United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-93/137
October 1992
SEPA Superfund
Record of Decision:
USDOE Oak Ridge Reservation
(Operable Unit 17), TN
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50772-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-93/137
3. Recipient's Accession No.
Title and Subtitle
SUPERFUND RECORD OF DECISION
US DOE Oak Ridge Reservation (Operable Unit 17), TN
Seventh Remedial Action
5 Report Data
10/06/92
7. Authors)
a Performing Organization Rapt. No.
Performing Organization Name and Address
10 Project Taskwork Untt No.
11. Conlract(C) or Grant(G) No.
(Q
(G)
12 Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/800
14.
1S Supplementary Notes
PB94-964023
E Abstract (Limit: 200 word*)
The 6-acre USDOE Oak Ridge Reservation (Operable Unit 17) site, a former radioactive
treatment facility, is part of the Oak Ridge National Laboratory (ORNL) located in
Roane County, Tennessee. The site is comprised of eight treatment plots that were used
in 1968 as part of a simulated nuclear weapons fallout study in an area known as the
Waste Area Group (WAG) 13 cesium plots. During the simulation, four of the treatment
plots (Nos. 2, 4, 6, and 7) were seeded with approximately 8.8 Ci of the radioactive
compound cesium"1^7, and the remaining plots were used as controls. In 1987, USDOE
conducted a surface radiological investigation at, and around, the site to measure
existing levels, and identified elevated levels in onsite soil. Previous 1991 and 1992
RODs addressed the United Nuclear Corporation disposal site, sediment at the Y-12
Plant, sludge at the K-25 Plant, surface water at the K-25 plant, and soil at the Y-12
Plant, as OUs 2, 3, 4, 5, and 18, respectively. This ROD addresses the onsite,
radioactively-contaminated soil within the plots, as OU17. Another 1993 ROD addresses
contaminated debris, as OUS. The primary contaminant of concern affecting the soil is
cesium'
-137
a radioactive material.
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - US DOE Oak Ridge Reservation (Operable Unit 17), TN
Seventh Remedial Action
Contaminated Medium: soil
Key Contaminants: radioactive materials
b. Identifiers/Open-Ended Terms
c COSATI Field/Group
ia Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
26
22. Price
(Se*ANSI-Z39.18)
SM Instruction* on flvverss
OPTIONAL FORM 272 (4-77)
(formerly NTIS-35)
PftpflltllUnt
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EPA/ROD/R04-93/137
US DOE Oak Ridge Reservation (Operable Unit 17), TN
Seventh Remedial Action
Abstract (Continued)
The selected remedial action for this site includes excavating approximately 8,712 ft^ of
cesium-contaminated soil from each plot, that exceeds 120 pCi/g, to a depth of 2 feet;
containerizing the soil in steel boxes designed to contain low-level radioactive waste,
and transporting it onsite to WAG 6; and lining the excavated areas with clean fill and
covering them with soil and vegetation. The estimated present worth cost for this
remedial action is $709,500.
PERFORMANCE STANDARDS OR GOALS:
Soil contaminated with cesium at levels exceeding 120 PCi/g will be excavated and disposed
of onsite at WAG 6.
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DOE/OR-1059&D4
Interim Record of Decision
for Oak Ridge National Laboratory
Waste Area Grouping 13
Cesium Plots,
Oak Ridge, Tennessee
September 1992
-------
OOE/OR-1059&D4
92-225-161-70
Interim Record of Decision
for Oak Ridge National Laboratory
Waste Area Grouping 13
Cesium Plots,
Oak Ridge, Tennessee
September 1992
Prepared for
U.S. Department of Energy
Office of Environmental Restoration
and Waste Management
Prepared by
Radian Corporation
120 South Jefferson Circle
Oak Ridge, Tennessee 37830
under Contract No. DE-AC05-900R21851
Doc. IF920818.4JMS1
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TABLE OF CONTENTS
ACRONYMS AND INITTALISMS iv
PART 1. DECLARATION 1-1
SITE NAME AND LOCATION -2
STATEMENT OF BASIS AND PURPOSE -2
ASSESSMENT OF THE SITE -2
DESCRIPTION OF SELECTED REMEDY -2
STATUTORY DETERMINATION -3
APPROVALS 1-4
PART 2. DECISION SUMMARY 2-1
SITE NAME, LOCATION, AND DESCRIPTION 2-2
SITE HISTORY AND ENFORCEMENT ACTIVITIES 2-2
HIGHLIGHTS OF COMMUNITY PARTICIPATION 2-5
SCOPE AND ROLE OF THE RESPONSE ACTION 2-5
SUMMARY OF SITE CHARACTERISTICS 2-6
SUMMARY OF SITE RISKS 2-6
DESCRIPTION OF ALTERNATIVES 2-7
Alternative 1—No Action 2-8
Alternative 2—Shielding . . . -. 2-8
Alternative 3—Excavation and Storage at a Currently Operating
Waste Management Facility 2-8
Alternative 4—Excavation and Disposal at the WAG 6 Low-Level
Waste Silos 2-9
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 2-9
Overall Protection of Human Health and the Environment 2-10
Compliance with ARARs 2-10
Long-Term Effectiveness and Permanence 2-10
Reduction of Toxicity, Mobility, or Volume Through Treatment .... 2-10
Short-Term Effectiveness 2-10
Implementability 2-10
Cost 2-12
Regulatory Agency Acceptance 2-12
Community Acceptance 2-12
The Selected Remedy 2-12
STATUTORY DETERMINATIONS 2-13
Protection of Human Health and the Environment 2-13
Compliance with ARARs 2-15
Cost Effectiveness 2-15
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TABLE OF CONTENTS (continued)
Use of Permanent Solutions and Alternative Treatment
Technologies 2-15
Preference for Treatment 2-15
EXPLANATION OF SIGNIFICANT CHANGES 2-16
BIBUOGR/ HY 2-16
PART 3. RESPONSIVENESS SUMMARY 3-1
Overview 3-2
Background on Community Involvement 3-2
Summary of Comments Received and Agency Responses 3-2
Remaining Concerns 3-3
Appendix A. MEETING MINUTES AND LETTER OF RESPONSE
W3MU.4JVC1 111
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ACRONYMS AND INTTIALISMS
ALARA as low as reasonably achievable
ARAR applicable or relevant and appropriate requirement
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
DOE U.S. Department of Energy
EPA U.S. Environmental Protection Agency
FS feasibility study
IROD Interim Record of Decision
O&M operation and maintenance
ORNL Oak Ridge National Laboratory
ORR Oak Ridge Reservation
pCi/g picocuries per gram
RI remedial investigation
RME reasonable maximum exposure
SR Tennessee State Route
TBC to be considered
TCA Tennessee Code Annotated
TDEC Tennessee Department of Environment and Conservation
WAG Waste Area Grouping
IV
HM2/92
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PARTI. DECLARATION
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SITE NAME AND LOCATION
Waste Area Grouping (WAG) 13
Oak Ridge National Laboratory (ORNL)
Oak Ridge Reservation (ORR)
Oak Ridge, Tennessee
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected interim remedial action for the ORNL
WAG 13 in Oak Ridge, Tennessee. This action was chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980,
as amended by the Superfund Amendments and Reauthorization Act of 1986, and, to the extent
practicable, the National Oil and Hazardous Substances Pollution Contingency Plan. This
decision is based on the administrative record file for this site.
The State of Tennessee and the U.S. Environmental Protection Agency (EPA) concur with
this interim action for the WAG 13 remediation.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected hi this Interim Record of Decision (IROD), may
present a current or potential threat to public health, welfare, or the environment.
DESCRIPTION OF SELECTED REMEDY
The purpose of this interim action is to reduce the risk to human health and the
environment resulting from current elevated levels of gamma radiation on the site and at areas
accessible to the public and adjacent to the site. To achieve this, only the cesium-contaminated
soil within the plot will be addressed. This is not the final action planned for WAG 13.
Subsequent actions are planned to fully address the remaining threats posed by the conditions at
the site. As mandated in CERCLA, the site will be evaluated during the Remedial Investigation
(RI)/Feasibility Study (FS) for the site.
nanii.4iMSi 1-2 nmm
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The major components of the interim action remedy are the following:
• excavate cesium-contaminated soil until residual contamination is
<: 120 pCi/g;
• containerize the excavated soil in steel boxes designed for the storage of
low-level radioactive waste;
• transport the excavated soil to WAG 6 low-level waste silos by truck; and
• line each excavated plot with a permeable liner and backfill with a clean
compacted fill material and a topsoil layer.
Interim remedial action on WAG 13 prior to completion of the RI/FS will provide
additional benefits consistent with the goals of CERCLA, including:
• preventing a known source of cesium-contaminated sediment from producing
elevated levels of gamma radiation on WAG 13 and to areas accessible to the
public,
• reducing further degradation to the environment by eliminating the source of
contamination,
• reducing the difficulty and risk associated with future surveillance,
maintenance, and remedial activities on WAG 13.
STATUTORY DETERMINATION
This interim action protects human health and the environment, complies with federal and
state applicable or relevant and appropriate requirements (ARARs) for this limited-scope action,
and is cost-effective. This action is interim and is not intended to use permanent solutions and
alternative treatment (or resource recovery) technologies to the maximum extent practicable,
given the limited scope of the action. Again, this action is not a final remedy for the WAG.
Therefore, the statutory preference for remedies that employ treatment that reduces toxicity,
mobility, or volume as a principal element will be addressed at the time of the final response
action. Subsequent actions are planned to fully address the remaining threats posed by the site.
Because this is an IROD, review of this WAG and of this remedy will be continuing as part of
the development of the final remedy for the site.
1I.4IMM
1-3 to/ana
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APPROVALS
Manager
U.S. Department of Energy (DOE)
Oak Ridge Field Office
Date
"LA
Director, DOE Oversight Division!
State of Tennessee
Tennessee Department ofvEnvironment and
Date
mservation
Regional Administrator
U.S. Environmental Protection Agency, Region IV
Date
P9»1I.«IMS1
1-4
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PART 2. DECISION SUMMARY
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SITE NAME, LOCATION, AND DESCRIPTION
WAG 13 is part of ORNL on the ORR CERCLA Site in Roane County, Tennessee.
ORNL is part of the federally owned ORR, managed for DOE by Martin Marietta Energy
Systems, Inc. The WAG 13 cesium plots are in an approximately 6-acre grassy field 330 ft north
of the Clinch River at mile 20.5 and 1.3 miles south of the intersection of Bethel Valley Road
and Tennessee State Route (SR) 95 (Fig. 1).
The WAG 13 cesium plots are enclosed by a perimeter fence approximately 1000 ft by
250 ft. There are eight treatment plots that were used for a simulated nuclear weapons fallout
tody undertaken by ORNL. Each plot is 33 by 33 ft and is fenced with sheet metal extending
18 in. below the surface and 24 in. above surface. There are no other structures on the site. The
elevated gamma radiation levels emitted from these plots pose a potential threat to human health
and the environment.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
In August 1968, to simulate conditions of a nuclear fallout, four of the treatment plots
(Nos. 2,4, 6, and 7) were contaminated (seeded) with mCs; the remaining four plots were used
as uncontaminated controls (Fig. 2). The seeding was achieved by spreading "'Cs-fused sand
panicles evenly over the plots at 72 g/m2. Each test plot received 2.2 Ci of lS7Cs, while the
control plots received none.
A surface radiological investigation was conducted at and around the site between June
1987 and March 1988 by ORNL's Measurement and Development Group (Yalcintas et al. 1988).
Outside the fenced area, radiation levels were measured at 23 locations on the Clinch River and
9 locations along the riverbank. Radiation levels were also measured inside the fenced area. The
summary of site characteristics section in this IROD provides more details regarding radiation
levels.
On December 21, 1989, the ORR was placed on CERCLA's National Priorities List,
which mandates specific requirements that environmental restoration activities must follow. DOE
must also operate in compliance with the National Environmental Policy Act. An Interim
Remedial Measures Study (Radian July 1992) for the WAG 13 cesium plots was completed in
July 1992 to determine the best alternative for reducing the health threat posed by the gamma
radiation in the plots.
F9anit.«>M3i 2-2
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2-3
RADIAN
Date: 1992
Location of the WAG 13 cttium
plot, on th« DOE ORR
Environm«nt*l Rcitorstion Program
Fig.1
D92D22HRD31
060CV92
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2-4
•MCMftn
RADIAN
Dttt: 1982
Environment*) Restoration Program
WAO 13 •«• imp shewing the
location of th« o**)um plot*.
Rg. 2
D92022S.1RD51
060O92
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HIGHLIGHTS OF COMMUNITY PARTICIPATION
The Proposed Plan for the ORNL WAG 13 Interim Remedial Action was released to the
public in July 1992. The Proposed Plan was made available to the public in the administrative
record maintained at the Information Resource Center in Oak Ridge, Tennessee. Notice of
availability for the Proposed Plan was published in the Oak Ridger on July 10,12, and 15,1992;
in the Knoxville News-Sentinel on July 10, 12, and IS, 1992; and in the Roane County News on
July 13, IS, and 17, 1992. A public comment period was held from July 14 to August 12, 1992.
A public meeting was not scheduled, but opportunity for a meeting was offered in the published
notice of availability.
A response to the comments received during the comment period is included in the
Responsiveness Summary, which is Part 3 of this IROD. This decision document presents the
selected interim remedial action for the ORNL WAG 13 cesium plots. This selection was made
in accordance with CERCLA, as amended by the Superrund Amendments and Reauthorization
Act of 1986, and to the extent feasible, the National Contingency Plan.
SCOPE AND ROLE OF THE RESPONSE ACTION
The goal of this response action is to reduce the risk to human health and the environment
resulting from the current elevated levels of gamma radiation on WAG 13. During this interim
action, only the cesium-contaminated soil within the plots will be addressed. Excavating these
soils and placing them in WAG 6 low-level waste silos will prevent a known source of cesium-
contaminated sediment from producing elevated levels of gamma radiation on WAG 13.
Subsequent actions under CERCLA are planned to fully address the threats posed by the
remaining exposure pathways at the site. These may include, but are not limited to, the soil
outside the plot boundaries, the soil beneath the depth of excavations completed during the
interim action, groundwater, and surface water. The remaining areas of the site will be evaluated
during the RI/FS, as mandated in CERCLA. This interim remedial action is consistent with
planned future activities at the site. In particular, this interim action will provide a reduction in
the difficulty and risk associated with future surveillance, maintenance, and remedial activities.
TOOIU.4JMJI 2-5 1002/92
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SUMMARY OF SITE CHARACTERISTICS
Contamination on WAG 13 has resulted solely from the intentional deposition of >)7Cs
for the purpose of gaining knowledge of the effects of nuclear fallout. A total of 8.8 Ci was
spread over the four test plots and has decayed to 5.1 Ci as of June 1992.
The surface radiological investigation conducted at the site concluded mat the maximum
exposure to the public would be approximately 0.019 mR/h along the shoreline closest to the
OTCs plots and up to 0.150 mR/h at the perimeter fence. Gamma ray exposure rates measured
at plot plot boundaries within the fenced area ranged from 1.3 to 35 mR/h (Yalcintas et al. 1988).
/
Soil samples taken within the plots indicate that the I57Cs has been detected above 1 pCi/g
(detection limit) at depths up to 3 ft.
SUMMARY OF SITE RISKS
A preliminary health risk assessment study was conducted for WAG 13 and the only
contaminant of concern was determined to be "7Cs (Radian July 1992). Cesium-137 is a beta
emitter (512 KeV) that also releases gamma at 661 KeV and has a 30-year half-life. Although
1987 soil samples from two locations between the contaminated plots and the nearby creek bed
show that 137Cs contamination has migrated (ORNL 1988), the scope of this action is limited to
contamination in the test plots. Therefore, the risk analysis does not consider possible
contributions from 137Cs that may have migrated beyond the test plots. External exposure to
ionizing radiation poses the majority of risk to the exposed populations and was determined to
be the dominant pathway of concern for all three scenarios.
The exposure scenarios examined in the preliminary health risk assessment were:
• a worker who mows the area,
• a fisherman/boater on the Clinch River who comes within 150 ft of the cesium
plots, and
• a future on-site homesteader who lives inside the area that is currently fenced.
Lifetime cancer risks associated with the WAG 13 cesium plots were calculated assuming
reasonable maximum occupational exposure for the worker mowing the area, reasonable
maximum exposure (RME) for a fisherman/boater on the Clinch River, and RME for an on-site
homesteader. RME assumptions for the preliminary health risk assessment were adopted from
ORNL's Radiation Exposure from a Cesium-Contaminated Field (Yalcintas et al. 1988).
ranii.4M5i 2-6 wan
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The RME scenario for the worker assumes that an individual spends 25 h/year on-site
for 25 years and is exposed to an average gamma rate of 150 jiR/h measured on-site. The RME
scenario for the fisherman/boater assumes that an individual spends 52 h/year (1 h/week) on the
Clinch River near the WAG 13 cesium plots for 30 years and is exposed to a maximum gamma
rate of 19 pR/h measured on the Clinch River. The RME scenario for the future on-site
homesteader assumes that an individual spends 5600 h/year (16 h/d for 350 d) for 30 years inside
the fence and is exposed to an average gamma rate of 4 mR/h.
The risk to the worker was estimated to be 1 x 10~J (1 in 1000 chances of developing
cancer). The risk to the fisherman/boater on the Clinch River was estimated to be 2 x 10"3, and
risk to the on-site homesteader was calculated to be 3 x 10"1.
Calculated risks from lifetime exposure to radionuclides and chemicals were compared
to the EPA's target risk range of 1 x 10* to 1 x 10~*. Any risk values greater than 1 x 10~*
(1 in 10,000 chances of developing cancer) are unacceptable, and any risk values less than 1 x
10* (1 in 1,000,000 chances of developing cancer) are acceptable by EPA. Acceptance of risks
between 1 x 10* and 1 x 10" depends on site-specific conditions (i.e., population exposure).
The risk to the fisherman/boater falls within EPA's acceptable risk range. Although
exposure to the worker is within DOE guidelines (DOE Order 5480.11), risks to the worker
mowing around the cesium plots and to the on-site homesteader exceed EPA's target risk range.
Ecological risk to plants and animals has not been quantitatively analyzed, but removal
or shielding of the contaminated soil will have a positive benefit for all risk scenarios. The
WAG 13 area will need further evaluation for the CERCLA Ecological Risk Assessment and
Natural Resource Damage Assessment during the RI.
If no interim remedial action is taken, actual or threatened releases of hazardous
substances from the WAG 13 cesium plots may present a current or potential threat to public
health, welfare, or the environment.
DESCRIPTION OF ALTERNATIVES
This section provides a description of how each alternative would address the
contamination found at WAG 13. Four alternatives are presented. These alternatives are not
intended to remediate the entire WAG 13 site. Rather, they are intended to reduce the threat to
human health, and to reduce further degradation of the environment resulting from elevated
gamma radiation exposures. Remediation of the entire site will be addressed in future CERCLA
actions.
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Alternative 1—No Action
CERCLA requires that the no-action alternative be evaluated to serve as a baseline for
comparison at each site. Under this alternative, no further action would be taken to reduce the
risk to human receptors from the current elevated levels of gamma radiation. Implementing this
alternative would involve no additional costs.
Alternative 2—Shielding
Shielding involves placing reinforced concrete boxes over each cesium plot. The boxes
will deflect and contain the gamma radiation within the box. After shield installation, gamma
radiation exposure rates will be reduced to 9 jiR/h at the perimeter fence, thus reducing risk to
the general public on or near the Clinch River. Besides reducing the level of gamma radiation
to 9 pR/h, the shields would reduce rainwater infiltration into the plots, thereby reducing to some
extent potential contaminant transport caused by rainwater percolation to the groundwater.
Fabrication and construction of the shields would take about 2 months. The present
worth cost for this alternative, including implementation or capital cost (including engineering
design and construction) and operation and maintenance (O&M) cost, is estimated to be
$203,000. These costs were developed for comparative purposes only and may not represent
actual costs.
Alternative 3—Excavation and Storage at a Currently Operating Waste Management Facility
Alternative 3 entails excavating 5200 ft3 of cesium-contaminated soil from within the
plot boundaries. Excavation of the contaminated soils would reduce radiation exposures to
background levels. Excavated material will be containerized in steel boxes designed for the
storage of low-level radioactive waste and transported by truck to the Interim Waste Management
Facility (IWMF) at ORNL's WAG 6.
Following excavation, each plot will be lined with a (permeable) liner and backfilled with
clean compacted fill material and a topsoil layer. Grass will then be established to control
erosion from the site.
The remedial action for this alternative will take approximately 2 days. The present
worth cost for mis alternative, including implementation or capital cost (including engineering
design and construction) and O&M cost, is estimated to be $546,000. These costs were
developed for comparative purposes only and may not represent actual costs.
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Alto-native 4—Excavation and Disposal at the WAG 6 Waste Consolidation Area
Excavation and transportation of the soil and construction activities will be conducted
using the same volume , techniques, and requirements as Alternative 3. Under this alternative,
the soil is transported to the WAG 6 waste consolidation area, which is scheduled for closure
under a CERCLA remediation in the near future. The waste consolidation area is an engineered
waste disposal site that will be designed and operated using best manag^pfpt practices. The
design and operation emphasizes isolation from groundwater, surface water, and infiltration, as
well as void control to minimize settling. By placing the soil beneath an engineered cover
system, the potential for contaminants to enter the environment is further decreased.
Disposal of the WAG 13 soil at WAG 6 is expected to have only negligible impact; the
amount of contamination and material volume to be excavated from the WAG 13 cesium plots
is very small in comparison to that already existing at WAG 6. Large amounts of 137Cs and other
radionuclides are already present at WAG 6. The total amount of material to be placed in WAG
6 represents about one-twentieth of one percent of the volume and about one-two hundredth of
one percent of the radiological contamination present in WAG 6.
Implementation of this remedial action will take approximately 2 days, not including time
for waste disposal site construction. The present worth cost for this alternative, including capital
cost(including engineering design and construction), O&M cost, is $81,000. These costs were
developed for comparative purposes only and may not represent actual costs. The disposal
techniques for this alternative has been modified as noted in the section titled Explanation of
Significant Changes (page 2-16)
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
This section provides a basis for determining which alternative provides the "best balance
of tradeoffs" with respect to nine evaluation criteria. These criteria are:
• overall protection of human health and the environment;
• compliance with ARARs;
• long-term effectiveness and permanence;
• reduction of toxicity, mobility, or volume through treatment;
• short-term effectiveness;
• implementability;
• cost;
• regulatory agency acceptance; and
• community acceptance.
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Overall Protection of Human Health and the Environment
i
Alternatives 2, 3 and 4 reduce the gamma radiation exposure to acceptable levels at the
WAG 13 perimeter fence. Alternative 1 does not affect the current level of exposure to human
health and the environment due to the plots.
Compliance with ARARs
Table 1 provides a summary of ARARs for the remedial action.
Alternatives 3 and 4 complies with all of the listed ARARs. Alternative 2 complies with
all of the ARARs except transportation, which does not apply. Alternative 1 does not meet
requirements set forth by DOE orders for exposure of the public and workers to radiation caused
by a DOE facility. DOE is responsible for ensuring that all DOE activities are operated so that
the radiation dose to individuals will be as low as reasonably achievable (ALARA). Alternative 1
does not allow this.
Long-Term Effectiveness and Permanence
Alternatives 3 and 4 permanently reduces the radiation risk posed by the WAG 13 cesium
plots. Alternative 2 provides only a temporary solution and does not prevent potential
groundwater contamination. Alternative 1 provides no long-term effectiveness.
Reduction of Toxicity, Mobility, or Volume Through Treatment
None of the alternatives reduce toxicity, mobility or volume through treatment. Viable
treatment options for low-level radioactive waste do not exist at this time.
. Short-Term Effectiveness
By removing the contamination. Alternatives 3 and 4 both provide effective short-term
solution to the gamma radiation emanating from the plots. Alternative 2 will require a short
period for the construction of the concrete boxes and will then provide the required reduction in
off-site radiation exposure. Alternative 1 provides no short-term solution. Alternatives 2, 3 and
4 would result in some remedial activity worker exposure.
Implementability
Alternatives 2 and 4 are equally implementable using conventional materials and
construction techniques. Alternative 3 is not currently implementable due to current DOE and
Martin Marietta operational restrictions which prohibit the storage of soils at the Interim Waste
mnis.4M5t 2-10
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Table 1. Summary of ARARs
ARAR category
Requirement
Gtations
Location-Specific
Floodpituns
Action-Specific
On-aite construction/excavation
or handling of materials
Surface water controls
Worker protection
Public health protection
Transportation
Waste Packaging and Handling
Waste management
Must ;: to avoid Averse unp ~;
and c-Liimize potential harm du.
to diversion of floodwaters
Precautions must be taken to
prevent particulate matter from
becoming airborne. Fugitive
dust emissions must be
controlled
Must ensure compliance with the
substantive requirements of the
state permitting process.
Implement good site planning
and best management practices
to control storm water
discharges
Must adhere to health and safety
standards
Must keep radiation doses for
individuals ALARA
Must meet requirements that
address preparation of shipping
papers, container marking,
labeling, vehicle placarding,
packaging, testing of packages
and containers, and carriage by
public highway
Must adhere to packaging and
handling requirments
Must handle and dispose of
waste in a manner that is
protective of public health and
the environment
40 Cl R 6 Appendix A 10 CFR
1022
(Applicable)
40 CFR 50.6 and
TCA 1200-3-8-.01 (Applicable)
TCA 69-3-108
TCA 1200-4-3
TCA 1200-4-4
TCA 1200-4-10-.05
40 CFR 122
(Applicable)
Radiation protection standards,
29 CFR 1910, (Applicable) and
DOE Order 5480.11 (TBC)
DOE Orders 5400.5 and 5820.2A
(TBC)
49 CFR 172, 173, 177, and 178
and 10 CFR 71 (Applicable)
DOE Order 5480.3 (TBC)
*10 CFR 61.56(a)(lK7) and
.56
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Management Facility. (Bill Adams of DOE and representatives of Energy Systems agreed that
soils should not be stored at the Interim Waste Management Facility.)
Cost
Alternative 1 involves no cost. Alternative 2 costs $203,000. Alternative 3 costs
$546,000. Alternative 4 costs $81,000.
State Acceptance
The State of Tennessee has reviewed the alternatives proposed for interim action at
WAG 13. TDEC concurs with the selection of Alternative 4.
Community Acceptance
During the public comment period for the Proposed Plan, a single comment was
presented about the proposed alternative. The Responsiveness Summary of this IROD addresses
the questions and comments from the public in detail.
The Selected Remedy
Based on consideration of the requirements of CERCLA, the detailed analysis of
alternatives, and public comments, the most appropriate remedy for the WAG 13 cesium plots
is a variation of Alternative 4, Excavation and Disposal at WAG 6 Waste Consolidation Area.
The disposal techniques for the selected remedy have been modified as noted in the section titled
Explanation of Significant Changes (Page 2-16)
Contaminated soil will be excavated from each plot until the residual contamination is
< 120 pCi/g, and containerized in steel boxes designed for the storage of low-level radioactive
waste. The boxes will be transported to WAG 6 by truck. WAG 6 is scheduled to be closed
under a CERCLA remediation in the near future. Each excavated plot will be lined with a
permeable liner, backfilled with clean compacted fill material, covered with topsoil, and
revegetated.
The purpose of this interim action is to reduce the current human health and
environmental risk to off-site receptors immediately outside the perimeter fence and at the banks
of the Clinch River. Existing conditions at the site have been determined to pose a lifetime
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cancer risk that exceeds EPA's target risk range to a worker mowing around the cesium plots and
an on-site homesteader. Following the remedial action, the risk due to the cesium plots will be
reduced to the equivalent of that posed by nonoccupational exposure limits.
The cost of the selected remedy, outlined in Table 2, is based on an estimated excavation
depth of 2 ft. The cost estimate was made assuming that there would be no waste preparation
activities before disposal. If waste preparation is required, there will be a one-time fee based on
the total volume of waste placed in WAG 6. Other changes may be made to the remedy as part
of the remedial design and construction processes. Such changes, in general, reflect
modifications resulting from the engineering design process.
STATUTORY DETERMINATIONS
Under its legal authorities, DOE's primary responsibility at CERCLA sites is to undertake
remedial actions that achieve adequate protection of human health and the environment. In
addition, Sect. 121 of CERCLA establishes several other statutory requirements and preferences.
These specify that when complete, the selected remedial action for this site must comply with
applicable or relevant and appropriate environmental standards established under federal and state
environmental laws unless a statutory waiver is justified. The selected remedy must also be cost-
effective and utilize permanent solutions and alternative treatment or resource recovery
technologies to the maximum extent practicable. Finally, the statute includes a preference for
remedies that employ treatment that permanently and significantly reduce the volume, toxicity,
or mobility of hazardous wastes as their principal element. The following sections discuss how
the selected remedy meets these statutory requirements.
Protection of Human Health and the Environment
The selected remedy provides protection of human health by mitigating the existing risk
to off-site receptors on the Clinch River that results from gamma radiation emissions from the
WAG 13 cesium plots. It also reduces the radiological emissions at the plot perimeter fence to
acceptable levels. Excavating the contaminated soil also provides reduced risk to future on-site
workers by reducing the radiation levels at the plots. The risk associated with an on-site worker
(25 h/year on-site for 25 years) after the remediation is complete is estimated to be 2.9 x 10*.
The estimated short-term radiological risk to on-site workers associated with the remedial action
is estimated to be 7 x Ifr*.
TOOUI.4JM3I 2-13 ana/92
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Table 2. Estimated cost of the Selected Remedy
Item Cost(S)
Coturtruction cost (labor, nw'fn*'", f^ equipment)
Soil excavation and containerizatioa
Soil tnnsportation and silo construction
Restoration of pits
Subtotal
Mobilization® 25%
Contractor's overhead and profit © 20%
Total construction cost
Engineering design cost <0> 20%
Contingency ® 25%
Total present worth cost
220,500
113,000
4,000
337,500
84,000
68,000
489,500
98,000
122,000
709,500
Assumptions: 8,712 ft1 soil excavated
40% expansion factor
127 B-25 boxes 0 $1,500 each
11 silos ® $10,000 each
TOW1I.4JMS1 2-14 tomm
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The environment will benefit from the selected remedy through the elimination of a
source of continued contamination. Radiation exposures to local animal and plant life will be
reduced, and contaminated vegetation will be removed and replaced with a grass cover, resulting
in a better animal habitat.
Compliance with ARARs
The selected remedy will comply with all the ARARs shown in Table 1, and a waiver
is not requested. Also, compliance with applicable U.S. Department of Transportation
regulations will be maintained. The 0.2-mile segment of SR95 between the WAG 13 cesium
plots and WAG 6 access roads may be closed temporarily while the contaminated soils are being
transported. This will be done during the day and should not adversely affect traffic during shift
change.
Cost Effectiveness
Because the selected remedy will involve removing the contamination from the site, it will
provide a permanent solution and is therefore the most cost-effective alternative available.
Use of Permanent Solutions and Alternative Treatment Technologies
The selected remedy provides a permanent solution to the existing and future threats
posed by the existing WAG 13 cesium plots. It does not utilize a treatment technology because
a viable method is not available. This will be discussed in the following section.
The selected remedy will be effective immediately after the initial construction period.
After the contaminated soil is removed and transported to WAG 6, only residual contamination
is expected to remain.
Among the alternatives, the selected remedy is equally implementable using conventional
materials and construction techniques.
Preference for Treatment
At this time, viable technologies for treatment of low-level radioactive waste are not
available; containment and storage allows the radioactivity to decay and appears to be the most
desirable method of low-level radioactive waste mitigation.
Two treatment methods exist for soils: stabilization and vitrification. However, these
methods are more costly than the selected alternative, would present greater risks to workers, and
would not mitigate the toxicity of the 137Cs further than the selected alternative.
mnu.«iMsi 2-15 10*0/92
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EXPLANATION OF SIGNIFICANT CHANGES
Following the release of the Proposed Plan for public review, it was found that the Waste
Consolidation Area may not be ready to receive wastes in time to be used for this interim
remedial action. Another disposal option, low level waste silos, consistent with the intent of the
preferred alternative was identified and selected. The new disposal option provides better
confinement of the wastes from the environment than the Waste Consolidation Area. Silo
disposal is a currently utilized disposal technology utilizing an engineered facility within WAG
6 designed and operated to isolate the waste material from surface water and groundwater, control
subsidence, and provide radiation protection. Additional costs, as shown in Table 2, for silo
disposal are attributed to the cost of containers and the inclusion of silo construction costs.
Containers were not planned for disposal in the consolidation area and facility construction costs
were assumed to be included in the WAG 6 remedial action effort.
BIBLIOGRAPHY
ORNL 1988. Environmental Data Package for the Environmental Research Areas (WAG 13),
ORNL/RAP-48.
Radian (Radian Corporation) July 1992. Interim Remedial Measures Study for ORNL WAG 11,
DOE/OR-1015D2, Oak Ridge, Tenn.
Radian July 9, 1992. Proposed Plan for the ORNL WAG 13 Interim Remedial Action,
DOE-OR-1022D3, Oak Ridge, Tenn.
Yalcintas et al. 1988. Radiation Exposures from a Cesium-Contaminated Field, ORNL/RAP-46.
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