) area;
Naval Reactor Facility (NRF);
• Idaho Chemical Processing Plant (ICPP); and
• Argonne National Laboratory - West (ANL-W).
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INEL's functions include separating enriched uranium from spent fuel at the ICPP, operation of
a large number of research reactors, and storage of transuranic wastes. Radionuclides present at
INEL include Am-241, Cf-252, Cm-244, Cs-137, Cs-134, Co-60, Eu-152, Eu-154, H-3,1-129,
Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Ru-106, Sb-125, Sr-90, U-234, U-235, U-238, U-233,
andU-236(DOE94c).
INEL's remedial action plan divides the site into ten Waste Area Groups (WAGs). WAGs 1-9
generally correspond to the DOE-INEL Operational Facilities listed above, while WAG 10
corresponds to overall concerns associated with the Snake River Plain Aquifer (SRPA) and those
surface and subsurface areas not included in the bounds of the facility-specific WAGs.
Environmental Parameters
The soil type for the contaminated and unsaturated zones was identified as silty clay loam
underlain with sand and gravel beds (EGG 92a, pp. 40-42). In the absence of site-specific data,
values for silty clay loam were selected from tables of representative values in the RESRAD
references (ANL 93b, DOE 93 a) to characterize the hydraulic properties of the vadose zone of
Reference Site III. The annual precipitation rate at INEL is 0.22 m/yr, with an evaporation rate
of 0.91 m/yr; the irrigation rate in the area is high (INEL 77, pp. 11-213 to 11-223). Based on these
data, an infiltration of 0.15 m/yr, representative of the arid conditions at INEL, was assigned to
Reference Site III.
The uppermost water-bearing unit consists of sands and silts over fractured basalt (EGG 92a, p.
45 and INEL77, p. 11-227). The saturated zone of Reference Site III was assigned a hydraulic
conductivity corresponding to the upper end of the range for fractured igneous rocks, listed in the
RESRAD tables, along with representative values of the exponential parameter (b) for sandy
loam, and the total and effective porosities of fractured basalt. The groundwater gradient was
assigned the value of 0.002, the average gradient measured at INEL (INEL 77, p. 11-227).
The sandy loam layer at INEL, which is 11 to 40 ft thick, overlies a 1 to 10 ft layer of clayey
sands (EGG 92a, p. 40). These layers are underlain by sand and gravel beds above a layer of
fractured basalt that makes up the Snake River Aquifer. The estimated depth to the aquifer, 100
m, was assigned to Reference Site III.
No Kd values were found in the survey data for INEL. A representative Kd value for Cs-137 in
clay or silty soils listed in the RESRAD tables was assigned to Reference Site III.
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Soil Contamination
Data sources. A preliminary assessment of soil contamination has been performed by EG&G
Idaho (Ma 92). Systematic soil samples, collected over an area of about 60,000 m2, indicated that
the main nuclide of concern was Cs-137. The only other artificially produced radionuclide was
Co-60; the median concentration was less than 0.1 pCi/g, which poses an insignificant risk
compared to the much higher levels of Cs-137. Other nuclides were within the range of natural
soil background concentrations for the local soil type. The sampling results indicate that the
depth of contamination is approximately 15 cm; the contaminated volume at this sub-site is
therefore estimated to be 9,000 m3. Systematic samples at a second INEL sub-site indicated a
slight Cs-137 contamination—maximum concentration of 1 pCi/g—in a volume of 5,000 m3.
The remainder of the soil assessment was based on biased samples (samples collected in known
"hot" spots) and therefore cannot be used to characterize the INEL site.
A more comprehensive site-wide data source was an aerial survey performed by EG&G Energy
Measurements (Report EGG-10282-1002). The report includes aerial photos of the area with
isopleths showing regions with different count rates in the energy range of the gamma-ray of
Ba-137m, the short-lived daughter of Cs-137. A conversion factor in the report, based on a
uniform volume distribution, enables the calculation of specific activities of Cs-137 in the soil.
The areas of soil at different concentrations are listed in Table 4-11.
Table 4-11. Areas of Cs-137 Contamination at INEL
1 Concentration (pCi/g)
Area (m2)
1-10
1.20E7
10-100
3.51E6
100-300 1
1.44E6 1
The total area contaminated by Cs-137 at soil concentrations in excess of 1 pCi/g is
approximately 16 km2. The volume of contaminated soil reported in the 1993 IDE is 660,000 m3.
Modeling of contamination. Dividing the IDE volume by the contaminated area yields an
average depth of contamination of 4 cm. As a practical matter, the shallowest soil layer that can
be remediated is approximately 5 cm. This is also the depth of the soil samples collected by
EG&G Idaho, indicating that deeper soils were not a cause for concern. This was therefore
assumed to be the thickness of the contaminated layer at the reference site, yielding a volume of
soil with Cs-137 concentrations at or above 1 pCi/g of about 8xl05 m3, somewhat more than
Review Draft - 9/26/94 4-55 Do Not Cite Or Quote
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the IDE value. This assumption was discussed in greater detail in the section on soil
contamination at Reference Site I, which appears above. A discussion of the limitations of the
aerial survey data is found in the same section, as well as in Section 4.1.2 of this report.
To construct the distribution of Cs-137 in the soil of Reference Site III, it is necessary to subtract
the Cs-137 background from world-wide fallout from the values in Table 4-11. There is no
available data on the Cs-137 background at INEL; the nearest location for which this data are
available is Hanford. Since both sites are in the same geographical region and at approximately
the latitude, the average Cs-137 background at Hanford, 0.5 pCi/g, was assigned to Reference
Site III. The distribution of Cs-137 in the soil of Reference Site III, illustrated in Figure 4-12,
was constructed by calculating the volumes in the upper 5 cm of soil, given the areas listed in
Table 4-11.
REFERENCE SITE IV
Reference Site IV is based in part on the soil in the chemical plant area of the Weldon Spring
site. It is essential to bear in mind that the following analysis of this reference site, although it
makes use of some of the data that characterize Weldon Spring, cannot be considered to be an
analysis of the actual site. In particular, the predicted impacts refer only to the reference site and
cannot be used to predict the future impacts of the much more complicated Weldon Spring site.
Basis Site Description
Weldon Spring is a 229-acre site located about 30 miles west of St. Louis Missouri. The site was
used by the Army in the 1940's as an ordnance supply area and then by the Atomic Energy
Commission for the processing of uranium and thorium until they closed it in 1966. Both the
DOE and the Army are responsible for portions of the site, which has been listed on the CERCLA
National Priorities List. Areas to be remediated include a 9-acre quarry containing radioactively-
contaminated rubble and radioactively- and chemically-contaminated water, four waste lagoons
containing raffmate sludges and contaminated water, a chemical plant comprising 44 structures
and containing contaminated soil and building material, and vicinity properties having
contaminated soil.
Environmental Parameters
The soil in the contaminated and unsaturated zones consists of silty loam, silt and clayey silt
(DOE 92a, p. 3-2). The total porosity of the vadose zone of Reference Site IV is 36%, which
Review Draft - 9/26/94 4-56 Do Not Cite Or Quote
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Figure 4-12
Reference Site
Distribution of Contaminated Soil
D)
CD
> 100
03
,D)
O 80
c
o
"03 60
40
20
CD
C£
I °
X
03
10
20 50 100 200
Volume of Soil to be Removed (m**3)
Thousands
Cs-137
500
1,000
Total Contaminated Volume = 7.84E+5 m**3
-------
is the average of the porosities of three of the formations that comprise the vadose zone at
Weldon Spring (DOE 92b, Table 4.3-4). In the absence of site-specific data, the exponential
parameter (b) and effective porosities in the vadose zone of Reference Site IV were given
representative values for silty clay found in the RESRAD tables (DOE 93a, p. 230). Hydraulic
conductivities on the site ranged from 1.6xlO~n to 2.0xlO"7, with an average value of 1.2xlO"10
m/sec (DOE 92b, pp. 4-29 and 4-30). A more conservative value of IxlO"8 m/sec (0.315 m/yr)
was assigned to Reference Site IV.
The infiltration rate at Weldon Spring is not found in the references. However, the RESRAD
manual (DOE 93a, p. 198) presents a formula for calculating this rate on the basis of other
parameters. (This formula is reproduced on p 3-52 of the present report). The precipitation rate
at the site is 0.94 m/yr (DOE 92b, p. 4-3). No information was available for irrigation at the site,
so a default value of 0.2 m/yr representative of humid conditions was assigned. Similarly a
default evapotranspiration coefficient representative of humid areas of 0.5 was assigned. A
runoff coefficient of 0.34 was chosen as representative of the open land on the site and the silty
loam soil. These data and assumptions were used to derive an infiltration rate of 0.41 m/yr,
which was assigned to Reference Site IV.
The uppermost water-bearing unit consists of 3-15 m of weathered limestone (DOE 92a, pp. 3-2
to 3-3). In the absence of site-specific data, the exponential parameter (b) and total porosities in
the aquifer of Reference Site IV were given representative values for limestone (DOE 93a, p.
230). Table 4.6-10 (DOE 92b) lists the values of hydraulic gradients and hydraulic conductivities
between six different pairs of monitoring wells at the chemical plant site. By drawing lines
between these pairs on a map showing the contaminated areas of the site, it was possible to select
the flow path that traversed the largest zones of radioactive contamination. The gradient along
this path is 0.019. Two values of conductivity were determined for this path: the smaller of the
two, 0.024 m/day, (8.8 m/yr) was selected as the conservative value for Reference Site IV.
Calculated effective porosities at Weldon Spring range from 0.008 to 0.1453, with an average
value of 0.067. The average value was assigned to Reference Site IV.
The vadose zone thickness varies from less than 10.6 m to more than 19.7 m (DOE 92b, p. 4-28).
The unsaturated zone, as defined in RESRAD, is the difference between the vadose zone and the
thickness of the contaminated layer. Since a thickness of 11 cm is assumed for the contaminated
layer, as discussed in the section on modeling the contamination, below, 11.5m was selected as
a conservative value for the unsaturated zone thickness for Reference Site IV.
Review Draft - 9/26/94 4-58 Do Not Cite Or Quote
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The baseline risk assessment lists Kd values that are representative of the type of soil found at the
site (DOE 92a, pp. E-20 to E-21). These values were used in the analyses of Reference Site IV.
Soil Contamination
Data sources. A baseline assessment (DOE 92a) as well as a remedial investigation and
feasibility study (RI/FS) for this site have been completed (DOE 92b,c), and a record of decision
(ROD) has been issued (DOE 92d). As part of this process, the soil contamination has been
extensively characterized. A total of 387 boreholes were drilled in this area. Soil samples were
taken from these holes and analyzed for U-238, Th-230, Ra-226 and Ra-228. The studies
conclude that uranium is the main radioactive contaminant of concern, and that it is assumed to
consist of U-234, U-235 and U-238 in naturally occurring isotopic ratios. The analytical results
for each of the approximately 1,500 samples are presented in Appendix F to the RI report (DOE
92b). The specific activities of U-238 range from a maximum of 2,105 pCi/g to background
levels.
Modeling of contamination. The volumes of soil that contain total specific activities of U-238
in excess of 15 pCi/g and 60 pCi/g, respectively, were used to characterize the volume
distribution of uranium in the soil (DOE 92b:5-32, DOE 92c). A distribution of uranium at
Reference Site IV was constructed, based on the assumption that the logarithm of the
contaminated volume has a linear relationship to the log of the minimum level of U-238
contamination (specific activity minus background) in that volume.15 The Baseline Assessment
lists 1.2 pCi/g as the average local U-238 background, with an upper bound of 1.7 pCi/g (DOE
92a:2-40). Although cleanup to less than perhaps 2 pCi/g is not technically feasible, to enable
the modeling of cleanup to very low risk levels, the extrapolated volume with a specific activity
> 1.7 pCi/g U-238 was calculated as part of the present analysis. These volumes are listed in
Table 4-12. The distribution, constructed by subtracting the background from the listed activities,
is illustrated in Figure 4-13. As was the case for Site II-7, only the U-238 distribution is shown.
U-234 has an identical distribution, while that of U-235 has the same shape but the activities are
equal to 4.7% of the activities of each of the other two isotopes.
15 Linear regression analyses of the soil contamination data at other reference sites indicates that this is a
common relationship.
Review Draft - 9/26/94 4-59 Do Not Cite Or Quote
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J^.
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03
Figure 4-13
Reference Site IV
Distribution of Contaminated Soil
O)
.^
.a
CD
>
E 100
03
D)
8 50
Q.
20
c
o
"CD
^ 10
CD
O
c 5
O
O
2 -
0.5
30
50 100
Volume of Soil to be Removed (m**3)
Thousands
U-238
200
300
Total Contaminated Volume = 2.56E+5 m**3
Additional Nuclides: U-234 and U-235
-------
Table 4-12. Volumes of Soil Contaminated by U-238 at Reference Site IV
1 Concentration (pCi/g)
Volume (m3)
:> 60
34723
:> 15
63711
:> 1.7 1
2.6E5 1
The total area of the soil at the chemical plant site is 67 ha (6.7xl05 m2); however, above-
background uranium concentrations were detected in only 340 out of 387 boreholes. Assuming
that the boreholes were randomly distributed, it is estimated that 88% of this area, or 5.9xl05 m2,
is contaminated. To calculate the average thickness of the contaminated zone, the volume of soil
above 15 pCi/g, 63,711 m3, was used, resulting in a thickness of 11 cm at Reference Site IV..
Other nuclides measured in the soil are Th-230, Ra-228 and Ra-226. Both the concentrations of
these nuclides and the contaminated volumes are small compared to the uranium contamination.
Because the impact of these additional nuclides was expected to be small and because no
summary data for these nuclides was presented in the report, they were not included in the
analysis of the reference site.
Several vicinity properties were characterized as part of the Weldon Spring RI/FS. The levels
of radioactive contamination at these sites are low—their inclusion would have little impact on
the outcome of the present analysis. The quarry at Weldon Spring was used as a waste disposal
area—little if any of that site falls within the scope of the present report.
REFERENCE SITE V
Reference Site V is based in part on the soil contamination at the Savannah River Site (SRS).
It is essential to bear in mind that the following analysis of this reference site, although it makes
use of some of the data that characterize SRS, cannot be considered to be an analysis of the actual
site. In particular, the predicted impacts refer only to the reference site and cannot be used to
predict the future impacts of the vastly more complicated SRS.
Basis Site Description
The Savannah River Site is located on 325 square miles along the Savannah River near Aiken,
SC, about 22 miles southeast of Augusta, Georgia. Its primary mission has been the production
of plutonium and tritium for nuclear weapons. DOE has identified a total of 657 contaminated
buildings for possible decontamination and decommissioning (DOE/EM-0119). The SRS
Review Draft - 9/26/94 4-61 Do Not Cite Or Quote
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contains 15 major production, service, and research and development areas. The P, K, L, C, and
R areas house five production reactors near the center of the site in the 100 series buildings.
Chemical separations facilities are located in the 200 series buildings in the F and H Areas. The
F and H Areas also contain the main analytical laboratory, the plutonium metallurgical facility
and tritium processing buildings. The 300 series buildings of the M Area contain test reactors,
uranium metal fabrication facilities, target and alloy extrusion facilities, and a metallurgical lab.
The 400 buildings in the D Area purified heavy water for the production reactors. Waste
management facilities are located adjacent to the F and H areas. The principal radionuclides
present at the site include Am-241, Cm-243, Cm-244, Cs-137, Co-60, Eu-152, Eu-154, Eu-155,
H-3, 1-129, Na-22, Pu-238, Pu-239, Pu-240, Pu-242, Ra-226, Ra-228, Ru-106, Sb-125, Sr-90,
Tc-99, Th-232, U-234, U-235, and U-238 (DOE 94c).
Environmental Parameters
The contaminated and unsaturated zones consist of coarse to fine sand and silty clay with
localized gravel lenses, with a clay content of 20-40% (RAE 91, pp. 3-7/8). The hydraulic
conductivity at SRS ranges from 11 to 4,400 m/yr. The geometric mean value of 220 m/yr was
assigned to Reference Site V. In the absence of site-specific data, the values for the exponential
parameter (b) and total and effective porosities in the vadose zone of Reference Site V were
derived from tables of representative values for different type soils in the RESRAD manual.
Because there are no specific values for sandy, silty clay, the arithmetic means of the listed values
for sandy clay and silty clay were used.
The infiltration rate at Savannah River was not found in the references. The precipitation rate at
the site is 1.22 m/yr (RAE 91, p. 3-5). No information was available on irrigation at the site, so
a default value of 0.2 m/yr representative of humid conditions was assigned. Similarly, a default
evapotranspiration coefficient of 0.5, representative of humid areas, was assigned. A runoff
coefficient of 0.67 was chosen as representative of the open areas at the site and the sandy, silty
clay soil. As explained in the section describing Reference Site IV, above, these data and
assumptions were used to derive infiltration an rate of 0.41 m/yr, which was assigned to
Reference Site V.
The uppermost water-bearing unit consists of fine silty sand containing varying amounts of clay
(RAE 91, p. 3-9). The exponential parameter (b) and total and effective porosities in the
saturated zone of Reference Site V were assigned representative values for silty clay that are
tabulated in the RESRAD manual. Since the hydraulic conductivity in the aquifer was not
Review Draft - 9/26/94 4-62 Do Not Cite Or Quote
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available in the literature, the conductivity for Reference Site V was set equal to the conductivity
in the vadose zone, based on the similarity of the soil types in the two zones. No groundwater
gradient data was available from the survey data, so a conservative value of 0.0001 was assigned
to Reference Site V.
The depth to the aquifer at Savannah River ranges from near zero at the seepline to 5-12 m in the
F- and H-Area seepage basins being used to represent the site (RAE 91, p. 3-7). A value of 30
ft (9.14 m) was selected for Reference Site V.
A table of Kd values were provided for Savannah River (RAE 91, p. 2-15) based on the work of
Looney, et. al. (Lo 87). These values were used for the analysis of Reference Site V.
Soil Contamination
Data sources. Radioactive contamination of the soil has been investigated in only a few areas,
primarily the waste management facilities which do not fall into the scope of the present report.
A number of aerial surveys have been performed for this site; however, the survey reports and
the necessary conversion factors were not available in time for the survey data to be analyzed for
this report. The 1993 IDE reports a contaminated soil volume of 3.6xl06 m3 for this site.
Modeling of contamination. The limited soil analyses that had been performed as part of the
baseline risk assessment for the F- and H-area seepage basins and other environmental studies
indicate that Cs-137 is the main radioactive contaminant of concern. Analyses had been
performed of the aerial surveys of five other DOE sites at which Cs-137 was the primary
radioactive contaminant. (In addition to Hanford, INEL and Oak Ridge, which are discussed in
the present report, the surveys covered Los Alamos and West Valley.) The fractional area of
each site that falls within a given range of concentration is shown in Table 4-13.
The Cs-137 distribution at Reference Site V was assumed to have the same fractional distribution
as the arithmetic means listed above. Before calculating the soil volumes, it was necessary to
determine the threshold concentration of the soil volume reported in the IDE. This information
was not readily available through DOE channels—each site apparently uses its own methods of
estimating the volumes which are listed in the IDE. The only information that was obtainable
regarding threshold levels for Cs-137 in soils was from the NRC. The NRC currently requires
that soils at licensed facilities that are contaminated above 15 pCi/g of Cs-137 must be remediated
before the site can be released for unrestricted use (John 94). A log-linear
Review Draft - 9/26/94 4-63 Do Not Cite Or Quote
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interpolation of the arithmetic means listed in Table 4-13 predicts that 36% of the soil volume
will have Cs-137 concentrations above 15 pCi/g. Assuming that the volume reported in the
IDE represents this fraction of a larger volume, the total volume with Cs-137 concentrations
above 1 pCi/g is calculated to be approximately l.OxlO7 m3. Cs-137 background
concentrations in the soil at SRS range from 0.3 to 3.5 pCi/g. A value of 0.5 pCi/g was
selected for the Cs-137 background at Reference Site V. This background value was
subtracted from the concentrations listed above in constructing the distribution of Cs-137
contamination for Reference Site V, which is illustrated in Figure 4-14.
Table 4-13. DISTRIBUTION OF Cs-137 IN CONTAMINATED SOIL
Site
Name
Hanford
INEL
LANL
ORR
W.Val
A. Mean
G.Mean
S. D.
G.S.D.
Min.
Max.
Fraction of Soil Volume (%) vs. Specific Activity (pCi/g)
1 - 10
68.6425
71 . 9424
49.2866
34.0426
65.8307
57.9490
55.8923
14 .2748
1.3243
34.0426
71.9424
10 - 100
27 .4570
20 .4759
49.2866
42.5532
26.3323
33.2210
31.5072
10 .8472
1.3837
20.4759
49.2866
100 - 1000
3.7148
6.0874
1.4267
23.4043
7.8370
8 .4940
5.6811
7.7631
2.5012
1.4267
23.4043
<1000
.1857
1.4942
.0000
.0000
.0000
.3360
.5268
.5836
2.8363
.0000
1.4942
The vertical concentration profile was assumed to be equivalent to a uniform depth of
contamination of 5 cm, as was done for Reference Sites I and III. The rationale for this
assumption was presented in the discussion of Reference Site I, which appears earlier in this
section. Dividing this depth into the calculated volume of contaminated soil results in a
contaminated area of about 200 km2 or 77 sq. mi., which is 24% of the area of SRS. The
distribution of Cs-137 at Reference Site V is illustrated in Figure 4-14. The data discussed
-------
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Figure 4-14
Reference Site V
Distribution of Contaminated Soil
1,000
100
D)
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CD
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03
.O)
O
Q.
C
O
"ro
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10 ^
0.1
0
4 5 6 7 8 9 10 11
Volume of Soil to be Removed (m**3)
Millions
Cs-137
12
13
14
15
Total Contaminated Volume = 9.98E+6 m**3
-------
above is extrapolated to lower specific activities to enable the modeling of cleanup to low risk
levels.16
REFERENCE SITE VI
Reference Site VI is based in part on the soil contamination at the Oak Ridge Reservation
(ORR). It is essential to bear in mind that the following analysis of this reference site, although
it makes use of some of the data that characterize Oak Ridge, cannot be considered to be an
analysis of the actual site. In particular, the predicted impacts refer only to the reference site and
cannot be used to predict the future impacts of the vastly more complicated ORR.
Basis Site Description
The Oak Ridge Reservation has played a major role in both nuclear weapons production and
commercial nuclear energy research. The ORR, which encompasses an area of 37,000 acres,
consists of three principal facilities: Oak Ridge National Laboratory (ORNL), the Oak Ridge
Gaseous Diffusion Plant (ORGDP) and the Y-12 Plant. These three facilities and their
contaminated areas are described as follows:
ORNL
Past R&D and waste management activities at ORNL have produced numerous waste
disposal units contaminated with low-level radioactive and/or hazardous chemical wastes.
ORNL contains six burial grounds covering more than 200 acres, as well as contaminated
impoundments, ponds and liquid waste disposal areas. ORNL occupies approximately
2900 acres in the Melton and Bethel Valleys, 10 miles southwest of the City of Oak
Ridge, Tennessee.
K-25 Site
The K-25 site formerly produced enriched uranium hexafluoride for both defense and
commercial purposes. The plant was shut down in 1987. Radioactive wastes are
contained at the site in holding ponds, a burial ground and other facilities. K-25 occupies
1500 acres adjacent to the Clinch River, approximately 13 miles west of the city of Oak
Ridge.
16 According to a recently-published article, effluent releases totaling approximately 600 Ci of Cs-137 have
been reported at SRS--most of the activity remained on site. [Ref: Carlton, W. H., et al, 1994.
"Radiocesium in the Savannah River Site Environment." Health Phys. 67(3):233.] The parameters selected
for Reference Site V indicate an inventory of approximately 970 Ci of Cs-137 (see Table K-195 in the
present report). This is a very close correspondence, given the generic nature of the data used to construct
this reference site.
Review Draft - 9/26/94 4-66 Do Not Cite Or Quote
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Y-12 Plant
Y-12 has produced machined components for nuclear weapons internals, as well as
highly-enriched uranium metal to fuel tritium and plutonium production reactors at
Savannah River. The Y-12 Plant includes several facilities that have been used to treat,
store or dispose of solid and liquid chemical and radioactive wastes. The East Fork
Poplar Creek, which receives Y-12 effluent discharges, contains elevated levels of
radioactivity. Y-12 occupies 811 acres in the Bear Creek Valley about two miles from
downtown Oak Ridge.
The principal radionuclides at ORR include Am-241, Cm-244, Cs-134, Cs-137, Co-60, Eu-152,
Eu-154, Eu-155, H-3, Ni-63, Np-237, 1-129, Pu-238, Pu-239, Pu-240, Ra-226, Ru-106, Sr-90,
Tc-99, Th-230, Th-228, Th-232, U-233, U-234, U-235, and U-238 (DOE 94c).
Environmental Parameters
The soil in the vadose zone consists of clayey silt (ORNL 88, p. 14). In the absence of site-
specific data, values which correspond to silt/clay were selected from tables of representative
values in the RESRAD references (ANL 93b, DOE 93a) to characterize the hydraulic properties
of the vadose zone of Reference Site VI.
The precipitation rate at Oak Ridge is 1.33 m/yr, with an evapotranspiration rate of 0.79 m/yr and
a runoff rate of 0.43 m/yr (ORNL 88, pp. 16 and 17). Using the method described in the
RESRAD handbook (ANL 93b, p. 9-4), the infiltration rate for Reference Site VI was calculated
to be 0.76 m/yr.
The aquifer consists of weathered limestone with a gradient of 0.005, a hydraulic conductivity
of 11 m/yr and an effective porosity of 0.0023 (ORNL 88, p. 21)—these values were assigned
to Reference Site VI. In the absence of site-specific data, the total porosity in the saturated zone
of Reference Site VI was assigned the representative values for limestone that is listed in the
RESRAD tables. Since no exponential parameter (b) values for limestone are listed, that
parameter was assigned the same value it has in the vadose zone.
The depth to the water table at Oak Ridge varies greatly depending on the location. Portions of
the site are located near surface water bodies while other areas are located at higher elevations.
The Environmental Research Areas (WAG 13) used to determine "average" site conditions at Oak
Ridge have depths to the aquifer ranging from 2-10 m (ORNL 88, p. 20). The geometric mean
of «4 meters was assigned to Reference Site VI.
Kd values for the principal contaminants at the ORR—isotopes of uranium and cesium—were
Review Draft - 9/26/94 4-67 Do Not Cite Or Quote
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identified for four different areas at Oak Ridge in the survey data. Since the groundwater
pathway makes a negligible contribution to human exposure for Cs-137 (radioactive decay
reduces the activity to negligible levels during the travel to the aquifer), a higher cesium Kd leads
to a longer residence time of Cs-137 in the soil, resulting in higher population exposures to
external radiation. There would be no effect on the risk to the RME individual, since that risk
is based on Cs-137 concentrations in the soil at time zero, which are not affected by the Kd.
Therefore, the highest Kd reported at ORR for cesium (10,000) was assigned to Reference Site
VI. The Kd values reported for uranium at ORR exceeded the range reported in the general
literature. Since the groundwater pathway for uranium is potentially significant, the
representative Kd for uranium in clay soils that is listed in the RESRAD tables was assigned to
Reference Site VI.
Soil Contamination
Data sources. RI/FS studies have been performed on various sub-units of the ORR, notably the
K-1407-B/C ponds at the ORGDP and the East Fork Poplar Creek, which receives liquid
effluents from the Y-12 nuclear weapons plant. As with other sites, the emphasis of the RI/FS
efforts has been on low-level waste burial grounds, ground and surface water contamination, and
sediments, none of which are within the scope of this report. Although soil contamination is
addressed in some of the studies, a limited assemblage of sub-sites cannot adequately characterize
the size, complexity and variability of the ORR. Consequently, aerial survey data, despite their
limitations, provide the best overview of soil contamination on the entire reservation and were
used to characterize the soil contamination at the reference site.
The aerial survey, performed by EG&G in September, 1989, detected gamma radiation from
Cs-137 and from Pa-234m, the short-lived daughter product of Th-234 (EGG 92b). Th-234,
which has a radioactive half-life of 24 days, is in turn the daughter of U-238. U-238 that has
been in place for more than a few months can be assumed to be in secular equilibrium with its
short-lived daughters. Pa-234m can thus serve as a marker for U-238.
The aerial survey report includes maps of the area with isopleths delineating regions with
different count rates in the energy range of the gamma ray of Ba-13 7m, the short-lived daughter
of Cs-137, as well as isopleths showing count rates from the 1.0 MeV gamma ray of Pa-234m.
Conversion factors in the report, based on uniform volume distributions of each nuclide, enable
the calculation of specific activities of Cs-137 and Pa-234m in the soil. The lowest isopleth for
Cs-137 delineated areas with soil concentrations above 1.5 pCi/g. Pa-234m is much more
difficult to detect: less than 1% of its disintegrations produce gamma rays. Thus, only areas with
Pa-234m (and hence U-238) concentrations in excess of 175 pCi/g were mapped. The areas of
soil at different concentrations of each nuclides are listed in Table 4-14.
Review Draft - 9/26/94 4-68 Do Not Cite Or Quote
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Table 4-14. Contamination of Surface Soils at Oak Ridge
Nuclide
Concentration (pCi/g)
Area (m2)
Cs-137
1.5-12.5
3.6E6
12.5-105
2E6
105-1250
1.1E6
Pa-234m
175-1130
1.1E6
1130-5.75E4
5.5E5
Modeling of contamination. The 1993 IDE lists contaminated soil volumes for four areas at
Oak Ridge: the K-25 Site, ORNL, ORR (off-site) and the Y-12 plant. The total volume for all
soil categories for the four areas is 4.3xl05 m3. This volume may be compared to the area
contaminated by U-238 if it is assumed that the IDE volume consists of soil with total uranium
activities above the NRC free release limit of 30 pCi/g. (DOE has not established generic cleanup
levels for uranium.) For uranium with relative isotopic abundances equal to natural uranium, this
corresponds to approximately 15 pCi/g U-238. Log-linear extrapolation of the cumulative areas
of U-238 activity, derived from the areas of Pa-234m activity shown in Table 4-14, results in an
area of soil contaminated above 15 pCi/g equal to 3.1xl06 m2. (This is slightly larger than the
area contaminated by Cs-137 in excess of its free-release limit, which is also 15 pCi/g.) Dividing
this area into the IDE volume produces an average depth of contamination of 14 cm. To be
consistent with the other reference sites that are based on aerial survey data, a value of 5 cm was
selected as the thickness of the contaminated zone. (See descriptions of Reference Sites I, III and
v.)
To construct a distribution of soil concentrations, the uranium was assumed to be commingled
with the cesium (see discussion in Section 4.4.2, above). Minimum and maximum Cs-137
background concentrations at ORR are 0.08 and 4.1 pCi/g, respectively. The geometric mean
of these values, «0.6 pCi/g, is assumed to be the average Cs-137 background at Reference Site
VI. This background was subtracted from the Cs-137 concentrations in Table 4-14 to construct
the Cs-137 distribution shown in Figure 4-15. The U-238 distribution was constructed by
subtracting 1.2 pCi/g (the geometric mean of the minimum and maximum background
concentrations at ORR, 0.97 and 1.4 pCi/g) from the listed concentrations and using log-linear
extrapolation to determine the distribution at lower concentrations. It was further assumed that
U-234, U-235 and U-238 are present in naturally occurring isotopic abundances. Only the U-238
distribution curve is shown in Figure 4-15. Both the Cs-137 and the U-238 curves were
extrapolated to low specific activities to enable the modeling of cleanup to low risks.
Review Draft - 9/26/94
4-69
Do Not Cite Or Quote
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O)
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03
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Figure 4-15
Reference Site VI
Distribution of Contaminated Soil
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0
100
200 300 400
Volume of Soil to be Removed (m**3)
Thousands
Cs-137 U-238
500
Total Contaminated Volume = 3.67E+5 m**3
Additional Nuclides: U-234 and U-235
-------
REFERENCE SITE VII
Reference Site VII is based in part on the soil contamination at the Nevada Test Site (NTS). It
is essential to bear in mind that the following analysis of this reference site, although it makes use
of some of the data that characterize the NTS, cannot be considered to be an analysis of the actual
site. In particular, the predicted impacts refer only to the reference site and cannot be used to
predict the future impacts of the vastly more complicated NTS.
Basis Site Description
The NTS is 65 miles northwest of Las Vegas and occupies an area of 1350 square miles, making
it the largest facility in the DOE complex. The site is surrounded on three sides by the 4,120-
square-mile Nellis Air Force Range. NTS has been the primary site for atmospheric and
underground nuclear weapons testing by DOE. These tests have released large quantities of
radioactive material to surface and sub-surface soil both on and off site. Besides weapons testing,
the site has also been used for radioactive waste disposal. The site includes contaminated sumps,
injection wells, storage tanks, and other on-site facilities. The principal radionuclides at the NTS
include Am-241, Cs-137, H-3, Pu-239, Pu-240, Sr-90, U-234, U-235, and U-238.
Environmental Parameters
The vadose zone at NTS, which consists of soil varying from loamy sand to clean sand, is
approximately 100 meters thick (DOE 90a, pp. 1-3)—this value was assigned to Reference Site
VII. Since no site-specific data were available, representative hydraulic parameters of sandy soils
that are tabulated in the RESRAD references (ANL 93b, DOE 93a) were assigned to the vadose
zone of Reference Site VII. Since site-specific Kd values were also unavailable, representative
Kd's for Cs-137 for sandy soils in the RESRAD tables were assigned to each nuclide at Reference
Site VII.
The average annual precipitation ranges from 10 to 25 cm at different elevations (EPAa). No
site-specific infiltration rate was available, however. Assuming any reasonable value for
infiltration—even as high as 0.5 m/yr—and given the high Kd values for the radionuclides at this
site, the travel time to the aquifer will greatly exceed the maximum 10,000 year assessment
period. Therefore, the lowest infiltration rate, which leads to the longest retention of
radionuclides in the uppermost soil layer, is the most conservative one for assessing the
radiological impacts on future occupants of the site. An infiltration of zero has been suggested
for NTS (DOE 90a, p. 12); this rate was therefore assigned to Reference Site VII.
Review Draft - 9/26/94 4-71 Do Not Cite Or Quote
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Since no infiltration is assumed, the assignment of parameters to the saturated zone is irrelevant
to the present analysis. However, the following data were gathered in the process of
characterizing the site and are provided for future reference. The uppermost water-bearing unit
consists of sand and gravel (DOE 90a, p. 5). Since site-specific parameters were not available,
representative values of the hydraulic conductivity, the exponential parameter (b), and total and
effective porosities of sand and gravel found in the RESRAD tables were assigned to the
saturated zone of Reference Site VII. Since gradients in the aquifer are also unknown, a
conservative value of 0.0001 was assigned to Reference Site VII.
Soil Contamination
Data sources. A draft DOE cost/benefit analysis lists "optimistic", "realistic" and "pessimistic"
values for the areas and volumes of surface soil contaminated with plutonium at various
concentrations (DOE 93d). The volumes corresponding to the "realistic" estimates are shown in
Table 4-15, below. The total volume of soil at or above 10 pCi/g is listed as 2.2xl07 m3, and the
corresponding area as 370 km2, resulting in an average depth of contamination of 5.9 cm. The
isotopic composition of the plutonium is not specified. Since the IDE (SAND 92) indicates that
Pu-239 is the most abundant plutonium isotope in transuranic wastes, the plutonium at NTS is
assumed to be entirely Pu-239. It was further assumed that Am-241 was commingled with the
Pu-239 in a 1:6 ratio, as cited in one of the aerial survey reports (EGG 83).
Table 4-15. Volumes of Soil Contaminated with Pu-239 at NTS
1 Concentrations (pCi/g)
Volume (m3)
>1000
1.8E5
>400
6.0E5
>200
2.0E6
>150
3.0E6
>100
5.1E6
>40
9.4E6
>10 1
2.2E7 1
Although the cost/benefit analysis dealt only with plutonium, aerial surveys show extensive
contamination by other nuclides. As is the case for aerial surveys of other DOE sites, Cs-137 is
the most prominent gamma-emitter detected; it was generally used by EG&G as a marker for the
extent of man-made gamma emitters. Co-60 was used for this purpose in one survey (EGG 85),
for reasons that were not explained. Since the site-wide distribution of Co-60 contamination was
not presented, this nuclide was not included in the present analysis. Due to its relatively short
half-life of 5.3 years, it also presents less of a long-term problem. Large inventories of Eu-152
in the soil at Yucca Flat, one of the nuclear weapons test areas, were reported in a survey
performed in 1978 (EGG 82a). The report did not show isopleths for this nuclide, however.
Curiously, later surveys covering part of the same area made no mention of this
Review Draft - 9/26/94
4-72
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nuclide. It would appear that the aerial surveys were designed to monitor the extent of and
periodic changes in the patterns of contamination, but not to characterize the distribution of the
individual nuclides.
The Cs-137 data was presented in the form of isopleths superimposed on aerial photos of several
areas of the NTS. Most of the isopleths indicate calculated exposure rates at an altitude of 1 m.
Others show counts per second, while a few indicate soil concentrations of Cs-137 in pCi/g,
calculated on the basis of a 5 cm-thick layer of uniform concentration. In the first two instances,
conversion factors enable the calculation of soil concentrations of Cs-137.
Isopleths on the aerial photos of different areas of the NTS did not always correspond to the same
concentration steps. Thus, the isopleths on one map delineated a region with soil concentrations
between 6.8 and 23 pCi/g, while other maps showed activities between 6.6 and 14.3 pCi/g, with
the next isopleth corresponding to 31.5 pCi/g. In such cases, the smallest intervals were used to
characterize the soils. If the activity steps on different maps were identical or nearly the same,
the differences were ignored (6.6 is not significantly different from 6.8) and the areas delineated
by these curves were summed. If the activity intervals were overlapping, as in the above
example, the area falling into the larger interval would be apportioned among the smaller
intervals, using semi-log interpolation. A tabulation of the summed areas is presented in Table
4-16.
Table 4-16. Areas of Cs-137 Contamination at NTS
1 Concentration (pCi/g)
Area (m2)
1-6.7
1.14E8
6.7-14.3
1.24E7
14.3-31.5
2.60E6
31.5-81 1
2.54E5 1
Modeling of contamination. The distribution of Pu-239 was constructed from the data listed
in Table 4-15. The "typical" background concentration of Pu-239 at the NTS is listed as .047
pCi/g (Wai 94). Since this is insignificant in comparison to the listed concentrations, no
correction was made. The distribution of Am-241 was constructed assuming a 1:6 activity ratio
of Am-241 to Pu-239. To construct the distribution of Cs-137, the concentrations listed in Table
4-16 were corrected for the typical site background of 0.72 pCi/g. The thickness of the
contaminated layer is assumed to be the same as was calculated from the Pu-239 data cited
above. The resulting distributions for all three nuclides are illustrated in Figure 4-16.
Review Draft - 9/26/94 4-73 Do Not Cite Or Quote
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o
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Figure 4-16
Reference Site VII
Distribution of Contaminated Soil
3E+4
1E+5 3E+5 1E+6 3E+6 1E+7
Volume of Soil to be Removed (m**3)
Pu-239 Am-241 Cs-137
3E+7
1E+8
Total Contaminated Volume = 5.90E+7 m**3
-------
REFERENCE SITE IX
Reference Site IX is based in part on radiological and environmental data for the contaminated
soil east of the Rocky Flats Plant (RFP). It is essential to bear in mind that the following analysis
of this reference site, although it makes use of some of the data that characterize RFP, cannot be
considered to be an analysis of the actual site. In particular, the predicted impacts refer only to
the reference site and cannot be used to predict the future impacts of the much more complicated
RFP site.
Basis Site Description
The Rocky Flats Plant is an NPL site which is located on an 11-square mile site approximately
16 miles northwest of Denver. Its primary mission was to produce plutonium and other metal
components for nuclear weapons. Environmental contamination at the plant is the result of past
waste disposal practices, spills, and a fire that dispersed plutonium off site. There are 16 OUs at
Rocky Flats where inactive sites are being investigated for possible contamination.
Environmental Parameters
The soil in the vadose zone is assumed to consist of the natural surficial material, which is an
alluvial unit composed of cobbles, coarse gravel, sand and gravely clay (EGG 91, p. 99). This
lithology suggests that a hydraulic conductivity representative of these soils would be relatively
high. Measured hydraulic conductivity data at the site, however, indicate a relatively low
conductivity of 3.3 m/yr (EGG 91, p. 100). A conductivity of IxlO"7 m/s (3.2 m/yr) was assigned
to Reference Site IX.17 Representative RESRAD values of the total porosity, effective porosity
and exponential parameter (b) in sandy soils were also assigned to Reference Site IX. No
infiltration rate for Rocky Flats is available. An infiltration of 0.15 m/yr, representative of the
arid conditions at Rocky Flats, was assigned to the reference site. Kd values representative of the
soils at Rocky Flats, listed in the Environmental Restoration and Waste Management - Five Year
Plan (DOE 90b, p. 152), were assigned to the nuclides at Reference Site IX.
The uppermost water-bearing unit consists of cobbles, coarse gravel, sand and gravely clay, all
in hydraulic connection with a series of sandstones (EGG 91, p. 99). Calculated groundwater
17 It is unclear how representative the measured hydraulic conductivity values are, particularly in light of the wide range of groundwater
velocities and relatively consistent groundwater gradients. Therefore, the representative RESRAD conductivity of a silty-clay loam,
53.6 m/yr, which falls roughly between a silty clay (32.6 m/yr) and a sandy clay (68.4 m/yr), may be more appropriate for use in future
analyses of Reference Site IX. This higher value would make the analysis more conservative. Further information will be gathered
to address this issue.
Review Draft - 9/26/94 4-75 Do Not Cite Or Quote
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velocities in the upper aquifer range from 0.2 to 39 m/yr (EGG 91, pp. 106-112). Since a low
hydraulic conductivity usually results in a more conservative risk assessment, a value of 3.2 m/yr,
the same as for the vadose zone, was assigned to Reference Site IX. The exponential parameter
(b) was assigned the representative values for sand found in the RESRAD tables, while the total
and effective porosities were given the values for coarse gravel. Since no data on groundwater
gradients at Rocky Flats were available, a conservative value of 0.0001 was assigned.
In the stream drainages, groundwater discharges at seeps are commonly found at the contact
between the alluvium and the sandstone (EGG 91, p. 100). Presence of these seeps indicate a
relatively shallow groundwater table, at least over portions of the site. A depth to the water table
of 7.5 feet (2.29 m) was therefore assumed.
Soil Contamination
Data sources. The radionuclides dispersed over the site have been studied over the past two
decades. The primary contaminant is Pu-239, commingled with Am-241 in a 6:1 ratio (Li 94).
Although earlier studies have attempted to characterize the nuclide distributions by soil sample
analyses (Kr 76), a definitive study, employing geo-statistical analyses, was recently presented
by Litaor (Li 93). This study characterized the distribution of Pu-239,240 (and Am-241, by
implication) in the area that lies east of RFP but within the DOE reservation. Samples were taken
from the top 1A inch of soil on 118 plots. Each plot was represented by 25 evenly spaced samples,
composited together and analyzed for plutonium content.
The results of the analysis were presented as a series of isopleths drawn on a map of the study
region. The plutonium concentrations exhibited a log-normal distribution, with a median activity
of 4.31 pCi/g, a geometric standard deviation of 9, and observed minimum and maximum values
of 0.05 and 1453 pCi/g, respectively.
Modeling of contamination. To create a distribution of soil volumes for Reference Site IX, it
was necessary to first determine the area of contaminated zone. Measuring the area within the
7.5 pCi/g isopleth (the highest concentration entirely within the study area) yielded a values of
1.56xl06 m2. For a log-normal distribution with the cited parameters, the soil with activities
above 7.5 pCi/g represents approximately 39% of the total, yielding in a total area of 4
km2—assuming that the pattern of contamination can be extrapolated beyond the DOE property
line.
Review Draft - 9/26/94 4-76 Do Not Cite Or Quote
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The vertical profile of plutonium concentrations has an exponential form. Litaor estimates that
95% of the plutonium is found in the first 15 cm of soil, which is equivalent to a relaxation length
of 5 cm (Li 94). To determine the equivalent depth of a soil layer with a uniform vertical
distribution, we observe that an infinitely deep column of soil with a relaxation length of 5 cm
and a surface concentration of, say, 1 pCi/g contains the same amount of plutonium as a 5 cm-
deep column with a uniform concentration of 1 pCi/g. Assuming this depth of contamination
preserves the total activity in the soil, but underestimates the volume that must be remediated to
meet a given cleanup level. This was therefore the thickness of the contaminated layer adopted
for the radiological risk and impact modeling of Reference Site IX.
To construct the distributions used for the clean-up analysis, the volumes were calculated more
exactly. First, the range of measured concentrations (0.05-1453 pCi/g) was divided into 100
intervals of equal width on a logarithmic scale. Next, for each interval, the area of soil having
Pu-239 surface concentrations in that interval was calculated, based on the total area and the log-
normal distribution. Next, the vertical exponential concentration profile was used to calculate
the concentrations at successively greater depths under each of the 100 elements of area. In this
manner, a three dimensional mathematical map was developed which enabled the construction
of the distribution of Pu-239 shown in Figure 4-17. The distribution of Am-241 was constructed
on the assumption that the two nuclides were found in a 6:1 ratio of specific activities.
Litaor reviewed earlier studies of soil contamination in the Rocky Flats area (Li 93). He observed
that the characterization of off-site plutonium contamination had been based on a paucity of data
and lacked a rigorous mathematical treatment. He then noted that his data fail to support earlier
assumptions about off-site contamination, concluding that the extent of such contamination and
its impact on the local inhabitants had been overestimated. Because of these doubts, the earlier
data were not used in characterizing Reference Site IX.
Aerial surveys, using Nal detectors, and in-situ surveys, employing a vehicle-mounted high-
purity germanium (HPGe) detector, have also been performed at the RFP site (EGG 82b, EGG90,
EGG91). The detection system used in the in-situ survey, although more restricted in its
movement, characterizes soil distributions more accurately than the aerial survey. Its proximity
to the surface—surveys were taken with the detector one meter and 7.5 m above the
surface—gives it a far better spatial resolution, while its high energy resolution enables it to
detect and measure the 60 keV gamma ray of Am-241 in the presence of a background radiation
field. The distribution of Am-241 in the soils east of RFP, as characterized by the in-situ
Review Draft - 9/26/94 4-77 Do Not Cite Or Quote
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Figure 4-17
Reference Site IX
Distribution of Contaminated Soil
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E
0.01
0
100
200 300 400 500 600
Volume of Soil to be Removed (m**3)
Thousands
Pu-239 Am-241
700
800
900
Total Contaminated Volume = 8.00E+5 m**3
-------
survey, confirmed Litaor's analysis of the soil sample data. Since Am-241 and plutonium are
known to be commingled (Pu-241 decays to Am-241 with a half-life of 14.4 years), Am-241 can
usually serve as a marker for plutonium.
The aerial survey data showed a somewhat different distribution of Am-241 in the area east of
RFP, with the isopleths shifted to the west. Because of the much lower resolution and sensitivity
of these measurements as compared to the in-situ data, the latter data were not used in the present
analysis.
Other areas of the RFP site, including the industrial area and the old landfill, were studied in the
course of the aerial and/or in-situ surveys. The industrial area contains little exposed soil, and
thus is not a good candidate for the present study. No Am-241 was detected at the old landfill
by either the aerial or the in-situ surveys. The in-situ survey showed a contaminated area of
roughly 10,000 m2 with maximum U-238 concentrations of 13 pCi/g. This constitutes a minor
site in terms of the present study; since it is about one mile away from the area of plutonium
contamination east of the RFP, it is not properly part of the same site.
REFERENCE SITE X
Reference Site X is based in part on radiological and environmental data on soil contamination
at the Paducah Gaseous Diffusion Plant (PGDP). It is essential to bear in mind that the following
analysis of this reference site, although it makes use of some of the data that characterize the
PGDP, cannot be considered to be an analysis of the actual site. In particular, the predicted
impacts refer only to the reference site and cannot be used to predict the future impacts of the
much more complicated PGDP site.
Site Description
The PGDP is located on a 750-acre site in Paducah, Kentucky, including 74 acres of process
buildings. Its primary mission is the separation of uranium isotopes through gaseous diffusion.
The process produces enriched uranium for nuclear fuel in commercial nuclear power plants and
for military purposes. The US Enrichment Corporation has operated the site since 1993 under
a lease from DOE.
There are two waste burial areas at Paducah, holding mainly uranium. For the purpose of
environmental restoration, the site has been divided into 95 solid waste management units.
Review Draft - 9/26/94 4-79 Do Not Cite Or Quote
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Environmental Parameters
The vadose zone at the PGDP consists of sandy and silty clay (DOE 92e, p. 3-21), with a
hydraulic conductivity that ranges from 0.0035 to 210 m/yr (DOE 92e, p. 3-30). The geometric
mean of 0.86 m/yr was adopted for Reference Site X. The effective porosity of the soil at
Paducah is estimated at 0.2 (DOE 92e, p. 3-36), which was adopted for the reference site. Since
no site-specific data for the exponential parameter (b) and total porosity were available,
representative values of these parameters in sandy, silty clay soils were adopted for the vadose
zone of Reference Site X. Because no representative values for sandy, silty clay are tabulated
in the RESRAD references (ANL 93b, DOE 93a), the arithmetic means of the listed values for
sandy clay and silty clay were used. Representative RESRAD Kd's for clay soils were assigned
to each nuclide at Reference Site X.
The precipitation rate at Paducah is 1.28 m/yr, with an evapotranspiration rate of 0.75 m/yr and
a combined runoff and infiltration rate of 0.53 m/yr (DOE 92e, p. 3-2). These data were used to
calculate an infiltration of 0.50 m/yr for Reference Site X, using the method outlined for the
RESRAD code (ANL 93b, p. 9-4).
The saturated zone consists of alluvial deposits of sandy and silty clay overlying a gravel and
sand regional aquifer (DOE 92e, p. 3-31). The hydraulic conductivity of this aquifer ranges from
315 to 3,150 m/yr. The geometric mean value of 1,010 m/yr was assigned to Reference Site X.
The effective porosity is estimated at 0.2 (DOE 92e, p. 3-36)—this value was assigned to
Reference Site X. The hydraulic gradient at Paducah ranges from 0.00013 to 0.00138, with an
average value of 0.00075 (DOE 92e, pp. 3-37 to 3-38). The average value was assigned to
Reference Site X. Since no site-specific data for the exponential parameter (b) and total porosity
were available, representative RESRAD values of these parameters in gravel and sand were
assigned to Reference Site X.
Soil Contamination
Data sources. Although a Phase II Site Investigation and a Public Health and Ecological
Assessment have been performed at this site (DOE 91), the radionuclide contamination of on-site
soils has not been characterized. The soil sampling program was directed at assessing the
potential for off-site contamination; therefore, samples were taken at the peripheries of waste
management units (WMUs) or in areas of known contamination. These data do not enable the
development of a contamination profile of the soil. One of the reports cautions that the sample
assays are likely to produce underestimates of on-site contamination and are not sufficient for a
Review Draft - 9/26/94 4-80 Do Not Cite Or Quote
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baseline risk assessment. Other WMUs constitute low-level waste burial grounds and are thus
not within the scope of the present report. Samples were taken throughout one unit: WMU-1,
an oil landfarm. Buried metal has been detected at this site, raising the possibility that it, too,
might be more properly classified as a waste disposal area. For lack of a better candidate, this
site, with an area of approximately 8,900 m2 and an estimated volume of 16,300 m3, is used to
typify the pattern of soil contamination at the PGDP.
The 1993 IDE lists a total contaminated soil volume of 72,000 m3 at the PGDP.
Modeling of contamination. Radionuclide assays have been performed on 13 soil samples
taken at various depths from six borehole locations at WMU-1. If it is assumed that the
radionuclide concentrations in this soil exhibit a log-normal distribution and that the sample
locations were randomly chosen, it is possible to use the assay results to construct a profile of soil
contamination for each radionuclide in this subunit. If it is further assumed that this subunit
typifies the pattern of soil contamination in the soil volume listed in the IDE, it is possible to
characterize the soil contamination at the PGDP.
Radiological assays were performed on six core samples collected at WMU-1. Three of those
cores, which reached a depth of 6 feet, were subdivided into three sections, each 2 feet long. The
remaining three cores were analyzed as single samples. Thus, a total of 11 samples were assayed.
The primary nuclides detected were Tc-99, U-238 and U-234. Nine assays for Tc-99 were
performed. (It is assumed that the samples for which no specific activity is listed were not
assayed for that nuclide.) Four samples were assayed for both U-238 and U-234.
Radionuclide distributions of uranium and Tc-99 at Reference Site X were constructed as follows.
Each concentration was weighted by the core length of the sample or sub-sample that it
represents. Since the specific activities of the two uranium isotopes did not appear to differ
significantly, the average of the two activities was calculated for each sample and used in the
present analysis. Log-normal distributions of Tc-99 and the two uranium isotopes were
constructed, using the calculated values of the geometric mean and geometric standard deviation,
which are listed below. Four values of background soil activities of U-238 for Kentucky were
listed in Myr 81; the weighted average specific activity, 1.0 pCi/g, was subtracted from each
value on the uranium distribution curves. Although the soil contaminants at PGDP most likely
include U-235, no assay results were given. That nuclide was therefore not included in the
distributions at Reference Site X. Figure 4-18 depicts the radionuclide distributions at Reference
Site X.
Review Draft - 9/26/94 4-81 Do Not Cite Or Quote
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Figure 4-18
Reference Site X
Distribution of Contaminated Soil
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1E+1
1E-1
1E-2
x
03
5 10 20 50 100
Volume of Soil to be Removed (m**3)
Thousands
Tc-99 U-238
200
500
1,000
Total Contaminated Volume = 7.06E+5 m**3
Additional Nuclide: U-234
-------
Table 4-17. Statistical Analysis of Radiological Assays of Soil Samples
Nuclides
Tc-99
U-238 & U-234
No. of
Samples
9
4
Concentration (pCi/g)
Geometric Mean
3.08
4.09
Maximum
640
14.5
Minimum
0.6
1.5
Geometric OD
15.4
2.56
An earlier RESRAD analysis of the peak risk showed that the principal Tc-99 pathway was via
crops raised in the contaminated soil. Since the root zone is assumed to consist of the top 90-cm
soil layer, any technetium deeper than this would be inaccessible. Although Tc-99 contamination
was found as deep as six feet (1.8 m), the highest concentrations were found in the top 12 inches
(30.5 cm). It was therefore postulated that all of the Tc-99 activity is in the top 30.5 cm of soil
at Reference Site X. The principal path for uranium, however, is via the groundwater.
Postulating that the uranium at Reference Site X was uniformly distributed in the upper 1.8 m of
the soil (the maximum depth of the boreholes) results in a shorter average travel time to the
aquifer, and is therefore conservative.
Although this is the best characterization that can be performed using the available data, it is
probably not an accurate description of the contamination pattern in WMU-1, nor does the pattern
of this subunit represent the site-wide pattern of contamination at the PGDP.
REFERENCE SITE XII
Reference Site XII is based in part on radiological and environmental data for the Boeing
Michigan Aeronautical Research Center (BOMARC) missile accident site. It is essential to bear
in mind that the following analysis of this reference site, although it makes use of some of the
data that characterizes BOMARC, cannot be considered to be an analysis of the actual site. In
particular, the predicted impacts refer only to the reference site and cannot be used to predict
future impacts of the much more complicated BOMARC site.
Basis Site Description
The BOMARC missile accident site occupies approximately 218 acres just east of Ocean County
Highway 539 in Ocean County, New Jersey. It lies about 11 road miles east of McGuire Air
Force Base and is contained in the Fort Dix Military Reservation on land leased to the Air Force.
In 1960, an explosion and fire occurred in BOMARC Missile Shelter 204. A substantial amount
of plutonium was released from Shelter 204 during the incident. The facility was deactivated in
1972, but remains under Air Force lease and jurisdiction.
Review Draft - 9/26/94
4-83
Do Not Cite Or Quote
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Environmental Parameters
The soil in the vadose zone at BOMARC is a well-sorted, medium-grained, quartz sand
containing minor amounts of gravel, clay, silt, and peat (ET 92, p. 2-8). In the absence of site-
specific data, representative values of the hydraulic conductivity, exponential parameter (b), and
total and effective porosities of sandy soils tabulated in the RESRAD references were assigned
to the vadose zone of Reference Site XII. The depth to the water table ranges from 3.7 to 17
meters (ET 92, p. 2-9). The geometric mean of this range, 7.8 meters, was assigned to Reference
Site XII. Since no Kd values were available, each radionuclide was assigned the geometric mean
Kd value in sand tabulated in the RESRAD handbook.
The precipitation is 1.10 m/yr, with an evapotranspiration rate equal to 42% of the precipitation
(0.46 m), the remaining precipitation being split between runoff and infiltration. Using the
method outlined for the RESRAD code (ANL 93b, p. 9-4), the infiltration for Reference Site XII
was calculated to be 0.54 m/yr.
The uppermost water-bearing unit consists of sand (ET 92, p. 2-7), with hydraulic gradients in
the range of 0.002 to 0.009. A value of 0.002, the gradient of the Cohansey Sand layer (ET 92,
p. 2-10), was assigned to the aquifer of Reference Site XII. Other hydrogeological parameters
were assigned values representative of sandy soils that are tabulated in the RESRAD references.
Soil Contamination
Data Sources. A Remedial Investigation/Feasibility Study (RI/FS) was performed as part of the
Installation Restoration Program at BOMARC in 1992. Extensive sampling and analysis
activities were undertaken as part of the RI/FS, and results were available for surface and
subsurface soils, as well as an in-situ gamma spectroscopy survey of the site.
The radionuclides of interest at the site were selected on the basis of the site's history. The
contamination at BOMARC consists of weapons-grade plutonium. The primary isotope is Pu-
239, but small quantities of Pu-238, Pu-240, Pu-241 and Am-241 (from beta decay of Pu-241)
are also present. Pu-239 serves to represent the plutonium isotopes in this analysis. Am-241 has
been detected by the HPGe gamma survey: its specific activity was estimated to equal one sixth
of the Pu-239 activity (ET 92, p. 4-93).
Review Draft - 9/26/94 4-84 Do Not Cite Or Quote
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The radioactive contamination is not distributed evenly over the site but occurs in discrete "hot
spots", which in several instances, have been found to be a single particle, presumably containing
plutonium oxide (ET 92, p. 1-13). Thus, radiation measurements can vary over a small area.
The results of the in-situ survey were presented as a series of isopleths drawn on a map of the site
(ET 92, p. 4-69). These isopleths delineate areas of different surface activities, in units of |iCi/m2.
Because of the irregular distribution of contamination at the site, these data are not an accurate
measure of the radionuclide concentrations in the soil. They do, however, provide a good
measure of the total contaminated area, which was determined by measuring the area of the map
enclosed by the outermost isopleth, which corresponds to a Pu-239 activity of 0.2 |iCi/m2.
Modeling of contamination. Six sampling stations were used to determine the depth profiles
of contamination at the BOMARC site. Unfortunately, these samples only characterized the top
18 inches of soil, even though contamination was discovered at depths of 10 feet for several
borehole samples. Because of this limitation, new depth profiles were conducted for each of the
six sampling stations as well as each of the 26 borehole locations.
At each location, the Pu-239 concentration was measured at various depths. The volume of the
contaminated soil for each depth increment was calculated, based on the surface area of
contamination determined by the in-situ gamma survey.
Several small areas identified by the HPGe survey were not sampled for depth analyses, although
surface soil samples were collected from each location. For these areas the contamination was
assumed to be contained in the top 6 inches (15 cm) of soil and the volume of contaminated soil
is calculated based on this assumption. The Pu-239 concentration for that volume of soil was set
equal to the concentration found in the surface soil sample representing that area.
These volumes of soil were used to produce the distributions shown in Figure 4-19. The total
volume of soil for the site was divided by the total area of the site to estimate the average depth
of contamination on the site.
Quality of data. The characterization of the plutonium contamination in the BOMARC soils
appears to be comprehensive, including over 250 contaminated soil samples and 30 randomly
Review Draft - 9/26/94 4-85 Do Not Cite Or Quote
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Figure
4-19
Reference Site XII
Distribution of Contaminated Soil
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x
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100
10
0.1
0.01
500
1,000 2,000 5,000
Volume of Soil to be Removed (m**3)
Pu-239 Am-241
10,000
20,000
Total Contaminated Volume = 1.76E+4 m"
-------
selected background samples. The individual sample results were included in the report along
with a discussion on possible sources of error. The largest single source of error in the
measurements was the non-homogeneous nature of the contamination. Loss of samples was also
identified as a potential error.
The areal extent of contamination on the site was determined based on results of the HPGe
survey. Over 400 measurements were made to produce the isopleths used in this analysis. The
report includes a discussion on the limitations and detection capabilities of the method. Once
again, the largest single source of error in the measurements was determined to be non-
homogeneity of the contamination.
REFERENCE SITES XIIIA. -B & -C
Three Reference Sites, designated XIIIA, XIIIB and XIIIC, represent DU sites in the Northeast,
Southeast and Southwest, respectively. The area, volume and contamination profile of the soils
at these sites are based in part on the soil contamination at the Aberdeen Proving Ground (APG).
It is essential to bear in mind that the following analyses of these reference site, although they
make use of some of the data that characterize the APG, cannot be considered to be analyses of
the actual site, nor of any other particular DU site. In particular, the predicted impacts refer only
to the reference sites and cannot be used to predict the future impacts of the much more
complicated APG or other actual site.
Environmental Parameters
The environmental parameters that characterize these reference sites are discussed under the sub-
heading "Generic Reference Site Parameters" on Section 4.4.1, above.
Basis Site Description
The processing of natural uranium to obtain uranium enriched in the fissile isotope uranium-235
results in an abundance of waste or "tails" referred to as depleted uranium (DU). The high
density and low specific activity of depleted uranium make it useful for several applications, one
of which is military munitions.
The military uses depleted uranium in armor-penetrating weapons. The Army has developed and
refined the design of these munitions based on "soft" and "hard" testing. Soft testing is conducted
to assess and refine the accuracy of the munitions. The tests are performed on outdoor firing
ranges where the depleted uranium round is fired at the target, or typically a sand-filled
Review Draft - 9/26/94 4-87 Do Not Cite Or Quote
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catch box, located several kilometers from the gun. Hard testing is conducted to evaluate and
refine the destructive capability of the munitions. In hard testing, either actual munitions or scale
mockups are fired at an armor-plated target.
All branches of the Department of Defense test depleted uranium munitions at several proving
grounds around the country. A total of seven military sites have been used for conducting
munitions testing. The Army's Ballistic Research Laboratory (BRL) and Combat Systems Test
Activity (CSTA) facilities at the Aberdeen Proving Ground in Aberdeen, Maryland conduct both
hard and soft testing. The Army also conducts soft testing at the Yuma Proving Ground in Yuma,
Arizona and Jefferson Proving Ground in Madison, Indiana. Once every two or three years, the
Army conducts an open-air hard test firing at the Nevada Test Site. The Air Force directs
operation of an outdoors hard-target range in Las Vegas at the Nellis Air Force Base and soft-
target testing at the Eglin Air Force Base in Florida. Both soft- and hard-testing are conducted
by the Navy at China Lake, California. The Navy is also in the process of cleaning up a retired
hard-testing site in Virginia known as Dahlgren. APG is considered to represent the bounding
case within this category based on the fact that hard-test firing was conducted outdoors prior to
1980, and since it conducts the greatest number of test firings.
The Army's CSTA weapons testing program at Aberdeen Proving Ground has included outdoor
firing of depleted uranium projectiles at two locations known as the Ford's Farm range and the
B-3 range. Both areas are east of the Bush River, with the B-3 range about 6 km northeast of
Ford's Farm.
Ford's Farm Range. From the late 1960's to 1980, the Ford's Farm area was used as an open-air
hard-target testing site. As of early 1978, approximately 1600 kg of DU in the form of projectiles
were fired 200 m into various types of armor (metal) targets. When the DU projectiles hit the
plates, the DU ignites, reducing it to sizeable fragments and a particulate cloud (DU dust). The
cloud settled on the ground and nearby vegetation, with the location of the deposition dependent
on wind and weather conditions.
B-3 Range. The B-3 range is the site where the outdoor soft-target testing of munitions are
performed. The B-3 range encompasses a large land area extending approximately 8000 m
downrange from the firing position. On the range, projectiles are fired for accuracy at soft targets
positioned 1000, 2000, 3000, and 4000 m downrange. These projectiles pass through the targets
intact and usually burrow into the ground at locations beyond the target;
Review Draft - 9/26/94 4-88 Do Not Cite Or Quote
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fragmentation into visible pieces is possible if projectiles hit trees or rocks either above or below
ground. The intact projectiles or fragments come to rest on the surface or buried underground.
A limited environmental survey, including the collection and analysis of the soil samples, was
conducted to determine the location of DU around the Ford's Farm and B-3 target areas. This
survey only assessed soils believed to contain the highest levels of DU contamination based on
(1) an estimate of where most projectiles were landing at the B-3 range and (2) an aerial survey
map of the Ford's Farm range and surrounding areas indicating the approximate locations of
elevated radiation levels.
The study made no effort to estimate the natural background levels of uranium in an unaffected
area outside the Aberdeen Proving Ground. However, two samples were collected from a
location on the Proving Ground that was thought to be unaffected as a comparison with samples
taken from the firing range areas. An average uranium concentration of 2.0 |ig/g, with an
estimated analytical error of ± 35%, was calculated using these reference area samples. This
value coincides with the average uranium concentration of 1.8 ppm in U.S. soils, as cited in
NCRP Report 94.
Modeling of contamination. Using the above-cited environmental survey data, the total area
and volume of depleted uranium soil contamination at the two firing ranges were estimated. This
estimate incorporated the following assumptions:
• Analytical results related to a specific grid point were used as the average uranium
concentration of soils within the entire grid area (38 m x 38 m).
• The APG soil measurements of uranium that indicated less than 2.7 jig/g were
considered to be below background levels, and those grid point sample results
were not included in the area/volume calculation.
• Soils below a depth of 7.6 cm were not considered to be contaminated.
• DU was assumed to have the isotopic ratios listed in Table 4-18, below.
Review Draft - 9/26/94 4-89 Do Not Cite Or Quote
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Table 4-18. Relative Isotopic Masses (%) of Natural and Depleted Uranium
Isotope Natural Uranium Depleted Uranium
U-238 99.2739 99.75
U-235 0.724 0.25
U-234 0.0057 0.0005
Using these assumptions, the areas and volumes of depleted uranium soil contamination was
calculated as follows:
Location Area (m2) Volume (m3)
Ford's Farm Range 38,990 2,970
B-3 Range 2.890 220
TOTAL 41,880 3,190
Figure 4-20 shows the radionuclide distributions at Reference Site XIII.
REFERENCE SITES XVIA. -B & -C
Reference Sites XVIA, XVIB, and XVIC are based in part on radiological data from commercial
nuclear power plants. It is essential to bear in mind that the following analysis of these reference
sites, although it makes use of some of the data that characterize these plants, cannot be
considered to be an analysis of the actual sites. In particular, the predicted impacts refer only to
the reference sites and cannot be used to predict the future impacts of the more complicated and
highly varied nuclear plants in general, nor of any one plant.
Soil Contamination
Data sources. These reference sites are based on a composite of the patterns of soil
contamination at six commercial nuclear power plants, as reported by Abel et al. (Ab 86). Soil
samples were collected at each of the six plants, each sample covering an area of 0.1 m2 but
varying in depth from 3 cm to 15 cm. Deeper samples were subdivided into stratified layers. The
sampling plan was neither systematic nor consistent from plant to plant. At several plants,
samples were taken within the exclusion area boundary in different compass directions from the
reactor. In addition, biased samples were collected in areas of known or suspected
contamination.
Review Draft - 9/26/94 4-90 Do Not Cite Or Quote
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Figure 4-20
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Reference Site XIII
Distribution of Contaminated Soil
100
10
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0.01
0
1 2
Volume of Soil to be Removed (m**3)
Thousands
U-238 U-235 U-234
Total Contaminated Volume = 2.60E+3
m**3
-------
The description of the sampling plan by Abel et al (Ab 86) also varies from plant to plant. In
some cases, both the sample location and the rationale for its selection are stated. In others, only
the location is given, and in still others no information on the sampling plan is presented. For all
samples, the depth of the soil layer and the concentrations of up to 25 radionuclides are listed.
Modeling of contamination. An examination of the concentration data indicated that the
following five nuclides which had been detected at all six plants were possible causes of concern:
Co-60, Cs-134, Cs-137, Mn-54 and Sb-125. This list was further reduced after comparing the
site-specific RESRAD risk factors, typical soil concentrations and radioactive half-lives.
(Relatively short-lived nuclides will have largely decayed away during the time between the cold
shut-down of a given plant and the release of the site following decommissioning.) Co-60 and
Cs-137 were thus selected as principal nuclides of concern in the analysis of the sites. (Abel et
al. cite Co-60 as the limiting nuclide.)
Based on the available information on the sampling plan, biased on-site samples and remote off-
site samples were eliminated from the characterization scheme. The data from the remaining
sample analyses for the six plants were pooled. Each concentration measurement was weighted
by the thickness of the soil layer from which it was collected, all samples being assumed to
represent equal areas. Frequency histograms were constructed for Cs-137 and Co-60 by grouping
the individual readings into six or seven concentration ranges.
The thickness of the contaminated zone was assumed to be 15 cm, the maximum depth of the soil
samples. The volume was calculated on the basis of requests for on-site disposal at nine other
nuclear power plants, made to the NRC in compliance with 10 CFR 20.302 (John 94). The
average volume of soil at these nine plants was 573 m3. For the purpose of the present analysis,
it was assumed that these requests referred to soils contaminated above the NRC's free release
limits, which are 8 pCi/g for Co-60 and 15 pCi/g for Cs-137 (John 94). Using the sum of
fractions rule with the frequency histogram for Reference Site XVI, it was calculated that 54%
of the sampled soils at the six plants studied by Abel et al were above the free release limit. The
total sampled volume was therefore calculated to be 1,060 m3. The distribution of the two
nuclides at Reference Site XVI is illustrated in Figure 4-21. The curves were extrapolated to low
concentrations to enable the modeling of cleanup to low risk levels.
Review Draft - 9/26/94 4-92 Do Not Cite Or Quote
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Figure 4-21
Reference Site XVI
Distribution of Contaminated Soil
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x
03
0 100 200 300 400 500 600 700 800 900
Volume of Soil to be Removed (m**3)
Co-60 Cs-137
1,000 1,100 1,200
Total Contaminated Volume = 1.06E+3 m**3
-------
Although the data on the basis sites for Reference Site XVI is admittedly sparse, little or no better
data is believed to exist. Operating nuclear power plants are not required characterize the
radioactive contamination of their soil; it is therefore unlikely that they would do so. Since no
sites of decommissioned plants have yet been released, and since the buildings and equipment
at these sites pose by far the greater radiological hazard, the soils on these sites have not been
extensively studied.
REFERENCE SITES XVIIIA. -B & -C
Reference Sites XVIIIA, XVIIIB, and XVIIIC are based in part on radiological data from the
Cintichem, Inc. reactor facility. It is essential to bear in mind that the following analysis of these
reference sites, although it makes use of some of the data that characterize this reactor, cannot
be considered to be an analysis of the actual site. In particular, the predicted impacts refer only
to the reference sites and cannot be used to predict the future impacts of the more complicated
reactor site, nor of any other site of this type.
Soil Contamination
Data sources. These reference sites are based on a reference research reactor. The pattern of
soil contamination is based on data from the Cintichem, Inc. reactor facility in Tuxedo, N.Y.,
which is currently undergoing decommissioning. This facility was constructed as a research
reactor but was subsequently converted to the production of radioisotopes. The pattern of soil
contamination at this site may therefore not be typical of that at a research reactor; however, soil
contamination data were not available for any other research reactor.
Modeling of contamination. The area and thickness of the contaminated zone were given in the
results of a RESRAD analysis performed by Cintichem (Cin 92). The area was initially assumed
to be 5,400 m2. In a subsequent comment, Cintichem estimated that the actual area was 61% of
this value, or approximately 3,300 m2. Cintichem assumed the thickness to be 15 cm, which,
combined with the reduced area, yields a volume of approximately 500 m3. Scant data on the
distribution of radionuclides are found in the Cintichem report. The largest volume of soil, which
is in the area of the underground exhaust system, is characterized as having equal concentration
of Cs-137, Sr-90 and Ce-144 with peaks "possibly reaching the 10,000 pCi/g level." Since the
facility has been shut down since February, 1990, Ce-144, which has a radioactive half-life of
284 days, is no longer a significant problem. Cs-137 and Sr-90 were therefore assumed to be the
nuclides of concern in the present analysis (Cintichem's RESRAD analysis was limited to Sr-90).
Review Draft - 9/26/94 4-94 Do Not Cite Or Quote
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The distributions of the two nuclides at Reference Site XVIII were constructed by assuming that
both concentration had truncated log-normal distributions with a maximum (99.9 percentile)
value of 10,000 pCi/g and a minimum (0.1 percentile) of 0.5 pCi/g. (Cs-137 concentrations of
less than 0.5 pCi/g are in the range of global fallout (Cin 92)). These distributions are illustrated
in Figure 4-22.
REFERENCE SITES XXA. -B & -C
Reference Sites XXA, XXB, and XXC are based in part on radiological data from the Babcock
and Wilcox plant at Apollo, Pennsylvania. It is essential to bear in mind that the following
analysis of these reference sites, although it makes use of some of the data that characterize this
plant, cannot be considered to be an analysis of the actual site. In particular, the predicted
impacts refer only to the reference sites and cannot be used to predict the future impacts of the
more complicated plant site, nor of any other site of this type.
Soil Contamination
Data sources. Reference sites XXA, XXB, and XXC are based on a reference uranium fuel
processing and fabrication plant. The soil contamination was characterized on the basis of data
for the Apollo plant. The plant has been decommissioned and site remediation is currently under
way. The site is listed in the NRC's Site Decommissioning Management Plan (SDMP) (NRC 93).
Although moderate concentrations of Tc-99 (3-160 pCi/g) have been reported in one portion of
the site, the principal nuclides of concern are the isotopes of uranium. Soil and building materials
with specific activities of total uranium in excess of 2,000 pCi/g had been disposed of as low-
level waste. However, uranium soil concentrations up to that level remained at the beginning of
the recent cleanup phase, which is documented in the quarterly progress reports for 1992 (B&W
92a, B&W 92b, B&W 93a, B&W 93b).
The progress reports cite volumes of "potentially contaminated" soil in various portions of the
site, but do not report the distribution of concentrations. Although the total volume of
"potentially contaminated" soil is stated to be 1,410,800 ft3 («40,000 m3), elsewhere the reports
observe that sampling of the excavated soils reveals much of it to be below the NRC's free release
limit of 30 pCi/g total uranium. The reports also state that approximately 17 m3 of soil, having
uranium activities of 3,000 to 9,000 pCi/g, had been shipped to a low-level waste repository.
Review Draft - 9/26/94 4-95 Do Not Cite Or Quote
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Figure 4-22
Reference Site XVIII
Distribution of Contaminated Soil
100
200 300 400
Volume of Soil to be Removed (m**3)
Cs-137
500
600
Total Contaminated Volume = 5.85E+2 m**3
Additional Nuclide: Sr-90
-------
The most current information about this site was obtained in a telephone conversation with Don
Sqarlatta, a health physicist employed by Babcock and Wilcox, on August 25, 1994. Sqarlatta,
who is supervising the cleanup activities, reported that all soil contaminated with 30 pCi/g or
more of total uranium has been shipped off site. The total volume shipped during the recently
completed cleanup phase was 773,100 cubic feet. This is approximately one-half the volume of
potentially contaminated soil cited in the B&W reports and about twice the volume cited in the
SDMP, which is 380,000 ft3. The volume cited by Sqarlatta is thus quite consistent with the other
sources.
The inventory of radioactive waste, which consists primarily of soil, crushed rock and other
excavated materials, but also includes some rubble from demolished buildings, is listed in Table
4-19. The volumes of waste with uranium contamination between 30 and 200 pCi/g of total
uranium activity were reported by Sqarlatta. The volume above 2,000 pCi/g, which had been
removed prior to the most recent cleanup phase, was taken from B&W 92a.
Table 4-19. Uranium Contamination at Reference Site XX
Concentration (pCi/g)a
Volume (m3)
>2,000
17
200-2000
130
100-200
2888
50-100
8750
30-50
10,120
a Sum of 3 specific activities
Modeling of contamination. Sqarlatta stated that the uranium on site had an average enrichment
of 3% (by weight) of U-235. Actual isotopic ratios of U-238, U-235 and U-234 were not
available at the present time. Based on the isotopic ratios of depleted uranium, which is the
material left over from the enrichment process, it was inferred that the mass ratios of the three
isotopes U-238:U-235:U:234 were 0.97:0.03:0.0031, resulting in relative activities of
0.14:0.028:0.83. The total uranium activities listed in Table 4-19 were apportioned among the
three isotopes according to these ratios. The natural background concentration of U-238 in the
vicinity of Blairsville, Pennsylvania, the nearest cited location to the Apollo site, has an average
value of 1.0 pCi/g (Myr 81). The natural background concentrations of the three uranium
isotopes were subtracted from their calculated activities to construct a radionuclide distribution
for Reference Site XX. To enable the modeling of cleanup to very low risk levels, the
extrapolated volume with a specific activity > 1 pCi/g above background of total uranium was
calculated by log-log extrapolation of the tabulated data. The resulting distribution curves are
illustrated in Figure 4-23.
Review Draft - 9/26/94 4-97 Do Not Cite Or Quote
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VO
oo
Figure 4-23
Reference Site XX
Distribution of Contaminated Soil
D)
CD
O
CD
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O
Q.
C
O
I
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0)
o
1,000
100
10
CD
O
o
I
O
fit
O
X
CO
1E+1
1E+2 1E+3 1E+4
Volume of Soil to be Removed (m**3)
U-238 U-235 U-234
1E+5
1E+6
Total Contaminated Volume = 4.94E+5 m**3
-------
The area of contamination is assumed to be equal to the site area, which is 5 acres or
approximately 20,000 m2. The average thickness of the contaminated zone is 36 cm if only the
soil volume above 30 pCi/g is considered. This was the thickness used in calculating the
population impacts. For the purpose of calculating the risk to an individual, a more conservative
value of 1 m was used. Both values are listed in Table 4-6.
REFERENCE SITES XXIA. -B & -C
Reference Sites XXIA, XXIB, and XXIC are based in part on radiological data from the
Molycorp, Inc. plant in Washington, Pennsylvania. It is essential to bear in mind that the
following analysis of these reference sites, although it makes use of some of the data that
characterize this plant, cannot be considered to be an analysis of the actual site. In particular, the
predicted impacts refer only to the reference sites and cannot be used to predict the future impacts
of the more complicated plant site, nor of any other site of this type.
Soil Contamination
Data sources. These reference sites represent NRC-licensed rare earth extraction facilities.
However, the soil contamination data are taken from the Washington, Penn. plant, which is a rare
metal smelting facility for which extensive soil characterization studies have been performed.
The SDMP (NRC 93) cites the area of the site as 7 hectares (70,000 m2); however, the portion
of this site selected for the detailed study of Th-232 soil concentrations had an area of 13,800 m2,
as measured on a map of the study area (Wr 90). This area included eight holding ponds, which
are treated as soil surfaces for the purpose of the present analysis.
Wrenn et al. (Wr 90) drilled 28 boreholes over the study area that appear to be randomly
distributed over the ground surface—excluding the ponds, which have a combined area of
approximately 2,000 m2. Two additional holes were drilled, each five feet (1.5 m) from one of
the original holes, to check the spatial variability of the soil concentrations. Each hole was drilled
to a depth of 19 feet (5.8 m) or to bedrock, whichever was reached first. Radiation exposure rates
were measured at 6-inch (15 cm) intervals from the top to the bottom of each hole, using a Nal
scintillation detector that had been calibrated against a PIC exposure meter in the above-ground
radiation field at the Molycorp site. The exposure measurements were then converted to
concentrations of Th-232 (assumed to be in equilibrium with its daughter products), using
published conversion factors. Because the conversion factors were based on a 47t geometry (i.e.,
that the detector was completely surrounded by soil), concentrations were calculated only at
depths of 1.5 ft (46 cm) or more, since the effect of the open hole above the detector becomes
Review Draft - 9/26/94 4-99 Do Not Cite Or Quote
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negligible at this depth. Two more holes were drilled at uncontaminated locations in the vicinity
of the site to determine the local soil background radiation levels.
Modeling of contamination. Upon comparing the readings in the two pairs of adjacent
boreholes, Wrenn etal. concluded that the spatial variability was so great that the borehole data
cannot be used to construct a three-dimensional map of soil concentrations. In the present
analysis, however, the distribution of Th-232 in the soils of the study area was characterized by
the frequency distribution of the concentrations at various depths in the 30 on-site boreholes.
(Since the readings in the two pairs of adjacent boreholes did differ, they were treated as
independent locations.) A frequency histogram was constructed by grouping the individual
readings into nine concentration ranges. In addition, since the solid angle subtended by the
contaminated soil in the uppermost part of the borehole gradually changes from 2ft to 4ft with
increasing depth, it was possible to estimate the concentrations in the upper layers based on the
geometry the concentrations in the upper 1.5-foot portions of the boreholes.
Wrenn et al. had determined Th-232 concentrations by multiplying each calculated exposure
value by a conversion factor. The resulting value thus included the natural soil background
radiation, which produced an exposure rate equivalent to 4.06 pCi/g of Th-232 (Wr 92). It was
necessary to subtract this background value from each calculated concentration. The
concentration profile of the soil in the study area was constructed from the frequency histogram,
on the assumption that each value represented an equal volume of soil. The depth of the
contaminated layer was set equal to the average number of readings above background in each
hole, corrected for estimated concentrations in the first 1.5 feet of soil and multiplied by 0.5 feet,
the vertical distance between successive exposure points. The calculated value was 8.75 feet, or
2.67 m, the value used in the analysis.
The NRC questioned the calibration procedure (NRC 92c): Wrenn etal. responded by presenting
additional calculations (Wr 92). Pending a direct calibration, relating the below-ground exposure
values determined from Nal detector readings to soil concentrations determined by laboratory
analyses of soil samples, the concentration data should be regarded as provisional. The
distribution of Th-232 at Reference Site XXI is shown in Figure 4-24.
Review Draft - 9/26/94 4-100 Do Not Cite Or Quote
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O
o
O
fit
O
D)
X
03
Figure 4-24
Reference Site XXI
Distribution of Contaminated Soil
10 15 20 25
Volume of Soil to be Removed (m**3)
Thousands
Th-232
30
35
Total Contaminated Volume = 2.89E+4 m**3
Additional Nuclides: Ra-228 and Th-228
-------
REFERENCE SITE XXII
Reference Site XXII is based in part on the Maywood Chemical Company site. It is essential
to bear in mind that the following analysis of this reference site, although it makes use of some
of the data that characterizes the Maywood site, cannot be considered to be an analysis of the
actual site. In particular, the predicted impacts refer only to the reference site and cannot be used
to predict future impacts of the much more complicated Maywood site.
Site Description
The Maywood site is located in northern New Jersey approximately 12 miles north-northwest of
New York City and 13 miles northeast of Newark, New Jersey. The Maywood Chemical Works
extracted thorium and rare earths from monazite ore from 1916 until 1959. More than 80 vicinity
properties became contaminated with radioactive materials as a result of waste disposal
operations, construction activities, and surface water movement. The Maywood Interim Storage
Site (MISS) is a 12-acre fenced lot containing a waste storage pile consisting of contaminated
materials from previous decontamination activities.
The Remedial Investigation (RI) identifies four operable units (OUs) based on land use. These
OUs include:
MISS
the Stepan Company property
• commercial/government properties
residential properties and municipal parks
Because of widely varying contaminant levels and estimated risks, the baseline risk assessment
further subdivided these OUs into 12 "property units".
Environmental Parameters
The soil of the vadose zone at the Maywood site is more than 50% sand and contains varying
amounts of silt and clay. It has a hydraulic conductivity of 68.4 m/yr (DOE 92f, p. 3-11), a total
porosity of 0.4 and an effective porosity of 0.22 (DOE 92f, p. 3-11). These values, along with
the representative exponential parameter (b) value for sandy soils tabulated in the RESRAD
references, were assigned to Reference Site XXII and are listed in Table 4-8. Representative
RESRAD Kd values in sandy soils were assigned to each nuclide at Reference Site XXII.
Review Draft - 9/26/94 4-102 Do Not Cite Or Quote
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The precipitation rate at Maywood is 1.07 m/yr (DOE 92f, p. 3-11). The water balance at the
Maywood site was calculated by DOE using the CREAMS (Chemicals, Runoff and Erosion from
Agricultural Management Systems) model developed by the Department of Agriculture. The
results of this calculation listed the evapotranspiration rate at 0.56 m/yr and the surface runoff at
0.31 m/yr. While no irrigation practices are currently being used at the Maywood site, an average
value of 0.2 m/yr for humid areas (ANL 93b, p. 68) is assumed for future use scenarios. Based
on these data an infiltration rate of 0.40 m/yr was calculated using the method described for the
RESRAD computer model (ANL 93b, p. 61), and assigned to Reference Site XXII.
The uppermost water-bearing unit consists of unconsolidated sediments and weathered
sedimentary rock (DOE 92f, pp. 3-45 and 3-53), with a mean hydraulic conductivity of 120 m/yr,
a total porosity of 0.2 (DOE 92f, pp. 3-53 and 3-64) and a gradient of 0.01 (DOE 92f, pp. 3-56
to 3-58). These values were assigned to Reference Site XXII, along with an assumed effective
porosity of 0.2 and a representative RESRAD value of the exponential parameter (b) in silty
loam. The depth to the water table ranges from 1.5 to 4.6 meters (DOE 92f, p. 3-45). The
arithmetic mean of approximately 3 meters was assigned to Reference Site XXII.
Soil Contamination
Data sources. An RI was completed for the Maywood site in 1992 (DOE 92f). Extensive
sampling and analysis activities were included in the RI investigation, and a baseline risk
assessment (BRA) was completed as part of the RI (DOE 93e).
The results of soil sample analyses for three radionuclides—U-238, Th-232, and Ra-226—are
presented in the BRA. The mean specific activities of each nuclide in both the surface soils and
subsoils of each of 10 of the 12 property units are listed in Table 4-20, below. The surface soil
samples were collected between the surface and a depth of two feet (0.6 m). The subsoil samples
were collected at depths of greater than two feet—no lower limit is cited (DOE 93e, p. 3-28).
The BRA lists background concentrations in the soil for the three principal nuclides at three
locations in the vicinity of the site. Each of the background values listed in Table 2-1 of the BRA
is preceded by a "<" symbol, implying that the levels were less than the lower detectable limit.
All the values for U-238 are abnormally high, with an average of "<2.9 pCi/g." (The values for
Th-232 and Ra-226 are within the normal range.) Nevertheless, the BRA subtracts each of these
values from the mean concentrations at the contaminated properties.
Review Draft - 9/26/94 4-103 Do Not Cite Or Quote
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While the actual areas of the individual property units were not provided, a map showing the
boundaries of the OUs as well as the property units was included in the BRA (DOE 93e, p. 1-5).
The areas of the contaminated soils were determined by measuring the areas of the respective
units on the map .
Modeling of contamination. The volume of contaminated surface soil in each subunit was
calculated by multiplying the area of the unit by the two-foot thickness of the soil layer. These
volumes are listed in Table 4-20, below. The subsoils extend from the bottom of the surface soil
layer to the bottom of the entire contaminated zone. The RESRAD analysis presented in the BRA
used a value of 2 m as the thickness of the contaminated zone (DOE 93e,p. E-l). This value was
used to calculate the volumes of subsoil at each unit, and was also assigned to the thickness of
the contaminated zone of Reference Site XXII.
To characterize the soil contamination at Reference Site XXII, it was assumed that the uranium
contamination exhibited the same relative isotopic abundance as natural uranium, i.e., the specific
activities of U-238, U-235 and U-234 were in the ratio of 1 :.047:1. It was further assumed that
Th-232 was in secular equilibrium with its two short-lived daughter products, Ra-228 and Th-
228, and that Pb-210 was in equilibrium with Ra-226.
The distribution for each nuclide at Reference Site XXII was constructed by sorting the volumes
into a number of bins, according to the mean specific activity of the given nuclide in each
volume. The distributions of the radioactive daughter products assumed to be in secular
equilibrium are identical to those of the parent. U-234 has the same distribution as U-238, while
the specific activities of U-235 are 4.7% those of U-238. The distributions of the principal
nuclides are shown in Figure 4-25. To enable the modeling of cleanup to low risk levels, the
distribution curves were extrapolated to low specific activities.
The Radionuclide concentrations reported in Table 4-20 are concentrations above background.
The background concentrations for these radionuclides were reported as being below the
detection limit, but the actual background concentrations were not reported. Variations in the
natural background may account for reported radionuclide concentrations in the range of 0.1 to
0.5 pCi/g above background. Values reported in this range have been used to determine the
radionuclide distribution at Reference Site XXII, but these values may have a high level of
uncertainty associated with them.
Review Draft - 9/26/94 4-104 Do Not Cite Or Quote
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The distributions for Reference Site XXII assume that the distributions of radionuclides within
the surface soil or subsoil of each unit are uniform. This is probably not the case. An alternate
interpretation of this model is that the projected cleanup would deal with the site in terms of
property units—the decision would be whether to clean up an entire unit or to leave the
contamination in place. Although neither assumption is entirely satisfactory, it is the only
plausible model that can be based on the presently available data.
Table 4-20. Radioactive Contamination at 10 Vicinity Properties on the Maywood Site
Site ID
1
2
3
3h
4
5
6
7
7h
8
Area
(m2)
32,000
7,000
43,000
31,000
32,000
140,000
47,000
154,000
28,000
8,000
Surface (0 to 0.6 m)
Volume
(m3)
19,200
4,200
25,800
18,600
19,200
84,000
28,200
92,400
16,800
4,800
Concentration (pCi/g)
Th-232
2.88
9.05
3.45
16.33
1.21
2.05
7.91
18.06
46.76
17.1
Ra-226
0.52
1.08
0.61
3.77
0.17
0.31
1.43
1.92
4.93
1.47
U-238
3.39
8.43
1.69
4.37
0.96
1.98
12.78
24.27
26.6
10.53
Subsurface (0.6 to 2 m)
Volume
(m3)
44,800
9,800
60,200
43,400
44,800
196,000
65,800
215,600
39,200
11,200
Concentration (pCi/g)
Th-232
1.57
5.53
3.46
33.29
2.11
0.68
16.42
16.5
10.16
37.62
Ra-226
0.30
0.74
0.74
7.06
0.11
0.19
2.69
4.29
2.11
1.97
U-238
2.32
5.15
1.74
5.03
0.84
1.18
16.14
31.47
33.43
10.58
Review Draft - 9/26/94
4-105
Do Not Cite Or Quote
-------
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£ 1E+1
= 1E+0
03
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— 1E-2
CO
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03
1E-3
1E-4
0
Figure 4-25
Reference Site XXII
Distribution of Contaminated Soil
0.5 1 1.5
Volume of Soil to be Removed (m**3)
Millions
Ra-226 Th-232 U-238
2.5
Total Contaminated Volume = 1.04E+6 m**3
Additional Nuclides: Ra-228, Th-228, U-234 & U-23£
-------
5. Analysis of Reference Sites
Each of the reference sites described in Section 4.4.3 was analyzed to determine the amount of
soil cleanup required to achieve one of nine alternative risk-based cleanup goals. (Additional
analyses for dose-based cleanup levels are presented in Appendix M.) Each of these goals seek
to limit radiation exposure and risk to an individual to a lifetime cancer incidence risk of IxlO"2,
IxlO'3, 7xlO'4, 5xlO'4, 3xlO'4, 2xlO'4, IxlO'4, IxlO'5 or IxlO'6, with reasonable maximum exposure
(RME) assumptions (discussed in Chapter 2). Specific objectives of the analysis were to
determine:
the volume of soil on each site that may require remediation,
the potential radiological health effects averted through remediation, and
the potential radiological health effects on workers at the site and on the near-by
public as a result of activities associated with remediation.
5.1 SOIL CLEANUP VOLUMES FOR REFERENCE SITES
A three-step process was used to estimate the volume of soil that must be remediated to achieve
a desired risk-based cleanup goal at each reference site:
Step 1: Characterize the distribution of each radionuclide in the soil of each
reference site. (This step is described in Section 4.4.4)
Step 2: Determine a site-specific risk factor for each radionuclide: the relationship
between the maximum concentration of a given radionuclide in the soil and the RME
individual's lifetime risk of cancer incidence, expressed as risk per pCi/g.1
Step 3: Using site-specific risk factors and radionuclide distributions, determine the
volume of soil that must be remediated (i.e., the cleanup volume) to achieve the
desired cleanup goal.2
Generic test site risk factors have also been calculated for purposes of comparison - see Tables 3-1 through
3-3.
2 Although it is convenient to visualize the mathematical relationships between volumes and radionuclide
concentrations as a series of curves, the analysis was performed mathematically, not graphically. The figures
that depict these relationships are for the purpose of illustration~they played no role in the analysis.
Review Draft - 9/26/94 5-1 Do Not Cite Or Quote
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5.1.1 Step 2: Derivation of Risk Factors
As discussed in Chapter 3, risk factors define the relationship between a given concentration of
a radionuclide in soil and the risk to individuals who may reside or work at the site. As such,
they are useful in determining not only the risks to individuals at a site, but also the volume of
soil that may require remediation at a site to meet specified risk-based cleanup goals for an
exposed individual, assuming RME conditions. Section 3.1 presents generic risk factors which
are broadly applicable to most sites. This section describes site-specific risk factors.
Site-specific risk factors for each radionuclide were derived using RESRAD Version 5.19 and the
site-specific environmental parameters described in Section 4.2.3 and Tables 4-5 through 4-8.
Two sets of risk factors were tabulated for each site: one set assumes rural residential occupancy
(including agriculture), which corresponds to the site's being released for unrestricted use, while
the other is for commercial/industrial occupancy which corresponds to the site's being restricted
to industrial or commercial use. Separate risk factors correspond to the RME individual's
occupying the site for some thirty-year period during the next 100, 1,000 or 10,000 years,
yielding six factors for each radionuclide. In the majority of cases studied, the maximum risk
occurs during the first 100 years; therefore, the risk factors do not increase if the study period
is extended.
Risk factors for nuclides which can produce significant amounts of Rn-222 as a result of
radioactive decay during the study periods (i.e.., U-234, Th-230 and Ra-226) two complete sets
of risk factors were calculated: one with and one without the radon pathway.
It is worth noting that, in general, site-specific rural residential site risk factors are lower than the
corresponding generic test site risk factors. This occurs because the generic site factors are based
on a number of conservative default assumptions. Some of the key default assumptions, and the
ways in which they affect the risk factors, are:
The generic test site residential risk factors are based on the assumption that all
plausible exposure pathways are present at the site, including an on-site farm, beef
and milk cows, and an on-site well. Not all these pathways are necessarily relevant
to a given site.
The thickness of the contaminated zone for the generic test site is 2 meters. This is
relatively thick as compared to most of the reference sites. Once the thickness of the
contaminated zone exceeds about 0.2 meters, however, the risk per pCi/g no longer
Review Draft - 9/26/94 5-2 Do Not Cite Or Quote
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increases significantly for most nuclides. Accordingly, this assumption places an
effective upper bound on the water-independent pathways, such as direct radiation.
The area of the contaminated zone for the generic test site is IxlO4 m2. This is not
very large compared to most reference sites. However, the risk per pCi/g does not
increase significantly for areas greater than IxlO4 m2. This assumption also tends
to place an upper bound on the water independent pathways, such as direct radiation.
The thickness of the uncontaminated unsaturated zone for the generic test site is 2
meters. This is a relatively shallow unsaturated zone, which results in an
overestimate of risks for the groundwater pathway for most sites.
Distribution coefficients (Kd) at the low end of the range of published values were
used for the generic test site. The Kd is an expression of the binding capability of
radionuclides to soil. The lower the Kd, the greater the potential for the contaminants
to enter the groundwater. As a result, the use of low-end Kd values tends to
overestimate the risks via the groundwater pathway.
The depth of the on-site well for the generic test site is 3 meters below the water
table. Most wells are screened below 3 meters. This assumption results in minimal
dilution of the contaminants in the saturated zone, thereby resulting in a conservative
estimate of risk from the groundwater pathways.
5.1.2 Step 3: Soil Cleanup Volumes
Once the soil contamination pattern at a site is defined (Step 1) and risk factors are developed
(Step 2), the soil cleanup volumes required to achieve a specified risk-based cleanup goal can be
determined.3 If only one nuclide is found at the site, the cleanup level—the maximum
concentration of the contaminant that remains anywhere on the site following cleanup—is
calculated by dividing the selected risk goal by the appropriate risk factor for that nuclide. The
volume of soil having radionuclide concentrations greater than the calculated value can then be
readily determined by solving the equation that relates the volume to the concentration. For
example, the site-specific risk factor for residential occupancy of Reference Site I was calculated
to be 2.66xlO"5 per pCi/g of Cs-137, the only nuclide at this site. To achieve the goal of 10"4 risk
3 The reader should bear in mind that the cleanup goal must be specified not only in terms of the level of risk
to the RME individual, but also in terms of the future period of concern (i.e., 100, 1,000 or 10,000 years)
and whether rural residential or commercial/industrial occupancy is anticipated.
Review Draft - 9/26/94 5-3 Do Not Cite Or Quote
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to the RME individual, the maximum concentration must be 10"4-^2.66xlO"5 = 3.76 pCi/g Cs-137.
The distribution curve shown in Figure 4-2 shows that approximately 5xl05 m3 of soil are
contaminated at or above this concentration—this is the volume of soil that would have to be
remediated to achieve the 10"4 cleanup goal. (The actual value, calculated analytically, is listed
in Table 5-1, below).
For sites with multiple radionuclides, the calculation procedure is more complicated, because the
sum of the risks from each nuclide must equal the cleanup goal. The volumes in such cases are
determined by an iterative procedure involving trial and error. The calculation may be visualized
by examining a graphical illustration of the result. Table 5-1 indicates that 614 m3 of soil must
be remediated at Reference Site XVIA to achieve a risk-based cleanup goal of 10"3, based on
residential occupancy during the first 1,000 years. Figure 4-21 in the previous chapter shows that
remediating this volume would leave maximum concentrations of ~5 pCi/g of Co-60 and ~1
pCi/g of Cs-137. The 1,000-year rural residential risk factors for the two nuclides at this site are
2.03xlO"4 and 4.83xlO"5, respectively. Multiplying the maximum concentration of each nuclide
by its risk factor and adding the products yields a risk of approximately 10"3. A more precise
verification of the risk can be performed by using the actual concentrations, which are listed on
page K-110 in Appendix K. As discussed in Note 2, the actual calculations are performed
analytically, not graphically.
Tables 5-1 through 5-4 present the derived soil cleanup volumes for each reference site, using
rural residential or commercial risk factors, with and without the radon pathway, for occupancy
during the first 100, 1,000 and 10,000 years.4 In many cases, the documents and other data on
the actual sites that formed the bases for the reference sites (the basis sites discussed in Chapter
4) did not include data on the low levels of contamination that correspond to risk levels as low
as IxlO"6. To perform the analyses corresponding to these and, in some cases, to higher risk
level, it was necessary to extrapolate the known data to lower concentrations and correspondingly
higher volumes. In the case of some reference sites, this was done a priori by creating
distributions that extend to concentrations lower than those that could be realistically detected
above the ambient soil background distribution. In the case of other sites, distributions
4 Although the radon pathway is only relevant to sites contaminated with U-234 or its progeny, the complete
set of reference sites is listed in each table for ease of reference.
Review Draft - 9/26/94 5-4 Do Not Cite Or Quote
-------
Table 5-1. Soil Volumes Requiring Remediation, Using Residential Risk Factors, Excluding Indoor Radon
Cleanup Volumes (m**3)-Indoor radon pathway excluded
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
5 . OOE+6
1.89E+6
8 .44E+5
2 . 55E+5
1.51E+7
5.56E+5
3 . 80E+7
1.65E+5
8 .33E+5
6 . 88E+3
2.49E+3
2.49E+3
2 .49E+3
1.27E+3
1.27E+3
1 .27E+3
5 . 92E+2
5.92E+2
5.92E+2
4 . 74E+5
4.74E+5
4.74E+5
3 .45E+4
3 .45E+4
3 .45E+4
2.48E+6
9.19E+7
2.81E+4
7 .59E+6
9.95E+7
1,000
5 . OOE+6
1.90E+6
8 .44E+5
2 . 55E+5
1.51E+7
5.56E+5
3 . 80E+7
1.65E+5
8 .33E+5
6 . 88E+3
2.49E+3
2.49E+3
2 .49E+3
1.27E+3
1.27E+3
1 .27E+3
5 . 92E+2
5.92E+2
5.92E+2
4 . 74E+5
4.74E+5
4.74E+5
3 .45E+4
3 .45E+4
3 .45E+4
2.48E+6
9.19E+7
2.81E+4
7 .59E+6
9.95E+7
10,000
5 . OOE+6
1.90E+6
8 .44E+5
2 . 55E+5
1.51E+7
5.56E+5
3 . 80E+7
1.65E+5
8.33E+5
6 . 88E+3
2.49E+3
2.49E+3
2 .49E+3
1.27E+3
1.27E+3
1 .27E+3
5 . 92E+2
5.92E+2
5.92E+2
4 . 74E+5
4.74E+5
4.74E+5
3 .45E+4
3 .45E+4
3 .45E+4
2.48E+6
9.19E+7
2.81E+4
7 .59E+6
9.95E+7
l.E-5
100
1 .53E+6
1.30E+6
7.99E+5
9. 73E+4
1. 05E+7
3 .96E+5
9.26E+6
2.96E+4
7.18E+5
1. 70E+3
6.89E+2
6.89E+2
6 . 89E+2
1. 11E+3
1. 11E+3
1. 11E+3
5 . 89E+2
5.89E+2
5.89E+2
5. 50E+4
5.50E+4
5.50E+4
3 .42E+4
3 .42E+4
3 .42E+4
1.83E+6
4 .59E+7
7.55E+3
1 . 70E+6
4 . 76E+7
1,000
1 .53E+6
1.31E+6
7.99E+5
9. 73E+4
1. 05E+7
3 .96E+5
9.26E+6
2.96E+4
7.82E+5
1. 70E+3
6.89E+2
6.89E+2
6 . 89E+2
1. 11E+3
1. 11E+3
1. 11E+3
5 . 89E+2
5.89E+2
5.89E+2
5. 50E+4
5.50E+4
5.50E+4
3 .42E+4
3 .42E+4
3 .42E+4
1.83E+6
4.60E+7
7.55E+3
1 . 70E+6
4 . 77E+7
10,000
1 .53E+6
1.31E+6
7.99E+5
9. 73E+4
1. 05E+7
3 .96E+5
9.26E+6
2.96E+4
7.82E+5
1. 70E+3
6.89E+2
6.89E+2
6 . 89E+2
1. 11E+3
1. 11E+3
1. 11E+3
5 . 89E+2
5.89E+2
5.89E+2
5. 50E+4
5.50E+4
5.50E+4
3 .42E+4
3 .42E+4
3 .42E+4
1.83E+6
4.60E+7
7.55E+3
1 . 70E+6
4 . 77E+7
l.E-4
100
4 . 66E+5
8 .95E+5
4.63E+5
3 . 71E+4
6.02E+6
2.36E+5
3 . 67E+6
1.98E+3
4.03E+5
1.41E+3
.OOE+0
.OOE+0
. OOE+0
9.41E+2
9.41E+2
9.41E+2
5. 80E+2
5.80E+2
5.80E+2
2 .26E+3
2.26E+3
2.26E+3
3 .18E+4
3 .18E+4
3 .18E+4
1.18E+6
2.55E+7
1.41E+3
8 . 85E+5
2.64E+7
1,000
4 . 66E+5
9.28E+5
4.63E+5
3 . 71E+4
6.02E+6
2.36E+5
3 . 67E+6
1.98E+3
5.88E+5
1.41E+3
.OOE+0
.OOE+0
. OOE+0
9.41E+2
9.41E+2
9.41E+2
5. 80E+2
5.80E+2
5.80E+2
2 .26E+3
2.26E+3
2.26E+3
3 .18E+4
3 .18E+4
3 .18E+4
1.19E+6
2.58E+7
1.41E+3
8 . 85E+5
2.67E+7
10,000
4 . 66E+5
9.28E+5
4.63E+5
3 . 71E+4
6.02E+6
2.36E+5
3 . 67E+6
1.98E+3
5.88E+5
1.41E+3
.OOE+0
.OOE+0
. OOE+0
9.41E+2
9.41E+2
9.41E+2
5. 80E+2
5.80E+2
5.80E+2
2 .26E+3
2.26E+3
2.26E+3
3 .18E+4
3 .18E+4
3 .18E+4
1.19E+6
2.58E+7
1.41E+3
8 . 85E+5
2.67E+7
l.E-3
100
9. 30E+4
7.73E+5
6.65E+4
1.42E+4
2.26E+6
1.06E+5
1. 96E+4
.OOE+0
1.49E+5
7. 01E+2
.OOE+0
.OOE+0
. OOE+0
6. 14E+2
6. 14E+2
6 . 14E+2
4 . 56E+2
4.56E+2
4.56E+2
3 . OOE+1
3.00E+1
3. OOE+1
2 . 02E+4
2 . 02E+4
2.02E+4
6.34E+5
1.02E+7
7.01E+2
5. 51E+5
1.07E+7
1,000
9. 30E+4
7.84E+5
6.65E+4
1.42E+4
2.26E+6
1.06E+5
1. 96E+4
.OOE+0
1.82E+5
7. 01E+2
.OOE+0
.OOE+0
. OOE+0
6. 14E+2
6. 14E+2
6 . 14E+2
4 . 56E+2
4.56E+2
4.56E+2
3 . OOE+1
3. OOE+1
3. OOE+1
2 . 02E+4
2 . 02E+4
2.02E+4
6.63E+5
1.04E+7
7.01E+2
5. 51E+5
1. 10E+7
10,000
9. 30E+4
7.84E+5
6.65E+4
1.42E+4
2.26E+6
1.06E+5
1. 96E+4
.OOE+0
1.82E+5
7. 01E+2
.OOE+0
.OOE+0
. OOE+0
6. 14E+2
6. 14E+2
6 . 14E+2
4 . 56E+2
4.56E+2
4.56E+2
3 . OOE+1
3. OOE+1
3. OOE+1
2 . 02E+4
2 . 02E+4
2.02E+4
6.63E+5
1.04E+7
7.01E+2
5. 51E+5
1. 10E+7
l.E-2
100
8 . 82E+3
6.06E+5
.OOE+0
. OOE+0
3.93E+5
2.96E+4
. OOE+0
.OOE+0
3.31E+4
4 . 94E+2
.OOE+0
.OOE+0
. OOE+0
2.50E+2
2.50E+2
2 . 50E+2
1. 69E+2
1.69E+2
1.69E+2
. OOE+0
.OOE+0
.OOE+0
4 . 60E+3
4 . 60E+3
4.60E+3
1.02E+5
2.42E+6
4.94E+2
1.43E+5
2.56E+6
1,000
8 . 82E+3
6. 17E+5
.OOE+0
. OOE+0
3.93E+5
2.96E+4
. OOE+0
.OOE+0
3.62E+4
4 . 94E+2
.OOE+0
.OOE+0
. OOE+0
2.50E+2
2.50E+2
2 . 50E+2
1. 69E+2
1.69E+2
1.69E+2
. OOE+0
.OOE+0
.OOE+0
4 . 60E+3
4 . 60E+3
4.60E+3
1.73E+5
2.93E+6
4.94E+2
1.43E+5
3.07E+6
10,000
8 . 82E+3
6. 17E+5
.OOE+0
. OOE+0
3.93E+5
2.96E+4
. OOE+0
.OOE+0
3.62E+4
4 . 94E+2
.OOE+0
.OOE+0
. OOE+0
2.50E+2
2.50E+2
2 . 50E+2
1. 69E+2
1.69E+2
1.69E+2
. OOE+0
.OOE+0
.OOE+0
4 . 60E+3
4 . 60E+3
4.60E+3
1.73E+5
2.93E+6
4.94E+2
1.43E+5
3.07E+6
-------
Table 5-2. Soil Volumes Requiring Remediation, Using Commercial Risk Factors, Excluding Indoor Radon
Cleanup Volumes (m**3)-Indoor radon pathway excluded
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XI I IB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
2 . 66E+6
1.53E+6
8 .32E+5
1.48E+5
1.27E+7
4 . 71E+5
1. 62E+7
6.21E+4
7.85E+5
2 . 17E+3
1.41E+3
1.41E+3
1.41E+3
1. 19E+3
1. 19E+3
1. 19E+3
5.92E+2
5.92E+2
5 . 92E+2
1. 11E+5
1. 11E+5
1. 11E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .12E+6
6 . 02E+7
1.41E+4
2.50E+6
6 .27E+7
1,000
2 . 66E+6
1.54E+6
8 .32E+5
1.48E+5
1.27E+7
4 . 71E+5
1. 62E+7
6.21E+4
8 . OOE+5
2 . 17E+3
1.41E+3
1.41E+3
1.41E+3
1. 19E+3
1. 19E+3
1. 19E+3
5.92E+2
5.92E+2
5 . 92E+2
1. 11E+5
1. 11E+5
1. 11E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .12E+6
6 . 02E+7
1.41E+4
2.50E+6
6 .28E+7
10,000
2 . 66E+6
1.54E+6
8 .32E+5
1.48E+5
1.27E+7
4 . 71E+5
1. 62E+7
6.21E+4
8 . OOE+5
2 . 17E+3
1.41E+3
1.41E+3
1.41E+3
1. 19E+3
1. 19E+3
1. 19E+3
5.92E+2
5.92E+2
5 . 92E+2
1. 11E+5
1. 11E+5
1. 11E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .12E+6
6 . 02E+7
1.41E+4
2.50E+6
6 .28E+7
l.E-5
100
8 . 12E+5
9.56E+5
6.91E+5
5. 65E+4
8. 13E+6
3. 11E+5
6 . 66E+6
7.06E+3
5.65E+5
1. 55E+3
1.92E+2
1.92E+2
1. 92E+2
1.03E+3
1. 03E+3
1. 03E+3
5.84E+2
5.84E+2
5. 84E+2
1. 12E+4
1. 12E+4
1. 12E+4
3 .36E+4
3 .36E+4
3 .36E+4
1 .47E+6
3 .51E+7
3 . 18E+3
1. 06E+6
3 . 62E+7
1,000
8 . 12E+5
9.60E+5
6.91E+5
5. 65E+4
8. 13E+6
3. 11E+5
6 . 66E+6
7.06E+3
7.47E+5
1. 55E+3
1.92E+2
1.92E+2
1. 92E+2
1.03E+3
1. 03E+3
1. 03E+3
5.84E+2
5.84E+2
5. 84E+2
1. 12E+4
1. 12E+4
1. 12E+4
3 .36E+4
3 .36E+4
3 .36E+4
1 .47E+6
3 .53E+7
3 . 18E+3
1. 06E+6
3 . 64E+7
10,000
8 . 12E+5
9.60E+5
6.91E+5
5. 65E+4
8. 13E+6
3. 11E+5
6 . 66E+6
7.06E+3
7.47E+5
1. 55E+3
1.92E+2
1.92E+2
1. 92E+2
1.03E+3
1. 03E+3
1. 03E+3
5.84E+2
5.84E+2
5. 84E+2
1. 12E+4
1. 12E+4
1. 12E+4
3 .36E+4
3 .36E+4
3 .36E+4
1 .47E+6
3 .53E+7
3 . 18E+3
1. 06E+6
3 . 64E+7
l.E-4
100
2 . 06E+5
7.97E+5
1.62E+5
2 . 38E+4
3.77E+6
1.54E+5
5.41E+5
1.45E+2
2.61E+5
8 . 06E+2
.OOE+0
.OOE+0
. OOE+0
7.95E+2
7. 95E+2
7. 95E+2
5.30E+2
5.30E+2
5. 30E+2
5.84E+1
5.84E+1
5. 84E+1
2.57E+4
2.57E+4
2 . 57E+4
8 .43E+5
1.51E+7
8 . 06E+2
6.98E+5
1. 58E+7
1,000
2 . 06E+5
8.32E+5
1.62E+5
2 . 38E+4
3.77E+6
1.54E+5
5.41E+5
1.45E+2
4.07E+5
8 . 06E+2
.OOE+0
.OOE+0
. OOE+0
7.95E+2
7. 95E+2
7. 95E+2
5.30E+2
5.30E+2
5. 30E+2
5.84E+1
5.84E+1
5. 84E+1
2.57E+4
2.57E+4
2 . 57E+4
9. 07E+5
1.57E+7
8 . 06E+2
6.98E+5
1. 64E+7
10,000
2 . 06E+5
8.32E+5
1.62E+5
2 . 38E+4
3.77E+6
1.54E+5
5.41E+5
1.45E+2
4.07E+5
8 . 06E+2
.OOE+0
.OOE+0
. OOE+0
7.95E+2
7. 95E+2
7. 95E+2
5.30E+2
5.30E+2
5. 30E+2
5.84E+1
5.84E+1
5. 84E+1
2.57E+4
2.57E+4
2 . 57E+4
9. 07E+5
1.57E+7
8 . 06E+2
6.98E+5
1. 64E+7
l.E-3
100
3 . 59E+4
7. 15E+5
5.53E+3
1. 72E+3
7.88E+5
5.41E+4
. OOE+0
.OOE+0
8.97E+4
5. 73E+2
.OOE+0
.OOE+0
. OOE+0
4.56E+2
4 . 56E+2
4 . 56E+2
2.97E+2
2.97E+2
2 . 97E+2
6.51E+0
6.51E+0
6 . 51E+0
1.04E+4
1.04E+4
1. 04E+4
4 . 90E+5
6.25E+6
5. 73E+2
3.05E+5
6 . 56E+6
1,000
3 . 59E+4
7.24E+5
5.53E+3
1. 72E+3
7.88E+5
5.41E+4
. OOE+0
.OOE+0
1.02E+5
5. 73E+2
.OOE+0
.OOE+0
. OOE+0
4.56E+2
4 . 56E+2
4 . 56E+2
2.97E+2
2.97E+2
2 . 97E+2
6.51E+0
6.51E+0
6 . 51E+0
1.04E+4
1.04E+4
1. 04E+4
4 . 99E+5
6.34E+6
5. 73E+2
3.05E+5
6 . 64E+6
10,000
3 . 59E+4
7.24E+5
5.53E+3
1. 72E+3
7.88E+5
5.41E+4
. OOE+0
.OOE+0
1.02E+5
5. 73E+2
.OOE+0
.OOE+0
. OOE+0
4.56E+2
4 . 56E+2
4 . 56E+2
2.97E+2
2.97E+2
2 . 97E+2
6.51E+0
6.51E+0
6 . 51E+0
1.04E+4
1.04E+4
1. 04E+4
4 . 99E+5
6.34E+6
5. 73E+2
3.05E+5
6 . 64E+6
l.E-2
100
1. 70E+3
2.76E+5
.OOE+0
. OOE+0
2.99E+4
1.08E+4
. OOE+0
.OOE+0
1.33E+4
8 .26E+1
.OOE+0
.OOE+0
. OOE+0
8.87E+1
8 . 87E+1
8 . 87E+1
5.97E+1
5.97E+1
5. 97E+1
.OOE+0
.OOE+0
. OOE+0
1. 10E+3
1. 10E+3
1. 10E+3
. OOE+0
5.69E+5
8 .26E+1
3.90E+4
6 . 08E+5
1,000
1. 70E+3
2.92E+5
.OOE+0
. OOE+0
2.99E+4
1.08E+4
. OOE+0
.OOE+0
1.41E+4
8 .26E+1
.OOE+0
.OOE+0
. OOE+0
8.87E+1
8 . 87E+1
8 . 87E+1
5.97E+1
5.97E+1
5. 97E+1
.OOE+0
.OOE+0
. OOE+0
1. 10E+3
1. 10E+3
1. 10E+3
. OOE+0
5.86E+5
8 .26E+1
3.90E+4
6 .25E+5
10,000
1. 70E+3
2.92E+5
.OOE+0
. OOE+0
2.99E+4
1.08E+4
. OOE+0
.OOE+0
1.41E+4
8 .26E+1
.OOE+0
.OOE+0
. OOE+0
8.87E+1
8 . 87E+1
8 . 87E+1
5.97E+1
5.97E+1
5. 97E+1
.OOE+0
.OOE+0
. OOE+0
1. 10E+3
1. 10E+3
1. 10E+3
. OOE+0
5.86E+5
8 .26E+1
3.90E+4
6 .25E+5
-------
Table 5-3. Soil Volumes Requiring Remediation, Using Residential Risk Factors, Including Indoor Radon
Cleanup Volumes (m**3)-Indoor radon pathway included
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XI I IB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
5 . OOE+6
1.89E+6
8 .44E+5
2 . 55E+5
1.51E+7
5.56E+5
3 . 80E+7
1.65E+5
8 .33E+5
6 . 88E+3
2.49E+3
2.49E+3
2 .49E+3
1.27E+3
1.27E+3
1 .27E+3
5 . 92E+2
5.92E+2
5.92E+2
4 . 74E+5
4.74E+5
4.74E+5
3 .45E+4
3 .45E+4
3 .45E+4
2.61E+6
9.28E+7
2.81E+4
7 .59E+6
1. OOE+8
1,000
5 . OOE+6
1.91E+6
8 .44E+5
2 . 55E+5
1.51E+7
5.56E+5
3 . 80E+7
1.65E+5
8 .33E+5
6 . 88E+3
2.49E+3
2.49E+3
2 .49E+3
1.27E+3
1.27E+3
1 .27E+3
5 . 92E+2
5.92E+2
5.92E+2
4 . 94E+5
4.74E+5
4.74E+5
3 .45E+4
3 .45E+4
3 .45E+4
2.61E+6
9.28E+7
2.81E+4
7 . 68E+6
1. OOE+8
10,000
5 . OOE+6
1.91E+6
8 .44E+5
2 . 55E+5
1.51E+7
5.56E+5
3 . 80E+7
1.65E+5
8.33E+5
6 . 88E+3
2.49E+3
2.49E+3
2 .49E+3
1.27E+3
1.27E+3
1 .27E+3
5 . 92E+2
5.92E+2
5.92E+2
4 . 94E+5
4.74E+5
4.74E+5
3 .45E+4
3 .45E+4
3 .45E+4
2.61E+6
9.28E+7
2.81E+4
7 . 68E+6
1. OOE+8
l.E-5
100
1 .53E+6
1.35E+6
7.99E+5
9. 73E+4
1. 05E+7
3 .96E+5
9.26E+6
2.96E+4
7.18E+5
1. 70E+3
6.89E+2
6.89E+2
6 . 89E+2
1. 11E+3
1. 11E+3
1. 11E+3
5 . 89E+2
5.89E+2
5.89E+2
5. 50E+4
5.50E+4
5.50E+4
3 .42E+4
3 .42E+4
3 .42E+4
1.96E+6
4 .69E+7
7.55E+3
1 . 70E+6
4 .86E+7
1,000
1 .53E+6
1.36E+6
7.99E+5
9. 73E+4
1. 05E+7
3 .96E+5
9.26E+6
2.96E+4
7.82E+5
1. 70E+3
6.89E+2
6.89E+2
6 . 89E+2
1. 11E+3
1. 11E+3
1. 11E+3
5 . 89E+2
5.89E+2
5.89E+2
7. 97E+4
5.50E+4
5.50E+4
3 .42E+4
3 .42E+4
3 .42E+4
1.96E+6
4 . 70E+7
7.55E+3
1 . 81E+6
4 .88E+7
10,000
1 .53E+6
1.36E+6
7.99E+5
9. 73E+4
1. 05E+7
3 .96E+5
9.26E+6
2.96E+4
7.82E+5
1. 70E+3
6.89E+2
6.89E+2
6 . 89E+2
1. 11E+3
1. 11E+3
1. 11E+3
5 . 89E+2
5.89E+2
5.89E+2
7. 97E+4
5.50E+4
5.50E+4
3 .42E+4
3 .42E+4
3 .42E+4
1.96E+6
4 . 70E+7
7.55E+3
1 . 81E+6
4 .88E+7
l.E-4
100
4 . 66E+5
9 . 1 7E+5
4.63E+5
3 . 71E+4
6.02E+6
2.36E+5
3 . 67E+6
1.98E+3
4.03E+5
1.41E+3
.OOE+0
.OOE+0
. OOE+0
9.41E+2
9.41E+2
9.41E+2
5. 80E+2
5.80E+2
5.80E+2
2 .26E+3
2.26E+3
2.26E+3
3 .18E+4
3 .18E+4
3 .18E+4
1.31E+6
2.64E+7
1.41E+3
8 . 85E+5
2. 73E+7
1,000
4 . 66E+5
9.36E+5
4.63E+5
3 . 71E+4
6.02E+6
2.36E+5
3 . 67E+6
1.98E+3
5.88E+5
1.41E+3
.OOE+0
.OOE+0
. OOE+0
9.41E+2
9.41E+2
9.41E+2
5. 80E+2
5.80E+2
5.80E+2
5. 68E+3
2.26E+3
2.26E+3
3 .18E+4
3 .18E+4
3 .18E+4
1.31E+6
2.66E+7
1.41E+3
9 . 01E+5
2. 75E+7
10,000
4 . 66E+5
9.36E+5
4.63E+5
3 . 71E+4
6.02E+6
2.36E+5
3 . 67E+6
1.98E+3
5.88E+5
1.41E+3
.OOE+0
.OOE+0
. OOE+0
9.41E+2
9.41E+2
9.41E+2
5. 80E+2
5.80E+2
5.80E+2
5. 68E+3
2.26E+3
2.26E+3
3 .18E+4
3 .18E+4
3 .18E+4
1.31E+6
2.66E+7
1.41E+3
9 . 01E+5
2. 75E+7
l.E-3
100
9. 30E+4
7.81E+5
6.65E+4
1.42E+4
2.26E+6
1.06E+5
1. 96E+4
.OOE+0
1.49E+5
7. 01E+2
.OOE+0
.OOE+0
. OOE+0
6. 14E+2
6. 14E+2
6 . 14E+2
4 . 56E+2
4.56E+2
4.56E+2
3 . OOE+1
3.00E+1
3. OOE+1
2 . 02E+4
2 . 02E+4
2.02E+4
7.42E+5
1.09E+7
7.01E+2
5. 51E+5
1. 15E+7
1,000
9. 30E+4
7.90E+5
6.65E+4
1.42E+4
2.26E+6
1.06E+5
1. 96E+4
.OOE+0
1.82E+5
7. 01E+2
.OOE+0
.OOE+0
. OOE+0
6. 14E+2
6. 14E+2
6 . 14E+2
4 . 56E+2
4.56E+2
4.56E+2
4 .26E+1
3. OOE+1
3. OOE+1
2 . 02E+4
2 . 02E+4
2.02E+4
7.62E+5
1. 11E+7
7.01E+2
5. 51E+5
1. 17E+7
10,000
9. 30E+4
7.90E+5
6.65E+4
1.42E+4
2.26E+6
1.06E+5
1. 96E+4
.OOE+0
1.82E+5
7. 01E+2
.OOE+0
.OOE+0
. OOE+0
6. 14E+2
6. 14E+2
6 . 14E+2
4 . 56E+2
4.56E+2
4.56E+2
4 .26E+1
3. OOE+1
3. OOE+1
2 . 02E+4
2 . 02E+4
2.02E+4
7.62E+5
1. 11E+7
7.01E+2
5. 51E+5
1. 17E+7
l.E-2
100
8 . 82E+3
6.64E+5
.OOE+0
. OOE+0
3.93E+5
2.96E+4
. OOE+0
.OOE+0
3.31E+4
4 . 94E+2
.OOE+0
.OOE+0
. OOE+0
2.50E+2
2.50E+2
2 . 50E+2
1. 69E+2
1.69E+2
1.69E+2
. OOE+0
.OOE+0
.OOE+0
4 . 60E+3
4 . 60E+3
4.60E+3
3.05E+5
3.87E+6
4.94E+2
1.43E+5
4.02E+6
1,000
8 . 82E+3
6.71E+5
.OOE+0
. OOE+0
3.93E+5
2.96E+4
. OOE+0
.OOE+0
3.62E+4
4 . 94E+2
.OOE+0
.OOE+0
. OOE+0
2.50E+2
2.50E+2
2 . 50E+2
1. 69E+2
1.69E+2
1.69E+2
2 . 61E+0
.OOE+0
.OOE+0
4 . 60E+3
4 . 60E+3
4.60E+3
3.35E+5
4. 10E+6
4.94E+2
1.43E+5
4.24E+6
10,000
8 . 82E+3
6.71E+5
.OOE+0
. OOE+0
3.93E+5
2.96E+4
. OOE+0
.OOE+0
3.62E+4
4 . 94E+2
.OOE+0
.OOE+0
. OOE+0
2.50E+2
2.50E+2
2 . 50E+2
1. 69E+2
1.69E+2
1.69E+2
2 . 61E+0
.OOE+0
.OOE+0
4 . 60E+3
4 . 60E+3
4.60E+3
3.35E+5
4. 10E+6
4.94E+2
1.43E+5
4.24E+6
-------
Table 5-4. Soil Volumes Requiring Remediation, Using Commercial Risk Factors, Including Radon Pathway
Cleanup Volumes (m**3)-Indoor radon pathway included
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XI I IB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
2. 66E+6
1.55E+6
8 .32E+5
1.48E+5
1.27E+7
4 . 71E+5
1. 62E+7
6.21E+4
7.85E+5
2 . 17E+3
1.41E+3
1.41E+3
1.41E+3
1. 19E+3
1. 19E+3
1. 19E+3
5.92E+2
5.92E+2
5 . 92E+2
1. 11E+5
1. 11E+5
1. 11E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .26E+6
6 .12E+7
1.41E+4
2.50E+6
6 .37E+7
1,000
2 . 66E+6
1.55E+6
8 .32E+5
1.48E+5
1.27E+7
4 . 71E+5
1. 62E+7
6.21E+4
8 . OOE+5
2 . 17E+3
1.41E+3
1.41E+3
1.41E+3
1. 19E+3
1. 19E+3
1. 19E+3
5.92E+2
5.92E+2
5 . 92E+2
1.87E+5
1.58E+5
1. 11E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .26E+6
6 .12E+7
1.41E+4
3. 08E+6
6 .43E+7
10,000
2. 66E+6
1.55E+6
8 .32E+5
1.48E+5
1.27E+7
4 . 71E+5
1. 62E+7
6.21E+4
8 . OOE+5
2 . 17E+3
1.41E+3
1.41E+3
1.41E+3
1. 19E+3
1. 19E+3
1. 19E+3
5.92E+2
5.92E+2
5 . 92E+2
1.87E+5
1.58E+5
1. 11E+5
3 .44E+4
3 .44E+4
3 .44E+4
2 .26E+6
6 .12E+7
1.41E+4
3. 08E+6
6 .43E+7
l.E-5
100
8 . 12E+5
9.91E+5
6.91E+5
5. 65E+4
8. 13E+6
3. 11E+5
6 . 66E+6
7.06E+3
5.65E+5
1. 55E+3
1.92E+2
1.92E+2
1. 92E+2
1.03E+3
1. 03E+3
1. 03E+3
5.84E+2
5.84E+2
5. 84E+2
1. 12E+4
1. 12E+4
1. 12E+4
3 .36E+4
3 .36E+4
3 .36E+4
1 . 61E+6
3 .61E+7
3 . 18E+3
1. 06E+6
3 . 72E+7
1,000
8 . 12E+5
9.99E+5
6.91E+5
5. 65E+4
8. 13E+6
3. 11E+5
6 . 66E+6
7.06E+3
7.47E+5
1. 55E+3
1.92E+2
1.92E+2
1. 92E+2
1.03E+3
1. 03E+3
1. 03E+3
5.84E+2
5.84E+2
5. 84E+2
2. 17E+4
1.76E+4
1. 12E+4
3 .36E+4
3 .36E+4
3 .36E+4
1 . 61E+6
3 .63E+7
3 . 18E+3
1.14E+6
3 . 75E+7
10,000
8 . 12E+5
9.99E+5
6.91E+5
5. 65E+4
8. 13E+6
3. 11E+5
6 . 66E+6
7.06E+3
7.47E+5
1. 55E+3
1.92E+2
1.92E+2
1. 92E+2
1.03E+3
1. 03E+3
1. 03E+3
5.84E+2
5.84E+2
5. 84E+2
2. 17E+4
1.76E+4
1. 12E+4
3 .36E+4
3 .36E+4
3 .36E+4
1 . 61E+6
3 .63E+7
3 . 18E+3
1.14E+6
3 . 75E+7
l.E-4
100
2 . 06E+5
8.01E+5
1.62E+5
2 . 38E+4
3.77E+6
1.54E+5
5.41E+5
1.45E+2
2.61E+5
8 . 06E+2
.OOE+0
.OOE+0
. OOE+0
7.95E+2
7. 95E+2
7. 95E+2
5.30E+2
5.30E+2
5. 30E+2
5.84E+1
5.84E+1
5. 84E+1
2.57E+4
2.57E+4
2 . 57E+4
9. 71E+5
1.60E+7
8 . 06E+2
6.98E+5
1. 67E+7
1,000
2 . 06E+5
8.58E+5
1.62E+5
2 . 38E+4
3.77E+6
1.54E+5
5.41E+5
1.45E+2
4.07E+5
8 . 06E+2
.OOE+0
.OOE+0
. OOE+0
7.95E+2
7. 95E+2
7. 95E+2
5.30E+2
5.30E+2
5. 30E+2
9.53E+1
8. 12E+1
5. 84E+1
2.57E+4
2.57E+4
2 . 57E+4
1 . 01E+6
1.65E+7
8 . 06E+2
6.98E+5
1 . 72E+7
10,000
2 . 06E+5
8.58E+5
1.62E+5
2 . 38E+4
3.77E+6
1.54E+5
5.41E+5
1.45E+2
4.07E+5
8 . 06E+2
.OOE+0
.OOE+0
. OOE+0
7.95E+2
7. 95E+2
7. 95E+2
5.30E+2
5.30E+2
5. 30E+2
9.53E+1
8. 12E+1
5. 84E+1
2.57E+4
2.57E+4
2 . 57E+4
1 . 01E+6
1.65E+7
8 . 06E+2
6.98E+5
1 . 72E+7
l.E-3
100
3 . 59E+4
7.37E+5
5.53E+3
1. 72E+3
7.88E+5
5.41E+4
. OOE+0
.OOE+0
8.97E+4
5. 73E+2
.OOE+0
.OOE+0
. OOE+0
4.56E+2
4 . 56E+2
4 . 56E+2
2.97E+2
2.97E+2
2 . 97E+2
6.51E+0
6.51E+0
6 . 51E+0
1.04E+4
1.04E+4
1. 04E+4
5. 16E+5
6.45E+6
5. 73E+2
3.05E+5
6 . 76E+6
1,000
3 . 59E+4
7.46E+5
5.53E+3
1. 72E+3
7.88E+5
5.41E+4
. OOE+0
.OOE+0
1.02E+5
5. 73E+2
.OOE+0
.OOE+0
. OOE+0
4.56E+2
4 . 56E+2
4 . 56E+2
2.97E+2
2.97E+2
2 . 97E+2
1.31E+1
1. 10E+1
6 . 51E+0
1.04E+4
1.04E+4
1. 04E+4
5.24E+5
6.53E+6
5. 73E+2
3.05E+5
6 . 84E+6
10,000
3 . 59E+4
7.46E+5
5.53E+3
1. 72E+3
7.88E+5
5.41E+4
. OOE+0
.OOE+0
1.02E+5
5. 73E+2
.OOE+0
.OOE+0
. OOE+0
4.56E+2
4 . 56E+2
4 . 56E+2
2.97E+2
2.97E+2
2 . 97E+2
1.31E+1
1. 10E+1
6 . 51E+0
1.04E+4
1.04E+4
1. 04E+4
5.24E+5
6.53E+6
5. 73E+2
3.05E+5
6 . 84E+6
l.E-2
100
1. 70E+3
4. 14E+5
.OOE+0
. OOE+0
2.99E+4
1.08E+4
. OOE+0
.OOE+0
1.33E+4
8 .26E+1
.OOE+0
.OOE+0
. OOE+0
8.87E+1
8 . 87E+1
8 . 87E+1
5.97E+1
5.97E+1
5. 97E+1
.OOE+0
.OOE+0
. OOE+0
1. 10E+3
1. 10E+3
1. 10E+3
. OOE+0
7.07E+5
8 .26E+1
3.90E+4
7.46E+5
1,000
1. 70E+3
4.27E+5
.OOE+0
. OOE+0
2.99E+4
1.08E+4
. OOE+0
.OOE+0
1.41E+4
8 .26E+1
.OOE+0
.OOE+0
. OOE+0
8.87E+1
8 . 87E+1
8 . 87E+1
5.97E+1
5.97E+1
5. 97E+1
.OOE+0
.OOE+0
. OOE+0
1. 10E+3
1. 10E+3
1. 10E+3
. OOE+0
7.20E+5
8 .26E+1
3.90E+4
7. 59E+5
10,000
1. 70E+3
4.27E+5
.OOE+0
. OOE+0
2.99E+4
1.08E+4
. OOE+0
.OOE+0
1.41E+4
8 .26E+1
.OOE+0
.OOE+0
. OOE+0
8.87E+1
8 . 87E+1
8 . 87E+1
5.97E+1
5.97E+1
5. 97E+1
.OOE+0
.OOE+0
. OOE+0
1. 10E+3
1. 10E+3
1. 10E+3
. OOE+0
7.20E+5
8 .26E+1
3.90E+4
7. 59E+5
-------
that were based on actual site data were extrapolated past the last data points (corresponding
to the lowest reported concentrations) on the appropriate soil distribution curve shown in
Chapter 4.
As discussed in Chapter 4, the extrapolated data may be unrealistic because the pattern of
contamination of one more nuclides at a given site is unknown at concentrations that are
lower than the range of measured values. In addition, the data may project a cleanup level
that is well below the natural or man-made background for a given nuclide or below the
minimum detectable concentration (MDC), making the attainment of such levels technically
unfeasible. For example, cleaning up the soil at Reference Site I to achieve a IxlO"6 risk to
the RME individual, assuming rural residential occupancy, would require a Cs-137 level of
0.04 pCi/g above the local background level of Cs-137. Since a typical background level of
Cs-137 due to global fallout is 0.5 pCi/g at the Hanford site, this small increment over
background would be all but impossible to determine. A risk level of IxlO"5 requires cleaning
up to 0.38 pCi/g. Such a level is theoretically achievable, but there are no available data on
Cs-137 soil concentrations below -0.7 pCi/g (above average background) on this site.
In the present analysis, contamination is considered to be undetectable if the total
concentration, including background, is less than the upper limit of the background, or less
than the minimum detectable concentration (MDC), whichever is lower. Cleanup of soil that
does not contain at least one nuclide above a detectable level is indicated in the tables in this
chapter and in Appendix K by listing the corresponding soil volume or other derived quantity
in italics.
5.2 RADIOLOGICAL IMPACTS AVERTED DUE TO SOIL CLEANUP
One of the benefits associated with site cleanup is the reduction in the cumulative exposure
and associated health risks to the population residing on, or in the vicinity of, the
contaminated property following cleanup. In order to estimate the radiological health effects
averted by achieving a given cleanup level at each of the reference sites, it was necessary to
make certain assumptions about the future population density on each site, as well as whether
or not the site would be cultivated. In order to bracket a wide range of future uses of the
land, six different scenarios were constructed. These are described below.
Review Draft - 9/26/94 5-9 Do Not Cite Or Quote
-------
High Density Scenario. Population density is equal to 1,000 people per km2. Since such a
high density is incompatible with agriculture, no crops are raised on site.
Medium Density Scenarios. Two scenarios assume population densities of 100 people per
km2: one assumes no agriculture, the other assumes that the site is intensely cultivated.
Low Density Scenarios. Two scenarios assume population densities of 10 people per km2:
one with and one without agriculture.
Reasonable Occupancy Scenario. A "reasonable" population density was assigned to each
reference site, based on demographic data on the areas surrounding the corresponding basis
sites. The demographic data and the methods used to assign site-specific densities are
presented in Appendix D; the densities assigned to each of the reference sites are listed in
Table 4-3. Sites with densities of 300 people per km2 or less are assumed to be intensely
cultivated; no crops are raised on sites with higher densities.
For each reference site, it was assumed that the groundwater would be used extensively for
domestic purposes by people both on and off the site, and that all crops raised would be
consumed either on or off site. The specific population exposure pathways addressed include:
Direct radiation from living on contaminated soil
Inhalation of suspended dust
Exposure to indoor radon progeny (if applicable)
Ingestion of crops grown on contaminated soil (if applicable)
Ingestion of contaminated groundwater
Sites contaminated by U-234, Th-230 or Ra-226—nuclides which include Rn-222 in their
progeny—underwent two separate analyses. In one analysis, the calculation of risks to the
RME individual included risks posed by the inhalation of indoor radon; the modeling of
health effects averted by future populations likewise included the radon pathway. In the
second analysis, the individual risk calculation ignored the radon pathway—it was also
ignored in the assessment of population impacts averted. Thus, for sites at which radon is a
potential hazard, 12 distinct scenarios were modeled.
Review Draft - 9/26/94 5-10 Do Not Cite Or Quote
-------
Cumulative population exposures and the adverse health effects attributable to these exposures
were derived for each exposure pathway and for integration periods of 100, 1,000, and 10,000
years. These alternative pathways and time periods were explicitly addressed to support EPA
consideration of future land-use scenarios and time periods of interest for the rulemaking. A
simple computer model was developed to facilitate the performance of the calculations. A
summary of the methodology is provided in Section 2.2 of this report.
The calculation of radiological impacts averted consists of two distinct steps: (1) derivation
of population health effect factors; and (2) calculation of radionuclide inventories of
remediated soil
5.2.1 Step 1: Derivation of Population Health Effect Factors
The cumulative integrated population dose, expressed in person-rem, was calculated separately
for each nuclide at a given reference site, assuming a total activity of one curie distributed
uniformly throughout the contaminated soil. (The area and thickness of the contaminated
layer used both in these calculations and in the RESRAD risk assessments are listed in Table
4-6.) Separate calculations were performed for the three integration periods, for each of the
12 possible scenarios. Corresponding calculations were performed to determine the total
incidence of radiogenic cancers resulting from this unit activity, as well as the cancer fatalities
for the same set of circumstances. These calculations yielded a set of population health effect
factors—health effects per unit activity—for each nuclide at each site.
5.2.2 Step 2: Calculation of Radionuclide Inventories of Remediated Soil
The present analysis assumes that the cumulative population impacts are directly proportional
to the total inventory of each radionuclide at the site. The impacts averted are therefore
proportional to the activities removed, i.e., the inventories in the remediated soil. These
impacts can thus be determined by multiplying the total activity of each nuclide (expressed in
curies) in the volume of remediated soil by the health effect factor for that nuclide and adding
the products. Tables 5-5 through 5-8 list the fatal cancers averted by remediating the volumes
of soil listed in Tables 5-1 through 5-4, assuming the reasonable occupancy scenario described
above. The same integration time is used to calculate the risk to the RME individual and the
population impacts. The complete set of tables in Appendix K list the collective doses, fatal
cancers and total cancers averted for the various cleanup goals and risk factors for the 12
possible scenarios.
Review Draft - 9/26/94 5-11 Do Not Cite Or Quote
-------
Table 5-5. Fatal Cancers Averted for Reasonable Occupancy Scenario, Cleanup Based on Residential Risk Factors Excluding
Radon Potential Cancer Deaths Averted
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XI 1 1 A
XIIIB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
7 .51E-1
4 . 83E+1
3 .25E-1
2.79E-1
1 . 95E+1
1 .18E+1
2. 13E+0
4 .48E-2
1 . 02E+0
2.64E-2
1. 74E-4
1.56E-4
1.27E-4
2 .18E-3
2 .16E-3
2.11E-3
2.65E-2
2 . 61E-2
2 .52E-2
1.27E-2
1.21E-2
1.09E-2
7.47E-2
7 .41E-2
7 .30E-2
3 .13E+0
3 . 61E+2
2.77E-2
3. 70E+0
3 . 65E+2
1, 000
8 .21E-1
4 .51E+2
3 .60E-1
1.57E+0
2 .13E+1
7 . 88E+1
1.52E+1
3 . 90E-1
3 .21E+0
8. 16E-2
1. 02E-3
6.62E-4
3.58E-4
2 .31E-3
2 .28E-3
2.22E-3
2.93E-2
2 . 88E-2
2 . 75E-2
9.89E-2
7. 03E-2
3.95E-2
7.80E-1
7 . 67E-1
7 .39E-1
3 .11E+1
2 .50E+3
8.73E-2
1.98E+1
2 .52E+3
10, 000
8 .21E-1
2 .22E+3
3 .60E-1
3.04E+0
2 .13E+1
5 .55E+2
1.01E+2
2 .43E+0
3 .55E+0
8.39E-2
2 . 39E-3
l.OOE-3
6.47E-3
2 .31E-3
2 .28E-3
2.22E-3
2.93E-2
2 . 88E-2
2 . 75E-2
7.78E-1
3 . 13E-1
8.91E-1
7.34E+0
6 . 64E+0
5 .38E+0
6 .84E+1
1 .54E+4
1. 12E-1
1.53E+2
1 .56E+4
l.E-5
100
7.38E-1
4 . 82E+1
3 .25E-1
2.76E-1
1 . 95E+1
1 . 1 7E+1
1.78E+0
3 .26E-2
1 . 02E+0
2.64E-2
1.25E-4
1. 12E-4
9. 14E-5
2 . 18E-3
2 . 16E-3
2. 11E-3
2.65E-2
2 . 61E-2
2 .52E-2
8.01E-3
7. 62E-3
6.89E-3
7.47E-2
7 .41E-2
7 .30E-2
3 .13E+0
3 . 60E+2
2.73E-2
3 .63E+0
3 . 64E+2
1, 000
8 . 07E-1
4 .51E+2
3 .60E-1
1.55E+0
2 .12E+1
7 . 88E+1
1.24E+1
2 . 84E-1
3 .21E+0
8. 15E-2
7.29E-4
4.75E-4
2.57E-4
2 . 31E-3
2 .28E-3
2.22E-3
2.93E-2
2 . 88E-2
2 . 75E-2
6.24E-2
4 .43E-2
2.49E-2
7.80E-1
7 . 67E-1
7 .39E-1
3 .10E+1
2 .49E+3
8.56E-2
1 . 95E+1
2 .51E+3
10, 000
8 . 07E-1
2 .22E+3
3 .60E-1
3.00E+0
2 .12E+1
5 .55E+2
8.21E+1
1. 77E+0
3 .55E+0
8.38E-2
1. 71E-3
7. 17E-4
4.64E-3
2 . 31E-3
2 .28E-3
2.22E-3
2.93E-2
2 . 88E-2
2 . 75E-2
4.91E-1
1. 98E-1
5.62E-1
7.34E+0
6 . 64E+0
5 .38E+0
6 .83E+1
1 .54E+4
1.04E-1
1.50E+2
1 .56E+4
l.E-4
100
6 . 97E-1
4 . 82E+1
3.03E-1
2.63E-1
1. 93E+1
1. 17E+1
1.31E+0
1. 12E-2
1. 02E+0
2.63E-2
. OOE+0
.OOE+0
.OOE+0
2 . 18E-3
2 . 16E-3
2. 11E-3
2.65E-2
2 . 61E-2
2 . 52E-2
1.67E-3
1. 59E-3
1.44E-3
7.46E-2
7 .40E-2
7 .29E-2
3 .11E+0
3 .59E+2
2.63E-2
3 .55E+0
3 . 62E+2
1, 000
7. 62E-1
4 .50E+2
3.36E-1
1.48E+0
2 . 10E+1
7. 88E+1
9.01E+0
9. 73E-2
3 . 13E+0
8. 14E-2
. OOE+0
.OOE+0
.OOE+0
2 . 30E-3
2 .28E-3
2.22E-3
2.93E-2
2 . 8 8 E - 2
2 . 75E-2
1.30E-2
9.25E-3
5.20E-3
7. 79E-1
7 . 66E-1
7 .39E-1
3 . 09E+1
2 .49E+3
8. 14E-2
1.90E+1
2 .51E+3
10, 000
7. 62E-1
2 .22E+3
3.36E-1
2.86E+0
2 . 10E+1
5. 55E+2
5.95E+1
6 . 06E-1
3 .46E+0
8.38E-2
. OOE+0
.OOE+0
.OOE+0
2 . 30E-3
2 .28E-3
2.22E-3
2.93E-2
2 . 8 8 E - 2
2 . 75E-2
1.02E-1
4 . 12E-2
1. 17E-1
7.34E+0
6 . 64E+0
5 .37E+0
6 .80E+1
1 .54E+4
8.38E-2
1.45E+2
1 .55E+4
l.E-3
100
5. 60E-1
4 . 82E+1
1.61E-1
2.07E-1
1. 77E+1
1. 15E+1
3.38E-2
. OOE+0
9. 92E-1
2.60E-2
. OOE+0
.OOE+0
.OOE+0
2 . 16E-3
2 . 13E-3
2.09E-3
2.63E-2
2 . 59E-2
2 . 51E-2
3.97E-4
3 . 78E-4
3.42E-4
7.26E-2
7.21E-2
7. 10E-2
2.97E+0
3 . 50E+2
2.60E-2
3.48E+0
3 . 54E+2
1, 000
6 . 12E-1
4 .49E+2
1.78E-1
1. 16E+0
1. 92E+1
7. 83E+1
2.33E-1
. OOE+0
2 . 36E+0
8.04E-2
. OOE+0
.OOE+0
.OOE+0
2 .28E-3
2 .26E-3
2.20E-3
2.91E-2
2 . 86E-2
2 . 73E-2
3. 10E-3
2 .20E-3
1.24E-3
7.58E-1
7.46E-1
7. 19E-1
2.96E+1
2 .45E+3
8.04E-2
1.84E+1
2 .47E+3
10, 000
6 . 12E-1
2 . 19E+3
1.78E-1
2.26E+0
1. 92E+1
5. 52E+2
1.54E+0
. OOE+0
2 . 57E+0
8.27E-2
. OOE+0
.OOE+0
.OOE+0
2 .28E-3
2 .26E-3
2.20E-3
2.91E-2
2 . 86E-2
2 . 73E-2
2.44E-2
9. 82E-3
2.79E-2
7. 14E+0
6 .46E+0
5.23E+0
6.52E+1
1. 52E+4
8.27E-2
1.40E+2
1. 53E+4
l.E-2
100
2 . 51E-1
4 . 65E+1
.OOE+0
.OOE+0
1. 16E+1
1. 02E+1
.OOE+0
. OOE+0
8 . 69E-1
2.46E-2
. OOE+0
.OOE+0
.OOE+0
1. 91E-3
1. 90E-3
1.86E-3
2.30E-2
2 .27E-2
2 . 19E-2
.OOE+0
. OOE+0
.OOE+0
4.94E-2
4 . 90E-2
4 . 82E-2
9.35E-1
2 . 98E+2
2.46E-2
2.73E+0
3 . 01E+2
1, 000
2 . 74E-1
4 . 33E+2
.OOE+0
.OOE+0
1.26E+1
7.24E+1
.OOE+0
. OOE+0
1.43E+0
7.59E-2
. OOE+0
.OOE+0
.OOE+0
2 . 04E-3
2 . 01E-3
1.96E-3
2.55E-2
2 . 50E-2
2 . 39E-2
.OOE+0
. OOE+0
.OOE+0
5. 15E-1
5. 07E-1
4 . 89E-1
1.38E+1
2 . 19E+3
7.59E-2
1.29E+1
2 .20E+3
10, 000
2 . 74E-1
2 . 09E+3
.OOE+0
.OOE+0
1.26E+1
5. 14E+2
.OOE+0
. OOE+0
1. 52E+0
7.81E-2
. OOE+0
.OOE+0
.OOE+0
2 . 04E-3
2 . 01E-3
1.96E-3
2.55E-2
2 . 50E-2
2 . 39E-2
.OOE+0
. OOE+0
.OOE+0
4.85E+0
4 . 39E+0
3 . 56E+0
3.04E+1
1.40E+4
7.81E-2
9.57E+1
1.41E+4
-------
Table 5-6. Fatal Cancers Averted for Reasonable Occupancy Scenario, Cleanup Based on Commercial Risk Factors Excluding
Radon Potential Cancer Deaths Averted
Ref .
c H f- o
bice
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XI 1 1 A
XIIIB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
7.46E-1
4 . 82E+1
3 .25E-1
2.78E-1
1 . 95E+1
1 . 1 7E+1
1.95E+0
3 . 88E-2
1 . 02E+0
2.64E-2
1. 58E-4
1.42E-4
1. 16E-4
2 . 18E-3
2. 16E-3
2. 11E-3
2 . 65E-2
2 . 61E-2
2.52E-2
9. 63E-3
9. 16E-3
8.29E-3
7 .47E-2
7 .41E-2
7.30E-2
3 .13E+0
3 . 61E+2
2.75E-2
3 . 66E+0
3 .64E+2
1, 000
8.15E-1
4 .51E+2
3 . 60E-1
1.56E+0
2.13E+1
7 . 88E+1
1.38E+1
3 . 37E-1
3 .21E+0
8 . 15E-2
9.23E-4
6 . 01E-4
3.25E-4
2 . 31E-3
2.28E-3
2.22E-3
2 . 93E-2
2 . 88E-2
2. 75E-2
7. 50E-2
5. 33E-2
3.00E-2
7 . 80E-1
7 . 67E-1
7.39E-1
3 .11E+1
2 .50E+3
8.68E-2
1 . 96E+1
2.52E+3
10, 000
8.15E-1
2 .22E+3
3 . 60E-1
3.02E+0
2.13E+1
5 .55E+2
9. 16E+1
2 . 10E+0
3 .55E+0
8.39E-2
2 . 17E-3
9. 07E-4
5.87E-3
2 . 31E-3
2.28E-3
2.22E-3
2 . 93E-2
2 . 88E-2
2. 75E-2
5. 90E-1
2 . 37E-1
6.75E-1
7 .34E+0
6 . 64E+0
5.38E+0
6 .84E+1
1 .54E+4
1.09E-1
1 .51E+2
1.56E+4
l.E-5
100
7.22E-1
4 . 82E+1
3 .22E-1
2.71E-1
1. 94E+1
1. 17E+1
1.64E+0
2 . 02E-2
1. 02E+0
2.64E-2
6 . 04E-5
5.42E-5
4.43E-5
2 . 18E-3
2. 16E-3
2. 11E-3
2 . 65E-2
2 . 61E-2
2.52E-2
4 . 19E-3
3 . 98E-3
3.60E-3
7 .47E-2
7 .41E-2
7.30E-2
3 .13E+0
3 . 60E+2
2.68E-2
3 .58E+0
3 .64E+2
1, 000
7.89E-1
4 .50E+2
3 . 56E-1
1.52E+0
2 . 12E+1
7. 88E+1
1. 13E+1
1. 76E-1
3 .21E+0
8 . 15E-2
3 . 54E-4
2 . 30E-4
1.24E-4
2 . 30E-3
2.28E-3
2.22E-3
2 . 93E-2
2 . 8 8 E - 2
2.75E-2
3 .26E-2
2 . 32E-2
1.30E-2
7 . 80E-1
7 . 67E-1
7.39E-1
3 .10E+1
2 .49E+3
8.35E-2
1 . 92E+1
2.51E+3
10, 000
7.89E-1
2 .22E+3
3 . 56E-1
2.94E+0
2 . 12E+1
5. 55E+2
7.49E+1
1. 09E+0
3 .55E+0
8.38E-2
8 . 30E-4
3 .48E-4
2.25E-3
2 . 30E-3
2.28E-3
2.22E-3
2 . 93E-2
2 . 8 8 E - 2
2.75E-2
2 . 56E-1
1. 03E-1
2.94E-1
7.34E+0
6 . 64E+0
5.38E+0
6 .83E+1
1 .54E+4
9.35E-2
1 . 4 7E+2
1.55E+4
l.E-4
100
6.38E-1
4 . 82E+1
2 . 37E-1
2.46E-1
1. 88E+1
1. 17E+1
5. 14E-1
2 . 10E-3
1. 01E+0
2.61E-2
. OOE+0
. OOE+0
.OOE+0
2 . 17E-3
2. 15E-3
2. 11E-3
2 . 65E-2
2 . 61E-2
2.52E-2
4 . 79E-4
4 . 56E-4
4. 12E-4
7.41E-2
7. 35E-2
7.24E-2
3.07E+0
3 . 56E+2
2.61E-2
3 . 52E+0
3.59E+2
1, 000
6.97E-1
4 . 50E+2
2 . 62E-1
1.38E+0
2 . 04E+1
7. 87E+1
3.62E+0
1. 82E-2
2 . 93E+0
8.07E-2
. OOE+0
. OOE+0
.OOE+0
2 . 30E-3
2.27E-3
2.21E-3
2 . 93E-2
2 . 87E-2
2.75E-2
3 . 73E-3
2 . 65E-3
1.49E-3
7. 73E-1
7. 61E-1
7.33E-1
3.06E+1
2 .48E+3
8.07E-2
1. 87E+1
2.50E+3
10, 000
6.97E-1
2 .21E+3
2 . 62E-1
2.68E+0
2 . 04E+1
5. 55E+2
2.39E+1
1. 14E-1
3 .23E+0
8.31E-2
. OOE+0
. OOE+0
.OOE+0
2 . 30E-3
2.27E-3
2.21E-3
2 . 93E-2
2 . 87E-2
2.75E-2
2 . 94E-2
1. 18E-2
3.36E-2
7.28E+0
6 . 59E+0
5.34E+0
6.73E+1
1. 53E+4
8.31E-2
1.43E+2
1.55E+4
l.E-3
100
4.28E-1
4 . 80E+1
3 . 79E-2
4.41E-2
1.45E+1
1. 10E+1
.OOE+0
. OOE+0
9. 61E-1
2.55E-2
. OOE+0
. OOE+0
.OOE+0
2 . 10E-3
2.08E-3
2.04E-3
2 . 54E-2
2 . 50E-2
2.42E-2
1. 81E-4
1. 72E-4
1.56E-4
6 . 37E-2
6 . 32E-2
6.22E-2
2.81E+0
3 . 34E+2
2.55E-2
3 .21E+0
3.37E+2
1, 000
4.68E-1
4 .46E+2
4 . 19E-2
2.48E-1
1. 58E+1
7. 60E+1
.OOE+0
. OOE+0
1. 98E+0
7.89E-2
. OOE+0
. OOE+0
.OOE+0
2 .23E-3
2.20E-3
2. 14E-3
2 . 81E-2
2 . 75E-2
2.64E-2
1.41E-3
1. OOE-3
5.63E-4
6 . 65E-1
6 . 54E-1
6.31E-1
2.81E+1
2 . 38E+3
7.89E-2
1. 63E+1
2.40E+3
10, 000
4.68E-1
2 . 17E+3
4 . 19E-2
4.80E-1
1. 58E+1
5. 37E+2
.OOE+0
. OOE+0
2 . 14E+0
8. 11E-2
. OOE+0
. OOE+0
.OOE+0
2 .23E-3
2.20E-3
2. 14E-3
2 . 81E-2
2 . 75E-2
2.64E-2
1. 11E-2
4 .47E-3
1.27E-2
6 .26E+0
5. 67E+0
4.59E+0
6. 18E+1
1.48E+4
8. 11E-2
1.23E+2
1.49E+4
l.E-2
100
1.09E-1
3 .28E+1
. OOE+0
.OOE+0
4 . 08E+0
7. 71E+0
.OOE+0
. OOE+0
7. 71E-1
8.22E-3
. OOE+0
. OOE+0
.OOE+0
1. 18E-3
1. 17E-3
1. 14E-3
1. 74E-2
1. 71E-2
1.66E-2
. OOE+0
. OOE+0
.OOE+0
2 .28E-2
2 .26E-2
2.22E-2
.OOE+0
2 . 13E+2
8.22E-3
1. 71E+0
2. 14E+2
1, 000
1. 19E-1
3 . 13E+2
. OOE+0
.OOE+0
4 .44E+0
5. 73E+1
.OOE+0
. OOE+0
1. 09E+0
2.54E-2
. OOE+0
. OOE+0
.OOE+0
1.26E-3
1.24E-3
1.21E-3
1. 93E-2
1. 89E-2
1.81E-2
. OOE+0
. OOE+0
.OOE+0
2 . 38E-1
2 . 34E-1
2.25E-1
.OOE+0
1. 62E+3
2.54E-2
6 .44E+0
1.63E+3
10, 000
1. 19E-1
1. 54E+3
. OOE+0
.OOE+0
4 .44E+0
4 . 10E+2
.OOE+0
. OOE+0
1. 14E+0
2.61E-2
. OOE+0
. OOE+0
.OOE+0
1.26E-3
1.24E-3
1.21E-3
1. 93E-2
1. 89E-2
1.81E-2
. OOE+0
. OOE+0
.OOE+0
2 .24E+0
2 . 03E+0
1.64E+0
.OOE+0
1. 09E+4
2.61E-2
4 .46E+1
1.09E+4
-------
Table 5-7. Fatal Cancers Averted for Reasonable Occupancy Scenario, Cleanup Based on Residential Risk Factors Including
Radon Potential Cancer Deaths Averted
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XI I IB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
7 .51E-1
1.42E+2
3 .25E-1
2 . 79E-1
1 . 95E+1
1.18E+1
2 . 13E+0
4.48E-2
1. 02E+0
2 . 64E-2
1.74E-4
1.56E-4
1.27E-4
2.18E-3
2.16E-3
2 .11E-3
2 . 65E-2
2.61E-2
2.52E-2
1.27E-2
1.21E-2
1.09E-2
7 .47E-2
7 .41E-2
7.30E-2
5.95E+0
4 . 74E+2
2.77E-2
3 . 70E+0
4 . 78E+2
1,000
8 .21E-1
1.39E+3
3 .60E-1
1. 59E+0
2.13E+1
7.96E+1
1. 52E+1
3.90E-1
3 .21E+0
8 . 16E-2
1.02E-3
6.64E-4
3 . 60E-4
2.31E-3
2.28E-3
2 .22E-3
2 . 93E-2
2.88E-2
2. 75E-2
1. 02E-1
7.28E-2
4. 18E-2
7 . 80E-1
7 . 67E-1
7.39E-1
5.36E+1
3 .61E+3
8.74E-2
1 . 99E+1
3 . 63E+3
10,000
8 .21E-1
1.14E+4
3 .60E-1
7.47E+0
2.13E+1
8 .42E+2
1. 01E+2
2.43E+0
3 .67E+0
8 . 39E-2
3.01E-3
1.44E-3
6 . 71E-3
2.31E-3
2.28E-3
2 .22E-3
2 . 93E-2
2.88E-2
2. 75E-2
1. 72E+0
9.67E-1
1.25E+0
7 .34E+0
6 . 64E+0
5.38E+0
1.28E+2
3 .15E+4
1. 16E-1
1 . 62E+2
3 . 1 7E+4
l.E-5
100
7 .38E-1
1.42E+2
3 .25E-1
2 . 76E-1
1 . 95E+1
1 . 1 7E+1
1. 78E+0
3.26E-2
1. 02E+0
2 . 64E-2
1.25E-4
1. 12E-4
9. 14E-5
2. 18E-3
2. 16E-3
2 . 11E-3
2 . 65E-2
2.61E-2
2.52E-2
8 . 01E-3
7.62E-3
6.89E-3
7 .47E-2
7 .41E-2
7.30E-2
5.95E+0
4 . 74E+2
2.73E-2
3 . 63E+0
4 . 77E+2
1,000
8 . 07E-1
1.39E+3
3 .60E-1
1. 57E+0
2.12E+1
7.96E+1
1.24E+1
2.84E-1
3 .21E+0
8 . 15E-2
7.31E-4
4.76E-4
2 . 58E-4
2.31E-3
2.28E-3
2 .22E-3
2 . 93E-2
2.88E-2
2. 75E-2
7. 08E-2
4.59E-2
2.64E-2
7 . 80E-1
7 . 67E-1
7.39E-1
5.36E+1
3 .61E+3
8.57E-2
1 . 95E+1
3 . 63E+3
10,000
8 . 07E-1
1.14E+4
3 .60E-1
7. 38E+0
2.12E+1
8 .42E+2
8 .21E+1
1.77E+0
3 .67E+0
8 . 38E-2
2. 16E-3
1.03E-3
4 . 81E-3
2.31E-3
2.28E-3
2 .22E-3
2 . 93E-2
2.88E-2
2. 75E-2
1. 19E+0
6.09E-1
7.87E-1
7.34E+0
6 . 64E+0
5.38E+0
1.28E+2
3 .15E+4
1.06E-1
1 .56E+2
3 . 1 7E+4
l.E-4
100
6 . 97E-1
1.42E+2
3.03E-1
2 . 63E-1
1.93E+1
1. 17E+1
1. 31E+0
1. 12E-2
1.02E+0
2 . 63E-2
.OOE+0
.OOE+0
. OOE+0
2. 18E-3
2. 16E-3
2 . 11E-3
2 . 65E-2
2.61E-2
2.52E-2
1. 67E-3
1.59E-3
1.44E-3
7 .46E-2
7 .40E-2
7.29E-2
5.93E+0
4 . 72E+2
2.63E-2
3 .55E+0
4 . 76E+2
1,000
7. 62E-1
1.39E+3
3.36E-1
1. 50E+0
2. 10E+1
7.95E+1
9. 01E+0
9.73E-2
3. 14E+0
8 . 14E-2
.OOE+0
.OOE+0
. OOE+0
2.30E-3
2.28E-3
2 .22E-3
2 . 93E-2
2.88E-2
2.75E-2
2 . 30E-2
9.58E-3
5.51E-3
7 . 79E-1
7 . 66E-1
7.39E-1
5.34E+1
3 .60E+3
8. 14E-2
1 . 90E+1
3 . 62E+3
10,000
7. 62E-1
1.14E+4
3.36E-1
7. 05E+0
2. 10E+1
8.42E+2
5. 95E+1
6.06E-1
3.57E+0
8 . 38E-2
.OOE+0
.OOE+0
. OOE+0
2.30E-3
2.28E-3
2 .22E-3
2 . 93E-2
2.88E-2
2.75E-2
3 . 87E-1
1.27E-1
1.64E-1
7.34E+0
6 . 64E+0
5.37E+0
1.27E+2
3 .15E+4
8.38E-2
1 . 4 7E+2
3 .16E+4
l.E-3
100
5. 60E-1
1.42E+2
1.61E-1
2 . 07E-1
1.77E+1
1. 15E+1
3 . 38E-2
.OOE+0
9.92E-1
2 . 60E-2
.OOE+0
.OOE+0
. OOE+0
2. 16E-3
2. 13E-3
2 . 09E-3
2 . 63E-2
2.59E-2
2.51E-2
3 . 97E-4
3.78E-4
3.42E-4
7.26E-2
7.21E-2
7. 10E-2
5.75E+0
4.64E+2
2.60E-2
3 .48E+0
4.67E+2
1,000
6 . 12E-1
1.39E+3
1.78E-1
1. 18E+0
1.92E+1
7.90E+1
2 . 33E-1
.OOE+0
2.36E+0
8 . 04E-2
.OOE+0
.OOE+0
. OOE+0
2.28E-3
2.26E-3
2 .20E-3
2 . 91E-2
2.86E-2
2.73E-2
3 . 52E-3
2.28E-3
1.31E-3
7. 58E-1
7.46E-1
7. 19E-1
5. 19E+1
3.56E+3
8.04E-2
1. 84E+1
3.58E+3
10,000
6 . 12E-1
1. 13E+4
1.78E-1
5. 55E+0
1.92E+1
8.38E+2
1. 54E+0
.OOE+0
2.64E+0
8 .27E-2
.OOE+0
.OOE+0
. OOE+0
2.28E-3
2.26E-3
2 .20E-3
2 . 91E-2
2.86E-2
2.73E-2
5. 94E-2
3.03E-2
3.91E-2
7. 14E+0
6 .46E+0
5.23E+0
1.24E+2
3. 12E+4
8.27E-2
1.41E+2
3. 13E+4
l.E-2
100
2 . 51E-1
1.40E+2
.OOE+0
. OOE+0
1. 16E+1
1.02E+1
. OOE+0
.OOE+0
8.69E-1
2 .46E-2
.OOE+0
.OOE+0
. OOE+0
1.91E-3
1.90E-3
1. 86E-3
2 . 30E-2
2.27E-2
2. 19E-2
. OOE+0
.OOE+0
.OOE+0
4 . 94E-2
4 . 90E-2
4.82E-2
4. 13E+0
4. 14E+2
2.46E-2
2 . 73E+0
4. 17E+2
1,000
2 . 74E-1
1.36E+3
.OOE+0
. OOE+0
1.26E+1
7.31E+1
. OOE+0
.OOE+0
1.44E+0
7. 59E-2
.OOE+0
.OOE+0
. OOE+0
2.04E-3
2.01E-3
1. 96E-3
2 . 55E-2
2.50E-2
2.39E-2
6 . 79E-4
.OOE+0
.OOE+0
5. 15E-1
5. 07E-1
4.89E-1
3.93E+1
3.31E+3
7.59E-2
1.29E+1
3.32E+3
10,000
2 . 74E-1
1.09E+4
.OOE+0
. OOE+0
1.26E+1
7.81E+2
. OOE+0
.OOE+0
1.55E+0
7. 81E-2
.OOE+0
.OOE+0
. OOE+0
2.04E-3
2.01E-3
1. 96E-3
2 . 55E-2
2.50E-2
2.39E-2
1. 15E-2
.OOE+0
.OOE+0
4 . 85E+0
4 . 39E+0
3.56E+0
9.37E+1
2.93E+4
7.81E-2
9. 57E+1
2.94E+4
-------
Table 5-8. Fatal Cancers Averted for Reasonable Occupancy Scenario, Cleanup Based on Commercial Risk Factors Including
Radon Potential Cancer Deaths Averted
Ref .
Sits
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XIIIA
XI I IB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR COMMERCIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
7 .46E-1
1.42E+2
3 .25E-1
2 . 78E-1
1 . 95E+1
1 . 1 7E+1
1. 95E+0
3.88E-2
1. 02E+0
2 . 64E-2
1.58E-4
1.42E-4
1. 16E-4
2. 18E-3
2 . 16E-3
2 . 11E-3
2.65E-2
2.61E-2
2 .52E-2
9.63E-3
9. 16E-3
8 .29E-3
7.47E-2
7.41E-2
7 .30E-2
5 . 95E+0
4 . 74E+2
2 . 75E-2
3 .66E+0
4 . 78E+2
1,000
8 .15E-1
1.39E+3
3 .60E-1
1. 58E+0
2.13E+1
7.96E+1
1. 38E+1
3.37E-1
3 .21E+0
8 . 15E-2
9.24E-4
6.02E-4
3 .26E-4
2.31E-3
2 .28E-3
2 .22E-3
2.93E-2
2.88E-2
2 . 75E-2
8.60E-2
5.96E-2
3 . 17E-2
7.80E-1
7.67E-1
7 .39E-1
5 .36E+1
3 .61E+3
8 . 68E-2
1.97E+1
3 . 63E+3
10,000
8 .15E-1
1.14E+4
3 .60E-1
7.44E+0
2.13E+1
8 .42E+2
9. 16E+1
2. 10E+0
3 .67E+0
8 . 39E-2
2.73E-3
1.30E-3
6 . 08E-3
2.31E-3
2 .28E-3
2 .22E-3
2.93E-2
2.88E-2
2 . 75E-2
1.45E+0
7.91E-1
9.46E-1
7.34E+0
6 .64E+0
5 .38E+0
1 .28E+2
3 .15E+4
1. 13E-1
1.59E+2
3 . 1 7E+4
l.E-5
100
7.22E-1
1.42E+2
3.22E-1
2 . 71E-1
1.94E+1
1. 17E+1
1. 64E+0
2.02E-2
1.02E+0
2 . 64E-2
6.04E-5
5.42E-5
4 .43E-5
2. 18E-3
2 . 16E-3
2 . 11E-3
2.65E-2
2.61E-2
2 . 52E-2
4. 19E-3
3.98E-3
3 . 60E-3
7.47E-2
7.41E-2
7 .30E-2
5 . 95E+0
4 . 73E+2
2 . 68E-2
3 .58E+0
4 . 77E+2
1,000
7. 89E-1
1.39E+3
3.56E-1
1. 54E+0
2. 12E+1
7.96E+1
1. 13E+1
1.76E-1
3 .21E+0
8 . 15E-2
3.54E-4
2.31E-4
1.25E-4
2.30E-3
2 .28E-3
2 .22E-3
2.93E-2
2.88E-2
2 . 75E-2
4.60E-2
3.01E-2
1. 38E-2
7.80E-1
7.67E-1
7 .39E-1
5 .35E+1
3 .60E+3
8 . 35E-2
1.93E+1
3 . 62E+3
10,000
7. 89E-1
1.14E+4
3.56E-1
7.25E+0
2. 12E+1
8.42E+2
7.49E+1
1.09E+0
3 .66E+0
8 . 38E-2
1.05E-3
5.00E-4
2 . 33E-3
2.30E-3
2 .28E-3
2 .22E-3
2.93E-2
2.88E-2
2 . 75E-2
7.74E-1
3.99E-1
4 . 12E-1
7.34E+0
6 .64E+0
5 .38E+0
1 .28E+2
3 .15E+4
9.48E-2
1.51E+2
3 .16E+4
l.E-4
100
6 . 38E-1
1.42E+2
2.37E-1
2 .46E-1
1.88E+1
1. 17E+1
5. 14E-1
2. 10E-3
1.01E+0
2 . 61E-2
.OOE+0
.OOE+0
. OOE+0
2. 17E-3
2 . 15E-3
2 . 11E-3
2.65E-2
2.61E-2
2 . 52E-2
4.79E-4
4.56E-4
4 . 12E-4
7.41E-2
7.35E-2
7.24E-2
5. 87E+0
4.69E+2
2 . 61E-2
3.52E+0
4 . 73E+2
1,000
6 . 97E-1
1.39E+3
2.62E-1
1.40E+0
2.04E+1
7.94E+1
3 . 62E+0
1.82E-2
2.93E+0
8 . 07E-2
.OOE+0
.OOE+0
. OOE+0
2.30E-3
2 .27E-3
2 .21E-3
2.93E-2
2.87E-2
2 . 75E-2
4.27E-3
2.96E-3
1. 58E-3
7.73E-1
7.61E-1
7. 33E-1
5 .30E+1
3 .59E+3
8 . 07E-2
1.87E+1
3 . 61E+3
10,000
6 . 97E-1
1. 13E+4
2.62E-1
6 . 59E+0
2.04E+1
8.41E+2
2 . 39E+1
1. 14E-1
3.33E+0
8 . 31E-2
.OOE+0
.OOE+0
. OOE+0
2.30E-3
2 .27E-3
2 .21E-3
2.93E-2
2.87E-2
2 . 75E-2
7. 19E-2
3.94E-2
4 . 71E-2
7.28E+0
6.59E+0
5. 34E+0
1 .26E+2
3 .14E+4
8 . 31E-2
1.44E+2
3 .15E+4
l.E-3
100
4 .28E-1
1.42E+2
3.79E-2
4 .41E-2
1.45E+1
1. 10E+1
. OOE+0
.OOE+0
9.61E-1
2 . 55E-2
.OOE+0
.OOE+0
. OOE+0
2. 10E-3
2 . 08E-3
2 . 04E-3
2.54E-2
2.50E-2
2 .42E-2
1.81E-4
1.72E-4
1. 56E-4
6.37E-2
6.32E-2
6 .22E-2
5.41E+0
4.46E+2
2 . 55E-2
3.21E+0
4 .49E+2
1,000
4 . 68E-1
1.38E+3
4. 19E-2
2 . 51E-1
1.58E+1
7.67E+1
. OOE+0
.OOE+0
1.98E+0
7. 89E-2
.OOE+0
.OOE+0
. OOE+0
2.23E-3
2 .20E-3
2 . 14E-3
2.81E-2
2.75E-2
2 . 64E-2
2.26E-3
1.47E-3
5. 96E-4
6.65E-1
6.54E-1
6 . 31E-1
4 . 90E+1
3.48E+3
7. 89E-2
1.63E+1
3 . 50E+3
10,000
4 . 68E-1
1. 11E+4
4. 19E-2
1. 18E+0
1.58E+1
8. 15E+2
. OOE+0
.OOE+0
2. 19E+0
8 . 11E-2
.OOE+0
.OOE+0
. OOE+0
2.23E-3
2 .20E-3
2 . 14E-3
2.81E-2
2.75E-2
2 . 64E-2
3.82E-2
1.96E-2
1. 78E-2
6.26E+0
5.67E+0
4 . 59E+0
1. 17E+2
3.05E+4
8 . 11E-2
1.23E+2
3 . 06E+4
l.E-2
100
1. 09E-1
1.20E+2
.OOE+0
. OOE+0
4.08E+0
7.71E+0
. OOE+0
.OOE+0
7.71E-1
8 .22E-3
.OOE+0
.OOE+0
. OOE+0
1. 18E-3
1. 17E-3
1. 14E-3
1.74E-2
1.71E-2
1. 66E-2
.OOE+0
.OOE+0
. OOE+0
2.28E-2
2.26E-2
2 .22E-2
. OOE+0
3.00E+2
8 .22E-3
1.71E+0
3 . 02E+2
1,000
1. 19E-1
1. 17E+3
.OOE+0
. OOE+0
4.44E+0
5.79E+1
. OOE+0
.OOE+0
1.09E+0
2 . 54E-2
.OOE+0
.OOE+0
. OOE+0
1.26E-3
1.24E-3
1.21E-3
1.93E-2
1.89E-2
1. 81E-2
.OOE+0
.OOE+0
. OOE+0
2.38E-1
2.34E-1
2 .25E-1
. OOE+0
2.49E+3
2 . 54E-2
6.44E+0
2 . 50E+3
10,000
1. 19E-1
9. 19E+3
.OOE+0
. OOE+0
4.44E+0
6.23E+2
. OOE+0
.OOE+0
1. 16E+0
2 . 61E-2
.OOE+0
.OOE+0
. OOE+0
1.26E-3
1.24E-3
1.21E-3
1.93E-2
1.89E-2
1. 81E-2
.OOE+0
.OOE+0
. OOE+0
2.24E+0
2.03E+0
1. 64E+0
. OOE+0
2.33E+4
2 . 61E-2
4.46E+1
2 . 34E+4
-------
5.3 POTENTIAL RADIOGENIC CANCERS CAUSED BY CLEANUP
The potential radiological impacts resulting from site cleanup include the impact on workers
and the nearby public during cleanup, impacts on the public from the transport of the waste to
a disposal site, and the impacts on the workers and public at the disposal site location. These
short-term impacts could offset some of the long-term impacts averted through cleanup. This
section addresses these issues.
5.3.1 Radiological Impacts on Workers During Cleanup
During site cleanup, workers are exposed to both direct radiation and inhalation of airborne
radioactive soil particles. A key parameter in the calculation of the cumulative dose to
workers is the cumulative level of effort required to remediate a unit volume of contaminated
soil. In this analysis, remediation is assumed to be soil excavation. The analysis is based on
an assumed 1.62 person-hours to excavate, monitor and package one cubic meter of soil (from
NUREG/CR-1754 (Addendum 1), which is in part based on "Superfund Record of Decision:
Monticello Mill Tailings," EPA/ROD/RO8-90/034, August 1990).
The inhalation dose is based on a dust loading of 400 |ig/m3 during excavation (NRC 92).
The outdoor dust loading is highly variable depending on the properties of the soil (especially
moisture content), wind speed and activities at a site that could cause the suspension of dust.
NRC 92 summarizes the literature on dust loading, indicating that the outdoor dust loading
can vary from about 10 to several hundred |ig/m3. For a site with heavy industrial activity, it
is not unusual for the dust loading to exceed several hundred |ig/m3. The OSHA standard for
nuisance dust in the workplace is 10,000 |ig/m3, but the dust level can be maintained well
below this level by using dust suppression techniques, such as wetting the soil with a fine
mist.
Another consideration in modeling dust inhalation is the enhancement or discrimination factor.
In this report, it is assumed that the concentration of the radionuclide on the dust is the same
as in the soil. Studies have shown that, in some cases and for some contaminants, the
concentration of the radionuclides in dust can be either higher (enhancement) or lower
(discrimination) than the concentration in the soil (EGG 84). For example, windblown
suspension picks up the smaller, lower density soil particles, typically less than 50 microns in
diameter (NRC 83). Hence, if the contaminants adhere to soil particles larger than 50
Review Draft - 9/26/94 5-16 Do Not Cite Or Quote
-------
microns, little of the contaminants will be suspended. The converse is also true. If the
radionuclides preferentially adhere to the very small particles, enhancement can occur. For
example, there is evidence that uranium-contaminated soil at uranium mill tailing sites
(NRC 87) and at a radium-contaminated site (Nei 92) have an enhancement factor of about 2
to 3. In this report, an enhancement factor of 1 is used.
The dose attributable to inhalation of suspended dust, DOSInh, may be determined as follows:
DOSInh = RSC x DCFInh x IR x 1.62 x VOL x DL
where:
DOSInh = cumulative effective dose commitment to workers due to inhalation of
suspended dust (person-rem)
RSC = radionuclide soil concentration (pCi/g)
DCFInh = inhalation dose conversion factor (mrem/pCi)
IR = inhalation rate (m3/hr)
1.62 = person-hours of work required to excavate 1 m3 of soil
DL = airborne dust loading
= 400 |ig/m3 (based on a review provided in NRC 92).
VOL = volume of soil being excavated (m3).
The dose attributable to external radiation exposure, DOSExt, may be determined as follows:
DOSExt = RSC x DCFExt x SD x 1.62 x VOL
where:
DOSExt = cumulative worker dose from external radiation on ground during
cleanup (person-rem)
RSC = radionuclide soil concentration (pCi/g)
Review Draft - 9/26/94 5-17 Do Not Cite Or Quote
-------
DCFExt = external dose conversion factor (rem/yr per pCi/cm3)
SD = soil density (1.6 g/cm3)
Total and fatal cancers are calculated in a similar fashion, using the slope factors from EPA's
1993 Health Effects Assessment Summary Tables (EPA 92b). Table 5-9 lists the calculated
incidence of fatal cancers among site remediation workers, using cleanup goals based on
residential risk factors excluding radon. For example, the highest incidence of potential
cumulative radiogenic fatal cancers among workers performing cleanup at Reference Site II is
about 0.1. In other words, there is about a 10% probability of a single radiogenic cancer
death among the worker population as a consequence of cleaning up this site, which is based
on conservative assumptions regarding airborne dust loadings. In fact, dust suppression
techniques will likely reduce these risks. These impacts are compared to the 451 fatal cancers
over the next 1,000 years that can be averted in the general population by cleaning up this
site, based on the reasonable occupancy scenario, as shown in Table 5-5. A comparison of
nationwide totals of worker impacts and cancer deaths averted in the general population, listed
in Tables 5-9 and 5-5, respectively, leads to a similar conclusion. In summary, the results
reveal that the potential radiation doses and risks to workers are extremely small in
comparison to the potential impacts averted due to cleanup.
5.3.2 Off-Site Impacts During Remediation
The dust generated on site during remediation can be transported off site and result in
exposures to nearby members of the public. It can be assumed that dust suppression
techniques and other contamination control procedures will be followed during cleanup, and
airborne monitoring will be performed to ensure that worker and public exposures will be
maintained within existing regulations. Nevertheless, it is appropriate, in support of the cost-
benefit analysis, to estimate these potential impacts.
A two-step process is used to evaluate the impacts. First, a generic analysis is provided
which can be used to represent a broad range of sites. Second, the generic analysis is applied
to a reference site. The overall analysis demonstrates that the potential radiological impacts
off site due to the dust generated during site remediation is small compared to the potential
radiological impacts averted as a result of site cleanup.
Review Draft - 9/26/94 5-18 Do Not Cite Or Quote
-------
Table 5-9. Fatal Cancers Among Remediation Workers, Assuming Residential Risk Factors, Excluding Indoor Radon Potential
Cancer Deaths of Workers
Ref .
c H f- o
bice
No.
I
II
III
IV
V
VI
VII
IX
X
XII
XI 1 1 A
XIIIB
XIIIC
XVIA
XVI B
XVI C
XVI I I A
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXI B
XXI C
XXII
DOE
DOD
NRC
Total
CLEANUP GOAL BASED ON SITE-SPECIFIC RISK OF CANCER INCIDENCE FOR RESIDENTIAL OCCUPANCY/Assessment Period (years)
l.E-6
100
5.92E-3
1 . 03E-1
2 .44E-3
6. 15E-4
1 .54E-1
1 . 97E-2
5. 17E-2
1. 82E-4
1 .24E-4
5.38E-4
3 .22E-7
3 .22E-7
3.22E-7
5 .31E-5
5 .31E-5
5.31E-5
4 .45E-5
4 .45E-5
4 .45E-5
3.73E-5
3 . 73E-5
3 . 73E-5
7.84E-4
7.84E-4
7 . 84E-4
1 . 99E-2
9. 04E-1
5.41E-4
2. 72E-2
9.31E-1
1, 000
5.92E-3
1 . 03E-1
2 .44E-3
6. 15E-4
1 .54E-1
1 . 97E-2
5. 17E-2
1. 82E-4
1 .24E-4
5.38E-4
3 .22E-7
3 .22E-7
3.22E-7
5 .31E-5
5 .31E-5
5.31E-5
4 .45E-5
4 .45E-5
4 .45E-5
3.73E-5
3 . 73E-5
3 . 73E-5
7.84E-4
7.84E-4
7 . 84E-4
1 . 99E-2
9. 04E-1
5.41E-4
2. 72E-2
9.31E-1
10, 000
5.92E-3
1 . 03E-1
2 .44E-3
6. 15E-4
1 .54E-1
1 . 97E-2
5. 17E-2
1. 82E-4
1 .24E-4
5.38E-4
3 .22E-7
3 .22E-7
3.22E-7
5 .31E-5
5 .31E-5
5.31E-5
4 .45E-5
4 .45E-5
4 .45E-5
3.73E-5
3 . 73E-5
3 . 73E-5
7.84E-4
7.84E-4
7 . 84E-4
1 . 99E-2
9. 04E-1
5.41E-4
2. 72E-2
9.31E-1
l.E-5
100
5.81E-3
1 . 03E-1
2 .44E-3
6.07E-4
1 .54E-1
1 . 97E-2
4.32E-2
1. 32E-4
1 .23E-4
5.38E-4
2 . 31E-7
2 . 31E-7
2.31E-7
5. 31E-5
5. 31E-5
5.31E-5
4 .45E-5
4 .45E-5
4 .45E-5
2.35E-5
2 . 35E-5
2 . 35E-5
7.84E-4
7.84E-4
7 . 84E-4
1 . 99E-2
8 . 94E-1
5.40E-4
2. 70E-2
9.22E-1
1, 000
5.81E-3
1 . 03E-1
2 .44E-3
6.07E-4
1 .54E-1
1 . 97E-2
4.32E-2
1. 32E-4
1 .24E-4
5.38E-4
2 . 31E-7
2 . 31E-7
2.31E-7
5. 31E-5
5. 31E-5
5.31E-5
4 .45E-5
4 .45E-5
4 .45E-5
2.35E-5
2 . 35E-5
2 . 35E-5
7.84E-4
7.84E-4
7 . 84E-4
1 . 99E-2
8 . 94E-1
5.40E-4
2. 70E-2
9.22E-1
10, 000
5.81E-3
1 . 03E-1
2 .44E-3
6.07E-4
1 .54E-1
1 . 97E-2
4.32E-2
1. 32E-4
1 .24E-4
5.38E-4
2 . 31E-7
2 . 31E-7
2.31E-7
5. 31E-5
5. 31E-5
5.31E-5
4 .45E-5
4 .45E-5
4 .45E-5
2.35E-5
2 . 35E-5
2 . 35E-5
7.84E-4
7.84E-4
7 . 84E-4
1 . 99E-2
8 . 94E-1
5.40E-4
2. 70E-2
9.22E-1
l.E-4
100
5.49E-3
1 . 02E-1
2 .27E-3
5.79E-4
1. 53E-1
1. 97E-2
3. 18E-2
4 . 54E-5
1. 08E-4
5.38E-4
. OOE+0
. OOE+0
.OOE+0
5. 30E-5
5. 30E-5
5.30E-5
4.45E-5
4 .45E-5
4 .45E-5
4.90E-6
4 . 90E-6
4 . 90E-6
7.83E-4
7.83E-4
7 . 83E-4
1 . 98E-2
8 . 79E-1
5. 38E-4
2.67E-2
9. 06E-1
1, 000
5.49E-3
1 . 02E-1
2 .27E-3
5.79E-4
1. 53E-1
1. 97E-2
3. 18E-2
4 . 54E-5
1.20E-4
5.38E-4
. OOE+0
. OOE+0
.OOE+0
5. 30E-5
5. 30E-5
5.30E-5
4.45E-5
4 .45E-5
4 .45E-5
4.90E-6
4 . 90E-6
4 . 90E-6
7.83E-4
7.83E-4
7 . 83E-4
1 . 98E-2
8 . 79E-1
5. 38E-4
2.67E-2
9. 06E-1
10, 000
5.49E-3
1 . 02E-1
2 .27E-3
5.79E-4
1. 53E-1
1. 97E-2
3. 18E-2
4 . 54E-5
1.20E-4
5.38E-4
. OOE+0
. OOE+0
.OOE+0
5. 30E-5
5. 30E-5
5.30E-5
4.45E-5
4 .45E-5
4 .45E-5
4.90E-6
4 . 90E-6
4 . 90E-6
7.83E-4
7.83E-4
7 . 83E-4
1 . 98E-2
8 . 79E-1
5. 38E-4
2.67E-2
9. 06E-1
l.E-3
100
4.41E-3
1. 02E-1
1.21E-3
4.57E-4
1.40E-1
1. 92E-2
8.23E-4
. OOE+0
6 . 96E-5
5.31E-4
. OOE+0
. OOE+0
.OOE+0
5.23E-5
5.23E-5
5.23E-5
4.42E-5
4 .42E-5
4 .42E-5
1. 16E-6
1. 16E-6
1. 16E-6
7.62E-4
7.62E-4
7. 62E-4
1. 89E-2
8 . 15E-1
5. 31E-4
2.61E-2
8 .42E-1
1, 000
4.41E-3
1. 02E-1
1.21E-3
4.57E-4
1.40E-1
1. 92E-2
8.23E-4
. OOE+0
7. 69E-5
5.31E-4
. OOE+0
. OOE+0
.OOE+0
5.23E-5
5.23E-5
5.23E-5
4.42E-5
4 .42E-5
4 .42E-5
1. 16E-6
1. 16E-6
1. 16E-6
7.62E-4
7.62E-4
7. 62E-4
1. 90E-2
8 . 16E-1
5. 31E-4
2.61E-2
8 .43E-1
10, 000
4.41E-3
1. 02E-1
1.21E-3
4.57E-4
1.40E-1
1. 92E-2
8.23E-4
. OOE+0
7. 69E-5
5.31E-4
. OOE+0
. OOE+0
.OOE+0
5.23E-5
5.23E-5
5.23E-5
4.42E-5
4 .42E-5
4 .42E-5
1. 16E-6
1. 16E-6
1. 16E-6
7.62E-4
7.62E-4
7. 62E-4
1. 90E-2
8 . 16E-1
5. 31E-4
2.61E-2
8 .43E-1
l.E-2
100
1.97E-3
9. 86E-2
. OOE+0
.OOE+0
9. 16E-2
1. 63E-2
.OOE+0
. OOE+0
3 . 01E-5
5.01E-4
. OOE+0
. OOE+0
.OOE+0
4 . 34E-5
4 . 34E-5
4.34E-5
3.86E-5
3 . 86E-5
3 . 86E-5
.OOE+0
. OOE+0
. OOE+0
5. 18E-4
5. 18E-4
5. 18E-4
5. 94E-3
6 . 04E-1
5. 01E-4
1.92E-2
6 .23E-1
1, 000
1.97E-3
9. 91E-2
. OOE+0
.OOE+0
9. 16E-2
1. 63E-2
.OOE+0
. OOE+0
3 . 17E-5
5.01E-4
. OOE+0
. OOE+0
.OOE+0
4 . 34E-5
4 . 34E-5
4.34E-5
3.86E-5
3 . 86E-5
3 . 86E-5
.OOE+0
. OOE+0
. OOE+0
5. 18E-4
5. 18E-4
5. 18E-4
8 . 87E-3
6 .24E-1
5. 01E-4
1.92E-2
6 .44E-1
10, 000
1.97E-3
9. 91E-2
. OOE+0
.OOE+0
9. 16E-2
1. 63E-2
.OOE+0
. OOE+0
3 . 17E-5
5.01E-4
. OOE+0
. OOE+0
.OOE+0
4 . 34E-5
4 . 34E-5
4.34E-5
3.86E-5
3 . 86E-5
3 . 86E-5
.OOE+0
. OOE+0
. OOE+0
5. 18E-4
5. 18E-4
5. 18E-4
8 . 87E-3
6 .24E-1
5. 01E-4
1.92E-2
6 .44E-1
-------
Example Analysis
This section evaluates the risks associated with the release of contaminated dust into the air
during site cleanup at a hypothetical test site. The test site is assumed to have an area of 1 ha
(100 x 100 meters square) and its characteristics are those associated with a typical location in
the Midwest. It will be shown that the results of the generic analysis are equally applicable to
other regions of the country.
The release of contaminated dust emitted from the site was estimated using empirical
correlations given in EPA 85b and EPA 85c. Note that these estimates are highly uncertain,
both because the correlations themselves are very uncertain, and because the input parameters
used here are subjective choices and may not be representative of the actual conditions. EPA
85b points out that these methods are order-of-magnitude estimates for estimating potential
exposure.
EPA 85c gives the following relationship for estimating the dust produced during soil loading,
which is assumed to be the major source of dust suspension during a soil removal operation.
sir u
iQ = 0.0009Jcl 5H 2'2 'I (1)
10 -, ,, ,n ->-> I'
4.6
where,
E10 = kg dust released per Mg of soil handled
k = particle size multiplier = 0.36 for particles < lOjim
s = silt content, percent
U = mean wind speed, m/sec
H = drop height, m
M = soil moisture content, percent
Y = dumping device capacity, m3
Assuming that the silt content is 29 percent, the mean wind speed is 4 m/sec, the drop height
is 2 m, the moisture content is 40 percent, and the dumping device capacity is 2 m3, then,
Review Draft - 9/26/94 5-20 Do Not Cite Or Quote
-------
EiQ = (0.0009) (.36) 5 2l2 ll5
29
I 2^1 T^ |
(2)
2 J [4.6.
= 1.5xlO~5 kg dust/Mg soil dumped
Assuming that the top meter of soil is removed from the 1 ha area and loaded onto trucks,
and that the bulk density of the soil is 1.6 g/cc (1.6 Mg/m3), then there would be 1.6xl04 Mg
of soil removed and (1.6xl04)(1.5xlO"5) = 0.24 kg = 240 g of dust produced.
The rate at which radioactivity is put into the air is the concentration of radionuclide i times
the rate at which dust enters the air, i.e.,
(3)
where,
Qi = release rate of radionuclide i, Ci/yr
ID'12 =pCi/Ci
E10 = rate of dust emission, g/yr
Q = concentration of radionuclide i in soil, pCi/g
Table 5-10 presents the lifetime risk of fatal cancer to an individual located 50 meters from
the site in the worst sector. CAP88-PC was used to estimate the risk, which include the
direct radiation, inhalation, and food ingestion pathways. The default pathway parameters
contained in CAP88-PC were used because they are reasonably representative values. The
meteorology was that of Dayton, Ohio, and the population data was that around the Mound
Laboratory.
Review Draft - 9/26/94 5-21 Do Not Cite Or Quote
-------
Table 5-10
Maximum Lifetime Risk of Fatal Radiological Cancer from Site Cleanup
RADIONUCLIDE
Natural uranium
Co-60
Cs-137
Natural thorium
LIFETIME RISK OF FATAL
CANCER (per pCi/g)*
2xlO'12
6xlO'14
5xlQ-14
3xlO-12
Based on pre-1994 slope factors
Table 5-11 presents the population impacts, expressed in terms of cancer fatalities, for the
first year of exposure following site remediation. Each subsequent year, the number of
impacts decline due to depletion of the contamination by radioactive decay and erosion. The
estimate is based on a total exposed population 2.9xl06 people within a 50-mile (80-
kilometer) radius around the site. The population distribution and tables of %/Q are given in
Table 5-12.
Table 5-11. Total Fatal Cancers Within 80 Kilometer Radius of a Generic Site
Over a 1-year Period Following Site Cleanup (Fatal cancers per year per pCi/g)
RADIONUCLIDE
Natural uranium
Co-60
Cs-137
Natural thorium
Fatal Cancers/pCi/g
2xlO-10
8xlO'12
8xlO'12
2xlO-10
The risk from both ingestion of contaminated food and exposure to off-site contaminated
ground may be somewhat underestimated because the analysis only considered the release of
particles less than 10 jim in size. The ratio of the mass of particles less than 30 |im in size
(particles larger than about 30 |im are not transported very far by the wind) to those less than
10 |im in size is about a factor of 2 judging from the particle size correction factors (k) in
EPA 85b. For natural uranium and thorium, the ingestion and ground pathways account for
Review Draft - 9/26/94
5-22
Do Not Cite Or Quote
-------
Table 5-12. %/Q and Population Distribution Ground-Level %/Q
%/Q Toward Indicated Direction (sec/m3)
Distance (meters)
Dir
N
NNW
NW
WNW
W
WSW
SW
SSW
s
SSE
SE
ESE
E
ENE
NE
NNE
Distance
Dir
N
NNW
NW
WNW
W
WSW
SW
SSW
S
SSE
SE
ESE
E
ENE
NE
NNE
250
2.9E-05
1.5E-05
1.6E-05
1.1E-05
1.6E-05
1.1E-05
8.7E-06
1.2E-05
1.6E-05
1.2E-05
1.2E-05
1.3E-05
2.7E-05
1.4E-05
1.5E-05
1.9E-05
(meters)
15000
3.2E-08
1.6E-08
1.8E-08
1.2E-08
1.7E-08
1.1E-08
9.3E-09
1.2E-08
1.7E-08
1.3E-08
1.3E-08
1.4E-08
3.0E-08
1.5E-08
1.7E-08
2.1E-08
750
3.8E-06
1.9E-06
2.1E-06
1.4E-06
2.0E-06
1.4E-06
1.1E-06
1.5E-06
2.1E-06
1.6E-06
1.5E-06
1.7E-06
3.6E-06
1.8E-06
2.0E-06
2.5E-06
25000
1.5E-08
7.5E-09
8.6E-09
5.7E-09
8.1E-09
5.6E-09
4.3E-09
6.0E-09
7.9E-09
6.3E-09
6.2E-09
6.8E-09
1.4E-08
7.2E-09
8.0E-09
l.OE-08
1500
1.1E-06
5.7E-07
6.4E-07
4.3E-07
6.0E-07
4.2E-07
3.3E-07
4.6E-07
6.2E-07
4.9E-07
4.6E-07
5.1E-07
l.OE-06
5.4E-07
6.0E-07
7.6E-07
35000
9.5E-09
4.7E-09
5.3E-09
3.5E-09
5.0E-09
3.5E-09
2.7E-09
3.7E-09
4.9E-09
3.9E-09
3.8E-09
4.2E-09
8.8E-09
4.5E-09
5.0E-09
6.3E-09
2500
4.7E-07
2.4E-07
2.7E-07
1.8E-07
2.5E-07
1.7E-07
1.4E-07
1.9E-07
2.6E-07
2.0E-07
1.9E-07
2.1E-07
4.5E-07
2.3E-07
2.5E-07
3.2E-07
45000
6.5E-09
3.2E-09
3.6E-09
2.4E-09
3.4E-09
2.4E-09
1.8E-09
2.5E-09
3.3E-09
2.6E-09
2.6E-09
2.9E-09
6.0E-09
3.0E-09
3.4E-09
4.4E-09
3500
2.7E-07
1.3E-07
1.5E-07
l.OE-07
1.4E-07
l.OE-07
8.1E-08
1.1E-07
1.5E-07
1.2E-07
1.1E-07
1.2E-07
2.6E-07
1.3E-07
1.4E-07
1.8E-07
55000
4.6E-09
2.2E-09
2.6E-09
1.7E-09
2.4E-09
1.7E-09
1.3E-09
1.7E-09
2.3E-09
1.9E-09
1.8E-09
2.0E-09
4.3E-09
2.2E-09
2.4E-09
3.1E-09
4500
1.9E-07
9.5E-08
l.OE-07
7.2E-08
l.OE-07
7.0E-08
5.5E-08
7.7E-08
l.OE-07
8.1E-08
7.7E-08
8.6E-08
1.7E-07
9.1E-08
l.OE-07
1.2E-07
70000
2.9E-09
1.4E-09
1.6E-09
l.OE-09
1.5E-09
l.OE-09
8.2E-10
l.OE-09
1.4E-09
1.1E-09
1.1E-09
1.3E-09
2.7E-09
1.4E-09
1.5E-09
2.0E-09
7500
8.7E-08
4.3E-08
4.9E-08
3.3E-08
4.6E-08
3.2E-08
2.5E-08
3.5E-08
4.6E-08
3.7E-08
3.5E-08
3.9E-08
8.2E-08
4.1E-08
4.6E-08
5.8E-08
Review Draft - 9/26/94
5-23
Do Not Cite Or Quote
-------
Table 5-12 (Continued)
Population Data
Distance
Dir
N
NNW
NW
WNW
W
WSW
SW
SSW
s
SSE
SE
ESE
E
ENE
NE
NNE
Distance
Dir
N
NNW
NW
WNW
W
SW
SSW
S
SSE
SE
ESE
E
ENE
NE
NNE
(m)
250
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
593
(m)
15000
45365
4085
3777
2740
2719
18238
35825
7806
5020
1349
3621
20431
55176
103165
103048
750
0
1557
0
0
0
0
0
0
0
0
0
0
0
0
0
0
25000
36184
7707
3380
4133
3932
12638
13221
5822
17157
1619
4905
11472
24453
57218
74061
1500
799
0
1546
0
0
0
0
0
0
0
0
1730
0
0
471
1040
35000
15879
4616
4549
8780
3742
83556
24045
45842
5324
1783
2451
7316
16373
36202
21522
2500
0
0
0
0
2132
0
0
0
767
468
0
0
0
2852
0
1086
45000
30312
7065
5381
4360
3072
17650
169397
72806
14092
8292
13355
6923
6004
23998
7028
3500
0
0
0
0
0
0
0
0
0
0
0
1597
0
0
3898
0
55000
27926
12717
4223
47053
4139
14277
363735
78978
7380
4565
6458
1212
3497
89972
3633
4500
0
0
0
0
0
0
0
0
0
0
0
0
0
2857
2191
0
70000
30986
23106
16238
22798
28587
38926
37915
92117
19412
15152
9075
2238
16057
24474
10815
7500
0
3868
0
0
5966
1009
3102
7666
6473
6677
0
3250
9340
7365
16453
4856
Review Draft - 9/26/94
5-24
Do Not Cite Or Quote
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less than 3 percent of the risk; however, for Cs-137 and Co-60, they account for almost all of
the risk. Thus, the risk estimates given here for Cs-137 and Co-60 may be low by about a
factor of 2. Given the uncertainty in estimating the dust release rate, however, this is not
significant.
Application to the Reference Sites
The generic analysis is based on a 1E4 m2 site where the radionuclide concentrations are 1
pCi/g and the closest off-site resident is 50 meters from the center of the site (i.e., at a 1E4
m2 site, this places the individual at the edge of site). At the reference sites, the radionuclide
concentrations in the contaminated zones range from a few pCi/g to thousands of pCi/g above
background. Multiplying the above results by 1E4 to 1E5 still yields extremely small
individual and population risks.
The reference sites are also much larger than the generic site. However, at the larger sites,
the nearest residents are much farther than 50 meters. These effects tend to offset each other.
For example, if the size of the site increases by a factor of 10, the total release increases 10-
fold. However, atmospheric dispersion also increases substantially with increasing distance.
For example, the highest average annual atmospheric dispersion factor at 50 meters from the
center of the site is 6.6E-4 sec/m3. At greater distances the dispersion factor declines
exponentially as follows:
Distance from Center Atmospheric Dispersion
of Site (m) Factor (sec/m3)
50 6.61xlQ-4
100 1.28xlQ-4
250 2.90X10'5
750 S.SOxlO'6
1500 LlOxlO'6
As applied to the reference sites, the population impacts due to cleanup can be assumed to be
proportional to the radionuclide inventory at the site. The total inventory of each radionuclide
at the generic test site is 0.016 Ci. The actual inventories in contaminated soil at the
reference sites range from a fraction of a curie to several hundred curies of a given
radionuclide. Multiplying the values in Table 5-11 by IxlO5 (i.e., 1000/0.016) yields impacts
Review Draft - 9/26/94 5-25 Do Not Cite Or Quote
-------
that are a small fraction of 1 fatality per year. If the impacts were assumed to remain
constant over a 1,000 year period, the potential impacts are still less than 1 fatality.
Accordingly, it can be concluded that the potential off-site radiological impacts associated
with the site cleanup operation are very small compared to the potential impacts averted due
to cleanup.
5.3.3 Impacts Due to Radiation Exposures During Waste Transport
One disposal option is the packaging and shipping of the waste to a licensed low-level
radioactive waste disposal site. Exposures of the drivers and the public during transport are
due to the direct radiation exposures along the transport route. The duration of these
exposures and the numbers of individuals that may come in close proximity to the transport
vehicle are extremely small in comparison to the numbers of people and exposures associated
with leaving the contaminated soil in place. Specifically, if the soil is not remediated,
members of the public are assumed to be living on top of the soil, ingesting the soil, inhaling
suspended soil particles, and eating food grown in contaminated soil for hundreds to
thousands of years. Accordingly, it is apparent that any radiological impacts caused by the
shipment of the radioactive material will be small in comparison to the impacts averted
through cleanup.
5.3.4 Impacts Associated with Exposures at a Disposal Facility
Both workers and the public can be exposed due to the handling of the waste. However,
since the soil is containerized, and because of properly engineered barriers at the facility, it
can be assumed that the exposures to individuals would be acceptably low.
A more important issue is the long-term exposure of the population following disposal of the
soil. Once the contaminated soil is properly disposed of at a licensed facility, it can be
assumed that no radionuclides will be transported off site as long as the facility is under
institutional control, which is typically assumed to be at least 100 years. Following the period
of institutional control, engineered barriers may begin to degrade and, in time, the
radionuclides will be subject to the same environmental transport processes that they would
have experienced had they never been removed from their original site. Accordingly, in the
long term, the benefits of waste disposal begin to diminish. Nevertheless, since the waste at a
Review Draft - 9/26/94 5-26 Do Not Cite Or Quote
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properly designed disposal site is buried or isolated via engineered barriers, it is expected that
in the long term—over 10,000 years—the potential for radiation exposure of the public from
direct radiation, dust inhalation, plant uptake, and indoor radon would be lower than at the
original site. Similarly, the siting criteria for a licensed, low-level radioactive waste disposal
facility, as set forth in 10 CFR 61 and in the regulations of interstate low-level waste
compacts, minimize the potential for groundwater exposure over the long term, and therefore
offer a potentially important benefit compared to leaving the soil unremediated.
In this report, it is assumed that if the soil is placed in a properly designed waste disposal
facility, it will be isolated from direct human contact by large numbers of individuals
indefinitely and that the potential for groundwater contamination is minimal. This is assumed
whether the soil is disposed of in above- or below-grade engineered facilities.
5.4 RESULTS AND CONCLUSIONS
5.4.1 Benefits vs Volumes of Soil Remediated
Figure 5-1 presents a plot of the volumes of soil remediated to achieve a specified risk-based
cleanup goal as a function of maximum risk of cancer incidence to the RME individual at
Reference Site II. The risks were modeled assuming rural residential occupancy for a 30-year
period some time during the first 1,000 years, excluding the risk caused by indoor radon. The
same figure shows the number of fatal cancers averted by future populations over the same
1,000 years, assuming the reasonable occupancy scenario described in Section 5.2, also
excluding the impacts of indoor radon. In order to demonstrate the benefits of cleanup to
progressively lower risk levels, the vertical axis on the right of the figure indicates
incremental cancer deaths averted, over those averted by cleaning up the site to a 10"2 risk
level. A box at the bottom of the figure indicates that 433 fatal cancers would be averted by
cleanup to a 10"2 risk. Figure 5-2 shows the results of calculations in which both the RME
individual risks and the population impacts averted include the contribution of indoor radon.
Since Ra-226 is a major contaminant at Reference Site II, the radon pathway plays a
significant role in the impacts on future populations.
Appendix L contains comparable figures for all the reference sites. Graphs depicting
calculations both including and excluding the radon pathway are presented for the two sites
with significant contamination by Ra-226: Reference Sites II (duplicates of Figs. 5-1 and 5-2
Review Draft - 9/26/94 5-27 Do Not Cite Or Quote
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Figure 5-1
CO
Q)
"ro
T3
(U
E
CO
*o
(U
_^
o
Reference Site II: 1,000 years, Excluding Rn
Volume of Soil Remediated: Rural Residential
Fatal Cancers Averted: Reasonable Scenario
1E-2
1E-3 1E-4 1E-5
Risk to RME Individual: 1,000-year Residential
Volume Cancers
Radionuclides: Pb-210, Ra-226, Th-230, Ra-228,
Th-228, Th-232, U-234, U-235, U-238
Deaths Averted in Achieving 1E-2 Risk = 4.33E+2
1E-6
-------
Figure 5-2
CO
Q)
"ro
T3
(U
E
= 1.5
o
CO
It—
o
(U
_^
o
0.5
Reference Site II: 1,000 years, Including Rn
Volume of Soil Remediated: Rural Residential
Fatal Cancers Averted: Reasonable Scenario
2.5
2
1E-2
1E-3 1E-4 1E-5
Risk to RME Individual: 1,000-year Residential
Volume Cancers
Radionuclides: Pb-210, Ra-226, Th-230, Ra-228,
Th-228, Th-232, U-234, U-235, U-238
Deaths Averted in Acheiving 1E-2 Risk = 1.36E+3
1E-6
-------
are included in Appendix L for ease of reference) and XXII. Although the radon pathway
plays a small role at sites contaminated by U-234 at which Ra-226 is not a significant
contaminant, the differences in the cleanup levels and in the population impacts averted would
not be noticeable on a graph. In addition, some sites postulated to have three different
environmental settings did not exhibit significantly different modeling results—such trios were
represented by a single member. Included in Appendix L are graphs showing the weighted
totals for all sites, with and without radon. The effects of radon on all sites contaminated
with one or more of its radioactive ancestors are included.
5.4.2 Summary of Fundamental Assumptions
The following summarizes a number of the key assumptions that underlie the central
calculations in this report.
The horizontal axis of each figure refers to the lifetime risk of cancer incidence (not
mortality) to an individual receiving a reasonable maximum exposure (RME) to radiation at
the reference site at the time of peak risk during the first 1,000 years after the site is released
for occupancy.
Assumptions in the Assessment of Risk to the RME Individual
The RME individual occupies the site, and is therefore exposed, for 30 years.
The slope factors used to determine risk as a function of radiation exposure
through different pathways (i.e., exposure to direct radiation, ingestion of
radionuclides, inhalation, etc.) are based on average rates of cancer induction in
a population whose members range in age from 0 to 30 years.
• Whenever the radon pathway is included in the assessment of risk to the RME
individual, it is also included in the calculation of health effects averted by
achieving a cleanup goal based on the individual risk assessment. If radon is
ignored in the individual risk assessment, it is also ignored in the corresponding
determination of health effects averted
• Two post-cleanup modes of occupancy by the RME individual are considered
separately: the rural residential and the commercial/industrial.
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Assumptions in the Determination of Health Effects Averted by Future Populations
• The population is considered to be an average or typical exposed group, not a
group of RME individuals;
The slope factors used in calculating numbers of health effects average risks
over a population of ages from 0 to 70 years;
• Six general population-density/land-use exposure scenarios are considered, as
follows:
low density scenario: 10 people per square kilometer, with or without
crop production;
medium density scenario: 100/km2, with or without crop production;
high density scenario: 1,000/km2, without crop production;
reasonable use scenario, in which the population density at a reference
site reflects that near the real site(s) upon which it was based. The crop
pathway is included for population densities of 300/km2 or less.
There is no need to assume an average period of on-site residence by any
individual as long as the population density and age distribution remain constant
over time.
The risk-based cleanup goal may be based on either rural residential or commercial/industrial
occupancy by the RME individual. For either set of cleanup goals, the population health
effects averted can be modeled by any one (or all) of the six above-mentioned scenarios.
Thus, each of the tables of population impacts in Appendix K reflects a combination of the
RME assumptions which form the basis of risk-based cleanup goals and the scenarios the
evaluate some of the benefits (i.e., population impacts averted) of performing the cleanup.
5.5 SUPPLEMENTARY CALCULATIONS - DOSE-BASED CLEANUP LEVELS
All analyses of site cleanup discussed thus far in this report are of cleanup levels based on
risk to the RME individual. To supplement these calculations, a set of analyses was
performed using identical assumptions and parameters, but based on the annual committed
effective dose equivalent (CEDE) to the same RME individual. The results of these analyses
are found in a set of tables in Appendix M.
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6. Discussion of Sensitivities and Uncertainties in Soil Cleanup Volumes
and Health Impacts Averted
The major objectives of this report are to:
(1) estimate the volume of soil that may require remediation at sites that fall within
the scope of the proposed rule, and
(2) estimate the numbers of potential radiogenic cancers averted as a result of the
remediation of the contaminated soil.
The overall results, as indicated in Tables 5-1 to 5-8 of this report, are that total site cleanup
may require the remediation of up to IxlO8 m3 of soil, and that the total potential number of
radiogenic cancer fatalities averted as a result of the cleanup will be on the order of IxlO4
over 1,000 years. These estimates are sensitive to the assumptions that were used in their
derivation. In addition, given the assumptions, the results are highly uncertain due to
substantial uncertainties in the data, mathematical models, and parameters that were used in
their derivation. This section discusses the sensitivities of the results associated with
alternative modeling assumptions and the uncertainties in the results due to uncertainties in
the overall approach used in their derivation.
6.1 DISCUSSION OF SENSITIVITIES AND UNCERTAINTIES IN THE SOIL
CLEANUP VOLUMES AT REFERENCE SITES
This section discusses the sensitivities and uncertainties in the derived soil cleanup volumes
for the reference sites by evaluating the degree to which the results change using alternative
calculational assumptions and assessing the uncertainties in the soil cleanup volumes for the
real sites upon which the reference sites are based.
"Sensitivities in the soil cleanup volumes" refers to how the cleanup volumes change as a
function of changes in fundamental assumptions regarding the site characteristics and usage
patterns. "Uncertainties in the soil cleanup volumes" refers to the uncertainties in the soil
cleanup volume due to uncertainties in the calculational parameters. The two concepts are not
always clearly distinguishable. However, in general, for real sites, sensitivity analyses are
concerned with issues such as: how do the results change assuming different postulated land
usage patterns, time periods of interest, and cleanup criteria? Uncertainty analyses are
concerned with issues such as: given the land usage patterns, etc., how uncertain are the
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results in light of the uncertainties in key calculational parameters? This section addresses
these issues in a qualitative and semi-quantitative manner.
6.1.1 Overall Sensitivity of the Results
Tables 5-1 through 5-4 (and Appendix K) present estimates of soil cleanup volumes for the
reference sites for a number of cases, as follows:
• Ten alternative risk-based cleanup levels (ranging from IxlO"6 to IxlO"2)
• Risk factors based on three time periods of interest (100, 1000, and 10,000
years)
Risk factors based on two alternative post cleanup land use scenarios (rural
residential and commercial risk factors)
• Risk factors with and without indoor radon
The lower end of the range of risk-based cleanup levels was selected based on consideration
of Superfund guidance which establishes a lifetime risk of IxlO"6 as a point of departure for
site cleanup. The upper end represents the upper bound risk based level that could be used
based on existing regulatory requirements and guidelines. Accordingly, this range essentially
bounds the range of risk-based cleanup levels that are appropriately considered under the
cleanup rule.
The lower end of the time periods of interest represents a judgement that it is unlikely that a
time period of interest less than 100 years would be considered protective given the relatively
long radiological half-lives of many radionuclides. The upper end was selected based on
precedence established by the high level waste rulemaking. The 1000 year time period of
interest is intermediate between these two extremes.
The rural residential scenario was selected because it represents a plausible future use
scenario which results in high end risks. Under this scenario, individuals residing at the site
make extensive use of the site for agricultural purposes and use on-site sources of drinking
water. The commercial use scenario represents a plausible future use scenario where the
potential for exposure is markedly decreased. There are a large number of other plausible
future use scenarios, such as residential without agriculture, recreational uses, and unusual
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demographic settings, such as very high density urban settings. However, the evaluation was
limited to the rural residential and commercial use scenarios because they convey the
potential magnitude of the impacts and the variability in the impacts for two fundamentally
different scenarios. These are plausible scenarios for the reference sites described in
Chapter 4.
The residential scenario without agriculture would result in impacts somewhere between the
rural residential and commercial scenario. A recreational scenario would result in impacts
less than those of the commercial scenario. An extremely high density scenario would
present unique issues. For example, urban settings, such as Manhattan, can have population
densities of 25,000 persons/km2. This greatly increases the potential for exposure. However,
there are also numerous offsetting factors. For example, pavement and large structures shield
against direct radiation, soil ingestion, soil suspension, and infiltration to groundwater. Also,
construction for multistory buildings often requires excavation of large volumes of soil
(thereby removing the contaminated soil) and reduces the potential for indoor radon
exposures, but at the price of increased risk to construction workers.
Risk factors with and without indoor radon were evaluated because it is conceivable that a
separate regulation could be implemented specifically for indoor radon. Accordingly, it is
desirable to evaluate differences in cleanup volumes with and without explicit consideration
of the risks from indoor radon.
The different cases addressed in this report represent a type of quantitative sensitivity
analysis. Inspection of the "totals" in Tables 5-1 to 5-4 and Appendix K reveals the
following:
1. The total cleanup volume is virtually independent of the time period of interest used to
derive the risk factors. Recognizing that the cleanup volume is determined by the
contamination pattern and the RME risk factors, the reason this occurs is the risk
factors are virtually unchanged for the different time periods of interest. This occurs
because the peak dose to the RME individual is delivered within a relatively short time
after he or she takes occupancy at the site.
2. The use of rural residential as opposed to commercial risk factors results in an
approximate 2 to 5-fold greater volume of soil that may require remediation. This
occurs because the risk factors for the RME individual are generally about 3 times
higher for the rural residential as opposed to the commercial scenarios. The
approximate three-fold difference in the risk factors is primarily related to the
approximately three-fold difference in occupancy times for the two scenarios.
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3. The total cleanup volume is only slightly reduced by eliminating indoor radon from
the derivation of the risk factors. The reason is, in the aggregate, the volume of soil
addressed in this report containing elevated levels of Ra-226 is relatively small. Even
for sites with significant Ra-226 contamination, the differences in the cleanup volume
with and without consideration of the risks due to indoor radon are small. The largest
difference is at Reference Site XXII, where the difference is a factor of approximately
3, and this only occurs at a cleanup level of IxlO"2.
4. The volume of soil that may require remediation changes by over a factor of 10 as the
cleanup level is varied from IxlO"2 to IxlO"6. The reason is, the lower the risk-based
cleanup level, the lower the cleanup concentration, and, since the volume of
contaminated soil at the reference sites is generally greatest at the lower
concentrations, the cleanup volume increases as the cleanup level is made more
restrictive.
The last observation is critical to the rulemaking effort because it reveals that the potential
cost of remediation depends, at least in part, on the risk-based cleanup level. Table 6-1,
which is summarized from Appendix K, demonstrates the relationship between the cleanup
level and cleanup volume.
Table 6-1. Total Soil Volume Requiring Remediation
Risk-Based Cleanup Level
IxlO-6
IxlO-5
IxlO'4
lxlO'3
lxlO'2
Soil Volume Potentially Requiring Remediation (ri)
Rural Residential Risk Factors
With Radon
l.OOxlO8
4.88x10'
2.75x10'
1.17x10'
4.24X106
Without Radon
9.95x10'
4.77x10'
2.67x10'
1.10x10'
3.07X106
Commercial Risk Factors
With Radon
6.43x10'
3.75x10'
1.72x10'
6.84X106
7.59X105
Without Radon
6.28x10'
3.64x10'
1.64x10'
6.64X106
6.25x10=
Figure 6-1 presents these results graphically.
Review Draft - 9/26/94
6-4
Do Not Cite or Quote
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vo
ON
a
o
S
O
W
o
o
g
f?
Figure 6-1. Soil Cleanup Volumes
U.S. Total
Cubic Meters of Soil
1,000,000,000
1E-6
1E-5 1E-4 1E-3
Risk-Based Cleanup Goal
Resid/Rn
Not Including Diffuse NORM
Resid/No Rn
Comm/Rn
Comm/No Rn
1E-2
-------
6.1.2 Discussion of Uncertainties in Soil Cleanup Volumes
The uncertainties in the calculated soil cleanup volumes presented in Tables 5-1 to 5-4 are a
result of uncertainties associated with each of the steps used in their derivation. In all cases,
the uncertainty in the cleanup volume is dominated by uncertainty in the estimate of the
volume of the contaminated soil and the radionuclide concentration distributions in the soil
for the real sites which formed the bases for the reference sites. Figures 4-4 through 4-25
present the assumed contaminated soil volumes and radionuclide concentration distributions
at each reference site. A separate discussion of the uncertainties in these distributions is
provided in Section 4.
A second major source of uncertainty in the cleanup volume is uncertainty in the site-specific
risk factors which are used to derive the site-specific cleanup concentrations required to
achieve a given risk-based cleanup level. Uncertainty in the site-specific risk factors are due
to uncertainties in the patterns of contamination, the environmental characteristics, and the
extent to which the site will be used following cleanup. Tables 6-2a and 6-2b present the site-
specific risk factors and dose factors for each site as derived using RESRAD and the
assumptions described in Section 4. These are the individual radionuclide risk factors at the
time of the peak dose rate at the site. Table 6-3 presents the peak risk factors for each
radionuclide as if they were the only radionuclide at the site. Table 6-3 sorts the site-specific
risk factors by isotope and compares them to the generic risk factors. This comparison
provides insight into the magnitude of the variability of risk factors among the different
reference sites.1
For Cs-137, the variability among sites is small, less than a factor of 2. The reason is the risk
from Cs-137 is virtually entirely due to direct radiation which is dependent only on the
thickness of the contaminated zone. This is also true for Co-60 and Ra-228. In general, the
risk factors for strong gamma emitters remain constant for contaminated zone thicknesses in
excess of 15 to 20 cm because any contamination at greater depths is shielded by the
overlying soil. However, as the thickness is reduced below 15 cm, the risk factor begins to
decrease. For example, the risk factor at 5 cm is about one half that at 15 cm. (See Section
3.6 which presents the relative dose rate of selected gamma emitters as a function of the
The risk factors in Table 6-3 are often slightly higher than those in Table 6-2 because the different
radionuclides at a site do not necessarily peak at the same time. Hence, the peak risk factor for a
radionuclide can be higher when it is at a site by itself than when it is at a site commingled with other
radionuclides that have different peaking times. In addition, Table 6-3 is based on a more recent version
of RESRAD which also contributes to the small differences between the values in Table 6-2 and 6-3.
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Table 6-2a. Residential Scenario Maximum Health Impact Per Unit Concentration
(Total Cancers per pCi/g) for a 1,000 Year Period
Reference
Site No.
I
II- 1 to II-7
II-2
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
Nuclide
Cs-137
Pb-210
Ra-226
Th-230
Ra-228
Th-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
U-238
U-235
U-234
With Radon
Pathway
2.66E-05
9.26E-06
3.12E-04
2.63E-05
9.76E-05
1.64E-04
3.44E-07
4.52E-07
7.51E-06
2.03E-06
1.27E-07
4.60E-06
8.32E-07
2.66E-05
2.74E-07
6.52E-06
1.41E-06
2.66E-05
2.66E-05
1.27E-07
4.60E-06
8.32E-07
1.96E-07
2.88E-07
3.03E-05
1.63E-07
2.48E-07
2.52E-05
3.02E-05
2.04E-05
6.61E-07
7.87E-07
1.17E-06
5.84E-06
2.02E-07
1.17E-06
5.84E-06
2.02E-07
1.17E-06
5.84E-06
2.02E-07
Excluding
Radon Pathway
2.66E-05
9.26E-06
1.92E-04
2.06E-05
9.76E-05
1.64E-04
3.44E-07
4.52E-07
7.51E-06
2.03E-06
1.27E-07
4.60E-06
8.32E-07
2.66E-05
2.74E-07
6.52E-06
1.41E-06
2.66E-05
2.66E-05
1.27E-07
4.60E-06
8.32E-07
1.96E-07
2.88E-07
3.03E-05
1.63E-07
2.48E-07
2.52E-05
3.02E-05
2.03E-05
6.61E-07
7.87E-07
1.17E-06
5.84E-06
2.02E-07
1.17E-06
5.84E-06
2.02E-07
1.17E-06
5.84E-06
2.02E-07
Review Draft - 9/26/94
6-7
Do Not Cite or Quote
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Reference
Site No.
I
XVIA
XVIB
XVIC
XVIIIA
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
Nuclide
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Ra-228
Th-228
Th-232
Ra-228
Th-228
Th-232
Ra-228
Th-228
Th-232
Ra-226
Th-232
Th-228
U-234
U-235
U-238
Pb-210
Ra-228
With Radon
Pathway
2.66E-05
2.04E-04
4.95E-05
2.04E-04
4.95E-05
2.04E-04
4.95E-05
4.73E-05
4.39E-06
4.73E-05
4.39E-06
4.73E-05
4.39E-06
1.20E-06
6.49E-06
1.72E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
1.14E-03
3.63E-07
1.67E-04
2.43E-05
2.73E-05
3.60E-05
1.50E-05
1.06E-04
Excluding
Radon Pathway
2.66E-05
2.04E-04
4.95E-05
2.04E-04
4.95E-05
2.04E-04
4.95E-05
4.73E-05
4.39E-06
4.73E-05
4.39E-06
4.73E-05
4.39E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
5.28E-07
7.59E-06
2.15E-06
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
1.05E-04
1.67E-04
3.55E-07
2.03E-04
3.62E-07
1.67E-04
2.41E-05
2.73E-05
3.60E-05
1.50E-05
1.06E-04
Review Draft - 9/26/94
6-8
Do Not Cite or Quote
-------
Table 6-2b. Residential Scenario Dose Rate Per Unit Concentration
(mrem/yr pCi/g) for a 1,000 Year Period
Reference
Site No.
I
II- 1 to II-6
II-2
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
Nuclide
Cs-137
Pb-210
Ra-226
Th-230
Ra-228
Th-228
Th-232
U-234
U-235
U-238
U-234
U-235
U-238
Cs-137
U-234
U-235
U-238
Cs-137
Cs-137
U-234
U-235
U-238
Pu-239
Am-241
Cs-137
Pu-239
Am-241
Tc-99
U-238
U-234
Pu-239
Am-241
U-238
U-235
U-234
U-238
U-235
U-234
U-238
U-235
U-234
With Radon
Pathway
1.23E+00
1.59E+00
2.49E+01
1.92E+00
5.32E+00
6.90E+00
6.94E-01
7.49E-02
5.32E-01
1.35E-01
2.24E-02
3.13E-01
5.06E-02
1.23E+00
4.80E-02
4.52E-01
9.23E-02
1.23E+00
1.23E+00
2.24E-02
3.13E-01
5.06E-02
1.12E-01
1.31E-01
1.40E+00
9.29E-02
1.10E-01
3.76E-01
2.29E+00
2.39E+00
3.77E-01
4.06E-01
7.35E-02
4.01E-01
3.54E-02
7.35E-02
4.01E-01
3.54E-02
7.35E-02
4.01E-01
3.54E-02
Excluding Radon
Pathway
1.23E+00
1.59E+00
8.98E+00
1.12E+00
5.32E+00
6.90E+00
6.94E-01
7.49E-02
5.32E-01
1.35E-01
2.24E-02
3.13E-01
5.06E-02
1.23E+00
4.80E-02
4.52E-01
9.23E-02
1.23E+00
1.23E+00
2.24E-02
3.13E-01
5.06E-02
1.12E-01
1.31E-01
1.40E+00
9.29E-02
1.10E-01
3.76E-01
2.29E+00
2.38E+00
3.77E-01
4.06E-01
7.35E-02
4.01E-01
3.54E-02
7.35E-02
4.01E-01
3.54E-02
7.35E-02
4.01E-01
3.54E-02
Review Draft - 9/26/94
6-9
Do Not Cite or Quote
-------
Reference
Site No.
I
XVIA
XVIB
XVIC
XVIIIA
XVIIIB
XVIIIC
XXA
XXB
XXC
XXIA
XXIB
XXIC
XXII
Nuclide
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Co-60
Cs-137
Cs-137
Sr-90
Cs-137
Sr-90
Cs-137
Sr-90
U-234
U-235
U-238
U-234
U-235
U-238
U-234
U-235
U-238
Ra-228
Th-228
Th-232
Ra-228
Th-228
Th-232
Ra-228
Th-228
Th-232
Ra-226
Th-232
Th-228
U-234
U-235
U-238
Pb-210
Ra-228
With Radon
Pathway
1.23E+00
9.34E+00
2.28E+00
9.34E+00
2.28E+00
9.34E+00
2.28E+00
2.21E+00
2.60E-01
2.21E+00
2.60E-01
2.21E+00
2.60E-01
1.55E-01
6.10E-01
1.15E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
1.35E+02
7.28E-01
7.04E+00
2.85E+00
2.94E+00
2.73E+00
2.58E+00
6.15E+00
Excluding Radon
Pathway
1.23E+00
9.34E+00
2.28E+00
9.34E+00
2.28E+00
9.34E+00
2.28E+00
2.21E+00
2.60E-01
2.21E+00
2.60E-01
2.21E+00
2.60E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
8.34E-02
5.38E-01
1.43E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
5.98E+00
7.04E+00
7.12E-01
9.78E+00
7.28E-01
7.04E+00
2.83E+00
2.94E+00
2.73E+00
2.58E+00
6.15E+00
Review Draft - 9/26/94
6-10
Do Not Cite or Quote
-------
thickness of the contaminated zone based on the external dose conversion factors tabulated in
Federal Guidance Report No. 12). Uncertainties regarding the hydrogeological characteristics
of the site, dust suspension factors, or the extent to which the site is or is not used for
agricultural purposes do not contribute to uncertainties in the risk factor for sites contaminated
with Cs-137 or other strong gamma emitters. This is an important observation because the
risk factors among sites for strong gamma emitters will be similar, which implies that a simple
set of cleanup concentrations may be broadly applicable to most sites contaminated with
strong gamma emitters.
The risk from Ra-226 is primarily due to indoor radon. The buildup of indoor radon is highly
site-specific and cannot be reliably predicted for individual homes. As a result, the
relationship between the Ra-226 concentration in soil and indoor radon levels is based on
simplified models and default assumptions which are designed to result in reasonable values
for most sites. However, the risk factors could be significantly higher or lower for many sites.
Section 3.2.2 describes the variability in the relationship between indoor radon and the
concentration of Ra-226 in soil. Given the default modeling parameters, the major contributor
to uncertainty in the risk factor is the average Ra-226 concentration in the soil adjacent to the
home. In general, it is the concentration of Ra-226 over an approximate 5 meter depth that
controls the indoor radon concentration. When the contaminated zone is thin, the contribution
of the indoor radon to the risk decreases and the risks from direct radiation become
comparable to that of indoor radon. This is the main reason for the variability in the risk
factors for Ra-226 in Table 6-3.
The risk factors for uranium in Table 6-3 fall into two groups, those sites where the uranium
reaches the water table within the time period of interest and those sites where it does not. At
sites where it reaches the groundwater, the risk factor is about 10 times greater. At sites
where it does not reach the aquifer, the direct radiation, dust inhalation, and crop ingestion
pathways dominate. Accordingly, a source of uncertainty in modeling the risks of uranium is
uncertainty in the time required for uranium to reach groundwater resources. The uncertainty
in the time required to reach groundwater is dependent on the uncertainties associated with
the Kd value for uranium and the hydrogeologic characteristics of the site (i.e., hydraulic
conductivity, residual saturation, infiltration, etc.).
The key pathway for Pu-239 is dust inhalation. As a result, the primary contributor to
uncertainty is the airborne dust loading. This value is highly site-specific and difficult to
reliably predict. (See Section 3.2 for a discussion of the variability of the dust loading). As a
result, a conservative value of 200 //g/m3 is used to model the risk from dust inhalation at all
Review Draft - 9/26/94 6-11 Do Not Cite or Quote
-------
sites. This is an upper end value as applied to long term exposures in non-urban settings
(ANL 93b). Given this assumption, the primary contributor to uncertainty in the risk factor
for Pu-239 is uncertainty in the thickness of the contaminated zone. This occurs because the
dust inhalation model is based on the assumption that the radionuclide concentration in the
airborne dust is the average radionuclide concentration in the top 15 cm of soil. Accordingly,
if the contaminated zone is only a few cm, the risk per pCi/g will be several times smaller
than at sites where the thickness of the contaminated zone exceeds 15 cm. The variability in
the Pu-239 risk factors in Table 6-3 is due to differences in the thicknesses of the
contaminated zones modeled at the sites.
In the following sections, the uncertainties in the cleanup volumes of each site are discussed.
Each section is divided into three parts. The first part discusses the contamination patterns for
each site as presented in Figures 4-4 to 4-25. Reference is then made to the RESRAD derived
risk factors provided in Table 6-2. These risk factors are used to derive the isotope-specific
cleanup concentrations required to achieve a cleanup level of IxlO"4 for each site. These
cleanup concentrations are then applied to the appropriate figures characterizing the soil
contamination pattern in order to estimate the soil cleanup volume required to achieve a risk
level of 1x10"4. These graphically derived cleanup volumes are then compared to the
mathematically interpolated cleanup volumes in Table 5-3. Table 5-3 is used in the
evaluation because it includes indoor radon and it is based on the more conservative rural
residential risk factors (i.e., the upper end case). In addition, the discussion keys in on the
IxlO"4 cleanup level because it is in the mid range of the risk levels addressed and its use as a
health-based cleanup level under CERCLA. The purpose of this exercise is to confirm the
cleanup volumes reported in Table 5-3, given the site-specific risk factors derived using
RESRAD.
The next step is an independent derivation of the RESRAD derived risk factors. This is
accomplished through the use of hand calculations which accomplish two objectives. First,
the calculations confirm the RESRAD derived values, and second, they explicitly identify the
key parameters and assumption used to derive the risk factors.
The third step in the analysis is a discussion of the uncertainties in the key parameters used to
derive the site-specific risk factors. The discussion explores how the cleanup volumes may
change as a function of alternative calculational assumptions and the uncertainties in the
values of the calculational parameters.
The overall analysis serves not only as a sensitivity and uncertainty analysis, but also serves
as a type of quality assurance check on the computer derived estimates of the soil cleanup
volumes presented in Table 5-3.
Review Draft - 9/26/94 6-12 Do Not Cite or Quote
-------
Table 6-3
Comparison of Risk Factors
Ref.
Site
I
II- 1
II-2
III
IV
V
VI
VII
IX
X
XII
XIIIA
XIIIB
XIIIC
XVIA,
B&C
XVIII
A.B&C
XXA.B
&C
XXIA,
B&C
XXII
Generic
Site*
Risk Factors ( ifetime risk of cancer/pCi/g - 30 year slope factors - rural residential scenario)
Th-228
1.71xlQ-4
1.74xlCr4
1.68xlQ-4
Th-232
2. 99x1 Q-4
3.04xlCr4
2.95xlQ-4
Cs-137
2.82xlQ-5
2.82xlOJ
2.82xlO-5
2.82xlO-5
3.22xlCT5
S.OlxlO-5
4.86xlQ-5
7.30xlQ-5
Ra-226
with Rn
3.29xlCT4
1.1 7x1 0J
l.llxlOJ
Ra-226
no Rn
2.14x10
2.49x10
2.38x10
Th-230
with Rn
2.75x10
-5
2.11x10
-4
Th-230
no Rn
2.20x10
7.50x10
U-234
6.74x10"
1.70x10-
3.65x10"
1.69x10-
4.73x10"
2.69x10"
2.69x10-
2.69x10"
8.58x10-
2.48x10-
5
1.85x10"
5
U-235
7.38x10"
6
4.65x10-
6
6.62x10"
6
4.68x10-
6
5.92x10"
6
5.92x10-
6
5.92x10"
6
7.90x10-
6
2.78x10-
5
2.41x10"
U-238
2.36x10"
6
8.95x10-
1.55x10"
6
8.95x10-
7
7.05x10"
6
1.27x10"
6
1.27x10-
6
1.34x10"
6
2.64x10-
6
3.67x10-
5
2.84x10"
Pu-239
2.26x10"
1.88x10-
9.85x10-
7
9.58x10"
Am-241
3.16x10"
2.71x10-
1.12x10-
6
1.11x10-
6
Tc-99
2.65x10"
5
5.51x10"
Co-60
2.04x10-
2.69x10"
Sr-90
1.01x10-
5
8.06x10"
5
Ra-228
1.73x10
1.79x10
1.06x10
1.78x10
-------
Reference Site I
Reference Site I is based in part on information characterizing the Hanford Reservation. Figure 4-4
presents the radionuclide contamination pattern for soil used in this analysis, which, in turn, was based
primarily on aerial survey data. As indicated in Section 4.4.3, numerous assumptions and extrapolations
were made in order to derive this contamination pattern. For example, the aerial survey contour lines are
assumed to be indicative of soil contamination. The contour lines may, at least in part, reflect radiation
fields created by large inventories of localized buried or stored material. The contaminated soil may not
be dispersed but localized in the vicinity of the pits and trenches. In addition, the soil at the site is known
to be contaminated with radionuclides other than Cs-137. Work is proceeding to obtain specific
information characterizing soil contamination at Hanford. For these reasons, this report employs the
concept of a reference site and does not claim that the analyses are accurate representations of the soil
contamination pattern at the real sites, in this case Hanford. Until better data characterizing the
contamination pattern at the real sites are available, any attempt at assigning an uncertainty distribution to
the contamination patterns would be highly speculative.
Notwithstanding the difficulties in characterizing the uncertainties in the actual volumes of
contaminated soil and the radionuclide distributions at a given site, some general conclusions
can be drawn. First, all else being equal, the cleanup volume is proportional to the
contaminated soil volume and the average radionuclide concentration in the soil.
Accordingly, the tabulated estimates of cleanup volumes can be prorated as new information
is acquired regarding the contaminated soil volume or average radionuclide concentration at a
given site. If other radionuclides are determined to be present at a site, the degree to which
they may influence the cleanup volume will be a function of the volume of soil contaminated
with the radionuclides, the average concentrations of the radionuclides in the soil, and the
radionuclide risk factors. As a rule of thumb, the product of the soil volume, the average
radionuclide concentration, and the risk factor for a given radionuclide is a convenient index
for determining the degree to which any radionuclide could substantively influence the
estimates of the soil cleanup volume at a given site. For example, it is known that U-238 is
present in the soil at Hanford. However, because its risk factor is at least 10 times smaller
than that of Cs-137, its average concentration in the contaminated soil volume used in the
analysis would have to be about 10 times greater than that of Cs-137 before it could
significantly influence the volume of soil that needs to be remediated at Reference Site I.
Review Draft - 9/26/94 6-14 Do Not Cite or Quote
-------
Given the pattern of soil contamination, the uncertainty in the soil cleanup volume derived for
Reference Site I is due to the uncertainty in the RESRAD derived site-specific risk factor for
Cs-137, i.e., 2.66xlO"5 lifetime risk of cancer per pCi/g (see Table 6-2). The risk factor is
used to determine the soil cleanup concentration level, which is then used to derive the
cleanup soil volume. For example, if the cleanup level is IxlO"4, the soil cleanup
concentration, as derived using the risk factor for Cs-137 for Reference Site I, is about 3.6
pCi/g (i.e., lxlCT4/2.66xlCT5). Note that in Figure 4-4, 3.6 pCi/g corresponds to about 4xl05
m3. Also note that the actual value reported in Table 5-3 for a cleanup level of IxlO"4, which
is based on curve fitting and mathematical interpolation, is 4.66xl05 m3.
Disregarding the uncertainty in the estimate of the soil contamination volume and
radionuclide distribution at Hanford, uncertainty in the cleanup volume for Reference Site I
depends on the uncertainty in the risk factor for Cs-137. For example, if the risk factor were
10 times higher, the cleanup concentration would be 0.36 pCi/g, which is in the range of
background. As a result, the cleanup volume would be the entire volume of contaminated soil
at the site. As a general rule, the entire volume of contaminated soil at any site is that volume
which is clearly and unambiguously above background.2 This would be about IxlO6 m3 at
Reference Site I. If the risk factor were 10 times smaller, the cleanup concentration would be
36 pCi/g, and the cleanup volume would be about IxlO5 m3 (see Figure 4-4).
Hence, at this site, given the contamination pattern, the cleanup volume would range from
IxlO6 m3 to IxlO5 m3 depending on whether the risk factor were either 0.36 pCi/g to 36 pCi/g.
The question is, what is the uncertainty in the risk factor?
The risk factor for Cs-137 for Reference Site I was derived using RESRAD and the input
assumptions described in Section 4. Inspection of Figure 6-2, which was constructed from
the RESRAD run, reveals that the risk is virtually entirely due to direct external radiation. As
a result, the risk factor is independent of all site-specific characteristics except those
specifically pertaining to the calculation of external exposure risk. The key parameters
include the area and thickness of the contaminated zone and the external exposure slope
factor (the uncertainty in the external exposure slope factor is a combination of the
uncertainty in the external dose conversion factor and the risk conversion factor).
Such a determination must often be defined and implemented based on geostatistical considerations,
which could require extensive sampling to confirm the absence of a contaminant above a relatively large
and variable background.
Review Draft - 9/26/94 6-15 Do Not Cite or Quote
-------
Figure 6-2
1.E+01
1.E+00
1.E-I
E
&
50 (c)
(a)
(b)
(c)
Inhalation
i.
i.
9.
7.
5.
4.
3.
2.
9.
4.
0.
Total
23E+00
17E+00
76E-01
67E-01
93E-01
49E-01
31E-01
34E-01
18E-02
06E-02
OOE+00
Ground
1.18E+00
1.13E+00
9.42E-01
7.41E-01
5.73E-01
4.35E-01
3.21E-01
2.27E-01
8.91E-02
3.95E-02
0. OOE+00
Meat Milk
3.01E-02 1.07E-02 3
2.86E-02 1.01E-02 3
2.33E-02 8.24E-03 2
1.78E-02 6.30E-03 1
1.34E-02 4.74E-03 1
9.88E-03 3.50E-03 1
7.08E-03 2.51E-03 7
4.87E-03 1.73E-03 5
1.80E-03 6.38E-04 1
7.75E-04 2.74E-04 8
0. OOE+00 0. OOE+00 0
Plant
.16E-03
.OOE-03
.44E-03
.87E-03
.41E-03
.04E-03
.43E-04
.11E-04
.89E-04
.13E-05
.OOE+00
Water independent inhalation pathway excludes radon
"Others" includes the
all
i.
i.
i.
i.
8.
6.
4.
3.
1.
4.
0.
Soil
90E-04
81E-04
47E-04
12E-04
45E-05
23E-05
47E-05
07E-05
14E-05
89E-06
OOE+00
(a) Others (b)
4
3
3
2
1
1
9
6
2
1
0
.05E-06
.85E-06
. 13E-06
.40E-06
.80E-06
.33E-06
.52E-07
.55E-07
.42E-07
.04E-07
.OOE+00
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
inhalation.
following pathways: Radon (water independent and dependent), and
the water dependent pathways (water, fish,
Dose rates
plant, meat,
and milk).
for all pathways are equal to 0. OOE+00 for times between
50 and 10
,000 years.
Review Draft - 9/26/94
6-16
Do Not Cite Or Quote
-------
Though RESRAD was used to derive the risk factors, for any one radionuclide and pathway it
is possible to derive the risk factor using simple hand calculations. Such calculations are
useful because they serve as an independent check on the computer runs and explicitly reveal
the role of each parameter in the calculation.
For a site contaminated with Cs-137, the lifetime risk of cancer is derived using the following
equation for external exposure to contaminated soil:
Risk = C x SF x t x AF1 x AF2 x AF3
where:
Risk = Risk based cleanup level (for this example, assume IxlO"4 lifetime risk
of cancer)
C = Average Cs-137 concentration in soil associated with a lifetime risk of
cancer of IxlO"4 (pCi/g)
SF = External exposure slope factor for Cs-137 plus its short-lived progeny
Ba-137m for an effective infinite slab (3.7xlO"6 risk/yr per pCi/g,
30-year slope factors are listed in Appendix C)
t = time period of exposure (30 years)
AF1 = unitless adjustment factor to account for the thickness of the
contaminated zone of 5 cm (0.46 for a thickness of 5 cm)
AF2 = unitless adjustment factor to account for terrain roughness and indoor
shielding (0.5)
AF3 = unitless adjustment factor to account for the area of the contaminated
zone (1.0 for most sites and radionuclides since, as long as the
contaminated area exceeds about IxlO4 m2, the area is effectively
infinite).
Based on this equation, the concentration of Cs-137 in soil (C) which corresponds to a risk of
IxlO"4 at Reference Site I is about 3.8 pCi/g, which agrees well with the above cited risk
factor.
Review Draft - 9/26/94 6-17 Do Not Cite or Quote
-------
The key uncertainties in the calculation of the risk factor are the uncertainties in the slope
factor and the first two adjustment factors. There is little uncertainty in the third adjustment
factor since, as indicated in the generic sensitivity analysis presented in Table 3-15, the area
of contamination does not begin to affect the risk factor for Cs-137 until the contaminated
area is less than about 10,000 m2.
As discussed earlier, an external slope factor could range from 0 to as much as 5 times the
assumed value. In addition, if a family were to take occupancy at a location on the site where
the average thickness of the contaminated zone was significantly greater than 5 cm (i.e., the
thickness assumed for Reference Site I) or if they had living habits which kept them outdoors,
all adjustment factors would be 1.0. As a result, the risk factor would increase about 4-fold
and the cleanup concentrations would decrease 4-fold to about 1 pCi/g. Based on Figure 4-4,
the cleanup volume would thereby increase to about IxlO6 m3; i.e., cleanup to close to
background (background concentrations of Cs-137 at a site are due to fallout and are typically
0.7 pCi/g (see Table 7-7).
If the thickness of the contaminated zone were only 1 cm, instead of 5 cm, the risk factor
would decrease about 4-fold and the soil cleanup concentration would increase to about 15
pCi/g (see Figure 6-3, which presents the results of a sensitivity analysis for the thickness of
the contaminated zone for Cs-137). Inspection of Figure 4-4 reveals that at a soil cleanup
concentration of 15 pCi/g, the soil cleanup volume would be about 2xl05 m3.
Based on this overview, and given the contamination distribution, the cleanup volume for
Reference Site I required to achieve a risk level of IxlO"4 could be as high as the entire
volume of contaminated soil (i.e., about l.SxlO6 m3) to 2xl05 m3.
If the cleanup level were set at IxlO"5 or IxlO"6, there would be little option but to remediate
all the contaminated soil down to background because, at these risk levels, there is little
uncertainty that the cleanup concentration would be at or below background.
Because the limiting pathway for Cs-137 is external radiation exposure, uncertainties in
hydrogeology, agricultural practices, and dust suspension factors, which are highly uncertain
for most sites, do not contribute to uncertainties in the risk factor or uncertainties in the
derived soil cleanup volumes.
Review Draft - 9/26/94 6-18 Do Not Cite or Quote
-------
Figure 6-3
Site 1 - Residential Scenario
Total Dose Rate vs. Time
t
_ 1.E+00 1
re
1 LE-01 -
E
re 1.E-02 -
V
V)
0
Q 1.E-03 -
1 F r\A
*&m _ ^^*AA.JT E
^"m ^ ^ ==
• ~^^__^ uontamination
^ ~V ~^~--.^
^^^=^^^= ^**~>^^ =
"^•^NI^^^^
^^-A.^
— "A^-
Depth (cm)
= — 1 — 0.01
• 0.05
= —A— 0.25
N^
]^
0 50 100 150 200
Time (years)
250
Site I - Residential Scenario
Total Dose Rate (mrem/year) vs. Time (years) for Various
Contaminated Zone Thicknesses (meters)
Time
0.01
0.05
0.25
0
1
5
10
20
30
35
40
45
50
60
80
100
150
200
210
220
230
240
245
250
3.06E-01 1.
2.62E-01 1.
1.18E-01 9.
O.OOE+00 7.
5.
4.
2.
9.
4.
0.
23E+00
17E+00
76E-01
67E-01
93E-01
49E-01
34E-01
18E-02
06E-02
OOE+00
2.65E+00
2.59E+00
2.34E+00
2.06E+00
1.60E+00
1.24E+00
1.09E+00
9.62E-01
8.47E-01
7.45E-01
5.76E-01
3.42E-01
2.01E-01
4.93E-02
9.31E-03
6.16E-03
3.82E-03
2.11E-03
8.75E-04
3.99E-04
O.OOE+00
Review Draft - 9/26/94
6-19
Do Not Cite Or Quote
-------
Reference Site II
Reference Site II is based in part on conditions at Fernald. The data characterizing this site is
much more complete than that for Reference Site I, and the uncertainty in the contaminated
soil volume and radionuclide concentrations is relatively small.
A large number of radionuclides are present at Fernald, but the most important radionuclide
from the perspective of soil contamination is U-238. However, Ra-226 may also be important
for the on-site portion of Fernald. Accordingly, insight into the uncertainty in the risk factors
for these radionuclides provides insight into the uncertainty in the Fernald cleanup volumes.
In developing Reference Site II, the Fernald was divided into 7 subsites. Each subsite was
separately analyzed to determine the cleanup volume and then the summed value is reported
in Table 5-3. However, subsites II-6 and II-7 are responsible for the majority of the
contaminated soil volume.
For subsite II-6 (see Figure 4-10), the cleanup volume is determined primarily by Ra-226,
which has a high risk factor of 3.12x10"4 cancers per pCi/g, primarily due to indoor radon and
direct radiation to a lesser degree (see Figure 6-4). For a cleanup level of IxlO"4, the Ra-226
cleanup concentration is 0.32 pCi/g. This is less than the variability in natural background,
and, as a result, cleanup to this risk level would require the entire contaminated volume of soil
on-site at subsite II-6 to be remediated. This is approximately 8.4xl05 m3, which is consistent
with the value in Table 5-3 of 9.36xl05 m3.
Uncertainty in the Ra-226 risk factor is primarily due to uncertainty in the radon
concentration ratio and the risk coefficient for radon. RESRAD derives the indoor radon
concentration through the use of a diffusion model which results in an indoor radon risk factor
of 1.2xlO"4 risk per pCi/g3. A simple and reliable method for checking on the risk factor and
gaining insight into its uncertainties is to use the simple relationship described in Section
2.2.5.5; i.e., 4.62xlO"5 risk of cancer per person per year per pCi/g of Ra-226 in soil, or
1.4xlO"3 lifetime risk per pCi/g. Note that the rule of thumb approach results in a
The lifetime risk from inhalation of radon and radon decay products is calculated as the difference
between the Ra-226 risk factor including the radon pathway and the Ra-226 risk factor excluding the
radon pathway listed in Table 6-2.
Review Draft - 9/26/94 6-20 Do Not Cite or Quote
-------
Figure 6-4
1.E+02
1.E-05
Site II - Residential Scenario
Ra-226 +D Dose Rate vs. Time
50
100 150 200 250 300 350
Time (years)
400 450
500
Site II - Residential Scenario
Ra-226+D Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
10
30
100
300
350
400
450
499
>500 (b)
(a)
(b)
2.
2.
2.
2.
2.
1.
1.
7.
4.
9.
0.
Total
65E+01
64E+01
60E+01
51E+01
21E+01
30E+01
05E+01
57E+00
18E+00
42E-02
OOE+00
Radon
Inhalation Ground
1.59E+01 7.96E+00 1.
1.59E+01 7.96E+00 1.
1.56E+01 7.92E+00 1.
1.49E+01 7.83E+00 1.
1.25E+01 7.49E+00 1.
5.91E+00 5.96E+00 6.
4.35E+00 5.21E+00 4.
2.85E+00 4.12E+00 2.
1.39E+00 2.49E+00 1.
2.73E-02 6.12E-02 2.
0. OOE+00 0. OOE+00 0.
Plant
75E+00
75E+00
71E+00
62E+00
33E+00
05E-01
44E-01
89E-01
41E-01
76E-03
OOE+00
Meat
4.37E-01
4.36E-01
4.29E-01
4.15E-01
3.70E-01
2.56E-01
2.31E-01
1.50E-01
7.33E-02
1.43E-03
0. OOE+00
3
3
3
3
2
1
1
1
5
1
0
Milk
.24E-01
.23E-01
.18E-01
.08E-01
.73E-01
.86E-01
. 67E-01
.08E-01
.29E-02
.03E-03
.OOE+00
8,
8,
8,
8,
8,
7,
7,
4,
2,
4,
0,
Soil
. 88E-02
. 88E-02
. 82E-02
. 72E-02
. 42E-02
. 65E-02
. 47E-02
. 86E-02
. 37E-02
. 64E-04
.OOE+00
Others (a)
i.
i.
i.
i.
i.
9.
9.
6.
2.
5.
0.
10E-02
10E-02
09E-02
08E-02
04E-02
44E-03
22E-03
OOE-03
93E-03
72E-05
OOE+00
"Others" includes the water independent inhalation pathway.
All
the water dependent pathways are
Dose rates
for all pathways are equal
equal to
O.OOE+00.
to 0. OOE+00 for times
between
500 and 10;
,000 years.
Review Draft - 9/26/94
6-21
Do Not Cite Or Quote
-------
radon risk factor approximately 10 times higher than that derived by RESRAD (see Table 6-
2). The reason for the 10-fold difference is the rule of thumb value is based on the
assumption that the thickness of the contaminated zone is at least 5 meters. For II-6, the
thickness of the contaminated zone is assumed to be 0.5 meters. Adjusting for the thickness
of the contaminated zone, the two approaches for deriving the risk factor are compatible.
Imbedded in the simple relationship is the assumption that 1 pCi/g of Ra-226 in soil results in
an average indoor radon concentration of 1.25 pCi/1. Subsequent sections of this report reveal
that the concentration ratio could be many times higher depending on soil properties and
structural characteristics of the residence.
This exercise reveals that the risk factor for Reference Site II for Ra-226 in Table 6-2 could be
more than 10 times higher if the contaminated zone were in fact thicker or if the radon
concentration ratio were higher. In addition, Section 3.2.2 also reveals that the generic risk
factor for Ra-226 could range from 0 to 5 times the generic value. However, such increases
in the risk factor would not necessarily result in an increase in the cleanup volume. For
example, using the current risk factor, all the soil contaminated above background would
require remediation if the cleanup level were set at IxlO"4. Accordingly, a higher risk factor
would not increase the cleanup volume. Similarly, a more restrictive cleanup level would not
result in an increase in the cleanup volume. If the cleanup level were set at IxlO"3, the
cleanup concentration would be 3.2 pCi/g, which still requires virtually all the soil above
background to be remediated. As a general rule, notwithstanding the uncertainties in the risk
factors, if the cleanup for a site containing Ra-226 is set at IxlO'4 to IxlO'3 or less and
includes the potential for the buildup of indoor radon, virtually all of the soil contaminated
above background will need to be remediated.
This conclusion is based on the assumption that indoor radon is the limiting pathway. If
however, the radon issue were resolved (perhaps by installing a sub-slab ventilation system),
the risk factor for Ra-226 would decrease to 1.92xlO"4 (see Table 6-2). This is a relatively
small change and would not significantly change the cleanup volume. The reduction in the
risk factor would have been greater if the thickness of the contaminated zone were 5 as
opposed to 0.5 m. For the direct radiation pathway, an increase in the thickness of the
contaminated zone would not result in an increase in the risk factor because the zone of
influence for direct radiation is only the top 15 to 20 cm. However, an increase in the
thickness of the contaminated zone would result in a significant increase in the radon pathway
contribution to the risk factor because the zone of influence for indoor radon is the top 5
meters of soil.
Review Draft - 9/26/94 6-22 Do Not Cite or Quote
-------
Figure 6-5
1.E-01
1.E-05
Site 11-7 - Residential Scenario
Total Dose Rate vs. Time
10 15 20 25 30
Time (years)
35
40
45
-Total
-U-238
Ground
-U-234
Inhalatio
n(a)
-U-238
Inhalatio
n
(a)
50
Site 11-7 - Residential Scenario
Total Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
30
40
45
49
>50 (c)
(a)
(b)
(c)
Total
8.87E-02
8.70E-02
8.02E-02
7.16E-02
5.44E-02
3.68E-02
1.87E-02
9.44E-03
1.90E-03
O.OOE+00
U-238
Ground
3.01E-02
2.96E-02
2.75E-02
2.49E-02
1.93E-02
1.33E-02
6.87E-03
3.50E-03
7.10E-04
O.OOE+00
U-234
Inhalation
(a)
1.64E-02
1.61E-02
1.46E-02
1.28E-02
9.39E-03
6.11E-03
2.98E-03
1.47E-03
2.91E-04
O.OOE+00
U-238
Inhalation
(a)
1.52E-02
1.48E-02
1.35E-02
1.18E-02
8.66E-03
5.63E-03
2.75E-03
1.36E-03
2.69E-04
O.OOE+00
U-235
Ground
i.
i.
i.
i.
9,
7,
3,
1.
4,
0,
. 46E-02
.44E-02
.36E-02
.24E-02
. 94E-03
. 09E-03
. 81E-03
. 98E-03
. 07E-04
. OOE+00
Water independent inhalation pathway excludes radon
"Others" includes all
Dose rates
Dose rates
other pathways calculated
for all water dependent pathways
U-234
Milk
2.51E-03
2.45E-03
2.23E-03
1.96E-03
1.43E-03
9.32E-04
4.54E-04
2.24E-04
4.44E-05
O.OOE+00
inhalation.
U-238
Milk Others (b)
2
2
2
1
1
8
4
2
4
0
.41E-03
.36E-03
. 15E-03
.88E-03
.38E-03
.96E-04
.37E-04
.16E-04
.27E-05
.OOE+00
7.
7.
6.
5.
4.
2.
1.
6.
1.
0.
, 42E-03
,26E-03
, 62E-03
,84E-03
.31E-03
, 83E-03
, 40E-03
, 96E-04
,39E-04
, OOE+00
by RESRAD.
are equal
to O.OOE+00
for all pathways are equal to O.OOE+00 for times between
50 and 10
,000 years.
Review Draft - 9/26/94
6-23
Do Not Cite Or Quote
-------
Figure 6-6
1.E-01 -,
1.E-05
Site 11-7 - Residential Scenario
U-238 Dose Rate vs. Time
10 15 20 25 30 35 40 45 50
Site II-7 - Residential Scenario
U-238 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
30
40
45
49
>50 (c)
(a)
(b)
(c)
5.
4.
4.
4.
3.
2.
1.
5.
1.
0.
Total
06E-02
96E-02
57E-02
08E-02
10E-02
09E-02
06E-02
33E-03
07E-03
OOE+00
Inhalation
Ground (a) Milk
3.01E-02 1.52E-02 2.41E-03 1
2.96E-02 1.48E-02 2.36E-03 9
2.75E-02 1.35E-02 2.15E-03 8
2.49E-02 1.18E-02 1.88E-03 7
1.93E-02 8.66E-03 1.38E-03 5
1.33E-02 5.63E-03 8.96E-04 3
6.87E-03 2.75E-03 4.37E-04 1
3.50E-03 1.36E-03 2.16E-04 9
7.10E-04 2.69E-04 4.27E-05 1
0. OOE+00 0. OOE+00 0. OOE+00 0
Plant
.01E-03
.87E-04
.97E-04
.88E-04
.76E-04
.75E-04
.83E-04
.03E-05
.79E-05
.OOE+00
Water independent inhalation pathway excludes radon
"Others" includes the following pathways:
all
the water dependent pathways (water,
Dose rates
for all pathways are equal to 0
9.
9.
8.
7.
5.
3.
1.
8.
1.
0.
Soil
49E-04
28E-04
44E-04
41E-04
42E-04
52E-04
72E-04
49E-05
68E-05
OOE+00
Meat Others (b)
9
9
8
7
5
3
1
8
1
0
.47E-04
.25E-04
.41E-04
.39E-04
.41E-04
.52E-04
.72E-04
.47E-05
.68E-05
.OOE+00
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
inhalation.
Radon (water independent and dependent), and
fish,
plant, meat,
and milk).
.OOE+00 for times between
50 and 10
,000 years.
Review Draft - 9/26/94
6-24
Do Not Cite Or Quote
-------
Subsite II-7 represents a different problem than subsites II-l or II-6 because the risks are
entirely due to uranium (see Figure 4-11). Two radionuclides contribute to most of the risk,
U-238, with a risk factor of 8.32xlO'7 and U-234, with a risk factor of 1.27X10'7. Figures 6-5
and 6-6 present the total dose rate as a function of time for each radionuclide and pathway.
As indicated, external exposure to U-238 is the limiting radionuclide and pathway.
U-238 is one of the more complex radioisotopes from the perspective of assessing the
uncertainties in the risk factor. Unlike most radionuclides, which have only one or two
important pathways, U-238 can contribute to risk from the direct radiation, dust inhalation,
groundwater, and crop ingestion pathway. The relative importance of each pathway depends
on site-specific characteristics. The primary reason for this complexity is uranium can have a
relatively low Kd and therefore reach an aquifer within the time period of interest. It's short-
lived daughters also have a significant gamma which creates the potential for external
exposure, and its alpha emission represent a significant inhalation risk. Figure 6-6 indicates
that the limiting pathways in this case are direct external radiation and inhalation of
suspended dust because the U-238 cannot reach the aquifer within the 1000 year time period
of interest.
An important consideration in the uncertainty analysis of U-238 at any site is the possibility
that the U-238 could reach the groundwater within the time period of interest. If so, the
groundwater pathway dominates (see Table 3-1). At Reference Site II, the depth to the
aquifer is chosen to be about 10 meters, the infiltration rate is 0.3 m/yr, the effective porosity
is 0.2, and the Kd for uranium is 1600 (see Tables 4-6, 4-7, and 4-8). These parameters can be
used to estimate the approximate travel time (T) to the aquifer, as follows:
T = D x R/v
where:
D = Thickness of the unsaturated zone (10 m)
R = Retardation factor (approximated as 5 times Kd or 8000)
v = Velocity at which rainwater percolates down through the unsaturated
zone (approximated as the infiltration rate/volumetric water content, or
about 1 m/yr)
Review Draft - 9/26/94 6-25 Do Not Cite or Quote
-------
Therefore:
T = 10x8000/1 = 80,000 years
Clearly, the uranium cannot reach the aquifer within a 1000 year time period of interest unless
the hydrogeological characteristics are completely mischaracterized. For example, if
the Kd were 10 times smaller due to the presence of chelating agents or if the infiltration
velocity were 10 times greater due to channeling, or if there were locations at the site where
the thickness of the unsaturated zone were 1 instead of 10 meters, the travel time could be
reduced to 8000 years. Accordingly, contamination of the groundwater pathway offsite at
Reference Site II, as modeled, due to leachate from uranium contaminated soil would appear
to be unlikely. However, for the purpose of this uncertainly analysis, the possibility of
facilitated transport is addressed.4
Figure 6-7, with its accompanying table, indicates how the results of the analysis would
change if low Kd values were used which resulted in the arrival of the uranium in the aquifer
within the 1000 year period of interest. Note that, initially, the water independent pathways
(i.e., external radiation from the ground) is the limiting pathway. However, the water
independent pathways decline rapidly with time because the low Kd results in rapid depletion
of the contaminated soil. At approximately year 50, the water dependent pathways begin to
contribute to the risk because it is at this time that the uranium reaches the aquifer. The water
dependent doses increase rapidly and eventually deliver a dose rate more than 10 times the
original water independent pathways dose rates. After the groundwater pulse moves through
the system, the dose rates decline rapidly and then level off or slightly increase with time due
to the ingrowth of Th-230 and Ra-226 from the decaying U-234.
If the groundwater travel time were less than 1000 years, the maximum concentration of
uranium in the groundwater would be the ratio of the concentration in the soil to the uranium
Kd. Therefore, the upper bound risk factor for uranium via the groundwater pathway could be
approximated as follows:
Risk per pCi/g = (C/Kd) x 1000 ml/L x 2 L/d x 365 d/yr x 30 yr x SF
(groundwater)
The groundwater at Fernald is contaminated. The method by which this contamination is occurring is
under investigation.
Review Draft - 9/26/94 6-26 Do Not Cite or Quote
-------
Where:
Risk per pCi/g
(groundwater)
C
Kd
SF
radionuclide concentration in soil (1 pCi/g)
uranium distribution coefficient (1600 ml/g)
30 year slope factor for uranium ingestion (l.lxlO"10
lifetime risk of cancer per pCi ingested)
If the groundwater pathway was eliminated due to travel time, the important pathways would
include direct radiation, dust inhalation, and vegetable ingestion. The following presents a
simple method for approximating the risk factors for each of these pathways:
Risk per pCi/g
(external)
1 pCi/g x SF (risk/yr per pCi/g) x AF1 x AF2 x AF3 x t (yrs)
Where:
SF
AF1
AF2 =
AF3 =
Risk per pCi/g
(external)
Review Draft - 9/26/94
30 year external slope factor for uranium+D (1.01x10 )
Adjustment factor for thickness of the contaminated zone (the
contaminated zone indicated in Table 4-6 is 5 cm, which has an
adjustment factor of about 0.5; see Section 3.2 for a discussion
of the effect of contaminated zone thickness on the external dose
conversion factor)
Adjustment factor to account for surface roughness and indoor
shielding (about 0.5). Oakley (Oak 72) estimates that the indoor
dose rate for frame dwellings is about 70 to 80 percent of that
outdoors. Kocher (Koc 83) presents a discussion of correction
factors for external exposure, indicating that structural shielding
can range from 0.7 for automobiles to 0.005 for basements of
large, multistory buildings. Kocher further cites studies for
ground surface roughness correction factors that can range from
1 for paved areas to 0.5 for deeply plowed fields.
Adjustment factor to account for area of the contaminated zone
(assumed to be 1.0 since it is unlikely that the contaminated area
is less than 1000 m2)
exposure duration (30 years)
7.6xlQ-7
6-27
Do Not Cite or Quote
-------
Figure 6-7
1E+01 -i
1 E+00 -
1E-01 -
<
_ 1 E-02 -
1
| 1 E-03
k.
re 1 E-04 -
V
U)
0
Q 1 E-05
1 E-06
1 E-07 -
1 F nft
1
Site 11-7 - Residential Scenario
Distribution Coefficients (Kds) Set to Low Values for
U-234. U-235, U-238, and all Progeny
i< =
^
*
* =
M
^
\
t
*
J
r
/
~^^^^^^=^^^^^^=
*
\ /
x
^. '
>/
\
1
1
1
1 '
1 I
, 1
* • =
J^^^=^*^^^"=^^*^B=^^^^=^^
wm f 4
• Total
1
— • Water
Independent
— —Water
Dependent
10 100 1,000 10,000
Time (years)
-------
Figure 6-7 (continued)
Site 11-7 - Residential Scenario
Distribution Coefficients (Kds) Set to Low Values for U-234, U-235, U-238, and all Progeny
Water Independent Pathway Major Contributors
Water Dependent Pathway Major Contributors
Time
0
1
5
10
20
40
47
60
80
100
110
120
130
140
145
150
155
160
170
180
190
200
250
300
700
1,000
3,000
10,000
Total
8.9E-02
4.1E-02
1.9E-03
4.0E-05
3.7E-07
1.2E-07
3.7E-08
2.2E-04
1.7E-03
5.1E-03
8.1E-03
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
3.8E-03
7.1E-04
8.0E-04
9.7E-04
9.7E-04
l.OE-03
1.1E-03
1.3E-03
2.1E-03
U-238
Ground
3.0E-02
1.4E-02
6.5E-04
1.4E-05
5.8E-09
3.5E-14
1.2E-14
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-234
Inhal.
1.6E-02
7.6E-03
3.4E-04
7.4E-06
2.9E-07
9.2E-08
2.9E-08
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-238
Inhal.
1.5E-02
7.0E-03
3.2E-04
6.5E-06
2.6E-09
3.5E-13
1.1E-13
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-235
Ground
1.5E-02
6.8E-03
3.2E-04
6.8E-06
3.0E-09
3.5E-16
7.1E-19
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-234
Food
4.5E-03
2.1E-03
9.5E-05
2.0E-06
1.2E-08
3.7E-09
1.2E-09
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Independen U-234
t Water
8.9E-02
4.1E-02
1.9E-03
4.0E-05
3.7E-07
1.1E-07
3.7E-08
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7.7E-01
7.7E-01
7.7E-01
7.8E-01
7.9E-01
7.7E-01
7.7E-01
7.7E-01
1.8E-03
3.5E-04
4.0E-04
4.8E-04
4.8E-04
5.1E-04
5.3E-04
6.5E-04
l.OE-03
U-238
Water
0
0
0
0
0
0
0
0
0
0
0
7.4E-01
7.4E-01
7.4E-01
7.5E-01
7.6E-01
7.4E-01
7.4E-01
7.5E-01
1.4E-03
7.3E-07
5.1E-08
7.1E-08
7.4E-08
6.1E-08
7.0E-08
1.2E-07
4.0E-07
U-234
Food
0
0
0
0
0
0
0
0
0
0
0
6.8E-02
6.8E-02
6.8E-02
6.8E-02
6.9E-02
6.8E-02
6.8E-02
6.8E-02
4.2E-04
3.4E-04
3.8E-04
4.6E-04
4.6E-04
4.9E-04
5.1E-04
6.3E-04
l.OE-03
U-238
Food
0
0
0
0
0
0
0
0
0
0
0
6.5E-02
6.5E-02
6.5E-02
6.6E-02
6.6E-02
6.5E-02
6.5E-02
6.5E-02
1.2E-04
1.2E-07
4.7E-08
6.7E-08
7.0E-08
5.8E-08
6.6E-08
1.2E-07
3.8E-07
U-235
Water
0
0
0
0
0
0
1.3E-08
2.0E-04
1.6E-03
4.7E-03
7.5E-03
4.9E-02
5.0E-02
5.0E-02
5.0E-02
5.0E-02
4.8E-02
4.7E-02
4.4E-02
8.3E-05
4.0E-08
1.7E-11
0
0
0
0
0
0
Water
Dependent
0
0
0
0
0
0
1.4E-08
2.2E-04
1.7E-03
5.1E-03
8.1E-03
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
1.7E+00
3.8E-03
7.1E-04
8.0E-04
9.7E-04
9.7E-04
l.OE-03
1.1E-03
1.3E-03
2.1E-03
-------
If the contaminated zone thickness were greater than 15 cm and the individuals were assumed
to spend all their time outdoors, the risk factor for external exposure would increase to about
3xlQ-6.
For the dust inhalation pathway, the risk factor is approximated as follows:
Risk per pCi/g (dust) =
1 pCi/g x 200 //g/m3 x IxlO'6 g///g x 8000 m3/yr x 30 yr x SF x
AF1 x AF2x AF3
Where:
200 =
8000
SF
AF1
airborne dust loading (//g/m3). This is the recommended default
value cited in RESRAD (ANL 93b). The supporting
documentation for RESRAD indicates that this is a generally
high end value, especially as applied to long term exposures in
non urban settings.
annual breathing rate (m3/yr)
30 year inhalation slope factor (1.87xlO"8 risk/pCi inhaled)
Adjustment factor to account for thickness of the contaminated
zone. Since the thickness of the contaminated zone is 5 cm, an
adjustment factor of 0.33 is applied to account for the
assumption that it is the average concentration in the top 15 cm
that is responsible for the airborne dust loading.
Adjustment factor to account for indoor occupancy and the
indoor/outdoor decontamination factor (assumed to be about 0.5,
see discussion in Section 3.2)
Adjustment factor to account for area of the contaminated zone
(for areas greater than IxlO4 m2, the value is 1.0; this means that
virtually all of the airborne dust at the occupied location is
assumed to be from contaminated soil
Risk per pCi/g (dust) = l.SxlO'7
If the thickness of the contaminated zone were greater than 15 cm and if most of the time
were spent outdoors, this risk factor could increase to about IxlO"6. However, if a less
conservative dust loading were assumed, such as 10 //g/m3, the risk factor would decrease 20
foldto7.5xlQ-9.
AF2 =
AF3 =
Review Draft - 9/26/94
6-30
Do Not Cite or Quote
-------
For the crop ingestion pathway, the risk factor is estimated as follows:
Risk per pCi/g (crop) = 1 pCi/g x Bv x I (kg/yr) x 1000 g/kg x 30 yr x SF
Where:
Bv = soil to plant transfer factor for uranium (2.5xlO"3, see Table C.3).
EPA 89 indicates that the range of the average Bvs for uranium
in vegetables is 1.4xlO"3 to 0.2.
I = ingestion rate of vegetable (122.5 + 13.3 kg/yr from Table 3-11).
SF = 30 year ingestion slope factor (l.lOxlO"10)
Risk per pCi/g = l.lxlO'6
(crops)
The uncertainty in this value depends primarily on the uncertainty in Bv, I, and SF. The Bv
could be a factor of 100 higher to about 2 lower. SF could range from 0 to 10 times higher
than the selected value. The ingestion rate of contaminated crops could not reasonably be
higher since it assumes a large portion of the persons vegetables are grown in contaminated
soil over a 30 year period.
In summary, the risk factors for uranium for Reference Site II by pathway are approximated
as follows:
Pathway Risk Factor
Groundwater = l.SxlO"6
Direct Radiation = 7.6xlO"7
Dust Inhalation = l.SxlO'7
Crop Ingestion = l.lxlO"6
Total (all paths) = S.SxlO'6
Total = 2.0xlQ-6
(without groundwater)
The risk factor derived by RESRAD for U-238 without decay products is 8.95xlO"7 (see Table
6-3), which is consistent with the above hand calculation, especially since the groundwater is
Review Draft - 9/26/94 6-3 1 Do Not Cite or Quote
-------
not assumed to be a contributor at subsite 11-2. These hand calculated approximations are
reliable within a factor of approximately 2 due to differences in the adjustment factors.
At a cleanup level of IxlO"4, a risk factor of 8.32xlO"7 translates to a cleanup concentration of
120 pCi/g. Applying this risk factor to Figure 4-11, no soil would require remediation
because no soil is contaminated above 120 pCi/g. If groundwater is assumed to be present,
the risk factor would increase to about 3.5x10"6, with an associated IxlO"4 cleanup
concentration of about 30 pCi/g. Given the Kd of 1600, it is unlikely that the cleanup
concentration could be much lower because it is based on the assumption that the leachate is
undiluted. However, as indicated in Section 3, the Kd could be 10 to 100 times smaller,
resulting in a groundwater risk factor 10 to 100 times greater and cleanup concentrations
down to background levels. Alternatively, if less conservative assumptions regarding Bv, I,
and airborne dust loading are used, these pathways could be virtually eliminated, leaving only
the direct radiation pathway, which by itself is associated with a cleanup concentration at
IxlO"4 risk of 130 pCi/g. Clearly, the uncertainties are large and significant. Depending on
the assumptions, all of which are plausible, one could conclude that either all or very little of
the contaminated soil at Reference Site II requires remediation in order to achieve cleanup
levels on the order of IxlO"4.
Reference Site III
Reference Site III is based in part on INEL and, like Reference Site I, it is assumed that the
soil contamination is dominated by Cs-137 and the thickness of the contaminated zone is 5
cm. As a result, the discussion pertaining to Reference Site I also applies to Reference Site
III.
Applying a cleanup concentration of 3.8 pCi/g to Figure 4-12 results in an estimated cleanup
volume of 4xl05 m3 in order to achieve a risk level of IxlO"4. This is consistent with the
mathematically interpolated value of 4.63xl05 m3 presented in Table 5-3.
As a rule, at sites contaminated with strong gamma emitters, such as Cs-137, Co-60, and Ra-
228, the direct radiation pathways is the major contributor to the risk factor, and the primary
assumption that contributes to the uncertainty in the risk factor is the thickness of the
contaminated zone. For contaminated zone thicknesses less than about 15 cm, the risk factor
is highly sensitive to the assumed thickness. Above 15 cm, the risk factor is insensitive to
Review Draft - 9/26/94 6-32 Do Not Cite or Quote
-------
thickness. All other site parameters are essentially irrelevant in deriving the risk factors for
these radionuclides.
Reference Site IV
Reference Site IV is based in part on Weldon Spring. Two radionuclides contribute to the
risk,
U-238, with a risk factor of 1.41X10'6, and U-234, with a risk factor of 2.74xlO'7 (see Table 6-
2). U-238 is limiting, and, since the two radionuclides can be assumed to be commingled, it
is only necessary to discuss U-238.
At a cleanup level of 1x10"4, the cleanup concentration is about 70 pCi/g. Inspection of
Figure 4-13 reveals that the cleanup volume at 70 pCi/g is about 3xl04 m3. This is consistent
with the mathematically extrapolated value of 3.71xl04 m3 presented in Table 5-3. At a
cleanup level of 1x10"5, the cleanup concentration would be 7 pCi/g, which, according to
Figure 4-13, corresponds to about 8xl04 m3. Table 5-3 indicates a cleanup volume of
9.73xl04. These comparisons help to demonstrate how the cleanup volumes were derived and
begin to provide insight into the reliability and uncertainty in the numbers.
Figure 6-8 indicates that U-238 exposure from direct radiation is limiting, with significant
contributions from dust inhalation. Like Reference Site II, the uncertainties in the risk factors
for U-238 are substantial and significant. Figure 6-9 and its accompanying table reveal how
the results would change if a low Kd were assumed for uranium. As for Reference Site II, the
groundwater pathway dominates the dose rate
following its transport to the aquifer. This situation rarely occurs because the uranium is held
up in the unsaturated zone for periods of time substantially greater than 1000 years.
Reference Site V
Reference Site V is based in part on Savannah River and, like Reference Sites I and II, it is
assumed that the soil contamination issues are dominated by Cs-137. Figure 6-10, which
presents the dose rate by pathway and as a function of time, reveals that the direct radiation
exposure is the dominant pathway. As a result, the discussion pertaining to Reference Site I
also applies to Reference Site V.
Applying a cleanup concentration of 3.8 pCi/g to Figure 4-14 yields a cleanup volume of
about 6xl06 m3, which is consistent with the mathematically interpolated value of 6.02xl06 m3
in Table 5-3.
Review Draft - 9/26/94 6-33 Do Not Cite or Quote
-------
Figure 6-8
1.E+00
I
0)
VI
o
Q
Site IV - Residential Scenario
Total Dose Rate vs. Time
40
60
Time (years)
80
100
—•—Total
—I—U-238
Ground
—A—U-234
Inhal. (a)
—*— U-238
Inhal. (a)
—e—U-235
Ground
—H— U-234
Milk
—A—U-238
Milk
120
Site IV - Residential Scenario
Total Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
40
60
80
100
108
>108(c)
(a)
(b)
(c)
Total
1.63E-01
1.61E-01
1.51E-01
1.40E-01
1.20E-01
8.39E-02
5.42E-02
2.91E-02
7.75E-03
9.42E-07
O.OOE+00
U-238
Ground
4.82E-02
4.76E-02
4.53E-02
4.25E-02
3.72E-02
2.73E-02
1.85E-02
1.03E-02
2.86E-03
3.51E-07
O.OOE+00
U-234
Inhal. (a)
3.54E-02
3.48E-02
3.25E-02
2.98E-02
2.48E-02
1.64E-02
9.94E-03
4.98E-03
1.22E-03
1.43E-07
O.OOE+00
U-238
Inhal. (a)
3.27E-02
3.21E-02
3.00E-02
2.75E-02
2.28E-02
1.51E-02
9.17E-03
4.59E-03
1.12E-03
1.32E-07
O.OOE+00
U-235
Ground
2.04E-02
2.02E-02
1.94E-02
1.84E-02
1.64E-02
1.27E-02
9.02E-03
5.39E-03
1.60E-03
2.03E-07
O.OOE+00
Water independent inhalation pathways exclude radon
"Others" includes all
Dose rates
Dose rates
5
5
4
4
3
2
1
7
1
2
0
U-234
Milk
.42E-03
.33E-03
.97E-03
.56E-03
.79E-03
.51E-03
.52E-03
.61E-04
.87E-04
.19E-08
.OOE+00
5
5
4
4
3
2
1
7
1
2
0
U-238
Milk
.21E-03
.12E-03
.78E-03
.38E-03
.64E-03
.42E-03
.46E-03
.32E-04
.79E-04
.10E-08
.OOE+00
Others (b)
i
i
i
i
i
7
4
2
5
7
0
.57E-02
.54E-02
.44E-02
.32E-02
. 11E-02
.44E-03
.58E-03
.35E-03
.91E-04
.01E-08
.OOE+00
inhalation.
other pathways calculated by RESRAD.
for all water dependent pathways
are equal
to
O.OOE+00
for all pathways are equal to O.OOE+00 for times between
108 and
10
,000 year
Review Draft - 9/26/94
6-34
Do Not Cite Or Quote
-------
Figure 6-9
1 E+02 -i
1E+01 -
1 E+00 -
1E-01 «
re
V
| 1 E-02 -
E
a
| 1E-03-
0)
V)
Q 1E-04-
1 E-05 -
1 E-06 -
1 F ny
1
Site IV - Residential Scenario
Distribution Coefficients (Kds) Set to Low Values for
U-234, U-235, 1^-238, and all Progeny
^* _
s
V '^
\ T A
\_ _
\ *
x .
1
\ 1
• -•_J
7^ ^
^_
^E
1 1
_ 1
\\ =
* i j
m i
r 1
i
i
• Total
Total
^~ ™~ Water Dep.
1 Total
10 100 1,000 10,000
Time (years)
-------
Figure 6-9 (continued)
Site IV - Residential Scenario
Distribution Coefficients (Kds) Set to Low Values for U-234, U-235, U-238, and all Progeny
Water Independent Pathway Major Contributors
Water Dependent Pathway Major Contributors
Time
0
1
5
10
20
30
40
50
52
60
80
100
108
110
120
125
130
131
135
140
150
160
180
200
300
700
1,000
3,000
10,000
1.
1.
1.
1.
1.
1.
1.
1.
9,
4,
3,
1.
1.
1.
2,
1.
1.
1.
1.
2,
2,
7,
1.
1.
1.
1.
1.
1.
1.
Total
U-238
Ground
. 6E-01 4.8E-02
.OE-01 3.0E-02
.4E-02 4.2E-03
.2E-03 3.7E-04
.OE-05 2.8E-06
.5E-06 2.0E-08
.2E-06 1.5E-10
.OE-06 1.6E-12
.8E-07 8.4E-13
. 6E-04 4.7E-13
. 6E-03 2.9E-13
.1E-02 9.3E-14
.5E-02 1.2E-17
. 6E-02 0
.4E-02 0
.3E+01
. 9E+01
. 9E+01
. 9E+01
.2E-01
. 1E-03
.1E-04
. 1E-03
.1E-03
. 1E-03
.1E-03
. 1E-03
. 1E-03
. 1E-03
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-234
Inhal.
3.5E-02
2.2E-02
3.0E-03
2.6E-04
3.1E-06
1.2E-06
9.9E-07
8.4E-07
8.0E-07
6.9E-07
4.0E-07
1.1E-07
1.4E-11
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-238
Inhal.
3.3E-02
2.0E-02
2.8E-03
2.4E-04
1.7E-06
1.2E-08
8.9E-11
5.5E-12
4.9E-12
4.0E-12
2.3E-12
6.5E-13
8.1E-17
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-235
Ground
2.0E-02
1.3E-02
1.8E-03
1.6E-04
1.2E-06
9.2E-09
6.9E-11
5.1E-13
1.6E-13
3.7E-15
1.6E-19
3.5E-24
l.OE-29
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
U-234
Food
9.8E-03
6.0E-03
8.4E-04
7.1E-05
5.6E-07
5.1E-08
4.1E-08
3.5E-08
3.3E-08
2.9E-08
1.6E-08
4.6E-09
5.7E-13
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Water Ind
Total
1.6E-01
1. OE-01
1.4E-02
1.2E-03
1. OE-05
1.5E-06
1.2E-06
1. OE-06
9.8E-07
8.4E-07
4.9E-07
1.4E-07
1.7E-11
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
8
8
1
1
4
6
6
6
6
6
6
6
U-234
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.1E+00
.8E+00
.9E+00
.OE-01
.OE-03
.3E-04
. 6E-04
.7E-04
. 6E-04
. 6E-04
.7E-04
.7E-04
.7E-04
U-238
Water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5.8E+00
8.5E+00
8.5E+00
9.7E-02
7.0E-04
5.1E-06
l.OE-07
2.0E-07
7.4E-08
1.4E-07
6.3E-08
6.7E-08
1.5E-07
U-234
Food
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4.4E-01
6.4E-01
6.4E-01
7.4E-03
2.2E-04
2.5E-04
3.9E-04
3.9E-04
3.9E-04
3.8E-04
3.9E-04
3.9E-04
4.0E-04
U-238
'Food
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4.2E-01
6.1E-01
6.2E-01
7. OE-03
5.1E-05
4.1E-07
5.9E-08
1.2E-07
4.2E-08
7.9E-08
3.5E-08
3.8E-08
8.8E-08
2
4
3
1
1
1
2
3
4
4
4
5
4
2
1
6
U-235
Water
0
0
0
0
0
0
0
0
.9E-09
.3E-04
.4E-03
.OE-02
.4E-02
.5E-02
.3E-02
.5E-01
.9E-01
.9E-01
.9E-01
. 6E-03
.IE-OS
.9E-07
.4E-11
.2E-16
0
0
0
0
0
Water Dep.
Total
0
0
0
0
0
0
0
0
3.0E-09
4.6E-04
3.6E-03
1.1E-02
1.5E-02
1.6E-02
2.4E-02
1.3E+01
1.9E+01
1.9E+01
1.9E+01
2.2E-01
2.1E-03
7.1E-04
1.1E-03
1.1E-03
1.1E-03
1.1E-03
1.1E-03
1.1E-03
1.1E-03
-------
Figure 6-10
1.E+01 -T
&
50 (c)
(a)
(b)
(c)
Inhalation
i.
i.
9.
7.
5.
4.
3.
2.
8.
3.
6.
0.
Total
23E+00
17E+00
72E-01
60E-01
85E-01
42E-01
24E-01
28E-01
87E-02
91E-02
73E-07
OOE+00
Ground
1.18E+00
1.13E+00
9.38E-01
7.34E-01
5.66E-01
4.27E-01
3.14E-01
2.21E-01
8.61E-02
3.80E-02
6.54E-07
0. OOE+00
Meat Milk
3.01E-02 1.07E-02 3
2.86E-02 1.01E-02 3
2.32E-02 8.21E-03 2
1.77E-02 6.25E-03 1
1.32E-02 4.68E-03 1
9.71E-03 3.44E-03 1
6.93E-03 2.45E-03 7
4.75E-03 1.68E-03 4
1.74E-03 6.16E-04 1
7.46E-04 2.64E-04 7
1.25E-08 4.41E-09 1
0. OOE+00 0. OOE+00 0
Plant
.16E-03
.OOE-03
.43E-03
.85E-03
.39E-03
.02E-03
.27E-04
.98E-04
.83E-04
.82E-05
.31E-09
.OOE+00
Water independent inhalation pathway excludes radon
"Others" includes the
all
i.
i.
i.
i.
8.
6.
4.
3.
1.
4.
7.
0.
Soil
90E-04
80E-04
46E-04
11E-04
35E-05
13E-05
37E-05
OOE-05
10E-05
70E-06
86E-11
OOE+00
(a) Others (b)
4
3
3
2
1
1
9
6
2
1
1
0
.05E-06
.84E-06
.12E-06
.37E-06
.78E-06
.31E-06
.32E-07
.38E-07
.34E-07
.OOE-07
.68E-12
.OOE+00
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
inhalation.
following pathways: Radon (water independent and dependent), and
the water dependent pathways (water, fish,
Dose rates
plant, meat,
and milk).
for all pathways are equal to 0. OOE+00 for times between
50 and 10
,000 years.
Review Draft - 9/26/94
6-37
Do Not Cite Or Quote
-------
Reference Site VI
Reference Site VI is based in part on Oak Ridge where the radionuclides which were selected
as dominant from the perspective of soil cleanup are Cs-137 and U-238. Figures 6-11 and 6-
12 indicate the dose rate as a function of time for the various isotopes and pathways. As
indicated, Cs-137 via the direct radiation pathway dominates. The previous discussions
provide insight into the uncertainties and sensitivities associated with their risk factors.
However, it is instructive to examine how the two radionuclides together influence the
cleanup volume.
The Cs-137 risk factor is 2.66xlO"5 (i.e., the same as that used for Reference Sites I and III,
primarily because in all cases the thickness of the contaminated zone was assumed to be 5
cm). Accordingly, if the cleanup level is set at IxlO"4, the soil cleanup concentration for
Cs-137 is 3.8 pCi/g. However, for U-238, the risk factor is 8.32xlO"7, which corresponds to a
cleanup concentration of 120 pCi/g. Assuming the two radionuclides are commingled, and
using Figure 4-15, the cleanup volume obtained for Cs-137 at a cleanup concentration of 3.8
pCi/g is about 2.6xl05 m3. For U-238, the cleanup volume for a cleanup concentration of 120
pCi/g is about IxlO5 m3. Accordingly, Cs-137 dominates. Inspection of Table 5-3 reveals
that the mathematically derived cleanup volume, which is based on curve fitting and
consideration of the contribution of all radionuclides, is 2.36xl05 m3.
This type of discussion is useful in gaining confidence in the computerized methods used to
estimate cleanup volumes. It also reveals that, at least in this case, though several
radionuclides are present, the cleanup volume is dominated by one radionuclide, Cs-137, and
the uncertainties in the cleanup volume are due primarily to uncertainties in the Cs-137
contamination pattern, volume, and risk factor.
Reference Site VII
Reference Site VII is based in part on the Nevada Test Site (NTS). As indicated in Figure 4-
15, three radionuclides are primarily of concern, Pu-239, Am-241 and Cs-137. Figures 6-13
and 6-14 show that Cs-137 is the limiting radionuclide via the external exposure pathway.
Figures 6-15 and 6-16 show the contribution of Pu-239 and Am-241 to the dose rate to
the RME individual.
Review Draft - 9/26/94 6-3 8 Do Not Cite or Quote
-------
Figure 6-11
1.E+01 -T
1.E+00
_ 1
I
VI
o
Q
1
1.E-08 -
1.E-09
Site VI - Residential Scenario
Cs-137 Dose Rate vs. Time
-Total
-Ground
-Meat
-Milk
-Plant
-Soil
-Inhalatio
n
10
15
20 25 30
Time (years)
35
40
45
50
Site VI - Residential Scenario
Cs-137 Dose Rate (mrem/years) vs. Time
Water Independent Pathways (Inhalation Excludes Radon)
Time
(years)
0
1
5
10
15
20
25
30
35
40
45
50
>50 (b)
(a)
(b)
i.
i.
i.
8.
6.
5.
3.
2.
1.
1.
5.
9.
0.
Total
23E+00
18E+00
01E+00
22E-01
58E-01
16E-01
93E-01
88E-01
98E-01
21E-01
54E-02
92E-07
OOE+00
Ground
1.18E+00
1.14E+00
9.75E-01
7.94E-01
6.36E-01
4.99E-01
3.81E-01
2.79E-01
1.92E-01
1.18E-01
5.39E-02
9.65E-07
O.OOE+00
"Others" includes the
all
Meat
3.01E-02
2.88E-02
2.41E-02
1.91E-02
1.49E-02
1.13E-02
8.42E-03
5.99E-03
4. OOE-03
2.38E-03
1.06E-03
1.84E-08
O.OOE+00
Milk
1.07E-02
1.02E-02
8.53E-03
6.75E-03
5.26E-03
4.02E-03
2.98E-03
2.12E-03
1.42E-03
8.41E-04
3.74E-04
6.50E-09
O.OOE+00
Plant
3.16E-03
3.02E-03
2.53E-03
2. OOE-03
1.56E-03
1.19E-03
8.82E-04
6.28E-04
4.20E-04
2.49E-04
1.11E-04
1.93E-09
O.OOE+00
i
i
i
i
9
7
5
3
2
1
6
1
0
Soil
.90E-04
.82E-04
.52E-04
.20E-04
.38E-05
.15E-05
.31E-05
.78E-05
.52E-05
.50E-05
. 67E-06
.16E-10
.OOE+00
Inhalation Others (a)
4
3
3
2
2
1
1
8
5
3
1
2
0
.04E-06
.87E-06
.24E-06
.56E-06
.OOE-06
.52E-06
. 13E-06
.06E-07
.38E-07
. 19E-07
.42E-07
. 47E-12
.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
O.OOE+00
following pathways: Radon (water independent and dependent), and
the water dependent pathways
Dose rates
(water, fish
, plant, meat
, and milk).
for all pathways are equal to O.OOE+00 for times between
50 and 10
,000 years.
Review Draft - 9/26/94
6-39
Do Not Cite Or Quote
-------
Figure 6-12
1.E-01
1.E-06
Site VI - Residential Scenario
Total Dose Rate vs. Time
15
20 25 30
Time (years)
35
40
45
—•—Total
—I—U-238
Ground
—A—U-234
Inhal. (a)
—*— U-238
Inhal. (a)
—e—U-235
Ground
—H— U-234
Milk
—A—U-238
Milk
50
Site VI - Residential Scenario
Total Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
15
20
30
40
45
50
>50 (c)
(a)
(b)
(c)
Total
8.87E-02
8.70E-02
8.05E-02
7.22E-02
6.38E-02
5.52E-02
3.77E-02
1.93E-02
9.79E-03
1.94E-07
O.OOE+00
U-238
Ground
3.01E-02
2.96E-02
2.76E-02
2.51E-02
2.24E-02
1.96E-02
1.36E-02
7.10E-03
3.63E-03
7.24E-08
O.OOE+00
U-234
Inhal. (a)
1.64E-02
1.61E-02
1.47E-02
1.29E-02
1.12E-02
9.54E-03
6.25E-03
3.08E-03
1.53E-03
2.95E-08
O.OOE+00
U-238
Inhal. (a)
1.52E-02
1.48E-02
1.35E-02
1.19E-02
1.04E-02
8.80E-03
5.77E-03
2.84E-03
1.41E-03
2.72E-08
O.OOE+00
U-235
Ground
1.46E-02
1.44E-02
1.36E-02
1.25E-02
1.14E-02
1.01E-02
7.26E-03
3.93E-03
2.05E-03
4.17E-08
O.OOE+00
Water independent inhalation pathway excludes radon
"Others" includes all
Dose rates
Dose rates
2
2
2
1
1
1
9
4
2
4
0
U-234
Milk
.51E-03
.46E-03
.24E-03
.97E-03
.71E-03
.46E-03
.54E-04
.69E-04
.33E-04
.50E-09
.OOE+00
U-238
Milk Others (b)
2
2
2
1
1
1
9
4
2
4
0
.41E-03
.36E-03
. 15E-03
.90E-03
.65E-03
.40E-03
.18E-04
.51E-04
.24E-04
.33E-09
.OOE+00
7
7
6
5
5
4
2
1
7
1
0
.42E-03
.27E-03
. 65E-03
.89E-03
. 13E-03
.38E-03
.91E-03
.45E-03
.22E-04
.41E-08
.OOE+00
inhalation.
other pathways calculated by RESRAD.
for all water dependent pathways
are equal
to
O.OOE+00
for all pathways are equal to O.OOE+00 for times between
50 and 10
,000 years.
Review Draft - 9/26/94
6-39
Do Not Cite Or Quote
-------
Figure 6-13
Site V\\ -
Residential Scenario
Contribution by Radionuclide
Dose Rate (mrem/year)
m m m ™ m
o o o o o
CO N> -^ O -^
to the Total Dose Rate
vs. Time
*=*=*--_
— -*g^
•• i .
— •-
^g~^^
^•r~^r-~
— B — Tota I
**d
a _, ^^"""^^dP-scn — ' — Cs-137
"~ 5fc — aa~-.^ ~^-5k — e— Am-241
Sf— ^-»^ "v»
^^"^^^?A. X ku
"^^fts^ — — Pu-241
) 10
20
30
40 50 60
Time (years)
Site VI I
- Residential Scenario
Contribution
Total
Time
(years)
0
1
5
10
20
30
40
50
53
55
58
60
>60 (a)
by Radionuclide to the
Dose Rate (mrem/year)
Total
1.64E+00
1.59E+00
1.40E+00
1.18E+00
8.16E-01
5.33E-01
3.12E-01
1.38E-01
l.OOE-01
6.51E-02
3.16E-02
1.17E-06
O.OOE+00
l
l
l
9
6
4
2
9
6
4
2
7
0
Cs-137
.40E+00
.35E+00
.17E+00
. 76E-01
. 55E-01
. 12E-01
. 31E-01
. 71E-02
.98E-02
.46E-02
. 14E-02
.78E-07
.OOE+00
vs. Time (years)
Am-241 Pu-241
1.31E-01 1.12E-01
1.28E-01 1.10E-01
1.20E-01 1.02E-01
1.09E-01 9.30E-02
8.71E-02 7.44E-02
6.55E-02 5.58E-02
4.40E-02 3.72E-02
2.22E-02 1.86E-02
1.67E-02 1.40E-02
1.12E-02 9.30E-03
5.60E-03 4.65E-03
2.14E-07 1.77E-07
O.OOE+00 O.OOE+00
(a) Dose rates for all pathways are equal to O.OOE+00
for times between 60 and 10,000 years.
Review Draft - 9/26/94
6-41
Do Not Cite Or Quote
-------
Figure 6-14
Site VII - Residential Scenario
Cs-137 Dose Rate vs. Time
30
Time (years)
Site VII - Residential Scenario
Cs-137 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
30
40
50
53
55
58
60
>60 (c)
(a)
(b)
(c)
Inhalation
i.
i.
i.
9.
6.
4.
2.
9.
6.
4.
2.
7.
0.
Total
40E+00
35E+00
17E+00
76E-01
55E-01
12E-01
31E-01
71E-02
98E-02
46E-02
14E-02
78E-07
OOE+00
Ground
1.35E+00
1.30E+00
1.13E+00
9.41E-01
6.32E-01
3.99E-01
2.24E-01
9.44E-02
6.78E-02
4.33E-02
2.08E-02
7.57E-07
0. OOE+00
Meat Milk
3.61E-02 1.28E-02 3
3.47E-02 1.23E-02 3
2.95E-02 1.04E-02 3
2.39E-02 8.46E-03 2
1.52E-02 5.38E-03 1
9.06E-03 3.21E-03 9
4.80E-03 1.70E-03 5
1.91E-03 6.75E-04 2
1.35E-03 4.78E-04 1
8.50E-04 3.01E-04 8
4.02E-04 1.42E-04 4
1.44E-08 5.10E-09 1
0. OOE+00 0. OOE+00 0
Plant
.79E-03
.64E-03
.09E-03
.51E-03
.59E-03
.50E-04
.03E-04
.OOE-04
.42E-04
.92E-05
.21E-05
.51E-09
.OOE+00
Water independent inhalation pathway excludes radon
"Others" includes the
all
2.
2.
1.
1.
9.
5.
3.
1.
8.
5.
2.
9.
0.
Soil
28E-04
19E-04
86E-04
51E-04
59E-05
72E-05
03E-05
20E-05
52E-06
36E-06
53E-06
08E-11
OOE+00
(a) Others (b)
4
4
3
3
2
1
6
2
1
1
5
1
0
.86E-06
.67E-06
.97E-06
.22E-06
.05E-06
.22E-06
.46E-07
.57E-07
.82E-07
. 14E-07
.40E-08
.94E-12
.OOE+00
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
inhalation.
following pathways: Radon (water independent and dependent), and
the water dependent pathways (water, fish,
Dose rates
plant, meat,
and milk).
for all pathways are equal to 0. OOE+00 for times between
60 and 10
,000 years.
Review Draft - 9/26/94
6-42
Do Not Cite Or Quote
-------
Figure 6-15
1.E+01 T
E
&
60 (c)
(a)
(b)
(c)
i.
i.
i.
9.
7.
5.
3.
1.
1.
9.
4.
1.
0.
Total
12E-01
10E-01
02E-01
30E-02
44E-02
58E-02
72E-02
86E-02
40E-02
30E-03
65E-03
77E-07
OOE+00
Inhalation
(a) Soil Plant
7.74E-02 1.96E-02 8.64E-03 5
7.61E-02 1.93E-02 8.50E-03 5
7.10E-02 1.80E-02 7.92E-03 5
6.45E-02 1.63E-02 7.20E-03 4
5.16E-02 1.31E-02 5.76E-03 3
3.87E-02 9.79E-03 4.32E-03 2
2.58E-02 6.52E-03 2.88E-03 1
1.29E-02 3.26E-03 1.44E-03 9
9.66E-03 2.45E-03 1.08E-03 6
6.44E-03 1.63E-03 7.19E-04 4
3.22E-03 8.15E-04 3.60E-04 2
1.22E-07 3.10E-08 1.37E-C
)8 8
0. OOE+00 0. OOE+00 0. OOE+00 0
Meat
.56E-03
.47E-03
.10E-03
.63E-03
.71E-03
.78E-03
.85E-03
.26E-04
.94E-04
.63E-04
.31E-04
.79E-09
.OOE+00
Water independent inhalation pathway excludes radon
"Others" includes the following pathways:
all
the water dependent pathways (water,
Dose rates
for all pathways are equal to 0
Ground
2.
2.
2.
2.
2.
1.
1.
7.
6.
4.
2.
8.
0.
84E-04
82E-04
73E-04
60E-04
29E-04
90E-04
41E-04
84E-05
05E-05
15E-05
14E-05
35E-10
OOE+00
8
7
7
6
5
4
2
1
1
6
3
1
0
Milk Others (b)
.08E-05
.95E-05
. 41E-05
.73E-05
.39E-05
.04E-05
.69E-05
.35E-05
. 01E-05
.72E-06
.36E-06
.28E-10
.OOE+00
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
inhalation.
Radon (water independent and dependent), and
fish,
plant, meat,
and milk).
.OOE+00 for times between
60 and 10
,000 years.
Review Draft - 9/26/94
6-43
Do Not Cite Or Quote
-------
Figure 6-16
Site VII - Residential Scenario
-2A1 Dose Rate vs. Tirnje
30
Time (years)
—•—Total
—I—Inhalatio
n
—Q—Soil
—3K—Ground
—I—Plant
Site VII - Residential Scenario
Am-241 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
30
40
50
53
55
58
60
>60 (c)
(a)
(b)
(c)
Inhalation
i.
i.
i.
i.
8.
6.
4.
2.
1.
1.
5.
2.
0.
Total
31E-01
28E-01
20E-01
09E-01
71E-02
55E-02
40E-02
22E-02
67E-02
12E-02
60E-03
14E-07
OOE+00
(a)
7.89E-02
7.75E-02
7.18E-02
6.47E-02
5.10E-02
3.76E-02
2.47E-02
1.22E-02
9.07E-03
6.02E-03
3.00E-03
1.14E-07
0. OOE+00
Soil Ground
2.05E-02 1.91E-02 9
2.01E-02 1.89E-02 8
1.86E-02 1.82E-02 8
1.68E-02 1.72E-02 7
1.32E-02 1.50E-02 5
9.77E-03 1.24E-02 4
6.41E-03 9.09E-03 2
3.15E-03 5.04E-03 1
2.36E-03 3.88E-03 1
1.56E-03 2.66E-03 6
7.79E-04 1.36E-03 3
2.95E-08 5.33E-08 1
0. OOE+00 0. OOE+00 0
Plant
.04E-03
.88E-03
.23E-03
.42E-03
.84E-03
.31E-03
.83E-03
.39E-03
.04E-03
.90E-04
.44E-04
.30E-08
.OOE+00
2.
2.
2.
2.
1.
1.
9.
4.
3.
2.
1.
4.
0.
Meat
91E-03
86E-03
65E-03
39E-03
88E-03
39E-03
10E-04
48E-04
35E-04
22E-04
11E-04
19E-09
OOE+00
Milk Others (b)
i
i
i
i
i
8
5
2
1
1
6
2
0
.69E-04
.66E-04
.54E-04
.39E-04
.09E-04
.06E-05
.29E-05
.60E-05
.94E-05
.29E-05
.43E-06
.43E-10
.OOE+00
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
Water independent inhalation pathway excludes radon inhalation.
"Others" includes the
all
following pathways: Radon (water
the water dependent pathways (water, fish,
Dose rates
independent and dependent), and
plant, meat,
and milk).
for all pathways are equal to 0. OOE+00 for times between
60 and 10
,000 years.
Review Draft - 9/26/94
6-44
Do Not Cite Or Quote
-------
Pu-239
Am-241
Cs-137
1.96xlQ-7
2.88xlQ-7
3.03xlQ-5
500
350
O
The risk factors (based on Table 6-2), and associated cleanup concentrations at a risk level
IxlO"4, and derived cleanup volumes (based on Figure 4-16) are as follows:
Isotope Risk Factor Cleanup Cleanup
(Can/pCi/g) Cone (pCi/g) Volume (m3)
3xl05
IxlO5
3xl06
Note that the Cs-137 is limiting. Inspection of Table 5-3 indicates that, at a cleanup level of
IxlO"4, the cleanup volume is 3.67xl06 m3, which is consistent with this calculation.
Since Cs-137 is the limiting radionuclide, the direct external radiation pathway is limiting and
the discussion of uncertainties provided for Reference Site I applies here also. However,
assuming that Cs-137 is not present at the site in significant volumes, the limiting
radionuclide would be Pu-239. Am-241 would not significantly affect the cleanup volume
because, even though its risk factor is slightly greater than that of Pu-239, its concentration is
about 6 times less. Hence the following discussion of uncertainties in the cleanup volume is
limited to an assessment of the uncertainties in the Pu-239 risk factor.
The following describes the method used to derive the Pu-239 risk factor for Reference
Site VII.
For Pu-239 in an arid environment, the risk factor is dominated by the dust inhalation
pathway. For the dust inhalation pathway, the Pu-239 risk factor is approximated as follows:
Risk per pCi/g (dust) = 1 pCi/g x 200 //g/m3 x IxlO'6 g///g x 8000 m3/yr x 30 yr x SF x
AF1 x AF2x AF3 x EF
Where:
200 = airborne dust loading (//g/m3). (ANL 93b) presents a discussion
of the basis for recommending 200 //g/m3 as a default dust
loading. The discussion which follows indicates that this
parameter is a major contributor to uncertainty in the risk factor,
but 200 /-ig/m3 can be considered an upper bound when used as a
long term average value (i.e., over 30 years) at sites which are
generally non-urban.
Review Draft - 9/26/94 6-45 Do Not Cite or Quote
-------
8000 = annual breathing rate (m3/yr)
SF = 30 year inhalation slope factor (3.02xlO"8 risk/pCi inhaled)
AF1 = Adjustment factor to account for thickness of the contaminated
zone. Since the thickness of the contaminated zone is 6 cm, an
adjustment factor of 0.4 is applied to account for the assumption
that it is the average concentration in the top 15 cm that is
responsible for the airborne dust loading.
AF2 = Adjustment factor to account for indoor occupancy and
decontamination factor (assumed to be about 0.5)
AF3 = Adjustment factor to account for area of the contaminated zone
(for areas greater than IxlO4 m2, the value is 1.0; this means that
virtually all of the airborne dust at the occupied location is
assumed to be from contaminated soil.
EF = Enhancement factor to account for either the discrimination or
enhancement of the Pu concentration in the dust as compared to
the Pu concentration in the soil. A value of 1.0 is used, which is
consistent with work cited by Dan 93 for the NTS.
-7
Risk per pCi/g (dust) = 2.9x10
This agrees well with the RESRAD derived value of 1.96xlO"7. The difference is due to slight
differences in adjustment factors. If cleanup were based on this risk factor, the cleanup
concentration for a IxlO"4 risk level would be 510 pCi/g of Pu-239. Based on Figure 4-16,
this corresponds to a cleanup volume of about 6xl05 m3 instead of 3.67xl06 m3 if cleanup
were based on Cs-137.
If the thickness of the contaminated zone were greater than 15 cm and if most of the RME
individual's time were spent outdoors, this risk factor could increase to about l.SxlO"6. The
cleanup concentration would decrease to about 70 pCi/g, which would result in a cleanup
volume of 8xl06 m3. However, if a less conservative dust loading were assumed, such as 10
//g/m3, the risk factor would decrease 20 fold to l.SxlO"8. This would correspond to a cleanup
concentration of about 6700 pCi/g. Using this cleanup concentration, very little of the Pu-239
contaminated soil at the NTS would require remediation.
Review Draft - 9/26/94 6-46 Do Not Cite or Quote
-------
(DOE 93d) indicates a dust loading of 20 to 40 //g/m3 at the NTS. Reference is also made to a
total suspended solids (TSP) concentration in at 20 rural sites in the U.S. with a geometric
mean of 28 //g/m3 and a geometric standard deviation of 1.6. This would indicate an upper
end value of about 70 //g/m3. On this basis, the risk factor would be about IxlO"7 and the
cleanup concentration would be about 1000 pCi/g of Pu-239. Based on Figure 4-16, the
cleanup volume would then be about 2x105 m3.
The uncertainties in the risk factor and associated cleanup volumes are further exacerbated by
uncertainty in the enhancement factor (EF). The EF is an empirically determined relationship
between the concentration of the radionuclide in the dust to that in the soil. A discussion of
the EF is provided in (EGG 84). In general, for sites where the radionuclide contamination in
soil is associated with particles with a diameter greater than about 50 //, the likelihood of
resuspension is small (Pet 83). As the particle size decreases, the likelihood of resuspension
increases and the enhancement factor could exceed 1.0 depending on soil chemistry, moisture
content, and particle size distribution. Daniels (Dan 93) cites Shinn's work on enhancement
factors for Pu-239 at the NTS of 0.87 and 1.04. In this analysis, an enhancement factor of 1.0
was assumed.
Reference Site IX
Reference Site IX is based in part on Rocky Flats, which is dominated by Pu-239
contamination. As indicated in Table 6-2, the risk factor for Pu-239 for Reference Site IX, as
derived using RESRAD, is 1.63xlO"7. This corresponds a IxlO"4 cleanup concentration of 613
pCi/g. Based on an expanded version of Figure 4-17, the cleanup volume would be about
2xl03 m3. This is consistent with the mathematically interpolated value of 1.98xl03 m3
presented in Table 5-3.
The methods used to derive the risk factor and the associated uncertainties are similar to those
described for Pu-239 at Reference Site VII. If the dust loading were substantively less, the
cleanup concentration would increase to a point where little of the contaminated soil would
require remediation.
It is also possible that the risk factor could be higher than 1.63xlO"7. This would occur if the
slope factor were higher, the airborne dust loading were higher, and/or the adjustment factors
were all 1.0. Under these assumptions, the risk factor could increase by perhaps
Review Draft - 9/26/94 6-47 Do Not Cite or Quote
-------
10-fold, resulting in a soil cleanup concentration of about 60 pCi/g. Under these
circumstances, the cleanup volume would increase to about 3xl04, as opposed to 1.98xl03 m3.
Reference Site X
Reference Site X is based in part on Paducah. As indicated in Figure 4-18, the key
radionuclides at the site include Tc-99 and U-238. Table 6-2 indicates that the RESRAD
derived risk factors for these radionuclides are 2.52xlO"5 and 2.04xlO"5, respectively. Using
these risk factors, the cleanup concentrations required to achieve a risk level of IxlO"4 are 3.7
and 4.9 pCi/g. Applying these values to Figure 4-18, the cleanup volume is approximately
4xl05 m3 for both radionuclides. This is consistent with the mathematically interpolated value
of 5.88xl05 m3 presented in Table 5-3.
If IxlO"3 were selected as the cleanup level, the cleanup concentrations for Tc-99 and U-238
would be 37 and 49 pCi/g, respectively. Due to the differences in the patterns of
contamination, U-238 would be limiting, and the cleanup volume would be about l.SxlO5 m3,
which is consistent with the mathematically interpolated value of 1.82xl05 m3 presented in
Table 5-3.
For U-238, the critical pathway is drinking water, and as the discussion for Reference Site II
indicates, if the travel time to the aquifer were increased to beyond 1000 years, the
groundwater pathway would be eliminated, and the risk dominated by direct radiation. The
result would be an approximate 10-fold reduction in the risk factor. Given that the
groundwater pathway is of concern, the uncertainty in the risk factor could range from 0 to
about 10 times the indicated value. At the high end, cleanup to a IxlO"4 risk level would
require virtually the entire 7xl05 m3 of contaminated soil at the site to be remediated.
Reference Site XII
Reference Site XII is based in part on BOMARC. As indicated in Figure 4-19, the key
radionuclides are Pu-239 and Am-241. Table 6-2 indicates that the RESRAD derived risk
factors are 6.61xlO"7 and 7.87xlO"7 risk per pCi/g, respectively. Using these risk factors, the
cleanup concentrations required to achieve a cleanup level of IxlO"4 are 151 and 127 pCi/g,
respectively. Applying these risk factors to Figure 4-19, the cleanup volume is limited by Pu-
239 and is about 1500 m3. This is compatible with the mathematically interpolated value of
1.41xl03 m3 presented in Table 5-3.
Review Draft - 9/26/94 6-48 Do Not Cite or Quote
-------
The uncertainty in the risk factor is as discussed for Reference Site VII. That is, the risk
factor could be as much as 10 times higher to 100 times lower. If 10 times higher, the
cleanup volume required to achieve a risk level of IxlO"4 increases to about 2000 m3, if 100
times lower, it decreases to less than 500 m3.
Reference Site XIII
Reference Site XIII is based in part on Aberdeen Proving Ground. It was selected as
generally representative of a number of sites with depleted uranium contamination (DU). As
such, Reference Sites XIIIA, B, and C were created to represent the range of different
environmental settings. Table 5-3 indicates that the cleanup volume is the same for the
different settings.
Figure 4-20 indicates that U-238, U-234, and U-235 are present at the site. Table 6-2
indicates that the RESRAD derived risk factors are 1.17xlO"6, 2.12xlO"7, and 5.84xlO"6,
respectively. These correspond to a IxlO"4 risk-based cleanup level of 85, 472, and 17 pCi/g,
respectively. Applying these cleanup levels to Figure 4-20 reveals that no cleanup is required
at a cleanup level of IxlO"4. At IxlO"5, the cleanup levels are 8.5, 47, and 1.7 pCi/g,
respectively. Applying these cleanup levels to Figure 4-20, the cleanup volumes are about
700 (U-238), 0 (U-234), and 0 (U-235), respectively. U-238 is therefore limiting, as would be
expected at a DU site. This value is consistent with the mathematically interpolated value of
689m3 in Table 5-3.
As is the case for Reference Site II, the risk factors for U-238 by pathway are approximated as
follows:
Pathway Risk Factor
Groundwater = l.SxlO"6
Direct Radiation = 7.6xlO"7
Dust Inhalation = l.SxlO"7
Crop Ingestion = l.lxlO"6
Total (all paths) = 3.5xlO"6
Total = 2.0xlO"6
(without groundwater)
Review Draft - 9/26/94 6-49 Do Not Cite or Quote
-------
Since groundwater is not an issue at Reference Site XIII, a reasonable approximation of the
risk factor is 2.0xlO"6, which is consistent with the RESRAD derived value of 1.17xlO"6.
In light of the uncertainties in the U-238 risk factor described above, the cleanup volume at
risk level of IxlO"4 can range from 0 m3 to up to about 1000 m3.
Reference Site XVI
Reference Site XVI is based on the reference commercial nuclear power plant. It was
selected as generally representative of a number of sites. As such, Reference Sites XVIA, B,
and C were created to represent the range of different environmental settings. Table 5-3
indicates that the cleanup volume is the same for the different settings.
Figures 6-17 to 6-20 present the dose rate as a function of time and pathway for the two key
radionuclides at the site, Cs-137 and Co-60. As may be noted, external exposure to Co-60
from contaminated soil is the limiting pathway.
The RESRAD derived risk factors for Co-60 and Cs-137, as presented in Table 6-2, are
2.0xlO"4 and 4.95xlO"5, respectively. These correspond to a IxlO"4 risk-based cleanup level of
cleanup level of 0.5 and 2.0 pCi/g, respectively. Applying these cleanup levels to Figure 4-21
reveals that cleanup for Co-60 would require remediation of about 950 m3. The cleanup of
Cs-137 would require the remediation of about 550 m3. Therefore the Co-60 is limiting. The
Co-60 value is consistent with the mathematically interpolated value of 941 m3 in
Table 5-3.
Uncertainty in the risk factor for both Cs-137 and Co-60 could range from 0 to about 10 times
the indicated values. Since virtually all of the soil contaminated above background will
require remediation at a IxlO"4 risk level, the cleanup volume cannot be substantially larger.
Reference Site XVIII
Reference Site XVIII is based in part on Cintichem and is treated as generally representative
of research and test reactors. As such, Reference Sites XVIIIA, B, and C were created to
represent the range of different environmental settings. Table 5-3 indicates that the cleanup
volume is the same for the different settings.
Review Draft - 9/26/94 6-50 Do Not Cite or Quote
-------
Figure 6-17
1.E+02 -
1.E+01 1
re N
H
V T
X T
X
X
X.
X I
D 20 40 60 80 100 120 140 160
Time (years)
—B— Total
— *— Cs-137
— 1 — Co-60
Site XVIA, B, & C - Residential Scenario
Contribution by Radionuclide to the
Total Dose Rate (mrem/year) vs. Time (years)
Time
Total
Cs-137
Co-60
0
1
5
10
20
40
60
80
100
120
140
145
150
>-\50 (a)
l
1
6
4
I
8
4
2
1
4
1
5
9
0
. 16E+01
.03E+01
.71E+00
.13E+00
.94E+00
. 09E-01
.36E-01
.34E-01
. 16E-01
.88E-02
. 15E-02
.25E-03
. 68E-07
. OOE+00
2
2
1
1
1
7
4
2
1
4
1
5
9
0
.23E+00
.18E+00
.96E+00
.72E+00
.32E+00
. 68E-01
.34E-01
.34E-01
.16E-01
.88E-02
.15E-02
.25E-03
. 68E-07
. OOE+00
9.
8.
4.
2.
6.
4.
2.
1.
8.
4.
1.
2.
3.
0.
32E+00
14E+00
74E+00
41E+00
21E-01
06E-02
57E-03
55E-04
64E-06
06E-07
06E-08
81E-09
OOE-13
OOE+00
(a) Total dose rate is equal
between 150 years and
to 0.OOE+00 for times
10,000 years.
Review Draft - 9/26/94
6-51
Do Not Cite Or Quote
-------
Figure 6-18
1.E+02
&
150(b)
Total
1.16E+01
1.03E+01
6.71E+00
4.13E+00
1.94E+00
8.09E-01
4.36E-01
2.34E-01
1.16E-01
4.88E-02
1.15E-02
5.25E-03
9.68E-07
O.OOE+00
9
8
4
2
6
4
2
1
8
4
1
2
3
0
Co-60
Ground
.29E+00
.12E+00
.73E+00
.40E+00
.19E-01
.05E-02
.56E-03
.55E-04
. 63E-06
.05E-07
.06E-08
.81E-09
.OOE-13
.OOE+00
Cs-137
Ground
2.18E+00
2.12E+00
1.92E+00
1.68E+00
1.29E+00
7.53E-01
4.26E-01
2.30E-01
1.15E-01
4.82E-02
1.13E-02
5.19E-03
9.57E-07
O.OOE+00
Cs-137
Meat
3.16E-02
3.07E-02
2.72E-02
2.34E-02
1.72E-02
9.10E-03
4.67E-03
2.28E-03
1.02E-03
3.83E-04
8.01E-05
3.56E-05
6.38E-09
O.OOE+00
1
1
8
4
9
5
3
1
9
4
9
2
2
0
Co-60
Meat
. 62E-02
.41E-02
.06E-03
.02E-03
.94E-04
.97E-05
.47E-06
.91E-07
.71E-09
.14E-10
.79E-12
.53E-12
. 62E-16
.OOE+00
Cs-137
Milk
1.12E-02
1.09E-02
9.62E-03
8.26E-03
6.08E-03
3.22E-03
1.65E-03
8.06E-04
3.61E-04
1.36E-04
2.84E-05
1.26E-05
2.26E-09
O.OOE+00
Co-60
Plant
9.
8.
4.
2.
6.
3.
2.
1.
5.
2.
5.
1.
1.
0.
84E-03
56E-03
91E-03
45E-03
05E-04
64E-05
11E-06
17E-07
91E-09
52E-10
96E-12
54E-12
60E-16
OOE+00
Others (a)
1.25E-02
1.19E-02
9.85E-03
8.02E-03
5.61E-03
2.90E-03
1.49E-03
7.24E-04
3.24E-04
1.22E-04
2.55E-05
1.13E-05
2.03E-09
O.OOE+00
(a) "Others" includes all other pathways calculated by RESRAD.
Dose rates for all water dependent pathways are equal to O.OOE+00.
(b) Dose rates for all pathways are equal to O.OOE+00 for times between 150 and 10,000 year
Review Draft - 9/26/94
6-52
Do Not Cite Or Quote
-------
Figure 6-19
1.E-06
Site XVIA, B, & C - Residential Scenario
Co-60 Dose Rate vs. Time
20
40
60 80 100
Time (years)
120
140
-Total
-Ground
-Meat
-Plant
160
Site XVIA, B, & C - Residential Scenario
Co-60 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
40
60
80
100
120
140
145
150
>150(c)
(a)
(b)
(c)
Inhalation
9.
8.
4.
2.
6.
4.
2.
1.
8.
4.
1.
2.
3.
0.
Total
32E+00
14E+00
74E+00
41E+00
21E-01
06E-02
57E-03
55E-04
64E-06
06E-07
06E-08
81E-09
OOE-13
OOE+00
Ground Meat Plant
9.29E+00 1.62E-02 9.84E-03 2
8.12E+00 1.41E-02 8.56E-03 1
4.73E+00 8.06E-03 4.91E-03 1
2.40E+00 4.02E-03 2.45E-03 5
6.19E-01 9.94E-04 6.05E-04 1
4.05E-02 5.97E-05 3.64E-05 7
2.56E-03 3.47E-06 2.11E-06 4
1.55E-04 1.91E-07 1.17E-07 2
8.63E-06 9.71E-09 5.91E-09 1
4.05E-07 4.14E-10 2.52E-10 5
1.06E-08 9.79E-12 5.96E-12 1
2.81E-09 2.53E-12 1.54E-12 3
3. OOE-13 2.62E-16 1.60E-16 3
0. OOE+00 0. OOE+00 0. OOE+00 0
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Water independent inhalation pathway excludes
Milk
07E-03
80E-03
03E-03
14E-04
27E-04
64E-06
44E-07
45E-08
24E-09
29E-11
25E-12
23E-13
36E-17
OOE+00
radon
2
2
1
7
1
1
6
3
1
7
1
4
4
0
Soil
.96E-04
.58E-04
.48E-04
.36E-05
.82E-05
.09E-06
.36E-08
.51E-09
.78E-10
.58E-12
.79E-13
. 63E-14
.81E-18
.OOE+00
5
4
2
1
3
2
1
6
3
1
3
8
8
0
(a)
.50E-05
.78E-05
.74E-05
.37E-05
.38E-06
.03E-07
.18E-08
.52E-10
.30E-11
.41E-12
.33E-14
.60E-15
.93E-19
.OOE+00
Others (b)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
inhalation.
"Others" includes the following pathways: Radon (water independent and dependent), and
all
the water dependent pathways (water, fish,
Dose rates
plant, meat
, and milk).
for all pathways are equal to 0. OOE+00 for times between
150 and
10
,000 year
Review Draft - 9/26/94
6-53
Do Not Cite Or Quote
-------
Figure 6-20
Site XVIA, B, & C - Residential Scenario
Cs-137 Dose Rate vs. Time
40
60 80 100
Time (years)
120
140
-Total
-Ground
-Meat
-Milk
-Plant
160
Site XVIA, B, & C - Residential Scenario
Cs-137 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
40
60
80
100
120
140
145
150
>150(c)
(a)
(b)
(c)
Inhalation
2.
2.
1.
1.
1.
7.
4.
2.
1.
4.
1.
5.
9.
0.
Total
23E+00
18E+00
96E+00
72E+00
32E+00
68E-01
34E-01
34E-01
16E-01
88E-02
15E-02
25E-03
68E-07
OOE+00
Ground Meat Milk
2.18E+00 3.16E-02 1.12E-02
2.12E+00 3.07E-02 1.09E-02
1.92E+00 2.72E-02 9.62E-03
1.68E+00 2.34E-02 8.26E-03
1.29E+00 1.72E-02 6.08E-03
7.53E-01 9.10E-03 3.22E-03
4.26E-01 4.67E-03 1.65E-03
2.30E-01 2.28E-03 8.06E-04
1.15E-01 1.02E-03 3.61E-04
4.82E-02 3.83E-04 1.36E-04
1.13E-02 8.01E-05 2.84E-05
5.19E-03 3.56E-05 1.26E-05
9.57E-07 6.38E-09 2.26E-09
0. OOE+00 0. OOE+00 0. OOE+00
9
9
8
6
5
2
1
6
3
1
2
1
1
0
Plant
.46E-03
.18E-03
.14E-03
.99E-03
.14E-03
.73E-03
.40E-03
.82E-04
.05E-04
.15E-04
.40E-05
.07E-05
.91E-09
.OOE+00
5
5
4
4
3
1
8
4
1
6
1
6
1
0
Soil
. 69E-04
.53E-04
.90E-04
.21E-04
.09E-04
. 64E-04
.42E-05
.10E-05
.84E-05
.91E-06
.44E-06
.42E-07
.15E-10
.OOE+00
i
i
i
8
6
3
1
8
3
1
2
1
2
0
(a)
.17E-05
.14E-05
.01E-05
.67E-06
.37E-06
.38E-06
.73E-06
.45E-07
.78E-07
.42E-07
.97E-08
.32E-08
.37E-12
.OOE+00
Others (b)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
Water independent inhalation pathway excludes radon inhalation.
"Others" includes the following pathways: Radon (water
all
the water dependent pathways (water, fish,
Dose rates
independent and dependent), and
plant, meat
, and milk).
for all pathways are equal to 0. OOE+00 for times between
150 and
10
,000 year
Review Draft - 9/26/94
6-54
Do Not Cite Or Quote
-------
Figures 6-21 to 6-24 present the dose rate as a function of time and pathway for the two key
radionuclides at the site, Cs-137 and Sr-90. As may be noted, external exposure to Cs-137
from contaminated soil is the limiting pathway.
The RESRAD derived risk factor for Cs-137, as presented in Table 6-2, is 4.73xlO"5. This
corresponds to a 1x10"4 risk-based cleanup level of about 2.0 pCi/g. Applying this cleanup
level to Figure 4-22 reveals that virtually the entire 585 m3 will require remediation. This
value is consistent with the mathematically interpolated value of 580 m3 in Table 5-3.
Uncertainty in the risk factor for Cs-137 could range from 0 to about 10 times the indicated
value. Since virtually all of the soil contaminated above background will require remediation
at a IxlO"4 risk level, the cleanup volume cannot be substantially larger.
Reference Site XX
Reference Site XX is based in part on the Apollo plant and is treated as generally
representative of uranium fabrication facilities. As such, Reference Sites XXA, B, and C
were created to represent the range of different environmental settings. Table 5-3 indicates
that the cleanup volume is similar for the different settings.
As indicated in Figure 4-23, U-238 and U-234 are present. The RESRAD derived risk factor,
as presented in Table 6-2, are 1.72xlO"6 and 1.20xlO"6, respectively. This corresponds to a
IxlO"4 risk-based cleanup level of about 58 and 98 pCi/g, respectively. Applying a 58 pCi/g
cleanup level for U-238 to Figure 4-23 reveals that about 100 m3 will require remediation.
Applying the 98 pCi/g cleanup level for U-234 to Figure 4-23 indicates that 2000 m3 will
require remediation. This value is consistent with sites B and C and about one third the site A
cleanup volume.
As discussed earlier, uncertainty in the risk factor for U-238 could range from 0 to about 10
times the indicated value. At the upper end, the cleanup volume could increase to about
IxlO5 m3. In this case, uncertainty in the risk factor has a very large effect on the uncertainty
in the cleanup volume.
Review Draft - 9/26/94 6-55 Do Not Cite or Quote
-------
Figure 6-21
1.E+01 T
1.E-05
Site XVIIIA, B, & C - Residential Scenario
Contribution by Radionuclide
to the Total Dose Rate vs. Time
20 40 60 80 100
Time (years)
120
140
160
Site XVIIIA, B, & C - Residential Scenario
Contribution by Radionuclide to the
Total Dose Rate (mrem/year) vs. Time (years)
Time
Total
Cs-137
Sr-90
0
1
5
10
20
40
60
80
100
120
140
145
150
>150 (a)
2
2
2
1
1
8
4
2
1
4
1
5
9
0
.47E+00
.40E+00
.15E+00
.87E+00
.41E+00
. OOE-01
.45E-01
.37E-01
. 17E-01
.90E-02
. 15E-02
.25E-03
. 68E-07
. OOE+00
2
2
1
1
1
7
4
2
1
4
1
5
9
0
.21E+00
.15E+00
.94E+00
.71E+00
.31E+00
. 62E-01
.30E-01
.32E-01
.16E-01
.86E-02
.14E-02
.22E-03
. 63E-07
. OOE+00
2.
2.
2.
1.
1.
3.
1.
4.
1.
4.
6.
2.
4.
0.
60E-01
48E-01
06E-01
63E-01
01E-01
85E-02
42E-02
94E-03
59E-03
28E-04
41E-05
62E-05
32E-09
OOE+00
(a) Total dose rate is equal
between 150 years and
to 0.OOE+00 for times
10,000 years.
Review Draft - 9/26/94
6-56
Do Not Cite Or Quote
-------
Figure 6-22
1.E+01
Site XVIIIA, B, & C - Residential Scenario
Total Dose Rate vs. Time
40
60
80
Time (years)
100
120
140
160
—B—Total
—A—Cs-137
Ground
—*— Sr-90
Plant
—•—Sr-90
Meat
—6— Cs-137
Meat
—H— Sr-90
Milk
—A—Cs-137
Plant
Site XVIIIA, B, & C - Residential Scenario
Total Dose Rate (mrem/year) vs. Time
Water Independent Pathways (Inhalation Excludes Radon)
Time
(years)
0
1
5
10
20
40
60
80
100
120
140
145
150
>150(b)
2
2
2
1
1
8
4
2
1
4
1
5
9
0
Total
.47E+00
.40E+00
.15E+00
.87E+00
.41E+00
.OOE-01
.45E-01
.37E-01
.17E-01
.90E-02
.15E-02
.25E-03
. 68E-07
.OOE+00
Cs-137
Ground
2.18E+00
2.12E+00
1.92E+00
1.68E+00
1.29E+00
7.53E-01
4.26E-01
2.30E-01
1.15E-01
4.82E-02
1.13E-02
5.19E-03
9.57E-07
0. OOE+00
Sr-90
Plant
1.99E-01
1.89E-01
1.57E-01
1.24E-01
7.73E-02
2.94E-02
1.08E-02
3.78E-03
1.21E-03
3.27E-04
4.90E-05
2.01E-05
3.30E-09
0. OOE+00
Sr-90
Meat
4.54E-02
4.34E-02
3.60E-02
2.84E-02
1.77E-02
6.73E-03
2.47E-03
8.65E-04
2.78E-04
7.48E-05
1.12E-05
4.59E-06
7.56E-10
0. OOE+00
1
1
1
1
8
4
2
1
4
1
3
1
3
0
Cs-137
Meat
.49E-02
.45E-02
.28E-02
.10E-02
.09E-03
.29E-03
.20E-03
.07E-03
.81E-04
.81E-04
.78E-05
. 68E-05
.01E-09
.OOE+00
Sr-90
Milk
1.38E-02
1.32E-02
1.09E-02
8.65E-03
5.38E-03
2.05E-03
7.53E-04
2.63E-04
8.44E-05
2.28E-05
3.41E-06
1.40E-06
2.30E-10
0. OOE+00
9
9
8
6
5
2
1
6
3
1
2
1
1
0
Cs-137
Plant
.46E-03
.18E-03
.14E-03
.99E-03
.14E-03
.73E-03
.40E-03
.82E-04
.05E-04
.15E-04
.40E-05
.07E-05
.91E-09
.OOE+00
Others (a)
7.91E-03
7.65E-03
6.67E-03
5.62E-03
3.98E-03
1.99E-03
9.77E-04
4.61E-04
2.01E-04
7.44E-05
1.53E-05
6.81E-06
1.22E-09
0. OOE+00
(a) "Others" includes all other pathways calculated by RESRAD.
Dose rates for all water dependent pathways are equal to 0.OOE+00.
(b) Dose rates for all pathways are equal to 0.OOE+00 for times between 150 and 10,000 year
Review Draft - 9/26/94
6-57
Do Not Cite Or Quote
-------
Figure 6-23
Site XVIIIA, B, & C - Residential Scenario
Cs-137 Dose Rate vs» Time
40
60 80 100
Time (years)
120
140
-Total
-Ground
-Meat
-Plant
-Milk
160
Site XVIIIA, B, & C - Residential Scenario
Cs-137 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
40
60
80
100
120
140
145
150
>150(c)
(a)
(b)
(c)
Inhalation
2.
2.
1.
1.
1.
7.
4.
2.
1.
4.
1.
5.
9.
0.
Total
21E+00
15E+00
94E+00
71E+00
31E+00
62E-01
30E-01
32E-01
16E-01
86E-02
14E-02
22E-03
63E-07
OOE+00
Ground Meat Plant
2.18E+00 1.49E-02 9.46E-03
2.12E+00 1.45E-02 9.18E-03
1.92E+00 1.28E-02 8.14E-03
1.68E+00 1.10E-02 6.99E-03
1.29E+00 8.09E-03 5.14E-03
7.53E-01 4.29E-03 2.73E-03
4.26E-01 2.20E-03 1.40E-03
2.30E-01 1.07E-03 6.82E-04
1.15E-01 4.81E-04 3.05E-04
4.82E-02 1.81E-04 1.15E-04
1.13E-02 3.78E-05 2.40E-05
5.19E-03 1.68E-05 1.07E-05
9.57E-07 3.01E-09 1.91E-09
0. OOE+00 0. OOE+00 0. OOE+00
5
5
4
3
2
1
7
3
1
6
1
5
1
0
Milk
.27E-03
.12E-03
.53E-03
.90E-03
.86E-03
.52E-03
.79E-04
.80E-04
.70E-04
.40E-05
.34E-05
.95E-06
.06E-09
.OOE+00
5
5
4
4
3
1
8
4
1
6
1
6
1
0
Soil
. 69E-04
.53E-04
.90E-04
.21E-04
.09E-04
. 64E-04
.42E-05
.10E-05
.84E-05
.91E-06
.44E-06
.42E-07
.15E-10
.OOE+00
i
i
9
8
6
3
1
8
3
1
2
1
2
0
(a)
.15E-05
.12E-05
.93E-06
.53E-06
.27E-06
.33E-06
.71E-06
.32E-07
.72E-07
.40E-07
.93E-08
.30E-08
.33E-12
.OOE+00
Others (b)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
.OOE+00
Water independent inhalation pathway excludes radon inhalation.
"Others" includes the following pathways: Radon (water
all
the water dependent pathways (water, fish,
Dose rates
independent and dependent), and
plant, meat
, and milk).
for all pathways are equal to 0. OOE+00 for times between
150 and
10
,000 year
Review Draft - 9/26/94
6-58
Do Not Cite Or Quote
-------
Figure 6-24
1.E-07
Site XVIIIA, B, & C - Residential Scenario
Sr-90 Dose Rate vs. Time
20
40
60 80 100
Time (years)
120
140
160
-Total
•Plant
•Meat
•Milk
Site XVIIIA, B, & C - Residential Scenario
Sr-90 Dose Rate (mrem/year) vs. Time
Water Independent Pathways
Time
(years)
0
1
5
10
20
40
60
80
100
120
140
145
150
>150(c)
(a)
(b)
(c)
Inhalation
2.
2.
2.
1.
1.
3.
1.
4.
1.
4.
6.
2.
4.
0.
Total
60E-01
48E-01
06E-01
63E-01
01E-01
85E-02
42E-02
94E-03
59E-03
28E-04
41E-05
62E-05
32E-09
OOE+00
Plant
1.99E-01
1.89E-01
1.57E-01
1.24E-01
7.73E-02
2.94E-02
1.08E-02
3.78E-03
1.21E-03
3.27E-04
4.90E-05
2.01E-05
3.30E-09
0. OOE+00
4
4
3
2
1
6
2
8
2
7
1
4
7
0
Meat
.54E-02
.34E-02
.60E-02
.84E-02
.77E-02
.73E-03
.47E-03
.65E-04
.78E-04
.48E-05
.12E-05
.59E-06
.56E-10
.OOE+00
Milk
1.38E-02
1.32E-02
1.09E-02
8.65E-03
5.38E-03
2.05E-03
7.53E-04
2.63E-04
8.44E-05
2.28E-05
3.41E-06
1.40E-06
2.30E-10
0. OOE+00
Soil
1.59E-03
1.52E-03
1.26E-03
9.98E-04
6.21E-04
2.36E-04
8.68E-05
3.03E-05
9.74E-06
2.63E-06
3.93E-07
1.61E-07
2.65E-11
0. OOE+00
Water independent inhalation pathway excludes radon
"Others" includes the
all
(a) Others (b)
4
4
3
2
1
6
2
8
2
7
1
4
7
0
. 69E-04
.48E-04
.71E-04
.93E-04
.83E-04
.95E-05
.55E-05
.93E-06
.87E-06
.73E-07
. 16E-07
.74E-08
.80E-12
.OOE+00
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
OOE+00
inhalation.
following pathways: Radon (water independent and dependent), and
the water dependent
Dose rates
pathways
(water, fish
, plant, meat
, and milk)
for all pathways are equal to 0. OOE+00 for times between 1
50 and 10, 000 year
Review Draft - 9/26/94
6-59
Do Not Cite Or Quote
-------
Reference Site XXI
Reference Site XXI is based in part on Molycorp and is treated as generally representative of
rare earth facilities. As such, Reference Sites XXIA, B, and C were created to represent the
range of different environmental settings. Table 5-3 indicates that the cleanup volume is the
same for the different settings.
As indicated in Figure 4-24, the key radionuclide is Th-232. The RESRAD derived risk
factors, as presented in Table 6-2, for Th-232 and its daughters Ra-228+D and Th-228+D
(which grow in quickly) are 3.55xlO"7, 1.67xlO"4, and l.OSxlO"4, respectively. Since these are
assumed to be in equilibrium, the effective risk factor for Th-232 is the sum of the three, or
2.72xlO"4. This corresponds to a IxlO"4 risk-based cleanup level of about 0.36 pCi/g.
Applying this cleanup level to Figure 4-24 reveals that the entire volume of contaminates soil
of 2.89xl04 m3 would require remediation. This value is consistent with the mathematically
interpolated value of 3.18x104 m3 in Table 5-3.
The derivation of the risk and the uncertainty in the risk factor for Th-232+D is similar to that
for Cs-137 since the external dose from contaminated soil is limiting. Accordingly, the risk
factor could range from 0 to about 10 times the indicated value. Since virtually all of the soil
contaminated abo |