vvEPA
United States
Environmental Protection
Agency
Air And Radiation
(ANR-459)
May 1991
Diffuse Norm
Waste Characterization
And Priiminary
Risk Assessment
Draft
Printed on Recycled Paper
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-DRAFT-
- DIFFUSE NORM WASTES -
f ASTE CHARACTERIZATION AND RISK ASSESSMENT
Prepared By
SC&A, Inc.
1311 Dolley Madison Boulevard
McLean, Virginia 22101
(703) 893-6592
and
Rogers & Associates Engineering Corp.
P.O. Box 330
Salt Lake City, Utah 84110-0330
and
Roy F. Weston, Inc.
5301 Central Ave., N.E.
Albuquerque, New Mexico 87108
Contract No. 68-D90170
Work Assignment 1-59
Prepared For
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Radiation Programs
401 M Street, S.W.
Washington, D.C. 20460
William E. Russo/James M. Gruhlke
Work Assignment Manager
May 1991
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TABLE OF CONTENTS
Chapter Page No.
EXEC! FIVE SUMMARY ES-1
A. INTRODUCTION A-l
B.1 URANIUM MINING OVERBURDEN B-l-1
1.1 Introduction B-l-1
1.2 Overview of the Uranium Mining Industry B-l-2
1.2.1 Surface Mining B-l-2
1.2.2 Underground Mining B-l-6
1.2.3 Other Mining Methods B-l-7
1.3 Ore and Waste Production B-l-7
1.3.1 Waste Volume Projections B-l-8
1.3.2 Reclaimed Versus Unreclaimed Material B-l-12
1.3.3 Uranium Overburden Utilization B-l-13
1.3.4 Twenty-Year Projection of Unreclaimed Waste B-l-16
1.4 Radiological Properties of Uranium Mine Waste B-l-19
1.4.1 Radionuclide Concentrations B-l-19
1.4.2 Radon Flux Rates B-l-20
1.4.3 External Radiation Exposure Rates B-l-21
1.5 Generic Site Parameters and Sector Summary B-l-22
1.5.1 Generic Overburden Site B-l-22
1.5.2 Population Exposure B-l-22
1.5.3 Radionuclide Concentrations B-l-23
B.I References B-l-R-1
B.2 PHOSPHATE AND ELEMENTAL PHOSPHOROUS WASTES B-2-1
2.1 Introduction B-2-1
2.2 Overview of Phosphate Industry B-2-2
2.2.1 Phosphoric Acid - Wet-Process B-2-5
2.2.2 Elemental Phosphorous - Thermal Process B-2-8
2.3 Phosphogypsum Stacks and Elemental Phosphorous Wastes B-2-11
2.3.1 Volume of Waste Materials B-2-11
2.3.2 Phosphogypsum and Slag Utilization B-2-14
2.3.3 Twenty-Year Waste Inventory B-2-17
2.4 Radiological Properties of Phosphogypsum and Slag B-2-20
2.4.1 Radionuclide Concentrations of Phosphogypsum
and Slag B-2-20
2.4.2 Radon Flux Rates B-2-23
2.4.3 External Exposure Rates B-2-25
2.5 Generic Site Parameters and Sector Summary B-2-28
2.5.1 Generic Phosphogypsum Stack B-2-28
11
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TABLE OF CONTENTS
(Continued)
Chapter Page No.
(B.2) 2.5.2 Population Exposure B-2-29
2.5.3 Radionuclide Concentrations B-2-29
B.2 References B-2-R-1
B.3 PHOSPHATE FERTILIZERS B-3-1
3.1 Introduction B-3-1
3.2 Production of Phosphate Fertilizers B-3-2
3.2.1 Phosphoric Acid Production B-3-2
3.2.2 Phosphate Fertilizer Production B-3-3
3.3 Phosphate Fertilizer Consumption B-3-3
3.3.1 Consumption and Application Rates B-3-3
3.3.2 Twenty-Year Fertilizer Production Estimai ;s B-3-7
3.4 Radiological Properties of Fertilizers B-3-8
3.4.1 Radionuclide Concentrations B-3-8
3.4.2 Radon Flux Rates B-3-12
3.4.3 Radiation Exposure Rates B-3-12
3.5 Generic Site Parameters and Sector Summary B-3-14
3.5.1 Generic Agricultural Site B-3-14
3.5.2 Population Exposure B-3-14
3.5.3 Radionuclide Concentrations B-3-14
B.3 References B-3-R-1
B.4 FOSSIL FUELS - COAL ASH B-4-1
4.1 Introduction B-4-1
4.2 Overview of Coal Ash Generation B-4-2
4.2.1 Coal-Fired, Steam-Electric Generating Sta ions B-4-2
4.2.2 Industrial Boilers B-4-3
4.3 Coal Ash Generation B-4-3
4.3.1 Production of Coal Ash B-4-3
4.3.2 Coal Ash Disposal B-4-8
4.3.3 Coal Ash Utilization B-4-10
4.3.4 Twenty-year Coal Ash Inventory Estimate B-4-14
4.4 Radiological Properties of Coal Ash B-4-17
4.4.1 Radionuclide Concentrations B-4-17
4.4.2 Radon Flux Rates B-4-19
4.4.3 External Radiation Exposure Rates B-4-21
4.5 Coal Ash NORM Sector Summary B-4-23
4.5.1 Generic Coal Ash Disposal Site B-4-23
4.5.2 Population Exposure B-4-24
4.5.3 Radionuclide Concentrations B-4-24
B.4 References B-4-R-1
111
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TABLE OF CONTENTS
(Continued)
Chapter
Page No.
B.5 OIL AND GAS PRODUCTION SCALE B-5-1
5.1 Introduction B-5-l
5.2 Overview of Oil and Gas Production B-5-4
5.3 Oil and Gas Scale and Sludge Waste Production B-5-11
5.3.1 Origin and Nature of NORM in Oil and Gas Scale
and Sludge B-5-11
5.3.2 Oil and Gas Scale and Sludge Production Rates B-5-15
5.3.3 Oil and Gas Scale Handling and Disposal B-5-18
5.3.4 Twenty-Year Oil and Gas Scale and Sludge Volume
Estimates B-5-20
5.4 Radiological Properties of Oil and Gas Scale and Sludge B-5-21
5.4.1 Radionuclide Concentrations B-5-21
5.4.2 Radon Flux Rates B-5-24
5.4.3 External Radiation Exposures Rates B-5-24
5.5 Summary of Oil and Gas NORM Sector B-5-30
5.5.1 Generic Oil and Gas Scale Disposal Site B-5-30
5.5.2 Population Exposure B-5-30
5.5.3 Radionuclide Concentrations B-5-30
B.5 References B-5-R-1
B.6 WATER TREATMENT SLUDGES B-6-1
6.1 Introduction B-6-l
6.2 Overview of Water Supply Systems B-6-2
6.2.1 Areas of Elevated Water Radionuclide
Concentrations B-6-2
6.2.2 Water Treatment Technology B-6-5
6.3 Water Treatment Waste Generation B-6-8
6.3.1 Water Treatment Waste Generation B-6-8
6.3.2 Water Treatment Waste Disposal Methods B-6-12
6.3.3 Utilization of Water Treatment Wastes B-6-15
6.3.4 Twenty-Year Sludge Generation Estimates B-6-19
6.4 Radiological Properties of Treatment Sludge B-6-20
6.4.1 Radionuclide Concentrations B-6-20
6.4.2 Radon Flux Rates B-6-23
6.4.3 External Radiation Exposure Rates B-6-23
6.5 Generic Site Parameters and Sector Summary B-6-24
6.5.1 Generic Water Treatment Site B-6-24
6.5.2 Population Exposure B-6-25
6.5.3 Radionuclide Concentrations B-6-26
B.6 References B-6-R-1
IV
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TABLE OF CONTENTS
(Cont aued)
Chapter Page No.
B.7 METAL MINING AND PRO< ESSING WASTE B-7-1
7.1 Introduction B-7-1
7.2 Overview of the Metal R Ining Industry B-7-3
7.2.1 Metal Mining a id Waste Production B-7-3
7.2.2 Bauxite and Al minnm B-7-5
7.2.3 Copper B-7-8
7.2.4 Zinc B-7-19
7.2.5 Tin B-7-21
7.2.6 Titanium B-7-22
7.2.7 Zirconium and lafnium B-7-24
7.2.8 Ferrous Metals ;Iron and Carbon Steel) B-7-26
7.2.9 Lead B-7-33
7.3 Mineral Processing Was a Generation B-7-36
7.3.1 Mineral Proces ing Waste Production B-7-36
7.3.2 Utilization and Disposal of Bulk Waste Materials B-7-39
7.3.3 Twenty-Year ^ iste Generation Estimates B-7-41
7.4 Radiological Properties < :" Mineral Processing Wastes B-7-43
7.4.1 Radionuclide C ncentrations B-7-43
7.4.2 Radon Flux Ra as B-7-44
7.4.3 External Radia ion Exposure Rates B-7-44
7.5 Generic Site Parameters and Sector Summary B-7-46
7.5.1 Generic Miner? . Processing Waste Site B-7-46
7.5.2 Population Dis~. ibution B-7-47
7.5.3 Radionuclide C ncentrations B-7-47
B.7 References B-7-R-1
B.8 GEOTHERMAL ENERGY P '.ODUCTION WASTE B-8-1
8.1 Introduction B-8-1
8.2 Overview of the Geother nal Energy Industry B-8-3
8.2.1 Electrical Powe Production B-8-5
8.2.2 Direct Use of C jothermal Energy B-8-9
8.3 Geothermal Energy Wat .e B-8-12
8.3.1 Exploration an< Development Wastes B-8-13
8.3.2 Geothermal Po 'er Plant Wastes B-8-13
8.3.3 Waste Generat in from Direct Users B-8-14
8.3.4 Twenty-Year ^ aste Generation Estimate B-8-15
8.4 Radiological Properties < f Geothermal Energy Wastes B-8-15
8.4.1 Radionuclide C ncentrations B-8-15
8.4.2 Radon Flux fro a Geothermal Wastes B-8-17
8.4.3 External Radia ion Exposure Rates B-8-17
8.5 Summary of Geotherma Energy NORM Sector B-8-18
8.5.1 Generic Geothc mal Solid Waste Disposal Site B-8-18
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TABLE OF CONTENTS
(Continued)
Chapter Page No.
(B.5) 8.5.2 Population Exposure B-8-18
8.5.3 Radionuclide Concentrations B-8-19
B.8 References B-8-R-1
D.I RISK ASSESSMENT FOR DIFFUSE NORM D-l-1
D.I Introduction D-l-1
D.2 RISK ASSESSMENT METHODS D-2-1
2.1 The PATHRAE Dose Assessment Model D-2-1
2.2 Exposure Scenarios D-2-2
2.2.1 Worker - Direct Gamma Exposure D-2-2
2.2.2 Worker - Dust Inhalation D-2-3
2.2.3 Worker - Indoor Radon Inhalation D-2-4
2.2.4 Onsite Individual D-2-4
2.2.5 Onsite Individual Indoor Radon Inhalation D-2-5
2.2.6 Member of CPG - Direct Gamma Exposure D-2-5
2.2.7 Member of CPG - Inhalation of Contaminated
Dust D-2-6
2.2.8 Member CPG - Downwind Exposure to Radon D-2-8
2.2.9 Member of CPG - Exposure to NORM in
Building Materials D-2-10
2.2.10 Member of CPG - Ingestion of Drinking
Water from a Contaminated Well D-2-11
2.2.11 Member of CPG - Ingestion of Foodstuffs
Contaminated by Well Water D-2-13
2.2.12 Member of CPG - Ingestion of Foodstuffs
Contaminated by Dust Deposition D-2-13
2.2.13 Member of CPG - Ingestion of Foodstuffs
Grown on Repeatedly Fertilized Soil D-2-14
2.2.14 Population Downwind Exposure to
Resuspended Particulates D-2-15
2.2.15 General Population - Downwind Exposure
to Radon D-2-16
2.2.16 General Population - Ingestion of River Water
Contaminated via the Groundwater Pathway D-2-17
2.2.17 General Population -- Ingestion of River Water
Contaminated by Surface Runoff D-2-18
2.2.18 General Population - Ingestion of Foodstuffs
Grown on Repeatedly Fertilized Soil D-2-20
2.3 Input Parameters D-2-21
VI
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TABLE OF CONTENTS
(Continued)
Chapter Page No.
D.3 RISK ASSESSMENT RESULTS D-3-1
3.1 Vorker Doses and Risks D-3-1
3.2 )oses and Risks to Members of the Critical Population
Iroup (CPG) D-3-4
3.3 'opulation Doses and Risks D-3-4
3.4 Benchmarking the Dose Methodology D-3-7
3.5 Summary and Conclusions D-3-7
leferences D-R-1
E. CONC LUSIONS E-l-1
E.I Conclusions E-l-1
E.2 lecommendations E-l-6
2.2.1 Waste Volumes and Characteristics E-l-6
3.2.2 Radiological Source Term E-l-8
-].2.3 Environmental Transport Mechanisms E-l-9
£.2.4 Exposure Pathways E-l-10
i.2.5 Exposed Populations F-l-10
].2.6 Evaluation of Overall Uncertainties E-l-11
APPENDIX A: TABULATIONS OF DOSE AND RISK
CALCULATIONS TO CHAPTER D A-l
vu
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LIST OF FIGURES
Page No.
A. 1-1 Uranium decay chain A-2
A. 1-2 Thorium decay chain A-3
A. 1-3 Actinium series decay chain A-4
B.2-1 Major uraniferous phosphate deposits in the U.S. B-2-3
B.2-2 Flow diagram of phosphate material and waste production B-2-4
B.5-1 Typical production operation, showing separation of oil,
gas, and water B-5-13
B.8-1 Schematic of electric power production from a vapor-
dominated system B-8-6
B.8-2 Schematic of flashed-steam process for producing electric power
from a liquid-dominated system B-8-7
B.8-3 Schematic of binary process for producing electric power from a
liquid-dominated system B-8-8
vui
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LIST OF TABLES
Table No. Page No.
A.l-1 Exposure scenarios for diffuse NORM risk assessment A-7
B.l-1 Location of surface and underground uranium mine sites in
the U.S. B-l-3
B.l-2 Uranium ore production from 1948 to 1988 B-l-4
B.l-3 Estimated uranium mining overburden production B-l-9
B.l-4 Surface uranium mining industry based on regional reclamation B-l-14
B.2-1
B.2-2
B.2-3
B.2-4
B.2-5
B.3-1
B.3-2
B.4-1
B.4-2
B.4-3
B.4-4
B.4-5
B.4-6
Wet process phosphoric acid plants
Location and capacity of elemental phosphorus plants
Location and number of phosphogypsum stacks
Radionuclide concentrations in phosphate ores, phosphogypsum,
and slag
Summary of dose and risk results from the Idaho radionuclide
exposure study
Trends in phosphate fertilizer demand and application
Phosphate fertilizer consumption 1987-1988
Constituents of coal ash
Actual and projected yearly ash (including fly ash, bottom ash,
and boiler slag) production rate
Regional fly ash production and utilization - 1984
Ash and sludge utilization breakdown for 1987
Actual and projected yearly ash utilization rate
Estimated doses and risks from exposures to a coal ash pile
B-2-6
B-2-9
B-2-12
B-2-21
B-2-27
B-3-5
B-3-6
B-4-5
B-4-6
B-4-9
B-4-11
B-4-16
B-4-22
IX
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LIST OF TABLES
(Continued)
Table No. Page No.
B.5-1
B.5-2
B.5-3
B.5-4
B.5-5
B.5-6
B.5-7
B.6-1
B.6-2
B.6-3
B.6-4
B.6-5
B.7-1
B.7-2
B.7-3
B.7-4
B.7-5
U.S. crude oil production
U.S. natural gas production
Crude oil production for 1987 by state
Natural gas production for 1987 by state
Equipment listing and characteristics of a 10-well production
facility
Statistical analysis of radiation exposure levels associated with
NORM in oil production and gas processing equipment -
national summary
Abbreviations used to designate equipment types in oil
production and gas processing facilities
Numbers of public water systems and populations served by
sources and size category
Summary of treatment technologies for removal of naturally-
occurring radionuclides from water
Distribution of water treatment systems reported in use by
211 water utilities surveyed in 1985
Summary of water utilities operating characteristics for 1984
and 1985
Sludge disposal practices and quantities for 183 utilities in 29
selected states
Bauxite refineries
Radionuclide concentrations in alumina plant process samples
Bauxite open-pit radon surface flux rates
Primary copper processing facilities
Radionuclide concentrations in copper materials
B-5-5
B-5-6
B-5-7
B-6-9
B-5-16
B-5-25
B-5-27
B-6-6
B-6-7
B-6-9
B-6-11
B-6-13
B-7-6
B-7-9
B-7-10
B-7-12
B-7-16
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LIST OF TABLES
(Continued)
Table No. Page No.
B.7-6 Selected uranium bearing metalliferous deposits in Arizona B-7-17
B.7-7 Domestic titanium tetrachloride producers B-7-23
B.7-8 Domestic iron and steel producers B-7-27
B.7-9 Special wastes generated by ferrous metals facilities in 1988 B-7-30
B.7-10 Distribution of air-cooled iron blast furnace slag among its
various applications in 1988 B-7-31
B.7-11 Distribution of steel furnace slag among its various applications
in 1988 B-7-32
B.7-12 Primary lead processing facilities in the U.S. B-7-34
B.7-13 Estimated amount of waste generated by the mining and
beneficiation of metal ores in 1980 B-7-37
B.7-14 Estimated slag volumes generated during 1988 from processing
raw ores to produce primary metals B-7-38
B.7-15 Uses of mine waste and tailings B-7-40
B.7-16 Uses of mineral processing slag B-7-42
B.7-17 Radionuclide source term for mineral processing wastes B-7-45
B.8-1 Summary of geothermal drilling activity by state from 1981
to 1985 B-8-4
B.8-2 Geothermal plants for electricity generation B-8-10
D.l-1 Exposure scenarios for diffuse NORM risk assessment D-l-4
D.2-1 Generic input parameters for diffuse NORM risk assessment D-2-22
D.2-2 Reference disposal pile parameters and radionuclide
concentrations for diffuse NORM risk assessment D-2-24
XI
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LIST OF TABLES
(Continued)
Table No. Page No.
D.2-3 Site-specific input parameters for diffused NORM risk
assessment D-2-25
D.2-4 Dose and risk conversion factors D-2-27
D.2-5 Equivalent uptake factors D-2-30
D.3-1 Worker doses and health effects from storage or disposal of
diffuse NORM D-3-2
D.3-2 Risks from radon inhalation D-3-3
D.3-3 Individual doses and health effects from storage or disposal of
diffuse NORM D-3-5
D.3-4 Population doses and health effects from storage or disposal
D.3-5
D.3-6
D.3-7
D.3-8
D.3-9
or diffuse NORM
Benchmark of methodology for oil and gas scale/sludge
Summary of dominant risks to workers from one year of exposure
Seminary of dominant risks to the critical population group
from one year of exposure
Summary of cumulative health effects per reference site from
one year of exposure
Summary of cumulative health effects in the United States
from one vcar of exnosure
D-3-6
D-3-8
D-3-9
D-3-11
D-3-12
D-3-13
E.2-1 Sources and pathways uncertainties ranking E-l-12
XII
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EXECUTIVE SUMMARY
ES.1 INTRODUCTION
The Environmental Protection Agency (EPA), in September 1989, eleased a draft risk
assessment characterizing generation and disposal practices of wastes * lich contain diffuse
levels of naturally-occurring radioactive materials (NORM). Such v istes are typically
generated in large volumes of potentially recyclable materials v .lich may contain
radioactivity at elevated concentrations. The draft risk assessment rep rt was prepared as
an initial step in the development of acceptable standards governing the disposal and re-use
of NORM waste and material. Diffuse NORM wastes and material are of such large
volumes and relatively low radionuclide concentrations that it was deen ad inappropriate to
include them within the scope of other proposed rulemaking activitie: The draft report
indicated that there is a need to further review the data, assumptions, md models used in
that report, provide additional information on categories of diffuse NOR1 I waste which were
not explicitly addressed, and perform a more detailed risk assessment. T us report, prepared
in response to these recommendations, presents the results of further che acterization efforts
and a revised risk assessment analysis.
ES.2 WASTE VOLUME AND ACTIVITY SUMMARY
All soils and rocks are known to contain some amounts of naturally-occurring
radioactive material (NORM). The major radionuclides are uranium an< thorium, and their
respective decay products. One of the decay products is radium (Ra-22 5) and its daughter
products, which are the principal radionuclides of concern in characterize gthe redistribution
of radioactivity in the environment. Radium is normally preser ; in soil in trace
concentrations of about one picocurie per gram (pCi/g). Certain process s, however, tend to
reconcentrate or enrich the radioactivity to much higher levels in the resulting waste or
by-product material. Such processes include mining and benefication, nineral processing,
coal combustion and ash generation, and drinking water treatment, am< ng others. Some of
ES-1
-------
the NORM wastes or materials are generated in large quantities and typically are disposed
or stored at the point of generation. At times, however, NORM materials and wastes are
used in various applications which may result in unnecessary radiation exposures, potential
adverse health effects, and environmental contamination.
NORM waste generation and disposal practices are characterized in this report for
eight NORM sectors. The largest inventories of NORM waste are associated with mineral
processing, phosphate rock production, uranium mining, and coal combustion from utility and
industrial boilers. Each of these processes generates large volumes of waste with annual
production rates of several million metric tons. Over the next 20 years, these NORM sectors
will generate significant waste inventories ranging from about 1 to 20 billion metric tons.
Smaller amounts of wastes are generated by the petroleum industry (oil and gas pipe scale),
geothermal energy production, and by drinking water treatment facilities. Phosphate
fertilizers, while not a waste, are included in this analysis because of their elevated radium
concentrations. It is estimated that about 100 million metric tons of fertilizers will be applied
to agricultural fields over the next 20 years.
The following presents a summary of NORM waste generation practices, 20-year waste
or material inventories, and average Ra-226 concentrations, see Table ES-1. An overview of
each NORM sector, current waste or material generation rates, and radiological properties
is given below. Utilization practices are discussed in the next subsection.
ES.2.1 Ura""im Mining Overburden
The uranium industry currently generates about 37 million metric tons (MT) of
overburden per year, based on an average of the past four years. The total inventory of
unreclaimed overburden is estimated to be 3.1 billion MT. Much of this waste consists of soil
and rock which has been removed to uncover underlying uranium deposits. Uranium
overburden is used only in a limited number of applications, typically for backfilling mined
out areas and to construct site roads. At times, the overburden may contain low grade-ore,
which is not suitable for milling. Overburden material, even when mixed with low grade-ore,
may contain Ra-226 at relatively high concentrations, typically on the order of several tens
ES-2
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Table ES-1. 20-year NORM waste inventory and concentration8
Material or
Waste Stream
Uranium Mining
Overburden
Phosphate Waste
- Phosphogypsum
-Slag
-Scale
Phosphate Fertilizers
Coal Ash
- Fly ash
- Bottom ash and slag
Petroleum Production Scale
and Sludge
Drinking Water Treatment
- Sludges
- Radium selective resins
Mineral Processing
Geothermal Wastes
20-Year Waste
Inventory1*
740 mil. MT
800 mil. MT
(800 mil. MT)
(60 mil. MT)
(3,000 m3)
100 mil. MT
2.0 til. MT
(1.5 til. MT)
(520 mil. MT)
8.3 mil. MT
6.0 mil. MT
(5.1 mil. MT)
(840 th. MT)
20 til. MT
1.4 mil. MT
Average Ra-226
Concentration0
23.7 pCi/g
33 pCi/g
(33 pCi/g)
(35 pCi/g)
(1,000 pCi/g)
8.2 pCi/g
3.7 pCi/g
(3.9 pCi/g)
(3.1 PCi/g)
155 pCi/g
16 pCi/g
(16 pCi/g)
(35,000 pCi/g)
35 pCi/g
160 pCi/g
Addressed
in Chapter
B.I
B.2
B.3
B.4
B.5
B.6
B.7
B.8
a
See text for details and assumptions both here and in the preceding subsections.
The amounts of waste shown here only include the estimated 20-year waste inventory
and not the total inventory to date. Units are: bil., billion; mil., million; MT, metric
ton, which equals 1,000 Kg or 1.1 short ton.
Average Ra-226 concentrations are shown for comparative purposes. The risk
assessment, however, considers other radionuclides, such as uranium, thorium, and
their decay products. Concentrations shown in parentheses are included for
illustrative purposes. These values are not used in the risk assessment. See each
respective subsection for details.
ES-3
-------
of pCi/g. For the purpose of this report, the average Ra-226 concentration in overburden
waste is assumed to be 23.7 pCi/g.
ES.2.2 Phosphate Waste
It is estimated that the current inventory of phosphogypsum waste is 8 billion MT.
The yearly phosphogypsum generation rate has averaged nearly 40 million MT since 1984.
An additional 800 million MT of phosphogypsum will be added to the existing inventory over
the next 20 years. Phosphogypsum is a by-product material generated during the production
of phosphoric acid. Essentially all of the phosphogypsum is stored in waste piles, described
as stacks. Only a very small fraction of the phosphogypsum that is produced yearly is put
to use, e.g., applied as a soil conditioner. The presence of radium in phosphate rock is known
to vary from low concentrations that are nearly identical to those found in soils to levels as
high as 60 pCi/g. Elemental phosphorous plants, which use phosphate rock as feedstock,
produce a waste called slag. Slag is a vitrified waste resulting from processing phosphate
rock in high temperature furnaces. The resulting waste is also high in radium (10 to 60
pCi/g). Slag material has been used in the past as an aggregate in making roads, streets,
pavements, residential structures, and buildings. For the purpose of this report, an average
Ra-226 concentration of 33 pCi/g is assumed for both waste forms, phosphogypsum and slag.
ES.2.3 Phosphate Fertilizers
In the contest of this report, phosphate fertilizers are not assumed to be waste. The
yearly consumption of fertilizers has averaged 4.8 million MT over the past nine years. For
the purpose of this report, it is estimated that 5 million MT will be used yearly during the
next 20 years. The total amount of fertilizers applied in agricultural fields during the next
20 years is, therefore, assumed to be 100 million MT. Fertilizer application rates are known
to vary depending upon the type of crops and soils. A typical phosphate fertilizer application
rate is 40 Kg per hectare. Fertilizers are available in different blends with varying
concentrations of nitrogen, phosphate, and potassium. In fact, there are over 100 blends.
Fertilizers have varying Ra-226 concentrations (5 to 33 pCi/g) depending upon the type of
blend and origin of the phosphate rock. The average Ra-226 concentrations in fertilizers is
ES-4
-------
assumed to be 8.2 pCi/g for the purpose of this assessment. The resulting incremental
Ra-226 soil concentration is only on the order of 0.002 pCi/g for 20 years of repeated fertilizer
application.
ES.2.4 Fc
Utility and industrial boilers are estimated to generate about 60 million MT of coal
ash per year. Of this total amount, nearly 17 million MT are used in a variety of
applications. The total amount of coal ash which will be generated over the next 20 years
is estimated to be 2.0 billion MT. Coal ash is primarily being used as an additive in concrete,
as a structural fill, and for land amendment. The presence of radium in coal is known to
vary over two orders of magnitude depending upon the type of coal and region from which
it has been mined. The amount of ash generated during combustion is primarily dependent
upon the mineral content of the coal and type of boiler. Coal ash generally consists of fly ash,
bottom ash, and boiler slags. Ra-226 concentrations in coal may be as low as a fraction of
pCi/g to as high as 20 pCi/g. For the purpose of this report, the average coal ash Ra-226
concentration is assumed to be 3.7 pCi/g.
ES.2.5 Oil and Gas Production Scale and Sludge
The types of waste generated by the petroleum industry include pipe scale, sludge, and
equipment or components contaminated with Ra-226. It is estimated that the industry
generates about 360,000 cubic meters of such waste yearly. The 20-year inventory is
assumed to be 4.6 million cubic meters of 8.3 million metric tons. Field surveys have shown
that petroleum pipe scale may have very high Ra-226 concentrations, up to 40,000 pCi/g.
Some of this waste is retained in oil and gas production equipment, while some of the scale
and sludge is removed and stored in drums. The industry disposes of scale and sludge wastes
removed from oil and gas production equipment and also discards associated contaminated
components. It is difficult to estimate the volume and actual radioactivity levels of discarded
equipment since there is little or no information characterizing internal contamination levels.
The complex geometry and internal structures of such equipment makes this characterization
ES-5
-------
difficult. For the purpose of this report, it is assumed that typical scale and sludge Ra-226
concentration is 155 pCi/g.
ES.2.6
It is estimated that waste supply systems generate a yearly total of 3.1 million MT
of waste, including sludge and other waste forms as well. It is thought that about 700 water
utilities generate 260,000 MT of NORM waste yearly. The 20-year inventory is assumed to
be 6 million MT, including sludge, and spent resin and charcoal beds. Much of this waste is
disposed in landfills, lagoons, and applied in agricultural fields. Water treatment wastes are
thought to be of low Ra-226 concentrations, which may be not much different than those
found in typical soils. However, some water supply systems, primarily those relying on
groundwater sources, may generate sludge with much higher Ra-226 levels. Furthermore,
some water treatment systems are more effective than others in retaining naturally-occurring
radionuclides. For example, the highest Ra-226 concentrations are found in ion-exchange
resin beds, while lower concentrations occur in sludge from lime, soda-lime, and filtration
systems. Water supply systems which rely on ion-exchange treatment are comparatively
fewer in number. The bulk of the waste is believed to be in the form of sludge. For the
purpose of this report, it is assumed that the average Ra-226 concentrations in such waste
is 16.0 pCi/g.
ES.2.7 Metal Mining and Processing Waste
The metal mining and processing industry generates about 1 billion MT of waste
yearly, excluding phosphate and asbestos related wastes. Accordingly, the 20-year inventory
is assumed to be 20 billion MT. It has been estimated that the total waste inventory since
the turn of the century is nearly 50 billion MT. Much of this waste is stored on site or near
the point of generation. Most of the mineral processing wastes have been sued only in a
limited number of applications, typically for backfilling mined out areas and to construct site
roads. Some of the wastes, however, are in fact stockpiles which are processed several times
to extract additional minerals. Although the bulk of the waste is of low radium
concentration, about one percent, mainly from monazite sands, zircon sands, ilmenite, and
ES-6
-------
columbium, have higher radium levels. Mineral processing wastes, for metals such as lead,
iron, aluminum, and copper, generate large volumes of waste with extremely variable Ra-226
concentrations. The Ra-226 concentration assumed in this report is 35 pCi/g.
ES.2.8 Geothermal Energy Production Waste
Geothermal energy currently makes a relatively minor contribution to total U.S.
energy production. The primary geothermal development sites in the U.S. are the Geysers,
in Sonoma County in northern California, and the Imperial Valley in southern California.
The only significant NORM-contaminated wastes from geothermal power production are the
solid wastes originating from the treatment of spent brines. Very limited data exists from
which to characterize the volumes and radionuclide concentrations of these wastes. The
vapor resources at the Geysers are characterized by a very low dissolved solids content.
However, the hot saline fluids from Imperial Valley reservoirs may have a dissolved solids
content approaching 30 wt percent. For this assessment, the estimated NORM waste
volumes and radionuclide concentrations are based on limited information available
characterizing Imperial Valley geothermal wastes. The estimated 20-year waste volume for
this NORM section is 800,000 m3 or 1.4 million MT. The estimated average Ra-226
concentration in this waste is 160 pCi/g.
ES.3 PAST AND CURRENT PRACTICES AND EXPOSURE POTENTIAL
There have been a number of cases where the improper disposal of NORM wastes has
resulted in increased levels of direct gamma exposure to individuals. In Montclair, New
Jersey, radium contaminated soil caused higher than normal direct gamma radiation
exposure levels. The use of elemental phosphorus slag to construct roads in Pocatello, Idaho
has resulted in a doubling of the natural background radiation levels in some areas. In
Mississippi, the use of pipes contaminated with radium scale in playgrounds and welding
classes has resulted in some unnecessary radiation exposures to students using that
equipment.
ES-7
-------
Several forms of diffuse NORM wastes are being disposed or used in a variety of
manners. Phosphate waste is placed in large stacks where they are produced, with some of
the waste subsequently being used for agricultural or construction purposes. In the past,
homes have been built over land containing phosphogypsum waste. Uranium mining
overburden is piled and stabilized where it is mined, with Uttle or no subsequent use.
Coal ash is placed in on-site storage ponds, surface impoundments, and sanitary
landfills, as well as being reused in road construction, embankments, and in cement
aggregates. Studies are currently taking place on the potential use of fly ash in wallboard
which may be used in residential and commercial structures. Water treatment plant residues
are placed in ponds, sanitary landfills, or spread on agricultural soils. Phosphate fertilizers
are, of course, spread on agricultural lands.
Mineral processing wastes are generally disposed in tailings ponds or used to construct
dams, dikes, or embankments. Small amounts of waste have been used offsite for backfill,
aggregate production, or for road building. Some mineral processing wastes have been used
to make wallboard and concrete. Oil and gas pipe scale from the petroleum industry, which
is being studies at greater length, is mostly stored until a proper disposal method can be
identified. In past practices, however, much of the oil and gas scale has been dumped into
nearby surface waters or collection ponds. Some radium contaminated piping has been
donated to schools or other organizations.
The contamination of groundwater from NORM wastes has occurred in a few
instances. In most cases, however, radium is relatively immobile and does not move into
groundwater very quickly. An exception to this may be mineral processing wastes containing
radium in the chloride form, which appears to have a much higher mobility. In the past,
groundwater contamination has been associated with uranium mining waste and from the
improper disposal of radium pipe scale.
Many of these disposal methods or uses may result in negligible exposures to
individuals. However, improper use or disposal of these wastes can result in significant
contamination of the environment, as well as having adverse impacts on individual and
public health. In fact, the unregulated use or disposal of waste containing elevated
concentrations of radium has resulted in contamination of soil and groundwater, and
ES-8
-------
exposures to individuals. In addition, as waste materials are being used, further research
is taking place to identify new applications, in turn possibly leading to additional individual
exposures.
ES.4 RISK ASSESSMENT ANALYSES
The risk assessment analysis addresses several pathways for exposures to disposal site
workers, members of the critical population group (CPG), and the general population for each
of the eight NORM waste sectors. The exposure scenarios evaluated for each NORM sector
are shown in Table ES-2.
Estimated dominant risks to workers at NORM storage and disposal sites and to
members of the CPG are summarized in Table ES-3. For site workers the dominant exposure
pathway is indoor radon inhalation to office workers. For office workers, the 70-year lifetime
risks from one year of radon inhalation are estimated to range from 9.3E-02 for the
geothermal waste sector to 1.2E-04 for landfill disposal of water treatment sludge. For
exposure pathways other than radon inhalation, the dominant health risks result from direct
gamma exposure of disposal pile workers. Risks from direct gamma exposure are estimated
to be two or three orders of magnitude smaller than risks from indoor radon inhalation.
Seventy-year lifetime risks from direct gamma exposure range from 2.5E-04 for the oil and
gas scale/sludge NORM sector to 2.4E-09 for workers on fields repeatedly fertilized with
phosphate fertilizer.
Indoor exposure to radon gas by a person living on an abandoned NORM disposal site
is estimated to be the dominant exposure pathway for members of the CPG. For this
pathway, the 70-year lifetime risks from one year of exposure to indoor radon range from
3.1E-01 for the geothermal waste sector to 3.0E-06 for a field repeatedly fertilized with
phosphate fertilizer. For exposure pathways other than radon inhalation the dominant CPG
health risks are from direct gamma exposure, either to a person who lives on an abandoned
disposal site or to a person exposed to NORM in building materials. For direct gamma
exposure, the 70-year lifetime risks from one year of exposure range from 6.7E-03 for mineral
processing waste to 1.1E-08 for a field repeatedly fertilized with phosphate fertilizer. For
ES-9
-------
Table E8-2. Exposure aceoarloa for dlffuM NORM risk aeeeesment.
Exposure Scenario
Worker
Direct Gamma Eipoaure
Dual Inhalation
Indoor Radon Inhalation
Onalte Individual
Direct Gamma Exposure
Indoor Radon Inhalation
Member of CPC
Direct Gamma Exposure
Inhalation of Contaminated Dust
Downwind Exposure to Radon
NORM in Building Material!
Ingestion of Drinking Water from a
Contaminated Well
Ingest ion of Foodslufls Contaminated
by Well Water
Ingestion of Foodstuff* Contaminated
by Dust Deposition
Ingestion of Foodatufla Grown on
Repeatedly Fertilized Sal
Uranium
Overburden
X
X
X
X
X
X
X
X
X
X
X
Pboepbate
Waste
X
X
X
X
X
X
X
X
X
X
X
X
Phoepbate
Fertlllier
X
X
X
X
X
X
X
X
X
X
X
CoalAah
X
X
X
X
X
X
X
X
X
X
X
X
Water
Treatment
Sludge -
Fertiliser
X
X
X
X
X
X
X
X
X
X
X
Water
Treatment
Sludge -
Landfill
X
X
X
X
X
X
X
X
X
X
X
Mineral
Proceailng
Waale
X
X
X
X
X
X
X
X
X
X
X
X
Oil * Gaa
Bcale/Bludaja
X
X
X
X
X
X
X
X
X
X
X
Geo thermal
Waste
X
X
X
X
X
X
X
X
X
X
X
General Population Near Sites
Downwind Exposure to Resuspendcd
Particulates
Downwind Exposure to Radon
Ingestion of River Water
Contaminated Via the Groundwater
Pathway
Ingestion of River Water
Contaminated by Surface Runoff
Ingealion of Foodstufls Grown on
Repeatedly Fertilized Sal
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
Table ES-3. Summary of dominant risks to individuals from storage of disposal of diffuse
NORM wastes.
Fertilizer
Water Treatment Sludge -
Landfill
Mineral Processing Waste
Oil and Gas Scale/Sludge
Geothermal Waste
Disposal Site Worker
(Health Effects)*
Member of CPG
(Health Effects)"
NORM Waste
Sector
Uranium Overburden
Phosphate Waste
Phosphate Fertilizer
Coal Ash
Water Treatment Sludge -
Exposure Pathways
Except Radon
Inhalation
2.5E-06
3.SE-05
2.4E-09
6.3E-06
a8E-07
Radon
Tnlialation
1.8E-02
1.2E-02
1.4E-04
_
Exposure Pathways
Except Radon
Inhalation
1.1E-04
4.4E-03
1.1E-08
7.3E-04
4.0E-06
Radon
Inhalation
6.0E-02
3.9E-02
3.0E-06
4.5E-04
l.OE-03
3.1E-07
5.9E-05
2.5E-04
2.6E-05
1.2E-04
2.7E-02
2.1E-02
9.3E-02
1.4E-06
6.7E-O3
1.2E-03
1.2E-04
3.8E-04
8.9E-02
7.0E-02
3.1E-01
The 70-year lifetime risk of a fatal cancer from one year of exposure.
ES-11
-------
members of the CPG, health risks from direct gamma exposure are estimated to be one to
three orders of magnitude smaller than health risk from indoor radon inhalation.
Estimated population health effects (e.g., cumulative health effects to persons living
and working offsite) are summarized in Table ES-4. The largest number of cumulative health
is associated with the coal ash NORM sector, in part because of the large number of sites
needed to deplete the 20-year inventory. Two NORM sectors - coal ash and mineral
processing waste - have total population health effects greater than unity. The NORM
sectors with the lowest total population health effects - water treatment sludge, oil and gas
scale/sludge, and geothermal waste - each have less than 0.1 health effects from one year of
exposure.
The risk assessment results suggest that a relatively moderate number of health
effects could result from the improper use or disposal of diffuse NORM wastes. These results
are based only on the total NORM waste inventory anticipated to be generated over the next
20 years. Should the total inventory of NORM waste accumulated to date to used instead,
the total number of health effects would increase significantly. However, this assumption
would most likely be unrealistic because the accumulated waste inventory is not in a readily
accessible an useable form, as postulated in this report, and currently there is no outlet
which would allow that much NORM waste to be recycled.
Given the uncertainties associated with waste volumes, radionuclide concentrations,
and exposure pathway models and parameters, it is estimated that the results of this risk
assessment analysis are within a factor of 3 of results that might be obtained by using more
sophisticated computer codes. In general, it is suspected that the variability of the results
is asymmetric, in the sense that the degree of conservatism is more pronounced on the lower
range of the input parameters and assumptions than on the higher end. Accordingly,
depending upon a specific input parameter or assumption, the results may reveal a still
greater degree of variability. Finally, it should be noted that changing a parameter does not
always yield results that are directly proportional since competing factors may nullify an
increase in a specific parameter.
Given that these results are based on a number of assumptions, some better defined
than others, these estimates are still uncertain. The results imply, however, that the number
ES-12
-------
Table ES-4. Summary of population health affects from storage or disposal of
diffuse NORM wastes.
Number of Health Effects*
NORM Waste
Sector
Uranium Overburden
Phosphate Waste
Phosphate Fertilizer
Coal Ash
Water Treatment Sludge -
Number of Sites
for 20-vear Inventc -v_
1.4E+01
1.5E+01
9.4E+05
1.3E+03
4.4E+02
Generic
Site
1.7E-02
3.5E-02
9.8E-07
8.9E-03
1.6E-04
Nationwide for
20-year Inventory
2.4E-01
5.2E-01
9.2E-01
1.2E+01
7.0E-02
Fertilizer
Water Treatment Sludge -
Landfill
Mineral Processing Waste
Oil and Gas Scale/Sludge
Geothermal Waste
2.3E+02
6.7E+02
l.OE+01
2.0E+00
7.9E-06
2.6E-03
5.6E-03
7.6E-03
1.8E-03
1.7E+00
5.6E-02
1.5E-02
Number of excess fatal cancers (70-year lifetime r ,k) expected in the exposed population as a result
of one year of exposure.
ES-13
-------
of potential health effects may be significant enough to warrant additional evaluation of
NORM waste generation and disposal practices for some of the NORM waste sectors.
ES.5 REGULATORY CONTROL OPTIONS
The Atomic Energy Act of 1954, and subsequent amendments, is the basic framework
for the regulatory control of radioactivity and radioactive material. The Act of 1954 and
administrative reorganizations, give the primary regulatory responsibility to the U.S. Nuclear
Regulatory Commission (NRG). The NRC has granted some of these responsibilities to states,
under the Agreement State Program. The states, in addition to the responsibilities granted
by the NRC, have in some cases adopted additional regulations. In addition to the
regulations of the NRC and agreement states, several federal agencies (e.g., Department of
Transportation, Department of Labor, and Environmental Protection Agency) have regulatory
authority related to pertinent aspects of radiation, radiation protection for workers, and
radioactive materials shipment and disposal.
NORM materials are not covered by the Atomic Energy Act of 1954 and are generally
not specifically covered by most existing regulations. Although they are covered by some
state regulations, there are presently no universally applicable regulations for NORM
materials. The Conference of Radiation Control Program Directors (CRCPD) has prepared
draft regulations to be considered by the states. These draft regulations specify criteria in
terms of concentration and surface contamination limits.
Some states have taken the lead and are in the process of drafting regulations to
address specific problems. For example, the State of Louisiana has promulgated emergency
regulations, similar to the draft regulations of the CRCPD in 1989. The Louisiana
regulations identify the criteria for unrestricted release as surface contamination criteria
similar to the American National Standards Institute recommendations. The State of Texas
has issued an interim policy regarding the handling and disposal of contaminated oil and gas
pipe scale and equipment.
ES-14
-------
The improper use or disposal of diffuse NORM wastes has led to circumstances
resulting in contamination events and unnecessary exposures. Such events have included
groundwater contamination, direct radiation exposures to individuals, and increased levels
of radon gas in homes built over contaminated materials. In view of the results of the risk
assessment, it c»" be seen that there exists a range of potential health impacts associated
with the improper use or disposal of NORM wastes. It is clear that a significant number of
health effects and high risks could occur for a limited number of individuals in exposed
populations. There is still some uncertainty about many of the assumptions used in the
analyses. Even with these uncertainties, however, such occurrences suggest that the disposal
of large quantities of diffuse NORM waste may warrant the implementation of some
regulatory controls.
One option for regulating the disposal of NORM wastes would be the use of RCRA.
Based on the potential health impact associated with radium-226, NORM waste could be
designated as a RCRA hazardous waste. As this would require disposal in RCRA hazardous
waste disposal facilities, this may not be a particularly feasible option due to the tremendous
volumes of NORM waste being generated.
Another option, under RCRA, would be to use Subtitle D requirements for regulating
disposal. This option is being studies by EPA, although with no regulatory action planned
at this time. In addition, use of Subtitle D is less desirable, since Subtitle D lacks federal
enforcement capabilities.
There is a drawback in using RCRA in that RCRA only governs waste disposal. Since
much of the health impact is due to the improper use of NORM waste, RCRA could not be
used to control that aspect since it would be considered recycling and not waste disposal. For
this reason, and because of the lack of past regulatory action for this class of waste under
RCRa, it is appropriate to consider other regulatory options.
There are currently EPA regulations being considered which apply to the disposal of
higher concentrations of NORM wastes (greater than 2,000 pCi/g). The diffuse NORM
wastes, however, are of such large volume and relatively low radionuclide concentrations that
it was deemed inappropriate to include these wastes within the scope of the rulemaking.
These regulations are being prepared under the authority of Section 6 of TSCA, which could
ES-15
-------
also be used to regulate diffuse NORM wastes. Under Section 6, materials found to present
unreas >nable risk to the public can be controlled in a variety of ways, including requirements
on dis osal, manufacture, distribution in commerce, and the use of warning labels and
record eeping.
Since the greatest health impact associated with diffuse NORM wastes appears to be
assoti: .ed with its improper use and disposal, Section 6 of TSCA would allow the EPA to
probib . certain uses of the waste that were found to be improper, such as its use as fill
materi 1 or incorporated in wallboard or other types of construction materials. Section 6
could: so be used to regulate the disposal of the waste if it were determined to be necessary
for pul ic health reasons. In addition to the control options available under Section 6, other
sectior ; of TSCA allow the Administrator to designate other federal agencies to help in
impler anting and enforcing the regulations, if it is found that this approach is the most
efficiei o way to regulate NORM waste, while placing the least burdensome requirements on
waste enerators. Because of the inherent flexibility of the TSCA regulations, this approach
may bt the optimal was to establish the proper regulatory controls for the use and/or disposal
or NO M waste.
ES-16
-------
A. INTRODUCTION
Radi active materials ca: be classified under two broad headings: man-made and
naturally-oi urring radioactive B aterials. Man-made radionuclides are produced by splitting
atoms in m lear reactors or by 1 >mbarding atoms with subatomic particles in accelerators.
Examples < man-made radion elides include cobalt-60, strontium-90, and cesium-137.
Naturally-o oirring radionuclide include primordial radionuclides that are naturally present
in the rock and minerals of th» earth's crust and cosomogenic radionuclides produced by
interactions of cosmic nucleons with target atoms in the atmosphere and in the earth.
Example of osomogenic radioni .lides include carbon-14 and tritium (hydrogen-3).
The rintipal primordial i idionuclides are isotopes of heavy elements belonging to the
radioactive eries headed by th three long-lived isotopes uranium-238 (uranium series),
xiranium-2c (actinium series), i id thorium-232 (thorium series). These three decay series
are shown i Figures A.l-1 to A -3. All three of these series have numerous radionuclides
in their dec. / chains before read ing a stable end point, lead. At background concentrations,
the natural] -occurring radionuci des in the uranium, actinium, and thorium series contribute
about one-} df of the natural b ckground external radiation, and over 80 percent of the
background ncluding radon, to bich all humans are continuously exposed.
NOf Jl (naturally-occurr ig radioactive material) consists of material containing
isotopes bel aging to the uraniui , actinium, and thorium series. The principal radionuclide
of concern NORM is radium- 26, a member of the uranium series, which is present in
natural soi in concentrations f about 1 pCi/g. However, NORM radioisotopes may be
present in c Dferent materials in /arying concentrations, and some NORM wastes may have
radium-226 concentrations that are much higher than 1 pCi/g, and may be as high as
hundreds o thousands of pCi/g.
The Jtimate sources of -he primordial radionuclides in the environment are the
earth's cms and its underlying ] Lastic mantle. Movement of material or heat, or both, from
the mantle to the crust, and 1 3at from radioactive decay in the crust, have caused a
reorganizat >n of the chemical ilements in the crust tending from homogeneity toward
A-l
-------
£
URANIUM-23B
THORIUM-234*
24 d
>
PROTACTINIUM (m)-234*
l.i/m
URANIUM-234
SHORT HALF-LIFE
RADON DECAY PRODUCTS
NOIE
Verified DlrecHon Represents Alpha Decay,
Horizontal Direction Indicates Beta Decay.
Times Shown are Half-Live*. Only the
Dominant Decay Mode Is Shown.
Also Gamma Emitters, the Gamma Emissions
from the Other Isotopes are Insignificant
THORIUM-230
Y7.7E+04y
RADIUM-226*
y 1.6E+03y
RADON-222
1
3.82d
3.05m
26.8m
5.0 d
V^r^^^^^^^^^^^^^^d '^^^Jt^^JLJ^^^JL
\
138 4 d
r
LEAD-206
(STABLE)
19.9m
22.3 y
LONG HALF-LIFE
RADON DECAY PRODUCTS
RAE-102794
l.6E-04s
l
Figure A.l-1. Uranium decay chain.
-------
THORIUM-232
|l40SE»IOy
RADIUM-228
ACTINIUM-228'
N01E:
Vertical Direction Represents Alpha Decay,
Horliontal Direction Indicate* Beta Decay.
Time* Shown are Half-Lives. Only the
Dominant Decay Mode Is Shown.
* Also Gamma Emitters, Ihe Gamma Emissions
from Ihe Other Isotopes are Insignificant
THORIUM-228*
1.91 y
J362d
RADON-220
55.6s
|oi46s
RADIUM-224*
POLONIUM-216
10.64 h
60.6m
64%
>
POLONIUM-212
36%
0.3 ps
THALLIUM-206*
LEAD-208
(STABLE)
RAE-I0279SA
Figure A.l-2. Thorium decay chain.
-------
URANIUM-235
y7.0E+08y
THORIUM-231
zon
^
PROTACTINIUM-231
y 3.3E+04y
ACTINIUM-227
zzy
THORIUM-227
NOTE:
Nfertical Direction Represents Alpha Decay,
Horizontal Direction Indicates Beta Decay.
Times Shown are Half-Uves. Only the
Dominant Decay Mode Is Shown.
18.70
RADIUM-223
y n
.4d
RADON-219
I
4.0s
POLONIUM-215
LEAD-211
jom
>.
BISMUTH-211
1 2.1m
THALLIUM-207
4.8m
>>
LEAD-207
(Stable)
RAE-103S27
Figure A.l-3. Actinium series decay chain.
-------
heterogeneity. Redistribution has also occurred as a result of weathering and sedimentation.
As a consequence of these processes, the uranium and thorium series nuclides have tended
to concentrate in certain minerals and certain geologic formations. For example, uranium
in significantly elevated concentrations is associated with' phosphate ores in three major
locations in the U.S. These locations are southeastern Idaho And parts of neighboring states,
central Florida, and central Tennessee and northern Alabama. Radionuclides from the
uranium and thorium series are also associated in widely ranging proportions in the crude
oil and brine extracted from underground petroleum reservoirs.
NORM wastes are the radioactive residues from the extraction and purification of
minerals, petroleum products, or other substances obtained from parent materials that may
contain elevated concentrations of primordial radionuclides. Each year, hundreds of millions
of metric tons of NORM waste are generated from a wide variety of processes, ranging from
uranium and phosphate mining to municipal drinking water treatment. Processes that
produce NORM wastes analyzed in this study include uranium mining, phosphate and
elemental phosphorus production, phosphate fertilizer production, coal ash generation, oil and
gas production, drinking water treatment, metal mining and processing, and geothermal
energy production. During mining and beneficiation, mineral processing, oil and gas
extraction, or various other processes, primordial radionuclides present in the parent
materials can become concentrated in the wastes. This results in radionuclide concentrations
in NORM wastes that are often orders of magnitude higher than in the parent materials.
The exposure to individuals from NORM wastes occurs in three main ways. The first
is associated with the normal disposal of the waste in piles or stacks. This type of disposal
can lead to groundwater contamination and to airborne releases of radioactive particulates
and radon. The second is from the improper use and/or disposal of these wastes, such as for
soil conditioning or fill dirt around homes. This can lead to build-up of radon gas in homes,
direct exposure to individuals located nearby, contamination of soil and the crops growing in
that soil, and groundwater contamination. The third way is the improper use of NORM
waste in materials, such as concrete aggregate and wallboard. This can lead to direct
external exposures to individuals and to increased levels of radon in homes.
A-5
-------
Most radionuclides are regulated under the authority of the Atomic Energy Act (AEA).
The AEA, however, excludes all NORM, except high grade uranium and thorium ore, any
materials containing uranium and thorium, and uranium mill tailings. The Environmental
Protection Agency (EPA) is currently developing regulations for the disposal of higher
concentration (above 2 nanocuries/gram) NARM (naturally-occurring and accelerator-produced
radioactive materials) wastes under the authority of the Toxic Substances Control Act (TSCA)
(EPA88). For the lower concentration materials, termed diffuse NORM wastes, no federal
regulations currently exist. Due to the large volumes of diffuse NORM wastes that are
generated each year, and the potential risk of individual exposures associated with the
improper use and disposal of these wastes, it is appropriate for the EPA to consider
developing controls on the use and disposal of diffuse NORM wastes.
The EPA, in September 1989, released a draft risk assessment characterizing
generation and disposal practices of diffuse NORM wastes. The draft risk assessment report
was prepared as an initial step in the development of acceptable standards governing the
disposal and re-use of NORM waste and material. The draft report indicated that there is
a need to further review the data, assumptions, and models used in that report, provide
additional information on categories of diffuse NORM waste which were not explicitly
addressed, and perform a more detailed risk assessment. This report, prepared in response
to these recommendations, presents the results of further characterization efforts and a
revised risk assessment analysis.
In the following chapters, the major waste generating processes for eight NORM waste
sectors are described and the radioactivity concentrations and volumes of these wastes are
estimated. Also discussed are current practices for the wastes, regarding their use and
disposal. A risk assessment is performed which addresses several pathways for exposures
to individuals and the general population for each of the eight NORM waste sectors. The
exposure pathways considered include direct gamma radiation, dust inhalation, downwind
dispersion of resuspended particulates and radon, indoor radon inhalation, exposure from
building materials that incorporate NORM waste, and ingestion of contaminated water and
foodstuffs. The NORM waste sectors analyzed and the exposure scenarios evaluated for each
sector are shown in Table A. 1-1.
A-6
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Table A.M. Exposure scenario* for diffuse NORM risk
Worker
Direct Gamma Exposure
Dust Inhalation
Indoor Radon Inhalation
Onalte Individual
Direct Gamma Exposure
Indoor Radon Inhalation
Member of CPG
Direct Gamma Exposure
Inhalation of Contaminated Dual
Downwind Exposure to Radon
NORM in Building Materials
Ingealion of Drinking Water from a
Contaminated Well
Ingeation of Foodslufls Contaminated
by Well Water
Ingestion of Foodstuda Contaminated
by Dust Deposition
Ingestion of Foodstuffs Grown on
Repeatedly Fertiliied Soil
Uranium
Overburden
X
X
X
X
X
X
X
X
X
X
X
Phosphate
Waste
X
X
X
X
X
X
X
X
X
X
X
X
Phosphate
Fertlllier
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Water
Treatment
Sludge -
Fertilizer
X
X
X
X
X
X
X
X
X
X
X
Water
Treatment
Sludge -
Landfill
X
X
X
X
X
X
X
X
X
X
X
Mineral
Proceeding
Waato
X
X
X
X
X
X
X
X
X
X
X
X
Oil * Oaa
Scale/Sludge
X
X
X
X
X
X
X
X
X
X
X
G«o thermal
Waato
X
X
X
X
X
X
X
X
X
X
X
General Population Near Bites
Downwind Exposure to Resuspcndcd
Particulatea
Downwind Exposure to Radon
Ingestion of River Water
Contaminated Via the Ground water
Pathway
Ingestion of River Water
Contaminated by Surface Runoff
Ingestion of Foodstufls Grown on
Repeatedly Fertilized Sal
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
Risks from exposure to NORM waste are evaluated for site workers, onsite individuals,
members of the critical population group (CPG), and the general population. These exposed
persons are identified and described in the following paragraphs.
y
Site workers include disposal pile workers and office workers. The disposal pile
worker is an adult employee who works 2,000 hours per year, spending 80 percent of his time
on the waste pile. It is assumed that the waste pile is not covered or capped. The worker
uses machinery such as a grader or bulldozer which places him one meter above the pile
surface and provides some shielding from direct gamma radiation. Exposure pathways for
the disposal pile worker include direct radiation and dust inhalation. For direct radiation,
a shielding factor of 0.6 is applied to account for the shielding provided by the machinery
used by the worker.
The office worker also works 2,000 hours per year in a building located at the disposal
site. While in the building, the worker is exposed via the indoor radon inhalation pathway.
Although an office building would likely be located at some distance from the disposal pile,
to estimate the indoor radon concentration it is assumed that the building is located on the
pile. This results in a conservatively high estimate of the radon exposure received by the
office worker.
Two exposure pathways are evaluated for a person who is assumed to live on a site
which was formerly used for the disposal of diffuse NORM wastes. The exposure pathways
analyzed for this "onsite individual" are indoor radon inhalation and direct exposure to
gamma radiation. For indoor exposure to radon, the exposure fraction (i.e., the fraction of
a year that the person is exposed) is 0.75. For direct exposure to gamma radiation, the
equivalent exposure fraction is 0.5. This equivalent exposure fraction takes into
consideration the time spent outside plus the time spent inside at a reduced exposure level.
Several exposure pathways are evaluated for a member of the CPG. This person is
assumed to be an adult who lives in a house located 100 m from the disposal pile. The
person obtains all of his water from a well adjacent to the house. Fifty percent of his
foodstuffs are assumed to be grown onsite. For a member of the CPG, the exposure pathways
analyzed include direct radiation, inhalation of contaminated dust, downwind exposure to
radon, exposure to NORM in building materials, ingestion of contaminated well water,
A-8
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ingestion of foodstuffs contaminated by well water, ingestion of foodstuffs contaminated by
dust deposition, and ingestion of foodstuffs grown on repeatedly fertilized soil. For direct
exposure to gamma radiation, contaminated dust inhalation, and downwind exposure to
radon, the equivalent exposure fraction is 0.50. This equivalent exposure fraction takes
account of the time spent outside plus the time spent indoors at a reduced exposure level.
Several exposure pathways are evaluated for the general population residing near the
disposal sites. Population exposure pathways include downwind exposure to resuspended
particulates, downwind exposure to radon, ingestion of river water contaminated by
groundwater or by surface runoff, and ingestion of foodstuffs grown on repeatedly fertilized
soil. For the downwind exposure pathways, the exposed population is assumed to reside
within a radius of 80,000 m (50 mi) of the disposal site. For the ingestion pathways the
exposed population is assumed to live within a river water "use area" of approximately
1,000 mi2.
This report presents a waste characterization and risk assessment for diffuse NORM
waste. Chapter B presents the major NORM waste generating sectors and a description of
the processes which result in the generation of such wastes. The characterization provides
a description of the physical and radiological properties of the waste, waste generation rates,
and a 20-year inventory. Also reviewed are current industry or NORM sector practices
regarding the use and disposal of such wastes. An overview of past disposal practices and
misuse of NORM waste is provided in Chapter C. The risk assessment, presented in Chapter
D, focuses on the health impact associated with the uncontrolled disposal and/or use of these
wastes. The risk assessment estimates are calculated to provide an insight into the potential
health impact associated with NORM waste, to determine whether a more rigorous analysis
or more detailed characterization is justified, and to help evaluate the need for future
regulatory action. Chapter E provides a summary and conclusion.
A-9
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CHAPTER A
EPA88 U.S. Environmental Protection Agency, "Low-Le -el and NARM Radioactive
Wastes, Draft Environmental Impact Statement or Proposed Rules, Volume
1, Background Information Document," EPA 520/ L-87-012-1, June 1988.
A-R-1
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B.I. URANIUM MINING OVERBURDEN
1.1 INTRODUCTION
The uranium mining industry began in the late 1940s primaril; for the purpose of
producing uranium ore for use in weapons production and nuclear fu< I fabrication. The
mining of uranium ore by both underground and surface methods prod ces large amounts
of bulk material, including excavated topsoil, overburden, low grade ore and mining spoils.
Topsoil is the natural soil overlying the area which is being mined. O jrburden, which is
beneath the topsoil and overlies the ore deposit, contains limited amounts rf natural uranium
and its progeny. Overburden materials must be removed in order to ex. ose the underlying
ore bodies. Low grade ore material, or subore, contains significant amou its of uranium, but
usually does not have a high enough uranium concentration to make n Jling economically
feasible. Mining spoils include low grade ore and other materials exc: /ated during mine
exploitation. The quantities of these materials produced during minir j depend upon the
mining method used and the ore grade. The ore grade is known to vary )y type of uranium
deposits and mining regions. For example, the ore mined from 1978 to 1987 was reported
to have a U308 concentration that varied Scorn a low of 0.112 percent to a high of 0.336
percent, with an average of 0.162 percent (DOE88, EIA88a).
Waste piles are associated with the larger mines, and surface mi ies are responsible
for the vast majority of the waste materials. The potential for the \i iste piles to cause
exposure to the general public or to become redistributed in the envin iment depends, in
part, on their location and whether they have been stabilized.
In the sections that follow, a description is provided of the uraniu a mining industry,
the properties of uranium overburden materials, and actual and pr jected amounts of
overburden waste materials produced by this NORM sector. This inf< rmation is used to
assess potential exposures to the members of the general public and critic: 1 population group,
see Chapter D.
B-l-1
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1.2 OVERVIEW OF THTC TTRAEflUM MINING INDUSTRY
There are 3,592 surface and underground uranium mines located in 18 states in the
United States, but only a small number of these are currently operating (EPA83). A
summary of the number of surface and underground mines that have produced ore since the
inception of the industry is presented in Table B.l-1.
The production of uranium ore by surface and underground mining methods has been
on a steady decline since 1980, when the average contract price of U308 decreased from $40
to $26 per pound (EIA88a). In 1982 there were 139 underground mines and 24 surface mines
still operating in the United States; currently, only 15 underground mines and two surface
mines are in operation (EPA89). Most of the inactive mines (about two-thirds) are surface
mines which, to date, have produced over 99 percent of the waste material. Because of the
sharp decline in uranium mining and the shift from surface to underground mines in the
decade of the 1980s compared to the previous decade, projections of uranium ore production
and the associated waste volumes bear little resemblance to the past experience of the
uranium mining industry. In addition, the current inventory of unreclaimed mining
overburden is projected to decrease as planned reclamation is performed (SCA89).
A summary of uranium ore and U30o production by the uranium mining industry in
the U.S. is presented in Table B.l-2. The production of uranium ore peaked in 1980 when
a total of 15.2 million MT of ore, including 9.4 million MT from surface mines and 5.8
million MT from underground mines, was produced. By 1988, uranium ore production had
decreased to 1.1 million MT, including 0.63 million MT from surface mines and 0.47 million
MT from underground mines (EIA88a).
1.2.1 Surface
The use of surface (open pit) mining methods is most prevalent in Wyoming, New
Mexico, south Texas, and in some areas of Colorado and Utah. In surface mining, an open
pit is excavated to expose the uranium deposit. After the topsoil is removed and stockpiled
nearby, the overburden is removed by the method best suited to the nature of the rock. If
B-l-2
-------
Table B.l-1. Location of surface and underground uranium mine sites in the U.S.8
State
Alaska
Arizona
California
Colorado
Idaho
Minnesota
Montana
Nevada
New Jersey
New Mexico
North Dakota
Oklahoma
Oregon
South Dakota
Texas
Utah
Washington
Wyoming
Subtotal:
Total:
Surface
0
135
13
268
2
0
9
9
0
38
13
3
2
111
54
391
15
242
1,305
Underground
1
190
10
1,008
4
0
9
12
1
177
0
0
1
30
0
806
0
38
2,287
3,592
a
Table adapted from data taken from EPA83.
B-l-3
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Table B.l-2. Uranium ore production from 1948 to 1988.a
Year
1948°
1949d
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
Surface
Ore
(MT)
<9.0E+2
9.1E+2
2.1E+4
2.5E+4
5.9E+4
1.6E+5
2.4E+5
3.4E+5
1.1E+6
1.5E+6
2.1E+6
2.0E+6
2.2E+6
2.3E+6
1.6E+6
1.7E+6
1.4E+6
1.1E+6
1.2E+6
1.4E+6
2.1E+6
2.0E+6
2.5E+6
3.0E+6
3.5E+6
4.1E+6
3.8E+6
3.9E+6
4.2E+6
Mines*
(MT)
0.1E+1
<9.1E+1
9.1E+1
1.8E+2
2.7E+2
5.4E+2
8.2E+2
7.3E+2
2.9E+3
3.1E+3
4.9E+3
4.0E+3
4.8E+3
4.8E+3
3.9E+3
4.0E+3
3.1E+3
2.7E+3
2.8E+3
2.9E+3
4.2E+3
4.7E+3
5.4E+3
6.4E+3
7.4E+3
7.8E-1.3
6.6E+3
6.1E+3
6.2E+3
Undereround
Ore
(MT)
3.4E+4
1.6E+5
2.1E+5
2.9E+5
3.4E+5
5.0E+5
7.6E+5
l.OE+6
1.6E+6
1.9E+6
2.6E+6
4.3E+6
5.1E+6
5.0E+6
4.8E+6
3.7E+6
3.4E+6
2.8E+6
2.7E+6
3.4E+6
3.7E+6
3.4E+6
3.2E+6
2.7E+6
2.3E+6
1.8E+6
2.6E+6
2.5E+6
3.6E+6
Mines*
U308
(MT)
9.1E+1
4.5E+2
6.4E+2
8.2E+2
9.1E+2
1.5E+3
2.4E+3
3.3E+3
4.7E+3
5.8E+3
7.8E+3
1.2E+4
1.2E+4
1.2E+4
1.2E+4
9.4E+3
9.5E+3
6.7E+3
6.2E+3
6.8E+3
7.3E+3
6.4E+3
6.3E+3
5.4E+3
5.1E+3
4.5E+3
4.6E+3
4.8E+3
6.1E+3
B-l-4
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Table B.l-2. Continued.
Surface Mines1* Underground Minesb
Ore U308 Ore U308
Year (MT) (MT) (MT) (MT)
1977 5.1E+6 6.9E+3 4.3E+6 7.5E+3
1978 7.5E+6 8.7E+3 5.5E+6 8.4E+3
1979 8.8E+6 8.5E+3 4.9E+6 5.7E+3
1980 9.4E+6 9.4E+3 5.8E+6 8.7E+3
1981 7.7E+6 6.4E+3 4.7E+6 7.8E+3
1982 5.0E+6 3.5E+3 2.5E+6 5.6E+3
1983 7.4E+6 e 4.3E+6 e
1984 1.8E+6 1.3E+3 9.3E+5 2.2E+3
1985 8.5E+5 9.1E+2 5.2E+5 2.0E+3
1986 1.3E+5 9.1E+1 6.0E+5 2.9E+3
1987 9.3E+5 e 6.8E+5 e
1988 6.4E+5 e 6.0E+5 e
a Data extracted from Uranium Industry Annual - 1988 (EIASSa).
b Quantities are expressed in metric tons (MT), e.g., 1.1E+6 MT means 1,100,000 metric tons.
c Value is less than 900 MT.
d Value is less than 91 MT.
e For 1983,1987, and 1988, data for surface and underground mine production totals were not
reported separately. Ore quantities are estimated using the average of 3 previous years.
B-l-5
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the rock is easily crumbled, it is removed by tractor-mounted ripper bars, bulldozers, shovels,
or pushload scrapers. If it is not, drilling and blasting are required. The overburden is then
trucked to a nearby waste dump. Occasionally, dikes and ditches are constructed around
these waste piles to collect runoff and divert it to sedimentation ponds. Overall, an area of
tens of hectares may be covered by stored overburden (EPA83). For example, an area! survey
of 10 surface mining sites located in New Mexico (8) and Wyoming (2) indicated that the
disturbed areas varied from 1.1 to 154 hectares, with an average of 44 hectares per site (1
hectare is equivalent to 2.5 acres).
At some sites, as mining progresses, the overburden is used to backfill mined-out areas
of the open pit. In these cases, when an area is completely backfilled, it is graded to conform
to the surrounding topography and to restore the natural drainage patterns. The area is then
covered with top soil and seeded to blend with the natural terrain. Most of the older surface
mines were not backfilled, nor are many of the currently active surface mines.
Underground Mining
Underground mining is much less disruptive to the surface terrain than open pit
mining. In underground mining, access to the ore body is gained through one or more
vertical shafts, generally sunk to a slightly greater depth than the ore body, or through
inclines, declines, or adits, all cut through waste rock. Ore deposits are closely followed
during mining to minimize the amount of waste material which must be brought to the
surface. When mining in large deposits, other mining methods are used, for example, the
room and pillar technique. This technique involves caving-in a large section of ore deposits.
The ore is broken by drilling and blasting and then brought to the surface. The ore and
waste is moved out of the mine through tunnels and shafts leading to the surface. The waste
rock is removed to a spoils area that may be surrounded by a ditch to contain water runoff.
The surface area affected by underground mining activities generally involves less than about
20 hectares, but the underground mine-works may extend laterally for more than a mile in
several directions and at several depths. For example, an area! survey of 10 underground
mining sites located in New Mexico (9) and Wyoming (1) indicated that the disturbed surface
areas varied from 0.9 to 17 hectares, with an average of 12 hectares per site (EPA83).
B-l-6
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1.2.3 Other Mining Methods
Other uranium mining methods include heap leaching, in situ min ag, and mine water
redrculation. These methods have become more common in recent year ; (EPA83, EIA88a).
However, they are not anticipated to create a significant amount of overbi rden in comparison
to the inventory of surface and underground mine waste. Both heap 1 aching and in-situ
mining are performed by adding chemicals to leach the Cranium from ire materials. The
leachate is subsequently processed to recover the uranium. In 1978, ne: rly 7 percent of the
total U3O8 production was associated with such mining methods (EPA8I >. The contribution
from *hia sector has continually increased since 1978 and, on the averaj 2, about 20 percent
of uranium ore production is currently due to these mining methods (E A88a).
1.3 ORE AND WASTE PRODUCTION
At the onset of the uranium mining industry, most of the ore /as recovered from
deposits located at or near the surface. As easily accessible ore deposi * became depleted,
mining had to be performed at increasing depths. In addition, lower grac ; ore deposits, once
ignored, were later mined by using improved mining methods and more efficient ore
extraction techniques.
In the early mining years, an ore grade of 0.15 percent was typi ally ignored, while
more recent mining practices target ore grades as low as 0.03 percent (E' A83). Accordingly,
the mining industry has, over the years, been required to move larger uantities of topsoil
and overburden in order to reach less accessible or lower grade ore depo its. The amount of
overburden which must be removed to expose the uranium ore is also known to be
significantly different for surface and underground mines.
Characteristics of uranium mine wastes vary with the geologic fo mation from which
they are extracted. Only about 5 percent of domestic production is fron vein-type deposits
(generally in metamorphic or igneous rocks). The majority of the ure .iium ore has been
mined in geologic formations which include sandstone, claystone, si tstone, shale, and
limestone deposits. Other materials routinely or occasionally contained vith ores or mining
B-l-7
-------
wastes may include silt, gravel, sand, volcanic ash, and lignite. Mine wastes derived from
sandstone deposits typically consist of various proportions of sand, silt, soil, and sandstone
as rocks, cobbles, and boulders. Rock and waste materials vary in size from small particles
to large boulder size rocks. Typically, such wastes are stored in areas which are
unconsolidated and not reclaimed. The overburden or spoil areas have poor textural
properties, do not support vegetative growth, and have very poor water-holding capacities.
Since most of these sites are located in arid regions of the United States, spoil areas are
usually barren.
1.3.1 Waste Vol""te Projections
Table B.l-3 presents yearly uranium ore production and estimated overburden
generation rates for both surface mines and underground mines. The rationale for the bases
used to estimate overburden generation rates is explained in the following paragraphs.
The ratio of overburden to ore produced in an open pit mine can vary from 10:1 to as
high as 80:1 (EPA83). This ratio is thought to have been fairly constant (about 9 to 12) from
1948 to the late 1950s. From about 1960 to the early 1980s, the ratio has progressively
increased from a low of about 15 to an estimated high of 77 for large surface mines. For
example, over a three decade period, the ratio was about 20 during the 1960s, about 30 by
1970, and between 40 to 50 by the mid 1970s. The EPA, in its Report to Congress, assumes
an average ratio of 50:1 since most of the sites are comprised of smaller mining facilities
(EPA83). For this report, four waste to ore ratios are applied to the yearly ore production
rates to estimate the generation of overburden wastes from surface mines. A ratio of 10:1
is assumed to characterize practices from 1948 to 1960, 25:1 from 1961 to 1970, 40:1 from
1971 to 1980, and 60:1 from 1981 to 1988. This approach is used to more correctly reflect
practices over the past 40 years since applying a single ratio of 50:1 for all years would
overestimate the amount of waste generated during the first three decades.
Underground mines are exploited in a way that minimizes the removal of waste rock,
resulting in much smaller spoil storage piles than those at surface mines. As opposed to
surface mines, the waste to ore ratio is often less than one for underground mines. It is
estimated that the waste to ore ratio generally ranges from 1:20 to 1:1, with an average ratio
B-l-8
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Table B.l-3. Estimated uranium mining overburden production.8
Year
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
Surface
Ore
(MT)
<9.0E+2
9.1E+2
2.1E+4
2.5E+4
5.9E+4
1.6E+5
2.4E+5
3.4E+5
1.1E+6
1.5E+6
2.1E+6
2.0E+6
2.2E+6
2.3E+6
1.6E+6
1.7E+6
1.4E+6
1.1E+6
1.2E+6
1.4E+6
2.1E+6
2.0E+6
2.5E+6
3.0E+6
3.5E+6
4.1E+6
Mines*
Overburden
(MT)C
9.0E+3
9.1E+3
2.1E+5
2.5E+5
5.9E+5
1.6E+6
2.4E+6
3.4E+6
1.1E+7
1.5E+7
2.1E+7
2.0E+7
2.2E+7
5.8E+7
4.0E+7
4.3E+7
3.5E+7
2.8E+7
3.0E+7
3.5E+7
5.3E+7
5.0E+7
6.3E+7
1.2E+8
1.4E+8
1.6E+8
Underground Minesb
Ore
(MT)
3.4E+4
1.6E+5
2.1E+5
2.9E+5
3.4E+5
5.0E+5
7.6E+5
l.OE+6
1.6E+6
1.9E+6
2.6E+6
4.3E+6
5.1E+6
5.0E+6
4.8E+6
3.7E+6
3.4E+6
2.8E+6
2.7E+6
3.4E+6
3.7E+6
3.4E+6
3.2E+6
2.7E+6
2.3E+6
1.8E+6
Overburden
(MT)d
1.1E+4
5.3E+4
7.0E+4
9.7E+4
1.1E+5
1.7E+5
2.5E+5
3.3E+5
5.3E+5
6.3E+5
8.7E+5
1.4E+6
1.7E+6
1.7E+6
1.6E+6
1.2E+6
1.1E+6
9.3E+5
9.0E+5
1.1E+6
1.2E+6
1.1E+6
1.1E+6
2.7E+6
2.3E+6
1.8E+6
B-l-9
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Table B.l-3. Continued.
Year
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
40-yr period
20-yr period
10-yr period
Surface
Ore
(MT)
3.8E+6
3.9E+6
4.2E+6
5.1E+6
7.5E+6
8.8E+6
9.4E+6
7.7E+6
5.0E+6
3.4E+6
1.8E+6
8.5E+5
1.3E+5
7.4E+5
6.3E+5
1949-1988:
1969-1988:
1979-1988:
Mines*
Overburden
(MT)C
1.5E+8
1.6E+8
1.7E+8
2.0E+8
3.0E+8
3.5E+8
3.8E+8
4.6E+8
3.0E+8
2.0E+8
1.1E+8
5.1E+7
7.8E+6
4.4E+7
3.8E+7
3.9E+9
3.5E+9
2.0E+9
Underground Minesb
Ore
(MT)
2.6E+6
2.5E+6
3.6E+6
4.3E+6
5.5E+6
4.9E+6
5.8E+6
4.7E+6
2.5E+6
4.3E+6
9.3E+5
5.2E+5
6.0E+5
5.6E+5
4.7E+5
Overburden
(MT)d
2.6E+6
2.5E+6
3.6E+6
4.3E+6
5.5E+6
4.9E+6
5.8E+6
4.7E+6
2.5E+6
4.3E+6
9.3E+5
5.2E+5
6.0E+5
5.6E+5
4.7E+5
6.9E+7
5.3E+7
2.5E+7
a Data extracted from Uranium Industry Annual - 1988 (EIA88a).
b Quantities are expressed in metric tons (MT), e.g., 1.1E+6 means 1,000,000 metric
tons.
c Amount of overburden materials from surface mines is calculated by applying a waste
to ore ratio of 10:1 from 1948 to 1960,25:1 from 1961 to 1970,40:1 from 1971 to 1980,
and 60:1 from 1981 to 1988.
d Amount of overburden materials from underground mines is calculated by applying
a waste to ore ratio of 1:3 from 1948 to 1970, and 1:1 from 1971 to 1988.
B-l-10
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of about :9 (EPA83). As with surface mining, this ratio has also increased over the years
from wit} m a range 1:5 to 1:2.5 until the early 1970s to about 1:1 by the late 1970s. For the
purpose < f this report, the ratio of overburden to ore for underground mines is assumed to
be 1:3 fro a 1948 to 1970 and 1:1 from 1971 to 1988. This approach is used to more correctly
reflect pr ctices over the past 40 years since applying a single ratio of 1:9 for all years would
significar iy underestimate the amount of waste generated during the last two decades.
Ti ile B.l-3 shows that the total volume of uranium mine waste produced since the
inception of the industry is about 4 billion metric tons. Most of this waste (almost 90
percent) as been produced by surface mining during the past 20 years. Wastes produced
from sur ice uranium mines are substantially greater (by a factor of about 50) than the
volume p oduced from underground mines; and, therefore, the production from surface mines
is the det .-rmining factor in estimating the total NORM inventory. Of the more than 1,300
surface u aninm mines identified in Table B.l-2, over 1,000 have had ore production of less
than 900 VTT. Mines of this size typically have few or no waste piles associated with past
waste pn luction. As a result, the NORM inventory is most predicated by the remaining 257
surface n mes producing more than 900 MT (SCA89). Since the last 20 years includes the
period of leaviest surface mining, future projections based on this time period would yield
highly co servative estimates, unless there is a major upturn in the demand for uranium.
Fc example, assuming that the generation of overburden remains the same as that
observed rom 1985 to 1988, since ore production has reached a new plateau, the 20-year
waste prc action is 700 million MT versus 3.5 billion MT, which is the total 20-year inventory
from 196. to 1988. Since most of the demand for uranium originates from the commercial
sector (m dear power plants), it is anticipated that, in view of the downturn in new plant
construct on, the future production rate of uranium will be one which matches existing needs
for refuel ig rather than supporting the demand of new power plants (EIA88b, EIA88c). The
domestic '.emand for uranium is also partially met by importing UgOg from abroad (EIA88a).
Since 19? *>, imports of uranium have continually increased from about 640 MT to 7,200 MT
in 1988 (1 IA88a). An increase in uranium imports would further reduce mining activity in
the Unite 1 States and consequently reduce the generation of overburden waste.
B-l-11
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Reclaimed Versus Unreclaimed Material
The projected waste inventory and its potential to cause elevated exposures to the
public must also take into consideration the fact that certain states have implemented
regulatory controls requiring the submittal of a reclamation plan and bond prior to the
issuance of a mining permit. The purpose of reclamation is to return the excavated areas to
more aesthetic conditions and reduce the potential for surface water runoff and erosion. This
generally consists of backfilling, regrading, and seeding the excavated areas. Though these
programs are not explicitly designed to mitigate potential radiological risks, such measures
do reduce potential exposures to direct radiation, radon, fugitive dust emissions, and the
possibility that materials will be removed and used in construction applications.
Some mines which were subject to State regulations have been reclaimed, but the
number of such mines still makes up a small fraction of the total. For example, the EPA
estimated that by 1971 approximately 6 percent of the land used for uranium mining had
been reclaimed. Mines operating prior to the implementation of regulations requiring
reclamation (such as the Wyoming Environmental Quality Act of 1973 and the Texas Surface
Mining Act of 1975) and mines located in states not implementing such controls are generally
still unreclaimed today. The exceptions are Texas and Wyoming where alternative funds
have been allocated for reclamation. Any future reclamation activities will most likely alter
the existing and projected volumes of unreclaimed waste.
The reclamation status of mines within various mining districts differs greatly
depending upon state regulations. Two primary reclamation techniques are used, Class I and
Class II. Class I reclamation is defined as complete backfilling followed by the application
of topsoil, contouring, and re-vegetation. It is assumed that following Class I reclamation,
the potential for exposure of the public has virtually been eliminated and the site returned
to its original or near original condition. Therefore, the post-reclamation impact from Class I
reclamation is about the same as the impact before any mining took place. Class II
reclamation may consist of regrading, contouring, sloping, application of topsoil and
re-vegetation of waste piles and pit surfaces. Waste materials are not usually totally
returned to mined-out areas.
B-l-12
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Table B.l-4 presents estimates of the number of sites and mining regions which have
been subjected to some form of reclamation based on a study conducted in support of the 1989
NESHAPS (SCA89, EPA89). Table B.l-4 takes into account the number of mines in each
reclamation classification for three ore production ranges:.less than 900 MT, from 900 to
90,000 MT, and greater than 90,000 MT. These uranium ore production ranges reflect a
Department of Energy survey scheme to classify various mining facilities (EPA83). As can
be noted from Table B.l-4, only a small fraction of mining facilities have been subjected to
Class I reclamation.
1.3.3 Uranium Overburden Utilization
Most uranium mining has taken place in rural or desolate areas of the southwest and
western regions of the United States. Most mines are located on private property or on
government owned land. Overburden materials are typically stored on-site. Because of the
large volumes involved, the materials are moved, if at all, only to short distances from the
mining areas. Overburden wastes have been used on-site to construct roads and as road
ballast. Because of the coarse and rough form of such materials, there is no known direct use
of overburden wastes which involve large volumes (EPA83). It should be noted that there
is a paucity of information and data characterizing past uses and applications of such waste.
Field investigations have identified locations of higher than normal radiation exposure
rates in local and nearby mining communities (EPA83, CRC81, NCR87, DOE88). Typically,
most of the materials observed or used in nearby communities are characterized as tailings,
ore spillage, ore specimens, low-grade crushed ore, and mine wastes. Past experience has
shown that by far the most prevalent misuse of any uranium wastes (in large quantities) has
involved mill tailings (DOE88). It is unlikely that valuable ores would be used at off site
locations; rather the use of mining materials would typically involve mining wastes
or processed materials which have little value for ore production and which have desirable
characteristics for construction applications.
Given the physical characteristics of uranium overburden wastes, it is unlikely that
this material would be used in construction of residential or commercial structures. For
B-l-13
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Table B.l-4. Surface uranium mining industry based on regional reclamation.8
I. For production ranges of 900 to 90.000 metric tons.
State
Arizona
California6
Colorado
Idaho6
Montana6
Nevada6
New Mexico
North Dakota
Oregon
South Dakota
Texas
Utah
Washington
Wyoming
Number of
Production
37
1
12
1
1
1
3
10
1
33
19
6
3
66
$ni*fnoA ITrnnii
Mln b
t
Reclamation Distribution
Class I
0
0
0
0
0
0
0
0
0
0
1.9
0
0
M
Class II
2
0
2.4
0
0
0
0.5
0.5
0
1.7
8.6
0
1.5
26.4
Unreclaimed
35
1
9.6
1
1
1
2.5
9.5
1
31.3
8.5
6
1.5
36.3
Total
194
5.2
43.6
145.2
Data derived from two reports characterizing radiological conditions at surface
uranium mines (SCA89, EPA89).
Many mines have been partially reclaimed, hence the data are presented in
fractional form in some instances.
Sites are assumed to be unreclaimed for the lack of better information.
B-l-14
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Table B.l-4. Continued.
IL For production greater than 90.000 metric tons.
Number of Surface Uranium Minesb
Reclamation Distribution
State
Arizona
California0
Colorado
Idaho0
Montana0
Nevada0
New Mexico
North Dakota
Oregon
South Dakota
Texas
Utah
Washington
Wyoming
Production
1
0
4
0
0
0
5
0
1
2
25
0
2
31
Class I
0
0
0.2
0
0
0
0
0
0
0
2.5
0
0
L6
Class n
0
0
0.8
0
0
0
0.8
0
0
0.1
11.3
0
1
12.4
Unreclaimed
1
0
3
0
0
0
4.2
0
1
1.9
11.2
0
1
17.0
Total
71
4.3
26.4
40.3
a Data derived from two reports characterizing radiological conditions at surface
uranium mines (SCA89, EPA89).
b Many mines have been partially reclaimed, hence the data are presented in fractional
form in some instances.
c Sites are assumed to be unreclaimed for the lack of better information.
B-l-15
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example, overburden materials would need to first be sorted to remove large boulders and
rocks and then crushed or pulverized to form a material which would be in a suitable form
for construction applications, e.g., as an additive to concrete, bricks, concrete blocks, grouts,
etc. Since other types of construction materials are readily available, typically at much lower
costs, it is not likely that uranium overburden materials will displace other competing
products. Given that it is unlikely that overburden wastes may be misused in the
construction of residential or commercial structures, the other more likely type of exposure
which may present some radiological risks involves land use, such as use of the land for
grazing, agricultural croplands, and residential or commercial developments.
The use of former mining sites for grazing beef cattle or for agricultural croplands
would necessitate that former sites first be reclaimed in order to support vegetative growth.
As was noted earlier, overburden or spoil areas have poor textural properties, do not support
vegetation, and have very poor water-holding capacities. For this type of land to become
productive, even typical reclamation measures may not be adequate. Since most uranium
mine sites are located in arid and barren regions of the United States, waste dump areas are
devoid of a top soil layer with the necessary plant nutrients and sufficient water to support
most forms of agricultural production. If typical reclamation measures were implemented,
such sites might possibly become suitable as grazing ranges for beef cattle.
It is difficult to determine if former mining sites could be developed into residential
or commercial property. Given that such sites are generally located in remote areas, it is
unlikely that abandoned or reclaimed sites would become busy urban developments. Since
some older mines are now being exploited, a more likely scenario is one in which temporary
housing is built at the site to support the work force engaged in the mining effort. As was
noted earlier, the productive life of these mines is relatively short, typically 3 to 6 years. In
this scenario, only a small transient work force would remain at the mining site.
Twenty-Year Projection of Unreclaimed Waste
As was discussed above, the reclamation status of mines within various mining
districts differs greatly depending upon state regulations. Two primary reclamation
techniques are used, Class I and Class n. It is assumed that following Class I reclamation,
B-l-16
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the potential for exposure of the public has been virtually eliminated and the site has been
returned to its original or near original condition. Therefore, all sites which have been
subjected to Class I reclamation are assumed to present no additional risks above the natural
background environment. For Class II reclamation, the mine waste inventories are assumed
to be 50 percent of completely reclaimed mines. Mines classified as totally unreclaimed are
assumed to have all of the estimated waste inventory (100 percent) remaining at the site in
an unstabilized form.
Based on Table B.l-4 estimates, the number of surface mines in each ore production
range are used to calculate the quantities of remaining overburden wastes for each
reclamation classification. The amount of ore generated is estimated on the basis of the
number of sites which have been subjected to reclamation, the total ore production for each
of the three categories of mines, and total ore production from 1948 to 1988. In addition, it
is assumed that the waste to ore ratio varies as a function of the size of the mine. Based on
the EPA Report to Congress, the following waste to ore ratios are applied: 10:1 for small
mines which produce less than 900 MT, 30:1 for mid-size mines which produce between 900
to 90,000 MT, and 50:1 for large mines which produce more than 90,000 MT of ore (EPA83).
From a total of 1,305 mines, it is assumed that 1,040 mines have an average production of
300 MT each, or 1/3 of the range assuming a rough geometric distribution. For 194 mines
which produce between 900 and 90,000 MT, the ore production is assumed to be 30,000 MT,
also based on 1/3 of the range. For the remaining 71 larger mines, the ore production is
assumed to be 1.1 million MT based on an EPA characterization of larger facilities (EPA83).
The largest mines are assumed to have a yearly ore production rate ranging from
about 70,000 to 140,000 MT given that the productive life of a mine typically varies from 8
to 15 years (EPA83). For the sake of comparison, the EPA in its Report to Congress assumes
that the average mine generates 120,000 MT of ore per year. The estimated total
unreclaimed overburden, generated over the period of 1948 to 1988 is 3.1 billion MT. It
should be noted that this amount represents nearly 80 percent of the total overburden waste
generated since 1948 and about 89 percent of the amount produced from 1968 to 1988. The
breakdown by reclamation Class is as follows:
B-l-17
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Total
Unreclaimed Overburden (MT)(a)
Mine Category
Less than
900 MT
From 900 to
90,000 MT
Greater than
90,000 MT
Class 1
0
0
0
Class II
"o
2.0E+7
7.3E+8
Unreclaimed
3.1E+6
1.3E+8
2.2E+9
Total
3.1E+6
1.5E+8
2.9E+9
7.5E+8
2.3E+9
3.1E+9
(a) 3.1E+6 means 3,100,000 MT.
Given the uncertain status of the uranium mining industry, it is difficult to predict
future generation rates. As can be seen from Table B.l-2, the uranium mining industry has
taken a downturn since the early 1980s. The current ore production rate (for 1988) is
typically less than 10 percent of the productive capacity experienced during the mid-1970s.
Production is also shifting away from surface mines to underground mines, since the gradual
depletion of surface mines requires that uranium be mined at increasing depths.
Underground mining is also taking place at older or abandoned mines since it is too costly
to develop new mines. Mining methods are also being more selective by targeting smaller
but richer ore deposits or veins (PIE89). By today's standards, significant amounts of
uranium still remain in these older mines. In the early mining years, an ore grade of 0.15
percent was typically ignored, while current mining practices target ore grades as low as 0.03
percent (EPA83).
Uranium can also be supplied from other sources since U3O8 may be extracted, as a
by-product material, from other mineral mining activities, e.g., from phosphoric acid
r
production, and extraction from copper mine wastes. Such alternate sources have supplied
relatively small quantities, e.g., less than 1,000 MT in 1978 and current trends indicate that
the number of such sources has continually decreased every year since 1981 (DOE88).
The productive life span of a uranium mine is also becoming much shorter. The EPA,
in its 1983 Report to Congress, assumed that the typical life of a mine was about 8 to 15
years (EPA83). A review of current mining practices, however, reveals that the typical mine
B-l-18
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is operational for only 3 to 6 years (PIE89, EPA89). Furthermore, it is anticipated that, at
least in the foreseeable future, there will not be a growth in the nuclear power industry
which would parallel the demand for uranium noted during the 1970s. Finally, there is the
possibility that uranium imports may increase to still higher levels (EIA88a).
It is also safe to assume, given the more restrictive regulatory climate of the 1980s
compared to the 1960s and 1970s, that even if the nuclear industry were to rebound, mining
practices and reclamation activities will be conducted under more stringent regulations. New
regulations would likely result in the generation of smaller quantities of overburden and
institute some mandatory levels of reclamation on all new mining sites.
Accordingly, for this NORM sector the potential problem associated with the storage
or use of overburden materials at uranium mine sites does not necessarily depend upon
future activities, but rather on activities at existing sites. These sites include those that are
still active and those that have yet to be reclaimed.
1.4 RADIOLOGICAL PROPERTIES OF URANIUM MINE WASTE
1.4.1 Radionuclide Concentrations
The concentration of naturally-occurring radioactivity in mining wastes is known to
vary significantly (EPA85, NRC80, UNS82). In an EPA study of 58 samples taken from
uranium mines it was noted that 69 percent had radium concentrations greater than or equal
to 5.0 pCi/g, and 50 percent had concentrations greater or equal to 20 pCi/g. In a separate
study, the EPA estimated that waste rock from uranium mining has average U-238 and
Th-232 concentrations of 6.0 and 1.0 pCi/g, respectively (EPA83).
The results of recent field studies indicate that the average Ra-226 concentration in
mine overburden is about 23.7 pCi/g, based on area weighted sample results in five states
(SCA89). The range of Ra-226 concentration was noted to vary from about 3 pCi/g to several
hundred pCi/g at the interface of overburden and low* grade ore boundaries. Background
B-l-19
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Ra-226 concentrations are usually lower, typically ranging from about 1 to 7 pCi/g. The
radium concentrations are estimated to be in equilibrium with parent members of the U-238
decay series, including U-238, U-234, and Th-230. For this report, it is assumed that the
Ra-226 concentration in mining overburden is 23.7 pCi/g based on the above discussion and
field data. The estimated radionuclide concentrations are as follows:
Radionuclide Concentration (oCi/g)
Po-210 16.6
Pb-210 16.6
Ra-226 23.7
Th-228 1.0
Ra-228 1.0
Th-230 23.7
Th-232 1.0
U-234 23.7
U-235 1.2
U-238 23.7
Po-210 and Pb-210 concentrations are derived by applying a radon emanation
coefficient of 0.3, assuming that the radionuclides are contained in a sandstone matrix
(NRC84). The U-235 concentration is assumed to be 5 percent that of the U-238. Thorium
and its decay chain members, Th-232, Ra-228, and Th-228, are assumed to be in secular
equilibrium at a background concentration of about 1.0 pCi/g.
1.4.2 Radon Flux Rates
The concentration of long-lived radon daughters in the waste is based on the Ra-226
concentration and consideration of losses due to radon emanation and diffusion from the pile
(NRC82). Field data (SCA89) indicate a large variation in radon emanation coefficients,
ranging from approximately 0.1 to 0.5. Field measurements also indicate that average radon
flux rates vary from about 2 to 60 pCi/m2-s for overburden materials and as high as few
hundred pCi/m2-s for low grade ore materials (SCA89, EPA89). The flux rate averaged over
25 mines was estimated to be 11.1 pCi/m2-s for overburden materials. The large range of
radon flux values is due to the wide range of radium concentrations found in overburden and
B-l-20
-------
low grade ore materials. For comparison, background radon flux rates are known to vary
from about 0.6 to 5.0 pCi/m2-s (SCA89, NRC80).
As was discussed earlier, it is difficult to characterize radon emanation or flux rates
from such materials because of their diverse physical form and emplacement disposal or
storage methods. For example, particle grain size and the presence and thickness of a cover
will govern the radon emanation rates.
For thig report, a simple approach is used to estimate the radon release rates from
overburden piles. A radon emanation coefficient of 0.3 is used, based on the assumption that
mining is occurring in sandstone formations (NRC84). Since the amount of overburden far
exceeds the volume of low grade ore materials, it is assumed that any radon emanation from
low-grade ore materials will most likely have little additional impact on the average
emanation rate associated with the overburden waste alone.
1.4.3 Extern** 1 Radiation Exposure Rates
In support of the characterization of 25 uranium mine sites located in five states,
external radiation measurements were taken on overburden piles (SCA89, EPA89). The field
measurements revealed that exposure rates from overburden materials, on the average,
varied from 20 to 110 uR/hr, with a mean of about 40 uR/hr. Exposure rates from low-grade
ore materials were usually higher, ranging from 80 to nearly 1,000 uR/hr, with an average
of 200 uR/hr. Exposure rates associated with ambient background levels were noted to range
from 10 to 85 uR/hr, averaging about 20 uR/hr.
B-l-21
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1.5 GENERIC SITE PARAMETERS AND SECTOR SUMMARY
1.5.1 Generic Overburden Site
The reference location for a surface uranium mine is south central Texas. This area
was chosen due to a localized concentration of larger surface mines, more extensive land use,
and relatively higher population density compared to sites in Colorado, South Dakota, New
Mexico, and Wyoming. The reference site is assumed to be an unreclaimed and abandoned
surface mine. Total ore production from the mine is estimated to be 1,100,000 MT, which is
similar to large mine production in Wyoming, Colorado, and Texas (SCA89). The waste
inventory is calculated using the 50:1 waste to ore ratio applied to large surface uranium
mines, yielding a total waste volume of 55 million metric tons.
As previously mentioned, the generic site contains an uncovered and unreclaimed
overburden pile with an associated mine pit. The effective volume of the waste pile is 28
million m3, assuming a density of 2.0 g/cm3. The pile is assumed to be approximately square,
each side having a length of 1,200 m, and to have a height of 20 m.
1.5.2 Population Exposure
Population distributions around former mining sites are believed to have either
remained constant or possibly decreased because of the downturn of the uranium industry
since the beginning of this decade. The EPA, in its 1983 Report to Congress, characterized
the population density around mining sites in 121 counties located in 17 states based on 1975
population estimates (EPA83). Based on the results of the 1980 census and 1986 update, the
population in these states has increased, on the average, by about 45 percent since 1975
(BOC87). Population densities, adjusted for the 1986 population estimates, are reported to
average 6.4 persons per km2 (1 square mile is equal to 2.6 square kilometer) based on a total
population of 9.6 million and a land area of 1.5 million square kilometers. With the exception
of 22 counties, all remaining 99 counties were characterized by population densities of less
than 10 persons per km2. In the 22 most populous counties, population densities varied from
10 to 174 persons per km2, with an average of 41 persons per km2.
B-l-22
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For the purpose of this assessment, a population density of 64 persons per square mile
is assumed, based on Texas population data (BOC87).
1.5.3 Radionuclide Concentrations
As noted previously, the concentration of naturally-occurring radioactivity in mining
wastes is known to vary significantly. For this risk assessment, radionuclide concentrations
are based on the results of field studies and published data in the open literature. Radium
concentrations are estimated to be in equilibrium with parent members of the U-238 decay
series, including U-238, U-234, and Th-230. Po-210 and Pb-210 concentrations are derived
by applying a radon emanation coefficient of 0.3. The U-235 concentration is assumed to be
5 percent that of U-238. Thorium (Th-232) decay chain members, Ra-228, and Th-228, are
assumed to be in secular equilibrium at a background concentration of about 1.0 pCi/g. The
reference radionuclide concentrations used in the uranium overburden risk assessment of
Chapter D are given in Section 1.4.1.
B-l-23
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B.1 REFERENCES
BOC87 Department of Commerce, Statistical Abstract of the United States - 1988,
Bureau of Census, 108th Edition, December 1987.
CRC81 Conference of Radiation Control Program Directors, Natural Radioactivity
Contamination Problems, Report No. 2, August 1981.
DOE88 Department of Energy, Integrated Data Base for 1988: Spent Fuel and
Radioactive Waste Inventories, Projections, and Characteristics,
DOE/RW-0006, Rev.4, September 1988.
EIA88a Energy Information Agency, Uranium Industry Annual-1988, Department of
Energy, DOE/EIA-0478(88), August 1989.
EIA88b Energy Information Agency, Annual Outlook for U.S. Electric Power - 1988,
Department of Energy, DOE/EIA-0474(88), August 1988.
EIA88c Energy Information Agency, Commercial Nuclear Power - 1988, Department
of Energy, DOE/EIA-0438(88), September 1988.
EPA83 Environmental Protection Agency, Potential Health and Environmental
Concerns of Uranium Mines Wastes, Report to the Congress, EPA
520/1-83-007, June 1983.
EPA85 Environmental Protection Agency, Wastes form the Extraction and
Benefication of Metallic Ores, Phosphate Rock, Asbestos, Overburden from
Uranium Mining, Report to Congress, EPA 530/SW-85-033, December 1985.
EPA89 Environmental Protection Agency, Background Information Document
Proposed NESHAPS for Radionuclides, Draft, SC&A, Inc. report prepared for
the U.S. EPA 520/1-89-006, February 1989.
NCR87 National Council on Radiation Protection and Measurements, Exposure of the
Population in the United States and Canada from Natural Background
Radiation, NCRP Report No. 94, December 1987.
NRC80 Nuclear Regulatory Commission, Final Generic Environmental Impact
Statement on Uranium Milling, NUREG-0706, Vol. Ill, September 1980.
NRC82 Nuclear Regulatory Commission, Radon and Aerosol Release from Open Pit
Uranium Mining, Pacific Northwest Laboratory Report PNL-4071, prepared for
the U.S NRG, NUREG/CR-2407, August 1982.
NRC84 Nuclear Regulatory Commission, Radon Attenuation Handbook for Uranium
Mill Tailings Cover Design, NUREG/CR-3533, April 1984.
B-l-R-1
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PIE89 Pierce, P.E., Senior Mining Engineer, telephone communication, September 18,
1989.
SCA89 Radiological Monitoring at Inactive Surface Uranium Mines, Roy F. Weston,
Inc., report prepared for SC&A, Inc. under EPA contract, February 1989.
UNS82 United Nations Scientific Committee on the. Effects of Atomic Radiation,
Ionizing Radiation: Sources and Biological Effects, No. E.82.EX.8, United
Nations, 1982.
B-l-R-2
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B.2 PHOSPHATE AND ELEMENTAL PHOSPHOROUS WASTES
2.1 INTRODUCTION
Mining of phosphate rock (phosphorite) is the fifth largest mining industry in the
United States in terms of quantity of material mined (EPA84). The southeastern U.S. is the
center of the domestic phosphate rock industry, with Florida, North Carolina, and Tennessee
having over 90 percent of the domestic rock production capacity. Florida, with approximately
80 percent of the current domestic capacity, dominates the U.S. industry and is the world's
largest phosphate rock producing area. The western U.S. phosphate rock industry is located
in eastern Idaho, northern Utah, western Wyoming, and southern Montana.
The principal ingredient of phosphate rock (or phosphorite) that is of economic interest
is an amorphous form of the mineral apatite (franoolite or carbonate-fluorapatite). Phosphate
rock is processed to produce phosphoric acid and elemental phosphorous. These two products
are then combined with other chemicals to produce phosphate fertilizers, detergents, animal
feeds, other food products, and phosphorous-containing chemicals. The most important use
of phosphate rock is the production of fertilizers, which accounts for about 80 percent of the
mining of phosphorite in the United States.
Uranium in phosphate ores found in the U.S. ranges in concentration from 20 to
300 ppm (or about 7 to 100 pCi/g) (DEV79), while thorium occurs at lower concentrations,
between 1 to 5 ppm (or about 0.1 to 0.6 pCi/g) (BLI88). Phosphogypsum is the principal
waste byproduct generated during the phosphoric acid production process. Phosphate slag
is the principal waste byproduct generated from the production of elemental phosphorous.
Some of the impurities contained in the phosphogypsum and phosphate slag include uranium
and thorium and their radioactive decay products, which are known to exist at elevated
concentrations. Since large quantities of phosphate industry wastes are produced, there is
a concern that these waste materials may present a potential radiological risk to exposed
individuals if the wastes become distributed in the environment.
B-2-1
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In the sections which follow, a description of the phosphate industry is provided along
with a characterization of the properties of phosphate products and wastes. Actual and
projected amounts of waste materials produced by this NORM sector are also given based on
past and current industry practices.
This information is used to assess potential exposures to members of the general
public and critical population group. A radiological risk assessment is performed (see
Chapter D) assuming that the exposed population is residing near a generic facility.
2.2 OVERVIEW OF PHOSPHATE INDUSTRY
The 1988 U.S. production of phosphate rock has been estimated to be 38 million metric
tons (MT), while the industry has a productive capacity of 50 million MT (TFI89). U.S
production peaked in 1980 when it produced 54 million MT (TVA86). Production has since
been decreasing at about 2 percent per year (TVA86, BOM88, TFI89). Phosphate rock
inventories have similarly decreased, from 15 to 7.5 million MT in 1985 and 1988,
respectively (TFI89). The industry's total productive capacity is also following a similar
trend. Phosphate rock is mined in open-pit mines, half of which are located in Florida, with
the remaining half scattered in Tennessee, Idaho, Montana, Wyoming, Utah, and North
Carolina, see Figure B.2-1.
Phosphate ore consists of one-third quartz sand, one-third various clay minerals, and
one third phosphate particles. After mining the phosphate rock, the ore is processed by
benefidation (washing and flotation processes), followed by drying of the marketable rock.
A flow chart of various phosphate production operations is shown in Figure B.2-2. After
benefidation, the marketable phosphate rock is transformed into either elemental
phosphorous (thermal process), or phosphoric acid (wet-process) for the production of
fertilizer, detergents, animal feeds, food products, and phosphorous-containing chemicals.
About ten percent of the marketable phosphate rock mined in the United States is used for
the production of elemental phosphorus. Regardless of the processing method, most of the
phosphate rock production goes into the making of fertilizers, which accounts for about 80
percent of the production of phosphorite in the United States.
B-2-2
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Offshore
Calif.
LEGEND
Phosphate deposit
Car mo
S. Carolina
E.Georgia
Central
Florida and
Southern Extension '
Figure B.2-1. Major uraniferous phosphate deposits in the U.S.
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Phosphate
Mine
1 Ore Matrix + Water
Beneflciatlon:
Washing
Flotation
Grinding
Drying
Marketable Rock
! 1
Thermal Process:
Blending, sizing
Calcining
Electric Furnace Ferrophoaphorus
Phosphorus Condenser and Slag
wet process: Phosphoric Acid
Drying, Grinding ^ scale
React with Sulfurk Acid
Filter I
Acid Evaporator ^ Pliuupltoyypsum
1 Phosphoric
i I
Elemental L Ammonium 1 + Markotable 1
Phosphorus f f Rock f
Ammonium Triple Super Normal Super
Phosphate Phosphate Phosphate
Fertilizer Fertilizer Fertilizer
Figure B.2-2. Flow diagram of phosphate material and waste production.
-------
2.2.1 Phosphoric Acid Wet-Process
The phosphoric acid production industry in the U.S. consists of 21 facilities that were
active and two that were on standby status as of September 1989 (EPA90a). The locations
of these facilities are shown in Table B.2-1. The average wet-process plant produces about
700 metric tons of phosphoric acid per day (EPA88).
Production
The starting material for the production of phosphoric acid by the wet process is
beneficiated phosphate ore. During beneficiation, phosphate particles are separated from the
rest of the ore, and thus, two types of wastes are produced: 1) phosphatic clay tailings (clay
slime from washer stages of beneficiation), and 2) sand tailings from flotation stages of
beneficiation.
Phosphatic clay tailings (slime) are stored in large settling areas behind earthen dams.
Clear water reclaimed from these settling areas is returned to the mine, providing a source
of water for the wet-process or for use as process water in other parts of the plant.
Sand tailings are either returned to the mine and used as a backfill in mined-out
areas (as is the practice in Florida and North Carolina), used for construction of clay-tailings
retention dams (as is also the practice in Florida), or mixed with clay tailings to increase clay
tailings solids content.
For each 13.3 million MT of phosphorite beneficiated in a typical central Florida
mining operation, 3.3 million MT of phosphatic clay tailings, 7.3 million MT of sand tailings,
and 2.7 million MT of marketable ore are produced annually. About one-half of the
mined-out area is used to store phosphatic clay tailings in retention areas. When introduced
into retention areas, the waste and clay slurry has a solid content of only three to six percent
by weight. Accordingly, the volume of slurried waste clay far exceeds the volume of sand,
phosphate, and clay originally removed from the mined area.
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Table B.2-1. Wet process phosphoric acid plants (Source: EPASOb).
Operator
Location
Agrico
Agrico
Agrico
Arcadian
Central Phos.
OF Chemicals
Chevron Chemical
Conserv
Farmland Inc.
Fort Mead Chemical
Gardinier
IMC Fertilizer
Mobil Mining
Nu-South Ind.
Nu-West
Occidental Chem.
Royster
Royster
Seminole Pert.
J.R. Simplot
Texasgulf
Agrico(a)
Agrico(a)
Donaldsonville, LA
Mulberry (Pierce), FL
Uncle Sam, LA
Geismar, LA
Plant City, FL
Bartow (Bonnie), FL
Rock Springs, WY
Nichols, FL
Bartow (Pierce), FL
Fort Meade, FL
Riverview (Tampa), FL
New Wales (Mulberry), FL
Pasadena, TX
Pascagoula, MS
Soda Springs, ID
White Springs, FL
Mulberry, FL
Palmetto (Piney Ft), FL
Bartow, FL
Pocatello, ID
Aurora, NC
Ft. Madison, LA
Hahnville, LA
Parent Company
Freeport-McMoRan
Freeport-McMoRan
Freeport-McMoRan
Arcadian
CF Industries
CF Industries
Chevron, Corp.
Conserv
Farmland Ind.
US Agric Chem/WR Grace
Gardinier
IMC Fertilizer
Mobil Corp.
Nu-West Industries
Nu-West Industries
Occidental Petroleum
Cedar Holding Co.
Cedar Holding Co.
Seminole Fertilizer
J.R. Simplot
Texasgulf
Freeport - McMoRan
Freeport-McMoRan
(a) On standby in 1989.
B-2-6
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About 36 million MT (dry weight) of waste clay are produced annually in Florida
alone. For each ton of clay solids produced, four to five tons of interstitial water remains
permanently entrapped. More than 20,000 hectares (50,000 acres) of clay tailings settling
areas surrounded by more than 300 miles of earthen dams (up to 12 m high) are now in
existence in Florida (TWN88). The low bearing strengths of reclaimed clay slime retention
areas, even after several decades of settling, limits their use only to agricultural applications.
After benefidation, the marketable phosphate ore is sold to wet-phosphoric acid plants.
Sulfuric acid is used to dissolve the ore; this reaction produces mostly hydrated calcium
sulfate (CaSO^nHgO, i.e., phosphogypsum, which is a waste by-product) and phosphoric acid
(HgPO^, and smaller amounts of hydrofluoric acid (DEV79). The hydrofluoric acid is
eventually turned into fluorosilitic acid, which can become a by-product of fertilizer
production.
Digestion of the phosphate ore by sulfuric acid produces a slurry (phosphogypsum)
which is further processed by filtration. The phosphogypsum is discharged from filter pans,
slurried with water, and pumped to large piles (phosphogypsum stacks). The conditions of
both the phosphate ore and the digester influence the filtration properties of the slurry.
Phosphogypsum typically consists of thick and agglomerated crystals in order to achieve a
good filtration rate and to maximize the production of phosphorus oxide (P2O5). Typical
phosphogypsum particles range in size between 50-100 microns. Most of the sand impurities
fall within this particle size range while the remaining impurities are comprised of particles
which are less than 30 microns in size (CHA87). The final moisture content of
phosphogypsum stacks stabilizes between 20 and 30 percent. Approximately 93 percent of
the waste material is phosphogypsum, with the balance consisting of impurities which
include sand, phosphate, fluorides, radionuclides, and organic constituents. Some of the
radium from the original ore remains and co-precipitates with the calcium sulphate or
phosphogypsum, while the balance, remains with the impurities. As is discussed in Section
2.4, the typical radium-226 concentration in phosphogypsum ranges from 11 to about 33 pCi/g
(EPA75). For each ton of wet-process phosphoric acid, about 4.5 metric tons of
phosphogypsum is produced. As is discussed later in this section, phosphogypsum is
generated in large quantities.
B-2-7
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An additional waste product of radiological concern that is associated with this process
is phosphoric acid scale. In the production of phosphoric acid from the raw ore, the
phosphogypsum must be physically separated from the phosphoric acid by a nitration process.
Large stainless steel filter pans are covered with fiberglass' fabric which serves to filter out
the phosphogypsum while allowing the passage of acid. During this process, small quantities
of scale are deposited on the surface areas of the pan and fiberglass mat. This scale can also
be found deposited in ancillary piping and filtrate receiver tanks that are associated with the
filtration process. Radium-226 concentrations in scales have been found to range from
several hundred to as high as 100,000 pCi/g (KEA88). While the concentrations of
radium-226 are quite high, the volume associated with this scale is relatively low. One
estimate is that a phosphoric acid production plant will generate about 6 m3 of scale per year
(MAR88). Some scale is also deposited within phosphogypsum stacks, either in the
concentrated form, or mixed and diluted with lower concentration phosphogypsum. Because
of the very low volume of this scale compared to the volume of phosphogypsum, phosphoric
acid scale will not be treated further in this report.
2«2«2 EleTnent*»l Phosphorcy? - Therrn**! Process
Elemental phosphorus is used primarily for the production of high grade phosphoric
acid, phosphate-based detergents, and organic chemicals used in cleaners, foods, baking
powder, dentifrices, animal feed, etc. About 70 to 80 percent of the elemental phosphorous
production is used to make phosphoric acid, while the balance is used elsewhere, e.g., for the
making of pesticides and other high grade chemicals (TVA86). There are eight elemental
phosphorus plants in the United States, located in Florida, Idaho, Montana, and Tennessee.
Only five of these plants (in Idaho, Montana, and Tennessee) are presently active. Location,
ownership, estimated capacity, and current status of the plants are shown in Table B.2-2
(EPA84, EPASOa). Production of elemental phosphorus has declined from a peak of 400
thousand MT in 1979 to 310 thousand MT in 1988 (REL89, EPA89a, DOI87, EPA90a).
Between 1978 and 1988, U.S phosphorous production has declined at an effective annual rate
of 2 percent (REL89). In 1986, approximately 20,000 MT of elemental phosphorus were
exported and 4,000 MT were imported. In recent years, most American phosphorous
producers have adjusted to the detergent phosphate bans and rising energy costs. Many
B-2-8
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Table B.2-2. Location and capacity of elemental phosphorus plants.
Location
Company
Florida
Pierce00
Tarpon Springs
North Carolina
Lee Creek(c)
Idaho
Pocatello
Soda Springs
Montana
Silver Bow
Tennessee
Columbia
Columbia00
Mt Pleasant
Mobil Chemical Co.
StaufTer Chemical Co.
Texas Gulf/Olin
FMC Corporation
Monsanto Chemical Co.
StaufTer Chemical Co.
Occidental Chemical Co.
Monsanto Chemical Co.
StaufFer Chemical Co.
Phosphorous
Capacity(a)
(MT/vr)
20,000
23,000
48,000
130,000
90,000
40,000
57,000
75,000
50,000
(a) Estimated capacity in 1984 (EPA84).
(b) These facilities are currently inactive.
(c) Wet-process under construction and scheduled for operation in early 1990 (REL89).
B-2-9
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inefficient plants were shutdown and the productive capacity was concentrated in areas
where energy supplies were the most cost effective.
Phosphorous is produced by the reduction of phosphite rock in large electric furnaces
using carbon and silica as catalysts. The industry favors the use of thermal units rather than
wet-process plants because the former produce phosphorous of a higher grade. Wet-process
plants may require additional processing to produce phosphorous of similar purity. Thermal
units, however, consume large amount of electricity and are preferably located where energy
is the least costly. Crushed and screened phosphate rock is fed into calriners and heated to
the melting point, about 1300°C. After calcining, the hot nodules are passed through coolers
and into storage bins prior to being fed into electric furnaces. The furnace feed consists of
nodules, silica, and coke. A simplified chemical reaction equation for the electric furnace
process is:
2Ca3(PO4)2 + 6SiO2 + IOC = P4 + 10CO + 6CaSiO3
Phosphorus and carbon monoxide, driven off as gases, are vented at the top of the
furnace. Furnace off-gases pass through dust collectors and then through water spray
condensers where the phosphorus is cooled to a molten state. The mix of phosphorus and
water (phossy water) and mud is then processed to recover the phosphorus. During this
process, another waste product, called slag, is generated. Typically, 90 percent of the
phosphate rock which goes into making elemental phosphorous comes out of the process as
waste (EPA85a). There are large inventories of slag stored at both currently operating and
closed elemental phosphorus plants. This inventory has been estimated to be on the order
of 200 to 400 million MT from production activities up to 1975 (CRC81).
The ferrophosphorus and CaSiO3 slag are the principal NORM waste products from
the production of elemental phosphorus, with mass balances showing that most radionuclides
are being carried through the process. Because of furnace processing, slag is a glassy-like
material containing the radionuclides in a vitrified matrix. Because of this physical property,
slag waste is believed to be less susceptible to the leaching of radionuclides. In addition, the
slag has a high carbonate content which also reduces radionuclide solubility (EPA85a).
However, the EPA's Report to Congress on Special Wastes (EPA90a) documents groundwater
contamination at several phosphate slag waste management sites. As discussed in Section
B-2-10
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2.4, concentrations of uranium, thorium, and radium in elemental phosphorus slag have been
measured as high as 50 pCi/g. However, because of the high temperatures involved, some
radionuclides are vaporized. For example, as much as 95 percent of the lead-210 and
polonium-210 has been observed in caldner stack releases (EPASla, EPASlb, EPA84) and
subject to NESHAPS (EPA89b).
2.3 PHOSPHOGYPSUM STACKS AND F.T.T!MFNTAL PHOSPHOROUS WASTES
2.3.1 VIH« ftf Waste Materials
Phosphogypsum and elemental phosphorus slag are the phosphate wastes of primary
interest in this NORM sector. Phosphate fertilizers are treated as a separate NORM sector
(see Section B.3) since they are not waste products, do contain elevated levels of
naturally-occurring radioactivity, and are widely applied over agricultural croplands.
Phosphogypsum (calcium sulfate) is the principal waste product from wet-process
phosphoric acid production. The phosphogypsum is transferred as a slurry to disposal areas.
These disposal areas, which are referred to as phosphogypsum stacks, are generally
constructed directly on virgin or mined-out land with little or no prior preparation of the land
surface (EPA88). Each phosphoric acid production facility may have one or more
phosphogypsum stacks. Phosphogypsum stacks range in size from 2 to 300 hectares (750
acres) and range in height from 3 to about 60 meters. In addition to their large sizes,
phosphogypsum stacks are characterized with other physical features. Large areas of the
stack are typically covered with water in ponds, beaches, and ditches. Such surface features
may cover large areas, up to 60 percent of the top section of the stack. Other surface features
include areas with loose or crumbling materials, access roads, thickly-crusted top areas, and
thinly-crusted stack sides.
A total of 63 stacks have been identified nationwide (EPA89a). Since most of the U.S.
phosphate ore production takes place in Florida, this state has the largest number of stacks.
The distribution of phosphogypsum stacks and their numbers are given in Table B.2-3. As
B-2-11
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Table B.2-3. Location and number of phosphogypsum stacks.
State
Arkansas
Florida
Idaho
Illinois
Iowa
Louisa""
Mississippi
Missouri
North Carolina
Texas
Utah
Wyoming
«/ 0
Total
Number of
Stacks
1
20
6
8
3
7
1
3
5
7
1
1
63
Oueratinff
0
1,343
117
40
0
505
101
0
51
61
0
182
2,400
(16)
(2)
(1)
(4)
(1)
(1)
(1)
(1)
(27)
Idle
0
146
17
117
0
63
0
0
148
30
0
0
521
(1)
(1)
(2)
(3)
(4)
(3)
(14)
Inactive
9
81
27
71
64
0
0
48
0
71
121
0
492
(1)
(3)
(3)
(5)
(3)
(3)
(3)
(1)
(22)
Average Stack
Area:
89 ha.
37 ha.
22 ha.
(a) Total base area is given first, in hectare (ha.), followed by the number of stacks
shown in parentheses (EPA89a).
B-2-12
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can be seen, the average stack base area is largest for operating stacks, being nearly 90
hectares. The average idle or inactive stack is smaller in size, 37 and 22 hectare,
respectively. The average height is approximately 20 meters (EPA89a).
*
The production of phosphogypsum is estimated by applying the rule of thumb of 4.5
MT of phosphogypsum per MT of P2O5 (GUI75). For illustrative purposes, the yearly
phosphate rock, phosphoric acid!, and phosphogypsum production rates (TFI89, TVA86) are
tabulated below for selected years since 1965.
Phosphate Rock Phosphoric Acid Phosphogypsum
Year (million MT) (million MT) (million MT)
1965 26.8 3.5 15.8
1970 35.1 5.2 23.4
1975 44.3 7.0 31.5
1980 54.4 9.8 44.1
1984 49.2 9.9 44.6
1985 44.8 8.9 40.1
1986 32.8 7.4 33.3
1987 35.7 8.1 36.5
1988 38.3 9.3 41.9
These years were selected because they capture the productive capacity of the phosphate
mining industry for the last 20 years. As can be seen, the yearly phosphogypsum production
has averaged nearly 40 million MT since 1984. The total phosphate waste volume generated
in the U.S. from 1910 to 1981 has been estimated at 7.7 billion metric tons (EPA85a). In
Central Florida, the phosphoric acid industry produces about 32 million MT of
phosphogypsum each year, with a current stockpile of nearly 400 million MT.
Since 1984, the U.S. annual production rate of phosphate rock has averaged at about
40 million MT (TFI89). Under the assumption that 8 percent of this quantity is used for the
production of elemental phosphorus, 3.2 million MT of phosphate rock are processed annually
in thermal plants (TVA86, EPA89a). Since the thermal process yields about 0.07 MT of
elemental phosphorous per MT of phosphate rock, approximately 3.0 million MT of slag were
generated yearly by all U.S. thermal plants. The annual average slag generation rate is
therefore estimated to be about 600 thousand MT per plant.
B-2-13
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The quantity of phosphate rock used in domestic elemental phosphorus production
actually decreased from 3.2 million MT in 1986 (DOI87) to less than 3 million MT in 1988.
In 1988, the total industry-wide production of elemental phosphorus by the five plants listed
in Table B.2-2 was 311,000 MT (EPA90a). The aggregate industry-wide generation of slag
by the five plants was approximately 2.6 million MT, yielding a facility average of about
526,000 MT per plant (EPA90a). The sector-wide ratio of metric tons of slag to metric ton
of elemental phosphorus was 8.4 in 1988.
The predominant management practices for this waste material include sale of the
slag for use as an aggregate in road and building construction material and storage or
disposal of the slag in waste piles. In 1988, the quantity of slag sent to disposal waste piles
at the five facilities ranged from none to more than 500,000 MT per facility, averaging
320,000 MT. As of 1989, stockpile areas at the five facilities ranged from 5 to 38 hectares
(12 to 95 acres) per facility. The total quantity of slag accumulated in these piles in 1988
ranged from 1.5 million MT to 21 million MT per facility (EPA90a).
The amount of slag produced annually by elemental phosphorus plants is small
compared to the amount of phosphogypsum produced annually by phosphoric acid plants.
Over 13 metric tons of phosphogypsum waste is produced for each metric ton of slag
produced. Thus the predominant waste for this sector is phosphogypsum.
2.3.2 Phosphogyps" q«d. S^gg Utilization
Since there are large quantities of phosphogypsum waste, the industry would like to
encourage the use of phosphogypsum in order to minimize the disposal problem. Currently,
phosphogypsum is being used in several commercial applications with additional research
being conducted by such groups as the Florida Institute of Phosphate Research (FEPR) in
order to identify new applications and expand existing ones. Current applications include:
1) as fertilizer (see Chapter B.3), 2) as conditioner for soils where peanuts and other crops
are grown, 3) as backfill for roadbed material, 4) as additives to concrete and concrete blocks,
and 5) thermal processing to produce sulphur (LLO85). Research is being done on the use
of phosphogypsum in ceramic products, as anti-skid aggregate, concrete aggregate, and soil
conditioners (EPA85a, LLO85). During 1988, a total of 1.1 million metric tons of gypsum
B-2-14
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were used as a soil conditioner and fertilizer (TVA* 3). Almost 20 percent of this gypsum was
from phosphogypsum stacks. Over 86 percent c " the gypsum was used in three states,
namely California, Georgia, and North Carolina. )ther states where significant quantities
of gypsum were used include Arizona, Florida, an i Virginia.
The use of phosphogypsum in Europe and Japan has been much more widespread
than in the U.S., due to the absence of low-cost nat ral gypsum and lack of long-term storage
space. These countries have used phosphogypsu i extensively in cement, wallboard, and
other building materials (LLO85). Phosphogypsuxc was used by a New Jersey-based company
that manufactured wallboard, partition block: and plaster for distribution in the
northeastern United States between 1935 to 1946 (FIT78).
Because of elevated levels of radionuclides the use of phosphogypsum, especially in
building construction materials, could result in el vated radiation exposures to members of
the general public. OHiordan et al. suggest that lose estimates generated to characterize
exposure from phosphogypsum wallboards are an >rder of magnitude lower than suggested
guidelines (ORI72). However, Fitzgerald and Sensintaffar (FIT78) indicate that the
assumptions used to model the exposures were pr bably not realistic, that previous studies
may have led to underestimations, and that furtl ;r evaluations are necessary to take into
account current building practices. It was also re ommended that a survey be conducted of
a statistically acceptable number of homes built v ith phosphogypsum materials.
A modular structure consisting of pre ast ferrocement-sandwich panels was
constructed as part of the FIPR's ongoing res arch to establish commercial uses for
phosphogypsum (CHA87). The ferrocement oanels were made using 50 percent
phosphogypsum, 25 percent cement, and 25 per ent fine aggregate. Radon levels were
measured inside the structure using the worst pos ible ventilation conditions by making the
structure as air-tight as possible. Measurements ere made using both track-etch detectors
and radon gas analyzers. Radon levels were notec to range from 2.9 to 5.6 pCi/L (averaging
4.1 pCi/L) using track-etch detectors and from 1.1 to 15.9 pCi/L (averaging 5.1 pCi/L) using
a radon gas analyzer. Diurnal variations of radon ivels were observed with maximum levels
occurring when the walls were at their lowest ter perature (CHA87).
B-2-15
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The Texas Department of Health has authorized the use of phosphogypsum mixed
with fly ash and/or cement as a base for roads, parking lots, and storage areas, or as
underground bedding for pipes and utility lines (ROE87). The environmental assessment
concludes that such non-domestic applications do not endanger public health. The State of
Florida is considering a similar action following a review, of such kinds of applications.
Phosphogypsum has been used, on a limited basis, in the manufacture of wallboard as well
as in the manufacture of building materials, such as cements, concrete blocks, and panels.
However, because of treatment processes, the final physical properties of phosphogypsum
renders it uncompetitive with natural gypsum (BRU80).
In Japan, phosphogypsum is used in the manufacture of cement, gypsum board, and
plasters (MIY80). All of the phosphogypsum is used since the Japanese do not have a source
of natural gypsum. With phosphogypsum being used in other countries, the EPA has
conducted a survey of such uses in both Europe and Japan to characterize the potential
radiation hazards associated with such uses (FIT78, LLO88). Radiation exposure estimates
were reported to range from 100 to 400 mRem/year when used in wallboards. The Europeans
are considering the introduction of building codes which would prohibit the use of materials
having more than 25 pCi/g; control the use of materials between 10 and 25 pCi/g; and omit
regulatory controls of materials with less than 10 pCi/g (LLO88).
The Florida Institute of Phosphate Research is currently studying the impact of
Ra-226 uptake in vegetables grown on reclaimed lands (FIP88). Based on a recent study of
radioactivity in foods grown in a reclaimed clay settling area, a hypothetical individual is
estimated to receive a dose of 0.3 mrem per year more than an individual obtaining food from
unmined
Most of these applications typically involve only small quantities of phosphogypsum.
It is not conceivable, within the foreseeable future, to expect a sudden increase in the use of
phosphogypsum in a wide array of commercial products or applications. The physical
properties of phosphogypsum make it uncompetitive with natural gypsum since the former
contains wastes and impurities. Suggestions have been proposed to modify the benefiriation
process to yield phosphogypsum with less impurities and improved properties making it a
more desirable construction material (MIY80, HAB86, MOI80). Phosphogypsum has to be
transported over long distances to gypsum manufacturing plants since such facilities are not
B-2-16
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typically located near market a eas. Other things being equal, the added transportation cost
makes phosphogypsum uncomp jtitive unless natural gypsum is also transported over similar
distances.
Slag waste from elem ntal phosphorous plants has been used in a variety of
applications, principally in Ida 10 and Montana. An evaluation completed by the EPA and
the Conference of Radiation Coi trol Program Directors has indicated that slag materials have
been put to a wide variety of a] plications (CRC81, EPA83). Most of these applications have
included using slag as an ag regate in concrete and asphalt. Other applications have
included the use of slag in rail oad ballasts, as casting material for highway structures, in
roadbed fill and as backfill, in road gravel, and as a stabilization material for stockyards.
Slag materials have also been extensively used in the construction of streets, sidewalks,
parking lots, playgrounds, schc >ls, homes, churches, and other public buildings. In Florida,
slag has been used on roofs anc in septic tank fields. It has also been used in manufacturing
rockwool insulation. Slag mi trials have also been proposed for use in manufacturing
ceramic tiles.
Because of elevated lev< s of radioactivity in elemental phosphorus slag, some states
are restricting its use for certe n applications. For example, as noted in Section 2.4.3, the
State of Idaho has prohibited t ie use of phosphorus slag as an aggregate in materials used
for building construction while still allowing its use in road construction.
2.3.3 Twenty-Y***"* Waste IT. /entory
Phosphogypsum
Various estimates can be made of the amount of phosphogypsum that may be
generated in the U.S. during he next 20 years. These estimates are based on different
assumptions about waste gene ation rates and lead to different conclusions regarding total
metric tons of phosphogypsun: waste that may be produced. The different estimates are
summarized in the following p ragraphs.
B-2-17
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The total amount of phosphogypsum generated in the U.S. from 1910 to 1981 was
estimated at 7.7 billion metric tons (MT) (CRC81). Since 1981, another 350 million MT of
phosphogypsum were added to this inventory. Based on current average production rates of
phosphoric acid (about 8.7 million MT per year), it is estimated that 783 million MT of
phosphogypsum will be produced in the U.S. during the next 20 years (EPA89a). The Central
Florida phosphate district alone will produce 640 million metric tons of phosphogypsum in
the next 20 years, assuming that 32 million MT of phosphogypsum will be produced each
year. By the year 2000, it is estimated that about one billion metric tons of phosphogypsum
waste will be stockpiled in Florida alone (CHA87).
As mentioned previously, there are currently 23 wet-process phosphoric acid plants
operating or on standby in the United States. A typical phosphoric acid plant is designed to
produce about 150,000 MT per year of P2O5 (DEV79). Since about 4.5 MT of gypsum are
produced for every ton of P2O5, this equates to a typical yearly production of 675,000 metric
tons of phosphogypsum waste. Therefore, a typical wet-process phosphoric acid plant would
generate 13.5 million metric tons of phosphogypsum in 20 years. If all 23 plants remain in
operation, about 311 million MT of phosphogypsum will be produced during the next 20
years.
An EPA report estimates that, for an average wet-process plant, 700 metric tons of
P2O5 is produced per day (EPA88). This equates to a total of 23 million metric tons of
phosphogypsum for the average plant, assuming that the plant operates 365 days per year
over a span of 20 years. Assuming that 23 plants remain operational, and production
remains steady for the next 20 years, the overall future phosphogypsum inventory will be 530
million metric tons.
According to a Teknekron report (TEK79), 2 million MT of phosphogypsum are
produced and stored per year at a generic phosphoric acid plant. This equates to a total
20-year production of 40 million MT of phosphogypsum waste. Again, assuming that 23
plants remain in operation, 920 million MT of phosphogypsum will be produced in 20 years.
Given the wide range of these estimates (from 310 to 910 million MT), it is difficult
to predict with a reasonable degree of assurance what the inventory of phosphogypsum will
be over the next 20 years. It should be noted that the estimates described in the above
B-2-18
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paragraphs incorporate underlying assumptions which cannot always be compared on a one
to one basis. Unknown variables include fluctuation in the demand for phosphoric acid,
uncertainty in the production of phosphogypsum, and the utilization of phosphogypsum in
a variety of applications, and others. There are, however, 'several important factors which
may significantly impact the demand for phosphoric acid in the U.S. The most important
factor includes the installation of additional productive capacity by foreign producers. In the
U.S., and especially in Florida, the phosphate industry is also competing against limited land
and water resources and a growing population. State governments are also imposing
additional environmental controls and regulations on the industry. Taken together, these
factors will tend to raise production costs, may cause the industry to relocate in other states,
move production overseas, or rely on imports.
For this risk assessment, the 20-year phosphogypsum inventory is based on an
average annual production rate of 40 million MT. As noted in Section 2.3.1, this is
approximately the average rate of phosphogypsum production for the years 1984 through
1988. Thus this production rate already reflects, to a certain extent, the influence of foreign
producers and the realignment of the U.S. industry to these competitive forces. The 20-year
phosphogypsum inventory is estimated to be 800 million metric tons. This inventory is in
addition to the 8 billion metric tons of phosphogypsum already stockpiled at stacks in the 12
states listed in Table B.2-3.
Slag
As was noted earlier, the annual average slag generation rate is on the order of 600
thousand MT per plant. For the purpose of this report, this estimate is used to calculate the
20-year slag inventory since this generation rate reflects current industry practices. As was
already discussed above, it is assumed that current practices reflect some of the major factors
which have regulated, within the past few years, the productive capacity and growth of the
industry. Assuming that the five elemental phosphorus plants currently operating continue
in operation, it is estimated that about 60 million MT of slag waste will be generated during
the next 20 years.
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Phosphoric add scale is assumed to be generated at the rate of about 6 m per year
(MAR88). No attempt is made to account for the fact that some of the scale waste is disposed
with phosphogypsum in a mixed or diluted form. Assuming that all 23 phosphoric and
facilities generate scale in equal amounts, the estimated 20-year inventory of this waste is
about 3,000 m3. This volume is very small compared to the volumes of phosphogypsum and
elemental phosphorus slag expected to be generated during this period.
2A RADIOLOGICAL PROPERTIES OF PHOSPHOGYPSUM AND SLAG
tions of Phosphoi
Uranium in phosphate ores found in the United States ranges in concentration from
7 to 100 pCi/g (DEV79), while thorium occurs at lower concentrations, between 0.1 to 0.6
pCi/g (BLJ88). Ions, such as U*4, Th*4, Na+2, and Mg*2 substitute for Ca+2 in francolite
[Ca^POj, CO3)3F] (GUI75). Because of this ion-exchange property, phosphate rock contains
appreciable quantities of uranium and thorium and their decay products. During the
beneficiation process, approximately 42 percent of the total radionuclides present in the ore
is retained in the marketable rock. The clay slime carries about 48 percent of the
radionuclides, and the remaining 10 percent is left in the sand tailings (GUI75). Florida clay
slime contains about 45 pCi/g radium-226 (EPA75). Examples of the distribution of the
radionuclides found in phosphate ores and their respective concentrations are shown in Table
B.2-4.
Phosphogypsum contains appreciable quantities of uranium and its decay products due
to the high uranium concentration in the phosphate rock. When the phosphate rock is
processed, via acidulation, there is a selective separation and concentration of radionuclides.
Most of the radium-226, about 80 percent, follows the phosphogypsum while about 86 percent
of the uranium and 70 percent of the thorium are found in the phosphoric acid (EPA88).
Typical radium concentrations in phosphogypsum stacks fall within a range of 11 to 35 pCi/g,
B-2-20
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Table B.2-4. Radionuclide concentrations in phosphate ores, phosphogypsum, and
slag<8)
Radionuclide Concentration
Material &
Location0** U-238 U-234 Th-210
Phosphate ore
1: 27 26 39
2: 2.7 2.7 3.6
3: 43 44 38
4:
5: 32
6: 21
Slag
1: 26 26 50
3: 11 11 22
4:
7: 41 40 35
8: 21 20 20
Ferrophosphorous
1: 11 8.6 0.51
3: 9.7 9.8 0.05
4:
Gypsum(c>
9: 6.0 6.2 13
Ra-226 Pb-210 Po-210 Th-232
26 38 36 0.26
3.1 4.2 4.1 0.82
50 50 60 0.07
60
150 91
26 21
30 0.9 0.93
12 1.5 0.8 0.87
56
48 0.5
28 0.77
0.37 0.73 0.08
0.19 3.9 1.0 0.12
1.2
33 26.4 26.4 0.27
Th-228
0.52
1.1
0.13
0.25
1.1
0.08
0.21
1.4
(a) Data extracted from EPASla, EPASlb, EPA75, EPA88, EPA84, and EPA83.
(b) Location codes:
1: Stauffer plant, Montana.
2: Monsanto plant, local ore, Tennessee.
3: Monsanto plant, Florida ore, Tennessee.
4: Florida plants, average.
5: Monsanto plant, Idaho.
6: FMC plant, Idaho.
7: Idaho slag.
8: Montana slag.
9: Florida phosphate and plants.
(c) Concentration of Pc-210 and Po-210 are based on a radon emanation coefficient of 20%.
B-2-21
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with radium decay products falling also in the same range (HEN88, EPA85b, EPA88, LJN78).
Some examples of the distribution of the radionuclides found in phosphogypsum and their
respective concentrations are also shown in Table B.2-4.
Ferrophosphorus and slag are the principal waste products which carry most of the
radionuclides through the elemental phosphorus production process. Because of the high
temperatures involved in the process, slag is a vitrified material which binds non-volatile
radionuclides. Radionuclides with typically elevated concentrations include uranium and
thorium and their decay products. For example, elemental phosphorus slag has been found
to contain uranium and thorium in concentrations within the range of 20 to 30 pCi/g and
radium-226 in concentrations within the range of 30 to 40 pCi/g (EPA85b, HEN88). Company
responses to the EPA's 1989 National Survey of Solid Wastes from Mineral Processing
Facilities indicated that concentrations of uranium and thorium in slag range from 23 to
50 pCi/g in plants in Montana and Idaho, and from 2.4 to 45 pCi/g in plants in Tennessee
(EPA90b). This same national survey indicated that concentrations of Ra-226 in phosphorus
slag ranged from 4 to 32 pCi/g for plants in Idaho and Montana and from 3.2 to 27 pCi/g for
plants in Tennessee. Because of the high temperatures involved, some radionuclides are
vaporized during the production process. For example, as much as 95 percent of the Pb-210
and Po-210 have been observed in calciner stack releases (EPASla, EPASlb). Some examples
of the distribution of the radionuclides found in ferrophosphorus and slag materials from
elemental phosphorus production, and of the concentrations of these radionuclides, are shown
in Table B.2-4.
For this risk assessment, the reference waste form is assumed to be phosphogypsum,
and the assumed radionuclide concentrations are those considered to be typical of
phosphogypsum wastes. Radionuclide concentrations are not adjusted for the presence of slag
or phosphoric acid scale wastes. There are several reasons for this. One is that
phosphogypsum concentrations are rather conservative since it has been noted that some
phosphate ores, and consequently phosphogypsum materials, have lower radionuclide
concentrations than those shown in Table B.2-4. The volume of elemental phosphorous slag
is also much smaller than that of phosphogypsum. In general, the difference in radionuclide
concentrations between phosphogypsum and slag materials is small. Although some
measured concentrations of uranium and thorium are higher in phosphate slag than they are
in phosphogypsum, measured radium concentrations tend to be about the same. As shown
B-2-22
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in Chapter D, the dominant risks to workers and members of the CPG are from radon
inhalation, hence the radium concentration is of most concern in the evaluation of health
effects.
Because the volume of phosphoric acid scale is small, and because this material is
either stored or mixed with phosphogypsum rather than disposed of, this waste stream is not
included in this assessment. Some phosphoric acid operations result in scales with
significantly higher radionuclide concentrations than those in typical phosphogypsum wastes.
The main effect of these higher concentrations would be to increase the radiation exposures
to workers. Characterization of these scales and evaluation of associated radiation doses to
workers is beyond the scope of this report.
In view of these limitations, the following radionuclide concentrations are assumed for
this risk assessment:
Radionuclide Concentration (pCi/g)
Po-210 26.4
Pb-210 26.4
Ra-226 33.0
Th-228 0.27
Ra-228 0.27
Th-230 13.0
Th-232 0.27
U-234 6.2
U-235 0.3
U-238 6.0
Po-210 and Pb-210 concentrations are derived by applying a radon emanation coefficient of
0.2, assuming that the radionuclides are retained in the phosphogypsum (EPA75). The U-235
concentration is assumed to be 5 percent that of the U-238.
2.4.2 Radon Fh« Rates
The radon emanation rate from phosphogypsum stacks is known to be highly variable
and depends primarily upon such factors as uranium (and radium) concentrations in
phosphate rock, emanation fraction, vegetation cover, porosity, moisture content, presence
of standing water, temperature, and barometric pressure. Average radon emanation rates
B-2-23
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have been reported to vary from 1.7 to 12 pCi/m2-s, with a mean value of 6.8 pCi/m2-s
(EPA89a). The emanation rate, based on measurements made on loose and dry materials,
varies even more significantly, ranging from 0.2 to 340 pCi/m2-s (EPA89a, ROE85). Given
that phosphogypsum stacks, include surface features such as ponds, ditches, and beaches, the
radon exhalation rates over these features is known to be significantly less when compared
to loose or dry tnate^al*- Radon emanation rates as low as 0.5 pCi/xn -s have been noted on
beaches. Radon measurements made over ponds and large bodies of standing water have
revealed that radon emanation is essentially insignificant (NCR85, EPA89a). The
distribution of phosphogypsum stacks surface features is typically comprised, based on
surface area, of: ponds and ditches (60 percent), beaches (15 percent), dry and loose materials
(20 percent), and roads (5 percent). Applying these values, an effective radon emanation rate
of 5.0 pCi/m2-s is derived for a typical stack.
Radon *»ma«pti
-------
2.4.3 External Exposure Rates
Radiation surveys conducted on and near phosphogypsum stacks have indicated that
elevated radiation levels exist when compared to ambient background exposure rates. For
example, measurements made on the top of phosphogypsum piles revealed exposure rates
averaging 33 uR/h (TEX78, HOR88). Radiation surveys conducted in areas where large
volumes of phosphate ores are stockpiled have revealed exposure rates ranging from 20 to
100 uR/h, with an average of 60 uR/h (TEX78). Typical ambient exposure rates due to
background radiation varies from 5 to 10 uR/h in Florida (HOR88).
Radiation surveys conducted in Montana and Idaho, where large quantities of slag from
elemental phosphorous plants were used to pave streets and incorporated as building
materials, have also revealed the presence of elevated exposure rates. Ambient radiation
levels in streets paved with slag have been noted to vary from 28 to 50 uR/h (EPA83). In
homes, radiation levels as high as 65 uR/h have been noted while measurements made in a
church revealed exposure rates as high as 100 uR/h (EPA83, CRC81). Ambient background
radiation levels in both states are known to range from 13 to 19 uR/h in areas where it is
known that phosphate slags have not been used.
During 1986 and 1987, the EPA conducted a study (EPA90b) to evaluate gamma ray
exposures, and the attendant risks, to the populations of Pocatello and Soda Springs, Idaho
from the use of elemental phosphorus waste in the construction of roads and buildings. The
elemental phosphorus industry in southeast Idaho is about 40 years old. Radioactive slag
from plants in Pocatello and Soda Springs has been used as an additive in materials for
paving streets and constructing building foundations. In Pocatello, this slag was repeatedly
used in paving streets, while in Soda Springs the slag was used in some home foundations.
Due to concerns over radiation exposure, the State of Idaho has prohibited the use of
phosphorus slag in the construction of habitable structures since 1977, although slag is still
used as an aggregate in road construction (EPA90a).
Aerial and ground surveys were conducted at both Pocatello and Soda Springs during
1986 and 1987 to evaluate gamma ray exposures resulting from the use of phosphate slag.
A basic set of exposure scenarios was developed and used for both Pocatello and Soda Springs
to estimate time spent by individuals of different age groups in different exposure
B-2-25
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environments, including time spent inside and outside the home, in the general vicinity of
the home, and in the community as a whole. Exposure rates observed at locations included
in each scenario were multiplied by the corresponding scenario time intervals, and the results
were combined to generate total exposures for individuals in each age group.
The results of this dose and risk assessment are shown in Table B.2-5 for both the
average individual and the maximally exposed individual. Exposure to outdoor sources was
determined to be the greatest contributor to individual and population doses in Pocatello, due
to slag used in street paving. For Pocatello, the net gamma ray doses (the doses with an
average background of 12 uR/hr subtracted) were calculated to be 14 mrem/yr to the average
individual and 145 mrem/yr to the maximally exposed individual. These doses were
estimated to correspond to lifetime risks of 0.0004 to the average individual 0.004 to the
maximally exposed individual, based on 70 years of exposure.
Indoor exposure, resulting from slag in home foundations, was determined to be the
greatest contributor to individual and population doses in Soda Springs, Idaho. For Soda
Springs, the net gamma-ray doses were calculated to be 52 mrem/yr to the average individual
and 205 mrem/yr to the maximally exposed individual. These doses were estimated to
correspond to lifetime risks of 0.0014 and 0.0056 to the average and maximally exposed
individuals, respectively.
The EPA has noted that the risk estimates presented in the Idaho Radionuclide Study
may actually be a factor of two too low (EPASOb). In December 1989, the National Research
Council published its Biological Effects of Ionizing Radiation, or BEIR5, Report that offers
new risk estimates from radiation exposure. These new risk factors are about twice the risk
factors used in the Pocatello and Soda Springs study.
B-2-26
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Table B.2-5. Summary of dose and risk results from the Idaho
radionuclide exposure study (Source: EPA90b).
Annual
Individual Dose Lifetime
Community (mrem/vr) Risk* *
Pocatello
Average Individual 14 0.0004
Maximally Exposed Individual 145 0.004
Soda Springs
Average Individual 52 0.0014
Maximally Exposed Individual 205 0.006
(a) Lifetime risk values represent the probabilities of contracting a fatal cancer
assuming the individuals remain in their respective communities throughout their
entire 70-year lifetime.
B-2-27
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2.5 GENERIC SITE PARAMETERS AND SECTOR SUMMARY
2.5.1 Generic
The size of the generic phosphogypsum stack is based on data for phosphogypsum
production in the State of Florida since, as noted earlier, this state is the major producer of
phosphogypsum in the U.S. As shown in Table B.2-3, 20 of the 63 stacks either currently
active or idle in the U.S. are located in Florida.
According to Chang, the Central Florida mining district produces 32 million metric tons
of phosphogypsum waste per year (CHA87). Currently, there are over 400 million metric tons
stockpiled in this district and it is projected that another 640 million MT will be generated
during the next 20 years, bringing the total to 1.0 billion MT in Florida alone. However, this
estimate does not attempt to account for past and present utilization as well as mined out
areas that have been reclaimed. The total current and past utilization rates are unknown,
but are probably small. It is assumed that utilization amounts are negligible when compared
to the level of uncertainty associated with the data.
It is assumed that the generic site, over its operational life, will share its burden with
the total phosphogypsum inventory ever produced in Florida, including the estimated
inventory for the next twenty years. As noted, this total inventory is just over 1 billion
metric tons. Assuming that the existing 20 Florida sites will remain active or idle and not
be subjected to future reclamation, the average site will have a stockpile of about 50 million
MT of phosphogypsum. Given this inventory, the volume of the stockpile is 21.3 million cubic
meters, assuming a phosphogypsum density of 2.35 g/cm3. The resulting dimensions of such
a phosphogypsum stack are just under 1,750 m by 1,750 m, based on a 7 m height. The
exposed area of such a stack is about 3.0 million m2.
B-2-28
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2.5.2 Population Exposure
This generic phosphogypsum stack is assumed to be located in central Florida. The
population in this area is based on the state's average population density, or 216 persons per
square mile (BOC87).
2.5.3 Radionuclide Concentrations
The phosphogypsum radionuclide concentrations, as previously characterized, are used
as a basis of the radiological risk assessment. The radionuclide concentrations are not
adjusted for the presence of slag. The reason for this approach is the belief that
phosphogypsum concentrations are rather conservative since it has been noted that some
phosphate ores, and consequently phosphogypsum materials, have radionuclide
concentrations that are lower than those shown in Table B.2-4. Finally, the difference in
radionuclide concentrations between phosphogypsum and slag materials is not great so that
this disparity is not anticipated to skew the results of the risk assessment. These variations
are also within the range of uncertainty associated with the data characterizing these waste
forms. The reference radionuclide concentrations used in the phosphate waste risk
assessment of Chapter D are given in Section 2.4.1.
B-2-29
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B.2
ICES
BLI88 Bliss, Wayne A., Las Vegas Facility, Memorandum to Mr. H. Michael Mardis,
Environmental Protection Agency, Washington, DC, February 3, 1988.
BOC87 Bureau of Census, Statistical Abstract of the United States - 1988, 108th
Edition, Department of Commerce, Washington, DC, 1987.
BOM88 Bureau of Mines, World Demand for Fertilizer Nutrients for Agriculture, Open
File Report, OFR 24-88, Department of the Interior, Washington, DC, April
1988.
BRU80 Bruce, R.B., et al., Gypsum Building Products in North America: Can
Phosphogypsum Compete with Alternatives?, Proceedings of the International
Symposium on Phosphogypsum, Lake Buena Vista, Florida, November 5-7,
1980, p.89.
CHA87 Chang, W.F., Reclamation, Reconstruction, and Reuse of Phosphogypsum for
Building Materials, Florida Institute of Phosphate Research, Publication
No. 01-014-048, 1987.
CRC81 Conference of Radiation Control Program Directors, Natural Radioactivity
Contamination Problems, Report No.2, Frankfort, KY, August 1981.
DEV79 DeVoto, R.H., and D.N. Stevens, editors, Uraniferous Phosphate Resources and
Technology and Economics of Uranium Recovery from Phosphate Resources,
United States and Free World, Earth Sciences, Inc., Department of Energy
Open File Report GJBX-110(79), 3 volumes, 1979.
DOI87 Minerals Yearbook 1987, Volume 1, Metals and Minerals, Bureau of Mines,
U.S. Department of Interior, Washington, DC, 1987.
EPA75 Radioactivity Distribution in Phosphate Products, By-Products, Effluents, and
Wastes, Technical Note ORP/CSD-75-3, Office of Radiation Programs,
Environmental Protection Agency, Washington, DC, August 1975.
EPASla Emissions of Naturally Occurring Radioactivity from StaufFer Elemental
Phosphorus Plant, ORP/LV-81-4, EPA, Office of Radiation Programs, Las
Vegas, Nevada, August 1981.
EPASlb Emissions of Naturally Occurring Radioactivity from Monsanto Elemental
Phosphorus Plant, ORP/LV-81-5, EPA, Office of Radiation Programs, Las
Vegas, Nevada, August 1981.
EPA83 Environmental Protection Agency, Evaluation of Radon Sources and Phosphate
Slag in Butte Montana, Environmental Protection Agency, EPA 520/6-83-026,
Washington, DC, June 1983.
B-2-R-1
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EPA84 Environmental Protection Agency, Regula ory Impact Analysis of Emission
Standards for Emission Standards for Ele mental Phosphorus Plants, EPA,
Office of Radiation Programs, Washington DC, EPA 520/1-84-025, October
1984.
EPA85a Environmental Protection Agency, Repor to Congress, Wastes from the
Extraction and Benefitiation of Metallic 3res, Phosphate Rock, Asbestos,
Overburden from Uranium Mining, and Oil Shale, EPA/530-SW-85-033,
Washington, DC, 1985.
EPA85b Environmental Protection Agency, Radiat on Exposures and Health Risks
Associated with Alternative Methods of Land Disposal of Natural and
Accelerator-Produced Radioactive Material. (NARM) (DRAFT), Performed by
PEI Associates, Inc., and Rogers & Associe .es Engineering Corp. under EPA
Contract 68-02-3878, October 1985.
EPA88 Environmental Protection Agency, Bad ground Information Document,
Radionuclide Emissions from Phosphogyp mm Stacks, - Risk Assessment,
Washington, DC, 1988.
EPA89a Environmental Protection Agency, Draft Er. /ironmental Impact Statement for
Proposed NESHAPS for Radionudides-Ba :kground Information Document,
Volume 2 Environmental Protection Agency EPA 520/1-89-006-1, Washington,
DC, February 1989.
EPA89b Environmental Protection Agency, 40 CFR 6 ., National Emission Standards for
Hazardous Air Pollutants; Radionuclid s; Final Rule and Notice of
Reconsideration, Federal Register, Vol. 54 No. 240, December 15, 1989, pp
51654-51715.
EPA90a Environmental Protection Agency, Report t Congress on Special Wastes from
Mineral Processing, EPA/530-SW-90-07C:, Office of Solid Waste and
Emergency Response, Washington, DC, Jui' 1990.
EPA90b Environmental Protection Agency, Radiom elide Exposure Study - Pocatello
and Soda Springs, Idaho, Office of Radiat m Programs, Las Vegas Facility,
April 1990.
FIP88 Florida Institute of Phosphate Research, 19: 8 Annual Report, Bartow, Florida.
FIT78 Fitzgerald, J.E., and E.L. Sensintaffar, Rad ation Exposure from Construction
Materials Utilizing Byproduct Gypsum 1 om Phosphate Mining, Nuclear
Regulatory Commission, NUREG/CP-O 01, Radioactivity in Consumer
Products, Washington, DC, August 1978.
GUI75 Guimond, R.J., and S.T. Windham, Radio: ctivity Distribution in Phosphate
Products, By-products, Effluents, and W astes, Environmental Protection
Agency, Technical Note ORP/CSD-75-3, Wi shington, DC, August 1975.
B-2-R-2
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HAB86 Habashi, F., et al., The Hydrochloric Acid Route for Phosphate Rock, Journal
of Chem. Tech. Biotechnology, Vol. 38, pp. 115-126,1987.
HEN88 Hendricks, Donald W., NORM in Mineral Processing, Published in CRCPD
Publication 88-2,19th Annual National Conference on Radiation Control, May
18-21,1987, Boise, Idaho, Conference of Radiation Control Program Directors,
Frankfort, Kentucky, 1988.
HOR88 Horton, T.R., et al., A Study of Radon and Airborne Particulates at
Phosphogypsum Stacks in Central Florida, Environmental Protection Agency,
EPA 520/5-88-021,October 1988.
KEA88 Keaton, Harlan W., Naturally Occurring Radioactive Materials in the
Construction Industry and Current Building Codes, Published in CRCPD
Publication 88-2,19th Annual National Conference on Radiation Control, May
18-21,1987, Boise, Idaho. Conference of Radiation Control Program Directors,
Frankfort, Kentucky, 1988.
LIN78 Lindeken, C.L., and Coles, D.G., The Radium-226 Content of Agricultural
Gypsums, Nuclear Regulatory Commission, NUREG/CP-0001, Radioactivity in
Consumer Products, Washington, DC, August 1978.
LLO85 Lloyd, G. Michael, Jr., Phosphogypsum, A Review of the Florida Institute of
Phosphate Research Programs to Develop Uses for Phosphogypsum, 1985,
Bartow, Florida.
LLO88 Communication with Mr. Lloyd, G. Michael, Jr., Florida Institute of Phosphate
Research, Bartow, Florida, with SC&A, Inc. personnel, September 1988.
MAR88 Martel, Chris, telephone conversation with Arthur D. Little, Boston,
Massachusetts, on February 3, 1988.
MIY80 Miyamoto, M., Phosphogypsum in Japan, Proceedings of the International
Symposium on Phosphogypsum, Lake Buena Vista, Florida, November 5-7,
1980, p.573.
MOI80 Moisset, J., Radium Removal from Phosphogypsum, Proceedings of the
International Symposium on Phosphogypsum, Lake Buena Vista, Florida,
November 5-7,1980, p. 384.
NCR85 National Council on Radiation Protection and Measurements, Evaluation of
Occupational and Environmental Exposures to radon and Radon Daughters in
the United States, Report No. 78, Washington DC, May 1985.
ORI72 OTCordan, M.C., et al., The Radiological Implications of Using By-Product
Gypsum as a Building Material, National Radiological Protection Board,
Harwell, Didcot, Berks, the United Kingdom, Report NRPB-R7, 1972.
REL89 Relsch, M.S., Phosphorous Producers Enjoying Good Year, Chemical &
Engineering News, p. 13, July 17, 1989.
B-2-R-3
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ROE87 Roessler, C.E., The Radioactivity Aspects of Phosphogypsum, paper submitted
to the Proceedings of the Florida Natural Radiation/Technologically Enhanced
Natural Radiation Symposium, Daytona Beach, Florida, May 6-8, 1987.
ROE85 Roessler, C.E., Radon Emissions from Phosphogypsum Stacks, paper presented
at the Proceedings of the Eighteenth Midyear Topical Symposium of the Health
Physics Society, Colorado Springs, January 6-J.O, 1985.
TEK79 Teknekron Research, Inc., Information Base (Including Sources and Emission
Rates) for the Evaluation and Control of Radioactive Materials to Ambient Air,
Vol. 2., Interim Report, prepared for Office of Radiation Programs,
Environmental Protection Agency, Washington, DC, July 1979.
TEX78 Texas Instrument, Inc. Central Florida Phosphate Areawide Impact
Assessment, Program, Vol.VL Land, Report prepared for Environmental
Protection Agency, Dallas, TX, September 1989.
TFI89 The Fertilizer Institute, Fertilizer Facts and Figures, Washington, DC, 1989.
TVA88 Tennessee Valley Authority, Commercial Fertilizers, TVA/NFCD-85/5, Bulletin
Y-207, Muscle Shoals Alabama, December 1988.
TVA86 Tennessee Valley Authority, Fertilizer Trends, TVA/OACD-86/12, Bulletin
Y-195, Muscle Shoals Alabama, October 1986.
TWN88 Townsend, F.C., D.G. Bloomquist, S.A. McClimans, and M.C. McVay,
Reclamation of Phosphatic Clay Waste Ponds by Capping, Florida Institute of
Phosphate Research, Publication No. 02-030-056,1988, Bartow, Florida.
B-2-R-4
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B.3. PHOSPHATE FERTHJ ZERS
3. INTRODUCTION
As discussed in the preceding Chapter, phosphat rock is mined and processed to
pt .duce phosphate fertilizers. The major waste product is; hosphogypsum. The end product,
pi isphate fertilizers, while obviously not a wast*. contains elevated levels of
m -urally-occurring radioactivity. Fertilizers are availab e in three major physical forms,
hi .k, fluids, and bagged. About 80 percent of phosphate fertilizer consumption is handled
in a bulk form. Phosphate is also found in multiple-nutrii at fertilizers, which are available
in different blends of nitrogen (N), phosphate (P), and po assium (K), usually expressed in
v£ .-ying percentages of N-P-K.
Fertilizers are spread over large areas of agriculti ral land. The major crops which
arj routinely treated with phosphate based fertilizers in :lude coarse grains, wheat, corn,
so 'beans, and cotton. Since large quantities of fert lizers are used in agricultural
ap plications, phosphate fertilizers are included as & ^ ORM material because of their
pc ential for environmental contamination. The use of phc .phate fertilizers could eventually
le. d to an increase of radioactivity in the environment.
In the sections which follow, a description of types of phosphate fertilizers and their
ag -icultural applications are provided to charact ;rize the process by which
m :urally-occurring radionuclides are introduced into the t avironment. The description also
pr .-sents information on current and future phosphate fei .ilizer production and application
ra es. This information is used in Chapter D to assess pott atial exposures to members of the
pi blic and critical population groups from the use of phos phate fertilizers.
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3.2 PRODUCTION OF PHOSPHATE 1 'ERTILJZERS
3.2.1 Phosphoric Acid Production
The primary ingredient in the proc iction of phosphate fertilizers is phosphoric acid.
Typically, the phosphate fertilizer plant i . co-located with the phosphoric acid production
facility.
Phosphoric acid can be produced tr a wet process and a furnace process. In the wet
process, benefitiated phosphate ore is t: sated with sulfuric acid. The product of this
operation is a slurry that consists of the phosphoric acid solution and a suspended solid,
calcium sulfate, commonly known as phos )hogypsum. About 95 percent of the commercial
phosphoric acid produced by the wet prc :ess is used in the production of fertilizers and
animal feed, with a small portion used i s a feedstock in chemical processing operations
(BOM87). Furnace process phosphoric a< -d production uses elemental phosphorus rather
t-Vinn beneficiated phosphate rock as a fee istock. The major wastes from wet process and
furnace process phosphoric acid product on phosphogypsum and furnace slag are
described in Chapter B.2, and are, therefc ,-e, not considered further in this chapter.
Phosphoric acid production incre; ;ed steadily between 1965, when the industry
produced 3.5 million metric tons (MT), i id 1984, when 10.3 million MT were produced
(TVA86). After 1984, phosphoric acid proc action decreased to about 8.4 million MT per year
(TFI89), due to lower domestic demand fc fertilizer and reduced foreign buying. In 1988,
production increased slightly to 9.3 millic i MT (TFI89), boosted by a recovery in the farm
economy. The U.S. phosphoric acid ind .stry also competes on the world market. The
industry's share of the world market has s sadily decreased since 1984, when it exported 1.1
million MT, to 1988, when only 0.24 mill on MT of phosphoric acid was exported (TFI89).
Phosphoric acid production is tied strong / to domestic and foreign fertilizer consumption
rates. Non-fertilizer uses of phosphoric aa I have declined steadily since the early 1980*3 due
to strict regulations governing the use of p losphates in household products and a decline in
industrial demand (EPA90).
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3.2.2 Phosphate Fertilizer Production
Phosphate fertilizers are produced from phosphoi c acid and directly from phosphate
rock. Nearly all (more than 90 percent) of the phosphate fertilizers produced in the U.S. are
produced by a phosphoric acid process. Phosphoric .cid.can be combined with either
ammonia, potassium salts, or additional phosphate ore tt produce a variety of fertilizers that
include ammonium phosphates, superphosphates, and coi centrated liquid fertilizers (DEV79,
TVA86). Superphosphate, sometimes called super acid, is typically 70 percent phosphorus
oxide (P2O5) versus 50 percent for the normal grade (G f!88, TVAS6). The distributions of
nitrogen (N), phosphate (P), and potassium (K) in fertil sera vary, since there are over 100
multiple-nutrient fertilizer grades (TVA88a). For the fi rtilizer year ending in June 1988*,
the average phosphate contents in multiple-nutrient fe. dlizer blends were 12.1 percent in
N-P-K, 40.3 percent in N-P, and 15.1 percent in P-K (T A88a).
Some phosphate rock (apatite) is acidulated with i limited amount of sulfuric acid to
produce a solid product called normal superphosphate. Dry or bulk fertilizers made from
sulfuric acid acidulation are granulated for ease of hand ing. They are non-hygroscopic and
free-flowing, whereas nitrophosphate fertilizers must be coated. Normal superphosphate is
directly useable as a plant nutrient since the apatite ha . been reacted with acid to produce
water soluble phosphorus.
3.3 PHOSPHATE FERTILIZER CONSUMPTION
3.3.1 Constitution «»nd Application Rates
The United States is a major producer and consu. ler of phosphate fertilizers. As can
be seen from Tables B.2-1 and B.2-2 of Chapter B.2, maj< - locations for the production of wet
process phosphoric acid and elemental phosphorus ar the states of Florida and Idaho,
respectively. These states are also major producers of j hosphate fertilizers.
A fertilizer year runs from July to June.
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Actual and projected use of phosphate fertilizer in the U.S. is shown in Table B.3-1
(BOM88). The yearly demand was higher in the period from 1980 to 1985 than it was in
subsequent years because of a depression in the farm economy that resulted in a reduction
in crop acreage during the latter part of the decade. Demand for fertilizer is expected to
increase because of the recovery of the farm economy which resulted in an increase in crop
prices and planted acreage in 1989 (EPA90). The annual average U.S. demand for phosphate
fertilizers during the nine-year period, 1980 to 1988, was 4.8 million MT (BOM88).
The data reported in Table B.3-1 reflect the use of phosphate fertilizers on major
crops, such as coarse grain, wheat, soy beans, and cotton. Typically a third of the production
is used in the corn belt region (GUI88). As can be seen from Table B.3-1, the demand for
fertilizer closely parallels the acreage of major agricultural crop production. This acreage has
varied between 117 to 142 million hectares since 1980 (BOM88). The average over the past
nine years is 129 million hectares. The year to year variation in the productive agricultural
acreage is largely due to government programs and subsidies regarding grain production.
Farmers are at times encouraged not to grow certain crops and to keep land fallow. Fertilizer
application rates have, for obvious reasons, paralleled demand from year to year.
Phosphate fertilizer application rates, during the nine-year period 1980 to 1988, varied
from a low of 35 kg per hectare to a high of 41 kg per hectare. The average was 37 Kg per
hectare. As ***» be noted, the average application rate for this period is not significantly
different from projected application rates given for 1990 and 1995. For the sake of
comparison, other fertilizers are typically applied at higher rates. For example, nitrogen and
potash are applied at rates of 100 and 40 kg per hectare, respectively.
The demand for fertilizers varies by states across the U.S., with agricultural states
obviously using more fertilizers than others. During the 1987-1988 fertilizer year, 12 top
ranking states used nearly 60 percent of the total phosphate fertilizer consumption, as seen
in Table B.3-2. Illinois was the top ranking state, using 357 thousand metric tons (MT). As
can be noted, Illinois is, however, fourth in agricultural cropland area. In general, the top
12 states applied fertilizers at rates varying from 11 to 39 kg per hectare. The overall
average fertilizer application rate of these 12 states was essentially identical to that of the
national average, 25 versus 24 kg per hectare, respectively.
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Table B.3-1. Trends in phosphate fertilizer demand and application.(a)
- Year -
Actual/Proiected
Fertilizer
Demand
(million MT)
Major Crop(b)
Harvested Areas
(million Ha)
Application Rates
(Kg/Ha)
1980
1981
1982
1983
1984
1985
1986
1987
1988
1990
1995
Average of Actuals:
5.5
5.6
5.0
4.4
5.2
4.9
4.5
4.2
4.2
4.4
LO
4.8
134
142
136
120
131
134
126
117
120
125
135
129
41
39
37
37
40
37
35
35
35
35
37
37
(a) Data extracted from World Demand for Fertilizer Nutrients for Agriculture - 1988
(BOM88).
(b) Major crops include coarse grain, wheat, soybeans, and cotton.
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Table B.3-2. Phosphat - fertilizer consumption 1987-1988.(a>
Top 12
Ranking States
1-Dlinois
2-Iowa
3-Texas
4-Minnesota
5-Indiana
6-California
7-Nebraska
9-Ohio
10-Kansas
11-Wisconsin
12-Michigan
12 State Total:
U.S. Total:
Fertiliz. r
Consump ion
(thousand VTT)
Crop(b)
Land Area
(million Ha)
Estimated Rates
(Kg/Ha)
357
307
208
226
206
166
114
159
129
118
114
2,258
4,100
9.9
11.0
13.0
9.2
5.5
4.2
8.1
5.0
12.0
4.6
3.8
92.3
168.0
36
28
16
25
37
39
14
32
11
26
30
Average: 25
Average: 24
(a) Data extracted from Fertilize} Facts and Figures (TFI89).
(b) Crop land area obtained for St itistical Abstract of the united States -1988 (BOC87).
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Gypsum, including phosphogypsum, is also being used in increasing amounts to
fertili e and condition soils. During the 1987 and 1988 fertilizer years, 0.91 and 1.10
millio . MT of gypsum were used as a soil conditioner, primarily in the states of California,
Georg a, and North Carolina (TVA88a). It has been estimated that currently about 1.3
millio . MT of gypsum are used in agriculture in the U.S. each year (USG90). Of this
amou. t, approximately 220,000 MT (17 percent) is from phosphogypsum stacks. Gypsum is
used i i agriculture as a source of calcium and sulfur for crops such as peanuts grown in soils
that ; .-e deficient in these elements. Gypsum is also incorporated into soils to provide
sedim nt control for soils that have been eroded and leached to the point where they have
devel< oed a compacted crust. In addition, gypsum is sometimes incorporated into acidic soils
to act as a buffering agent. The application rate of gypsum (including phosphogypsum) is
highe than that of phosphate fertilizers, typically 2 metric tons per hectare (LIN80). When
used s a soil conditioner, gypsum is used at still higher rates, e.g., 20 metric tons per
hecta: 3 initially, followed with applications of 10 metric tons per hectare every other year.
Such ugh application rates are used in California where much of the Central Valley is
chara terized by arid and alkaline soils with high salt contents.
When phosphogypsum is used as the source of gypsum, it is sometimes palletized
before being applied to the soil; though the majority of phosphogypsum used for agricultural
purpc es is taken directly from disposal stacks, transported to local fertilizer companies, and
distri uted to the fanners. When the phosphogypsum is used as a fertilizer it is simply
sprea . on the top of the soil, whereas when it is used for pH adjustment or sediment control
it is t lied into the soil. As previously described in Chapter B.2, phosphogypsum contains
elevai 3d levels of radium, thorium, and uranium. Its repeated use as a fertilizer or soil
condr. oner can result in a significant increase in the concentration of these naturally
occur ing radionuclides in the soil. The potential magnitude of this increase is discussed in
Sectic i 3.4.1.
3.3.2 Twenty-Year Fertilizer Production Estimates
Compared to the other NORM sectors, the fertilizer industry obviously produces a
produ :t and not a waste. This product is generated in quantities which nearly match the
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demand. The industry also minimizes, for reasons of economics, the amount of fertilizer
which may be left in inventory stocks at the end of each fertilizer year. For this report, it is
assumed that production will simply match demand. As was noted earlier, the projected
demand is estimated to be about 5 million MT for the mid 1990s. Assuming that this
demand remains fairly constant over the next 20 years, the total production of phosphate
fertilizers will reach about 100 million MT over the next 20 years.
PROPERTIES OF FERTILIZERS
3.4.1 Radionuclide Concentrations
Phosphate rock contains elevated levels of uranium, radium, and other
naturally-occurring radionuclides. Typical concentrations of uranium and radium in Florida
phosphate rock are reported to be about 40 pCi/g (GUI88). Thorium is present at much lower
concentrations, typically less than 4.0 pCi/g. The phosphate fertilizer production process
causes most of the radium to remain with the phosphogypsum waste, while the majority of
the uranium and thorium remain with the phosphoric acid making up the fertilizer.
Radionuclide concentrations vary with the type of fertilizer and the production process, with
average concentrations ranging from 5 to 20 pCi/g for radium, 20 to 60 pCi/g for uranium,
and 1 to 5 pCi/g for thorium (EPA85, GUI88, SCA88).
The release of uranium and radium into the environment is appreciable due to the
large volumes of fertilizer used and the relatively high concentrations of naturally-occurring
radioactivity. Given U.S. fertilizer application rates and average radionuclide concentrations,
it is estimated that in 1984 about 30 curies of radium, 400 curies of uranium, and 10 curies
of thorium were introduced into agricultural croplands (GUI88). However, it should be noted
that despite high radionuclide concentrations and typical application rates, the incremental
presence of these radionuclides in natural soils is still low. It has been observed that the
incremental Ra-226 soil activity associated with fertilizer applications is about 0.25 percent
that of naturally-occurring radioactivity (UNS82). For example, assuming that 129 million
hectares are fertilized to a depth of 10 cm and that 30 curies of radium are introduced in the
B-3-8
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soil, the resulting incremental radium concentration is on the order of 0.0001 pCi/g. The total
soil concentration due to the three radionuclides noted above is on the order of 0.002 pCi/g,
assuming a one time application. By comparison, natural soils contain radium in
concentrations ranging from 0.1 to 3.0 pCi/g (NCR87).
Given the different grades (over 100) of fertilizers, it is difficult to identify a fertilizer
blend which would typify generic radiological properties. Different blends are obtained by
mixing various types of fertilizers, such as ammonium phosphate, normal superphosphate,
triple superphosphate, and phosphoric acid. Fertilizers also include other nutrients, such as
nitrogen and potassium. The actual radionuclide concentrations in typical agricultural
fertilizers are lower than those in phosphate fertilizers because of these other ingredients.
Typical radionuclide concentrations reported for the different phosphate fertilizers are:
Concentrations (pCi/g)
Fertilizer^ Ra-226 U-238 Th-230 Th-232
Normal superphosphate 21.3 20.1 18.9 0.6
Diammonium phosphate: 5.6 63 65 0.4
Triple superphosphate: 21 58 48 1.3
Monoammonium phosphate 5 55 50 1.7
Phosphoric acid0": 1 25.3 28.3 3.1
Gypsum: 33 6 13 0.3
(a) Extracted from NUREG/CP-0001 (GUI78).
(b) For acid at 28 percent.
Rather than assume a given blend of fertilizers, the radionuclide concentration is
pro-rated to the fertilizer production rate since it is assumed that production must at least
meet the demand. The production rates are those of 1988 for normal and triple
superphosphates, diammonium, and monoammonium phosphates (TVA88b). The
radionuclide concentrations are those characterized by Guixnond (GUI78), as shown
previously. For example, the average Ra-226 concentration is derived as follows:
B-3-9
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Phosphate Average Ra-226 Production(a)
Fertilizers Concentration (pCi/g) Rate (OOP tons)
Normal superphosphate: 21.3 1,660
Triple superphosphate: 21 1,660
Monof>TnTnnT"11TT1 phosphate: 5 7,240
phosphate: 5.6 7,240
(a) 1988 production in 1000 short tons.
Applying the average Ra-226 concentrations against the production rates, yields:
[21.3(1,660/17,800)] + [21.0(1,660/17,800)1 + [5.0 (7,240/17,800)]
+ [5.6(7,240/17,800)1 = 8.2 pCi/g.
Applying this methodology to the other radionuclides, gives the following fertilizer
concentrations:
___^___^_ Concentration
Radionuclide
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
Fertilizer
5.7
5.7
8.2
1.1
1.1
53.0
1.0
55.3
55.3
2.8
Soilw
0.0018
0.0018
0.0025
0.00034
0.00034
0.016
0.00031
0.017
0.017
0.00086
(a) Based on a phosphate application rate of 37 Kg/ha, plow depth of 15 cm, and applied for
20 years.
For Po-210 and Pb-210, it is assumed that the radon emanation coefficient is 0.3,
meaning that 70 percent of the decay products remain trapped in the material. It is also
assumed that U-235 is present at a concentration of 4.9 percent that of U-238 (GUI75). For
phosphoric acid and gypsum, it is assumed that the concentrations derived for the
B-3-10
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superphosphates (normal and triple) and ammonium phosphates (mono- and di-) are
encompassing since gypsum is used le s frequently and phosphoric acid is mostly used to
make these fertilizers rather than appl ed by itself.
Since fertilizers are widely sp -ead over large fields and diluted with soil, the
incremental radionuclide concentratioi s in soils are typically much lower than those for
fertilizer. Over time, the radionuclide t mcentrations are expected to build-up and reach an
equilibrium with competing removal me :hanisms that normally deplete fertilizers from soils.
These removal mechanisms include p int uptake, leaching by the infiltration of surface
water, and wind and water erosion. Th soil concentrations, as calculated above, assume an
application rate of 37 Kg per hectare, pplied yearly for 20 years. It can be seen that the
estimated resulting radionuclide cone ;ntrations are very low indeed. The actual soil
concentrations would probably be stL. lower, since these estimates do not account for
depletion mechanisms which tend to re nove radioactivity from the soil.
In a study of the impact of the i se of phosphogypsum as fertilizer (BUR76), data on
the radium-226 content of phosphogyp >um samples from Florida and Idaho were used to
calculate the increase in radium-226 coi tent of soil to which phosphogypsum is applied. The
study found that the application of 1 n: jtric ton of 40 pCi/g phosphogypsum to 1 hectare of
land, and mixed to a soil depth of 20 ci i, would increase the radium-226 content of the soil
by 0.0154 pCi/g. Therefore, the appli ation of phosphogypsum for the purpose of sulfur
fertilization, assuming an application IT .e of 2 metric tons per hectare per year (a typical rate
of fertilizer application, as discussed in Section 3.3.1) would result in an increase in the soil's
radium-226 content of 0.031 pCi/g-year The application of phosphogypsum for pH control,
assuming an average rate of 5 metric fo is per hectare per year (a typical rate of application
for pH control, as discussed in Sectic a 3.3.1) would result in an increase in the soil's
radium-226 content of 0.077 pCi/g-yeai Over a period of 20 years, these application rates
would cause radium-226 concentratioi s in the soil to increase by 0.62 and 1.54 pCi/g,
respectively, as compared to the typica radium-226 content in soils of 0.1 to 3.0 pCi/g.
This risk assessment is based or. fertilizer radionuclide concentrations in soils rather
than gypsum concentrations, since the ipplication of fertilizers to soils is more widespread
than the application of gypsum, except in some localized areas. Because of the limited use
of phosphogypsum as a soil conditioner, and the very widespread use of fertilizers containing
B-3-11
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phosphate, the risk from fertilizer application is considered to be limiting in terms of total
population health effects.
3*4.2 Radon Flux Rates
Radon emanation rates for phosphate fertilizer are assumed to reflect environmental
conditions of typical soils. For example, the NCRP notes that for typical soils the average
radon emanation rate is about 0.5 pCi/m2-s per pCi/g (NCR87). The U.S. Nuclear Regulatory
Commission cites radon emanation rates for tailings and soils with varying moisture
contents, based on work conducted by Tanner and Schiager (NRC80). The reported rates for
wet, moist, and dry materials are 0.35,0.65, and 1.2 pCi/m2-s per pCi/g, respectively. Given
that fertilizers are typically introduced into the top soil layer (10-15 cm), the moisture content
is expected to be lower, but not completely dry, when compared to soils at greater depths.
Soil moisture is removed primarily by evaporation and plant transpiration processes. Based
on these considerations and the above-noted radon emanation rates for conditions ranging
from moist to dry, a typical fertilizer radon exhalation rate may be on the order of about 1.0
pCi/m2-s per pCi/g in soils.
3*4.3 Radiation Exposure Rates
As was briefly noted above, the use of fertilizer may result in the movement and
transport of radioactivity in the environment. Radioactivity may be released with surface
water run-off and leaching, resulting in increased levels of radioactivity in lakes and rivers,
as has been noted in the Mississippi River water basin (GUI88). Leaching can also result in
contamination of ground water aquifers. Elevated levels of radioactivity have also been found
in drinking water wells (MOO88). Wind blown dispersion of soil and fertilizers can result in
releases of radioactive particulates in air, with subsequent exposures to downwind
populations. Radon gas released from the soil and fertilizers may also be carried downwind.
Direct external radiation exposures may occur from the fertilizer itself and in areas where
airborne deposition of wind blown material has occurred.
B-3-12
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Since food crops and animal feed are grown in fertilized soils, radionuclide plant
uptake may result from the ingestion of contaminated foods, although investigations have
shown that radionuclide intake from such pathways is generally minimal (EIS87, GUI88).
Given the application rates noted above, it would take several decades for radium to reach
an equilibrium concentration since removal mechanisms, such as surface runoff, downward
leaching or migration, and plant uptake, reduce the presence of radium (LIN80, ROE87). It
has been noted that these removal processes are in fact more effective since the limiting
factor is the presence of salt and not radium in fertilizers (LIN80). Plants have a limited
tolerance to salt and the soil would most likely not support plant growth long before the
radium concentration becomes critical to plant growth.
External radiation exposures associated with the application of phosphate or gypsum
fertilizers are expected to be very low when compared to ambient background levels. Given
that the mode of exposure, radionuclides, and source to receptor geometry are the same as
that found in environmental conditions, it can be assumed that the resulting radiation doses
can be simply scaled down based on empirically derived exposure rate conversion factors.
The conversion factors represent exposure rates for typical soils and include the effects of
gamma ray scatter, build-up, and self- absorption (NCR76). For example, the conversion
factors for the uranium and thorium decay series are 1.82 and 2.82 uR/h per pCi/g,
respectively (NCR76). As was noted above, the application of phosphate fertilizers results
in soil concentrations which are comparatively lower than that of natural soils. Assuming
respective U-238 and Th-232 concentrations of 0.128 and 0.002 pCi/g, the total incremental
exposure rate is estimated to be 0.24 uR/h. In the United States, ambient exposure rates due
to terrestrial radiation are known to range from 3 to 16 uR/h (NCR87).
B-3-13
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3.5 GENERIC SITE PARAMETERS AND SECTOR SUMMARY
3.5.1 Generic Agric^lfrp^al Site
The generic site for this NORM sector is assumed to be an agricultural field since
phosphate fertilizers are not stored in stacks or waste piles, but are distributed evenly over
vast agricultural croplands. The field is that of an average farm located in the state of
Illinois. As was noted earlier, this state uses the most fertilizers. The average size farm in
the state of Illinois is 136 hectares (340 acres) (BOC87). For the purpose of modelling ground
water infiltration and surface water runoff, it is assumed that the field is situated over an
aquifer and next to a surface stream. Assuming a square geometry, the dimensions of the
field are about 1,200 meters by 1,200 meters. The plow depth is assumed to be 15 cm. For
modelling external radiation exposures, the dimensions are assumed to be large enough such
that the source of exposure is due to an infinite plane source.
3.5.2 Population Exposure
The population density is assumed to be that of the state of Illinois, at 210 persons
per square mile (BOC87).
3.5.3 Radionuclide Concentrations
Several conservative assumptions have been made in this analysis for characterizing
the presence of naturally-occurring radionuclides in soils based on actual concentrations
found in most fertilizers. Radionuclide concentrations are estimated assuming repeated soil
applications for 100 years. The application rate is based on the higher application rate for
phosphate fertilizers. The resulting soil concentration has been estimated using current
practices. The radionuclide distribution and the respective radionuclide concentrations in
fertilizers and soils used in the phosphate fertilizer risk assessment of Chapter D are given
in Section 3.4.1.
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CHAPTERS
ICES
BOC87 Department of C mmerce, Statistical Abstract of the United States - 1988,
108th Edition, Bv reau of the Census, 1987.
BOM87 Bureau of Mines, .Minerals Yearbook, 1987 Edition, p. 676.
BOM88 Bureau of Mines, Vorld Demand for Fertilizer Nutrients for Agriculture, Open
File Report OFR 14-88, Department of the Interior, April 1988.
BUR76 Burau, R.G., Agr cultural Impact of Radium-226 in Gypsum Derived from
Phosphate Fertili er Manufacture, October 1976.
DEV79 DeVoto, R.H, and. Jtevens, D.N., Editors, Uraniferous Phosphate Resources and
Technology and E :onomics of Uranium Recovery from Phosphate Resources,
United States an i Free World, Earth Sciences, Inc., Department of Energy
Open File Report GJBX-110(79), 3 Volumes, 1979.
EIS87 Eisenbud, M., EC /ironmental Radioactivity, Third Edition, Academic Press,
Inc., Orlando, 19* 7.
EPA85 Environmental F otection Agency, Radiation Exposures and Health Risks
Associated with Alternative Methods of Land Disposal of Natural and
Accelerator-Produced Radioactive Materials (NORM) (DRAFT), performed by
PEI Associates, I: .c., and Rogers & Associates Engineering Corp. under EPA
Contract 68-02-3* 78, October 1985.
EPA90 Environmental Pi otection Agency, Report to Congress on Special Wastes from
Mineral Process: ag, EPA/530-SW-90-070C, Office of Solid Waste and
Emergency Respc rise, Washington, DC, July 1990.
GUI88 Guimond, R.J., and J.M. Hardin, Radioactivity Released from
Phosphate-Conta] rung Fertilizers and from Gypsum, Journal of Radiation
Physics and Cher .istry, Pergamon Press, New York, 1988.
GUI78 Guimond, R.J., Th 3 Radiological Aspects of Fertilizer Utilization, Radioactivity
in Consumer Pro lucts, NUREG/CP-0001, Nuclear Regulatory Commission,
Washington, DC, 1978.
GUI75 Guimond, R.J., aid S.T. Windham, Radioactivity Distribution in Phosphate
Products, By-Proc acts, Effluents, and Wastes, Technical Note ORP/CSD-75-3,
Environmental Pi otection Agency, August 1975, Washington, DC.
LJN80 Lindeken, C.L., R idiological Considerations of Phosphogypsum Utilization in
Agriculture, Proci.edings of the International Symposium on Phosphogypsum,
Lake Buena Viste, Florida, November 5-7, 1980.
B-3-R-1
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MOO88 Mooney, R.R., Department of Social and Health Services, Olympia,
Washington, Letter to Mr. Floyd Galpin, Environmental Protection Agency,
Washington, DC, February 3, 1988.
NCR87 National Council on Radiation Protection andMeasurements, Exposure of the
Population in the United States and Canada from Natural Background
Radiation, NCRP Report No. 94, Washington, JDC, December 1987.
NCR76 National Council on Radiation Protection and Measurements, Environmental
Radiation Measurements, NCRP Report No. 50, Washington, DC, December
1976.
NRC80 Nuclear Regulatory Commission, Final Generic Environmental Impact
Statement on Uranium Milling, NUREG-0706, Vol. HI, Washington, DC,
September 1980.
ROE87 Roessler, C.E., The Radioactivity Aspects of Phosphogypsum, Proceedings for
the Florida Natural Radiation/Technologically Enhanced Natural Radiation
Symposium, Daytona Beach Florida, May 6-8, 1987.
SCA88 Sanford Cohen & Associates, Inc., Technical Supplements for the Preliminary
Risk Assessment of Diffuse NORM Wastes, Prepared for U.S. EPA under
contract No. 68-02-4375, October, 1988.
TFI89 The Fertilizer Institute, Fertilizer Facts and Figures, 1989, Washington, DC.
TVA88a Tennessee Valley Authority, Commercial Fertilizers, TVA/NFDC-89/5, Bulletin
Y-207, Muscle Shoals, Alabama, December 1988.
TVA88b Tennessee Valley Authority, North American Fertilizers Capacity Data, Muscle
Shoals, Alabama, January 1988.
TVA86 Tennessee Valley Authority, Fertilizers Trends, TVA/OACD-86/12, Bulletin
Y-195, Muscle Shoals, Alabama, October 1986.
UNS82 United Nations Scientific Committee on the Effects of Atomic Radiation,
Sources, and Effects of Ionizing Radiation, 1982 report to the General
Assembly, United Nations, New York, 1982.
USG90 McElroy, C.J., Petition of the United States Gypsum Company for Partial
Reconsideration and Clarification, and Opposition of United States Gypsum
Company to the Petition for Partial Reconsideration and Request for Stay of
the Fertilizer Institute, United States Gypsum Company, February 9, 1990.
B-3-R-2
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B.4 FOSSIL FUELS-COAL ASH
4.1 INTRODUCTION
There are three major fossil fuels used by electric utilities and industry which have
the potential to generate NORM waste. These are coal, oil, and natural gas. Studies have
shown, however, that the naturally occurring radioactivity in oil and natural gas is very low
and that the radioactivity in the wastes produced by their combustion is negligible (NCR77,
BED70, EPA73, EPA89b). Therefore, this chapter only addresses coal ash. Combustion
wastes from oil and natural gas are not treated in this report.
About 700 million tons of coal were consumed in 1985 to produce electricity or steam,
and it is projected that by 1990 nearly 900 million tons will be consumed by electric utilities
and industrial boilers (EPA88). There are over 1,300 coal-fired boilers operated by electric
utilities and nearly 60,000 industrial boilers in the United States (EPA84, EPA89a, EPA89b).
Electric utilities consume the most coal. In 1987, coal was used to produce 57 percent of the
electrical needs of the United States. The balance of these needs were generated primarily
by nuclear power plants (18 percent), by oil and gas plants (15 percent), and by hydroelectric
plants (10 percent) (EIA88).
The consumption of coal generates large amounts of coal ash which require proper
management and disposal, either at the point of use or elsewhere in ash impoundment
facilities. Some of the ash may be put to productive use, for example, incorporated in
construction materials or used for land management and reclamation. Since coal contains
naturally-occurring radioactivity, large quantities of coal ash may present a potential
radiological risk to exposed individuals. The degree of risk will depend on the physical and
radiological properties of the ash and on whether the ash is disposed or used for some
purpose such as incorporation in building materials.
In the sections which follow, a description of coal-fired utility and industrial boilers
is provided to characterize ash generation and disposal practices for this NORM sector. The
description also presents data on the types and volumes of ash produced, the physical and
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radiological properties of ashes, future ash volumes and generation trends, and information
about the current and projected uses of ashes in various applications. This information is
used to assess potential exposures to members of the general public and the critical
population group. A radiological risk assessment is performed (see Chapter D) assuming that
the exposed population is residing near a generic coal ash site.
4.2 OVERVIEW OF COAL ASH GENERATION
4.2.1 CojQ-Fired. St«"*»»"-Electric Generating Stations
In a typical coal-fired boiler, coal is burned and the heat is extracted to generate
steam. A mixture of coal and air is introduced into the combustion chamber at the base of
the boiler and ignited. Depending upon the type of boiler, the combustion process may take
place in a state of suspension within the chamber or on a travelling bed. Simultaneously, in
the upper portion of the boiler, water is pumped through a series of tubes. Hot combustion
gases transfer heat to the water which leaves the boiler as high-pressure steam (about 2,000
psi) and at high-temperature (about 1,000 deg. F). The steam is used to drive a turbine,
which in turn, drives an electrical generator. Low pressure steam leaving the turbine is fed
to a cooling system which extracts any residual heat and condenses the steam back to water.
Condensed water is collected and recycled back to the boiler where the process is repeated.
The Electric generating capacity of coal-fired steam plants typically ranges from 100 to over
1,000 megawatts (thermal) (EPA84, EPA83).
The combustion process results in the generation of ash (about 10 percent of the
original volume of the coal) which is collected at the bottom of the boiler and in exhaust stack
niters. Nearly all of the ash (about 95 percent) is retained as bottom ash and boiler slag
(which together contribute 20 percent), or as fly ash (which contributes 75 percent) trapped
in exhaust stack filtration devices.
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4.2.2 Industrial Boilers
Industrial boilers are used mainly to produce process steam, generate electricity
(typically for the facility's own needs), and for space heating. Industrial boilers are used in
virtually every industry from small manufacturing to large, production facilities. As with
utility coal-fired plants, the consumption of coal is proportional to the size or capacity of the
boiler. Over 99 percent of the industrial boilers have a generating capacity of less than 75
megawatts (thermal) (EPA84). Given the varied distribution and application of industrial
boilers, three industries typically dominate the consumption of coal. These are the chemical,
paper, and metal fabrication (steel and aluminum) industries. These three industries
consumed nearly 90 percent of the total coal used by industrial boilers in 1974 (EPAS4).
4.3 COAL ASH GENERATION
4.3.1 Production of Coal Ash
Coal ash is formed when coal is burned in boilers that generate steam for power
production and in industrial boilers. The amount of ash that is produced depends on the
mineral content of the coal and the type of boiler. During the combustion process, some of
the ash is entrained with hot flue gases to form fly ash. The remainder of the ash, which is
too large or heavy to be entrained, settles to the bottom of the boiler to form bottom ash.
Liquid slag is formed when the ash melts under the intense heat. Modern furnaces that burn
pulverized coal generate more fly ash than stoker boilers because the combustion process
takes place in a state of suspension, rather than in a bed (EPA88, EPR88, EEI88). Eisenbud
estimates that furnaces burning pulverized coal release 70 percent to 85 percent of the coal
ash content as fly ash (EIS87). Stack filtration devices, such as electrostatic precipitators,
bag houses, and scrubbers are routinely used to reduce (typically by at least 95 percent) fly
ash emissions to the atmosphere. A small fraction of the fly ash, typically 2 percent to 5
percent of the total amount of fly ash produced, is released into the air.
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An estimate of the relative proportions of the different types of £ sh produced in
mod- rn furnaces tt it burn pulverized coal is:
Fly a h: 74 percent
Bottc n ash: 20 percent
Boile slag: 6 percent
The! s values, base I on 1984 data, are believed to be typical of the ash listribution for
curr atly operating furnaces and those that will operate for the next decad (EPA88).
The typical .atural content of minerals in coal used in the U.S. rai ges from about
3 pe cent to 30 pei :ent, with an average of about 10 percent depending u x>n the mining
regie i from which he coal originates (EPA88, ACA86a). Some utilities ai j selecting coal
with lower minera (or ash) content to meet particulate emission stand irds. In other
insti aces, utilities educe the ash content by washing the coal. Washing cai reduce the ash
cont at by as muci as 50 to 70 percent (EPA88). The 1985 representativ* ash content of
coali used by utilit es ranged from a low of 5.9 percent to as high as 29.4 percent, with a
nati< aal average of 10.5 percent. The average ash content of coal burned ha also decreased
steai ily since 197f from about 14 percent to the current value of 10.5 p jrcent (EPA88,
ACA 56a). The ash content has been predicted to remain at about 10 perce >.t until the end
of tt ; century (EPj 88).
Coal ash is < ategorized as Class F or C. Class F ash is generated by the combustion
of bi uminous coal vhile Class C ash is associated with lignite and sub-bi uminous coals.
Clas F ash is cha -acterized by higher amounts of silicon, aluminum, ire i, and a lesser
axno nt of calcium 'hen compared to Class C ash. Typically, these element? make up about
80 fo 90 percent of ill of the constituents of coal ash. The principal constitv mts of coal ash
are 1 sted in Table J.4-1.
Actual and p rejected ash production rates are shown in Table B.4-2. . is can be noted,
the early product on rate almost tripled between 1966 and 1987. The average yearly
prod iction rate, sir ze 1966, is 50.2 million metric tons. More recently, the average yearly
prod iction rate ove the past 10 years from 1977 to 1987, is 61.5 million M P. In 1987, the
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Table B.4-1. Constituents of coal ash.
(Source: ACA86a)
Typical Fraction (%)(b)
Constituents(a)
Silicon
Aluminum
Iron
Calcium
Sulfur
Potassium
Titanium
Magnesium
Sodium
Phosphorous
Bituminous
Class F
45.7
26.0
17.1
3.8
2.6
1.5
1.2
1.2
0.6
0.3
Sub-bituminous
Lignite
Class C
34.9
18.9
5.2
24.0
2.0
0.4
1.4
4.2
2.4
1.7
(a) Oxide form.
(b) Percentage for each constituent is rounded off.
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Table B.4-2. Actual and projected yearly ash (including fly ash,
bottom ash, and boiler slag) production rate.
Year of Production
Production Rate
Actual(a) Projected*1** (millions of MT)
1966 22.9
1967 25.0
1968 26.9
1969 28.8
1970 35.6
1971 38.9
1972 42.0
1973 44.7
1974 54.0
1975 54.4
1976 56.2
1977 61.5
1978 61.8
1979 68.2
1980 60.2
1981 62.0
1982 59.3
1983 57.9
1984 62.8
1985 59.1
1986 60.6
1987 62.5
1988 73.0
1989 75.0
1990 77.0
1995 90.0
2000 100.0
2005 110.0
2010 120.0
(a) Based on American Coal Ash Association, Inc. yearly data sheets for fly ash, bottom
ash, and boiler slags only.
(b) Projected rates are based on past trends (1966 to 1987) using linear regression. All
values are rounded off.
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combustion of coal in utility and industrial boilers generated 62.55 mil ion metric tons of coal
ash and slags and 12.89 million MT of sludges (ACA87a). The distribi; ;ion of ash and sludge
production (as rounded off) are as follows:
Ash Type Quantity*8*
Fly ash: 45.0
Bottom ash: 13.0
Boiler slag: 3.7
Sludges: 13.0
(a) In million metric tons.
Over the past 13 years, the yearly increase in ash general on has averaged 2.6
percent. This increase in ash production rate parallels the increa e in the demand for
electricity during the same period. The demand for electricity over th 3 period from 1973 to
1986 grew at an average annual rate of 2.5 percent per year (NER87 .
Although there is some uncertainty over the amount of coal 'hich will be used by
electric utilities, it is predicted that coal-fired power stations will si .11 produce the major
share of the nation's electrical capacity (EIA88). There are many facto 3 which can affect the
amount of coal consumed. Some factors include economic growi .1 rates, demand for
electricity, oil and gas prices, types of available technology, and reg- latory constraints on
waste disposal and airborne emissions. It is, however, reasonably pi -ident to assume that
utilities will continue to use coal and generate ash in large quantitit > into the foreseeable
future.
Long term projections predict that by the turn of the century, th yearly ash (including
bottom ash and boiler slags) generation rate will vary from 120 to 1. 0 million metric tons
(EPA88, EEI88). This report, however, predicts, based on current tn nds, that by the year
2000, the yearly generation rate will be about 100 million MT and re: ch 120 million MT by
about 2010 (see Table B.4-2).
The generation of ash is also known to vary by region through' ut the United States.
Based on an Electric Power Research Institute (EPRI) study, the du ;ribution of fly ash is
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predominantly governed by the number and size of coal-fired boilers located in each state.
Table B.4-3 presents the total quantity of fly ash produced from all states within the 9 EPRI
regions. As can be noted, in 1984 two regions (East North Central and South Atlantic)
generated over 40 percent of the fly ash produced nationwide (EPR88). To date, this
information is still deemed to be valid (MIL89). These two regions combined include a total
of 13 states. The total quantity of ash generated by region varies from a low of 0.25 million
MT in New England to a high of 11 million MT for the South Atlantic region. The average
per state, excluding Alaska and Hawaii is just under 1 million MT.
4.3.2 Coal Ash Disposal
The majority (typically 70 to 80 percent) of the coal ash produced is disposed in
impoundment and landfill facilities either on or ofisite (EPA88). The remainder is recycled
in a variety of commercial products or used by the ash producer for internal applications.
Ashes are usually placed into dry landfills or ash ponds. Sluiced ashes and flue gas
desulfurization sludges are stored temporarily in ponds for dewatering to be later transported
to a dry landfill. A typical ash disposal landfill may be anywhere from 30 to 60 hectares in
size (1 hectare is approximately 2.5 acres) (EEI88, EPA88). An ash pile of this size is
assumed to support the disposal needs of a modern power plant with a capacity that ranges
from about 500 MW (thermal) to 1,000 MW (thermal). The size of a disposal area can range
anywhere from 4 to 25 hectares with some facilities using disposal areas as large as 80
hectares. At the other extreme, one site was reported to have a landfill facility of 177
hectares (438 acres) (EPA88). In order to meet particulate emission standards, ashes are
generally disposed of in smaller areas or cells. Smaller active areas may use as much as 8
hectares and, on the average, are comprised of about 2 to 4 hectares (NOV89a). The depth
of the ash bed on closure may be as much as 9 m (30 ft) (EPA88).
The Edison Electric Institute indicates that, based on a 1989 survey, there are 305
off-site coal-ash landfills and surface impoundments (EEI89). It is also believed that there
are about 900 on-site disposal facilities. Of this total, the status of about 200 facilities is
uncertain as to its type, ownership, and whether or not such facilities are still active.
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Table B.4-3. Regional fly ash production and utilization-1984(a>
Fly Ash Produced
Flv Ash Utilized
EPRI Region
and States
Millions
ofMT
1. New England 0.254
ME, NH, VT, MA
CT, and RI.
2. Mid Atlantic
NY, PA, and NJ. 4.77
3. East North 8.99
Central
WI, MI, IL,
IN, and OH.
4. West North 4.87
Central
ND, MN, SD, NE,
LA, KS, and MO.
5. South Atlantic 11.0
DE, MD, VA, WV,
NC, SC, GA, and FL.
6. East South 4.80
Central
KY, TN, MS,
and AL.
7. West South 5.86
Central
OK, AR, TX,
and LA.
8. Mountain 4.61
MT, ID, WY, NV,
UT, CO, AZ,
andNM.
9. Pacific 1.36
WA, OR, and CA.
Totals: 46.5
Average per State: 0.97
Percent of
Total
0.5
10.3
19.3
10.5
23.7
10.3
12.6
9.9
2.9
100.0
Millions Percent
. MT Used
0.09
0.83
1.42
1.03
2.15
0.94
1.64
1.09
0.28
9.47
0.19
35.8
17.3
15.8
21.1
19.5
19.6
28.0
23.6
20.7
20.4%
(a) Extracted from EPRI CS-4446, March 1988 (EPR88).
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4.3.3 Coal Asb
During 1987, the coal ash industry reported that about 16.6 million MT of ash and 926
thousand MT of sludge were put to use into a variety of commercial applications. These
utilization rates represent 26.5 and 7.2 percent, respectively, of the total ash (all forms) and
sludge produced in 1987. A fraction of this quantity of ash was also used by the utilities for
site reclamation and land use management on utility property. The regional utilization of
Hy ash is given in Table B.4-3 based on 1984 data (EPR88). Table B.4-4 presents the 1987
utilization breakdown of ash, boiler slag, and sludge based on ash and sludge quantities given
above. On a regional basis, the utilization rates vary from a low of nearly 16 percent (East
North Central) to a high of about 36 percent (New England). The national average, based
on the 48 continental States, is 20.4 percent per state, representing about 0.2 million MT of
fly ash per state. This information is still valid although it is based on a 1984 survey
conducted by EPRI (MIL89).
A review of Table B.4-4 indicates that in terms of high volume utilization, the bulk
of the fly ash, bottom ash, and boiler slags are used as substitutes in cement and concrete,
structural fills, for snow and ice control, and as blasting grits and granules. Sludges are used
to manufacture wallboard, but the total volume used is minimal compared to the total
production. Ranked in decreasing order of utilization, the consumption or utilization of ashes
and sludges is distributed as follows:
Boiler slags 59.2 percent
Bottom ash 32.4 percent
Fly ash 22.0 percent
Sludges 7.2 percent
The coal ash industry (American Coal Ash Association), in a 1986 report, has indicated that
it foresees a broader range of applications and uses for ash (ACA86a). Such applications
include the use of greater volumes in existing applications as well as utilization in new and
emerging technologies (ACASTb, ACA88, BOR89, NOV89b).
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Table B.4-4. Ash and sludge utilization breakdown for 19* 7c)
ADDlication Flv Ash Bottom Ash Boiler Sla
: Sludge
External Markets:
-
-
-
-
-
-
-
-
-
(a)
(b)
(0
Cement/concrete 57.3
Structural fills 1.6
Road base and 2.2
subbase
Mineral filler 0.9
in asphalt
Snow and ice 0.05
control
Blasting grits 0.0
roof granules
Grouting 1.2
Coal mining 0.7
application
Wallboard 0.0
Miscellaneous 6.2
Subtotals (%): 70.1
Metric tons
(in millions): 7.0
16.9
4.8
3.5
0.1
11.8
0.7
0.0
7.8
10.0
6.9
4.9
1.7
1.9
1.6
8.0
64.6
0.0
0.0
0.0
2.1
52.4 84.8
2.3 1.9
Derived from, the American Coal Ash Association data sheet: 1987 (
Combustion By-product-Production and Consumption.
For fly ash, bottom ash, and slags, the total quantity used in 1987 v,
MT and 926 thousands MT for sludges.
Percentages and quantities may not add up to 100% or 16.6 million
rounding off.
0.07
0.09
0.0
0.0
0.0
0.0
0.0
0.0
15.3
1.9
17.3
0.16
oal
is 16.6 million
IT due to
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Table B.4-4. (Continued)
Utilization - Percent of Production(b>c)
ADDlication
Internal Utility Use:
. Cement/concrete
. Structural fills
- Road base and
subbase
- Snow and ice
control
. Miscellaneous
Subtotals (%):
Metric tons
(in millions):
Flv Ash
0.0
12.2
0.3
0.0
17.3
29.8
3.0
Bottom Ash
10.0
12.0
4.8
1.1
29.7
47.6
2.1
Boiler Slatr
0.0
0.1
0.6
2.8
11.7
15.2
0.34
Sludcre
0.0
0.0
3.4
0.0
79.3
82.7
0.77
Total by-product consumption by product category:
22.0 32.4 59.2 7.2
10.0 4.3 2.2 0.93
Total by-product consumption of fly ash, bottom ash, and boiler slags only:
In percent(%):
Metric tons
(in millions):
In percent(%):
Metric tons
(in millions):
16.6
(a) Derived from the American Coal Ash Association data sheet: 1987 Coal
Combustion By-product-Production and Consumption.
(b) For fly ash, bottom ash, and slags, the total quantity used in 1987 was 16.6 million
MT and 926 thousand MT for sludges.
(c) Percentages and quantities may not add up to 100% or to 16.6 million MT due to
rounding off.
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Fly ash has been used to replace the cement in concrete in the United States since
1910. Typically, fly ash is substituted for 10 to 30 percent of cement (EPR87, EPR88,
ACA86a). Depending upon the type of ash used, at ash concentrations greater than 30
percent, concrete may loose its desired strength and setting properties. In some applications
where physical strength is not mandatory, the ash content may be increased to as much as
50 percent depending upon the desired properties of such mixtures. Other related uses
include the manufacture of concrete construction blocks and preparation of grouting and
flowable fill mixtures.
Since the early 1970s, all three types of coal ash have been used in construction
projects. Coal ash is used to level out uneven terrain or applied as a stable fill for building
construction. Typical applications include sites where shopping malls, housing developments,
and industrial parks are planned for construction. Such projects have included the
construction of road embankments, runways, public transportation system structures, and
soil stabilization. In a 1984 newsletter, the American Coal Ash Association indicated that
40 States have already approved the use of coal ash in road construction and maintenance
projects (EPR88, ACA84a). Coal ash has also been used as an additive or filler for asphalt,
concrete, and for other aggregate materials. As an asphalt filler, fly ash can comprise up to
12 percent of the total mix.
Other applications include the use of coal ash as an ingredient in intermediate
materials used in the manufacture of finished products. Examples are the use of coal ash as
an ingredient in the manufacture of concrete blocks and its incorporation in lightweight
aggregate such as the granules in roofing felt. The use of coal ash in roofing felt granules
is currently limited since the manufacturing capacity is only emerging (ACA86a, ACA88).
Commercialization in the United States is under way and it is anticipated that at full
production, such plants will eventually be utilizing about 150,000 MT of fly ash per year.
In the examples noted above, coal ash is used directly as a construction material, e.g.,
as a substitute for natural materials. Other applications include: the use of a fly ash slurry
to extinguish fires in coal refuse piles and in deep mines; as flowable fill to stop and control
mine subsidence; as a cover to reclaim land strip mines for landfill operations; and, as a
solidification media to stabilize sludges and liquid wastes from municipal sewage treatment
and industrial facilities (ACA83, ACA88).
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For land reclamation, fly ash is typically blended with minin spoils at a rate of 200
to 400 MT per acre (EPR88). For soil amendment, where it is desir: ble to raise soil pH, fly
ash is added at a rate of 50 to 200 MT per acre and mixed to a so I depth of 15 to 30 cm
(ACA84b, ACA86b). Other direct applications include the use of boi. ;r slag and bottom ash
on icy and snowy winter roads to improve vehicular traction, grit for sandblasting, and pipe
bedding and backfill material.
Other emerging applications of fly ash include the constr ction and sinking of
artificial reefs, metal (aluminum and iron) extraction via direct ati< leaching, and filler in
paints and plastics. Examples of products which may contain fly sh include paints and
undercoatings, auto bodies and boat hulls, PVC pipes, battery cases bowling balls, utensils
and tool handles, vinyl floor covering, and shower stalls (ACA86a, AC V88). The use of fly ash
is also being tested and evaluated as a refractory for the steel indu try and as an additive
to explosives.
4.3.4 Twenty-year Coal Ash Inventory Estimates
The 20-year total ash volume is estimated using actual ash ger oration rates from 1966
to 1987 (Table B.4-2) and projecting the trend out to the year 201 >. Assuming that this
projection remains valid and that the distribution in the types of ash smains fairly constant,
the total ash volume which will be generated over the next 20 years s estimated to be 2,000
million MT. The breakdown between the different types of ash and oiler slag is as follows:
Ash Type Quantitv
-------
Using the 20-year projection with an assumed ash utilization rate of about 30 percent
(EPAS8), the total ash volume that could be put into productive use is about 600 million MT.
It should be noted that this estimate is subject to some variation. For example, past data
have indicated that ash utilization rates have typically varied by 10 to 20 percent from year
to year. Table B.4-5 presents actual coal ash utilization, rates from 1966 to 1987 and
projected rates from 1990 to 2010. If the past trend holds true, it is anticipated that by 1990
the utilization rate could be over 30 percent and possibly exceed 40 percent by the turn of the
century. These projections assume that the status quo will be maintained while following
a moderate growth rate. The utility industry and the American Coal Ash Association
(ACA88, EPR88, EEI88) are, however, forecasting higher utilization rates assuming that coal
ash will be used more widely in the near future. For example, the American Coal Ash
Association is estimating that the use of fly ash as a substitute in concrete could readily be
doubled by targeting large construction projects (ACA88, ACA86a). In terms of new
applications, fly ash (combined with lime) could be used to stabilize hazardous wastes. Other
potential applications involve construction projects or activities while assuming higher
utilization rates. Such applications include using ash as a base for road and highway
construction, as structural fills, and for land reclamation and soil amendments. Given the
potential range of applications which could readily be implemented, the American Coal
Association's ultimate objective is to reverse the current disposal (80 percent) and utilization
(20 percent) distribution to 80 percent utilization and 20 percent disposal (BOR89). It should
be noted that such a high utilization rate is technically achievable since in Europe high
utilization rates (70 percent) are not uncommon (ACA84c). On a local basis, some utilities
can achieve utilization rates as high as 80 percent, but such demands are typically met by
stockpiling ash over several years in anticipation of future needs or even "mining" closed ash
impoundment or landfill sites (ACA84d, BOR89, NOV89b).
The EPA, in its 1988 Report to Congress, concluded that a utilization rate of about 30
percent is realistic (EPA88). The EPA has also indicated that it encourages the utilization
of coal combustion wastes as one method to reduce the amount of waste which would
otherwise require disposal. Given current practices, the Agency also acknowledges that
existing utilization practices appear to be done in an environmentally safe manner.
Furthermore, it also noted that coal combustion waste streams generally do not exhibit
hazardous characteristics under RCRA regulations. The Agency also indicated that it did not
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Table B.4-5. Actual and projected yearly ash utilization rate.
Year of Production
Utilization Rate
Actual(a) Proiected(b) Percent of Production
1966 12.1
1967 13.5
1968 17.6
1969 15.3
1970 13.0
1971 20.1
1972 16.3
1973 16.3
1974 14.6
1975 16.4
1976 20.0
1977 20.7
1978 24.1
1979 21.0
1980 18.7
1981 24.0
1982 20.7
1983 20.0
1984 23.1
1985 27.4
1986 21.7
1987 26.5
1990 21-33
1995 23-36
2000 25-39
2005 27-43
2010 29-46
(a) Based on American Coal Ash Association yearly data sheets from 1966 to 1987 for
fly ash, bottom ash, and boiler slags.
(b) Projected rates are based on past trends (1966 to 1987) using linear regression.
Range is based on a fluctuation of 22% (or one standard deviation) from year to
year over the period of 1966 to 1987. All values are rounded off.
B-4-16
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intend to regulate, under RCRA Subtitle C, the disposal of fly ash, bottom ash, boiler slag,
and flue gas desulfurization wastes.
The EPA position, which encourages the utilization of coal combustion wastes, would
tend to promote the recycling of such materials in greater quantities and in more diverse
applications. Nevertheless, utilities, distributors, and other potential users are concerned
that fly ash and its use could become regulated in the near future. Conceivably, legislation
or regulations could be enacted which might severely limit the use of coal ash for commercial
applications. Such regulations could also leave users open to future litigations. In this
context, facilities or sites in which coal ash was once introduced could now be subject to
reclamation and clean up requirements (BOY89). Given these competing factors, it is difficult
to predict, with any accuracy, future trends in coal ash utilization. Some factors may cause
new markets and applications to appear while others may become suppressed or even
disappear. These factors, taken together, tend to favor the status quo and maintain a
limited, but relatively stable range of applications which tend to throttle high or spurious
growth rates (BOY89, CAI89). In view of these uncertainties, a 30 percent utilization factor
is assumed for this report.
4.4
4.4.1 Radionuclide Concentrations
Coal contains naturally-occurring uranium and thorium, as well as their radioactive
decay products. The radioactivity of coal is known to vary over two orders of magnitude
depending upon the type of coal and the region from which it has been mined (EPA84, EIS87,
BED70, UNS82). The concentrations of U-238 and Th-232 in coal can range from 0.08 to 14
pCi/g and 0.08 to 9 pCi/g, respectively (UNS82). In a review of 800 coal samples
characterizing U-238 concentrations, Wagner and Greiner noted that only 0.5 percent of the
samples exceeded an activity of 10 pCi/g (WAG82). Beck conducted an evaluation of nearly
1,000 U.S. coal samples and reported average (arithmetic) U-238 and Th-232 concentrations
of 0.6 and 0.5 pCi/g, respectively (BEC80, BEC89). The frequency distribution of measured
B-4-17
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U and Th contents in coal, however, indicates that concentre ions (based on geometric mean)
are in fact predominantly lower. For example, the reported nean geometric concentrations
of U-238 and Th-232 are 0.34 and 0.26 pCi/g, respectively ( EC80).
The concentration of U-235 in coal is much lower tl an the concentration of U-238.
The natural abundance of the U-235 isotope in natural urai .um is 0.72 percent. Assuming
that the relative abundance of U-235 to U-238 in coal h: ; this same value, and taking
account of the differences in decay rate between U-235 and '-238, for each 1 pCi/g of U-238
in coal there should be about 0.05 pCi/g of U-235.
The radionuclide distributions and concentrations in :oal ash are also known to vary
significantly (UNS82, BED70, EPA85, EPA83, GRE87). F >r example, U-238 and Th-232
concentrations have been noted to range from 1.5 to 8 i pCi/g and 0.4 to 7.5 pCi/g,
respectively (BEC89, BEC80). Average concentrations of I 238 and Th-232 in fly ash are
reported to be about 5.4 and 1.9 pCi/g, respectively (UNS82 The radioactivity of fly ash is,
therefore, typically higher than that of coal. This enrichme t is dependent upon the type of
coal used, its ash content, and the type of boiler in whi .1 coal is used (UNS82). The
enrichment ratio also varies depending upon the elements form of the radionuclide. For
example, enrichment ratios of about 1.3 and 1.4 have been eported for U-238 and Th-232,
respectively (UNS82). For other nuclides, much higher enrichment ratios have been
observed; up to 2 for Ra-226 and between 5 to 11 for Po-21' and Pb-210. Typically, higher
ratios characterize escaping fly ash rather than collected fl ash.
Because of the disparate nature of the data regarding the presence and concentration
of radionuclides in ash materials, a simplified approach as used in this assessment to
estimate ash concentrations for uranium and thorium, indu ing their decay products. First
a limited review of the published literature was conductec to identify commonly reported
radionuclides and their respective concentrations (EPA79, E 'A83, EPA89b, BEC80, GRE83,
GRE87, RAD88, RAD82, STY80, TEK79, UNS82, WAG82, ^ AG80). Secondly, radionuclide
distributions and concentrations were grouped in two cate ones, fly ash and bottom ash,
whenever reported. Thirdly, it was assumed that ash maten Is were comprised of 80 percent
fly ash and 20 percent bottom ash which includes be ler slags. Fourth, coal ash
concentrations for each radionuclide were weighted with ic distribution noted above to
account for the difference in specific activity between fly : ih and bottom ash. Fifth, the
B-4-18
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radioactivity in sludges was assumed to be essentially identical to that of ash. Finally, the
small amount (less than 5 percent) of fly ash which passes through particulate emission
systems and becomes airborne was ignored since such ash is not collected or disposed with
the other ash materials. For this report, the weighted (80 percent fly ash and 20 percent
bottom ash and slag) average radionudide concentrations are as follows:
Radionuclide Concentration (pCi/g)
Po-210 7.00
Pb-210 6.80
Ra-226 3.70
Th-228 3.20
Ra-228 1.80
Th-230 2.30
Th-232 2.10
U-234 3.30
U-238 3.30
U-235 0.16
4.4.2 Radon Flux Rates
Several important factors govern the exhalation rate of radon, including mineral form,
material density and porosity, particle size distribution, and moisture content. Changing
meteorological conditions, such as atmospheric pressure, surface wind velocity, and
differences between soil and air temperatures, are known to have pronounced effects on radon
emanation rates (NCR85, NCR87). The estimated radon-222 emanation rate is based on the
relationship of radium-226 concentration in the soil (pCi/g) to the area! exhalation rate
(pCi/m2-s). Given the varied properties of coal ash and factors governing radon emanation,
some simplifying assumptions were made in this assessment. Radon-220 (Rn-220) emissions
from the Th-232 decay chain are ignored in this report because the dose associated with this
noble gas is one or more orders of magnitude lower than that due to Rn-222 (UNS82).
The National Council for Radiation Protection notes that for typical soils, the average
radon emanation rate is about 0.5 pCi/m2-s per pCi/g (NCR85). The U.S. Nuclear Regulatory
Commission cites radon emanation rates for tailings and soils with varying moisture contents
based on work conducted by Tanner and Schiager (NRC80). The reported rates for wet,
B-4-19
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moist, and dry materials are 0.35, 0.65, and 1.2 pi/m2-s per pCi/g, respectively. Schiager
suggests a radon emanation rate of 1.6 pCi/m2-s for dry tailings (SCH74) based on the
assumption of an infinitely thick, dry tailings bed. Typically, about 90 percent of the source
term originates from the first 2 m of material.
Coal ash is generally believed to have a lower exhalation rate than soil since the ash
is vitrified (BEC80, WAG81). Radon is thought to be generated and to decay within the
particle in which Ra-226 is trapped. Beck reports that fly ash typically has a lower
exhalation rate th?" soil. For example, it is noted that the ratio of the emanation rate to the
production rate is about 15 percent for soil, but only about 2 percent for fly and bottom ash
(BEC89). Weathering may increase the exhalation rate. If ash particles are subjected to
weathering, it is conceivable that the radon exhalation rate would increase over time and
reach levels typical to those observed from natural soils (WAG81). Given that coal ash may
be disposed in settling ponds, water saturated areas, or be even capped with soil covers,
radon exhalation rates may in fact be lower than for soil.
Kalkwarf reports radon emanation coefficients ranging from 0.7 to 9.8 percent for
three sets of ash samples (15 measurements) and 1.8 percent for an ash sample from the
National Bureau of Standards (KAL85). The results reveal that smaller particles release
radon at a greater rate than larger ones. For example, the emanation coefficient for particles
less then 0.5 micrometers was about two times higher than that of particles in the range of
11 to 15 micrometers (um). If the 11 to 15 urn particle size range were used as the cutoff
point for characterizing radon emanation rates between large and small particles, the radon
emanation coefficient may be assumed to be about 3 percent for particles greater than 11 um
and 4.3 percent for particles less than 11 um. Ratioing these values to the soil radon
emanation coefficient rate of 15 percent and soil exhalation rate of 0.5 pCi/m2-s, a coal ash
exhalation rate of 0.13 pCi/m2-s per pCi/g is derived for the purpose of this analysis. This
exhalation rate is weighted to reflect the partitioning factor between fly ash (80 percent) and
bottom ash and boiler slag (20 percent). A radon emanation coefficient of 4 percent is used
in this report.
B-4-20
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4,4.3 Ex .ernyl Radiation Exposure Rates
N empirical information could be found which characterizes the radiation exposure
rates ass ciated with the disposal of coal ash. The EPA has conducted a study to estimate
potential loses and risks associated with environmental releases from coal and coal ash piles
at utility md industrial facilities with coal-fired boilers (EPA89a). The purpose of this study
was to p: )vide background information to consider exempting coal and coal ash piles from
theCER< LA importable quantity (RQ) notification requirements. Conservative models were
used to e timate potential radiation doses and resulting health risks to workers standing on
the piles md next to the piles (10 m away) and to a nearby resident assumed to reside 100
meters fi >m the piles. The exposure scenarios evaluated in the study were:
Direct radiation exposure
Airborne releases of radon and fugitive dusts
Pile leachate migration to groundwater
Pile surface water runoff to a nearby stream.
For direc radiation and airborne exposures, the potential doses and risks were analyzed for
both the >nsite workers and the nearby resident. Potential doses and risks from exposure
to contar inated groundwater and to surface water runoff were only analyzed for the nearby
resident.
Tl e dose and risk results from postulated exposures to the coal ash pile are
summari ed in Table B.4-6. The maximum lifetime risk of fatal cancer to a worker standing
on an as! pile for eight hours a day, five days per week, 50 weeks per year for 47 years was
estimate- to be 4.3 x 10*4; the maximum lifetime risk to a worker standing next to the ash
pile (10 i . away) for the same period was estimated to be 1.8 x 10"4. To put these risks in
perspecti e, a lifetime risk of 4.3 x 10*4 corresponds to an annual dose of 33 mrem and an
annual r sk of 9.2 x 10"6 for fatal cancers. This annual risk is an order of magnitude lower
than the bserved risk of job-related accidental death (1.1 x 10"4) for workers in all industries
in the U 5. in 1985. An annual exposure rate of 33 mrem/yr is at the low end of reported
exposure rates from natural background radiation in the U.S. For nearby residents, the
estimate! lifetime health risks, which are calculated to be in the range from 1.6 x 10"5 to
B-4-21
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Table B.4-6. Estimated doses and risks from exposures to a coal ash
pile (Source: EPA89a).
Yearly Dose Lifetime
Exposure Parameter (mrem) Riska
Worker
Direct radiation standing on pile 3.3 x 10+1 4.3 x 1CT4
Direct radiation standing near pile 1.4 x 10+1 1.8 x 1CT4
Particulate emissions 7.3 x 10"3 1.1 x 10*7
Radon emissions 5.2 x 10"3 4.3 x 10"6
Nearby Resident
Direct radiation 6.1 x 10'1 1.6 x 10'5
Particulate emissions 2.2 x 10'2 3.4 x 10*7
Radon emissions 2.8 x KT3 1.6 x 10'5
Groundwater 0.0 0.0
Surface water 7.3 x 10'1 4.6 x lO"6
(a) For workers, the lifetime risks are for fatal cancers based on exposures starting at
age 18 and ending at 65 years of age.
For the nearby resident, the lifetime risks are for fatal cancers based on a 70-year
life span.
B-4-22
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3.4 x 10'7, are well within the general range of health risks, 10"4 to 10'7, routinely considered
to be acceptable within the Super-fund program (EPA89a).
4.5 COAL ASH NORM SECTOR SUMMARY
4.5.1 Generic Coal Ash Disposal Site
The reference disposal site is assumed to be located in the Northeast because of the
higher population density and coal and ash utilization rates. The quantity of ash disposed
on site is representative of overall practices at utility coal-fired plants. The use of coal within
the industrial sector, to a certain extent, is also assumed to be implicitly addressed since the
quantity of coal consumption and ash generation in this analysis also reflects disposal
practices of industrial boilers. Accordingly, it is assumed that by evaluating utilities, the
results will also envelope, other things being equal, industrial facilities which are typically
much smaller in capacity or size.
The impoundment site is assumed to include all areas where ash is being handled as
part of the overall waste management activities, including disposal, grading, capping, etc.
During disposal activities, some utilities periodically cover exposed disposal cells with soil
caps to reduce wind erosion and minimize fugitive dust emissions. In this assessment, no
credit is taken for features or practices which tend to reduce such offsite releases.
The ash contained at the site is assumed to be disposed in a 25-hectare facility
totalling 1.3 million MT of ash materials. The ash impoundment is assumed to be square in
shape with dimensions of about 500 by 500 meters with a depth of nearly 5 meters, based on
an average ash density of 1.2 g/cc (EPR88, EPR87). The ash pile is not capped with a soil
cover. The effectively exposed area is about 250,000 m2. Depending upon the size of a power
plant and the ash content of the coal used, this volume may, in fact, represent more than one
year's worth of ash generation.
B-4-23
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4.5.2 Population Exposure
The population density near and around the site is estimated to be 780 persons per
square mile since the site is assumed to be located near a large urban population center.
This population density is based on the average population distribution of four Northeastern
States; namely, New Jersey, Connecticut, Rhode Island, and Massachusetts (BOC87).
4.5.3 Radionuclide Concentrations
Because of the disparate nature of the data regarding the presence and concentration
of radionuclides in ash materials, a simplified approach is used to estimate ash
concentrations for uranium and thorium and their decay products. Radionuclide distributions
and concentrations were grouped in two categories, fly ash and bottom ash. It was assumed
that ash materials were comprised of 80 percent fly ash and 20 percent bottom ash which
includes boiler slags. The coal ash concentrations for each radionuclide were weighted with
the distribution noted above to account for the difference in specific activity between fly ash
and bottom ash. For the purpose of this report, weighted (80 percent fly ash and 20 percent
bottom and slag) average radionuclide concentrations was derived for conducting the risk
assessment. The radionuclide concentrations used in the coal ash risk assessment of Chapter
D are given in Section 4.4.1.
B-4-24
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B.4 REFERENCES
ACA83 American Coal Ash Association, $2.1 Million Mine Subsidence Control Project
Initiated in Fairmont, Ash at Work, Newsletter, Vol. 15, 1983, No. 2.
ACA84a American Coal Ash Association, 40 Highway Departments Utilize Power Plant
Ash on Road Construction & Maintenance Projects, Ash at Work, Newsletter,
Vol. 16,1984, No. 1.
ACA84b American Coal Ash Association, Iowa Coal Land Being Reclaimed With Class
- C Ash, Ash at Work, Newsletter, Vol. 16, 1984, No. 5.
ACA84c American Coal Ash Association, NAA Message Board by Mr. Tobias Anthony,
Executive Vice President, Ash at Work, Newsletter, Vol. 16, 1984, No. 1.
ACA84d American Coal Ash Association, Northern States Power Has Remarkable Ash
Sales Record, Ash at Work, Newsletter, Vol. 16, 1984, No. 4.
ACA86a Coal Ash Book, American Coal Ash Association, 1986.
ACA86b American Coal Ash Association, Fly Ash Can Be Effective For Soil
Amendment, Ash at Work, Newsletter, Vol. 18, 1986, No. 2.
ACA87a American Coal Ash Association, Coal Combustion By-product - Production and
Consumption, Data sheets compiled by the ACAA, data set from 1966 to 1987.
ACASTb American Coal Ash Association, 1987 Coal Ash Symposium: The Road to
Improved Ash Utilization, Ash at Work, Newsletter, Vol. 19, 1987, No. 1.
ACA88 American Coal Ash Association 1988-1989 Business Plan, Washington, DC,
1988.
BEC80 Beck, H.L., et.al., Perturbations on the Natural Radiation Environment Due
to the Utilization of Coal as an Energy Source, Natural Radiation
Environment, CONF-780422, Vol. 2, pp. 1521-1558, 1980.
BEC89 Letter Transmittal - Paper titled: Some Radiological Aspects of Coal
Combustion, Harold L. Beck and Kevin M. Miller, Jan. 13, 1989.
BED70 Bedrosian, P.H., et al, "Radiological Survey Around Power Plants Using Fossil
Fuel", EERL 71-3, Eastern Environmental Radiation Laboratory, U.S.
Environmental Protection Agency, Washington, DC, 1970.
BOC87 Statistical Abstract of the United States, 108th Edition, U.S. Department of
Commerce, December 1987.
B-4-R-1
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BOR89 Telephone conversation with Mr. Erast Borissoff, Executive Director, American
Coal Ash Association, Washington DC, August 16, 1989.
BOY89 Telephone conversation with Mr. Dave Boyenga, JTM Industries, Atlanta,
Georgia, August 14, 1989.
CAI89 Telephone conversation with Mr. Gregg Cain, American Fly Ash Company, Des
Plaines, Illinois, August 14, 1989.
EEI88 Edison Electric Institute, Ashes and Scrubber Sludges-Fossil Fuel Combustion
By-Products: Origin, Properties, Use, and Disposal, Publication No. 48-88-05,
May 1988.
EEI89 Letter from Mr. John J. Novak, Edison Electric Institute, to Ms. Barbara
Hostage, USEPA/ERD, dated November 15,1989.
EIA88 Annual Outlook For U.S. Electric Power 1988 - Projections Through 2000, U.S.
DOE Energy Information Administration, DOE/EIA-0474(88), August 24,1988.
EIS87 Eisenbud, Menil, Environmental Radioactivity, Third Edition, Academic
Press, Inc., Orlando, FL, 1987.
EPA73 Environmental Protection Agency, Assessment of Potential Radiological Health
Effects from Radon in Natural Gas, EPA 520/1-73-004, November 1973.
EPA79 Environmental Protection Agency, Radiological Impact Caused by Emissions
of Radionuclides into the Air in the United States, Environmental Protection
Agency, EPA 520/7-79-006, Draft, August 1979.
EPA83 Environmental Protection Agency, Survey of Five Utility Boilers for
Radionuclide Emissions, Prepared by CGA Corporation under EPA Contract
68-02-3168, December 1983.
EPA84 Environmental Protection Agency, Radionuclides Background Information
Document for Final Rule, Volume II, EPA 520/1-84-022-2, Washington, D.C.,
October 1984.
EPA85 Environmental Protection Agency, Radiation Exposures and Health Risks
Associated with Alternative Methods of Land Disposal of Natural and
Accelerator-Produced Radioactive Materials (NARM) (DRAFT), Prepared by
PEI Associates, Inc., and Rogers & Associates Engineering Corp. under EPA
Contract 68-02-3878, October 1985.
EPA88 Environmental Protection Agency, Wastes from the Combustion of Coal by
Electric Utility Power Plants, Report to Congress, EPA/530-SW-88-002,
February 1988.
B-4-R-2
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EPA89a Environmental Protection Agency, Technical Background Supplement in
Support of Rulemaking Adjustment Activities for Reportable Quantities (RQ)
of Radionuclides, prepared by SC&A, Inc. under EPA Contract 68-02-4375,
March 1989.
X
EPA89b Environmental Protection Agency, Draft Environmental Impact Statement for
Proposed NESHAPS for Radionuclides - Background Information Document,
Vol. H, EPA/520-1-89-006, February 1989.
EPR87 Electric Power Research Institute, Classification of Fly Ash for Use in Cement
and Concrete, EPRI CS-5116, Final Report, April 1987.
EPR88 Electric Power Research Institute, High Volume Fly Ash Utilization Projects
in the United States and Canada, EPRI CS-4446, 2nd Edition, March 1988.
GRE83 Greiner, N.R., Williams, M.D., Wagner, P., Estimation of Radionuclide Releases
From Specific Large Coal-Fired Industrial and Utility Boilers, LA-9845-MS,
Los Alamos National Laboratory, August 1983.
GRE87 Greiner, N.R., Wagner, P., Natural Radioactivity in Lignites and Lignite Ash:
Final Report, LA-10942-MS, Los Alamos National Laboratory, April 1987.
KAL85 Kalkwarf, D.R., Emanation Coefficients for Rn in Sized Coal Fly Ash, Health
Physics Journal, Vol. 48, pp. 429-436, April 1985.
MEL89 Telephone conversation with Mr. Mike Miller, Electric Power Research
Institute, Coal Combustion System Division, Palo Alto, California, August 17,
1989.
NCR77 National Council on Radiation Protection and Measurement, Radiation
Exposure from Consumer Products and Miscellaneous Sources, NCRP Report
No. 56, 1977.
NCR85 National Council on Radiation Protection and Measurement, Evaluation of
Occupational and Environmental Exposures to Radon and Radon Daughters
in the United States, NCRP Report No. 78, May 1985.
NCR87 National Council on Radiation Protection and Measurement, Exposure of the
Population in the United States and Canada from Natural Background
Radiation, NCRP Report No. 94, December 1987.
NER87 Electricity Supply and Demand for 1987-1996, North American Electric
Reliability Council, November 1987.
NOV89a Telephone conversation with Mr. John Novak, Director, Water and Solid Waste
Activities, Edison Electric Institute, Washington D.C., January 25, 1989.
NOV89b Telephone conversation with Mr. John Novak, Edison Director, Water and
Solid Waste Activities Electric Institute, Washington D.C., August 15, 1989.
B-4-R-3
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NRC80 U.S. Nuclear Regulatory Commission, Final Generic Environmental Impact
Statement on Uranium Milling, NUREG-0706, Vol. Ill, September 1980.
RAD82 Radian Corporation, A Radiochemical Survey of U.S. Coals and Coal
Combustion By-Products, Prepared for the Electric Power Research Institute,
Research Project 1620, Final Report, Austin, Texas, September 1982.
RAD88 Radian Corporation, Assessment of NORM Concentrations in Coal Ash and
Exposure to Workers and Members of the Public, Prepared for the Edison
Electric Institute (USAWG), Austin, Texas, June 1988.
SCH74 Schiager, K.J., Analysis of Radiation Exposures on or Near Uranium Mill
Tailings Piles, U.S. Environmental Protection Agency, Radiation Data and
Reports, Vol. 15, No. 7, pp. 411-425, July 1974.
STY80 Styron, C.E., An Assessment of Natural Radionuclides in the Coal Fuel Cycle,
Natural Radiation Environment, CONF-780422, Vol. 2, pp. 1511-1520, 1980.
TEK79 Teknekron Research, Inc., Information Base (Including Sources and Emission
Rates) for the Evaluation and Control of Radioactive Materials to Ambient Air,
Task 2, Vol. 1, Prepared for the Office of Radiation Programs, U.S.
Environmental Protection Agency, July, 1979.
UNS82 United Nations Scientific Committee on the Effects of Atomic Radiation,
Sources and Effects of Ionizing Radiation, 1982 report to the General
Assembly, United Nations, New York, 1982.
WAG80 Wagner, P., and Greiner, N.R., Second Annual Report - Radioactive Emissions
from Coal Production and Utilization, October 1, 1979 - September 30, 1980,
Los Alamos National Laboratory, LA-8825-PR, July 1981.
WAG81 Wagner, P., and Greiner, N.R., Proceedings of the Workshop on Radioactivity
Associated with Coal Use, Held in Santa Fe, New Mexico, September 15-17,
1981, Los Alamos National Laboratory, LA-9106-C, December, 1981.
WAG82 Wagner, P., and Greiner, N.R., "Third Annual Report - Radioactive Emissions
from Coal Production and Utilization, October 1,1980 - September 30, 1981,"
Los Alamos National Laboratory, LA-9359-PR, June 1982.
B-4-R-4
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B.5 OIL AND GAS PRODUCTION SCALE
5.1 INTRODUCTION
Both uranium and thorium and their progeny are known to be present in varying
concentrations in underground geological formations from which oil and gas are produced
(BEL60, JOH73, PIE55). The presence of these naturally occurring radionuclides in
petroleum reservoirs has been recognized since the early 1930*3 and has been used as one of
the methods for finding hydrocarbons beneath the earth's surface (MAR87). Uranium and
thorium are highly insoluble and, as oil and gas are brought to the surface, remain mostly
in place in the underground reservoir. However, radium and the radium daughters are
slightly soluble, and under some conditions may become mobilized by the liquid phases in the
formation. When brought to the surface with liquid production streams, radium and its
daughters may remain dissolved at dilute levels, or they may precipitate because of chemical
changes and reduced pressure and temperature. Since radium concentrations in the original
formation are highly variable, the concentrations that precipitate out on the surfaces of oil
and gas production and processing equipment are also variable and may exhibit elevated
radioactivity levels. Scales and sludges that accumulate in surface equipment may vary from
background levels of NORM to elevated levels as high as tens of nanocuries per gram
depending on the radioactivity and chemistry of the geologic formation from which oil and
gas are produced and on the characteristics of the production process.
Since the radioactivity in oil and gas production and processing equipment is generally
low and of natural origin, its accumulation and significance were not noted and studied until
recently. The problem is now known to be widespread, occurring in oil and gas production
facilities throughout the world, and has become a subject of attention in the United States
and in other countries. In response to this concern, facilities in the U.S. and in Europe have
been characterizing the nature and extent of NORM in pipe scale, evaluating the potential
for exposures to workers, and developing methods for properly managing these low specific
activity wastes (EPF87, MCA88, MIL87, MIL88).
B-5-1
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In 1982, radium and thorium in measurable quantities were found in mineral scales
on British oil and gas production facilities in the North Sea. Because large quantities of
materials were being handled in the confined working area of offshore platforms, operators
developed special work procedures for protection against possible harmful effects of
radioactivity. After a review of the situation, the British government and oil industry
representatives issued guidelines governing worker safety, material handling, and waste
disposal (UK85).
In the U.S., the presence of naturally occurring radioactivity in mineral scale deposits
came to the attention of industry and government in the spring of 1986 when, during a
routine workover of a well in Mississippi, barium sulfate scale deposited in production tubing
was found to contain radium and thorium. Assays of this scale showed 6,000 pCi/g of
radium-226 and 1,000 pCi/g of thorium-232 coprecipitated in a barium sulfate matrix
(MAR87, MCA88). Because of the concern that some of the contaminated pipes, which had
been removed to nearby pipe cleaning facilities, may have contaminated the environment,
radiological surveys were conducted by the EPA's Eastern Environmental Radiation Facility.
These surveys showed some equipment with elevated external radiation levels and soil
contamination.
Both the oil and gas industry and state regulatory bodies, as well as the EPA, are
currently examining the problem of identifying and regulating NORM in oil and gas
production facilities and equipment. The American Petroleum Institute (API) has sponsored
studies to characterize accumulations of naturally occurring radioactivity in oil field
equipment and to determine safe methods for its disposal (API89, API90). The API has also
formed an Ad Hoc Committee on Low Specific Activity (LSA) Scale which has prepared a
draft measurement protocol for identifying producing areas where NORM scale exists
(API87). The Part N subcommittee of the National Conference of Radiation Control Program
Directors has been working since 1983 to develop model state regulations (PartN of
Suggested State Regulations for Control of Radiation) for the control of NORM (CPD87).
These model regulations are intended to help individual states develop their regulations in
a uniform way such that the regulations are consistent from state to state and with Federal
regulations. For example, the state of Texas has proposed NORM regulations that are very
similar to the Part N regulations, and Louisiana has regulations for NORM in scales and
sludges from oil and gas production. While the regulations are intended to apply generally
B-5-2
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to all NORM-containing materials, several parts would apply specifically to the oil and gas
industry pipe scale problem.
The American Petroleum Institute (API) has conducted an industry-wide survey of
radiation exposure levels associated with NORM in oil production and gas processing
equipment (API89). The purposes of the study were (1) to identify the geographic areas of
petroleum producing and gas processing facilities having the greatest occurrence of NORM,
and (2) to identify items of equipment at these facilities which have the highest NORM
activity levels. Over 36,000 individual observations were made in 20 states and two offshore
areas by participating petroleum companies using similar equipment and data collection
protocols. Radiation exposure levels were measured in units of urem/hr, and the results were
reported on survey data sheets provided to all participants. Background radiation levels were
also measured and reported for each site in order to differentiate the background effects from
contamination effects. The results of this study are summarized in section 5.4.3 of this
chapter.
Radium and radium daughters are also known to be present in elevated concentrations
in produced waters from oil production operations. In general, these produced waters are
reinjected into deep wells or are discharged into non-potable coastal waters. The impacts of
elevated concentrations of radionuclides in produced waters are not considered in this risk
assessment.
Volumes of NORM scales and sludges from offshore operations are also not included
in the inventories presented in this chapter nor in the impacts evaluation of Chapter D.
Radiation exposures to workers and to other individuals from offshore operations will be
similar to or less than exposures from onshore operations. However, total population impacts
might increase slightly if offshore operations were considered in this assessment.
This assessment is limited to NORM in oil and gas production equipment. NORM in
gas plant processing equipment is described but is not included in the risk assessment for
this sector category because the NORM is generally in the form of Pb-210 surface
contamination on the gas plant equipment. Consequently, it does not have a strong radon
or gamma emission component. Furthermore, the CPG and collective population effects from
B-5-3
-------
the production equipment are an upper bound to any health impacts from the gas plant
equipment.
In the following sections, descriptions are given of th6 oil and gas production industry,
and of the properties of oil and gas scale and sludge waste from production equipment. Also
provided are actual and projected amounts of scale and sludge produced by this NORM
sector, using the oil and gas production information. This information is used to assess
potential exposures and health impacts to members of the general public and critical
population groups. A radiological risk assessment is performed (see Chapter D) assuming
that both exposed populations reside near a generic site.
52 OVERVIEW OF OIL AND GAS PRODUCTION
U.S. crude oil production for the years 1970 through 1987 is shown in Table B.5-1.
The highest oil production rate occurred in 1970 at almost 9.64 million barrels per day.
Crude oil production has since declined to only about 8.35 million barrels per day in 1987.
The production of crude oil in the U.S. is closely tied to the price of crude oil which is
determined on a world-wide scale by OPEC countries, and to world demand for crude oil.
Thus U.S. oil production is subject to fluctuations that depend on world-wide political and
economic conditions as well as on U.S. needs for crude oil.
U.S. production of natural gas for the years 1970 through 1987 is shown in Table
B.5-2. Production of natural gas peaked in 1973, and has been declining since that year. In
1987, marketed production of natural gas was about 76 percent of the volume generated in
1973. This decline in marketed production is due both to the more efficient use of natural
gas for home heating and to the modernization and improvements in efficiency of industrial
furnaces.
Oil and gas production occurs throughout the U.S. and in offshore coastal areas. Table
B.5-3 lists the number of operating crude oil production wells in each state and the amount
of crude oil obtained from these wells in 1987 (PET88). Table B.5-4 lists the number of
B-5-4
-------
Table B.5-1. U.S. crude oil production. (Source: PET88)
Year
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
Million bbls/dav"
9.637
9.463
9.441
9.208
8.774
8.375
8.132
8.245
8.707
8.552
8.597
8.572
8.649
8.688
8.879
8.971
8.680
8.349
a A barrel of oil has a capacity of 42 gallons.
B-5-5
-------
Table B.5-2. U.S. natural gas production. (Source: PET88)
Year
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
Billion Cubic Feet
21,921
22,493
22,532
22,648
21,601
20,109
19,952
20,025
19,974
20,471
20,180
19,956
18,520
16,822
18,230
17,198
16,791
17,150
B-5-6
-------
Table B.5-3. Crude oil production for 1987 by state. (Source: PET88)
State-Wide Rank
State
United States11
Alabama
Alaska
Arizona
Arkansas
California
Colorado
Florida
Illinois
Indiana
Kansas
Kentucky
Louisiana
Michigan
Mississippi
Missouri
Montana
Nebraska
Nevada
New Mexico
New York
North Dakota
Ohio
Oklahoma
Pennsylvania
Number of
Producing
Wells
620,181
875
1,216
23
8,398
45,694
5,642
122
32,307
7,449
48,051
22,974
29,758
4,996
2,143
200
4,050
1,852
35
18,401
4,428
3,474
30,013
101,745
14,271
Tfif^iaand
Barrels
3,629,553
26,447
717,415
131
14,960
400,808
33,182
9,365
23,980
3,738
67,914
6,838
538,468
30,352
28,833
110
25,789
6,091
3,112
86,928
710
44,271
12,153
168,688
3,302
Number of
Producing
Wells
24
23
31
13
4
15
28
5
14
3
8
7
16
20
26
18
21
29
9
17
19
6
2
11
Total
Production
14
2
29
17
4
11
19
16
23
8
20
3
12
13
30
15
21
25
7
27
9
18
5
24
B-5-7
-------
Table B.5-3. (continued)
State
South Dakota
Tennessee
Texas
Utah
Virginia
West Virginia
Wyoming
Number of
Producing
Wells
149
648
198,163
1,785
29
15,850
10,953
Thousand
Barrels
1,644
614
898,237
40,168
17
5,390
134,612
State-Wide
t
Number of
Producing
Wells
27
25
1
22
30
10
12
Rank
Total
Production
26
28
1
10
31
22
6
a Includes 4,487 wells and 295,286 thousand barrels at unspecified locations.
B-5-8
-------
Table B.5-4. Natural gas production for 1987 by state. (Source: PET88)
State-Wide Rank
State
United States'1
Alflbama
Alaska
Arkansas
California
Colorado
Florida
Illinois
Indiana
Kansas
Kentucky
Louisiana
Michigan
Mississippi
Montana
Nebraska
New Mexico
New York
North Dakota
Ohio
Oklahoma
Pennsylvania
South Dakota
Tennessee
Texas
Number of
Producing
Wells
253,856
1,000
87
2,847
1,293
3,948
0
238
808
11,280
10,493
16,647
670
749
2,100
b
23,413
5,180
103
33,369
26,595
26,000
52
790
45,552
Billion
Cubic Feet
17,155,162
117,227
1,966
131,821
427,935
162,506
8,430
2,975
500
394,906
88,500
5,096,369
161,629
137,890
46,330
1,900
818,453
36,200
62,857
191,990
1,987,261
171,500
2,900
4,500
6,060,960
Number of
Producing
Wells
16
25
12
15
11
27
23
17
8
9
7
21
19
14
___b
6
10
24
3
4
5
26
18
1
Total
Production
14
26
13
6
10
22
24
28
7
17
2
11
12
19
27
4
20
18
8
3
9
25
23
1
B-5-9
-------
Table B.5-4. (continued)
State-Wide Rank
State
Utah
Virginia
West Virginia
Wyoming
Number of
Producing
Wells
497
685
33,950
2,104
Billion
Cubic Feet
93,106
23,225
115,856
440,583
t
Number of
Producing
Wells
22
20
2
13
Total
Production
16
21
15
5
a Includes 3,306 wells and 364,887 billion cubic feet at unspecified locations.
b Not specified.
B-5-10
-------
operating natural gas wells in each state and the marketed production of natural gas from
these wells in 1987.
Almost one-third of the operating crude oil production wells in the U.S. are located in
the state of Texas which also ranked first in crude oil production in 1987. Five states (Texas,
Oklahoma, Kansas, California, and Louisiana) account for two-thirds of the total number of
operating crude oil production wells and also produced almost 60 percent of the crude oil in
1987. Alaska, which ranks 24th in the number of producing wells, ranked second in crude
oil production in 1987, producing 24 percent of the total barrels of crude oil. There are
extensive oil producing areas in the humid coastal regions of Texas, Louisiana, and
California, the north slope of Alaska, and some arid regions of northern Texas, Oklahoma,
and Kansas. The states of Illinois, Indiana, Ohio, Pennsylvania, and West Virginia rank high
in the number of producing wells, with 16 percent of the wells, but low in total production,
with only about one percent of production. The wells in these states are mostly stripper wells
for the removal of small amounts after the easily recoverable oil has been taken from the
reservoirs. Stripper wells do not necessarily result in less of a NORM problem than other
producing wells, and may, in fact, result in a greater problem. Stripper wells will produce
more water and, therefore, may bring more radium to the surface.
The state of Texas ranks first in the number of producing natural gas wells and also
ranked first in marketed production of natural gas in 1987, with 35 percent of the total
marketed production. Three states - Texas, Louisiana, and Oklahoma - have 35 percent of
the producing natural gas wells, and produced more *h«« three-fourths of the natural gas
marketed in the U.S. in 1987.
5.3 OIL AND GAS srAT.R AND SLUDGE WASTE PRODUCTION
5.3.1 Origin and Nature of NORM in Oil and Gas Scale and Sludge
The initial production of oil and gas from a reservoir is usually dry. However, as the
natural pressure within the petroleum bearing formation falls, groundwater present in the
B-5-11
-------
reservoir will also be produced with the oil and gas. This formation water contains dissolved
mineral salts, a very small proportion of which may be radioactive because of the presence
of uranium and thorium and their decay products in the underground formation. Thus, the
amount of NORM material from a producing field generally increases with the increases in
the amount of water pumped from the formation. The uranium and thorium are relatively
insoluble and remain mostly in place. However, radium (Ra-226 and Ra-228 from the
uranium and thorium decay chains) is much more soluble and, under some conditions,
becomes mobilized by the liquid phases in the reservoir.
The natural formation water will undergo changes in temperature and pressure as it
is brought to the surface with the oil and gas and may, under certain conditions, deposit scale
and sludge within the oil production system. This scale consists principally of barium,
calcium, and strontium compounds (sulfates, silicates, and carbonates). Because the
chemistry of radium is similar to that of barium, calcium, and strontium (all are Group IIA
elements), radium may also precipitate to form complex sulfates or carbonates.
Deposits in production equipment are generally in the form of thick and hard scale,
loose material, or oily sludge. The scale in these chemical matrices is very hard and
relatively insoluble. It may vary in thickness from a few millimeters to more than an inch.
Scale deposits in production equipment may at times become very thick, and some
accumulations have been known to completely block the flow in pipes as large as 4 inches in
diameter. Sludge often contains silica compounds, but may also hold significant amounts of
barium. Dried sludge which is low in oil content is similar to soil in appearance and
consistency, while some sludge remains very oily.
A basic flow diagram for oil and gas production is shown in Figure B.5-1. The oil and
gas production stream is processed in a separator where the oil, gas and water are divided
into separate streams based on their different fluid densities. Most of the solids in the
original fluid stream are removed in the separator and accumulate there. The production
stream may be further treated using a heater/treater to separate oil from water and sludge.
Most of the NORM precipitates or settles out of the production stream and remains in the
piping, separators, heater/treaters, and other production equipment. The produced water
flows from the separators into storage tanks from which it is injected down disposal wells or
recovery wells.
B-5-12
-------
V
t-«
CO
DRY GAS
V) METER
OIL AND GAS
PRODUCTION
WELL
GAS
DEHYDRATOR
OIL AND GAS
SEPARATOR
1
PRODUCED
WATER
STORAGE
TANK
WATER
SEDIMENT
EMERGENCY PIT
OIL
STORAGE
TANK
METER
TO OIL
PIPELINE,
BARGE,
OR TRUCK
SEDIMENT
ENHANCED
RECOVERY OR
DISPOSAL
INJECTION
WELL
RAE-103341
RESERVOIR
Figure 0.5-1. Typical production operation, showing separation of oil, gas, and water.
-------
The NORM accumulated in production equipment scales typically contains radium
copreripitated in barium sulfate (BaSO4). Sludges are dominated by silicates or carbonates,
but also incorporate trace radium by copredpitation. Ra-226 is generally present in scales
and sludges in higher concentrations than Ra-228. The nominal activity ratio appears to be
about three times as much Ra-226 as Ra-228. Typically, Ra-226 is in equilibrium with its
decay products, but Ra-228 is not in equilibrium with its decay products. Reduced
concentrations of Ra-228 daughters are due to the occurrence in the thorium series decay
chain of two radium nuclides (Ra-228 and Ra-224) separated by Th-228 with a 1.9-year
half-life. Thus radium mobilized from the formation initially becomes depleted in Ra-224
(half-life = 3.6 days) until more is generated by Ra-228 decay through Th-228.
For the sake of simplicity, the term radium is used in this section to refer to the
combination of Ra-226 and Ra-228. Long-term radiological concern in waste disposal is
dominated by the daughter products of Ra-226 rather than Ra-228 due to the much longer
half-life of Ra-226 (1,600 years versus 5.75 years for Ra-228). Both are usually considered
together in waste disposal decisions, however, since they are not distinguished by simple field
measurements.
NORM radionuclides may also accumulate in gas plant equipment from Rn-222
(radon) gas decay, even though the gas is removed from its Ra-226 parent. The more mobile
radon gas mostly originates in underground formations and becomes dissolved in the organic
petroleum fractions in the gas plant Once in surface equipment, it is partitioned mainly into
the propane and ethane fractions by its solubility. Gas-plant deposits differ from oil
production scales and sludges, typically consisting of an invisible plate-out of radon daughters
on the interior surfaces of pipes, valves, and other gas plant equipment. These deposits
accumulate from radon daughters at natural levels from the very large volumes of gas
passing through the system. Since radon decays with a 3.8-day half-life, the only
radionuclide remaining in gas plant equipment that affects its disposal is Pb-210, which has
a 22-year half-life. Lead-210 decays by beta emission, with only low-intensity, low-energy
gamma rays.
B-5-14
-------
5.3.2 Oil and Gas Scale and Sludge Production Rates
The volume of NORM scale and sludge that is produced annually is uncertain, but
recent estimates suggest that as many as one-third of domestic oil and gas wells may produce
some radium-contaminated scale. It appears that the geological location of the oil reserve
and the type of production operation strongly influences the prevalence of NORM
accumulations. A review of surveys conducted in 13 states revealed that the number of
facilities reporting NORM in production wells ranged from 90 percent in Mississippi to none
or only a few in Colorado, South Dakota, and Wyoming (MCA88). However, 20 to 100 percent
of the facilities in every state identified NORM in heater/treaters. A separate estimate based
on Mississippi data indicates that one-half of the wells do produce NORM scale and ten
percent of these have scale with elevated radium concentrations (BLI88).
An analysis performed in the U.K. estimated that a typical well of 10,000 feet with
a 5.5-inch diameter pipe will produce 2 tons of scale per year for a well supplying 3,000
barrels of oil per day. In the U.K. oil producing area, there are approximately 850 production
wells (compared to nearly 2 million wells in the U.S.). Based on this data, the U.K.
estimated that their petroleum production wells would generate one thousand tons of scale
per year (SCA88). Applying the relationship for the U.K. wells of 2 tons of scale per 3,000
barrels of oil to the U.S., which produces about 8.3 million barrels of oil per day (EIA88), the
volume of scale produced in the U.S. is estimated to be about 6,000 MT per year.
For this report, a reference oil and gas production facility consisting often production
wells is assumed, and the NORM waste associated with this facility is estimated from data
developed by the American Petroleum Institute (API) and based on the results of laboratory
and field work. The API has developed a database for oil and gas production wells
throughout the U.S. and for equipment present at representative facilities. This database
includes information on the estimated quantities of scale and sludge in production equipment
derived from radiation measurements at facilities throughout the U.S. (API89).
Estimated quantities of scale and sludge for the representative 10-well production
facility, based on observations and field measurements at several facilities, are shown in
Table B.5-5. In defining the equipment, the API industry-wide survey headings were used.
The typical facility is assumed to consist of ten production wells with an average life of 30
B-5-15
-------
Table B.6-6. Equipment listing and characteristics of a 10-well production facility.**
Total
o>
Equipment Description
Production Facilities
Field Piping
Oil Line Piping
Valves
Manifold
Hesden/Manifolds
Piping
Meter
Meten. Screens. Filters
Pump
Oil Lease Pumps
Teat/Production Separators
Free Water Knockouts (FWKO)
Gun Band (Wash Tanks)
Sunk
Oil Stock Tanks
VRU (Vapor Recovery Unit)
Suction Scrubbers
WINJ
Injection Wells
Injection Pumps
Well and Well Head
Production Wells (Tubing)
Christmas Trees
H/T
Healer Troalcra
Sump
Pig Traps
PiU
Unit
ft.
ea.
M.
ft.
ea.
ea.
ea.
ea.
ea.
ea.
ea.
ft.
ea.
ft.
ea.
ea.
ea.
ea.
Total
No. of
Unite
46.000
26
6
300
6
2
2
1
1
2
1
6.000
1
13.800
1
1
3
3
Gross Dimensions
rio6'Dis.(4'NOM.)
1- to 6' Dia.
3" Dia. 151
3" Dia.
2* Dia. > 2'
6hp(2'*2'>2>)
3' Dia. * IV
4' Dia. * Iff
(400 bbl.) 12* Dia. 1 20*
(600 bbl.) 16* Dia. « 20*
10" Dia. > 4*
3' Tubing
(150hp)6>i6*i6>l
2- Dia.
0
4' i 26'
10- Dia. > 3'
(65 Gal) 22' Dia. x 3'
Wall
Thickness
(Inches)
0.36
1.00
0.30
0.30
060
1.00
1.00
0.60
0.26
0.26
100
0.26
1.00
0.26
100
0.26
0.60
008
NOBM NORM
Seals Sludge
Thickness Thickness
(Inches) (Inches)
0.08
0.30
0.10
0.08
0.10
0.10
0.10 4.00
0.10 2.00
0.10 8.00
0.10 16.00
0.10
0.10
0.10
007
002
0 25 12.00
0.10
0 10 12.00
Disposal
Volume
As Is
(en. ft.)
16,395
B
5
16
1
16
141
ISO
2.260
7.070
314
1.000
125
1.204
460
314
6
30
Scale Sludge
Volume Volume
(cu.lt) (eu.n.)
1.227.74
2.60
0.60
1.2
0.20
1.81 4.71
1.26 2.09
8.17 0.62
21.67 441.79
2.33
131.00
126
161.38
2.00
7.08 12.67
026
0.68 7.92
Equipment
Volume
(cu.fl.)
5.652.00
8.33
1.78
6.00
2.00
18.08
7.50
20.42
64.17
23.33
327.50
12.60
602.17
100.00
7.08
1.25
0.47
-------
Table B.5-5. (continued)
Equipment Deacrlptlon
WL1NE
Water Lines
Valves
WTANK
Water Storage Tank*
Total
No. of
Unit Unlta
Groaa Dlmenalona
NORM
Wall Scale
Thlckneaa TblekneM
(Inchea)
-------
years. It is further assumed that tubing and some of the pipe in the wells will be replaced
about every seven years giving a total of 3 replacements of the original tubing during the
30-year facility life. Sludge is assumed to be emptied from tanks and heater/treaters about
every three years. Thus the quantities of NORM waste shown in Table B.5-5 only reflect
short-term (i.e., less than 10 years) accumulations.
A review of Table B.5-5 indicates that the majority of the waste volume originates
from the disposal of piping and valves, stock tanks, water storage tanks, wash tanks, and
water lines and piping. Based on these values and the additional quantities of sludge
generated during periodic cleaning of tanks, it is estimated that over 250 m3 (9,000 ft3) of
scale and sludge are produced during a 30-year life cycle of the characteristic oil and gas
production facility. It should be noted that it is difficult to translate the disposal volume into
a weight because the waste volume is comprised of equipment characterized with large
internal void spaces. In addition, the scale or sludge is trapped or internally coated in the
equipment. Relatively speaking, the scale or sludge in such components usually makes up
a small fraction of the total weight.
5.3.3 Oil and Gas Scale Handling and Disposal
In the past, when scale in oil and gas piping became a problem, the pipes were sent
off-site to companies that would either clean out the scale or recycle the pipes. Pipes are
cleaned by a process called rattling in which the scale is reamed out using a bit on a long
shaft which is rotated inside the pipe. As the scale was not known to be radioactive it was
stored on the ground at pipe cleaning yards or washed into the nearest pond or drainage
basin (BAI88). Sludge from tanks was placed in pits or lagoons. Some piping containing
scale was given to schools for use in playground equipment and as material for vocational
welding classes (FUE88).
Because of concern that some of the contaminated pipes which were removed to nearby
pipe cleaning facilities may have contaminated the environment, EPA's Eastern
Environmental Radiation Facility conducted environmental radiological surveys. Their
results showed some equipment and locations with external radiation levels above 2 mR/hr
and soil contamination above 1,000 pCi/g of radium-226. Some contamination had been
B-5-18
-------
washed into a nearby pond and drainage ditch at one site, as well as into an agricultural field
with subsequent uptake of radium by vegetation (POR87).
Now that most companies in the petroleum industry are aware that pipe scale may
be radioactive, pipes are usually measured for radioactivity. Piping and equipment
containing NORM is generally being retained in controlled storage pending the promulgation
of disposal regulations (CRC88, TDH89, DEQ89). Scale and sludge that is removed from
piping and equipment is placed in drums and stored for later disposal.
Improper disposal of radioactive scale might lead to ground and surface water
contamination, even though the scale is very insoluble. In addition, direct exposures can
occur to individuals working or residing near the disposal site. Homes built over areas where
scale has been disposed could have higher indoor radiation exposure levels and radon
concentrations. There is probably little likelihood that radioactive scale would be used in
building materials because of its physical properties. Since the yearly generation rates
involve minimal volume of wastes, it is also unlikely that a commercial outlet would accept
scale for incorporation in building materials.
The American Petroleum Institute (API) has recently sponsored a study to
characterize accumulations of naturally-occurring radioactivity in oil field equipment, and to
determine safe methods for their disposal. An analysis of disposal alternatives has been
prepared (API90) which employs computer models to evaluate the risks from radiation
exposures via seven different environmental pathways including radon inhalation, external
gamma exposure, groundwater ingestion, surface water ingestion, dust inhalation, food
ingestion, and skin beta exposure from NORM particles. Twelve waste disposal alternatives,
ranging from landspreading to disposal in underground formations were evaluated. The
disposal alternatives were evaluated in both humid and arid permeable geohydrological
settings due to their differences in environmental transport of radioactivity. Analyses of a
humid impermeable site were intermediate. Maximum NORM concentrations were computed
corresponding to the greatest concentrations of NORM nuclides that could utilize a given
disposal alternative without exceeding defined radiation exposure limits via a given exposure
pathway.
B-5-19
-------
5.3.4 Twenty-Year Oil and Gas Scale and Sludge Volume Est mates
For this assessment, the 20-year volume of NORM scale and; ludge from oil and gas
production equipment is estimated based on the number of crude oil jroduting wells shown
in Table B.5-3 and the waste volume data characterizing a represents ive 10-well production
facility shown in Table B.5-5. As described in Section 5.3.2, the -epresentative facility
consists of 10 production wells with an average life of 30 years. Piping and tubing is replaced
about every seven years. Sludge is emptied from tanks and heater/tre .ters about every three
years. Assuming that the NORM waste volumes shown in Table B. -5 are volumes at the
time piping is replaced or sludge is removed, the volume of NORM aste generated at the
10-well facility over a 20-year period is estimated to be about 250 m (9,000 ft3).
The total 20-year volume of NORM scale and sludge from all atilities in the U.S. is
estimated on the assumption that the number of producing wells shown in Table B.5-3
(approximately 620,000 wells) will not change significantly during the lext 20 years. Because
U.S. oil production is based not only on U.S. demand but also on w -rid-wide political and
economic conditions, this assumption is subject to large uncertain ies. The API-NORM
database used to derive the waste volume information in Table B.£ 5 was also applied to
estimate the amount of equipment contaminated with scale and si dge from different oil
producing regions. This was done by fitting the data to a log-normal distribution using the
maximum and minimum measurements and the total number of measurements. It is
estimated that about 30 percent of the producing wells in the U 3. contain equipment
contaminated with NORM scale and sludge. The total volume of c ntaminated scale and
sludge generated over a 20-year period is estimated to be about 4.6 ir Uion m3. The mass of
this material is estimated to be 8.3 million MT, using a waste densi / of 1.8 MT/m3.
B-5-20
-------
5.4 RADIOLOGICAL PROPERTIES OF OIL AND GAS SCALE AND SLUDGE
5-4.1 Radionuclide Concentrations
Naturally-occurring radioactive material (NORM) is present in the earth in varying
concentrations in the geological formations from which oil and gas are extracted. Elevated
NORM concentrations in oil and gas production equipment result when Ra-226 and Ra-228
and their decay products co-precipitate with mineral scales, such as BaSO4, that form
deposits on the insides of field production equipment. Concentrations of NORM radionuclides
in scale and sludge of petroleum production equipment can vary from essentially background
(about 1 pCi/g) to tens of thousands of picocuries per gram. Factors which can affect the
magnitudes of NORM concentrations in oil and gas production equipment include the location
of the production facility, the type of equipment, how long the production well has been in
operation, and changes in temperature and pressure that take place during extraction of the
petroleum from the underground formation.
As discussed in Section 5.4.3, an American Petroleum Institute (API) industry-wide
survey of radiation exposure levels of NORM in oil and gas production equipment (API89)
showed a wide variation in NORM activity levels depending on the geographic origin of the
equipment. The geographic areas with the highest equipment readings were northern Texas
and the gulf coast crescent from southern Louisiana and Mississippi to the Florida
panhandle. Very low levels of NORM activity were measured in equipment from California,
Utah, Wyoming, Colorado, and northern Kansas.
The highest concentrations of radium appear to occur in the wellhead piping and in
production piping near the wellhead. The concentration of radium deposited in separators
is about a factor of ten less than that found in wellhead systems. There is a further
reduction of up to an order of magnitude in radium concentration in heater/treaters and in
sludge holding tanks. Concentrations of radium in scale deposited in production tubing near
wellheads can range up to tens of thousands of picocuries per gram. The concentrations in
more granular deposits, found in separators, range from one to about one thousand picocuries
per gram. Higher concentrations are associated with hard scale deposits, apparently
B-5-21
-------
associated with precipitation from the water phase. NORM concentrations in sludge deposits
in heater/treaters and tanks are generally around 50 pCi/g.
The quantity and concentration of NORM waste in oil and gas production equipment
also changes with time as the relative quantities of gas, oil, and water in the producing
geological formation change. The trend is for the relative quantity of NORM to increase as
the well ages and as gas and oil resources are depleted.
In addition to the previously cited API study (API89) which provides data on radiation
exposure levels from NORM in petroleum production equipment, several other studies, both
in the U.S. and in other countries, have been made to evaluate NORM concentrations in oil
and gas scale. A British study of Ra-226 concentrations in oil and gas scale in production
facilities in the United Kingdom revealed concentrations in scale ranging from 10 to over
100,000 pCi/g (MCA88). The highest radium concentrations were reported in downhole
tubing and valves and ranged from 1,000 to 410,000 pCi/g. The measurements targeted scale
with suspected elevated Ra-226 activities. Accordingly, these results probably represent a
biased estimate of the Ra-226 concentration in scale.
One survey of U.S. facilities included the analysis (for Ra-226) of 125 scale samples
collected from areas of elevated external gamma readings. The Ra-226 concentration in these
samples ranged from 50 pCi/g to as high as 30,000 pCi/g, with an average of 5,484 pCi/g
(MIL88). Since the study was done on scale with suspected high levels of radium, these
concentrations probably also represent a biased estimate.
A survey of 25 facilities, performed by the E&P Forum, revealed Ra-226 concentrations
ranging from less than 27 pCi/g to over 27,000 pCi/g (EPF87). Exxon Corporation has
speculated that levels of 800 to 900 pCi/g may be common in the U.S., with some regional
trending. Chevron speculates that levels of 20 to 25 pCi/g may be more common; however,
taTilc bottoms may have concentrations as high as 100 pCi/g, and heater/treater units and
separators may be characterized by scale with concentrations as high as 600 pCi/g (BLI88).
A more realistic estimate of the average Ra-226 concentration in oil and gas scale and
sludge may be derived from 6,274 external gamma readings taken throughout several U.S.
production facilities (SCA88). Based on these readings, and using a conversion factor of 1 to
B-5-22
-------
5 pCi/g per uR/hr above background (MIL87), the following distribution of Ra-226
concentrations in production equipment were estimated:
Median: 6 pCi/g
Average: 125 pCi/g
90 percentile: 250 pCi/g
99 percentile: 2,615 pCi/g
Maximum: 37,500 pCi/g
In view of the wide distribution of the reported data, it is difficult to define a generic
set of radionuclide concentrations. It is also believed that the reported data favor equipment
with elevated concentrations, while those that are low are often ignored or not reported. For
the purpose of this report, the nominal concentration of radium in oil and gas scale is
estimated using an approach with the following assumptions:
The amount of scale and sludge in equipment of the generic facility is as
shown in Table B.5-5.
Average radiation exposure rates for specific types of equipment are taken
from the API data base.
Conversion of external gamma exposure rates to radium concentrations in
different types of equipment are based on a conversion of 1 to 5 pCi/g per
uR/hr above background.
Since the instrument response for Ra-226 and Ra-228 and their decay products is
similar, the estimated concentration is based on total radium. The weighted radium
concentration, in scale and sludge from oil and gas production equipment, is estimated to be
210 pCi/g. The Ra-226 and Ra-228 concentrations are 155 pCi/g and 55 pCi/g, respectively.
The weighting factor includes the presence of different amounts of scale and sludge in
equipment (see Table B.5-5) and the relative measurements on the different types of
equipment. It is assumed that the decay products of radium are in equilibrium. In
summary, the radionuclides and their respective concentrations used in this assessment are
as follows:
B-5-23
-------
Radionuclide Concentration (pCi/g)
Po-210 155
Pb-210 155
Ra-226 155
Th-228 55
Ra-228 55
Th-230
Th-232
U-234
U-235
U-238
5.4.2 Radon Flux Rates
No readily available information was found characterizing radon emanation rates from
oil and gas scale waste. As was discussed earlier, it is difficult to characterize radon
emanation or flux and disposal or storage methods. For example, particle grain size and the
thickness of the scale deposits may govern the radon emanation rates. Similarly, the
presence of oil or other petroleum products associated with the scale or sludge may reduce
radon flux rates. Finally, since much of this waste is held within equipment (internally
deposited), it may be difficult or even impractical to characterize radon emanation rates from
internal surfaces. As was noted earlier, the presence and concentration of Ra-226 will govern
radon emanation and diffusion properties from scale and sludge. For the purpose of this
report, it is assumed that a radon emanation coefficient 0.1 would best characterize oil and
gas scale and sludge waste (RAE88). This is somewhat lower than background radon
emanation coefficients which are known to vary from about 0.2 to 0.4 in soils (NCR87).
5.4.3 External Radiation Exposures Rates
The results of a statistical evaluation of the exposure level data from the API
industry-wide survey (API89) are shown in Table B.5-6. The table shows the results on a
national basis in terms of difference over background by facility and type of equipment. The
abbreviations used to specify equipment type are shown in Table B.5-7.
B-5-24
-------
TaDM &A-O. aiaiuncai anatyau 01 raaiaaon expamrv IOVBIB 1111 mmn win nvnro u> «» |>rwu««.»««u
and gaa proceeding equipment - national eammary. (Soaree: API89)
DlfTerence Above Background (urem/hr)
Eouloment
~~ - -* Hit
Fadlitiee
WOTHER
WPROD
METER
PUMP
OTHER
STANK
MANIFOLD
SUMP
SEP
H/T
WTANK
VRU
WINJ
WUNE
FUNE
Gam Producing
Facilities
COMPRESSOR
DEHYDRATOR
SWEETENER
INLET SCRUB
METER
CRYO UNIT
OTANK
OTHER
FRAC TOWER
REFRIGER
BOTTOMS PUMP
PTANK
OPUMP
PPUMP
Number of
Otaeivatlona
24
2324
306
1393
2397
7006
2537
454
7887
2962
3431
116
102
341
1748
648
244
234
693
101
60
423
430
272
143
40
124
232
71
Number of
Above
Background
5
777
72
424
1007
26B6
895
253
3816
1495
2140
25
50
176
419
119
72
30
156
32
20
140
165
123
66
30
90
114
63
Minimum
1.2
0.1
1.0
0.1
0.1
0.1
0.1
0.1
0.1
0.1
0.1
OJ
1.0
OJ
0.1
OJ
OJ
OJ
0.1
OJ
1.0
OJ
OJ
OJ
0.1
0.6
0.5
0.4
0.1
25th
Pereentile
1.8
1.0
1.0
1.0
1.0
2.0
1.0
3.0
2X1
2.0
3X1
2.0
4.0
8.0
7.0
1.0
US
1.0
1.0
1.15
2X1
2.0
2X1
1J5
2.0
3.0
7J
6.8
9.5
Median
2X1
2J
3.0
3.0
4.0
4.0
6.0
7.0
7.8
8.0
8.0
17.0
20.0
34.6
42.0
2.0
3.0
3.46
5.0
5.5
6.0
6.0
7.0
9.6
16.0
17.0
25.0
27.76
31.0
76th
Pereentile
3.75
7.9
6.76
14.0
15.0
14.0
65.0
26.5
40.0
47.0
35.0
207.5
56.25
100.0
112.0
3.0
6.65
19.5
19.0
51.0
21.9
30.0
23.0
33J
68.75
45.25
65.75
98.26
97 JS
Maximum
5.5
1487.0
92.0
986.0
3786.0
2476.0
2996.0
793.0
4491.0
3490.0
3786.0
1287.0
886.0
2790.0
2991.0
490.0
529.0
220.5
701.0
695.0
2985.0
383.0
995.0
395.0
596.0
220.0
680.0
1391.0
1041.0
B-5-25
-------
Table &S4. (continued)
Difference Above Background (prem/hr)
Number of
Obeervationa
Nambcrof Above 26th 75th
Equipment Obeervationa Background Minimum PereenHle Median Pereentlle Ma»lmnm
PBOOLJNE 146 82 0.1 13.75 36.0 11O5 1080.0
PUMP 3 2 34) 3.0 38.0 73.0 73.0
REFLUX PUMP 110 96 OJ ISA 76.0 291.0 2986.0
I 6.0 7.0 9.0
B-5-26
-------
Table B.5-7. Abbreviations used to designate equipment types in oil
production and gas processing facilities.
Abbreviation
Description
Oil Production
Equipment
FUNE
H/T
MANIFOLD
OTHER
PUMP
SEP
STANK
SUMP
VRU
WINJ
WOTHER
WPROD
WLINE
WTANK
Flow lines to include all valves and elbows
Heater treater
Manifold/header piping, valves, chokes, etc.
All other measurements on service equipment
All pumps
Separators of all types
Stock tanks
Sumps to include pits, pigtraps, ponds, etc.
Vapor recovery units
Injection wellhead
Other wellheads except injection and production wellheads
Production wellhead
Water lines to include all valves and elbows
Water tanks
Gas Processing
Equipment
BOTTOMS PUMP
COMPRESSOR
CRYO UNIT
DEHYDRATOR
FRAG TOWER
INLET SCRUB
METER
OPUMP
OTANK
Pumps transferring liquids from the bottoms of towers
Compressors and associated equipment
All cryogenic process equipment
Dehydration equipment to include Glycol, EG, TEC
systems, etc.
All process towers and columns
Inlet scrubbers, separators, etc.
All metering equipment to include meters, meter runs,
strainers, etc.
All other pumps
All other tanks
B-5-27
-------
Table B.5-7. (continued)
Abbreviation Description
t
OTHER All other gas processing equipment
PPUMP Propane pump
PTANK Propane tank
PROD LINE All product lines
REFLUX PUMP All reflux pumps
REFRIGER All propane refrigeration system equipment
SWEETENER All gas sweetening equipment
B-5-28
-------
These exposure level data represent the most comprehensive and consistent set of
NORM data available for petroleum operations. However, much of the data were collected
at sites suspected of exhibiting some degree of radioactivity. The data were not collected in
a statistically designed sampling plan. The number of observations from oil and gas
equipment for a given geographic area may not be proportional to the actual amount of
operational equipment in that area. Hence, the data may not be typical of a randomly chosen
site and may tend to overstate the magnitude of the NORM occurrence.
NORM activity levels showed wide variability, both geographically and between items
of equipment in the same geographic area. Approximately 64 percent of the gas producing
equipment and 57 percent of the oil production equipment surveyed showed "zero" activity
values relative to background. The geographic areas with the highest equipment readings
are the entire gulf coast crescent (Brownsville, Texas to the Florida panhandle), northeast
Texas, southeast Illinois, and a few counties in southern Kansas. The eastern gulf coast from
Mississippi to the Florida panhandle had the highest consistent NORM activity levels
surveyed in the entire United States.
NORM activity levels tend to be highest in specific types of equipment. Oil production
equipment with the highest NORM activity levels is typically the water handling equipment.
Median exposure levels for this equipment were measured to be in the 30 urem/hr to
40 urem/hr range (about 5 times background). Gas processing equipment with the highest
levels includes the reflux pumps, propane pumps and tanlca, other pumps, and product lines.
Median radiation exposure levels for this equipment were measured to be in the 30 urem/hr
to 70 urem/hr range. For both oil production and gas processing equipment, a few
measurements were made of radiation exposure levels in excess of 1 mrem/hr.
B-5-29
-------
5.5 SUMMARY OF OIL AND GAS NORM SECTOR
The generic oil and gas scale site is assumed to be located in the state of Texas. The
state of Texas is known to have the highest number of oil and gas production wells. Although
much of the oil and gas production equipment containing NORM is presently stored in
controlled areas, some companies are now cleaning the equipment and proposing to dispose
of the NORM at disposal sites. Therefore, the risk assessment for this sector is based on the
disposal of oil and gas scale, and sludge waste at a disposal site. It is assumed that there
are six (6) regional disposal facilities, based on the volumes of waste and wide distribution
of the oil and gas production industry. The regional disposal facility is assumed to contain
767,000 cubic meters of such wastes. The facility is assumed to have a designated waste
disposal area of 160,000 square meters, with a depth of 4.8 m. It is also assumed that the
site is located near surface stream and that the region is underlain by an aquifer.
5.5.2 Population Exposure
The population density near and around the site is assumed to be the average for the
state of Texas, at 64 persons per square mile (BOC87).
5.53 Radionuclide Concentrations
Elevated concentrations of uranium and thorium and their radioactive daughter
products are often present in petroleum bearing geological formations. The uranium and
thorium are highly insoluble and, as oil and gas are brought to the surface, remain mostly
in place in the underground reservoir. However, radium is slightly soluble and may be
transported with liquid phases to the surface where it is deposited with scale and sludge on
the inside surfaces of oil and gas production piping and equipment. The concentration of
radium in scale and sludge depends on its concentration in the underground petroleum
B-5-30
-------
formation, on th : physical and chemical characteristics of the formation, and on changes in
temperature an< pressure as the liquid phase is brought to the surface.
The high 3t concentrations of radium are typically found in hard scale deposits that
form on the insi es of pipes and valves. The radium concentration in the scale is associated
with the direct ] reripitation of minerals from the liquid phase and can range up to several
thousand pioocu ies per gram of scale material. Median concentrations in scale are much
lower, in the ra ge of tens or hundreds of picocuries per gram. Radium concentrations in
granular deposii . and sludge are also much lower than concentrations in pipe scale, for the
purpose of *>»» ; ssessment, an average total radium concentration of 210 pCi/g is assumed
(155 pCi/g for R -226 and 55 pCi/g for Ra-228).
B-5-31
-------
B.5 REFERENCES
API90 Management and Disposal Alternatives for JORM Wastes in Oil Production
and Gas Plant Equipment, RAE-8837/2-2, pi spared by Rogers and Associates
Engineering Corporation for American Petn te,um Institute, May 1990.
API89 Otto, G.H., A National Survey on Naturally Occurring Radioactive Materials
(NORM) in Petroleum Producing and Gas Processing Facilities, American
Petroleum Institute, Dallas, Texas, July 19* ).
API87 Measurement Protocol for the Occurren« j of LSA Material, American
Petroleum Institute, Dallas, Texas, March 1 >87.
BAI88 Bailey, E., Texas Department of Health, Au -tin, TX, telephone conversation,
March 10, 1988.
BEL60 Bell, K.G., 1960, Uranium and Other Trace 1 lements in Petroleums and Rock
Asphalts, U.S. Geological Survey, Profession u Paper 356-B.
BLISS Buss, W.A., (EPA, Las Vegas) Memoran um to Mr. M. Mardis, (EPA,
Washington, D.C.), February 3, 1988.
BOC87 Bureau of Census, Statistical Abstract of le United States - 1988, 108th
Edition, Department of Commerce, Washing .on, D.C. 1987.
CPD87 Conference of Radiation Control Program Di ectors, Regulation and Licensing
of Naturally Occurring Radioactive Material , Part N of SSRCR, Draft 5, May
1987.
CRC88 Conference of Radiation Control Program Di ectors, Regulation and Licensing
of Naturally Occurring Radioactive Mat rials (NORM), June 6, 1988,
Frankfort, KY.
DEQ89 Louisiana Department of Environmental Qu iity, Regulation and Licensing of
Naturally Occurring Radioactive Materials (1 ORM), Title 33, Part XV, Nuclear
Energy, Adoption of Permanent Rule for N< RM, September 20, 1989, Baton
Rouge, LA.
EIA88 Energy Information Agency, Petroleum Marl 3ting Annual -1987, Department
of Energy, DOE/EIA-0487(87), Washington, 3.C., October 1988.
EPF87 E&P Forum, Low Specific Activity Scale Ori, in, Treatment and Disposal E&P
Forum, U.K., London Report No. 6 March 1 87.
FUE88 Fuentes, E.S., State Department of H alth, Jackson, MI, telephone
conversation, February 19, 1988.
B-5-R-1
-------
JOH73 Johnson, R.H., D.E. Bernhardt, N.S. Nelson, H.W. Calley, Assessment of
Potential Radiological Health Effects from Radon in Natural Gas,
Environmental Protection Agency, EPA 520/1-73-004, Washington, D.C., 1973.
NCR87 National Council on Radiation Protection and Measurements, Exposure of the
Population in the United States and Canada from Natural Background
Radiation, Report No. 94, Bethesda, MD, December 1987.
MAR87 Martin, J.C., Regulation and Licensing of Naturally Occurring Radioactive
Materials (NORM) in Oil and Gas Exploration and Producing Activities,
Proceedings of Conference of Radiation Control Program Directors Annual
Meeting, Boise, Idaho, May 21, 1987, American Petroleum Institute, Dallas,
Texas, June 1987.
MCA88 McArthur, A., Development and Operation of a NORM Processing and Disposal
Facility for the U.S. Oil and Gas Industry, published in CRCPD Publication
88-2,19th Annual National Conference on Radiation Control, May 18-21,1987,
Boise, Idaho, Conference of Radiation Control Program Directors, Frankfort,
KY, 1988.
MIL88 Miller, H.T., Disposition of Naturally-Occurring Radioactive Material in Crude
Oil Production Equipment, Chevron Corp., San Francisco, CA, presented at the
Annual Meeting of the Health Physics Society, Boston, MA, July 4-8, 1988.
MIL87 Miller, H.T., Radiation Exposures in Crude Oil Production Chevron Corp., San
Francisco, CA, presented at the Annual Meeting of the Health Physics Society,
July 5-9, 1987, Salt Lake City, Utah.
PET88 Petroleum Independent, published by Petroleum Independent Publishers, Inc.,
Washington, D.C. September 1988.
PIE55 Pierce, A.P., J.W. Mytton, and G.B. Gott, Radioactive Elements and Their
Daughter Products in the Texas Panhandle and Other Oil and Gas Fields in
the United States, Geology of Uranium and Thorium, International Conference,
1955.
Porter, C.R., (EPA, EERFL), letter to Mr. E.S. Fuentes, State Department of
Health, Jackson, MI, January, 1987.
Safety Analysis for the Disposal of Naturally-Occurring Radioactive Materials
in Texas, Rogers and Associates Engineering Corporation report to the Texas
Low-Level Radioactive Waste Disposal Authority, Report RAE-8818-1, Salt
Lake City, Utah, October 1988.
SCA88 SC&A, Inc., Technical Supplements for the Preliminary Risk Assessment of
Diffuse NORM wastes - Phase I, prepared by SC&A, Inc. for the
Environmental Protection Agency, under contract No. 68-02-4375, October
1988.
POR87
RAE88
B-5-R-2
-------
TDH89 Texas Department of Health, Naturally-Occurring Radioactive Material in Pipe
Scale, Interim Policy, Austin, TX, August 9,1989, Draft.
UK85 Guidelines for Operators on Naturally Occurring Radioactive Substances on
Offshore Installations, U.K. Offshore Operators Association Limited, Series
No. 5, July 1985.
B-5-R-3
-------
B.6 WATER TREATMENT SLUDGES
6.1 INTRODUCTION
Using 1985 water consumption rates, typically 400 billion gallons per day were
withdrawn for use in land irrigation, distribution in public supply systems, industrial
applications, and electric power generation (BOC87). About 40 billion gallons per day were
used in public water supply and distribution systems alone. Assuming a U.S. population of
241 million, the daily consumption rate per individual is nearly 170 gallons. Since water
comes from streams, lakes, reservoirs, and aquifers, it contains varying levels of
naturally-occurring radioactivity. Radioactivity is leached into ground or surface water since
it is always in contact with uranium and thorium bearing geological deposits before being
withdrawn. The predominant radionuclides found in water include radium, uranium, and
radon, as well as their radioactive decay products.
For reasons of public health, water is generally treated to ensure its safety for public
consumption. Water treatment includes passing the water through various types of niters and
devices which rely on chemical processes to remove impurities and organisms. If water with
elevated radioactivity is treated by such systems, there exists the possibility of generating
potentially radioactive wastes even if the treatment system was not originally intended to
remove radioactivity. Such wastes include filter sludges, ion-exchange resins, granular
activated carbon, and reject water from filter backwash.
Many municipal and private supply systems process water containing elevated
radionuclide concentrations, most commonly radium and uranium (GIL84). 'While some
treatment plants apply processes directed at specifically removing certain radionuclides from
water, radium is most commonly removed by cation-exchange resins and a lime-softening
process (HAH88). As a result of these processes, sludge may contain elevated radionuclides
concentrations, thereby creating a potential source of NORM wastes.
The purpose of this section is to characterize the concentration and inventory of
naturally-occurring radionuclides in water treatment sludge and the methods used to dispose
B-6-1
-------
of such sludge. The description also pres nts data and information on the types and volumes
of sludge, physical properties, disposal n luirements, and current and projected use of sludge
in agricultural applications. These dat i are used in Chapter D of this report to assess
potential radiation exposures to member . of the general public and critical population group.
6.2 OVERVIEW OF WATER SUP1 LY SYSTEMS
6.2.1 Areas of Elevated Water Radi nuclide Concentrations
There are about 60,000 public w; ;er supply systems serving the entire population of
the United States and about 47,700 relj on ground water sources (LON87, HES85, GIL84).
More than 90 percent of the ground wai ;r supply and distribution systems serve less 3,300
people (HES85). Since the majority of le municipal water supply systems in the United
States rely on ground water sources, tl a presence and distribution of naturally occurring
radionuclides in water have been the su >ject of several studies. The results of these studies
have shown that certain regions
-------
f om 0.1 to 0.5 pCi/L (HES85). The Ra-226 population weighted average concentration in
c immunity drinking water supplies is estimated to range from 0.3 to 0.8 pCi/L for Ra-226.
1 ie results of the National Inorganics and Radionuclide Survey (NIRS) indicate a higher
v sighted average of 0.905 pCi/L (LON87). Five states were noted to have still higher average
c ncentrations ranging from 1.27 to 5.29 pCi/L (LON87). These states are Georgia, Illinois,
I innesota, Missouri, and Wisconsin.
There is less definitive information and data on the presence of Ra-228 in ground
\ ater. Typically, Ra-228 concentration is noted as the ratio of Ra-228 to Ra-226 activity. The
I a-228 to Ra-226 ratio has been reported to vary from 0.2 to 5, but a ratio of 1.2 is generally
t .ought to be representative of average conditions (EPA86a, HES85). The major reason for
t .e higher Ra-228 concentration is that the average crustal thorium and uranium activity
r itio is about 1.2 to 1.5. Natural geochemistry enrichment or depletion processes may either
i crease or decrease this ratio. Accordingly, the Ra-228 ground water concentration is, on the
i rerage, believed to be slightly higher than Ra-226. The Ra-228 to Ra-226 ratio of 1.2 is also
I ilieved to characterize the distribution of these two radionuclides in surface waters (HES85).
1 he Ra-228 population weighted average concentration in community drinking water supplies
1 estimated to range from 0.4 to 1.0 pCi/L (HES85, EPA86a). The results of the NIRS survey
i .dicate a higher weighted average concentration of 1.41 pCi/L. Three states were noted to
} we higher averages ranging from 1.82 to 4.24 pCi/L (LON87), these states are Illinois,
T .innesota, and Wisconsin.
Uranium is known to be present in both surface and ground water sources. Natural
v ranium is comprised of U-238 (99.27 percent natural abundance), U-235 (0.72 percent), and
I -234 (0.006 percent). Uranium activity as high as 652 pCi/L was observed in both surface
i id ground water samples with a few supply systems exceeding 50 pCi/L (EPA86a, COT83).
1 lie average uranium concentrations in surface and ground water are believed to be about
3 and 3 pCi/L, respectively (COT83). The isotopic ratio of U-234 to U-238 is known to vary,
\ ith notably higher concentrations of U-234 in both surface and ground waters. The higher
I -234 concentration is due to the alpha recoil process which enhances the mobilization and
£ ilubility of the decay product (U-234) when compared to the parent (U-238). Ratios as high
i 3 28 have noted, but most often the ratios are found within a narrower range of 1 to 3
( IES85). The population weighted average uranium concentration in community drinking
^ ater supplies is estimated to range from 0.3 to 2.0 pCi/L (HES85, EPA86a).
B-6-3
-------
The presence of radon in ground water is known to vary significantly, sometimes over
six orders of magnitude that of Ra-226. The geometric mean of ground water radon
concentration is nearly 1,000 pCi/L (HES85, LOW88). For radon, the population weighted
average is believed to range from 194 to 780 pCi/L (LON87, COT87).
i
In geological terms, the United States may be divided into 11 regions. Based on the
results of an extensive water sampling and analyses program, two such regions, the North
Central and the Coastal Plain, have been identified with elevated radionuclide (primarily
Ra-226 and Ra-228) concentrations in drinking water supplies (COT83, COT84, HES85,
LOW88). The results of this study indicate that elevated radionuclide concentrations above
5 pCi/L were most often (75 percent of the instances) noted in two regions, the Piedmont and
Coastal Plain Provinces and North Central Region. The 5 pCi/L guideline for the combined
presence of Ra-226 and Ra-228 has been established by the EPA for drinking water under
the Safe Drinking Water Act (EPA76). By focusing on geological formations and aquifers with
elevated radionuclide concentrations, it is possible to identify regions which would result in
the production of significant volumes of water treatment sludge.
North Central Region - The North Central Region contains portions of Illinois, Iowa,
Minnesota, Missouri, and Wisconsin. It is estimated that there are 355 public water supply
systems in this region exceeding 5 pCi/L for both Ra-226 and Ra-228 (HES85).
Piedmont and Coastal PI"'" Provinces - The Piedmont and Coastal Plain
Provinces include portions of New Jersey, North Carolina, South Carolina, and Georgia. It
is estimated that about 200 public water supply system in this region exceed the 5 pCi/L, as
defined above (HES85).
Other Areas - Other areas reported to have radium concentrations in excess of 5
pCi/L include portions of Arizona, New Mexico, Texas, Mississippi, Florida, and
Massachusetts. The distribution of groundwater sources containing elevated levels of
naturally- occurring radionuclides tend to be located in regional clusters, dependent on the
presence of smaller geological formations. The estimated number of public water supply
systems exceeding 5 pCi/L is approximately 80 (HES85).
B-6-4
-------
It has been estimated that at least 500 water supply systems are known or suspected
to exceed the 5 pCi/L concentration guidelines (EPA86a, HES85). For the regions and areas
characterized above, it is estimated that 635 systems exceed the EPA limit. It is also
suspected that there might be some undetected systems which have elevated water
concentrations (HES85). For the purpose of this report, it is assumed that about 10 percent,
or 64 systems, have yet to be identified. Accordingly, it is assumed that 699 (rounded off to
700) water supply systems exceed the EPA concentration standards.
6.2.2 Water Treatment Technology
A summary of the number and size of public water supply systems is presented in
Table B.6-1 for the United States (EPA86b). Many of these systems employ a variety of water
treatment processes to improve water quality. Undesirable tastes and odors are removed by
aeration. Bacteria are destroyed by the addition of a few ppm of chlorine and excessive
hardness is reduced by the use of ion- exchange resins and lime. Table B.6-2 presents a
summary of water treatment systems which have been found to be effective in removing
radioactivity (EPA88).
Lome softening is used on larger supply systems to soften water by the addition of
calcium hydroxide. The calcium hydroxide raises the pH which causes the calcium and
magnesium to precipitate. The precipitate, along with suspended solids, are removed by
sedimentation and nitration. During this process, 80 percent to 90 percent of the radium in
the water is also removed (HAH88). This process typically produces about 4 cubic yards (3.1
m3) of dewatered sludge per million gallons of processed water. Prior to dewatering, the
sludge is about 2 to 5 percent solids. After dewatering, the sludge is about 50 percent solids
(EPA86b, PAR88).
Ion-exchange resins are used on smaller water supply systems to soften water by
replacing Ca and Mg ions with Na ions. In the process, about 95 percent of the radium is also
removed (HAH88). However, the resins are usually backwashed for reuse rather than being
disposed. The backwash water, which contains the radium, is typically discharged to storm
sewers, underground injection wells or septic tanks, or is backwashed to another
ion-exchange column for the selective removal of radium. As can be noted, wastes from water
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Table B.6-1 Numbers of public water system* and populations served
by sources and size category«(a)
Surface Water
Ground Water
System
Category
1
2
3
4
5
6
7
8
9
10
Population
per System
(000)
25-100
101-500
501-1K
1K-3.3K
3.3K-10K
10K-25K
25K-50K
50K-75K
75K-100K
>100K
Total:
Total Pop.
(000)
243
880
1,506
4,673
10,628
12,697
16,086
10,310
10,254
89,960
157,281
No. of
System;
4,596
3,544
1,770
2,425
1,841
879
500
220
139
278
16,192
Total Pop.
(000)
5,020
11,424
12,118
12,836
15,517
13,684
10,090
5,566
1,720
12,552
101,427
No. of
Systems
130,091
48,004
14,599
7,119
2,801
891
313
92
21
60
203,991
(a) From Regulatory Impact Analysis for Drinking A rater Regulations, EPA Office of
Drinking Water (EPA86a).
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Table I .6-2. Summary of treatment technologies for removal of
naturally-occurring radionuclides from water.(a)
Treatment
Technology
Cation
exchange
Anion
exchange
Lome
softening
pitation with
BaSo4
Selective
sorbents
Activated
alumina
Granular
activated
carbon
Aeration
Contaminant
Removed
Radium
Uranium
Radium
Uranium
Radium
Uranium
Radon
Uranium
Radium
Radon
Removal
Efficiency
85-97%
95%
90%
85-90%(b)
Wastes
Produced
Reverse
osmosis
Electro-
dialysis
Greensand
Copreti-
Radium
Uranium
Radium
Uranium
Radium
Radium
90%
90%
56%(c)
95%
90+%
90+%
96%
95%
Rinse & backwash water, brine
regenerant solution
(50-3, 500 pCi/L Ra)
Rinse & backwash water, brine
regenerant solution (25 mg/L U)
Sludge from tanks (6-9 pCi/g Ra; 1-10
pCi/g U), filter backwash (6-50 pCi/L
Ra), supernate (21-24 pCi/L Ra) from
setding or concentrating sludge &
filter backwash
Reject water (7-38 pCi/L Ra)
Reject water
Solids & supernate from filtration
backwash (21-106 pCi/L Ra)
Sludge from tanks, filter backwash,
supernate from settling or
concentrating sludge & filter
backwash
Selective sorbent with high levels of
radium (110,000 pCi/g)
Rinse & backwash water, regenerant
solution
Granular activated containing radon
decay products, uranium, & possibly
radium
Radon released to air
(a) Data ex racted from EPA82, EPA86b, and REI85.
(b) May be ncreased to 99% by the presence or addition of magnesium carbonate to the
water.
(c) May be ncreased to 90% by passing the water through a detention tank after the
addition of potassium permanganate prior to filtration.
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treatment systems may contain elevated radionuclide concentrations, at times exceeding
2,000 pCi/g for Ra-226.
The other systems (such as reverse osmosis) listed 'in Table B.6-2 are either not in
widespread use or generate a liquid waste product rather than sludges. Systems designed
specifically for the removal of radium are available but are currently not in widespread use.
Other types of water treatment processes are also known to remove radioactivity, but these
methods have not been widely evaluated. For example, flocculation and coagulation when
combined with nitration are believed to be effective in removing radionuclides with higher
valences (DYK86). Such systems are widely used and, consequently, there is a potential that
significant quantities sludge may be generated by this treatment process.
Table B.6-3 presents a summary of water treatment systems most often used by 211
water utilities (AWA87). The results shown are based on a 1985 survey conducted by the
American Water Works Association. A total of 184 utilities reported the use of 20 different
water treatment techniques and noted that two or more treatment methods were typically
used at the same time. Furthermore, 27 utilities (13 percent) reported using no treatment
methods at all. Four types of treatment methods most often (85 percent) used, included
chemical treatment, filtration, coagulation and flocculation (as one), and sedimentation.
Among these treatment methods or systems, all but two are especially relevant to the NORM
issue because they are widely used, generate sludge, and are known to remove radioactivity
from water (HAH88, PAR88, REI85, SOR88, DYK86). The two remaining treatment methods,
aeration and chemical treatment, generate little or no sludge at all (PAR89, LOW87).
6.3 WATER TREATMENT WASTE GENERATION
6.3.1 Water Treatment Waste Generation
As was noted earlier, there are many factors which govern how much waste a water
utility may generate. The major factors include water quality, water use, and type of water
treatment system. For the purpose of this assessment, waste or sludge generation rates will
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Table B.6-3. Distribution of water treatment systems reported in use
by 211 water utilities surveyed in 1985.(a)
Tvue of Svstem
Chemical
Filtration
Coagulation and flocculation
Sedimentation
Lime and soda lime
Aeration and volatilization
Ion exchange and activated charcoal
Note
1
2
3
4
Total(b):
Cited Use
253
111
86
76
34
33
25
618
Percent of Total
40.9
18.0
13.9
12.3
5.5
5.3
4.1
100.0
(a) Based on 184 utilities reporting the use of 20 water treatment techniques. A total of
27 utilities (13%) reported using no treatment methods at all. Information and data
extracted from the 1985 Water Utility Operating Data (AWA87).
(b) Utilities typically use several treatment methods at the same time, hence the total
number of systems cited exceeds the total number of utilities responding to the survey.
Notes:
1. Includes ozone, chlorine, chlorine dioxide, chloramine, and fluoridation.
2. Consists of direct, slow and rapid sand, and pressurized filtration.
3. Conventional aeration for taste and odor and aeration for removal of volatile organic
4.
Includes ion-exchange softening, resin beds for organics, and granulated and
pulverized activated charcoal for filtration and removal of organic contaminants.
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be based on the results of two surveys conducted by the American Water Works Association
(AWWA), which conducts periodic surveys of the largest water utilities.
A summary of the 1984 and 1985 surveys results 'are shown in Table B.6-4. The
survey results for 1984 encompass 430 water utilities which served 104 million people
(AWA87). The 1985 survey results reflect a more modest population of 11 million people and
211 utilities (AWA87). The water consumption rates per capita were nearly identical for both
years, 176 and 163 gallons in 1984 and 1985, respectively. The total amount of water
processed in each year was reported to be 25.3 billion m3 in 1984 and 2.4 billion m3 in 1985.
The total amount of sludge generated between both years is expected to be different since
only half as many utilities responded in the 1985 survey and only a fraction of those
generated sludge. A breakdown is also given for six types of sludge disposal methods. As can
be noted, the largest quantities of sludge are disposed in lagoons, landfills, and by land
application. The last method listed as "Return to head of treatment plant/supply" is really not
a disposal method, but rather a recycling method. Only the settling sludge is disposed of
while the decanted water is recycled. The sludge content is about 3 percent by weight.
In general, the results show a degree of internal consistency between both survey even
though the number of utilities surveyed in 1984 served about ten times as many people. The
only exception being that, on the average, the amount of sludge generated per utility is
different only by a factor of three rather than ten. The discrepancy may be due to a difference
in the distribution of utilities surveyed in 1984 and 1985.
Within the context of this assessment, two parameters are thought to provide better
indices to estimate, in the aggregate, the potential sludge generation rates for all utilities.
These are: 1) the sludge generation rate per capita, and 2) sludge generated per unit volume
of processed water. The average of both years is used, see Table B.6-4. It is assumed that the
total U.S. population is 241 million and that water consumption by public supply systems is
55.2 billion m3 per year (BOC87). Given the above, the yearly sludge generation rates are
estimated to be:
Based on
sludge/capita: 13 kg 241 million 3.1 million MT
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Table B.6-4. Summary of water utilities operating characteristics for
1984 and 1985(a)
Parameter
Utilities Surveyed Response
(No7%):
Population Served:
Water Production (in billion m3)
Total:
Ground:
Surface:
Purchased:
Average water use per capita:
Sludge Disposal (in thousand MT)
Sewer:
Lagoon:
3rd Party Landfill:
Utility T.and fill-
Land Application:
Return to head of plant/supply:
Total:
No. of utilities producing sludge:
Calculated Parameters
Sludge per capita:
Sludge per utility:
Sludge per unit of processed water:
1984 Data 1985 Data
600
430/72
600
211/35
104 million 11 million
25.3
6.3
16.8
2.2
2.4
0.7
1.4
0.3
176 gal/day 163 gal/day
32
180
42
100
100
550
1,100
253
11 Kg
4,300 MT
44g/m3
4.3
100
20
20
13
2.5
160
109
15 Kg
1,500 MT
67g/m3
(a) Parameters and data taken from the 1984 and 1985 Water Utility Operating Data
(AWA86, AWA87). Numbers may not add up to total because of the rounding off
process.
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Based on
sludge/m3 of
water processed: 56 g/m3 55.2 billion m3 3.1 million MT
/
These results indicate that about 3 million metric tons (MT) of sludge are generated yearly
in the United States from all utilities. In attempting to cap the maximum yearly sludge
generation rate from all sources, the higher values shown in Table B.6-4 are used instead.
These are 15 Kg of sludge per capita and 67 g of sludge per m3 of processed water. Applying
these new parameters indicates that, other things being equal, 3.7 million MT of sludge are
produced yearly. Accordingly, the total amount of sludge which could be considered a
potential NORM waste is probably much less than 3.7 million MT since not all utilities
process water with elevated naturally-occurring radioactivity. As noted earlier, it was
assumed that only 700 water utilities are suspected of generating NORM wastes.
6.3.2 Water
The AWWA 1984 survey results are used to characterize the sludge disposal practices
of utilities in 29 selected states. The 29 states were chosen based on information which
indicates that several utilities in such states are known or suspected to process water with
elevated radionuclide concentrations. The selection of these states is based on a review of
studies and surveys conducted by Longtin, Hess, and Cothern (LOW88, LON87, HES85,
COT83, and COT84). The states are identified in Table B.6-5. The sludge generation rates
were taken from the 1984 AWWA survey since it captured a greater number of utilities than
the one of 1985. The results are summarized in Table B.6-5.
A review of Table B.6-5 indicates that although 54 percent of the sludge that is
returned to the head of the water treatment plant, only 3.5 percent of this amount is sludge
that requires disposal. For the remaining methods, 42 percent of the sludge is disposed in
lagoons, and 29 percent is disposed in utility and third party landfills. About 20 and 5
percent of the sludges are disposed, respectively, by application on agricultural land and into
sewers. A total of 831,000 metric tons was generated by 183 utilities and 392,000 metric tons
of sludge was disposed in the true sense. On the average, each state and utility disposed
13,500 and 2,140 metric tons, respectively.
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Table B.6-5. Sludge disposal practices and quantities for 183 utilities
in 29 selected states.(a>
Disposal Method(b) Quantity (MT) Percent of Total
Return to head of
plant/supply*0*
Total: (452,000)
Sludge Only: 13,600
Lagoon: 163,000
Land Application: 80,000
Utility Landfill: 74,000
Third Party Landfill: 40,900
Sewer: 20,800
Total Amount: 831,000
Total Disposed: 392,300
(54.5)
3.5
41.6
20.4
18.8
10.4
5.3
100.0
CALCULATED DATA
Average per state:
Average per utility:
Generation (MT)
29,000
4,600
Disposal (MT)
13,500
2,140
(a) Data extracted from the 1984 Water Utility Operating Data (AWA86). Numbers are
rounded off.
(b) Data characterizing disposal practices of 183 utilities located in 29 states. The states
include: AZ, CA, CO, CT, FL, GA, IL, IN, IO, KA, MA, MN, MI, MO, NB, NE, NH, NJ,
NY, NC, OK, PA, SC, SD, TX, UT, WA, WI, and WY.
(c) Only 2 to 5% of the total amount is actually sludge, the balance is decanted water.
Three percent is assumed here in estimating the sludge volume destined for disposal.
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Three methods are used to estimate the amount of sludge which may be categorized
as a NORM waste. The first method simply assumes that all 700 utilities generate sludge at
2,140 MT per year. This yields a total yearly disposal rate' of 1.5 million MT. This amount
is believed to be too high since it represents 50 percent .of the total amount of sludge
generated by all sources. This estimate is also unrealistic since it assumes that all utilities
generate NORM wastes regardless of the source of water and type of treatment systems.
In the second method, if one were to assume that the disposal rate per state (13,500
MT) is representative of overall practices, then the corresponding amount requiring disposal
is nearly 400,000 MT, based on the 29 selected states. This amount of sludge is lower, but
is also too high since it assumes that all utilities generate NORM wastes regardless of the
source of water and type of treatment systems.
The third approach involves using the average water utility sludge generation rate
based on the 1984 survey data and adjusting it to reflect specific factors which characterize
this NORM sector. The average sludge generation rate is adjusted for the fact that: 1) about
80 percent of the water supply systems rely on ground water, 2) about 90 percent of the users
do not need finished or potable water, and 3) that about 28 percent of the utilities use water
treatment systems which may remove naturally-occurring radioactivity. It is assumed that
such treatment systems include filtration (18 percent), lime and soda lime (6 percent), and
ion-exchange and activated charcoal (4 percent) (see Table B.6-3 for details). An overall
removal efficiency of 85 percent is assumed-for these systems based on the data given in
Table B.6-2. An average sludge generation rate of 2,140 MT was previously estimated, see
Table B.6-5. Accordingly, it is estimated that, on the average, about 314 MT of sludge and
52 MT of spent resin and charcoal beds will be generated yearly by such a utility. Since it
was assumed that there are 700 suspect water utilities in the continental U.S., the total
yearly NORM waste generation is estimated to be 256,000 MT, which is rounded off to
260,000 MT.
In view of these broad assumptions, it can be noted that the total amount of sludge
and spent resins and charcoals beds which may be classified as a NORM waste is perhaps
on the order of 260,000 MT, and possibly less. The earlier estimate of 1.5 million metric tons
is believed to be much too high since it does not reflect some of the important characteristics
B-6-14
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of this NORM sec- jr. As noted earlier, there are water treatment systems which have not
been considered ii this estimate, but which are believed to generate sludge as a potential
NORM waste. For example, flocculation and coagulation when combined with filtration are
thought to be an e ective process to remove radionuclides of higher valences (DYK86). Such
systems are widel: used and, consequently, there is a potential that significant quantities of
sludge may be g< aerated by this treatment process. Finally, it is suspected that the
characteristics oft ich NORM wastes, including spent resin and charcoal beds, fall within a
spectrum ranging from wastes with very low to those with very high radionuclide
concentrations.
Given that these estimates are based on data for a single year and lack any
information chara< arizing disposal practices over longer time periods, this range is assumed
to bracket the am ants of sludge which could be considered a potential NORM waste. It is
also not clear from past survey data what is the total number of utilities which have passed
the EPA drinking /ater standards for finished water, but still may result in the generation
of water treatmen sludges at concentrations which may still be of concern in the context of
this assessment. / Ithough the resulting radionuclide concentrations may be relatively low
when compared tc instances with elevated levels, however, it is most likely that such type
of wastes are bein; generated in much larger quantities. For the purpose of this assessment,
it is assumed thi : 260,000 metric tons of sludges and spent resins and charcoals are
generated yearly 1 / this NORM sector.
6.3.3 Utilization of Water Treatment wastes
About 20 F :rcent of the total amount of sludge generated yearly is put into useful
application, e.g., le id spreading and injection into agricultural fields. Other disposal methods,
which include the Dlacement of sludge in landfills (29 percent) and in lagoons (42 percent),
are not considers as utilization practices. It could, however, be argued, that given the
nutrient propertie of sludge it is conceivable that areas which were once disposal landfills
or lagoons could 1 a later used for agricultural production. Accordingly, this assessment
considers both dis josal into landfills and agricultural applications.
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Potentially contaminated waste byproducts of drinking water treatment may include
lime sludge, backflush water, spent ion-exchange media, and sand filter elements. Very little
or only patch work regulatory guidance exists controlling the disposal of such NORM wastes.
However, future disposal practices may rely to a greater extent on discharging backwash
waters to lagoons or ponds. Such practices will result in the accumulation of radium in
bottom sediments which may represent an additional source of NORM wastes. The ponds
may have to be periodically dredged and the bottom sediments may require proper and
permanent disposal.
Storm Sewer - Material discharged into a typical storm sewer is routed to a natural
water body, in which sludge may accumulate in aquatic sediments depending upon the flow
rate of the water body and addition of natural waters. Liquid effluent standards applicable
to Nuclear Regulatory Commission (NRG) licensees have been established under Title 10,
Part 20 of the Code of Federal Regulations (10 CFR 20):
CRa-226/3° * cRa-228/3° are less than 1, where;
CRa-226 = concentration of soluble Ra-226 in the discharge water (pCi/L),
and
CRa-228 = concentration of soluble Ra-228 in the discharge water (pCi/L).
The radium concentrations can only be averaged over a period of one year (NRC88). State
agencies adopting the federal standards have adopted the NRG limits (HAH88).
Sanitary Rawer . Sludge and other waste water residues discharged into sanitary
sewer systems are ultimately treated at a sewage treatment plant. For releases into sanitary
sewers, the NRG regulations include the following criteria under 10 CFR 20:
1. The material must be readily soluble or dispersible in water,
2. The quantity of radium released into the system by the licensee in one
day does not exceed either:
a. The quantity which if diluted by the average daily quantity of
sewage released into the sewer by the licensee, will result in an
average concentration equal to 4 x 10"7 uCi/mL radium-226 and
8 x 107 uCi/mL radium-228, or
B-6-16
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b. 0.1 znicrocuries radium-226.
3. The quantity of radium released into the system by the licensee in any
one month, if diluted by the average monthly quantity of water released
by the licensee, will not result in an average concentration exceeding 4
x 10'7 uCi/mL radium-226 and 8 x 10'7 uCi/mL radium-228; and
4. The gross quantity of licensed and other radioactive material, excluding
carbon-14 and tritium, released into the sewerage system by the
licensee does not exceed one curie per year.
The state of Wisconsin has implemented standards for sanitary sewer discharge in the
form (WIS85):
CRa-226/40° * cRa-228/80° are less than 1, where;
CRa-226 = concentration of soluble Ra-226 in the waste water (pCi/L), and
CRa-228 = concentration of soluble Ra-228 in the waste water (pCi/L).
The radium concentrations derived above may not be averaged over a period greater than one
month. In addition the total amount of radionuclide discharge in one year must not exceed
1 curie. As mentioned for storm sewer discharge, state agencies adopting these standards for
permitted facilities may enforce them.
Agricultural - Residual lime sludge from a water treatment plant is sometimes
dewatered and provided to farmers for free or a nominal fee. The sludge is spread onto a field
in a similar manner as other fertilizers, and tilled into the soil. Currently, only Wisconsin
and Illinois have regulatory programs that require testing of sludges and fields prior to
dispersal (HAH88, WIS88). Frequent application of sludges over an extended period of time,
or stockpiling may create significant accumulations of radionuclides. Because of .this concern,
some states are imposing limits on the amounts of radioactivity which may be introduced in
fields. For example, the state of Illinois authorizes the disposal of sludge in agricultural lands
provided that the combined concentration of sludge and soil will not increase the Ra-226 soil
concentration by more than 0.1 pCi/g (HAH88).
Landfill - The disposal of sludge at municipal landfills is not regulated by states other
Wisconsin and Illinois. At landfills, contaminated material is typically covered and
B-6-17
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compacted on a daily basis. Disposal site design features, such as a c ay lining or isolation
from useable aquifers, limit the transport of radionuclides out of the la idfill. Other features,
such as compacted clay layers placed above radium-contaminated ; ludges reduce water
infiltration and radon emissions. The radionuclides are, therefore, not likely to be available
for movement into the environment unless radionuclide teaching and tr msport are enhanced
by hydrogeological and meteorological conditions. Similarly, if former landfill sites were to
be subsequently used for residential housing or commercial dev lopment, then that
population could become exposed to higher radiation levels.
Deep-well Injection - Deep-well injection involves the pumping f sludge into a stable
geologic formation. The stability and immobility of the injected w; ste are governed by
parameters, such as the absence of fractures, minimal water infill -ation, and chemical
conditions which may alter the solubility of the radionuclides. Deep-v all injection is not in
common use and is specifically prohibited in Wisconsin and Illinois (H \H88). The EPA also
discourages this practices because of its potential detrimental imp ict on ground water
aquifers.
Non-Sewered Disposal - Non-sewered disposal typically involve.' the disposal of waste
water in private septic systems. Failure of these systems can ^ad to transport of
contaminants through certain geologic media. However, the scalt and environmental
consequences are estimated to be minimal.
With the current information, it is not possible to characterize < isposal practices and
waste inventories among storm sewer, sanitary sewer, and unsewere i releases, and those
that involve deep-well injection. It is also recognized that for the otk ;r identified disposal
practices there exists some uncertainty as to their representativeness 01 national level. Given
these varied disposal practices and information based on the surve; results of a limited
number of utilities, there exists a need to further characterize water tr atment methods and
disposal practices on a larger scale. Additional data correlating input w; ter volumes to output
waste concentrations would be useful in determining waste generation -ates on a nationwide
basis for a particular type of treatment process. The data would m ad to be based on a
representative number of water treatment plants utilizing a specific .reatment technique.
Studies of actual disposal methods in use by water utilities are also n eded to establish the
basis to form population risk models. It is understood that the An erican Water Works
B-6-18
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Association will initiate in late 1989 another survey of water utilities (AWA89). The survey
will target the 1,000 largest water utility in the United States. The results of this survey
should, in part, help resolve some of the questions raised above.
6.3*4 Twenty-Year Sludge Generation Estimates
For the purpose of estimating the 20-year inventory of NORM wastes, it is assumed
that 260,000 metric tons of sludge are generated yearly (see above discussion for more
details). The growth in water use is keyed primarily to population increase rather than other
indices, such as economic growth. It is also recognized that other factors may influence water
usage and the number and distribution of water utilities. For example, small water utilities
may go out of business, but the service must continue since the demand and population
remains. The service is usually taken over by a new or perhaps larger utility.
Similarly, as water demand increases, new demand may be placed on existing systems
and a greater emphasis may be placed on recycling water rather than increasing water
withdrawal rate from existing aquifers. A larger fraction of the water supply may also come
from surface water bodies. Because of the presence of organic contaminants in surface
streams and lakes, utilities may be forced to adopt improved water treatment technologies
to meet more stringent regulatory requirements. The current water treatment technology
may also improve over time such that new treatment systems would extract more impurities
and generate more sludge. These factors would result in the generation of greater quantities
of sludge than current rates. Within the context of this study, it is not possible to estimate
the impact of improved technology and regulatory requirements on future waste generation
rates. Given that the yearly generation rate is already based on an upper estimate, no further
corrections are made other than for an increase in population growth.
The anmml U.S. population growth rate has been estimated to decrease over the next
20 years; from 0.99 percent for the ten- year period ending in 1990, to 0.71 percent from 1990
to 2000, and finally to 0.57 percent beyond the turn of the century (BOC87). An average
population growth rate of 0.76 percent is used here given these trends. Compounded over the
next 20 years, the population growth factor is 1.16. Accordingly, the total 20-year inventory,
B-6-19
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assuming a yearly sludge generation rate of 260,000 metric tons, is estimated to be 6 million
metric tons.
6A RADIOLOGICAL PROPERTIES OF TREATMENT SLUDGE
6.4.1 Radionuclide Concentrations
As was noted earlier, the predominant radionuclides found in water include radium,
uranium, and radon, as well as their radioactive decay products. For example, radium-226
concentration in surface water is known to vary from 0.01 to 1 pCi/L and from 0.5 to 25 pCi/L
in ground water (LOW88, HES85, COT84, COT83, REI85). Occasionally, these radionuclides
are found at still higher concentrations. For example, radium concentrations as high as 200
pCi/L have been reported, while in most instances the concentration is seldom above 50 pCi/L
(HES85). States with large numbers of water treatment plants processing raw water in
excess of 5 pCi/L are located in Illinois, Iowa, Missouri, Wisconsin, North Carolina, South
Carolina, and Georgia (LON87, HES85, COT84, COT83).
In general, the concentration of radium in sludge will depend on water quality, the
aquifer from which the water is withdrawn, water quality, water use, and the type of
treatment systems. More specifically, the following major factors will govern the
characteristics of sludge:
1. Presence of naturally-occurring radioactivity and radionuclide
concentrations in the water supply,
2. Radionuclide removal efficiency for a given water treatment system,
and
3. The amount of sludge produced per unit volume of water processed.
Assuming an overall average Ra-226 concentration of about 1 pCi/L, a radium removal
efficiency of 90 percent, and a sludge generation rate of 3.1 m3 per million gallons of water
treated (HAH88), the average concentration of Ra-226 in sludge is estimated to be about 1
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pCi/g. Correcting for the fact that dewatered sludge is about 50 percent water, the average
concentration of Ra-226 in dry sludge is about 2 pCi/g. This calculation yields a useful rule
of thumb, that is, about 1 to 2 pCi/g sludge is produced per pCi/L of Ra-226 in the water
supply. This estimate does compare favorably with measured values reported in the literature
(EPA76, HAH88). For example:
- Ra-226 Concentration -
Raw Water Lome Sludge
Location (oCi/L) (oCi/g dry)
Elgin, IL 5.6 6.1
Peru, IL 5.8 9.0
Wisconsin 1.0-5.3 2.1-32.8
Using the above calculational approach, it is concluded that the average Ra-226
concentration in sludge is comparable to that in soil (NCR87). However, this conclusion is
speculative and may need to be verified by a field survey and sampling program.
Although the average Ra-226 concentration in sludge is typically low, public water
treatment facilities which process water supplies with elevated Ra-226 concentrations are
expected to generate sludge with elevated levels of Ra-226. Based on data reported by states
exceeding the 5 pCi/L standards, the combined radium concentrations were noted to range
from 5 pCi/L to about 25 pCi/L, with an average of about 10 pCi/L (HES85). Since the ratio
of Ra-228 to Ra-226 is about 1.2 (HES85), the average Ra-226 concentration in water supplies
which exceed the current standards is about 4 pCi/L. Using the rule of thumb described
above, sludge from these systems may be expected to contain an average Ra-226
concentration of 4 to 8 pCi/g.
Radium selective resins, on the other hand, do generate wastes at much higher
concentrations, but in much smaller quantities. The radionuclide concentration in these
wastes is dependent upon the type of resins used, the amount of regenerant used, and how
frequently the resins are regenerated. The radionuclide concentration in resins and
regeneration wastes are known to vary. Field data indicates that radium concentrations
between 320 to 3,500 pCi/L were noted in the column rinse and brine. Average and peak
concentrations of 23 and 158 pCi/L, respectively, have been noted in regenerant wastes
(EPA88). Radium build-up in cation-exchange resins has been observed to average at about
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9 pCi/g, with peak concentrations ranging from 25 to 40 pCi/g. Given the broad variability
of ground and surface water concentrations, the uncertainty with the type and number of
water treatment systems being used, and their effective radionuclide removal efficiency, a
simple approach is used to estimate radionuclide concentration in sludge.
0
It has been shown that an approximate "rule of thumb" relationship for radium
concentration in sludge is given by two times the influent radium concentration in water.
Sludge concentrations of U-238, Th-230, Th-232, Th-228, and U-235 were calculated using
thia method, even though it has been shown that certain water treatment processes do not
remove uranium as efficiently as radium (REI85, EPA86a). The Pb-210 and Po-210 sludge
concentrations were estimated by assuming a radon emanation coefficient of 40 percent for
moist sludge. The average sludge radionuclide concentration is as follows:
Influent Resultant
Water - pCi/L Sludge - pCi/g
U-238 - 2.0 4.0
U-234 - 2.0 4.0
Th-230 - 0.1 0.2
Ra-226 - 8.0 16.0
Th-232 - 0.1 0.2
Ra-228 - 10.0 20.0
Th-228 - 0.1 0.2
U-235 - 0.014 0.03
Pb-210 - 4.8 10.0
Po-210 - 4.8 10.0
These influent concentrations represent radionuclide concentrations in excess of those
experienced by most water treatment plants. The variation of influent radionuclide
concentrations to the water treatment plant is based on solubility and chemical properties
of certain elements in the ground water. Such properties include the relatively low solubilities
of thorium ions, desorption of radium from certain geologic formations based on the ionic
strength of the groundwater, and the transport of uranyl ions (GIL84, SOR88).
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6.4.2 Radon Fh«
No readily available information was identified characterizing radon emanation rates
from such wastes. Radon emanation rates from sludge (including spent resins and charcoal
beds) are assumed to be nearly identical to that of typical soil?. For example, the NCRP notes
that for typical soils, an average radon emanation rate is about 0.5 pCi/m2-s per pCi/g
(NCR87). For an assumed Ra-226 concentration of 16.0 pCi/g (see above), the corresponding
radon flux rate is about 8 pCi/m2-s, other things being equal.
Radiation exposure rates associated with the disposal of sludge are expected to be
relatively low when compared to ambient background levels. For spent resin and charcoals
beds, exposure rates may, however, be much higher. For example, exposure levels as high as
several mR/h have been observed on charcoal and resin beds (LOW88). Depending upon the
source of radioactivity (radium vs. radon and its decay products), the radiation levels may
quickly decay with time. Given the disposal method and the mode of exposure, radionuclides,
and source to receptor geometry, it can be assumed that the resulting radiation doses may
be scaled up based on empirically derived exposure rate conversion factors for environmental
conditions. The conversion factors represent exposure rates for typical soils and include the
effects of gamma ray scatter, build-up, and self-absorption (NCR87). For example, the
conversion factors for the uranium and thorium decay series are 1.82 and 2.82 uR/h per
pCi/g, respectively. Assuming a Ra-226 (for U-238) and Ra-228 (for Th-232) concentration of
16 and 20 pCi/g, respectively, the total incremental exposure rate is estimated to be about
86 uR/h. The exposure rate would in fact be less since the decay series would not have had
the time to achieve secular equilibrium. In the United States, ambient exposure rates due
to terrestrial radiation are known to range from 3 to 16 uR/h (NCR87).
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6.5 GENERIC SITE PA 'JVMETERS AND SE 7TOR SUMMARY
This section presents a summary of the d£ :a and parameters which are used to
perform the risk assessmen of this NORM sector The radiological assessment model is
described in Chapter D. This :hapter also introduces parameters and assumptions which are
both generic and specific tc each NORM sector. ' 'his information is not presented nor
repeated here.
6.5.1 Generic Water Trea tnent Site
The generic water tre tment plant is assume i to be located in Illinois. This state has
been shown to have consist* itly elevated concentr. tions of Ra-226 and Ra-228 in ground
water (GIL84, HES85, LOI 87), it has a large a ricultural base, and is more densely
populated. Two scenarios are developed for this NOI M sector: 1) agricultural uses of sludge,
and 2) landfill disposal of sh ige. Due to the limite< information on non-sewer wastewater
discharge and deep-well injet ion, these disposal pat .ways will not be addressed here for the
purpose of this risk assessmt at It is assumed that alatively few water treatment facilities
dispose of sludge in this mac xer. Sanitary sewer slv Ige is typically treated at a wastewater
treatment plant Storm sewe disposal will not be di? :ussed due to limited information about
the practice and data charac erizing the mobility a.< d availability of radium in this kind of
aquatic environment. For tht purpose of this assessj lent, the two remaining options include
agricultural application or k idfill disposal.
Sludge is commonly ai plied or spread into agi cultural fields using methods which are
similar to those used for fe: ;ilizers. For sanitary : masons and to minimize surface water
runoff, states typically recon mend that the sludge -e injected or plowed under at the time
of application (WIS75, WIS8.' WIS88). For the purpt se of this assessment, it is assumed that
the sludge is either plowed nder or injected to a i x>t zone depth of 15 cm. The sludge is
assumed to be introduced ov ;r the entire acreage a id applied at rate of about 4.5 tons per
acre every other year for 20: ears (WIS75). The mod ;1 site for this scenario is assumed to be
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an average Illinois farm of 340 acres (BOC87). It is assumed that the field is bordered on one
side by a nearby stream and the region is underlain by an aquifer. The size of the field is
assumed to be square with dimensions of 1,200 m by 1,200 m. Given the application rate and
acreage, 1,390 MT of sludge is introduced during each application and a total of 13,900 MT
is disposed over a 20-year period. These quantities are simply rounded off to 1,400 and 14,000
MT, respectively.
MunicipalLandfillDisQosal
This scenario addresses the disposal of radium contaminated sludge into a typical
municipal landfill serving a large community. Since the water utility supplies water to a
small community, the utility is assumed to be using a third-party landfill rather than its own.
It is assumed that the landfill accepting the sludge is used for other purposes as well. A
12-inch cover material is placed over the sludge on a daily basis (WIS88). Since the landfill
was opened some years ago, it is assumed that the no special requirements were imposed on
the site regarding the installation of a leachate containment system. At closure, a 1 ft layer
of topsoil is placed over the fill area. Credit is taken only for the surface layer of the soil
cover. The landfill is assumed to be 40 acres (16 hectares). It is assumed that the field is
bordered on one side by a nearby stream and the region is underlain by an aquifer. The size
of the field is assumed to be square with dimensions of 400 m by 400 m. The sludges are
disposed by a water treatment plant creating 366 MT of sludge per year, based on the earlier
estimates. The total amount of sludge disposed over a 20-year time period is assumed to be
7,320 MT.
6.5.2 Population Exposure
The model site for this scenario is assumed to be located in a rural Illinois. The
population density is assumed to be that of the state of Illinois, at 210 people per square mile
(BOC87).
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6.5.3 Radionuclide Concentrations
The presence of radium in sludge depends upon the initial water Ra-226 and Ra-228
concentrations. In regions where water supplies exhibit elevated radioactivity levels, sludge
from, water treatment systems are expected to have higher radionuclide concentrations.
However, it has been shown that raw water with less than 5 pCi/L of total radium, when
processed, may produce a significant accumulation of radium in sludge. Given the broad
variability of ground and surface water concentrations, the uncertainty with the type and
number of water treatment systems being used, and their effective radionuclide removal
efficiency, a simple approach was used to estimate radionuclide concentration in sludge. A
rule of thumb was applied with which to convert influent water concentration to resultant
sludge concentration. The selected radionuclide concentrations (see Section 6.4.1) assumed
that the water (and consequently the sludge) originates from areas which are traditionally
high in naturally-occurring radioactivity.
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B.6 RE1 ERENCES
AWA89 Telephone Communication wit i Mr. Kurt Keely, September 27,1989, A aerican
Water Works Association, Dei ver, CO.
AWA87 American Water Works Ass< nation, 1985 Water Utility Operatic ; Data,
Denver, CO, 1987.
AWA86 American Water Works Ass< nation, 1984 Water Utility Operatic : Data,
Denver, CO, 1986.
BOC87 Department of Commerce, St itistical Abstract of the United States - 1988,
108th Edition, Bureau of Gen us, 1987.
COT83 Cothern, C.R., Lappenbusch,A r.L., Occurrence of Uranium in Drinkin ; Water
in the U.S., Health Physics J< irnal, Vol. 45X1), July 1983.
COT84 Cothern, C.R., Lappenbusch, W.L., Compliance Data for the Occur ence of
Radium and Gross Alpha-Par -de Activity in Drinking Water Supplit ; in the
United States, Health Physic: Journal, Vol. 46(3), March 1984.
DYK86 Dyksen, J.E., et al., The Capa >ilities of Standard Water Treatment P ocesses
to Meet Revised Drinking W iter Regulations, AWWA, Annual Co, ference
Proceedings, June 22-26, 198< , pp. 951-965, Denver, CO.
EPA76 Environmental Protection i gency, Determination of Radium } emoval
Efficiencies in Illinois Wate Supply Treatment Processes, Dlin< s EPA
prepared for the U.S. EPA, O Ice of Radiation Programs, May 1976.
EPA82 Environmental Protection Age icy, Disposal of Radium-Barium Sulfat Sludge
From a Water Treatment 'lant in Midland, South Dakota, T chnical
Assistance Program Report pi 3pared by Fred C. Hart Associates, Inc for the
U.S. EPA, Region VIII, Decen her 1982.
EPA86a Environmental Protection A: ency, 40 CFR 141 Water Pollution Control;
National Primary Drinking W ter Regulations; Radionuclides: Advanc : Notice
of Proposed Rulemaking, Fedt -al Register Notice, Vol. 51, No. 189, Se tember
20, 1986.
EPA86b Environmental Protection Ag ncy, Technology and Costs for Treatir ;nt and
Disposal of Waste byproducts by Water Treatment for Removal of Ii organic
and Radioactive Contaminant;, September 1986.
EPA88 Environmental Protection Ag ncy, Suggested Guidelines for the Dit x>sal of
Naturally Occurring Radiom elides Generated by Drinking Water Plants,
Waste Disposal Work Group, )ffice of Drinking Water, June 1988.
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GIL84
HAH88
HES85
LON87
LOW88
LOW87
NCR87
NRC88
PAR89
PAR88
REI85
SOR88
WIS75
WIS85
WIS88
Gilkeson, R. H., et f .., Isotopic Studies of the Natural Sources of Radium in
Groundwate in Illir >is, University of Illinois Water Resources Center, report
UILU-WRC- 34-183 j repared for the United States Department of the Interior,
April 1984.
Hahn, N. A. Jr., Dis osal of Radium Removed Prom Drinking Water, AWWA
Journal, Jul 1988.
Hess, C. T. e . al., Th Occurrence of Radioactivity in Public Water Supplies in
the United £ cates, I ialth Physics Journal, Vol. 48 (5), May 1985.
Longtin, J.F , Radoi . Radium, and Uranium Occurrence in Drinking Water
from Grouni water £ mrces, AWWA Journal, June 14, 1987.
Lowry, J.D. and S. B. Lowry, Radionuclides in Drinking Water, AWWA
Journal, Jul 1988.
Lowry, J.D. at al., 1 oint of Entry Removal of Radon from Drinking Water,
AWWA Joui lal, Ap: .1 1987.
National Co- ncil on ladiation Protection and Measurements, Exposure to the
Population a the Jnited States and Canada from Natural Background
Radiation, * CRP R< x>rt No. 94, December 1987.
Standards fc r Protec ion Against Radiation, U.S. Code of Federal Regulations,
Title 10, Pai : 20, Ja \uary 1988, as amended.
Telephone C
:ation with Mr. Marc Parrotta, Environmental Protection
Agency, Offi :e of Dr airing Water, Washington, DC, September 27, 1989.
Telephone C
ration with Mr. Marc Parrotta, Environmental Protection
Agency, Offi :e of Dr along Water, Washington, DC, September 14, 1988.
Reid, G. W. it al., T eatment, Waste Management and Cost of Radioactivity
Removal fro a Drinl ng Water, Health Physics Journal, Vol. 48, May 1985.
Sorg, T.J., : lethods for Removing Uranium from Drinking Water, AWWA
Journal, Jul r 1988.
Guidelines f >r the A >plication of Wastewater Sludge to Agricultural Land in
Wisconsin, 3epartr ent of Natural Resources, Technical Bulletin No.88,
Madison, W~ sconsin 1975.
Municipal SI idge M: oagement, Chapter NR 204, Bureau of Natural Resources,
Register, M: rch 19E >, No. 351, Madison, Wisconsin, 1985.
Interim Gui lelines or the Disposal of Liquid and Solid Waste Containing
Radium froi i Wisco -.sin Water Treatment Plants, Prepared by the State of
Wisconsin, E ureau o Solid Waste Management, Drafts of August and October
1988.
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B.7 METAL MINING AND PROCESSING WASTE
7.1 INTRODUCTION
The mining and processing of ores for the production of metals generates large
quantities of residual bulk solids and wastes. Because the minerals of value comprise only
a very small fraction of the ore, most of this bulk material has no direct use. It has been
estimated that the mining and processing of ores and minerals, other than uranium and
phosphate, has resulted in 41 billion metric tons (MT) of mine waste and tailings from 1910
to 1981 (EPA85). This industry typically generates about 1 billion MT of waste per year,
including waste rock and overburden, ore tailings, and smelter slag. The quantity of waste
materials and their physical and radiological characteristics differ widely among the various
metal mining and processing industries. In addition, depending on the processing methods
employed, some of the processing residues can contain elevated concentrations of
naturally-occurring radionuclides. Mineral residues stockpiled at any one site are not always
necessarily waste. Some tailings are in fact additional resources which may be subjected to
further processing to extract additional minerals. Smelter slag may be processed for the
extraction of additional minerals or it may be used as an additive in a variety of applications.
Because of the paucity of data, the waste generated by this sector is poorly understood.
The literature contains only a few studies on the metal mining industry and in most cases,
a few specific sites were evaluated for each type of metals. In addition, the characterization
of some of the metal mining industries was based on very limited field sampling and analysis
programs.
In July, 1990, the EPA published a document titled "Report to Congress Special
Wastes from Mineral Processing" (EPA90). This report provides information on waste
volumes, radionuclide concentrations, and commercial uses of processing wastes (slag and
leachate) from the smelting and refining of mineral ores to produce primary metals.
Information is included on wastes from the production of aluminum, copper, ferrous metals
(iron and steel), lead, titanium, and zinc. Only very limited data are provided on NORM
concentrations in these wastes. The EPA used screening criteria of 5 pCi/g of Ra-226 and
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10 pCi/g of U-238 or Th-232 to define radionuclide concentrations in waste or leachate
samples that could endanger human health.
Radionuclide concentrations in waste samples from the production of aluminum and
titanium are reported in EPA90 that exceed these criteria. In slag samples from processing
copper ores, Ra-226 concentrations are reported to be less than 5 pCi/g. No data on
radionuclide concentrations in waste samples from the production of ferrous metals, lead, or
zinc are given in the report.
It is generally believed by geologists that the presence of naturally-occurring
radioactivity is more dependent upon the geological formation or region than on a particular
type of mineral ore. It will also be apparent from reading the remainder of this section that
ores often contain many different minerals. Accordingly, it cannot be assumed that the
radionuclide content of one type of ore and its associated waste will be representative of a
metal industry.
There have been reports that some of the more uncommon metals have highly
radioactive waste products. Also, some of the processes associated with metal extraction
appear to concentrate radionuclides and enhance their environmental mobility. Some
published information and data to support these arguments have been presented, but in most
cases it is suggested that further studies be conducted prior to reaching any conclusions.
The processes associated with aluminum, copper, zinc, tin, titanium, zirconium,
, ferrous metals (iron and steel), and lead are discussed in this section. Elemental
phosphorous is described in Section B.2. The minerals and metals described in this section
were not really selected, but rather included because the availability of information and data.
Some of the other metals, such as gold and silver, may be found in copper ore, and may also
exist in other types of geological settings and at different abundances. No information was
available for ores processed primarily for gold, silver, or molybdenum. However, it is
generally recognized that pitchblende ore with high uranium content has been found in old
precious metal mines or mine waste. Therefore, it is not reasonable to dismiss these or any
other metal industries as being free of NORM waste based only from the available
information.
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In the sections that follow, an overview is provided of metal mining followed by a
discussion of a number of metal mining and processing industries. A description of the
properties of such mining waste and its potential to generate enhanced sources of
naturally-occurring radioactive materials is also presented. Estimates of the actual and
projected waste generation rates are also given for this NO£M sector. This information is
used to assess potential exposures to members of the general public and critical population
groups. A radiological risk assessment is performed (see Chapter D) assuming that the
exposed population is residing near a generic site.
7.2 OVERVIEW OF THE METAL MINING INDUSTRY
Mineral ores are mined by both surface and underground mining methods. In many
respects, the "lining methods characterizing the uranium mining industry also apply to metal
mining (see Section B.I for details). For the sake of simplicity and to avoid some redundancy,
the radiological characteristics of each metal mining segment are included in this Subsection.
Section 7.4 provides a summary and highlights the radiological data presented in the
following subsections.
7.2.1 Metal Mining and Waste Production
The bulk of residual material from metal Dining and processing is the soil or rock that
mining operations generate during the process of gaining access to an ore or mineral body.
This material includes the overburden from surface mines, underground mine development
rock, and other waste rock, including rock and ore. In 1986, the total solid material handled
at all surface and underground mines in the U.S. was 2,385 million metric tons (MT). Of this,
metal mines handled 989 million MT (DOI87). The mine piles cover areas ranging from 2 to
240 hectares, with an average area of 51 hectares. Some of this bulk material may be
considered waste, while other portions of it have economic value as low grade ore or for use
in other applications.
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After the ore is mined, it undergoes benefication where the crushed ores are
concentrated to free the valuable mineral and metal particles (termed values) from the matrix
of less valuable rock (called gangue). Benefidation processes also include physical and
chemical separation techniques such as gravity concentration, magnetic separation,
electrostatic separation, flotation, ion exchange, solvent extraction, electrowinning,
precipitation, and amalgamation. The choice of beneficiation process depends upon the
properties of the metal or mineral ore and the gangue, the properties of other minerals or
metals in the same ore, and the relative costs of alternative methods. Almost all processes
generate tailings, which may be considered waste material or may have economic value for
subsequent mineral extraction.
Tailings are the materials remaining after physical or chemical beneficiation removes
the valuable constituents from the ore. Tailings generally leave the mill as a slurry
consisting of 50 to 70 percent (by weight) liquid mill effluent and 30 to 50 percent solids (clay,
silt, and sand-sized particles). Significant quantities of slag and sand may also be generated
from some high temperature extraction processes.
More than half of the mill tailings are disposed in tailings ponds, which also serve as
the primary method to treat wastewater in the metal mining industry. Settling ponds are
also used at several mineral mining processing sites for the management of liquid waste.
Pond size and design vary by industry segment and mine location. Some copper tailings
ponds in the southwest cover 240 to 400 hectares (one exceeds 2,000 hectares), while some
small lead/zinc tailings ponds cover less than 1 hectare. Based on a Bureau of Mines survey
of 145 tailings ponds in the copper, lead, zinc, gold, and silver industries, the average size of
these ponds is approximately 200 hectares. Many facilities use several ponds in series to
improve the treatment process. Multiple-pond systems offer other advantages as well, as the
tailings themselves are often used to construct dams and dikes.
Technological advances have made it economically feasible to beneficiate ores taken
from lower-grade ore deposits (i.e., those with much higher waste-to-ore ratios). For example,
froth flotation beneficiation processes have had a significant impact on mine production and
upon waste generation. Not only have these advances increased mining production, but the
volume of waste generated also has risen dramatically. The tailings from froth flotation
operations are generally alkaline because the process is more efficient at higher pH levels.
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The metals in the alkaline tailings solids are believed to be immobile, unless chemical
conditions change over time.
Dump leaching, heap leaching and in situ leaching are other processes used to extract
metals from low-grade ore. In dump leaching, the material to be leached is placed directly on
the ground. Acid is applied, generally by spraying, although many sulfide ores will generate
acid during wetting. As the liquid percolates through the ore, it leaches out metals. The
leachate, "pregnant" with the valuable metals, is collected at the base of the pile and
subjected to further processing to recover the metal. Dump leach piles often cover hundreds
of hectares, rise to 60 meters or more, and contain tens of millions of metric tons of low-grade
ore, which becomes waste after leaching.
Bauxite and Aluminum
Bauxite is an ore containing hydrated aluminum oxide minerals, such as gibbsite,
boehmite, or diaspora and is formed by the weathering processes on aluminum bearing rocks.
Impurities in bauxite consist of Fe2O3, SiO2, and TiO2 (CRC81). Most bauxite is imported
from countries in Africa and South America and from Jamaica. In 1986, only 522 thousand
MT were mined in the United States while the amount used was 6,978 thousand MT
(DOI87). Two surface mines in Arkansas have been responsible for all recent bauxite mining
in the United States.
The only ore benefitiation operations performed at these mines include crushing and
grinding. Water used for dust suppression, mine dewatering, and surface runoff results in the
generation of a small volume of waste water. This water is neutralized by lime and discharged
into nearby streams (EPA78a).
Bauxite refineries produce alumina (A^O-j) which is used as a feedstock for the
aluminum reduction industry. By late 1989, five facilities in the United States were active
for domestic alumina production (EPA90). The locations and ore sources for these facilities
are shown in Table B.7-1. The total annual production capacity for the domestic bauxite
refining industry, as reported by these facilities, is approximately 4.9 million MT. The total
reported 1988 production of alumina was 4.086 million MT.
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Table B.7-1. Bauxite refineries.
(Source: EPA90)
Owner Location . Ore Source (1982)
ALCOA Bauxite, AR U.S. (Bauxite, AR)
ALCOA Point Comfort, TX Confidential
Kaiser Gramercy, LA Jamaica
ORMET Burnside, LA Sierra Leone, Brazil,
Guyana
Reynolds Gregory, TX Australia, Jamaica, Brazil,
Guinea
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Bauxite ore is processed at an alumina plant using the Bayer or a modified Bayer
process. Dried bauxite is mixed with a caustic liquor in slurry tanks, transferred to heated
digesters where additional caustic is added to dissolve the7alumina from the bauxite. The
liquor is then pumped through settling tanks to remove the bauxite residue. This spent
bauxite residue, called "red mud", is placed in a tailings impoundment near the plant. Red
mud in some plants is processed to remove sodium aluminum silicate in the form of pure
chemical grade alumina hydrates. The waste product is called "brown mud". Hydrated
aluminum oxide is precipitated from the liquor and heated in rotary kilns to drive off water
to produce aluminum oxide. The alumina can be further processed, transferred, or sold to
another facility.
The refinery muds contain significant amounts of iron, aluminum, calcium, and
sodium. They may also contain trace amounts of elements such as barium, boron, cadmium,
chromium, cobalt, gallium, lead, scandium, and vanadium, as well as radionuclides. The
types and concentrations of minerals present in the muds depend on the composition of the
ore and the operating conditions in the digesters. The material is caustic and no use has
been made of impounded muds. However, muds might be used for land reclamation, for the
construction of site dams or embankments, or as a feed material for other extraction
processes because of the iron content.
A study conducted by the EPA (EPA82a, EPA78a) indicates that the refinery process
generates about one ton of solid waste during the production of one ton of aluminum. This
includes a small amount of waste rock, the red and brown muds, and a small amount of scrap
and solid wastes coming from the smelter. The red and brown muds are precipitated from
a caustic suspension of sodium aluminate in a slurry and routed to large on-site surface
impoundments. In these impoundments, the muds settle to the bottom and the water is
removed, treated, and either discharged or reused. The muds dry to a solid of very fine
particle size (sometimes less than 1 um). In aggregate, the industry-wide generation of red
and brown muds by the five domestic bauxite refineries, shown in Table B.7-1, was
approximately 2.8 million MT in 1988 (EPA90).
The impoundments that receive the muds typically have surface areas between 44.6
and 105.3 hectares, although one impoundment is only 10.1 hectares and another is almost
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1,300 hectares. The depth of the impoundments range from 1 to 16 meters, with an average
impoundment depth of 7 meters. As of 1988, the quantity of muds accumulated onsite at the
five faciHties ranged from 500,000 to 22 million MT per facility, with an average of 9.7
million MT per facility.
In order to characterize the radiological properties of such wastes, the EPA conducted
a radiological evaluation of a mine and associated aluminum processing plant (EPA82a). The
selected site was a surface mine with several open pits ranging in size from 0.3 to 3 hectares.
The overburden and waste and rock were placed into previously mined pits. The bauxite ore
was found to be elevated in both U-238 and Th-232, with concentrations of 6.8 and 5.5 pCi/g.
The Ra-226 concentration was noted to be higher than that of U-238, at 7.4 pCi/g. Po-210 and
Pb-210 concentrations were higher still, at 10 and 9.1 pCi/g, respectively.
The concentrations of these radionuclides in red mud were noted to be about the same
as that of bauxite. In brown mud, the concentrations were notably lower, except for thorium
which was higher than either bauxite or red mud. Table B.7-2 presents radionuclide
concentrations measured in bauxite ore and alumina samples. Data on radionuclide
concentrations in refinery muds are also available from industry responses to a RCRA §3007
request in 1989 and from a 1985 sampling and analysis effort by EPA's Office of Solid Waste
(OSW) (EPA90). Data on three mud samples gave a median Ra-226 concentration of 14.1
pCi/1 and a median U-238 concentration of 8.75 pCi/1.
Radon-222 flux measurements were made using charcoal canister on ore bodies,
overburden materials, spoil areas, and in open pits. The measurement results indicated
varying radon surface flux rates, ranging from a low 2.6 to as high as 62 pCi/m2-s. The local
background radon flux rate was reported to be 0.38 pCi/m2-s. Table B.7-3 presents individual
and average radon flux rates for different locations at the mining site.
7.2.3 Copper
The copper industry is primarily located in the arid western United States. In 1986,
there were a total of 18 operating mines which moved a total of 468 million MT of ore
(DOI87). The amount of marketable copper is small compared with the material handled.
B-7-8
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Table B.7-2. Radionuclide concentrations in alumina plant process samples.
(EPA82a)
Radioactivity Concentrations (pCl/e)*
Sample
Bauxite
Ore
Blended
Bauxite
Alumina
Kiln
Feed
Alumina
Product
RC-64
Alumina
Red Mud
Filter
Cake
Prepared
Sinter
Mud
Sinter
Brown
Mudb
U-238
6.8*0.7
4.0*0.5
0.05*0.03
0.28*0.10
0.31*0.09
7.5*1.2
4.8*0.5
6.4*0.8
5.5*0.4
U-234
6.9*0.7
4.0*0.5
0.07*0.03
0.28*0.10
0.35*0.10
7.5*1.2
4.7*0.5
6.6*0.9
5.6*0.5
Th-230 Ra-226
6.4*1.1 7.4*2.2
3.5*0.3 4.4*1.3
<0.05 0.08*0.05
<1 0.23*0.07
<0.6 0.19*0.06
5.1*1.3 6.5*2.0
-
4.2*1.1 3.9*1.2
6.5*1.6 3.9*1.2
8.0*2.7 5.6*1.2
Pb-210 . Po-210
9.1*1.1 10.0*1
5.3*0.4 4.2*0.5
0.20*0.15 0.00*0.20
<1.4 <0.6
<1.3 <0.6
7.6*0.4 7.7*1.7
6.8*0.4 4.6*0.5
3.6*0.4 3.2*1.2
5.7*0.8 5.4*0.7
Th-232
5.5*1.0
5.2*1.2
<0.05
<0.2
<0.2
6.0*1.5
5.0*1.3
9.2*2.1
12.5*4
Th-228
5.5*1.0
5.6*1.2
<0.05
<0.2
<0.2
6.3*1.5
5.5*1.4
8.6*2.0
12.5*4
a Picocuries (10-12 curies) per gram plus or minus twice the standard deviation based on counting statistics.
b Hie results are derived Tram duplicate samples.
B-7-9
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Table B.7-3. Bauxite open-pit radon surface flux rates.8
Location Radon Surface Flux Rateb
Top of ore body 35
Top of ore body 62
Top of ore body 39
Average 45
Top of overburden - topsoil removed 5.9
Overburden sidewall, 5 ft. below top 13
Overburden sluffage berm, midway between 2.6
surface and top of ore
Average 7.2
Spoils area 4.9
Spoils area 12
Average 8.5
Pit background, undisturbed soil 27
Pit background, undisturbed soil 9.6
Pit background, undisturbed soil 16
Pit background, undisturbed soil 35
Average 22
a Data extracted from EPA82a.
b Units are in picocuries per square meter per second. There are 10"1Z curies in one
picocurie.
B-7-10
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Over 300 MT of ore must be handled for each metric ton of copper metal produced. Thus the
waste quantities are very large. Because of the large quantities of waste, the processing
facilities are usually located near the copper mines.
The vast quantities of ore, overburden, and rock are segregated, at the mine site
where the rock is hauled by truck to the rock dump. The ore is then crushed and mixed with
other low-grade ore and is chemically leached to remove the copper. The higher grade ore is
further milled and the end product is concentrated by physical separation, such as a flotation
process. The tailings are pumped to the tailings pile and the copper concentrate is
transported to a nearby smelter.
The locations of ten primary copper processing facilities that, as of September 1989,
were active in the smelting and refining of copper concentrate are shown in Table B.7-4.
During the early 1980s, production of copper in the U.S. declined as a result of a drop
in copper prices. However, primary production of copper in the U.S. increased throughout
the late 1980s. Between 1986 and 1989, production from domestic and imported raw
materials increased by 38 percent. Imports of refined copper for consumption decreased by
40 percent (from 502,000 MT to 300,000 MT), while exports increased 833 percent (from
12,000 MT to 100,000 MT) (EPA90). Most smelting and refining facilities have recently
undergone modernization. The total annual primary copper smelting production capacity
currently stands at about 1.27 million MT per year of anode copper; the primary copper
refining capacity is about 1.33 million MT per year of refined copper.
The demand for copper is closely tied to the overall economy, and demand remained
relatively flat through the late 1980s. Total apparent consumption of copper in the U.S. rose
slightly from 2.136 million MT in 1986 to 2.250 million MT in 1989. Future demand depends
upon the health of the economy. Almost 40 percent of the 1988 U.S. consumption of copper
went to the building and construction industries, while about 23 percent was used by the
electrical and electronic industries. Industrial machinery and equipment, the power
generation industry, and the transportation industry together consumed 38 percent of the
copper produced in the U.S. in 1988 (EPA90).
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Table B.7-4. Primary copper processing facilities.
(Source: EPA90)
Tvt»e of Operation
Owner
ASARCO
ASARCO
ASARCO
Kennecott
Copper Range
Cyprus
Magma
Phelps Dodge
Phelps Dodge
Phelps Dodge
Location
Amarillo, TX
El Paso, TX
Hayden, AZ
Garfield, in-
White Pine, MI
Claypool, AZ
San Manuel, AZ
El Paso, TX
Hurley, NM
Playas, NM
Smelter and
Converter
No
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Anode
Furnace
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Electrolytic
Refinery
Yes
No
No
Yes
Yes
Yes
Yes
Yes
No
No
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In 1986, there were 172 million MT of crude ore handled from copper mines in the
United States. In addition, 295 million MT of waste were processed for disposal. Only 5
percent of this material came from underground mines (DOI87). Note that this is significantly
less than the 723 million MT of waste handled at copper mines in 1980 (EPA85). For copper
mines (1980 data), approximately 33 percent of the waste i? tailings, 28 percent are dump
and heap leach wastes, and 39 percent is comprised of waste rock and overburden. This
distribution is believed to still represent current practices.
Tailings piles vary in size, but may be as large as 400 hectares for copper mines in the
southwest. The waste rock and leach piles may also reach 400 hectares each. A study of 12
tailings piles (EPA85) revealed that no tailings pile liners were used and only two sites were
reported to monitor ground water. Such data is misleading in that New Mexico, Arizona,
Colorado, and California require ground water monitoring since these states already have a
large number of existing mill tailings piles. Some of the copper mine wastes have been put
to use, but on a limited scale. Mixtures of crushed waste rock, including waste rock from the
copper mines, have been used to construct embankments, fills, or pavement bases for
highways. Some bench scale studies have shown that copper tailings can be used in bricks
if pyrites are first removed (EPA85).
The three steps in copper smelting consist of roasting, smelting, and converting. The
copper ore concentrates are roasted or heated in an oxidizing atmosphere which partially
drives off some of the sulfur as sulfur dioxide. Where roasters are not employed, the ore is
dried by heating in a rotary dryer if the concentrate has a high moisture content.
The smelting stage consists of using a smelting furnace to melt and react copper
concentrates and/or calcine in the presence of silica and limestone flux to form two immiscible
layers. One of the layers is waste consisting of iron and silica compounds, which'is discarded
on the slag pile. The other layer called "matte copper" consists of copper and iron sulfide and
other metals.
The matte copper is placed in a converter where silica flux is added, and the resultant
mixture is air blown to produce a copper rich slag, which is returned to the crusher. The
remaining molten mass is then air blown to convert the copper sulfide to blister copper which
is transferred to an anode furnace for casting.
B-7-13
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The typical copper concentrations were noted to range from 0.5 to 1.0 percent in
copper ores used by a smelter evaluated by the EPA (EPA78a, EPA78b). All ores with an
abundance of 0.3 percent or less are rejected as waste rock. Since the concentrate feed rate
to the smelter is approximately 3 times that of the copper production rate, in a reverberatory
furnace (smelter) slag is produced at a rate which is about 75 percent that of the incoming
copper concentrate. The EPA's report to Congress on special wastes from mineral processing
(EPA90) indicates that 2.5 million MT of smelter slag and 1.5 million MT of slag tailings
were generated by copper smelting and refining facilities in the U.S. in 1988. The slag waste
volume from copper smelting and refining is very small compared to the overburden and
tailings waste volumes from mining and beneficiation operations.
At the eight active copper smelters (Table B.7-4) smelter slag is initially deposited on
waste piles. These slag piles range in surface area from about 1 to 30 hectares, and in height
from 3 to 45 meters. Slag accumulations in individual piles ranged from 0.5 to 21 million MT
as of 1988.
Three smelters (San Manuel, White Pine, and Garfield) subsequently process all their
smelter slag either in a conventional ore concentrator or in a stand-alone slag concentrator.
The slag tailings from these operations are co-managed at on-site tailings piles with the
tailings from ore beneficiation. Slag tailings ponds range from 142 to 2,270 hectares with an
average size of about 600 hectares. Depths range from about 16 to 61 meters with an
average depth of 46 meters. As of 1988, quantities of slag tailings in these ponds ranged
from 240,000 MT to 3.4 million MT, with an average of 1.8 million MT.
Copper slag may be used as a source of secondary metals and in various applications
in road and building construction. Research has been conducted on removing secondary
metals such as iron, nickel, and cobalt from copper slag, but commercial facilities for metals
recovery are not currently in operation. Copper slag has been used as an aggregate in
asphalt and seal coats in highway construction in Arizona and Utah, which are among the
top generators of copper slag. It can be used as a source of aggregate in portland cement
concrete. It has also been used for road cindering, as granules for roof shingles, as pipe
bedding, and in road beds when mixed with a sufficient quantity of road rock. Copper slag
was used in construction of a large portion of the Southern Pacific railroad roadbed from New
Orleans to San Francisco.
B-7-14
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Several EPA studies have reported uranium and thorium concentrations in various
copper mining and processing materials. Unfortunately, the primary goals of these studies
were not to perform a radiological characterization, and thus very little relevant data were
obtained. The locations of the study sites were not identified, but it is known that one of the
sites was in the Southwest (Arizona or New Mexico). Table B.7-5 summarizes the results of
these studies. The EPA's report to Congress on special wastes from mineral processing
(EPA90) reported Ra-226 concentrations in samples of copper slag to be less than 5 pCi/g.
From t>"'g information, it might be concluded that radionuclide concentrations, copper
mining, and processing wastes are at about the natural crustal abundance. However, a review
of available information for the State of Arizona, where much of the copper is produced,
might lead to a different conclusion.
Uranium has been found in many primary metals deposits in Arizona where it is
associated with copper and molybdenum in large porphyry copper ore bodies and in vein
deposits with copper, lead, and zinc sulfides. Uranium is also known to occur in significant
quantities in oxide and sulfide ores. Table B.7-6 presents a summary of uranium bearing
metalliferous deposits in selected Arizona mining sites. The following discussion highlights
some of the important findings noted at these sites.
The presence of uranium has been documented at the Esperanza mine, located in the
southeastern Sierritas about 25 miles SSW of Tucson and 10 miles SW of the community of
Sahuarita. Assay results of stockpiled ore indicate that U3O8 is present at 0.11 to 0.18
percent (PEI70).
The Twin Buttes mine lies roughly four miles northeast of Esperanza and about 23
miles south of Tucson. At Esperanza, uranium, as uraninite and secondary uranium
minerals, has been found with molybdenite and copper minerals. Whether or not these are
from oxide ores originating from early open pit operations (as at Twin Buttes) or from sulfide
ores, perhaps from earlier underground mining, is uncertain. Twin Buttes and Esperanza are
only two of a number of fairly large open-pit porphyry copper-molybdenum producers found
on the east side of the Sierrita Mountains, southwest of Tucson. Other mines, Pima-Mission,
and San Xavier are in fact closer to Tucson, about 16 miles away. The absence of uranium
B-7-15
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Table B.7-5. Radionuclide concentrations in copper materials.
EPA82a
Material EPA-79
Ore:
Surface mine
waste:
Ore 0.7(0.8)
concentrates:
Tailings:
Furnace slag: 3(5)
Leach material:
EPA-83b
0.8-1.78
0.02-1.48
1.19-2.99
Underground
0.79(0.62)
0.65(0.07)
0.82(0.24)
Ooen Pit
2.2(3.1)
1.4(1.1)
1.6(3.0)
a The results are for U-238, those in parenthesis are for Th-232.
b For plants located in Arizona or New Mexico and at other unspecified locations.
B-7-16
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Table B.7-6. Selected uranium bearing metalliferous deposits In Arizona.
Name
TwinBuUes
Esperanza
Bisbee
Morend
Copper Sqaw
to
^ Black Dike
King Mine
Gierno group
Miscellaneous near
Patagonia
Hillside
Miscellaneous
Cerbat Mountain
mines
Location
E Sierrita Mounlaina.
SW of Tucson
SE Sierrita Mounlaina,
SW of Tucson
Bisbee, AZ
Morend, AZ
Quyoloa
Papago Indian
Reservation
NW Sierrita Mounlaina,
W of Tucson
Northern Santa Rita
Mountains. S of Tucson
at Helvrta
Las Guyaa Mountains
SW of Tucson. SW of
Twin BuUes, Esperanza
Southern Santa Rita
Mountains close, N of
Nogales
Near Bagdad (3 miles
north)
Cerbal Mountains N of
King man
Mining
District County
PimaDiaL
PimaCo.
PimaDiaL
PimaCo.
Warren Dist
CochiseCo
Copper Mountain
Greenlee Co.
Qujjoloa DisL
PimaCo.
Papago DiaL
PimaCo.
Helvina DiaL
PimaCo.
Las Guyaa DisL
PimaCo.
Wrightston DisL
Santa Cruz Co.
Eunka Dist.
Yavapai Co.
Cerbal Mohave
Principal
Commodlty(le)
Copper
Copper.
molybdenum
Copper
Copper
Copper
Prospect
Silver, copper
Gold-silver
Silver-base
metala (lead)
Cold, silver, line,
lead
Base and precious
metals
Type of Mine
Open pit porphyry
copper
Open pit porphyry
copper
Open pit
Open pit porphyry
Old property vein
Shaft with dumps
Van; underground
old workings area
drilled out for
porphyry copper
(Old mining area)
veins
U-second-ariea
associated with
Galena (PBS)
Underground van
Old mines, vans
Th Association
Uranium in aide ore
Uranium with copper
and molybdenum
mineralization
Uraninite in tones in
sulfide or bodies,
hematite, quartz
Scattered uranium
mineralization
associated with copper
Uranium associated
with oxidized copper
andiron
PiUhblend with
MnOx. Cu Sulndes
and fluonte
PiUhblend with Fe
and Cu sulftdea
Uranium minerals
associated with copper
and iron
Uraninite and old
lead-silver and silver
base metal workings-
veins
Uranium secondary
minerals found on
dria walls.
PiUhblend also
reported with gold,
silver, base metals,
and (luonte
Uranium minerals
with quartz and base
metal sulfides
Assaya Reported
Unknown; produced
yellow cake 1980-1986
0.111-0.182%
eU,0,-old ore
Not given
Not given
0.76-1.4%
0.01 1-0. 16 to U
(»U,0.)
0.14-0.934
*A
0.124.30%
"A
0.024.07%
eU,0. with an assay of
2.3%
0.014.6%
Ref.
(Pdrce 70)
(Beard 89)
(Beard 89)
(Beard 89)
(Beard 89)
(McDonnd 89)
(Beard 89)
(Peiree 70)
(Beard 89)
(Peiree 70)
(USCS 63)
(Peiree 70)
(Peiree 70)
-------
at these mines does not preclude its presence as the geology and mineralogy is fairly similar
(BEA89).
Uranium is found in various base metal deposits in a band extending at least 10 miles
northwest from Twin Buttes and Esperanza, cutting across the Sierrita Mountains. This band
tentatively ends at the now non-producing Black Dike Mine located on the northwest side of
the Sierrita Mountains, some 27 miles SW of Tucson. At this site, uranium in abundance as
high as 0.16 percent has been found in a contact zone of U3O8 exposed by a shaft associated
with copper minerals and fluorite mining (PEI70). On the surface, dumps with copper oxides,
sulfides, and purple fluorite have been observed with anomalous radioactivity levels
(MCD89).
At the much smaller nearby Black Dike mine, uranium has been found in varying
amounts with sulfide base metals, mainly in vein like deposits (PEI70).
Elevated levels of uranium have also been observed in the Tucson region, outside of
the Sierritas. The King mine, an old silver and copper mine, is one of several in the area
where pitchblende occurs (with sulfides) with assay results ranging from 0.14 to 0.93 percent
U3O8 (PEI70). The mine is located on a contact zone exposed by underground mine workings.
It appears that this mine is one of several which have been developed under recent
exploration efforts (BEA89).
Other Arizona uriniferous-metallic occurrences are known to exist in or near other
large copper mines in Arizona. Uranium is present in sulfide ore bodies at Bisbee, where it
is associated with quartz and hematite (PEI70, USG63) and is found in trace amounts
scattered along with copper mineralization at Morenci (PEI70). No assay results were given
in any of the reviewed literature. The Morenci mine is a large open-pit porphyry copper mine
located in the eastern part of the state, northeast of Safford. Bisbee is also an open-pit copper
mine, located near the Mexican border, between Douglas, Sierra Vista, and Tombstone.
Uranium is found in trace amounts, at an average of 0.0055 percent U308, in porphyry
copper deposits in the Miami district, east of Phoenix (STI62). Uranium has also been found
in copper sulfide in schist veins near Globe (MCD89). It is not known if such deposits exist
B-7-18
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at the San Manuel, Ray, and Christmas mines, which are widely dispersed between the north
side of the Santa Catalina Mountains north of Tucson and the Dripping Springs Mountain.
Uranium occurs in the Bagdad District, some 35 miles west of Prescott, with U3O8
concentrations being as high as 2.3 percent in the Hillside mine (USG55). The Hillside mine
is an old mine (gold - silver - zinc - lead) located on a fissure vein. The abundance of uranium
at this location is probably much less, perhaps closer to 0.1 percent U3O8 (PEI70).
The data on uranium occurrences in metalliferous deposits in Arizona, summarized
in Table B.7-6, probably reflects a biased sampling program. Still (STI62) has reported
results for 441 ore samples taken in the Miami district of Arizona for which he cited U308
concentrations as high as 0.018 percent, with a mean of 0.016 percent. While it is possible
to find copper mining wastes with uranium concentrations that are typical of pitchblende, it
is probable that large site averages are much less, being probably closer to 0.01 percent. This
corresponds to U-238 concentrations in the waste of about 34 pCi/g.
Based on this review, it is difficult to characterize the radiological properties of
overburden and tailings associated with the mining and processing of copper ores. The data
presented above do not indicate that radionuclides are concentrated in any of the waste
streams. However, elevated exposures may be associated with the use of materials from
waste rock piles, leach piles, furnace slag piles, and tailings piles. A more detailed survey
of wastes and tailings, especially from the copper mines and mills of Arizona and New mexico
is warranted to better characterize these potential NORM wastes.
7.2.4 Zinc
In 1987, approximately 50 percent of the production of zinc ore was from Tennessee,
with New York, Missouri, and 8 other states sharing the balance (DOI87). The 1987 ore
production was 216,981 MT (DOI89). In 1989, U.S. production of mined zinc rose to 300,000
MT (EPA 90). By 1991, U.S. mine production of zinc could double that of 1989, due primarily
to the large Red Dog, Alaska mine, which opened in November 1989 (BOM90). A major
factor leading to the increased production of mined zinc has been the strong demand from the
B-7-19
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automobile industry for galvanized sheet metal. Galv. nizing accounted for 45 percent of zinc
consumption in 1989.
Zinc processing facilities in the U.S. include OE i at Monaca, Pennsylvania which uses
pyrometallurgical (smelting) techniques and three ac ditional facilities that use electrolytic
production techniques. In 1988, the Monaca facility p oduced 99,800 MT of zinc and 157,000
MT of zinc slag.
At the Monaca facility, the furnace slag is or .bed and separated into four material
streams: zinc fines, reclaimed coke, processed slag, a .d ferrosilicon. The fines and coke are
recycled to benefication and processing operations a . the facility. The processed slag and
ferrosilicon are placed on slag piles. The processed slag pile covers an area of about 1.2
hectares and is roughly 7 m in height The ferrosilict i pile has a basal area of 8,000 square
meters and is also about 7 m high. In addition, slag h is been placed in a layer at the bottom
of the facility's flyash landfill that is approximately ( 3 m deep and covers an area of about
8 hectares. As of 1988, quantities of waste accumul .ted in the ferrosilicon pile, processed
slag pile, and the landfill were about 48,000, 63,500, and 45,400 MT, respectively.
Slag at the Monaca facility has been used as ravel on parking lots and other areas
of the plant site. It has also been used as railroad b Hast, as an aggregate in asphalt, and
as an anti-skid material.
The EPA has conducted a characterization stuc / of a large underground zinc mine and
mill (EPA82b). The study revealed that the presenc. of U-238 and Th-232 and their decay
products were found in ores, concentrates, and tailing at less than 20 percent of the average
crustal abundances. The EPA's report to Congress on perial wastes from mineral processing
does not include any information on U-238, Th-232, o. Ra-226 concentrations in zinc smelter
slag. Since concentrations of these nuclides were to )e included in measurements made to
characterize mineral processing wastes, it may be concluded that any measured
concentrations were below the EPA's screening criter a (10 pCi/g for U-238 and Th-232, and
5 pCi/g for Ra-226). It would, therefore, appear tha the overburden, subore, tailings, and
smelter slag associated with the zinc mining and p ocessing industry do not represent a
B-7-20
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significant source of NORM wastes. Considering their use as construction materials further
radiological characterizations of zinc mining and processing wastes may be warranted.
7.2.5 Tin
Competitive pressures and a world wide excess in tin inventory have caused many
mine closures in recent years. Only one U.S. mine, located in Alaska, produced ore
concentrates in 1986, but no specific production data were available. However, this mine is
reported to produce only a small fraction of the total U.S. consumption (DOI87). The other
domestic tin producer is Tex Tin Corp., located in Texas City, Texas. This facility processed
domestic and imported ores, primarily from Peru. In 1987, the U.S. imported 2,953 MT of
concentrates. Total smelter production has been reported to be 3,905 MT (DOI87).
Amang is a general term for the by-products obtained when tin tailings are processed
into concentrated ores. It includes minerals, such as monazite, zircon, ilmenite, rutile, and
garnet Hu reported analytical results for among coming from Malaysia, including monazite,
xenotime, zircon, and thorium cake (HU85). While it is not known how the levels of
radioactivity in amang compares with titanium concentrates, Ra-226 and Th-232 activities
in amang were reported to range from 430-480 pCi/g and 1,160-8,830 pCi/g, respectively.
Accordingly, tailings from these ores appear to have a significant potential to cause elevated
radiation exposures, if used indiscriminately.
Gamma survey measurements made at the Tex Tin smelter revealed uncorrected
radiation levels in slag storage areas ranging from 10 uR/h to 500 uR/h, with average levels
of less than 60 uR/h. Four samples taken from such areas revealed U-238 concentrations up
to 43 pCi/g and Th-232 concentrations up to 19 pCi/g (CRC81). The State of Texas has
conducted some measurements at the Texas City Site (GRA89). Two slag pile samples, taken
in August of 1988, showed Ra-226 concentrations of 7.3 and 55 pCi/g. Uranium concentrations
were noted to be 17 and 34 pCi/g, while those for Ac-228 (Th-232 series) were found to be
lower at 2.9 and 7 pCi/g. No information was available regarding past uses or possible
applications of the slag from this tin smelter. No information on tin slag is given in the
EPA's report to Congress on mineral processing wastes.
B-7-21
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7.2.6 Til
U.S. titanium ore and concentrate supplies are obtained primarily from Australia,
South Africa, and Canada. The concentrates are produced from rutile (Ti02), leucoxene
(TiOj), and ilxnenite (FeTi03), as well as from titanium slag. Titanium is also found with iron
ore (titaniferous) which is imported from Canada. Titanium ore and concentrates are
processed by chlorination in a fluidized-bed reactor in the presence of coke to produce
titanium tetrachloride which is used as a feedstock to two major processes, production of
titanium dioxide and titanium sponge. Titanium dioxide is used primarily as a pigment in
the paper and paint industries; titanium sponge is used primarily in aircraft engines and
airframes. Nine facilities, located across the U.S., that were active in 1989 in the production
of titanium tetrachloride are shown in Table B.7-7.
The production and consumption of titanium metal in the U.S. has generally been
increasing because of its demand in the aerospace industry, mainly aircraft engines and
airframes manufacturing. While aerospace applications make up 78 percent of the use of this
metal, other applications are common where high-strength toughness, heat resistance, and
high structural integrity are needed. The use of titanium in automotive engines is being
considered. The consumption of TiO2, e.g., as a paint pigment, is also increasing. In general,
the demand is greater than existing world supplies (DOI87). Titanium metal production in
the U.S. increased by 12 percent, from 21,000 MT to 24,000 MT, between 1985 and 1989
(EPA 90). Titanium oxide pigment production increased by 8 percent, from 927,000 MT to
1.007 million MT, during this same period.
The chlorination of tit-**"""" ores and concentrates to produce titanium tetrachloride
produces chloride process waste solids. These solids are typically generated in a slurry with
waste acids. The solids in the slurry are particles with a diameter less than 0.02 mm
(smaller than sand). The aggregate industry-wide generation of chloride process waste solids
was 414,000 MTin 1988. Waste solids are managed in surface impoundments and/or settling
ponds. The waste solids piles are typically small, covering 0.5 to 5 hectares, and are about
1 to 10 meters in height. Recycling of waste solids to recover additional titanium and other
metals such as columbium, tantalum, and zirconium is the primary management alternative
to the current practice of neutralization and surface impoundment/landfill disposal. While
laboratory tests have demonstrated the technical feasibility of recycling, no full-scale
B-7-22
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Table B.7-7. Domestic titanium tetrachloride producers.
(Source: EPA90)
Owner
Location
Ore Type
E.I. duPont
E.I. duPont
E.I. duPont
E.I. duPont
Kemira
Kerr-McGee
SCM
SCM
TIMET
Antioch, CA
Edgemoore, DE
New Johnsonville, TN
Pass Christian, MS
Savannah, GA
Hamilton, MS
Ashtabula, OH
Baltimore, MD
Henderson, NV
Rutile
Ilmenite
Ilmenite
Ilmenite
Rutile
Synthetic Rutile
Rutile, S. African Slag
Rutile, S. African Slag
Rutile
B-7-23
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applications are known to exist. No other uses of titanium waste solids are reported in the
EPA's report to Congress on mineral processing wastes.
Much of the ore from which titanium is obtained originates in beach and fluviatile
sands which also contain monazite. Impurities in monazite are present at high
*
concentrations, and include uranium and thorium and their decay products. The
concentration of these radionuclides is expected to vary from ore to ore (CRC81). Data
gathered by the EPA indicate that in rutile and leucoxene ores, uranium and thorium were
present at concentrations in the range of 5 to 20 pCi/g (CRC81). Radium in sludge from
titanium-chlorination process streams was observed in concentrations as high as 77 pCi/g.
Radionuclides in liquid waste streams were found to be similarly elevated.
Analyses of 12 samples of chloride process solid waste from one titanium tetrachloride
producer showed a median Ra-226 concentration of 8.0 pCi/g with a range of 3.9 to 24.5 pCi/g
(EPA 90). The median U-238 concentration for these 12 samples was 1.5 pCi/g with a range
of 0.07 to 42.7 pCi/g. The median Th-232 concentration was 1.1 pCi/g with a range of 0.12
to 88.9 pCi/g.
7.2.7 Zirconium and Hafnium
The ores containing zirconium and hafnium are obtained as a by-product of mining
and extracting titanium minerals, ilmenite and rutile. Zirconium and hafnium are found in
mineral ore, zircon, in a ratio of 50 to 1. While hafnium is used to manufacture nuclear
reactor fuel control rods, it has few other uses and the demand is relatively small. Zirconium,
in the form of zircon, however, is widely used in foundry sands, refractory paints, and in
other refractory materials. World resources are large when compared to current demands.
The ores are primarily produced in Australia and the Republic of South Africa, which
presently have over 40 percent of the worlds' zirconium mining capacity (DOI85). In 1984,
there were 39 locations in the U.S. where zirconium materials were produced, primarily in
the East. Zircon or zircon ores were processed in Cleveland, Ohio; Wilmington, Delaware; and
Green Cove Springs, Florida. Zircon mineral concentrates are produced in Florida by E.I.
duPont de Nemours & Co., and Associated Minerals Consolidated Inc.
B-7-24
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Zirconium oxide is produced directly from zircon by either plasma fusion or electric
arc techniques. For the electric arc technique, a clinker is eventually formed which
disintegrates into a powder. The powder is air classified, and the zirconate crystals are
treated with acids or other reagents to form oxides and salts. The plasma method heats the
finely divided zircon concentrate above its dissociation temperatures, forming zirconia
crystallites and glassy amorphous silica. The hot zirconium oxide is quenched rapidly and the
glassy silica is leached out with sodium hydroxide solution, leaving the insoluble zirconia
crystallites. There are several other more complex processes for producing this metal,
however, such methods are costly and are not widely used.
Zircon and monazite are non-conductive and are separated from the titanium ores
electrostatically. Monazite, which is slightly magnetic, can then be separated from zircon by
electromagnets. Uranium and thorium are known to occur in high concentrations in monazite.
The separation of U-238 and Th-232 from zircon (and monazite) has not always been
accomplished successfully. An instance was cited (DOI85) in which mineral wastes on the
property of a U.S. producer of zirconium metal contained more Ra-226 than could be legally
allowed under state laws.
In recent years, zircon sands have been chlorinated directly in a fluidized bed
containing carbon. This converts the zirconium content of zircon to tetrachloride. A potential
source of significant amounts of NORM waste are believed to occur during the conversion
process of baddelezite (ZrO2) concentrates originating from the Republic of South Africa
(CRC87). The baddelezite concentrate (97 percent ZrO2) is a co-product of copper, phosphate,
and iron operations. The material is fused in an electric furnace, then crushed, ground, and
classified. This product is applied as a thermal coating on refractory products. Measurements
reported by Hendricks indicate that Ra-226 concentrations in ore were approximately 200
pCi/g, while the product itself (as a fine powder) was much higher, at 1,900 pGi/g (CRC87).
Hendricks pointed out that the direct chlorination of zircon puts the radium in the highly
soluble radium chloride chemical form, which yields very high leachate concentrations in
liquid waste streams (CRC87). In one plant, with radium ore concentrations at 100 pCi/g, the
Ra-226 concentration in water under the chlorinator residue pile were noted to be 45,000
pCi/L. The high solubility and mobility of radium chloride presents an potential threat to the
environment.
B-7-25
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As with the other metals, there is insufficient information with which to reach any
conclusions about typical NORM concentrations, other than knowing that this segment does
sometimes produce wastes with elevated levels of naturally-occurring radioactivity. Additional
investigations are required in order to better characterize this segment of the metal mining
and processing industry. No information on zirconium processing waste is contained in the
EPA's report to Congress on mineral processing wastes.
7.2.8 Ferrous Metals (Iron and Carbon Steel)
Iron blast furnaces use benefitiated iron ore to produce molten iron that can be cast
into products, but is primarily used as the mineral feedstock for steel production. Steel
furnaces produce a molten steel that can be cast, forged, rolled, or alloyed in the production
of a variety of materials. On a tonnage basis, about nine-tenths of the metal consumed in
the U.S. is iron or steel. Iron and steel are used in the manufacture of transportation
vehicles, machinery, pipes and tanks, cans and containers, and the construction of buildings,
roadway superstructures, and bridges.
Iron and steel are produced at 28 active ferrous metal facilities located in 10 states
throughout the U.S. Twenty-one of these facilities are located in five states (Ohio,
Pennsylvania, Indiana, Illinois, and Michigan) that are situated around the Great Lakes,
with access to lake transport of beneficiated iron ore. The locations and types of operations
at these facilities are shown in Table B.7-8. At 26 facilities, both iron and steel are produced.
One facility makes only iron and one makes only steel.
Iron is produced either by blast furnaces or by one of several direct reduction
processes; blast furnaces, however, account for over 98 percent of total domestic iron
production. The modern blast furnace consists of a refractory-lined steel shaft in which a
charge is continuously added to the top through a gas seal. The charge consists primarily
of iron ore, sinter, or pellets; coke; and limestone or dolomite. Iron and steel scrap may be
added in small amounts. Near the bottom of the furnace, preheated air is blown in. The
coke is combusted to produce carbon monoxide, the iron ore is reduced to iron by the carbon
monoxide, and the silica and alumina in the ore and coke ash is fluxed with limestone to form
a slag that absorbs much of the sulfur from the charge. Molten iron and slag are
B-7-26
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Table B.7-8. Domestic iron and steel producers.
(Source: EPA90)
Owner
Acme
Allegheny
Armco
Armco
Bethlehem Steel
Bethlehem Steel
Bethlehem Steel
Geneva
Gulf States Steel
Inland Steel
LTV
LTV
LTV
McLouth Steel
National Steel
National Steel
Rouge Steel
Sharon Steel
Shenango
US Steel
US Steel
US Steel
US Steel
US Steel
Warren Steel
Weirton Steel
Wheeling-Pittsburgh Steel
Wheeling-Pittsburgh Steel
Location
Riverdale, IL
Brackenridge, PA
Ashland, KY
Middletown, OH
Bethlehem, PA
Burns Harbor, IN
Sparrows Point, MD
Orem, UT
Gadsden, AL
E. Chicago, IN
E. Cleveland, OH
Indiana Harbor, IN
W. Cleveland, OH
Trenton, MI
Escore, MI
Granite City, IL
Dearborn, MI
Farrell, PA
Pittsburgh, PA
Braddock, PA
Gary, IN
Fairfield, AL
Fairland Hills, PA
Lorain, OH
Warren, OH
Weirton, WV
Mingo Junction, OH
SteubenviUe, OH
Type of Operation
Iron; BOF Steela
BOF Steel
Iron, BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron, BOF, OHF Steelb
Iron; OHF Steel
Iron, BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron, BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron
Iron; BOF Steel
Iron; BOF Steel
Iron, BOF Steel
Iron, OHF Steel
Iron; BOF Steel
Iron, BOF Steel
Iron; BOF Steel
Iron; BOF Steel
Iron; BOF Steel
a BOF: Basic Oxygen Furnace
b OHF: Open Hearth Furnace
B-7-27
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intermittently tapped from the hearth at the bottom. The slag is drawn off and processed.
The product, pig iron, is removed, cooled, and transported to steel mills.
All contemporary steelmaking processes convert pig iron, scrap, or direct-reduced iron,
or mixtures of these, into steel by a refining process that lowers the carbon and silicon
content and removes impurities (mainly phosphorus and sulfur). Three major processes are
used for making steel, based on different furnace types: the open hearth furnace (OHF),
accounting for 2 to 4 percent of total domestic steel production; the basic oxygen furnace
(EOF), with 56 to 59 percent of the total; and the electric arc furnace (EAF) accounting for
the remainder. The latter predominantly uses scrap (i.e., non-mineral material) as feed and,
therefore, does not contribute to the wastes of interest in this NORM assessment. The open
hearth process was prevalent in the U.S. between 1908 and 1969, but its use has diminished.
The basic oxygen process has supplanted it as the predominant primary steel-making process.
During the open hearth process, a relatively shallow bath of metal is heated by a
flame that passes over the bath from the burners at one end of the furnace while the hot
gases resulting from combustion are pulled out the other end. The heat from the exhaust gas
is retained in the exhaust system's brick liners. Periodically the direction of the flame is
reversed, and air is drawn through what had been the exhaust system; the hot checker-bricks
preheat the air before it is used in the combustion in the furnace. Impurities are oxidized
during the process and fluxes form a slag which is drawn off and processed or discarded.
The basic oxygen process uses a jet of pure oxygen that is injected into the molten
metal by a lance of regulated height in a basic refractory-lined converter. Excess carbon,
silicon, and other reactive elements are oxidized during the controlled blows, and fluxes are
added to form a slag. This slag is drawn off and processed or discarded.
In all of the iron and steel making operations, as at other smelters, gases from the
furnace must be cleaned in order to meet air pollution control requirements. Facilities may
use dry collection or wet scrubbers or, as is most often practiced, both types of controls.
Large volumes of dust and scrubber sludge are collected and processed or disposed.
Overall primary production of pig iron was steady throughout the latter part of the
1980s, while production of raw steel experienced a steady increase. Between 1985 and 1989,
B-7-28
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primary production of pig iron averaged 46 million MT. Production of pig iron in 1989 was
49.1 million MT (68.1 percent of production capacity) (EPA90). Production of raw steel
increased from 74 million MT in 1985 to 91 million MT in 1989. The estimated 1988 average
capacity utilization rate was 69.5 percent for the basic oxygen furnace and 45.3 percent for
the open hearth furnace.
Quantities of slag and air pollution control (APC) dust/sludge generated in 1988 by
the 28 facilities listed in Table B.7-8 are summarized in Table B.7-9. The total quantity of
slag and APC dust/sludge waste generated by these facilities during 1988 was 34.6 million
MT (EPA90). Waste management practices for iron and steel slag include recycling,
processing (e.g., crushing and sizing) followed by sale for use as aggregate, and disposal
on-site. Waste management practices for APC dust/sludge include disposal on-site and return
of the material to the production process via the sinter plant operation.
As shown in Table B.7-9, in 1988 nearly 18.8 million MT of iron blast furnace slag was
generated by the processing facilities listed in Table B.7-8. Approximately 14.4 million MT
of slag was sold for use in other applications. Distribution of air cooled iron blast furnace
slag among its various applications is shown in Table B.7-10. The remaining slag was stored
on-site. As of 1988, on-site accumulation of iron blast furnace slag at iron producing facilities
totaled over 14.6 million MT, ranging from none to 10 million MT at the different facilities.
The facility which has accumulated 10 million MT of slag, Inland Steel in East Chicago, is
placing it in Lake Michigan to create land on which additional waste can be deposited.
As shown in Table B.7-9, in 1988 over 13.2 million MT of steel furnace slag was
generated by the steel producing facilities listed in Table B.7-8. In 1988, U.S. steel mills
recycled approximately 1.8 million MT of steel slag. Over 5.1 million MT was sold for other
uses. The remaining 6.3 million MT of steel furnace slag was presumably stockpiled at either
the generating facilities or at the slag processing facilities. The distribution of steel furnace
slag among its various applications in 1988 is shown in Table B.7-11.
No data on radionuclide concentrations in wastes from ferrous metals production
facilities are given in the EPA's report on wastes from mineral processing (EPA90). Using
available data on the compositions of slag and APC dust generated during iron and steel
production, the EPA determined that concentrations of Ra-226, U-238, and Th-232 in these
B-7-29
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Table B 7-9. Special wastes generated by ferrous metals facilities in 1988.
(Source: EPA90)
Waste Types Amount (million MT)
Iron >last furnace slag 18.8
Iron >last furnace AFC dust/sludge* 1.2
Stee furnace slag 13.2
Stee furnace AFC dust/sludgea 1-4
a APC: air oollution control.
B-7-30
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Table B.7-10. Distribution of air-cooled iron blast furnace slag
among its various applications in 1988.
(Source: EPA90)
Application Distribution
Road base 57%
Concrete aggregate 12%
Pill 10%
Asphaltic concrete aggregate 7%
Railroad ballast, mineral wool, concrete products, glass 14%
manufacture, sewage treatment, roofing, and soil conditioning
B-7-31
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Table B.7-11. Distribution of steel furnace slag among its various
applications in 1988.
(Source: EPA90)
Application Distribution
Road base 46%
Fill 25%
Asphaltic concrete aggregate 11%
Railroad ballast, ice control, and soil conditioning 18%
B-7-32
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wastes are below screening criteria (5 pCi/g for Ra-226, and 10 pCi/g for U-238 and Th-232).
Hence no tests of radionuclide concentrations in iron and steel production wastes are reported
in EPA90. Ferrous metals wastes, including mine wastes, tailings, and processing waste
constitute the second largest quantity of metal mining and processing wastes (behind wastes
from copper production) generated in the U.S. Available information, based on analyses of
the chemical compositions of iron ores, indicates that NORM concentrations in these wastes
may be very small. However, because precise quantitative information on NORM
concentrations in these wastes is lacking, additional investigations are required to better
characterize this segment of the metal mining and processing industry.
7.2.9 Lead
Refined lead is produced from ore that comes from mines in Alaska, Idaho, Montana,
and Missouri. Processing of this ore is performed at five facilities shown in Table B.7-12.
The primary domestic use of lead is in lead-acid storage batteries. Lead is also used
in containers and as an additive for gasoline, although these uses are rapidly declining. Lead
is also used to manufacture lead oxides which are used in the battery, ceramics, rubber, and
coatings industries. The U.S. Bureau of Mines estimated that after a sharp decline between
1985 and 1986, the quantity of refined lead produced in the U.S. has slowly increased from
370,000 MT in 1986 to 395,000 MT in 1989. The Bureau estimates that primary smelter
production will remain at about 400,000 MT in 1990 (EPA90).
Primary lead processing consists of both smelting (blast furnace and dross furnace
operations) and refining. In the smelting process sintered ore concentrate is introduced into
a blast furnace along with coke, limestone, and other fluxing materials. The lead is reduced,
and the resulting molten material separates into four layers: lead bullion (98 wt. percent
lead); "speiss" and "matte", two distinct layers of material that contain recoverable
concentrations of copper, zinc, and other metals; and blast furnace slag. The lead bullion is
then drossed (i.e., agitated in a dressing kettle and cooled to just above its freezing point) to
remove lead and other metal oxides which solidify and float on the molten lead bullion. The
speiss and matte are sold to copper smelters for the recovery of copper and precious metals.
The blast furnace slag is stored in piles and partially recycled or disposed.
B-7-33
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Table 1.7-12. Primary lead processing facilities in the U.S.
(Source: EPA90)
Operate -/Owner Location Type of Operation
ASARCO East Helena, MT Smelter
ASARCO Glover, MO Smelter and Refinery
ASARCO Omaha, NE Refinery
Doe Run/Fluo Corp. Boss, MO Smelter and Refinery
DoeRun/Fluo Corp. Herculaneum, MO Smelter and Refinery
B-7-34
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Lead refining operations continue the process of removing various saleable metals
from the lead bullion. In the final refining step the bullion is mixed with fluxes to remove
remaining calcium, magnesium, and oxide impurities. Reagents such as caustic soda or
nitrates may be added to the molten bullion, which is then cooled, causing the impurities to
rise to the surface for removal. This refinery residue is returned directly to the blast furnace
at the Missouri facilities which involve integrated smelter/refinery operations. The refinery
slag at the Nebraska facility is discarded as solid waste. The EPA estimates the long-term
annual waste generation rate to be about 469,000 MT per year from lead processing (EPA90).
The predominant waste management practice at the five lead facilities is to return a majority
of the furnace slag to the sinter plant and stockpile the remainder. The total volume of slag
accumulated on-site at the four lead smelting facilities is approximately 2.7 million MT, with
quantities ranging from 430,000 MT to 1.36 million MT at the four smelters. The Omaha
refinery sends its slag off-site to a landfill.
The slag piles at the four smelting facilities range in area from 20,200 square meters
to 48,500 square meters and in height from 6 to 18 meters. The average dimensions of the
slag piles are 30,300 square meters and 10.5 meters high.
Lead slag has been used as an aggregate in asphalt to resurface roads. The slag has
been shown to have desirable anti-skid and wear resistant properties. It was used as an
asphalt aggregate in eastern Missouri for a number of years in the 1970s. The Missouri
State Highway Commission also made limited use of lead slag in asphalt mixtures to patch
and seal roads in the winter. In Idaho, granulated lead slag was used as an aggregate in
asphalt to pave Interstate Route 90. The EPA, however, has found no information indicating
that lead slag is currently used as an aggregate in asphalt road paving (EPA90).
Several other potential uses of lead slag are described in the EPA's report on special
wastes from mineral processing. It has been shown that finely ground lead slag can be used
to replace up to 25 percent of the Portland cement in steam cured blocks without significant
loss in block strength. In Idaho, granulated slag from the Bunker Hill smelter in Kellogg,
Idaho (now closed) was used as a frost barrier under slabs of concrete and asphalt, as well
as bedding material for buried pipelines. Lead slag has been used as an air-blasting
B-7-35
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abrasive. Valley Materials Corporation in Midvale, Utah is proce jsing (sizing) lead slag for
use as a railroad ballast.
No information on radionuclide concentrations in lead slagi; given in the EPA's report
on special wastes from mineral processing.
7.3 MINERAL PROCESSING WASTE GENERATION
7.3.1 Mineral Processing Waste Production
The total solid material handled at all surface and underg ound mines in the U.S. in
1986 was 2,385 million metric tons (MT). Of this, metal mines handled 989 million MT
(DOI87). Table B.7-13 presents the approximate distribution o this solid bulk material
reported for 1980. The distribution shown in Table B.7-13 is believ- d also to be representative
of current mining wastes generation practices.
A review of the volumes of mine waste and tailings genera ion reveals that almost 90
percent of the bulk material is from copper and iron ore. The i intipal mining states for
copper and iron are Arizona and Minnesota, respectively. Sine waste management and
disposal are performed locally, the majority of the wastes and otb r bulk materials from the
metal mining and processing industry remain at the point of gener ition. However, depending
on the mineral, a significant portion of the residual material .e., the raw ore) may be
shipped for further processing or use at other locations, typically away from the mines.
Estimated slag volumes generated in 1988 from smeltin; and refining raw ores to
produce primary metals are shown in Table B.7-14, summari ed from the information
presented previously in this chapter. The total slag volume is a out a factor of 20 smaller
than the volume of mine wastes and tailings shown in Table 1 .7-13. Slag from ferrous
metals production represents about 80 percent of the total slag vo ame produced by smelting
and refining raw ores, and copper slag represents almost 10 pen mt of the total.
B-7-36
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Table B.7-13.
Estimated amount of waste generated by the
mining and beneficiation of metal ores in 1980.a
Quantity of Waste (million MT)
Mining Sector
Copper
Gold
Iron Ore
Lead
Molybdenum
Silver
Zinc
Other metals
Total:
Mine Wastes
282
25
200
1
15
10
1
24
558
Tailings
241
10
150
10
31
3
5
5
455
Total
523
35
350
11
46
13
6
29
1,013
a Data extracted from EPA85, Table 2-10.
b Includes antimony, bauxite, beryllium, magniferous ore, mercury, platinum, rare earths,
tin, tungsten, and vanadium.
B-7-37
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Table B.7-14.
Estimated slag volumes generated du ing 1988
from processing raw ores to produce primary
metals.*
Copper
Zinc
Titanium
Ferrous Metals
Lead
Other Metalsb
Total
Slag Volume (million M
2.8
4.0
0.2
0.4
34.6
0.5
1.0
43.5
a Summarized from information presented in this chapter.
b Estimate for other metals such as gold, silver, mercury, platim n, tin, tungsten,
zirconium, etc., for which information is not given in this report.
B-7-38
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Utilization and Disposal of Bulk Waste Materials
Mine wastes, such as tailings, and heap and dump leachate piles, are managed in a
variety of ways. Mining wastes may be used on or off site, disposed of in waste piles, or used
in leach operations to recover additional valuable constituents from the ore or tailings still
present after milling processes have been completed. A small portion of the waste (less than
10 percent) has been used as backfill or for some oflsite uses. Table B.7-15 presents a partial
summary of the offsite use of bulk waste material associated with the metal mining industry.
Ofisite uses of mine waste tailings include the manufacturing of wallboards, anti-skid
products, use in making various construction aggregates, and use as fill or road base. The
most common use includes the production of concrete and bituminous aggregates for road
construction, in which such wastes are incorporated as an additive. Other applications in
road construction include the use of these wastes in road bases, in embankments, and to
make anti-skid surfaces. Taconite tailings have proved to be useful when applied as thin
(less than 25 mm) road surface overlays because they greatly enhance skid resistance.
Approximately half of the zinc tailings generated in Tennessee are sold for aggregate
production. Tennessee zinc tailings are also used as a substitute for mortar or agriculture
limestone, with nearly 40 percent being sold for these purposes. Tailings from mills
processing ores in New York and the Rocky Mountain states are not suitable as soil
supplements because as they have lower concentrations of calcium carbonate and higher
concentrations of lead and cadmium. Similar concerns constrain the use of lead tailings in
Missouri.
Tailings from molybdenum mining operations have been used in asphalt mixes to
resurface roads and parking lots. Gold and silver tailings, in the form of sand and gravel,
have been mixed with cement to form concrete for road construction. Lead, zinc, and iron ore
tailings have been used for both concrete and bituminous aggregates. Mixtures of crushed
waste rock, including waste material from copper, iron ore, lead, gold, and silver mines, have
been used in embankments, as backfills, or as pavement bases for many highways.
Depending upon the final use, topsoil covers have been placed over fills and embankments
made with these materials to control erosion and permit vegetative growth.
B-7-39
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Table B.7-15. Uses of mine waste and tailings.8
Material
and Use
Son
supplement
Wall board
Brick and
block
Gold&
Conner Silver
1 1
Iron Ore
& Taconite
1
3
Lead Molybdenum
Zinc
1
Anti-skid
products
Embankments
General
aggregate
Filler
pavement
base
Asphalt
Concrete
aggregate
3
3
a Data extracted from SCA88.
b Application codes:
1. Bench-scale research project.
2. Full-scale demonstration project.
3. Full-scale, sporadically practiced.
3
3
3
3
B-7-40
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The use of tailings to produce bricks, blocks, and ceramic products is still at the
bench-scale research stage. Copper mill tailings can be used in brick production if pyrites are
first removed. Lightweight blocks made from taconite' tailings have good structural
characteristics, but have not been marketed. However, mining wastes are competitive only
when they can be marketed or used in the geographical area close to the point of generation.
The costs of handling, and of transportation over large distances, more than ofiset their low
cost and large supply. As a result, the use of such mining wastes does not and will not keep
pace with the 1 billion metric tons that are generated each year. Accordingly, a large portion
of mining wastes and tailings are disposed in impoundment facilities near the mines and
mills where they are produced.
Actual or potential uses of slag tailings generated from smelting and refining raw ores
to produce primary metals are shown in Table B.7-16, summarized from the information
presented previously in this chapter. Major uses include aggregate in the production of
asphalt and concrete, as railroad ballast, and as anti-skid material.
Twenty-Year Waste Generation Estimates
In 1986, metal mines generated approximately 1 billion MT of wastes, of which 300
million MT consisted of tailings. Over the last 20 years, the production of wastes from
mineral processing plants has increased somewhat, but this increase may not necessarily
reflect an industry-wide trend. For example, some segments of the industry may experience
growth while others may see a downturn. The net effect, in the aggregate, is that there may
not be any significant changes. Accordingly, a reasonable approach is one which assumes a
nearly constant waste production rate of about 1 billion MT per year, yielding a 20 billion MT
inventory for the next 20 years. This would result in a 20-year production of 6 billion MT of
tailings.
This estimate is somewhat speculative since the mineral mining industry is not fully
represented in this report and there is not enough information to completely characterize
those NORM waste sectors that are discussed. The extent to which additional sectors would
add to the proposed total 20-year inventory is unknown at this point. As with most U.S.
B-7-41
-------
Table B.7-16. Uses of mineral processing slag.1
Mineral
Use
Asphalt Aggregate
Concrete Aggregate
Fill
Railroad Ballast
Road Base
Anti-Skid Products
Brick and Block
Soil Supplement
Pipe Bedding
Air Blasting Abrasive
CoDDer
X
X
X
X
X
X
Ferrous
Zinc Metals
X X
X
X
X X
X X
X X
X
Lead
X
X
X
X
X
X
a Summarized from information presented in this chapter.
B-7-42
-------
ndustry, the mineral mining and processing sector is also subject to competitive forces and
;he installation of additional productive capacity by foreign concerns. It is not known to what
jxtent the U.S. industry has attempted to adjust in response to foreign competitors. Finally,
-he use of mining waste in a variety of productive applications is not likely to impact future
vaste inventories since the development and implementation of new applications will not
ceep pace with the 1 billion metric tons that are generated each year.
1A RADIOLOGICAL PROPERTIES OF MINERAL PROCESSING WASTES
7.4.1 Radionuclide Concentrations
From the limited amount of data available that characterize mineral tailings and
vastes, it appears that the ores, tailings, and residues from different metal mining and
processing industries possess widely different radiological properties. Except for tailings from
;he uranium and phosphate rock mining industries (which are discussed separately in
preceding sections), the concentrations of uranium and thorium, including their decay
products, in mineral processing wastes and tailings have not been widely evaluated. Based
3n limited data, it appears that ores and tailings of most of the metal processing industries
:ontain relatively low concentrations of radium-226, typically less than a few pCi/g. However,
it also appears that some metal ores may contain elevated levels of uranium and thorium
require further characterization.
This is particularly true for titanium and zirconium and its subsequent processing and
for copper ores. The tailings and residues of the industries that process rare earths, such as
oionazite (rare metals and thorium), zircon sands (zirconium), columbium and tantalum, and
the titanium ores of ilmenite, rutile and leucoxene have been known to have elevated levels
of Ra-226. It appears that these elevated radionuclide concentrations are a result of the
chemical beneficiation processes employed in these industries.
With the copper mining industry, on the other hand, the potential source of NORM
wastes resides in the remaining mining spoils and overburden which are known to be rich
B-7-43
-------
in uranium ores. The presence of U3O8 in such waste has been observed at relatively high
concentrations and, particularly in copper wastes from Arizona and New Mexico, on the same
order of magnitude as those traditionally found in uranium mines. No numerical data on the
radiological properties of tailings and wastes from mining' iron ores, which represent the
second largest volume of metal mining wastes (after copper wastes), could be found for
inclusion in this report.
The source term used to assess the risks from mineral processing NORM is shown in
Table B.7-17. This source term is representative of radionuclide concentrations reported in
this section for titanium and zirconium wastes, and may also be typical of radionuclide
concentrations in the tailings from copper mines in the southwestern U.S. The Pb-210 and
Po-210 concentrations were estimated by assuming a radon emanation coefficient of 0.3.
U-235 was assumed to be present at a concentration of 5 percent that of U-238.
7.4.2 Radon Flux Rates
Other than the information presented above, no readily available data were identified
characterizing radon emanation rates from such waste forms. Radon emanation rates may
be assumed to be nearly identical to that of typical soils. For example, the NCRP notes that
for typical soils, an average radon surface flux rate is about 0.5 pCi/m2-s per pCi/g (NCR87).
Given higher Ra-226 concentrations, e.g., 35 pCi/g (see above), the corresponding radon flux
rate is estimated be at least 18 pCi/m2-s, other things being equal. It should be noted that
this radon flux rate is a very speculative estimate given the varied distribution of these waste
forms and their associated physical and chemical properties.
7.4.3 External Radiation Exposure rates
Radiation exposure rates associated with mineral processing wastes are expected to
vary from relatively low to significantly higher levels for some of the waste forms known to
have elevated radionuclide concentrations. For example, exposure levels as high as several
hundred uR/h have been observed from monazite wastes. Depending upon the source of
radioactivity, radiation levels may vary significantly because many of the decay products may
B-7-44
-------
Table B.7-17. Radionuclide source term for mineral processing wastes.
Nuclide Concentration (pCi/g)
4
Po-210 25.0
Pb-210 25.0
Ra-226 35.0
Ra-228 10.0
Th-228 10.0
Th-230 35.0
Th-232 10.0
U-234 35.0
U-235 1.8
U-238 35.0
B-7-45
-------
nc longer be in secular equilibrium with uranium and thorium. This is especially true with
or concentrates which are subject to chemical extraction since the process may selectively
de )lete or enrich some of the decay products.
Given the disposal method and the mode of exposure, radionuclides, and source to
re eptor geometry, it can be assumed that the resulting radiation doses may be scaled up
be ed on empirically derived exposure rate conversion factors for environmental conditions.
Tl 3 conversion factors represent typical soils and include the effects of gamma ray scatter,
bt Id-up, and self-absorption (NCR87). This approach is valid for large quantities of waste,
w: ich for practical purposes may be assumed to represent an infinite plane or slab source.
Fc example, the conversion factors for the uranium and thorium decay series are 1.82 and
2.. 2 uR/h per pCi/g, respectively. Assuming a U-238 and Th-232 concentration of 35 and 10
p( 7g, respectively, the total incremental exposure rate is estimated to be about 90 uR/h. In
th United States, ambient exposure rates due to terrestrial radiation are known to range
fr« ai 3 to 16 uR/h (NCR87).
7.. GENERIC SITE PARAMETERS AND SECTOR SUMMARY
7. .1 Generic Mineral Processing Waste Site
The generic site for the metal mining and processing waste risk assessment represents
a irge mine and mineral processing plant. The generic mine and mill site are assumed to
be Located in southern Arizona where ore associated with copper, precious metals, and other
m lerals are believed to have elevated levels of uranium. The model site consists of a
co amingled waste rock, overburden, and a tailings pile of 50 hectares. The tailings have no
kr jwn value other than reprocessing for their mineral content. The site is located in an area
wi h an average population density. The pile is approximately squared with dimensions of
7C ) m by 700 m, with a height of 30 meters. Assuming a density of 2 g/cm3, this results in
a ile of 30 million MT of tailings, overburden, and wastes. The site is also assumed to be
lo< ated near a surface stream and the region is underlain with an aquifer.
B-7-46
-------
While there is evidence to believe that certain ores cont: in quantities of pitchblende,
the model mine is based on the assumption that during mining and milling this material is
diluted through mixing, with average U-238 and Th-232 (inc ading their decay products)
concentrations of 35 pCi/g and 10 pCi/g, respectively.' 1. is difficult to judge the
representativeness of these values, except that the data inc icate that a portion of the
overburden and tailings could contain such levels of naturally- >ccurring radioactivity.
The September 1989 draft assessment contained an ana. /sis of the risks from a small
waste pile with elevated U-238 and Th-232 concentrations as urned to be typical of a few
sites in the southwestern U.S. Only a few such sites may exist i i isolated locations, and they
are not considered representative of mineral processing wash sites. Therefore, the small
waste site with higher radionuclide concentrations was not inch ied in this updated analysis.
7.5.2 Population Distribution
The generic site is assumed to be located in a rural are: in Arizona. The population
density is assumed to be 46 persons per square mile (average jr Arizona) (BOC87).
7.5.3 Radionuclide Concentrations
The above discussions revealed that the overburden of o 33 mined in the U.S. and the
slag and tailings from processing these ores do not generally apj jar to contain elevated levels
of naturally-occurring radionuclides. However, some of the i isidues associated with the
processing of both domestic and imported ores, and some of thi overburden associated with
the copper mining industry, may contain elevated concentration of radionuclides which could
result in increased exposures to the general public. This is espec ally true for the tailings and
residues associated with the processing of minerals, such as m nazite, zircon, ilmenite, and
rutile. This is also the case for the production of tin, titaniu a, zirconium, and hafnium.
Furthermore, some of these wastes may become dispersed int< the environment since they
may be used in various applications, e.g., incorporation in roa Is and building materials or
dispersal in agricultural fields.
B-7-47
-------
For t*"« risk assessment the source term is based on a Ra-226 concentration of
35 pCi/g which is representative of radionuclide concentrations reported in this section for
tin, titanium, and zirconium wastes and for copper tailings from mines in the southwestern
U.S. The members of the U-238 and Th-232 decay series are assumed to be in equilibrium
with their uranium and thorium parent nuclides, and the radon emanation coefficient is
assumed to be 0.3.
B-7-48
-------
B.7 REFERENCES
BEA89 Richard Beard, Arizona Department of Mineral Resources, Tucson, AZ, 1989,
Personal Communication, Department of Mines and Mineral Resources,
Phoenix, AZ.
BOC87 Bureau of the Census, Statistical Abstract of the United States - 1988, 108th
Edition, Department of Commerce, Washington, DC, December 1987.
BOM90 U.S. Bureau of Mines, Mineral Community Summaries, 1990 edition, p. 191.
CRC87 NORM in Mineral Processing, by Donald W. Hendricks, 19th Annual National
Conference on Radiation Control, May 18-21 1987. Boise, ID, February 1987,
Published by Conference of Radiation Control Program Directors, Inc.,
Frankfort, KY.
CRC81 Natural Radioactivity Contamination Problems, Report No. 2, August 1981,
Published by Conference of Radiation Control Program Directors, Inc.,
Frankfort, KY.
DOI89 Minerals and materials, A Bimonthly Survey, February - March 1989, Bureau
of Mines, U.S. Department of the Interior, Washington, DC.
DOI87 Minerals Yearbook, Vol. 1, Metals and Minerals, Bureau of Mines Department
of Interior, Washington, DC.
DOI85 Zirconium and Hafnium, A Chapter from Mineral Facts and Problems, 1985
Edition, United States Department of the Interior, Washington, DC.
EPA90 Report to Congress on Special Wastes from Mineral Processing,
EPA/530-SW-90-070C, July 1990, Office of Solid Waste and Emergency
Response, Washington, D.C.
EPA85 Report to Congress: Wastes from the Extraction and Beneficiation of Metallic
Ores, Phosphate Rock, Asbestos, Overburden from Uranium Mining, and Oil
Shale, EPA 530-SW-85-033, December 1985, Office of Solid Waste and
Emergency Response, Washington, DC.
EPA83 Evaluation of Management Practices for Mine Solid Waste Storage, Disposal,
and Treatment, Vol I, Characterization of Mining Industry Wastes (Draft), U.S.
EPA, Resource Extraction and Handling Division, Industrial Environmental
Research Laboratory, Office of Research and Development, Cincinnati, OH.
EPA82a Emissions of Naturally-Occurring Radioactivity from Aluminum and Copper
Facilities, EPA 520/6-82-018, November 1982, Office of Radiation Programs,
Las Vegas Facility, Las Vegas, NV.
B-7-R-1
-------
EPA82b Environmental Protection Agency, Emissions of Naturally Occurrir j
Radioactivity. Underground Zinc Mine and Mill, EPA-520/6-82-020, Novemb(
1982, Office of Radiation Programs Las Vegas Facility, U.S. EPA, Las Vega ,
Nevada.
EPA79 Performance Evaluation of an Electrostatic Precipitator Installed on a Coppi r
Smelter Reverberatory Furnace, EPA 600/2-119, June 1979, Industri. 1
Pollution Control Division, Industrial Environmental Research Laborator ,
Cincinnati, OH.
EPA78a Environmental Assessment: Primary Aluminum, United States Environment. I
Protection Agency, Industrial Environmental Research Laboratory, Cincinnai ,
OH, Nov. 1, 1978 (pre-publication copy).
EPA78b Environmental Assessment: Primary Copper, Lead, and Zinc, United State ;
Environmental Protection Agency, Industrial Environmental Researc i
Laboratory, Cincinnati, OH, Nov. 1, 1978 (pre-publication copy).
GRA89 Roy GrosshofT, Private Communication, August 16,1989, Office of Infonnatio ,
Education, and Administration, Texas Department of Health, Austin, Texa:
HU85 Hu, S.J., Radium-226 and Thorium-232 Concentration in Amang, Healt i
Physics 49, No. 5, p. 1003, 1985.
MCD89 John McDonnell, Roy F. Weston, Inc., Albuquerque, NM, 1989, Person 1
experience and communication.
NCR87 National Council on Radiation Protection and Measurements, Exposure oft! J
United States Population and Canada from Natural Background Radiatio ,
NCRP Report No. 94, Bethesda, MD, December 1987.
PEI70 Coal, Oil, Natural Gas, Helium, and Uranium in Arizona, by H. Wesley Peirc ,
S. B. Keith and J.C. Wilt, 1970 Arizona Bureau of Mines Bulletin 18 ,
Available through Arizona Geological Survey, Tucson, AZ.
SCA88 SC&A, Inc. Technical Supplements for the Preliminary Risk Assessment f
Diffuse NORM Wastes - Phase I, prepared under U.S. EPA contract N .
68-02-4375, October 1989.
STI62 Still, A.R., Uranium at Copper Cities and other Porphyry Copper Deposit ,
Miami District, Arizona (unpublished thesis), Harvard University, Cambridg ,
MA (1962).
USG63 Mineralogy, Internal Structural and Textural Characteristics, and Paragenes i
of Uranium-Bearing Veins in the Conterminous United States, by George \ .
Walker and John W. Adams, 1963, Geological Survey, Professional Papt r
455-D.
B-7-R-2
-------
USG55 Geology and Ore Deposits of the Bagdad Area, Yavapai County Arizona, by C.
A. Anderson, E. A. Scholz, and J.D. Strobell, Jr., 1955, Geological Survey
Professional Paper 278.
B-7-R-3
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B.8 GEOTHERMAL ENERGY PRODUCTION WASTE
8.1 INTRODUCTION
Geothermal energy can be defined as heat energy stored or produced in the earth.
This energy resource includes high-temperature crustal rocks, sediments, volcanic deposits,
water, steam, and other gases which occur at accessible depths from the earth's surface, and
from which heat can be economically extracted now or in the future. The earth's crust
represents an enormous reservoir of thermal energy. The U.S. Geological Survey estimates
that about 1.2 million quads (a quad is a unit of heat energy equal to one thousand trillion
- i.e., 1015 British Thermal Units) of geothermal energy resources exist in the uppermost
10 kilometers of the crust (EPA87).
Geothermal energy resource systems may be classified into four major categories:
Hot igneous systems - created by the buoyant rise of molten rock
(magma) from deep in the crust. In hot igneous systems, the rock is either
completely or partly molten (temperature greater than 650*C).
Hot dry rock systems heated impermeable rock that may or may not
have been molten at one time (temperature less than 650*C).
Geopressured systems - characterized by the presence of hot fluids under
high pressure, containing dissolved hydrocarbons, usually found in deep
sedimentary basins with a low level of compaction and a relatively
impermeable caprock. These systems reach moderately elevated
temperatures (temperature 90* to 200'C).
Hydrothermal systems - usually found in porous sedimentary rock or in
fractured rock systems, such as volcanic formations. The two classes are
vapor-dominated systems, which contain mostly steam (temperature 180*
to 200*C), and liquid-dominated systems (temperature 30* to 350"C).
The first three categories contain the most heat energy, but the technology does not
yet exist to exploit them. Current research is aimed at removing the technological barriers
that prevent the development of these resources.
B-8-1
-------
The technology exists to economically extract energy from the fourth category,
hydrothermal systems. Hydrothermal systems consist of high-temperature water and/or
steam trapped in porous and permeable rock reservoirs. The heat available in the
geothermal rock reservoirs is exploited by means of wells that bring hot water and/or steam
to the surface. Identified hydrothermal systems with temperatures greater than or equal to
90*C are located mostly in the western U.S. - primarily in the states of California, Oregon,
and Nevada.
The utilization of geothermal energy requires drillholes for the withdrawal of high
temperature fluids from the ground, surface utilization equipment (e.g., steam turbines or
heat exchangers and associated fluid handling equipment), and a fluid disposal system (e.g.,
percolation ponds or reinjection wells). At each stage of the geothermal utilization process,
the natural hydrothermal fluids, which may have been at thermal and chemical equilibrium
with the rocks and minerals in the geothermal reservoir, can experience substantial changes
in temperature, pressure, and pH values. These changes can affect the solubility of the
various dissolved minerals in the hydrothermal fluids, causing these minerals to precipitate
out and form scale or sludge on the inside surfaces of the equipment used to extract and
utilize the steam and briny liquids that constitute the geothermal resource.
As is the case for geological formations from which oil and natural gas are obtained
(see Section B.5), both uranium and thorium and their radioactive daughters may be present
in underground formations from which geothermal fluids are extracted. Uranium and
thorium are highly insoluble; however, radium is slightly soluble and may be brought to the
surface and deposited with the scale or sludge that coats the inside surfaces of geothermal
energy production systems. The concentrations of NORM in geothermal wastes will vary
with the nature and location of the geothermal resource and with the physical and chemical
changes that take place as this resource is extracted and utilized.
Geothermal energy currently makes a relatively minor contribution to total energy
production in the U.S. Most of the effort in characterizing the wastes from utilization of this
resource has been directed at identifying the chemical properties of these wastes, including
the chemical species, corrosivity, and chemical toxicity. Only very limited attention has been
paid to characterizing the radiological properties. Consequently, the radiological hazards are
not well understood, and only limited data on NORM concentrations are available. The EPA
B-8-2
-------
has published a report to Congress on the management of wastes from geothennal energy
(EPA87) which includes some information on radium concentrations in geothennal wastes.
An Environmental Impact Report prepared in support of an application for a monofill
disposal facility for wastes from a liquid-dominated system in California's Imperial Valley
(ERC90) includes some radium concentration data for these, wastes. Additional studies are
needed to adequately characterize the radioactive properties of geothennal wastes.
In the following sections, descriptions are provided of the geothennal energy industry
and of the properties of geothennal wastes. Also provided are projections of the quantities
of waste that might be produced by this NORM sector. This information is used to assess
potential exposures and health impacts to members of the general public and critical
population groups. A radiological risk assessment is performed (see Chapter D) assuming
that both exposed populations reside near a generic site.
8.2 OVERVIEW OF THE GEOTHERMAL ENERGY INDUSTRY
Geothennal energy is currently used in the U.S. in two commercial applications:
production of electrical power and as a direct source of heat. An indication of the extent of
geothermal resource development and use can be obtained by examining data on recent
geothermal well drilling operations. Table B.8-1 presents data on the locations of geothermal
drilling activities in the U.S. during the years 1981 through 1985 (WIL86). The numbers of
wells include both exploratory wells drilled to confirm the existence and determine the extent
of the geothennal resource, and wells drilled for development and use. Thermal gradient
holes, which are holes drilled to measure the temperature profile, are not included in the
tabulation. As shown in the table, California has, by far, the most geothermal development
activity. The Geysers, in Sonoma County in northern California, and the Imperial Valley in
southern California are the primary development sites.
B-8-3
-------
to 1985. (Source: WIL86)
Number of Wells
State
Alaska
California
Colorado
Hawaii
Idaho
Louisiana
Montana
Nevada
New Mexico
New York
Oregon
Texas
Utah
Washington
1981
55
1
2
6
1
14
6
3
2
1982
4
67
~
1
-
1
2
3
1
1
2
1
1983
47
-
3
1
4
3
-
1
1
1
-
1984 1985 Totals
>
4
88' 64 321
1
_ - 3
_. 9
1
_ 2
3 3 26
12
_ 1
-15
2
2-5
3
Totals
90
83
61
93
68
395
B-8-4
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8.2.1 Electrical Power Production
Economically viable methods exist for producing electrical power from either
vapor-dominated or liquid-dominated hydrothermal systems. In vapor-dominated systems
the high temperature steam can be used directly to turn a. turbine-generator and produce
electricity. In liquid-dominated systems, hot saline waters (the brine) can transfer heat to
a secondary working fluid or can be converted to steam by a flashing process.
In a vapor-dominated system, electrical power is generated using a conventional steam
cycle (Figure B.8-1). Typically, 10 to 14 wells are required for a 50-megawatt plant. The
production wells are connected to a gathering system (manifold), and steam from the wells
provides direct power to drive the turbine generator. A separator is located on the main
steam line to remove solids from the steam prior to entry into the turbine. The exhaust
steam from the turbine is condensed in a cooling tower which also acts as a concentrating
unit for dissolved solids in the condensate. Some condensate is re-used as a cooling medium.
Excess condensate is processed to remove suspended solids and is then injected back into the
geothermal reservoir. The sludge is dewatered and the resulting filter cake is stored or
disposed in accordance with applicable state regulations.
The Geysers is California is the largest vapor-dominated geothermal electrical
generating complex in the world. As of 1987, 24 plants were in operation with a combined
generating capacity of about 1,800 megawatts (EPA87).
Electricity is produced from liquid-dominated reservoirs by using either of two
processes: the flash process and the binary process. Schematics of these processes are shown
in Figures B.8-2 and B.8-3.
In the flash process, the geothermal brine is "flashed" to produce steam. The flash
process is the partial evaporation to steam of the hot liquid brine by the sudden reduction
of pressure in the system. The steam is fed directly to the turbine, with subsequent usage
and disposal as described above for vapor-dominated systems. Several power plants in
California's Imperial Valley that extract energy from liquid-dominated systems use a flashing
process to generate electricity.
B-8-5
-------
Turbine Generator
Cooling 'ower
\
Removal
Solids
Separator
Condenser
Manifold
Production Wells
Y
To
Injection
Wells
i-103353
Figure B.8-1. Schematic of electric power production from a vapor lominated system.
B-8-6
-------
Turbine Generator
Flash
Separator
To
Injection
Wells
From
Production
Wells
Gas
Removal
CP
Cooling Tower
Condenser
To
Injection
Wells
RAE-103355
Figure B.8-2. Schematic of flashed-steam process for producing electric
power from a liquid-dominated system.
B-8-7
-------
Turbine Generator
Heat
Exchanger
o
From
Production
Wells
To
Injection
Wells
Cooling Tower
To
Injection
Wells
Makeup
Water
RAE-103354
Figure B.8-3. Schematic of binary process for producing electric power
from a liquid-dominated system.
B-8-8
-------
In the binary process, the hot brine transfers heat to a working fluid whi< i then
expands through the turbine and drives the electric generator. The Heber Demon; .ration
Plant in California's Imperial Valley is the largest binary power plant in the worlc This
plant uses a binary conversion process consisting of three fluid loops: a geothermal loop, a
hydrocarbon working-fluid loop, and a cooling water loop. In the heat exchanger, tk i brine
and hydrocarbon are contained in separate closed loops, allowing no direct contact I :tween
loops. The hydrocarbon vapor expands through the turbine which drives the gei arator.
Spent brine is injected back into the geothermal reservoir. The brine temperature i ust be
maintained above 65*C to restrict precipitation of dissolved solids during injection.
Even though the total production of electrical power from geothermal source in the
U.S. remains small, a significant increase in geothermal power production occurra in the
decade between 1980 and 1990. At the close of 1986, 2,000 megawatts of geoi lermal
generating capacity were available in the U.S. (GEO87). At the close of 1989, tl 3 total
geothermal generating capacity had risen to 2,500 megawatts (GEO90). Table B.8-2 ists 29
geothermal power facility sites that were either operating or under construction in t .e U.S.
in 1987 (EPA87). These sites had a combined generating capacity of almost 2,600 meg .watts.
A "site" is defined as either a single power plant or a multiple operating unit. For e. ample,
power-generating facilities at The Geysers are shown as seven sites, although the e sites
contain more than 25 operating units, owned by different power companies.
Table B.8-2 shows that geothermal power plants are typically small, of the « rder of
a few tens of megawatts. In 1987, California had approximately 96 percent of tl a total
geothermal electrical capacity in the U.S. The remaining four percent was located : i other
western states and Hawaii. In 1987, approximately 85 percent of the total ger mating
capacity in the U.S. came from vapor-dominated facilities at The Geysers in n rthern
California.
8.2.2 Direct Use of Geothermal Energy
In some areas of the country it has been found efficient and economical to use
geothermal energy as a direct source of heat. Sites that have made direct use of geoi lermal
heat are widespread but are located mostly in the western U.S., in the states of Ca fornia,
B-8-9
-------
Table R8-2. Geothermal plants for electricity generation (Source: EPA87)
Name
East Mesa
East Mesa
East Mesa
Heber
Heber
Salton Sea
Salton Sea (Vulcan)
Coso
Wendell-Amedee
Wendell-Amedee
Mono Long Valley
The Geysers
The Geysers
The Geysers
The Geysers
The Geysers
The Geysers
The Geysers
Puna No. 1
Lighting Dock
Brady Hazen
Dixie Valley Oxbow
Fish Lake
Owner
Ormat
Ormat
Magma Power Co.
Heber Geothermal
Co.
SDG&E Binary
Demo
Unocal
Magma Power Co.
California Energy
Co.
Geoproducts
Wineagle Developer
Mammoth Pacific
Pacific Gas &
Electric
Sacramento
Municipal Utility
District
Northern California
Power
California
Department of
Water Resources
Freeport Macmoran
Santa Fe
Geothermal
Copa
Helco
Burgett Floral
Chevron
Oxbow Geothermal
Steam Reserve
State/
County
CA/Imperial
CIA/Imperial
CA/Imperial
CA/Imperial
CA/Imperial
CA/Imperial
CA/Imperial
CA/Inyo
CA/Lassen
CA/Lassen
CA/Mono
CA/Sonoma
CA/Sonoma
CA/Sonoma
CA/Sonoma
CA/Sonoma
CA/Sonoma
CA/Sonoma
Hi/Hawaii
Island
NM/Hidalgo
NV/Churchill
NV/Churchill
NV/Esmeralda
Process
Tvne
LPB
LPB
LPB
LPF
LPB
LPF
LPF
LPF
LPH
LPB
LPB
VPS
VPS
VPS
VPS
VPS
VPS
VPS
LPF
LPB
LPB
LPF
LPB
Electrical
Capacity
(MW)
12.0
24.0
12.5
47.0
45.0
15.0
34.5
25.0
20.0
0.6
7.0
1560.0
72.0
220.0
55.0
80.0
80.0
150.0
3.0
0.9
8.3
50.0
15.0
Status8
UC
OP
OP
OP
OP
OP
OP
OP
UC
OP
OP
OP
OP
OP
OP
OP
OP
UC
OP
OP
OP
UC
UC
Corp.
B-8-10
-------
Table R8-2. (Continued)
Name
Beowawe
Wabuaka Hot Springs
Desert Peak
Steamboat Springs
Cove Fort -
Sulphurdale
Roosevelt Hot
Springs
Owner
Crescent Valley
Geothermal
Tad's Enterprises
Chevron/Sierra
Pacific Power Co.
Geothermal
Development
Association
CityofProvo
Utah Power &
Light
State/
County
NV/Lander-
Eureka
NV/Lyon
NV/Reno
NV/Washoe
UT/Beaver
UT/Beaver
Process
Type
LPP
LPB
LPP
LPB
LPB
LPP
Electrical
Capacity
(MW) Status*
17.0
0.6
9.0
5.4
4.7
20.0
OP
OP
OP
OP
OP
OP
a. Status as of 1987.
Key for Process Type
First Letter
V - Vapor
L - Liquid
Second Letter
Third Letter
P - Power Generation
Status
F - Flash Process
B - Binary Process
S - Conventional Steam
H - Hybrid
OP - Operating
UC - Construction
B-8-11
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^Oregon, Idaho, Nevada, New Mexico, Utah, and Colorado. Geothermal heat has been used
for homes, offices, schools, commercial'buildings, pools, greenhouses, and fish farms. This
heat can be extracted from the condensate from an electrical generating facility or directly
from a geothermal production well.
The two most common ways of utilizing geothermal energy as a direct source of heat
are through downhole and surface heat exchangers. Some 400 to 500 shallow wells are used
for space heating in the Klamath Falls and Klamath Hills, Oregon, geothermal areas (LIE86).
These wells provide heat for about 500 homes, offices, commercial buildings, schools,
churches, and greenhouses. Typically, well temperatures range from 38*C to 110'C. Most
of the wells use downhole heat exchangers, which consist of one- or two-tube loops suspended
in the wellbore, in direct contact with the hydrothermal fluid. Downhole exchangers are
feasible only where reservoir depths are typically less than 500 feet. Usually, the water
inside the heat exchanger cycles thermally, eliminating the need for pumps or for fluid
disposal.
Surface exchange systems require extraction of the geothermal fluid from the reservoir
and, subsequently, some means of spent fluid or brine disposal. The Pagosa Springs
Geothermal District space heating system in Colorado has successfully used low temperature
(60"C) geothermal fluid in a surface exchange system to heat public buildings, schools,
residences, and commercial establishments at significantly lower cost than with conventional
fuels (GOE84).
8.3 GEOTHERMAL ENERGY WASTE
Geothermal energy wastes include wastes from exploration and development of
geothermal systems, wastes from electrical power production, and wastes from direct use of
geothermal energy.
B-8-12
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8.3.1 Exploration and Development Wastes
Well drilling activities from geothermal exploration and development generate large
quantities of wastes consisting of discarded drilling muds 'and residues from drilling mud
cleaning processes. Drilling mud is a formulation of clay and chemical additives, such as
caustic soda or other materials, in a water base. Solids are removed from used drilling muds
by circulation of the mud through equipment such as shale shakers, sand traps,
hydrocyclones, and centrifuges. After cleaning, the mud is recycled to the drilling operation
and the removed solids are disposed of as waste residue. When drilling is completed, the
used muds are discharged to reserve pits for storage or disposal.
8.3.2 Geothermal Power Plant Wastes
Wastes generated from geothermal power production include both liquids and solids.
Liquid wastes include excess steam condensate from vapor-dominated systems and spent
brines from liquid-dominated systems. In vapor-dominated systems, the exhaust steam from
the turbine is condensed and pumped to a cooling tower where it is cooled. Excess
condensate is processed to remove suspended solids and then injected back into the
geothermal reservoir. Spent brines from liquid-dominated systems are also processed to
remove solids and injected back into the geothermal reservoir.
Solid wastes include piping and flash tank scale, sludges from processing of steam
condensate to remove solids, separated solids from pre-injection treatment of spent brines,
and hydrogen sulfide abatement wastes. The bulk of solid wastes from geothermal power
production originate from the treatment of spent brines at liquid-dominated systems. The
vapor resources at The Geysers are characterized by a dissolved solids content as low as the
parts-per-million level; while the hot saline fluids of the Imperial Valley may have a dissolved
solids content approaching 30 wt percent (THO89).
During geothermal power production operations, scale forms in process lines, valves,
and turbines as the temperature and pressure are reduced and as the pH of the system
changes as a result of the release of carbon dioxide. The scale generally consists of barium,
calcium, and strontium salts (carbonates, sulfates, and silicates) and silica. The amount and
B-8-13
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composition of this scale depends upon the site's mineralogy and the process used for power
production. Especially at liquid-dominated facilities, the scale must be periodically removed
to ensure proper operation of the power production equipment. As is the case for oil and gas
production scale, geothermal scale may contain small amounts of radium and radium
daughters that are coprecipitated with the barium and calcium salts.
Brines produced at flash plants require treatment before injection because of their
very high dissolved solids content. One method of treating geothermal brine is to allow
precipitation of dissolved solids in spent-brine holding ponds. After sufficient time to allow
settling, the clarified liquid can be withdrawn from the end opposite the inlet and injected
into the producing reservoir. Solids accumulating in the pond are dredged, dried by
evaporation, and disposed of at a State-approved landfill.
Hydrogen sulfide abatement constituents include iron sulfide sludge and iron catalysts
used to precipitate hydrogen sulfide; emulsion waste from the froth tank, vanadium catalysts,
and elemental sulfur from the peroxide extraction process; and sulfur dioxide and sulfur
dioxide diluted with water. In California, these wastes are incinerated or placed in a
hazardous waste landfill.
Sufficient data are not available to accurately characterize either the volumes or the
NORM concentrations in solid wastes from geothermal energy production. Waste generation
information in the literature applies to only a few site-specific cases. Most of the available
information is from areas such as The Geysers and the Imperial Valley in California, which
have the most commercial activity. Since the characteristics of geothermal wastes relate
directly to the geology and mineralogy of a resource area, additional site-specific data are
required to more fully characterize geothermal industry wastes.
8.3.3 Waste Generation from Direct Users
The primary waste generated from using geothermal energy as a direct source of heat
is the spent geothermal fluid remaining after usable heat has been extracted. In most cases,
this fluid is considered to be of high enough quality to allow it to be discharged into nearby
B-8-14
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surface water bodies (EPA87). Significant amounts of solid wastes are not produced from
using geothermal energy as a direct source of heat.
8.3.4 Twenty-Year Waste Generation Estimate
The only significant NORM-contaminated wastes from utilization of geothermal energy
are the solid wastes from geothermal power production. These wastes are primarily piping
and flash te*nlc scale and the solid residues from brine treatment at liquid-dominated
facilities, such as those in California's Imperial Valley. Because of a scarcity of data, no
attempt is made in the EPA's report to Congress on management of wastes from geothermal
energy (EPA87) to quantify the solid waste produced at power generation facilities.
For thig assessment, the twenty-year waste generation estimate is based on a waste
generation rate identified in an Environmental Impact Report for a conditional use permit
for monofill disposal of geothermal wastes in Imperial County, California (ERC90). Power
rt
plants now operating in Imperial County are estimated to produce approximately 20,000 m
of geothermal filter cake annually. The assumption is made that waste generation, averaged
over the 20-year period, might double as additional plants are brought into operation.
Doubling this production rate and multiplying by 20 years results in an estimated 20-year
waste volume of 800,000 m3.
8.4 RADIOLOGICAL PROPERTIES OF GEOTHERMAL ENERGY WASTES
8.4.1 Radionuclide Concentrations
This radiological assessment is concerned with the radionuclides in solid waste. The
principal solid waste materials of concern are the scale in piping and production equipment
and the filter cake produced from treatment of the spent geothermal fluid prior to its
reinjection into the producing formation.
B-8-15
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As is the case for geological formations from which oil and gas are produced, uranium
and thorium and their radioactive daughters may be present in formations from which
geothermal fluids are extracted. The available information indicates that significant
quantities of uranium and thorium are not dissolved or entrained in the geothermal fluids.
This is similar to oil and gas production where NORM appears to be associated primarily
with the production water, and radium is essentially the only non-gaseous NORM
radionuclide produced. The primary radionuclides that appear to be produced with the
geothermal fluids are Ra-226 and Ra-228, from the uranium and thorium decay chains,
respectively.
There is very little information available on the concentrations of NORM in
geothermal solid waste. In the late 1970s, work was done by the EPA/ORP Las Vegas office
and others on radon releases associated with geothermal resource use. However, there
apparently has been minimal similar work done on the radionuclides in solid wastes. The
only definitive information on concentrations of radionuclides in geothermal solid wastes
identified for this assessment is contained in an Environmental Impact Report for a
conditional use permit for a monofill in which to dispose of geothermal wastes in Imperial
County, California (ERC90). This Environmental Impact Report provides results of the
analysis of samples from four geothermal power plants in the Imperial Valley. The
concentrations of radium in samples of filter cake from these plants were:
Ra-226: 10 to 254 pCi/g
Ra-228: 9 to 193 pCi/g
The solids are generally separated from the fluid in clarifiers. The lower concentrations were
observed in the second clarifiers, when more than one clarifier was sampled. The average,
volume weighted, concentrations for the six samples (two samples from two of the plants)
were:
Ra-226: 160 pCi/g
Ra-228: 110 pCi/g
The concentrations of the decay products were lower than for the parent radionuclides,
indicating that the long half-life decay products were not produced with the geothermal fluid.
B-8-16
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The analytical results indicated a Ra-226 emanation coefficient of about 25 percent, Pb-210
and Po-210 concentrations of about 110 pCi/g, and a Th-228 concentration of about 30 pCi/g.
The concentrations of the decay products will increase with ingrowth time.
8.4.2 Radon Flux from Geothermal Wastes
The geothermal solid wastes are presumed to be disposed of in landfill type disposal
cells of about four hectares. The radon flux from the materials will be a function of the
Ra-226 concentration and emanating power, the moisture content of the material, and the
porosity. The radon flux was estimated using the RAE radon diffusion code (ROG84). The
radon flux from an open cell is estimated to be about 160 pCi/m2-sec, using parameters for
material properties from several of the geothermal power facility sites in the arid Imperial
Valley. Extensive watering for dust control and placement of a 6-in interim cover reduces
the flux to 80 pCi/m2-sec during the operating period. A permanent post-operational cover
of about 3 meters placed over the disposed geothermal wastes would reduce the radon flux
to less than 20 pCi/m2-sec.
8.4.3 External Radiation Exposure Rates
There will be external gamma exposure associated with both Ra-226 and Ra-228 decay
products. There is some exposure in the power plants, but the primary potential for exposure
is at the disposal site, prior to placing the cover. The exposures at the power plant sites are
controlled through minimizing the accumulation of material and by the geometry of
equipment which contains the geothermal waste.
B-8-17
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8.5 SUMMARY OF GEOTHERMAL ENERGY NORM SECTOR
8.5.1 Generic Geothermal Solid Waste Disposal Site
The generic geothermal solid waste disposal site is assumed to be loca ad in an arid
area in southern California because 95 percent of geothermal electric generati ig capacity is
in the state of California. Most of the solid waste from geothermal power ^reduction is
produced from liquid-dominated systems located in the Imperial Valley anc surrounding
areas. Therefore, the risk assessment for this sector is based on the disposal of filter cake
from the pre-injection treatment of spent brine at a monofill facility in southe -n California.
The monofill facility is assumed to contain 400,00 m3 of geothermal sol 1 waste. The
designated disposal area occupies 100,000 square meters, with a depth of 4 meters. The
completed facility is assumed to incorporate a bottom composite liner consistir : of an 80-mil
thick high density polyethylene (HDPE) liner over 1 m of compacted clay wit a maximum
permeability of 10'7 cm/sec. The completed facility also has a composite :over system
consisting of 0.6 m of compacted clay topped by 2.0 m of topsoil. The cover it assumed not
to be put in place until the monofill is filled with waste. However, an interim c ver of 0.15 m
of clay is placed over the waste during operations, typically at the end of eac: week.
8.5.2 Population Exposure
The population density near and around the site is assumed to be the a erage for the
state of California, at 181 persons per square mile (BOC90). Since the likely >cation of the
disposal facility is a desert region in extreme southern California, the actx J population
density in the vicinity of the site may be much less than this.
8.5.3 Radiomiclide Concentrations
Elevated concentrations of uranium and thorium and their radioac ive daughter
products are sometimes present in hydrothermal systems from which geother aal fluids are
B-8-18
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extracted for use in the generation of electricity. The uranium and thorium are highly
insoluble and tend to remain in place in the underground reservoir. However, radium is
slightly soluble and may be transported to the surface with the geothermal fluids. As the
temperature, pressure, and pH of the fluid system change, ra'diuxn may coprecipitate with the
mineral salts that form a scale on the insides of pipes,, valves, and tanks, or it may
concentrate in the filter cake from processing the geothermal brine prior to injection back into
the reservoir. The concentration of radium in geothermal waste depends on its concentration
in the underground hydrothermal system and on the processes by which the geothermal fluid
is extracted and utilized in electric power production.
Little data are available to accurately characterize NORM concentrations in solid
wastes from geothermal energy production. Since the characteristics of geothermal wastes
relate directly to the geology and mineralogy of a resource area, significant variations in
radium concentrations may occur. Additional studies are needed to adequately characterize
the radioactive properties of this waste. For this risk assessment, radionuclide
concentrations in geothermal waste are based on information in an Environmental Impact
Statement for a proposed monofill for disposal of geothermal wastes in Imperial County,
California (ERC90). A Ra-226 concentration of 160 pCi/g and a Ra-228 concentration of
110 pCi/g are assumed, based on limited data from sampling filter cake from treating brine
extracted from liquid-dominated systems in the Imperial Valley. The Pb-210 and Po-210
concentrations are each assumed to be 110 pCi/g, and the Th-228 concentration is assumed
to be 30 pCi/g.
Although these values are based on limited information, they are similar to the
average concentrations of radium and radium decay products in solid waste from oil and gas
production. As previously noted, it appears the chemical and physical conditions for
mobilizing NORM in geothermal fluids are similar to that for oil and gas. Therefore, it is
reasonable to expect that the average radionuclide concentrations in geothermal waste solids
would be similar.
The GSX Laidlaw hazardous waste facility in Imperial County has applied for a
permit to construct sole use geothermal waste cells. In the permit application, GSX has
specified not to accept geothermal wastes with a radium concentration above 200 pCi/g.
Based on the stipulation of this operating condition, it would appear that the concentrations
B-8-19
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of 160 pCi/g of Ra-226 and 110 pCi/g of Ra-228 (total 270 pCi/g of radium) conservatively
reflect the concentrations of NORM that GSX expects may be present in the geothermal
wastes.
B-8-20
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REFERENCES
/
BOC90 Bureau of Census, Statistical Abstract of the United States - 1990, 110th
Edition, Department of Commerce, Washington, D.C., 1990.
EPA87 Environmental Protection Agency, Report to Congress: Management of Wastes
from the Exploration, Development, and Production of Crude Oil, Natural Gas,
and Geothermal Energy, Volume 2 of 3, Geothermal Energy,
EPA/530-SW-88-003, Office of Solid Waste, December 1987.
ERC90 ERG Environmental Energy Services Co., Final Environmental Impact Report
for General Plan Amendment, Zone Change, and Conditional Use Permit,
prepared for County of Imperial Planning Department, 1990.
GEO87 Wallace, R.H., Jr., and K.L. Schwartz, Geothermal Energy, Geotimes, Vol. 32,
No. 2, p. 28, February 1987.
GEO90 Reed, M.J., Geothermal Energy, Geotimes, Vol. 35, No. 2, p. 24, February 1990.
GOE84 Georing, S.W., et al., Direct Utilization of Geothermal Energy for Pagosa
Springs, Colorado, U.S. Department of Energy, Division of Geothermal and
Hydropower Technologies, 1984.
LJE86 Lienau, L.J., Status of Direct Heat Projects in the Western States, GHC
Bulletin, Fall 1986, pp. 3-7.
NCR75 National Council on Radiation Protection and Measurements, Natural
Background Radiation in the United States, NCRP Report No. 45, 1975.
ROG84 Rogers, V.C., K.K. Nielson, D.R. Kalkwarf, Radon Attenuation Handbook for
Uranium Mill Tailings Cover Design, NUREG/CR-3533, RAE-18-5, 1984.
THO89 Thomas, D.M., and J.S. Gudmundson, Advances in the Study of Solids
Deposition in Geothermal Systems, Geothermics, Vol. 18, No. 1/2, pp. 5-15,
1989.
WIL86 Williams, T. Department of Energy Comments on the Technical Report,
"Wastes from Exploration, Development, and Production of Crude Oil, Natural
Gas, and Geothermal Energy: An Interim Report on Methodology for Data
Collection and Analysis," 1986.
B-8-R-1
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CHAPTER D
RISK ASSESSMENT FOR DIFFUSE NORM
D.I INTRODUCTION
The results of evaluations of possible health impacts from the storage or disposal of
diffuse NORM wastes are presented in this chapter. These evaluations are based on the
waste inventories, generic site parameters, and radiological properties of the NORM waste
sectors described in Chapter B. Health impacts from the storage or disposal of NORM wastes
are estimated for workers at the storage or disposal sites, for onsite individuals, for persons
belonging to the critical population group (CPG), and for the general population in the
vicinity of the disposal sites.
Workers at the storage and disposal sites include disposal pile workers and office
workers. The disposal pile worker is an adult employee who works 2,000 hours per year,
spending 80 percent of his time on the waste pile. It is assumed that the waste pile is not
covered or capped. The worker uses machinery such as a grader or bulldozer which places
him one meter above the pile surface and provides some shielding from direct gamma
radiation.
The office worker also works 2,000 hours per year in a building located at the disposal
site. While in the building, the worker is exposed via the indoor radon inhalation pathway.
Although an office building would likely be located at some distance from the disposal pile,
in estimating the indoor radon concentration it is assumed that the building is located on the
pile. This results in a conservatively high estimate of the radon dose received by the office
worker.
The onsite individual is assumed to live on a site which was formerly used for the
disposal of diffuse NORM wastes. Exposures received by this onsite individual include
inhalation of radon gas and direct exposure to gamma radiation. For indoor exposure to
radon, the exposure fraction (i.e., the fraction of a year the person is exposed) is 0.75. For
D-l-1
-------
direct exposure to gamma radiation the equivalent exposure fraction is 0.5 which takes into
account the time spent outside plus the time spent indoors at a reduced exposure level.
The CFG includes those individuals who might be exposed to the highest doses as a
result of normal daily activities. For this assessment of the risk from diffuse NORM, the
member of the CFG is assumed to be an adult who lives in a house located 100 m from the
disposal pile. The person obtains all of his water from a well adjacent to the house. Fifty
percent of his foodstuffs are assumed to be grown onsite. Exposure pathways for which
possible health impacts are evaluated include direct gamma exposure, downwind exposure
to radon gas, inhalation of contaminated dust, and ingestion of contaminated water and
foodstuffs.
Several exposure pathways are evaluated for the general population residing near the
disposal sites. Population exposures are evaluated for both ingestion and inhalation exposure
pathways.
Dose and risk calculations are performed for the following individual and population
exposure scenarios:
Worker
Direct gamma exposure.
Dust inhalation.
- Indoor radon inhalation.
Onsite Individual
- Direct gamma exposure.
Indoor radon inhalation.
Member of CPG
- Direct gamma exposure.
Inhalation of contaminated dust.
Downwind exposure to radon.
- Exposure to NORM in building materials.
- Ingestion of drinking water from a contaminated well.
Ingestion of foodstuffs contaminated by well water.
Ingestion of foodstuffs contaminated by dust deposition.
Ingestion of foodstuffs grown on repeatedly fertilized soil.
D-l-2
-------
- Downwind exposure to resuspended particulates.
Downwind exposure to radon.
- Ingestion of river water contaminated via the groundwater pathway.
. Ingestion of river water contaminated via surface runoff.
- Ingestion of foodstuffs grown on repeatedly fertilized soil.
The exposure scenarios evaluated for each of the NORM waste sectors described in Chapter
B are shown in Table D.l-1.
Health impacts from exposures to diffuse NORM wastes are expressed both in terms
of committed dose equivalent (hereafter referred to as dose) and the probability that a fatal
cancer might result from exposure. Because the actual duration of an individual's exposure
to NORM waste is unknown and may vary depending upon the exposure scenario, all dose
and risk calculations are based on one year of exposure. For ingestion and inhalation
exposures, the calculated doses are expressed in terms of the 50-year committed dose
equivalent (mrem) from one year of exposure. For direct gamma exposure, the dose is
expressed in terms of the annual committed whole body dose equivalent (mrem/yr). For all
of the exposure pathways, the health effects are expressed in terms of the lifetime (70-year)
risk of a fatal cancer from one year of exposure.
The dose calculations are based on the PATHRAE dose assessment methodology
(EPA87a) and utilize equations derived from the PATHRAE methodology. The PATHRAE
dose assessment model was developed for the EPA to estimate doses to individuals from
low-level radioactive wastes disposed in a variety of land disposal settings. Thus, the
methodology used for these dose calculations is generally consistent with established EPA
models. The exposure models, model assumptions, and input parameter values used for these
dose and risk calculations are summarized in Section D.2 of this chapter. The results of
these dose and risk calculations are presented in Section D.3.
D-l-3
-------
Table D.M. Expoaure cenarloa for diffuse NORM risk aaeeMment
Exposure Scenario
Worker
Direct Gamma Eipoaure
Dual Inhalation
Indoor Radon Inhalation
Uranium
Overburden
X
X
X
Pboephato
Waste
X
X
X
Phosphate
Fertiliser
X
X
CoalAah
X
X
X
Water
Treatment
Sludge -
Fertiliser
Water
Treatment
Sludge -
Landfill
Mineral
Prooeaalng
Waate
Oil* Gas
Scale/Sludge
Geotbermal
Waate
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Onalte Individual
Direct Gamma Eipoaure
Indoor Radon Inhalation
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Member of CPQ
Direct Gamma Exposure
Inhalation of Contaminated Dust
Downwind Exposure to Radon
NORM in Building Materials
Ingealion of Drinking Water from a
Contaminated Well
Ingestion of Foodatufls Contaminated
by Well Water
Ingestion of Foodstuffs Contaminated
by Dust Deposition
Ingeation of Foodatufls Grown on
Repeatedly Fertilited Soil
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
General Population Near Disposal Sites
Downwind Exposure to Resuspended
Particulatea
Downwind Exposure to Radon
Ingeation of River Water
Contaminated Via the Groundwaler
Pathway
Ingeation of River Water
Contaminated by Surface Runoff
Ingeslion of Foodslufls Grown on
Repeatedly Fertilized Soil
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
-------
D.2 RISK ASSESSMENT METHODS
In thiq section, the exposure scenarios and models used to evaluate health impacts
from the storage and disposal of diffuse NORM wastes are described. Assumptions made in
using the models to estimate individual and population doses and health effects are
discussed. Values of the input parameters used in the dose equations are presented. As
already noted, the dose calculations utilize equations derived from the PATHRAE dose
assessment methodology. The data used as input parameters comes, in part, from the
characterizations contained in Chapter B and from data expressly developed in this chapter.
2.1 THE PATHRAE DOSE ASSESSMENT MODEL
The PATHRAE performance assessment model (EPA87a) was initially developed as
an analytical tool to assist the U.S. Environmental Protection Agency in developing standards
for low-level radioactive waste and below regulatory concern waste disposal. The PATHRAE
model provides estimates of health effects which could potentially occur if radioactive wastes
were disposed of in a near surface facility, sanitary landfill, or other geological setting.
PATHRAE has been used to calculate effective dose equivalents to members of the critical
population group from the disposal of radioactive wastes at sites located in diverse
hydrogeologic, climatic, and demographic settings. PATHRAE has also been modified to
consider population impacts from airborne exposures (ROG85).
An important advantage of the PATHRAE methodology is its simplicity while still
allowing a comprehensive set of radionuclides, disposal settings, and exposure pathways to
be analyzed. The effects of changes in disposal site and facility characteristics can be readily
investigated with relatively few parameters needed to define the problem.
The PATHRAE methodology models both off-site and on-site pathways through which
persons may come in contact with radioactivity from the waste. The off-site pathways include
groundwater transport to a well and to a river, surface water transport to a river, and
D-2-1
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atmospheric transport. On-site pathways include direct gamma exposure, dust inhalation,
and pathways by which post-closure reclaimers or intruders onto a site might become exposed
by such activities as building a house and living on a site.
2.2 EXPOSURE SCENARIOS
The following subsections briefly describe each exposure scenario and present all
equations derived from PATHRAE methodology. More complete explanations and derivations
of the dose equations used in this analysis are contained in the references (EPA87a, ROG85).
2.2.1 Worker - Direct Gamma Exposure
This exposure pathway describes the external gamma radiation dose received by an
employee who works at the site where the diffuse NORM waste is being stored or disposed.
The employee works at the site 2,000 hours per year, spending 80 percent of his time on the
disposal pile. He uses machinery such as a grader or bulldozer which places him about 1
meter above the surface of the pile and provides some shielding from direct gamma radiation.
The equation used to calculate the radiation dose to this worker is:
D - 1 e -*« * -6 * fwex * fsh * DFG
A ^ pwtw J
where
D = Annual dose (mrem/yr)
C = Nuclide concentration in waste (pCi/g)
M = Mass of reference waste pile (g)
A = Plane area of waste pile (m2)
uc = Attenuation coefficient of cover over the waste (m'1)
tc = Thickness of cover over the waste (m)
= Attenuation coefficient of waste material (m"1)
D-2-2
-------
tw = Thickness of waste material (m)
fwex = Fraction of year the worker is exposed = (2000/8766)*0.8 = 0.1825
fgh = Shielding factor = 0.6
DFG = External gamma dose conversion factor (mrem/yr per pCi/m ).
Equation D-l takes into account both the attenuation of gamma radiation by the waste itself
and the attenuation provided by cover material (if any) placed over the waste. The fsh term
accounts for the reduction in exposure due to shielding provided by the grader or bulldozer
used by the worker. Equation D-l does not include dose buildup factors, because experience
with PATHRAE has shown that the use of buildup factors in this formalism overestimates
gamma doses.
Worker - Dust Inhalation
This exposure pathway describes the radiation dose from dust inhaled by the worker
at the diffuse NORM storage or disposal site. The equation used to calculate this dose is:
D = C * fds * dd » Ui * fwex * DFinh (D-2)
where
D = 50-year committed dose equivalent from one year's exposure (mrem)
C = Nuclide concentration in waste (pCi/g)
f^ = Soil dilution factor (dimensionless)
dd = Dust loading in air breathed (g/m3)
Ui = Volume of air breathed in a year (m3/yr)
fwex = Fraction of year the worker is exposed = (2000/8766)*0.8 = 0.1825
DFinh = Inhalation dose conversion factor (mrem/pCi).
D-2-3
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2.2.3 Worker - Indoor Radon Inhalation
This exposure pathway describes the health effects from indoor radon inhalation to
an office worker who works inside a building at the NORM storage or disposal site. Although
any office building would probably be located adjacent to the disposal pile, the assumption
is made that the building is located on top of the pile. This results in a conservatively high
estimate of the risk from indoor radon inhalation. The equation used to calculate the health
effects from inhalation of radon is:
R m CR*pw*E*fde> ^ ^X,DW g-VEDT't,,) , DFR (D.3)
h * Xh
where
R = Risk from radon inhalation (health effects)
CR = Radium concentration in the waste (pCi/g)
pw = Waste density (g/m3)
E = Radon emanation coefficient (dimensionless)
fdex = Fraction of year office worker is exposed = (2000/8766) = 0.23
h = Height of reference room
Xfc = Average air ventilation rate (room air changes per year)
X = Radon decay constant (yr*1)
Dw = Radon diffusion coefficient through waste (m2/yr)
D = Radon diffusion coefficient through building foundation (m /yr)
tb = Thickness of building foundation (m)
DFR = Radon risk coefficient (health effects per pCi/m3 of radon) ,
2.2.4 Onsite individual
This exposure pathway describes the external gamma radiation dose to an individual
who lives on an abandoned NORM waste storage or disposal site. The equation used to
calculate the dose to this individual is:
D-2-4
-------
uwt
DFG
(D-4)
w
Equation D-4 is identical to equation D-l except for the parameter foex which replaces
the product fwex * fsh. The parameter {on is the equivalent exposure fraction for outside
exposure. The value of fTOX = 0.50 takes into account both time spent outdoors directly on the
contaminated ground (assumed to be one-forth of the time) and time spent indoors where the
exposure is reduced due to shielding by the structure.
2.2J5 Onsite Individual - Indoor Radon Inhalation
This exposure pathway describes the health effects from indoor radon inhalation to
an individual who lives in a house located on an abandoned NORM waste storage or disposal
site. The equation used to calculate the health effects from radon inhalation is
cR*pw*E*fiex
R
h*xh
DFR
Equation D-5 is identical to equation D-3 except for the parameter fjex. The parameter
£ is the exposure fraction for indoor exposure and represents the fraction of time that the
individual spends inside the house.
2.2.6 Member of CPG - Direct Gamma Exposure
This exposure pathway describes the external gamma radiation dose received by an
individual who resides near a NORM waste storage or disposal site. The individual is
assumed to be located 100 m from the edge of the disposal pile. The equation used to
calculate the radiation dose to this individual is:
2*A
e
-
uwtw
* e
* foex * DFG
(D-6)
where
D
= Annual dose (mrem/yr)
D-2-5
-------
C = Nuclide concentration in waste (pCi/g)
M = Mass of reference waste pile (g)
2 = Factor to correct for exposure at edge of waste pile
A = Plane area of waste pile (m2)
ue = Attenuation coefficient of cover material (m*1)
te = Thickness of cover material (m)
]i^ = Attenuation coefficient of waste material (m*1)
tw = Thickness of waste material (m)
a = Attenuation coefficient to correct for distance of member of CPG from edge
of waste pile (m*1)
x = Distance of member of CPG from edge of waste pile (100 m)
f = Equivalent exposure fraction for outside exposure (dimensionless)
DFG = External gamma dose conversion factor (mrem/yr per pCi/m )
As is the case for equation D-4, the factor {om in equation D-6 accounts for both the
time spent outdoors and the time spent indoors where shielding reduces the dose rate from
gamma radiation.
2J2.7 Member of CPG - Inhalation of Contaminated Dust
The downwind transport of resuspended particulates (fugitive dusts) containing
radionuclides can result in exposure to a member of the CPG via the inhalation of airborne
particulates and the ingestion of foodstuffs contaminated by dust deposition. Exposure to
direct radiation can also occur as a result of immersion of the individual in the radioactive
dust cloud or from deposited radioactivity. However, the direct radiation dose from fugitive
dusts is only a small fraction of either the inhalation or ingestion dose, and is not calculated.
The inhalation dose from fugitive dusts is described in this subsection and is given by
equation D-7. The ingestion dose is given by equation D-14 described in Subsection 2.2.12.
D-2-6
-------
A Gaussian plume technique is used to model the transport of resuspended material
and to trace the effects of airborne contaminants. The exposed individual is assumed to be
located 100 m downwind from the edge of the NORM storage or disposal site. The equation
used to calculate the dose to a member of the CPG from inhalation of contaminated dust is:
D = 2 qd * « * X' * lit * DFinh (D-7)
ai»Va
where
D = 50-year committed dose equivalent from one year's exposure (mrem)
qj = Atmospheric release rate (pCi/sec)
fw = Fraction of year wind blows in maximum direction (dimensionless)
foai = Equivalent exposure fraction for outdoor exposure (dimensionless)
aj = Atmospheric stability constant (dimensionless)
Va = Average wind speed (m/sec)
X1 = Virtual distance to exposed individual (m)
= 100 +L/2 + 2.5W, where L and W represent, respectively, the length and
width of the disposal site
U{ = Volume of air breathed in a year (m3/yr)
DFinh = Inhalation dose conversion factor (mrem/pCi)
Vd = Deposition velocity for particulates (m/sec).
The atmospheric release rate, q^, for radionuclides in the waste is given by the
equation
qd = Ew * A * C
where
Ew = Resuspension factor (g/m2 - sec)
A = Area of waste site (m2)
C = Waste/soil nuclide concentration (pCi/g).
D-2-7
-------
Using the methodology in NRG Regulatory Guide 3.59 (NRC87), a value for the
resuspension factor can be obtained from the equation
3.156E+07
w
p
8
0.5
where
R8 = The resuspension rate at wind speed S
F8 = The frequency of occurrence of wind speed S
fy = Respirable fraction of resuspended NORM.
The expression in Regulatory Guide 3.59 is modified by the respirable fraction f^.
Regulatory Guide 3.59 tabulates values of R, and Fa for a typical tailings site. Using these
tabulated values, the value of Ew is calculated to be f,. * 1.35E-05 g/m2-sec.
2.2.8 Member CPG - Downwind Exposure to Radon
The risk to an exposed member of the CPG is calculated for downwind exposure to
radon gas exhaled from waste piles containing radium-226. The exposed individual is
assumed to be located 100 m downwind from the edge of the pile. Radon emanation rates
from the waste piles are calculated based on average Ra-226 concentrations in the waste,
radon exhalation rates, and exposed waste pile areas.
Several important factors govern the exhalation rate of radon including mineral form,
material density and porosity, particle size distribution, and moisture content. Changing
meteorological conditions such as atmospheric pressure, surface wind velocity, and differences
between soil and air temperatures can also affect radon emanation rates. For this generic
evaluation, average radon exhalation rates are employed that are believed to be
representative of typical disposal sites where the waste would be disposed. These radon
exhalation rates are also representative of sites where there is no cover material over the
waste.
The equation for calculating the risk to a member of the CPG from downwind exposure
to radon is:
D-2-8
-------
R = 2qR * - ?! - _ * foex * DFR . (D.-8)
ai*Va*X12
where
R = Risk from radon inhalation (health effects)
*
qR = Atmospheric release rate for radon (pCi/sec)
f_ = Fraction of year wind blows in maximum direction (dimensionless)
aj = Atmospheric stability constant (dimensionless)
Va = Average wind speed (m/sec)
X» = Virtual distance to exposed individual (m)
= 100 +L/2 + 2.5W, where L and W represent, respectively, the length and
width of the disposal site
foex = Equivalent exposure fraction for outdoor exposure (dimensionless)
R
DF = Radon risk coefficient (health effects for one year's exposure to 1 pCi/m3
of radon).
The atmospheric release rate for radon is given by the expression
qR = CR * pw * E * A * yX Dw
where
CR = Radium-226 concentration in the waste (pCi/g)
pw = Waste density (g/m3)
E = Radon emanation coefficient (dimensionless)
A = Area of waste site (m2)
X = Radon decay constant (sec*1)
Dw = Radon diffusion coefficient through waste (m2/sec).
This expression is valid for radon diffusion at sites where the thickness of the waste is
greater than about one meter. For agricultural sites where the waste is used as fertilizer,
the above equation must be multiplied by tanh (/X/D * t) , where t is the thickness of the
till layer in meters (0.15 m).
D-2-9
-------
2.2.9 Member of CPG - Exposure to NORM in Building Materials
An estimate is made of exposures to individuals living in a house constructed of
building materials that incorporate NORM wastes. Examples are wallboard containing
phosphogypsum or coal ash. It is assumed that one part of NORM waste is mixed with two
parts of non-contaminated material. Only direct exposure to gamma radiation is considered
in this scenario.
The expression used to calculate the gamma dose to an individual from exposure to
NORM in building materials is a modification of the equation used to calculate the dose to
an individual from a large planar source (EPA87a). The large planar source equation is
modified to take into account multiple exposures from finite sources (the walls and ceiling
of the room). The building characteristics assumed in developing the equation are that the
house contains seven or more rooms and that a fraction of the dose comes from rooms other
that the one in which the person is standing. The average room size is taken to be 20 m ,
and the person is assumed to stand in the center of a room while being exposed.
The expression for the gamma dose to an exposed individual is:
D = C * pw * fiex * fb * 2 * I * (l*2.55e"0'5pi) * DFG (D-9)
2
where
D = Annual dose from gamma radiation (mrem/yr)
C = Nuclide concentration in waste (pCi/g)
pw = Density of wallboard material (g/m3)
f^ = Exposure fraction for indoor exposure (dimensionless)
fb = Fraction of NORM in building materials (dimensionless)
Uj = Gamma attenuation coefficient for building materials (cm2/g)
DFG = External gamma dose conversion factor (mrem/yr per pCi/m2).
The factor of 2 in the equation takes account of the fact that each wall has two sides.
The factor of one-half is a room size factor that takes account of the wall dimensions and the
distance of a person from the walls. The factor of 2.55e " ' Accounts for contributions to the
D-2-10
-------
total dose from radiation from walls in rooms other than the one in which the person is
standing.
2.2.10 Member of CPG - Ingestion of Drinking Water from a Contaminated Well
The ingestion dose is calculated for a member of the CPG assumed to be exposed by
drinking water from a well that becomes contaminated as a result of groundwater transport
of radionuclides from a NORM waste pile. The well is located 100 meters from the waste
pile. The radionuclides move downward through the unsaturated zone to an aquifer beneath
the waste site. In the aquifer, the waste components are transported by advection and
dispersion to a location where the contaminated water is withdrawn from a well.
The equation used to calculate the ingestion dose to an individual who drinks water
from a contaminated well is:
D _ C*M»XL«f0*Ud*DFing (D.10)
qw
where
D = 50-year committed dose equivalent from one year's exposure (mrem)
C = Nuclide concentration in waste (pCi/g)
M = Mass of reference waste pile (g)
XL = Fraction of each nuclide leached from inventory in a year (yr'1)
f = Fraction of nuclide inventory arriving at the well from transport through
*o
the aquifer (dimensionless)
Ud = Annual volume of water consumed by an individual (m /yr)
qw = Dilution volume for the well (m3/yr)
DFing = Ingestion dose conversion factor (mrem/pCi)
The expression used to calculate the fraction of each nuclide leached from inventory
in a year, XL, is:
D-2-11
-------
Kd*pw*tw*Kg
where
I = Annual water infiltration rate through the waste (m/yr)
Kd = Equilibrium distribution coefficient of 'the waste/soil matrix (m3/kg)
(Assumed to be the same as the Kd for the aquifer.)
pw = Density of the waste/soil matrix (kg/m3)
t^, = Thickness of the waste (m)
= Saturated hydraulic conductivity of the waste/soil matrix (m/yr).
The term I/Kg is the fraction of the year the waste is in contact with water. This
correction for unsaturated leaching is contained in the EPA's PRESTO model (EPASTb).
The annual water infiltration rate is taken to be one-half the annual rainfall. The
density of the waste/soil matrix is assumed to be the same as the density of the aquifer.
The expression used to calculate f0, the fraction of the nuclide inventory arriving at
the well from transport through the aquifer is:
f
0
L*R*XL
where
Vw = Horizontal velocity of aquifer (m/yr)
L = Length of waste site parallel to aquifer flow (m)
R = Retardation factor = 1 + (pa/p) * Kd
pa = Aquifer density (kg/m3)
p = Aquifer porosity (dimensionless)
Kd = Equilibrium distribution coefficient in the aquifer (m3/kg).
The dilution volume for the well, qw, is assumed to be the annual rainfall multiplied
by the area of the waste pile.
D-2-12
-------
2JJ.11 Member of CPG - Ingestion of Food ;tuffs Contaminated by Well Water
The ingestion dose is also calculated for E member of the CPG assumed to be exposed
by eating foodstuffs irrigated with well water :hat becomes contaminated as a result of
groundwater transport of radionuclides from a NORM waste pile. The equation used to
calculate this ingestion dose is:
XL«f *Uc*DFing
Equation D-13 is identical to equation D- D except for the factor Uc which replaces the
factor Ud. The factor Uc (m3/yr) is the annual eqi ivalent foodstuff consumption uptake factor
for an individual. It is given by
Uc = Uv - Ud
where Uw is the annual equivalent water uptal 2 factor for an individual.
2.2.12 Member of CPG - Ingestion of Foods uffs Contaminated bv Dust Deposition
This exposure pathway describes the ngestion dose to an individual who eats
foodstuffs contaminated by fallout from fugitive lusts. As described in Subsection 2.2.7, the
downwind transport of resuspended particulatei contaminated with radionuclides can cause
exposure to a member of the CPG through t .e inhalation of the dust particles or the
ingestion of crops grown in soils contaminated v ith radioactive fallout. The inhalation dose
is calculated by equation D-7. The ingestion dc >e is calculated by:
where
D =50 year committed dose equi\ dent for one year's exposure (mrem)
qd = Atmospheric release rate (pC 'sec)
f^ = Fraction of year wind blows i i maximum direction (dimensionless)
D-2-1 i
-------
a^ = Atmospheric stability constant (dimensionless)
Va = Average wind speed (zn/sec)
Xj = Virtual distance to exposed individual (nv)
= 100 +L/2 + 2.5W, where L and W represent, respectively, the length and
width of the disposal site
Vd = Deposition velocity for particulates (m/sec).
^dep = Deposition time (sec)
Uf = Food uptake factor (kg/yr)
Xroot = Root uptake factor (kg/m2)
DFin_ = Ingestion dose conversion factor (mrem/pCi)
Vd/(Va * a{)
The atmospheric release rate, q^, is calculated as explained in Subsection 2.2.7. The
root uptake factor, X,.^, is the product of the average root depth and the soil density.
2.2.13 Member of CPG - Ingestion of Foodstuffs Grown on Repeatedly Fertilized
Soil
This exposure pathway describes the ingestion dose to an individual who eats
foodstuffs grown in soil that is repeatedly fertilized with phosphate fertilizer or water
treatment sludge. Fertilizers are spread over agricultural fields and diluted by mixing with
the soil. Hence the incremental radionuclide concentrations in the soil are much lower than
the radionuclide concentrations in the fertilizer itself. Over time, as fertilizers continue to
be applied, the radionuclide concentrations in the soil are expected to increase until
equilibrium is reached with competing mechanisms that remove fertilizers, and their
radioactive constituents, from the soils. These removal mechanisms include plant uptake,
leaching by infiltration of surface water, and wind and water erosion. The number of years
required for radionuclide concentrations in repeatedly fertilized soils to reach equilibrium is
not known and ran only be estimated with considerable uncertainty. For this ingestion dose
calculation, a time period of 20 years of repeated fertilizer application is assumed.
D-2-14
-------
Radionuclide concentrations are assumed to continue to increase during this period, and no
credit is taken for depletion mechanisms that might remove radionuclides from the soil.
The equation used to calculate the ingestion dose to a person who eats foodstuffs
grown in repeatedly fertilized soil is:
D = 103 * C * Uf « DFing
where
D = 50-year committed dose equivalent from one year's exposure (mrem)
C = Nuclide concentration in waste (pCi/g)
103 = Conversion factor to convert from pCi/g to pCi/kg
Uf = Food uptake factor (kg/yr)
DFing = Ingestion dose conversion factor (mrem/pCi)
2.2.14 General Population - Downwind Exposure to Resusoended Participates
This exposure pathway describes the dose to the general population in the vicinity of
the disposal site from the downwind transport of resuspended particulates (fugitive dusts)
containing radionuclides. Doses to the exposed population can result from the inhalation of
airborne particulates, ingestion of crops and produce contaminated with deposited fugitive
dusts, and direct radiation from deposited radioactivity. The exposed population is assumed
to reside within a radius of 8x104 meters (50 miles) of the NORM waste storage or disposal
site.
The equation used to calculate the population dose from this exposure pathway is:
CD
*PD*
(D-16)
where
D-2-15
-------
CD = Population dose (person-mrem)
PD = Population density (persons/m2)
qd = Atmospheric release rate (pCi/sec)
aj = Atmospheric stability constant (dimensionless)
Va = Average wind speed (m/sec)
Xj = Minimum distance to exposed individual (m)
= 100 +L/2 + 2.5W
Xg = Maximum distance of integral used to evaluate exposed population (m)
U{ = Annual breathing rate (m3/yr)
Vd = Deposition velocity for particulates (m/sec).
ldep = Deposition time (sec)
Uf = Food uptake factor (kg/yr)
X^ot = Root uptake factor (kg/m2)
DFinh = Inhalation dose conversion factor (mrem/pCi)
DFin_ = Ingestion dose conversion factor (mrem/pCi)
DFG = External gamma dose conversion factor (mrem/yr per pCi/m2).
b = >/27JT* Vd/(Va*ai)
The atmospheric release rate, q^, for radionuclides is calculated the same way for the
population dose from, downwind exposure as for the individual dose from downwind exposure
(see Subsection 2.2.7).
2.2.15 General Population - Downwind Exposure to Radon
The risk to a representative population in the vicinity of the disposal site is calculated
for downwind exposure to radon gas exhaled from NORM waste piles containing radium-226.
As is the case for the calculation of the radon risk to an individual member of the CPG
(Subsection 2.2.8), radon emanation rates from the waste piles are calculated based on
D-2-16
-------
average Ra-226 concentrations i the waste, representative radon exhalation rates, and
exposed pile areas for represent .live waste piles. The exposed population is assumed to
reside within a 8xl04 m (50 mi) adius of the waste pile.
The equation used to calc late the population risk from downwind exposure to radon
gas is:
PR
f] * _SL- * Infel
>|r Va*ai |XXJ
* PD * DFR
(D-17)
where
PR = Population ris. from radon inhalation (health effects)
qR = Atmospheric n lease rate for radon (pCi/sec)
Va = Average wind peed (m/sec)
3{ = Atmospheric s ability constant (dimensionless)
XQ = Maximum dist mce of integral used to evaluate exposed population (m)
X, = Minimum dist nee to exposed individual (m)
= 100 +L/2 + 2.5 V
PD = Population dei sity (persons/m2)
DFR = Radon risk CCK Hcient (health effects per pCi/m3 of radon).
The atmospheric release r te for radon, qR, is calculated as shown in Subsection 2.2.8
which describes the dose to an ii dividual from downwind exposure to radon gas.
2.2.16 General Population - Ingestion of River Water Contaminated via the
Groundwater Patlvx ay
This exposure pathway dc .cribes the population dose from the use of river water that
has become contaminated by thi groundwater migration of radionuclides from the NORM
waste storage or disposal site. 1 he equation used to calculate the population dose for this
exposure scenario is:
D-2-17
-------
CD = C*M*XL*f0*Uw*EP*DFine
qr
where
CD = 50-year committed dose to the population from o ie year of exposure
(person-mrem)
C = Nuclide concentration in waste (pCi/g)
M = Mass of reference waste pile (g)
XL = Fraction of each radionuclide leached from inventor in a year (yr"1)
f0 = Fraction of nuclide inventory arriving at the river fr< 01 transport through
the aquifer (dimensionless)
Uw = Annual water equivalent uptake factor for an indivi lual (m /yr)
EP = Exposed population (persons)
qr = Flow rate of the river (m3/yr)
DFin_ = Ingestion dose conversion factor (mrem/pCi)
The factors XL and f0 are calculated as described in Subsection 2.2.10.
The exposed population is estimated by multiplying the popi ation density by an
assumed area in which people live who would use the river water f r drinking or would
consume foodstuffs contaminated by agricultural use of the water. This "use area" is
assumed to be approximately 1,000 mi2.
2.2.17 General Population - Ingestion of River Water Contami lated by Surface
Runoff
This exposure pathway describes the population dose from tl a use of river water
contaminated through surface runoff of rainwater that transports radio .uclides leached from
a NORM waste pile. The equation used to calculate the population c >se for this exposure
scenario is:
D-2-18
-------
EP , DF
w ing
where
CD = 50-year committed dose to the population from one year of exposure
(person-mrem)
C = Nuclide concentration in waste (pCi/g)
pw = Waste density (g/m3)
fdt = Dilution factor for surface water transport of waste (dimensionless)
I = Annual water infiltration rate through the waste (m/yr)
rf = Runoff fraction (dimensionless)
A = Area of waste site (m2)
R = Retardation factor (dimensionless)
qr = Flow rate of the river (m3/yr)
Uw = Annual water equivalent uptake factor for an individual (m3/yr)
EP = Exposed population (persons)
DFin_ = Ingestion dose conversion factor (mrem/pCi)
The annual water infiltration rate through the waste, I, is assumed to be one-half the
rainfall at the site. The retardation factor, R, for surface runoff is assumed to be the
same as it is for the aquifer (i.e., groundwater) transport of radionuclides. In the aquifer this
retardation factor is given by:
R = 1 + (pa / p) * Kd
where
pa = Aquifer density (kg/m3)
p = Aquifer porosity (dimensionless)
Kd = Equilibrium distribution coefficient (m3/kg).
D-2-19
-------
2.2.18 General Population - Ingestion of Foodstuffs Grown on Repeatedly
Fertilized Soil
This exposure pathway describes the ingestion dose to an exposed population from
eating foodstuffs grown in repeatedly fertilized soil. This scenario is similar to that described
«
in Subsection 2.2.13 for the ingestion dose to an individual who eats food grown in soil that
is repeatedly fertilized for a period of 20 years. The equation for calculating the ingestion
dose to the exposed population is
CD = 103 * C * Uf * DFing * POP (°-21)
where
CD = 50-year committed dose to the exposed population from one year of
exposure (person-mrem)
POP = The population eating food grown on repeatedly fertilized soil (persons).
The other parameters in D-21 have the same meaning as in equation D-15.
The exposed population is obtained by estimating how many persons would obtain
their annual average vegetable requirement from agricultural fields fertilized by phosphate
fertilizer. The equation used to calculate the exposed population is
(POP) = A
IG
where
A = Plane area of fertilized field (m2)
Ie = Areal requirement for an individual for vegetables consumed annually
(m2/person)
The individual areal requirement, Ic, is 292 m2/person as determined from the
equation:
, _ Individual Consumption Rated 90 kg/yr)
Vegetable ProductionDensity (0.65 kg/m 2-yr)
Values for the individual consumption rate and the vegetable production density are taken
from the EPA's Background Information Document (EPA88a).
D-2-20
-------
2.3 INPUT PARAM 3TERS
Values of the va ious input parameters used with'the equations >f Section 2.2 to
evaluate individual and population doses from the storage,and disposal < f diffuse NORM
wastes are presented in his section. Input parameters include generic par imeters that are
assumed to be the same for all NORM sectors, parameters that are site a id NORM-sector
specific, and parameter! that are nuclide specific.
Values of generic oarameters that are assumed to have the same vr ue regardless of
waste type or site locati a are shown in Table D.2-1.
Values of site-spt :ific parameters are shown in Tables D.2-2 and D. :-3. Site specific
parameters include reft ence site dimensions and radionuclide concentr tions which are
shown in Table D.2-2, & id equilibrium distribution coefficients (Kd) and c her site-specific
parameters shown in Ti ale D.2-3. The rationale for the values used for t lese site-specific
parameters is presentee in Chapter B, in part, and in this chapter.
All of the dose ai 1 health risk calculations for fertilized agricultur: I sites are based
on radionuclide concent ations resulting from repeated applications of ft tilizer during a
20-year period. As pr viously described in Section 2.2.13, fertilizers ire spread over
agricultural fields and liluted by mixing with the soil. For repeated pplications, the
radionuclide concentrate ns in the soil increase until an equilibrium is rea> ned between the
rate at which fertilizer 5 added to the soil and the rate at which it is r moved by plant
uptake, leaching, wind ; id water erosion, and other removal mechanisms The number of
years required for radio uclide concentrations to reach equilibrium in rep atedly fertilized
soils is difficult to estim .te with any degree of certainty, and may be nucl ie dependent.
All of the indivic lal and population exposure scenarios involving t ie application of
fertilizer to agricultural ields are based on radionuclide concentrations in he soil resulting
from 20 years of fertili er application. The radionuclide concentrations are assumed to
increase linearly during this period, and no credit is taken for depletion : lechanisms that
could remove radionucli es. For phosphate fertilizers, the application rate '.s assumed to be
37 kg per hectare, applit d annually (see Section 3.4.1). For water treatmej t sludge used as
D-2-21
-------
Table D.2-1. Generic input parameters for diffuse NORM risk assessment.
Symbol
a
Parameter
drt
EP
fdex
h
Ic
rf
T
Total amount of fertilizer applied per year
Attenuation coefficient for distance of average CFG
from waste pile
Atmospheric stability constant (50% C stability,
50% D stability)
Radon diffusion coefficient through concrete
Radon diffusion coefficient through waste
. humid site
- dry site
Dust loading in air breathed
Root depth in fertilized soil
Exposed population using river
Annual rate of fertilizer application
Fraction of NORM in building materials
Fraction of year wind blows in maximum direction
Soil dilution factor (fertilizer)
Dilution factor for surface water transport of waste
Shielding factor for worker exposure
Fraction of year office worker is exposed
Exposure fraction for indoor exposure
Equivalent exposure fraction for outside exposure
Fraction of year waste pile worker is exposed
Height of reference room
Area! requirement for vegetables consumed by an
individual
Aquifer porosity
Flow rate of river
Surface water runoff fraction
Years of fertilizer application for repeatedly
fertilized soils
Thickness of building floor (cement)
Units
g/yr
m
'1
Value
4.8E+12
5.0E-3
7.0E-2
m2/yr
m2/yr
g/m3
m
persons
g/m2-yr
--
-
~
~
~
m
m2
m3/yr
~
yr
1.6E+1
2.2E+1
6.3E+1
5.0E-4
l.OE+0
3.3E+3
3.7E+0
3.3E-1
9.3E-2
2.3E-3
7.0E-1
6.0E-1
2.3E-1
7.5E-1
5.0E-1
1.8E-1
2.3E+0
2.9E+2
3.3E-1
l.OE+8
5.0E-1
2.0E+1
m
1.5E-1
D-2-22
-------
Table D.2-1. Continued.
Symbol
tdep
ud
u,
va
vd
vw
^root
*2
X
X
*h
uc
V4
Uw
Pa
Parameter
Deposition time for particulates
Volume of drinking water coT1*?"1^ annually hy
an individual
Volume of air breathed in a year
Average wind speed
Deposition velocity for particulates
Horizontal velocity of aquifer
Root uptake factor
Maximum distance of integral used to evaluate
exposed population
Distance of well and of average CFG from edge of
waste pile
Radon decay constant
Room air changes per year
Gamma linear attenuation coefficient for cover
material
Gamma mass attenuation coefficient for building
material (wallboard)
Gamma linear attenuation coefficient for waste
material
Aquifer density
Units
sec
m3/yr
m3/yr
m/sec
m/sec
m/yr
kg/m2
m
m
yr'1
yr'1
m'1
cm2/g
m'1
g/cm3
Value
6.3E+8
3.7E-1
8.0E+3
4.5E+0
l.OE-3
2.0E+1
7.0E+2
8.0E+4
l.OE+2
6.6E+1
1.8E+4
1.5E+1
l.OE-1
1.5E+1
1.8E+0
D-2-23
-------
Table D.2-2. Reference dlapoaal pUe parameters and radionncllde concentratlona for dlfluae NORM risk
I
Parameter
Unite
Uranium
Overburden
Phoaphato
Waste
Texaa
6.6E+07
Honda
6.0E+07
m
m
m
m
m8
1200
1200
20
None
1.4E+06
1760
1760
7
None
3.0E+06
1200
1200
0.16
None
1.4E+06
600
600
6.0
None
2.6E«06
1200
1200
0.16
None
1.4E*06
400
400
2
OJO
1.6E+06
700
700
30
None
4.9E+06
400
400
4A
None
1.6E+06
320
320
4
0.16
l.OE+06
I i.,. -ri>.r
Pile
Waste Mass
Reference Pile MT
Reference Disposal Pile
Length
Width
Thickness
Cover
Surface Ana
No. of Reference Piles 1.4E+01 1.6E+01
lnU.S.
Average Waste Density g/on* 20 2.36
Nuclide Concentration
Po-210 pCi/g 16.6 26.4
Pb-210 pCi/g 16.6 26.4
Ra-226 pCl/g 23.7 33.0
Th-228 pCi/g 1.0 0.27
Ra-228 pCi/g 1.0 0.27
Th-230 pCi/g 23.7 13.0
Th-232 pCi/g 1.0 0.27
U-234 pCi/g 23.7 62
U-238 pCi/g 23.7 60
U-236 pCi/g 1.2 0.3
Phcwphate
Fertilizer
Illinois
3.4E«06
CoalAah
Northeasl
1JE«06
Water
Treatment
Sludge -
Fertilizer
Illinois
3.4E+06
Water
Treatment
Sludge -
LandBII
Illinois
6.1E+06
Mineral
Prooeaalng
Waste
Arizona
3.0E+07
OUAGae
Scale/Sludge
Texas
1.3E*06
O«o thermal
Energy Waste
California
7.4E+05
9.4E+06 1.3E«03 4.4E+02* 2JE«02b
1.6 13 1.6
6.7
6.7
8.2
1.1
1.1
63.0
1.0
66.3
66.3
2.8
7.0
6.8
3.7
3.2
1.8
23
2.1
33
3.3
0.18
10.0
10.0
16.0
0.2
20.0
0.2
0.2
4.0
4.0
0.03
10.0
10.0
16.0
0.2
20.0
0.2
02
4.0
4.0
003
6.7E+02
2.0
26.0
26.0
36.0
10.0
100
36.0
10.0
36.0
36.0
1.8
l.OE+01
1.8
166.0
166.0
166.0
66.0
660
2.0E+00
110.0
110.0
160.0
30.0
110.0
a Assumes that all of the water treatment sludge generated dunng the 20-year reference period is used as fertilizer.
b Assumes that all of the water treatment sludge generated during the 20-year reference period is disposed of at landfills.
-------
Table D.2-3. Site-specific Input parameters for diffuse NORM risk assessment.
p
£
Wl
Parameter Symbol
Distribution Coeflicents
Po-210 Kd
Pb-210 K,,
Ra-226 Kj
Th-228 Kj
Ra-228 K,,
Th-230 Kj
Th-232 Kj
U-234 K,,
U-238 Kj
U-235 Kj
Waste Porosity
Respirable Fraction f.
Radon Emanation E
Coefficient
Annual Rainfall at Site
Saturated Hydraulic K,
Conductivity
Water Percolation Rate I
Through Waste
Dilution Volume for Well qw
Population Density for PD
Atmospheric Pathways
per Site
Population Using River EP
Water per Site
Virtual Distance to X,
Unite
m'/kg
ms/kg
m'/kg
ma/kg
m3/kg
ms/kg
m3/kg
m3/kg
m'/kg
m'/kg
cm/yr
m/yr
m/yr
m3/yr
persons
per mi2
persons
m
Uranium
Overburden
0.050
0.090
0.045
150
0.045
15.0
15.0
0045
0045
0045
0.40
050
0.30
72.5
3.15E+04
036
l.OE+06
64
70,000
3700
Phosphate
Waste
0.60
0.90
0.45
1500
0.45
150.0
150.0
045
0.45
0.45
0.25
0.20
0.20
124.5
3.15E+02
0.62
3.7E+06
216
235,000
5350
Phosphate
Fertiliser
0.50
0.90
045
150.0
0.45
1500
150.0
0.45
0.45
045
0.25
0.50
030
90.7
3.15E+04
0.45
1.3E+06
210
230,000
3700
Coal Ash
0.10
0.10
0.075
30
0.075
3.0
3.0
0050
0.050
0.050
03
0.1
0.04
110.0
1.00 E+ 02
055
2.8E+05
780
850,000
1600
Water
Treatment
Sludge -
Fertilizer
0.50
0.90
0.45
160.0
0.45
150.0
150.0
0.45
0.45
0.45
0.35
0.7
0.40
90.7
3.15E+04
0.45
1.1E+06
210
230,000
3700
Water
Treatment
Sludge -
Landfill
0.50
0.90
0.45
1500
0.45
160.0
150.0
0.45
0.45
0.45
0.35
0.7
0.40
90.7
3.16E+04
0.45
1.5E+05
210
230,000
,
1300
Mineral
Processing
Waste
0.050
0.090
0.045
15.0
0.045
15.0
15.0
0.045
0.045
0.045
0.40
0.50
0.30
283
3.15E+04
0.14
1.4E+05
46
50,000
2200
Oil & Gas
Scale/Sludge
0.10
0.10
2.5
2.5
2.5
0.40
0.05
0.10
61.0
3.0E+02
*
0.26
8.2E+04
64
70,000
1300
Geothermal
Energy Waste
0.050
0.090
0.045
15.0
0.045
0.40
0.05
0.26
25.0
3.0E+03
0.12
2.5E+04
181
200,000
1060
Exposed Individual
-------
fertilizer, the application rate is assumed to be 10,000 kg per hectare (4.5 tons per acre),
applied every other year (see Section 6.5.1). The fertilizer is assumed to be mixed with the
top 0.15 m of soil. The radionuclide concentrations for phosphate fertilizer and water
treatment sludge shown in Table D.2-2 are adjusted for fertilizer application rates and soil
mixing ratios to obtain the radionuclide concentrations in repeatedly fertilized soil used in
the risk calculations.
The water percolation rate through the waste, I, shown in Table D.2-3 is assumed to
be equal to one-half the annual average rainfall at the waste site. The dilution volume for
the well, q^ is assumed to equal the rainfall rate multiplied by the pile area.
Population densities used in evaluating total population health effects for downwind
exposure to resuspended particulates are the average population densities for the state listed
under each NORM waste sector in Table D.2-3. Exposed populations used in evaluating total
population health effects from ingestion of contaminated river water are also based on the
average population densities in Table D.2-3, and are estimated as described in Subsection
2.2.16.
Nuclide-sperific parameters used in this analysis include equilibrium distribution
coefficients (1^), leach rates, dose conversion factors, and equivalent food and water uptake
factors. Values for equilibrium distribution coefficients are site specific and are shown in
Table D.2-3. Values for leach rates are calculated using Equation D-ll of Section 2.2.10.
Equation D-ll is derived from the leaching model used by the U.S. Environmental Protection
Agency in the PRESTO-EPA-POP environmental transport risk assessment code (EPASTb).
The dose and risk conversion factors used in this analysis are shown in Table D.2-4.
Dose conversion factors for ingestion and inhalation are from the EPA's Federal Guidance
Report No. 11, which provides guidance for the control of occupational exposures to radiation
(EPA88b). Inhalation and ingestion dose conversion factors represent 50-year committed dose
equivalents from one year of intake. Dose conversion factors for direct exposure to gamma
radiation are from guidance for modifying PRESTO-EPA-CPG to reflect major recent changes
in the EPA's dose calculation methodology. They represent effective whole body dose
equivalents from external exposure during one year.
D-2-26
-------
Table D.2-4. Dose and risk conversion factors.
I. Dose Conversion Factors
Direct Gamma
Nuclide
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
a 50-year committed
Inhalation
(mrem/tlCi)a
9.4E-03
1.4E-02
8.6E-03
3.4E-01
4.8E-03
3.3E-01
1.6E+00
1.3E-01
1.2E-01
1.2E-01
dose equivalent from
Ingestion DF
(mrem/oCi)a
1.9E-03
5.4E-03
1.3E-03
4.0E-04
1.4E-03
5.5E-04
2.7E-03
2.8E-04
2.5E-04
2.7E-04
(mrem/yr
per t>Ci/m )
8.55E-10
2.91E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41E-08
1.67E-05
one year of intake (uptake).
IL Risk Conversion Factors.1*
Nuclide
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
Inhalation
(Risk per pCi
inhaled)
1.5E-09
2.2E-09
1.3E-09
5.3E-08
7.4E-10
5.1E-08
2.5E-07
2.0E-08
1.9E-08
1.9E-08
Ingestion DF
(Risk per pCi
invested)
2.9E-10
8.4E-10
2.0E-10
6.2E-11
2.2E-10
8.5E-11
4.2E-10
4.3E-11
3.9E-11
4.2E-11
Direct Gamma
(Risk per pCi/m2)
3.3E-16
1.1E-13
6.5E-11
1.3E-10
3.5E-11
3.5E-14
2.6E-14
3.1E-14
2.5E-14
6.5E-12
b 70-year lifetime risk of a fatal cancer from one year of exposure.
D-2-27
-------
Table D.2-4. Continued.
IL Radon Risk Conversion Factors.6
Rn-222 and Inhalation Risk
Daughters per pCi/m3
Indoor Exposure 4.9E-06
Outdoor Exposure 4.9E-07
c ' 0-year lifetime risk of fatal cancer of one year of exposure to Rn-222 and Rn-222
< aughters.
D-2-28
-------
Risk conversion factors in Table D.2-4 are based on the radiation risk factors in Table
6-27 of Volume I of the EPA's "Environmental Impact Statement for NESHAPS
Radionuclides" (EPA89a). They represent lifetime (i.e., 70 year) risks of fatal cancers from
one year of exposure. A quality factor of 1 has been used to convert from rads to rems for
low-LET (i.e, gamma) radiation, and a quality factor of 20 has been used to convert from rads
to rems for high-LET (i.e., alpha) radiation.
Equivalent uptake factors for food and water are shown in Table D.2-5. These factors
are calculated by the PATHRAE-EPA performance assessment code (EPA87a) using PRESTO
dose assessment methodology. The equivalent uptake factors quantify, on a nuclide-specific
basis, the annual amount of nuclide uptake by an individual from all potential ingestion
sources. For ingestion pathways involving the use of contaminated water, the water
equivalent uptake factor is the total equivalent drinking water consumption (m /yr) that
would give the same annual nuclide uptake as would occur from the consumption of
contaminated vegetation, meat, milk, seafood, and actual water consumption. For pathways
involving food grown in contaminated soil, the food equivalent uptake factor is the equivalent
amount of soil material (kg/yr) an individual would have to directly consume in order to
ingest the same amount of a particular nuclide that is ingested by eating contaminated foods.
Since water-to-soil and soil-to-plant transfer factors, and other related factors may be nuclide
dependent, the equivalent water and food uptake factors are nuclide dependent.
D-2-29
-------
Table D.2-5. Equivalent uptake factors.8
Nuclide
Food Uptake Factor UF
(ke/yr)
Water Uptake Factor Uw
(m3/yr)
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.31E-02
1.31E-02
1.31E-02
1J29E-02
1J29E-02
1.31E-02
1.29E-02
2.21E-02
2.21E-02
2.21E-02
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
a See text for details.
D-2-30
-------
D.3 RISK ASSESSMENT RESULTS
The risk assessment equations of Section 2.2 were use,d with the input data of Section
2.3 to evaluate doses and health effects to individuals and populations from the storage or
disposal of diffuse NORM wastes. The results of these risk calculations are presented in this
section.
3.1 WORKER DOSES AND RISKS
Table D.3-1 gives the doses and risks to workers at the storage or disposal sites from
the direct gamma exposure and dust inhalation pathways. As explained in subsection 2.2.1,
the worker is assumed to spend 80 percent of each working day on the disposal pile and to
use machinery such as a grader or bulldozer. Direct gamma exposures are estimated to
result in the highest worker doses and risks - typically about three orders of magnitude
larger than the doses and risks from dust inhalation. The direct gamma exposure doses are
estimated to range from 6.5E+2 mrem/yr for direct exposure to oil and gas scale/sludge to
0.006 mrem/yr for direct exposure to radiation from a field repeatedly fertilized with
phosphate fertilizer. Estimated 70-year lifetime risks of fatal cancer from one year of
exposure range from 2.5E-04 for exposure from oil and gas scale/sludge to 2.4E-09 for
exposure from a repeatedly fertilized field.
Estimated health effects from radon inhalation to office workers who work inside
buildings at the NORM storage and disposal sites are given in Table D.3-2. Estimated
70-year lifetime risks of fatal cancer from one year of exposure for these office workers range
from 9.3E-02 at the geothermal waste site to 1.2E-04 at the landfill site for water treatment
sludge. Health effects to office workers from indoor radon inhalation dominate the worker
risks at the NORM waste sites. In general, the cancer risks from radon inhalation to persons
working in offices located on top of waste piles are estimated to be about three orders of
magnitude larger than the cancer risks from gamma exposure to persons working on the
NORM waste piles.
D-3-1
-------
Table D.3-1. Worker doses and health effects from storage or disposal of diffuse NORM.
Exposure Scenario
Direct Gamma Exposure
Dose (mrem/yr)*
Health Effects"
Dust Inhalation
Dose (mrem)b
Health Effects*
Uranium
Overburden
6.6E+01
2.5E-05
2.8E-02
4.3E-09
Phosphate
Waste
9.9E+01
SJE-05
1.2E-02
1.9E-09
Phosphate
Fertlifater
6.2E-03
2.4E-09
1.7E-05
2.7E-12
Coal
Ash
1.6E+01
6.3E-06
1.1E-02
1.6E-09
Water
Treatment
Sludge -
Fertilizer
2.3E+00
8.8E-07
1.3E-04
2.0E-11
Water
Treatment
Sludge -
Landfill
8.0E-01
3.1E-07
4.8E-05
7.6E-12
Mineral
Processing
Waste
1.6E+02
6.9E-05
6.9E-02
1.1E-08
Oil A Gas
Scale/Sludge
6.6E+02
2.5E-04
4.0E-02
6.3E-09
Geothermal
Waste
6.7E+01
2.6E-06
2.5E-02
3.8E-09
I
The annual whole body effective dose equivalent (mrenVyr).
The 60-year committed dose equivalent (mrem) from one year of intake.
The 70-year lifetime risk of a fatal cancer from one year of exposure.
-------
Table D.3-2. Risks from radon Inhalation.
Water Water
Treatment Treatment Mineral
Exposure Scenario
Office Worker
Health Effects"
Onsite Individual
Health Effects"
Member of CPG
Health Effects"
Population
Health Effects"
Uranium
Overburden
1.8E-02
6.0E-02
4.3E-07
3.8E-03
Phosphate
Waste
1.2E-02
3.9E-02
2.8E-07
1.6E-02
Phosphate
FertUUer
3.0E-06
B.4E-12
1.6E-07
Coal
Ash
1.4E-04
4.6E-04
3.0E-09
7.8E-05
Sludge -
FertUUer
l.OE-03
1.6E-09
4.7E-05
Sludge -
Undfill
1.2E-04
3.8E-04
2.6E-09
1.2e-05
Processing
Waste
2.7E-02
8.9E-02
6.3E-07
1.7e-03
QUA Gas
Scale/Sludge
2.1E-02
7.0E-02
4.6E-07
6.8C-04
Geothermal
Waste
9.3E-02
3.1E-01
1.9E-06
5.5E-03
a The 70-year lifetime risk of a fatal cancer from one year of exposure. Health effects to the office worker and the onsite individual are for indoor exposure. Health effects
to the member of the CPG located 100 m downwind of the site are for outdoor exposure.
b The number of excess fatal cancers expected int he exposed population as a result of one year of exposure. The number of persons in the exposed population is given in
Table D.2-3.
-------
3.2 DOSES AND RISKS TO MEMBERS OF THE CRITICAL PQPTTLATIQN GROUP
(CPG)
Estimated doses and risks to members of the CPG are shown in Table D.3-2 for radon
inhalation scenarios and in Table D.3-3 for all other exposure scenarios that were evaluated.
f
The CPG is assumed to be located 100 meters away from the waste site. The cancer risks
from indoor radon inhalation dominate the CPG risk calculations. Estimated 70-year lifetime
risks of fatal cancer from one year of exposure to persons living in houses located on
abandoned NORM waste storage or disposal sites range from 3.1E-01 at the geothermal
waste site to 3.0E-06 on a repeatedly fertilized field (see Table D.3-2).
For exposure scenarios other than radon inhalation (Table D.3-3), the direct gamma
exposure pathways dominate. The highest exposures, of the order of l.OE+04 mrem/yr, and
highest risks, of the order of 5.0E-03 lifetime risk of fatal cancer from one year of exposure,
result from the use of phosphate and mineral processing wastes in wallboard for home
construction. Direct gamma exposures to persons who reside at abandoned waste sites are
estimated to range from about 3.0E+03 mrem/yr at the oil and gas scale/sludge site to about
0.03 mrem/yr on a repeatedly fertilized field. Estimated 70-year lifetime risks of fatal cancer
from one year of exposure range from 1.2E-04 at the oil and gas scale/sludge site to 1.1E-08
at the repeatedly fertilized field. Doses and health effects from consumption of contaminated
foodstuffs are estimated to be very small compared to doses and health effects from direct
gamma exposure.
3.3 POPULATION DOSES AND RISKS
Estimated population risks from downwind exposure to radon are given in Table D.3-2.
The collective doses and risks from other exposure pathways that were evaluated are given
in Table D.3-4.
The largest collective doses and risks are calculated for the exposure pathway
involving the use of river water contaminated by surface runoff. For this exposure pathway
the estimated collective doses range from 1.1E+05 person-mrem for the uranium overburden
D-3-4
-------
Table D.S-3. Individual doses and health effects from storage or disposal of diffuse NORM.
Exposure Scenario
Onsite - Direct Gamma
Dose (mrem/yr)"
Health Effects'1
CPG Direct Gamma
Dose (mrem/yr)*
Health Effects'
CPG Dust Inhalation
Dose (mremr
Health Effects'*
NORM in Building
Materials
Dose (mrem/yr)*
Health Effects'1
Drink Contaminated Well
Water
Dose (mrem)c
Health Effects'1
Foodstuffs Contaminated
by Well Water
Dose (mrera)*
Health Effects'1
Foodstuffs Contaminated
by Dust Deposition
Dose (mrem)c .
Health Effects'1
Foodstuffs from Fertilized
Soil
Dose (mrem)c
Health Effects'1
Uranium
Overburden
2.9E+02
1.1E-04
8.9E+01
3.6E-05
2.7E-02
4.2E-09
-
5.7E-03
8.7E-10
8.6E-03
1.3E-09
4.6E-07
7.1E-14
Phosphate
Waste
4.6E+02
1.8E-04
1.4E+02
6.3E-05
4.9E-03
7.6E-10
1.1E+04
4.4E-03
1.3E-01
2.1E-08
2.0E-01
3.2E-08
2.6E-07
3.8E-14
-
Phosphate
Fertilizer
28E-02
1.1E-08
8.6E-03
3.3E-09
1.7E-05
2.6E-12
-
1.2E-07
1.9E-14
1.8E-07
2.8E-14
l.OE-10
1.6E-17
6.6E-04
8.5E-11
Coal
Ash
7.4E+01
2.9E-05
2.3E+01
8.8E-06
2.0E-03
3.0E-10
1.9E+03
7.3E-04
6.2E-01
9.6E-08
9.6E-01
1.6E-07
3.2E-08
4.9E-15
-
Water
Treatment
Sludge -
Fertilizer
l.OE+01
4.0E-06
3.1E+00
1.2E-06
l.BE-04
2.3E-11
-
2.6E-05
4.0E-12
4.0E-05
6.2E-12
1.6E-08
2.3E-15
6.6E-02
l.OE-08
Water
Treatment
Sludge -
Landfill
3.6E+00
1.4E-06
1.1E+00
4.3E-07
6.1E-05
9.6E-12
-
8.0E-06
1.2E-12
1.2E-06
1.9E-12
6.9E-09
9.1E-16
-
Mineral
Processing
Waste
6.9E+02
2.7E-04
2.1E+02
8.2E-05
6.6E-02
l.OE-08
1.7E+04
6.7E-03
3.3E-03
5.2E-10
5.1E-03
7.9E-10
7.7E-07
1.2E-13
-
Oil ft Gas
Scale/Sludge
3.0E+03
1.2E-03
9.0E+02
3.6E-04
3.6E-03
5.6E-10
-
1.8E+00
2.9E-07
2.8E*00
4.4E-07
3.2E-0?
4.9E-14
-
Geothermal
Waste
3.0E+02
1.2E-04
9.3E+01
3.6E-05
2.1E-03
3.2E-10
1.4E-01
2.1E-08
2.1E-01
3.3E-08
2.6E-07
3.8E-14
-
a The annual whole body effective dose equivalent (mrem/yr).
b The 50-year committed dose equivalent (rarern) from one year of intake.
c The 60-year committed dose equivalent (mrem) from one year of uptake.
d The 70-year lifetime risk of a fatal cancer from one year of exposure.
-------
Table D.S-4. Population doses and health effect* from storage or disposal of diffuse NORM.
Exposure Scenario
Exposure to Resuspended
Parliculates
Dose (person-mrem)*
Health Effects6
River Water
Contaminated by
Groundwater
Dose (person-mrem)*
Health Effects*
River Water
Contaminated by Surface
Runoff
Dose (person-mrem)"
Health Effects'1
Foodstuffs from Fertilized
Soil
Dose (pcrson-mrem)8
Health Effects'"
Uranium
Overburden
2.4E+02
3.7E-05
l.OE+01
1.6E-06
1.1E+05
1.7E-02
--
Phosphate
Waste
2.7E+02
4.4E-06
2.9E+03
4.6E-04
2.3E+05
3.6E-02
-
Phosphate
Fertlliier
4.8E-01
7.6E-08
9.0E-04
1.4E-10
6.3E+00
9.8E-07
2.7E+00
4.2E-07
Coal
Ash
5.0E+01
7.9E-06
3.7E+03
6.8E-04
6.4E+04
8.3E-03
-
Water
Treatment
Sludge -
Fertilizer
4.1E+00
7.3E-07
1.7E-01
2.6E-08
l.OE+03
1.6E-04
3.2E+02
6.0E-05
Water
Treatment
Sludge -
Landfill
3.2E-01
5.5E-08
7.1E-03
1.1E-09
6.1E+01
7.9E-06
-
Mineral
Processing
Waste
1.7E+02
2.7E-05
6.9E-01
9.1E-08
1.7E+04
2.6E-03
-
OUAGas
Scale/Sludge
6.6E+00
9.8E-07
2.7E+02
4.2E-06
3.6E+04
5.6E-03
-
Geothermal
Waste
6.7E+00
1.2E-06
1.7E+01
2.7E-06
4.9E+04
7.6E-03
-
a The 50-year committed dose equivalent to the exposed population from one year of intake (uptake). The nu mber of persons in the exposed population is given in Table D.2-3.
b The number of excess fatal cancers expected in the exposed population as a result of one year of exposure. The number of persons in the exposed population is given in Table
D.2-3.
-------
NORM sector to 6.3 person-mrem for the phosphate fertilizer NORM sector. The
corresponding cumulative health effects to the exposed populations range from 1.7E-02 for
uranium overburden to 9.8E-07 for phosphate fertilizer.
3«4 BENCHMARKING THE DOSE METHODOLOGY
CPG doses from two exposure scenarios were also calculated with the
PRESTO-CPG-PC code (EPA89b) as a benchmark for the dose equations used in the present
analysis. PRESTO-CPG-PC was used instead of PATHRAE because it represents a more
independent check on the calculated doses. The two exposure scenarios calculated with
PRESTO are well water ingestion and dust inhalation of radionudides from disposed oil and
gas production scales and sludges. Insofar as possible, PRESTO used the input parameters
given in section D.2.3. The resulting doses are given by scenario and nuclide in Table D.3-5.
The major differences in the well water ingestion results are due to differences in leach rates.
The major differences in the dust inhalation results are due to vastly different resuspension
rates. If the PRESTO resuspension rates are increased to equal those from the simple
formalism, the inhalation doses are also different by a factor of about three.
3.5 SUMMARY AND CONCLUSIONS
Estimated dominant risks to workers at NORM storage and disposal sites are
summarized in Table D.3-6. For disposal pile workers, the dominant exposure pathway is
direct gamma exposure. 70-year lifetime risks from one year of exposure range from 2.5E-04
for the oil and gas scale/sludge NORM sector to 2.4E-09 for workers on fields repeatedly
fertilized with phosphate fertilizer. Health risks to office workers exposed to indoor radon
inhalation are significantly higher than health risks to disposal pile workers. For indoor
radon inhalation, 70-year lifetime risks from one year of exposure range from 9.3E-02 for the
geothermal waste sector to 1.2E-04 for landfill disposal of water treatment sludge.
D-3-7
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Table D.3-5. Benchmark of methodology for oil and gas scale/sludge.
Simple
Methodology PRESTO
Dose Dose Simple
Nuclide (mr*»m/v"r)
Well Water Ingestion
Po-210 4.7E-01 7.8E-01 0.60
Pb-210 1.4 4.7 0.30
Dust Inhalation
Po-210 2.2E-04 1.1E-06 200
Pb-210 3.3E-04 5.9E-07 559
Ra-226 2.0E-04 2.2E-06 91
Th-228 2.8E-03 2.0E-05 140
D-3-8
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Table D.3-6. Summary of dominant risks to workers from one year
of exposure.
Disposal Pile Worker
Office Worker
Waste Sector
Uranium Overburden
Phosphate Waste
Phosphate Fertilizer
Coal Ash
Water Treatment
Health
Effects8
2.5E-05
3.8E-05
2.4E-09
6.3E-06
8.8E-07
Dominant
Pathway
Direct Gamma
Direct Gamma
Direct Gamma
Direct Gamma
Direct Gamma
Health
Effects8
1.8E-02
1.2E-02
~
1.4E-04
..
Dominant
Pathway
Radon Inhalation
Radon Inhalation
Radon Inhalation
Sludge - Fertilizer
Water Treatment
Sludge landfill
Mineral Processing
Waste
Oil & Gas Scale/Sludge
Geothermal Waste
3.1E-07 Direct Gamma 1.2E-04 Radon Inhalation
5.9E-05 Direct Gamma 2.7E-02 Radon Inhalation
2.5E-04 Direct Gamma 2.1E-02 Radon Inhalation
2.6E-05 Direct Gamma 9.3E-02 Radon Inhalation
a The 70-year lifetime risk of a fatal cancer from one year of exposure.
D-3-9
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Estimated dominant risks to members of the CPG are summarized in Table D.3-7.
The table shows maximum health risks from exposure pathways exclusive of radon inhalation
and health risks from radon inhalation pathways. For exposure pathways exclusive of radon
inhalation the dominant CPG health risks are from direct gamma exposure, either to a
person assumed to live onsite at an abandoned disposal site or from exposure to NORM in
building materials. 70-year lifetime risks from one year of exposure range from 6.7E-03 for
the mineral processing waste NORM sector to 1.1E-08 for a field repeatedly fertilized with
phosphate fertilizer. For radon inhalation, the dominant CPG health risks are estimated to
result from indoor exposure to radon by a person living onsite at an abandoned site. 70-year
lifetime risks from one year of exposure to indoor radon are estimated to be one or two orders
of magnitude higher than risks from direct gamma exposure, ranging from 3.1E-01 for the
geothermal waste sector to 3.0E-06 for a field repeatedly fertilized with phosphate fertilizer.
Estimated population health effects (e.g., cumulative health effects to persons living
offsite) are shown in Table D.3-8 for the reference site and in Table D.3-9 for the total U.S.
population impacted by each NORM sector. The largest number of cumulative health effects
is associated with the coal ash NORM sector, in part because of the large number of sites
required to deplete the total 20-year inventory. Two of the NORM sectors have total
population health effects equal to or greater than unity. The sectors with the lowest total
population health effects are water treatment sludge, oil and gas scale/sludge, and
geothermal waste, each having 0.1 health effects or less from one year of exposure.
The risk assessment results suggest that a relatively moderate number of health
effects could result from the improper use or disposal of diffuse NORM wastes. The risk
assessment results indicate that less than 20 lifetime health effects could occur to the total
population from one year of exposure to diffuse NORM. The dominant NORM sectors from
a population health risk standpoint are coal ash and mineral processing wastes.
These results are based only on the total NORM waste volume generated over the next
20 years. It is anticipated that should the total inventory of NORM wastes accumulated to
date be used instead, the total number of health effects would certainly increase significantly.
However, this assumption would most likely be unrealistic because the accumulated waste
inventory is not in a readily accessible and useable form, as postulated in this report, and
D-3-10
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Table D.3-7. Summary of dominant risks _to the critical population
group from one year of exposure.
Exposure Pathways
Except Radon Inhalation
Radon Inhalation
Waste Sector
Uranium
Overburden
Phosphate Waste
Health
Effects8
1.1E-04
4.4E-03
Dominant
Pathway
Onsite - Direct
Gamma
NORM in
Building
Materials
Health
Effects8
6.0E-02
3.9E-02
Dominant
Pathway
Onsite
Indoor Exposure
Onsite - Indoor
Exposure
Phosphate 1.1E-08
Fertilizer
Coal Ash 7.3E-04
Water Treatment 4.0E-06
Sludge - Fertilizer
Water Treatment 1.4E-06
Sludge T .and fill
Mineral Processing 6.7E-03
Waste
Oil & Gas 1.2E-03
Scale/Sludge
Geothermal Waste 1.2E-04
Onsite Direct
Gamma
NORM in
Building
Materials
Onsite - Direct
Gamma
Onsite Direct
Gamma
NORM in
Building
Materials
Onsite Direct
Gamma
Onsite Direct
Gamma
3.0E-06 Onsite - Indoor
Exposure
4.5E-04 Onsite - Indoor
Exposure
l.OE-03
3.8E-04
8.9E-02
Onsite - Indoor
Exposure
Onsite Indoor
Exposure
Onsite - Indoor
Exposure
7.0E-02 Onsite - Indoor
Exposure
3.1E-01 Onsite - Indoor
Exposure
a The 70-year lifetime risk of a fatal cancer from one year of exposure.
D-3-11
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Table D.3-8. Summary of cumulative health effects per reference
site from one year of exposure.
Waste Sector
Health Effects*
Uranium Overburden
Phosphate Waste
Phosphate Fertilizer
Coal Ash
Water Treatment Sludge -
Fertiliser
Water Treatment Sludge -
Landfill
Mineral Processing Waste
Oil & Gas Scale/Sludge
Geothermal Waste
1.7E-02
3.5E-02
9.8E-07
8.9E-03
1.6E-04
7.9E-06
2.6E-03
5.6E-03
7.6E-03
Dominant Pathway
River Water Contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
River Water contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
River Water Contaminated
by Surface Runoff
a Number of excess fatal cancers (70-year lifetime risk) expected in the exposed population
as a result of one year of exposure. The number of persons in the exposed population per
reference site is given in Table D.2-3.
D-3-12
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Table D.3-9. Summary of cumulative health effects in the United
States from one year of exposure.
Waste Sector
Number of Sites for
20-Year Inventory
Fertilizer
Water Treatment Sludge -
Mineral Processing Waste
Oil & Gas Scale/Sludge
Geothermal Waste
2.3E+02
6.7E+02
l.OE+01
2.0E+00
Health Effects8
Uranium Overburden
Phosphate Waste
Phosphate Fertilizer
Coal Ash
Water Treatment Sludge -
1.4E+01
1.5E+01
9.4E+05
1.3E+03
4.4E+02
2.4E-01
5.2E-01
9.2E-01
1.2E+01
7.0E-02
1.8E-03
1.7E+00
5.6E-02
1.5E-02
a The number of excess fatal cancers (70-year lifetime risk) expected in the total U.S.
population as a result of one year of exposure.
D-3-13
-------
currently there is no outlet which would allow that much NORM waste to be recycled.
Given the uncertainties associated with waste volumes, radionuclide concentrations,
and exposure pathway models and parameters, it is estimated that the results of this risk
assessment analysis are within a factor of 3 of results obtained when using more
sophisticated computer codes. In general, it is suspected that the variability of the results
is asymmetric, in the sense that the degree of conservatism is more pronounced on the lower
range of the input parameters and assumptions »-h«*« on the higher end. Accordingly,
depending upon a specific input parameter or assumption, the results may reveal a still
greater degree of variability. Finally, it should be noted that changing a parameter does not
always yield results that are directly proportional since competing factors may nullify an
increase in a specific parameter.
These NORM waste risk assessments are based on relatively simple models that
incorporate a number of assumptions, some better defined than others. Thus the results
incorporate some uncertainty. The results imply, however, that the number of potential
health effects associated with some NORM sectors may be significant enough to warrant
more detailed modeling of NORM waste storage and disposal practices in order to further
refine the risk assessment analysis.
D-3-14
-------
CHAPTER D
TOES
EPA87a U.S. Environmental Protection Agency, "PATHRAE-EPA: A Performance
Assessment Code for the Land Disposal of Radioactive Wastes, Documentation
and Users Manual," Office of Radiation Programs, EPA 520/1-87-028,
December 1987.
EPASTb U.S. Environmental Protection Agency, "PRESTO-EPA-POP: A Low-Level
Radioactive Waste Environmental Transport and Risk Assessment Code,
Volume I, Methodology Manual," Office of Radiation Programs, EPA
520/1-85-001, draa, November 1987.
EPA88a U.S. Environmental Protection Agency, "Low-Level and NARM Radioactive
Wastes, Draft Environmental Impact Statement for Proposed Rules, Volume
1, Background Information Document," EPA 520/1-87-012-1, June 1988.
EPA88b U.S. Environmental Protection Agency, "Limiting Values of Radionuclide
Intake and Air Concentration and Dose Conversion Factors for Inhalation,
Submersion, and Ingestion," EPA-520/1-88-020, September 1988.
EPA89a U.S. Environmental Protection Agency, "Risk Assessment Methodology,
Environmental Impact Statement for NESHAPS Radionuclides, Volume 1,
Background Information Document," EPA 520/1-89-005, September 1989.
EPA89b U.S. Environmental Protection Agency, "A PC Version of the
PRESTO-EPA-CPG Operation System," EPA 520/1-89-017, April 1989.
NRC87 U.S. Nuclear Regulatory Commission, "Methods for Estimating Radioactive and
Toxic Airborne Source Terms for Uranium Milling Operations," Regulatory
Guide 3.59, March 1987.
ROG85 Rogers, V.C. et al., "The PATHRAE-T Performance Assessment Code for
Analyzing Risks From Radioactive Wastes," Rogers and Associates Engineering
Corp. report to U.S. Department of Energy, RAE-8339/12-2, December 1985.
D-R-1
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E. CONCLUSIONS AND RECOMMENDATIONS
E.1 CONCLUSIONS
The Environmental Protection Agency (EPA), in September 1989, developed a
preliminary risk assessment characterizing generation and disposal practices of wastes which
contain diffuse levels of naturally-occurring radioactive materials (NORM). Such wastes are
typically generated in large volumes of potentially recyclable materials which contain Ra-226
at elevated concentrations. The preliminary risk assessment report was prepared as an initial
step in the development of acceptable standards governing the disposal and re-use of NORM
waste and material. These bulk wastes and materials are of such large volume and relatively
low radionuclide concentrations that it was deemed inappropriate to include them within the
scope of other proposed rulemaking activities. The preliminary report indicated that there
exists a need to further review the data, assumptions, and models used in that report,
provide additional information on categories of diffuse NORM wastes which were not
explicitly addressed, and perform a more detailed risk assessment. This report, prepared in
response to these recommendations, presents the results of further characterization efforts
and a revised risk assessment analysis.
All soils and rocks are known to contain some amounts of naturally-occurring
radioactive material (NORM). The major radionuclides are uranium and thorium, and their
respective decay products. One of the decay products is radium (Ra-226) and its daughters
products, which are the principal radionuclides of concern in characterizing the redistribution
of radioactivity in the environment. Radium is normally present in soil in trace
concentrations of about one picocurie per gram (pCi/g).
Certain processes, however, tend to reconcentrate or enrich the radioactivity to much
higher levels in the resulting waste or by-product materials. The concentration of radium in
wastes «»n vary considerably and primarily depends upon the initial levels and processes
reconcentrating the radium. Such processes include mining and beneficiation, mineral
processing, coal combustion, the treatment of drinking water, among others. Some of the
NORM wastes or materials are being generated in large quantities and typically disposed or
E-l-1
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stored at the point of generation. At times, however, NORM material and waste are used in
various applications which may result in unnecessary radiation exposures, potential adverse
health effects, or environmental contamination.
NORM waste generation and disposal practices were, characterized for eight NORM
sectors. The largest inventories of NORM wastes are associated with mineral processing,
phosphate rock production, uranium mining, and coal combustion from utility and industrial
boilers. Each of these processes generate large volumes of waste with annual production rates
of several million metric tons. Over the next 20 years, these NORM sectors will generate
significant waste inventories ranging from about 1 to 20 billion metric tons. Smaller
quantities of waste are generated by the petroleum industry (oil and gas pipe scale) and by
drinking water treatment facilities. It is anticipated that water treatment facilities and the
petroleum industry will generate 6 and 13 million metric tons of waste over the next 20
years, respectively. Phosphate fertilizers, while not a waste, are included in this analysis
because of their elevated radium concentrations. It is estimated that about 100 million metric
tons of fertilizers will be applied in agricultural fields over the next 20 years.
It should be noted that these estimates incorporate a large degree of uncertainty since
the characterization of these NORM sectors is based on limited information and data (see the
next section for further details on this aspect). It was also concluded that for some NORM
sectors, waste generation and disposal practices were partially represented or that the
available information was deemed to be inadequate or incomplete. Accordingly, there is a
need to better characterize the radiological and physical properties of these wastes, evaluate
NORM waste disposal and application practices, and refine waste generation rate estimates.
The risk assessment analyses addresses several exposure pathways to the public and
to workers for each of the eight NORM sectors. Such pathways include direct radiation
exposures while standing on NORM waste or material, standing at a hypothetical facility
fence post, and due to the incorporation of waste in building materials. Inhalation exposures
are due to resuspended airborne particulates and radon emissions from waste piles. Indoor
radon in structures is also considered for homes erected over waste and incorporating NORM
in building materials.
E-l-2
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For internal exposure, this assessment considers the drinking of ground and surface
water, consumption of vegetables and fruits, and the ingestion of animal products (meat and
milk). The risk assessment assumes that the water and foodstuff contain residual levels
radioactivity. In water, it is assumed that waste leachates have contaminated ground and
surface water sources. All water needs are assumed to be supplied from a well or surface
stream, including domestic and agricultural uses. Vegetables and fruits are assumed to be
grown in soils containing NORM waste and livestocks are assumed to be grazing in
contaminated pastures.
The results reveal that for the Critical Population Group (CPG), six NORM sectors
dominate with annual non-radon risks ranging from 1.1 x 10"* to 6.7 x 10"3. These sectors,
in a decreasing order of risks, are mineral processing waste, phosphate waste, oil and gas
scale, coal ash, geothermal waste, and uranium overburden. The remaining sectors are
characterized by annual risks which are less than 6.0 x 10"6. The dominant exposure
pathways associated with these risks include direct radiation from the use of NORM wastes
in building materials, and while standing on NORM wastes, or at the fence post. In terms
of indoor radon exposures, all NORM sectors except phosphate fertilizer dominate with
annual risks ranging from 0.31 to 3.8 x 10"*. The phosphate fertilizer NORM sector has a
resulting annual CPG risk of 3.0 x 10"6. In the aggregate, the CPG risks associated with all
ingestion exposure pathways are typically 10"6 or less. The annual risks due to downwind
radon exposures are less than 10"7 across all NORM sectors.
The risks to disposal pile workers range from 2.5 x 10"4 for the oil and gas scale sector
to 2.4 x 10"9 for the phosphate fertilizer sector. For office workers, the risks are mainly from
radon daughter inhalation and range from 9.3 x 10"2 for geothermal waste to 1.2 x 10"4 for
water treatment sludge.
The number of population health effects at each generic site, ranges from 3.5 x 10"2
to 7.9 x 10"6. In decreasing order of potential number of health effects, the NORM sectors are
phosphate waste, uranium overburden, coal ash, geothermal waste, oil and gas scale, mineral
processing, water treatment, and phosphate fertilizers. The dominant exposure pathway is
radon for four of the seven NORM sectors. Ingestion of well water (for both, oil and gas scale,
and coal ash) and foodstuff (for phosphate fertilizers) are the controlling pathways for the
remaining three NORM sectors. The potential number of health effects due to downwind
E-l-3
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radon exposure ranges from 3.5 x 10'2 to 5.5 x 10"*. In decreasing order of potential number
of health effects, these NORM sectors are phosphate waste, uranium overburden, mineral
processing waste, oil and gas scale, coal ash, water treatment sludge, and phosphate
fertilizers.
The risk assessment results suggest that a relatively moderate number of health
effects could result from the improper use or disposal of diffuse NORM wastes. The risk
assessment results indicate that about 30 population health effects could occur from
exposures received over the next 20 years, with some individual risks as high as 3 in a 1000.
The dominant NORM sectors and their respective health effects are phosphate fertilizers with
17, mineral processing with 2, coal ash with 12, and water treatment sludge with 1. These
results are based only on the total NORM waste volume generated over the next 20 years.
It is anticipated that should the total inventory of NORM wastes accumulated to date be used
instead, the total number of health effects would certainly increase significantly. However,
this assumption would most likely be unrealistic because the accumulated waste inventory
is not in a readily accessible and useable form, as postulated in this report, and currently
there is no outlet which would allow that much NORM waste to be recycled.
Given the uncertainties associated with waste volumes, radionuclide concentrations,
and exposure pathway model and parameters, it is estimated that the results of this risk
assessment analysis are within a factor of 3 of results obtained when using more
sophisticated computer codes. In general, it is suspected that the variability of the results is
asymmetric, in the sense that the degree of conservatism is more pronounced on the lower
range of the input parameters and assumptions than on the higher end. Accordingly,
depending upon a specific input parameter or assumption, the results may reveal a still
greater degree of variability. Finally, it should be noted that changing a parameter does not
always yield results that are directly proportional since competing factors may nullify an
increase in a specific parameter.
Given that these results are based on a number of assumptions, some better defined
than others, these estimates are still uncertain. The results imply, however, that the number
of potential health effects may be significant enough to warrant additional characterization
of NORM waste generation and disposal practices in order to further refine risk assessment
analysis.
E-l-4
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Even with these uncertainties, however, it is clear that a significant number of health
effects and high risks could occur for a limited number of individuals in exposed populations.
Therefore, it is worth evaluating the regulatory options that exist to control NORM wastes.
One option for regulating the disposal of NORM wastes would be the use of RCRA, to require
disposal in RCRA hazardous waste disposal facilities. This may not be a particularly feasible
option as RCRA does not now include radioactivity as a characteristic used to define
hazardous wastes.
Another option with RCRA would be the use of Subtitle D requirements for regulated
disposal. This option is being studied by EPA for certain mineral processing wastes, but the
use of Subtitle D is less desirable, since Subtitle D lacks Federal enforcement capabilities.
Another major constraint with the use of RCRA, however, in that RCRA only has authority
over waste disposal. Since much of the health impact from NORM waste comes about from
reuse that is not appropriate, RCRA could not be used to control that aspect since it would
be considered recycling and not waste disposal.
There are currently regulations being considered which apply to the disposal of higher
concentrations of NORM wastes (greater that 2,000 pCi/g). These regulations are being
prepared under the authority of Section 6 of TSCA, which could also be used to regulate the
diffuse NORM wastes. Under Section 6, materials found to present unreasonable risk to the
public can be controlled in a variety of manners, including requirements on disposal,
manufacture, distribution in commerce, and use of warning labels and record keeping.
Finally, the EPA, under the Toxic Substance and Control Act (TSCA), could assume
the authority to regulate the manufacture and disposal or commercial distribution of items,
materials, and waste containing NORM found to present an unreasonable public health risk.
Additional requirements could involve the placement of warning labels on some items or
signs in some areas and necessitate a record keeping and inventory system for specific
categories of NORM material. Currently, there is an impetus to consider using TSCA to
regulate higher activity NORM wastes and it may be appropriate to extend TSCA to also
regulate diffuse NORM wastes as well. With TSCA, the EPA could prohibit certain use and
application of NORM wastes which present unreasonable public health risks or could result
in environmental contamination.
E-l-5
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F.2 RECOMMENDATIO> 3
The following summar zes a number of specific Recommendations based on the
information and data presente in Chapter B. It is recommended that in subsequent efforts
these aspects be considered in refining and updating the existing characterization of each
NORM sector and risk assessm :nt analyses. It should be noted that these recommendations,
as discussed below, are not all < imprehensive, but are included here for illustrative purposes
and to give a sense of perspect /e on the type and scope of the uncertainties associated with
the results of this analysis. Th . reader is referred to Chapter B for more details regarding
each NORM sector.
FJ2.1 Waste Vol«m«»« and C laracteristics
For some of the eight I ORM sectors, there is a need to further characterize waste
volumes and generation rates, a some cases, the assumed amount of wastes contained in the
pile or held in inventory ma} in fact represent varying fractions or multiples of yearly
generation rates. There may . Iso be some inconsistencies between the volume of NORM
waste assumed to be stored r - a site and the yearly average quantity based on current
practices and projections. The unounts and total waste inventory stored at any one site is
known to vary since some wa tes are always added and subjected to waste management
procedures. Because of this dyr imic process, it may be in fact difficult to define a generic site
which is representative of a s lecific NORM sector. It should also be noted that in some
instances, because of a declinir i industry or business, the projected 20-year waste inventory
is dwarfed by the total amount , of waste already stockpiled from past activities. It may just
be that any additional waste v hich will be generated over the next 20 years, in itself, does
not present a significantly grez er degree of risk when compared to the risks associated with
existing inventories. According y, there is a need to determine if a specific NORM sector or
site should be considered unc jr the umbrella of reclamation program, or fall under the
jurisdiction of future NORM re ulations. A threshold, based on yearly waste generation rates
and existing waste inventorie , could perhaps define the category (either reclamation or
subject to proposed NORM reg ilations) in which a NORM sector or site belongs.
E-l-6
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It was noted that NORM wastes may be used in several types of applications, from
building and construction materials to consumer products. Because of the bulk quantities,
there is a need evaluate, based on a survey, the mobility of this material from the point of
generation to the point of processing, use, or manufacturing, including amounts of wastes
used or incorporated in building materials at the local and regional or national level. For
example, what are the technical and economic factors which may lead a specific user to select
one NORM waste generator among others? Are there threshold quantities below which the
transportation costs outweigh the cost of the material itself? Such considerations may reveal
that perhaps the bulk the waste is simply not used or, if so, only in limited quantities and
within the locality in which they are produced. Consequently, there may be a limit inthe rate
of utilization of NORM wastes. Should this be the case, the profile of the population risks and
health effects may shift from what may have been perceived as exposures to distant
end-users to only a very few nearby site residents. The potential health risks may then be
confined to short distances around each waste generator. Some sources of information and
data which may help answering these questions, as well as others, include the upcoming
results of the American Water Works Association 1989 survey of water utilities, the federal
reporting data system of water utilities, and the American Petroleum Institute NORM data
bank.
Another point which needs to be examined in greater depth, given the physical
characteristics of such wastes, is the potential re-use limited to only a few application? If so,
there is a need to reevaluate the risk assessment models to ensure that the exposure
pathways being considered are indeed realistic with current or anticipated applications. For
example, in considering uranium overburden, would such material be used as backfill or for
land reclamation on large scale given that mining sites are typically located in arid and
remote regions of the U.S.? Similarly, are certain NORM wastes suitable for incorporation
in construction materials? For example, wastes which have been subjected to chemical
extraction or processing may have physical properties which make them less desirable than
other competing materials. Conceivably, such wastes will have a narrower range of
applications and, hence, a limited number of potential exposure pathways.
E-l-7
-------
This report has identified that, for any given NORM sector, it is not uncommon for
radionuclide concentrations to vary by several orders of magnitude. This variation is
primarily due to two factors: 1) the natural variability of radionuclide concentrations in any
materials, and 2) processes or practices which are specific to a NORM sector. The wastes
generated by some of the sectors is poorly understood because of the paucity of the data. The
literature contains only a few studies and in most cases, a few specific sites were evaluated
for each waste form. In addition, the characterization of some of the industries was based on
very limited field sampling and analysis programs, with a limited number of samples taken
at each site and in some instances none at all It is generally believed by geologists that the
presence of naturally-occurring radioactivity is more dependent upon the geological formation
or region than a particular type of mineral ore. It will also be apparent that ores often
contain many different minerals. Accordingly, it cannot be assumed that the radionuclide
content of one type of ore and its associated wastes will be representative of a NORM sector
or industry.
The quantity of waste materials and their physical and radiological characteristics
differ widely among the various NORM sectors. In addition, depending on the processing or
treatment methods employed, some of the resulting wastes can contain elevated
concentrations of naturally-occurring radionuclides. Furthermore, materials stockpiled at any
one site are not always necessarily waste. Some of the wastes are in fact additional resources
which may be subjected to further processing to extract additional minerals.
There have been reports that some of the more uncommon metals have highly
radioactive waste products. Also, some of the processes associated with metal extraction
appear to highly concentrate the radionuclides and enhance their environmental mobility.
Some published information and data to support these arguments have been presented, but
in most cases it is suggested that further studies be conducted prior to reaching any
conclusions.
In considering the presence of radioactivity, there is a need to refine the relationship
between waste volumes and radionuclide concentrations. The existing assessment relies on
average concentrations. It is, however, suspected that concentrations are log-normally
E-l-8
-------
distributed and that the bulk volume is primarily characterized by very low concentrations.
Furthermore, t-hi« assessment noted that for some mineral processing wastes, some ores (e.g.,
copper) may contain uranium in elevated concentrations (at milling grade) which are
equivalent to those found in uranium mines. Such findings, if confirmed, may have a
significant impact on the results and conclusions in the next risk assessment. With respect
to waste forms there is also a need to reevaluate the physical characteristics of the waste
since t*"3 information is used to model the radiological source terms and environmental
transport and mobility. For example, the following items, among others, need to be
re-examined: waste permeability, particle size vs. specific activity, porosity, hydraulic
conductivity, leach rate or coefficient of distribution (Kd).
F.2.3 EnvlropTn«»ntnl Transport Mechanisms
The current analyses consider several transport mechanisms by which NORM
materials or wastes could become a potential source of exposures. These transport
mechanisms include the re-use of NORM wastes into building materials, introduction of
NORM materials in construction activities, application of such wastes as soil conditioners,
atmospheric dispersion, and the infiltration of waste leachates in ground water aquifers and
surface streams. A last category, although not truly an environmental transport mechanism,
addresses direct radiation exposures, to the nearby resident, due to the presence of the
wastes either stored in piles or spread in soils and agricultural fields.
This risk assessment assumes that the bulk of the material is used in its basic form,
for example, unprocessed and as an additive or as clean fill. It should be noted that some
industrial sectors are processing such wastes for mineral resources recovery or as feedstock
for other types of products. It is suspected that additional processing may create a substream
of industrial wastes whose radiological properties are unknown. The commercial end product
may also have radiological properties which may or may not pose a public health risk. This
type of intermediate application or processing across several industrial sectors may result in
the generation of new waste streams and other forms of waste disposal practices.
E-l-9
-------
F.2.4 Exposure Pathways
The risk assessment analyses addressed several exposure pathways for ea h of the
eight NORM sectors. Such pathways include direct radiation exposures while sta iding on
NORM waste or material, standing at a hypothetical facility fence post, and di 3 to the
incorporation of waste in building materials. Inhalation exposures are due to resi spended
airborne particulates and radon emissions from waste piles. Indoor radon in structui ;s is also
considered for homes erected over waste and incorporating NORM in building ma 'rials.
For internal exposure, this assessment considers the drinking of ground an surface
water, consumption of vegetables and fruits, and the ingestion of animal products (: leat and
milk). The risk assessment assumes that the water and foodstuff contain residv il levels
radioactivity. In water, it is assumed that NORM waste leachates have contaminate I ground
and surface waters. All water needs are assumed to be supplied from a ground wat< r well or
surface stream, including domestic and agricultural uses. Vegetables and fruits are issumed
to be grown in soils containing NORM waste and livestocks are assumed to be g azing in
contaminated pastures.
The exposure pathways selected for this assessment are comprehensive a: d are in
agreement with similar studies performed by the EPA and others. It is currently ei /isioned
that no new pathways need to be considered unless currently unforeseen mode of e :posures
are identified as a results of additional investigation. Consequently, should any a lew risk
assessment analyses be required, existing model parameters should be refined to more
accurately represent each exposure pathway.
F.2.5 Exposed Populations
Exposed populations include workers, the critical population group (CPG) and the
general population in the vicinity of the disposal sites. The analyses consider the states in
which a NORM site might be located, where the waste material might be used 01 applied,
population densities near each site, location of the nearby resident, and an averaj ! type of
residence.
E-l-10
-------
As was noted earlier, the size of the exposed population may be dependent upon the
utilization rate of any specific NORM waste. Should this be the case, the profile of the
exposed population may then shift to nearby residents rather than distant end-users. The
potential health risks may then be confined to short distances around each waste generator.
In assessing the potential number of health effects, there may also be a need to consider
expressing these results as waste volume weighted averages, which would take into account
waste generation rates or existing inventories and the size of the exposed population.
There is also a need to refine the connection between exposure pathways and the size
of the exposed population. For example, when considering the ingestion of contaminated
vegetables and animal food by-products, it may be unrealistic to assume that a NORM site
could impact a food supply which cannot be produced in the immediate surroundings or fulfil
the needs of large population centers. For example, in considering sites located in arid and
remote regions of the southwest, it is highly improbable that a large population segment
would be impacted by a metal mining and processing facility.
F.2.6 Evaluation of Overall TTncertainties
The assumptions and information used in this risk assessment analysis were reviewed
and, for each NORM sector, the parameters and assumptions were examined, and ranked as
to their level of uncertainty. For each exposure pathway, this review considered each NORM
sector and waste, radiological source terms, environmental transport mechanisms, types of
exposure pathways, and exposed populations.
A simple ran long system is used to attach a level of priority to the identified
parameters. The ranking process reflects information gathered to date, literature review, and
technical judgement. For this exercise, a simple numerical ranking scheme is used, for
example, a value of 1 to characterize a parameter with the least uncertainty and 5 for one
with the most. Table F.2-1 presents the results of this ranking process. From this tabulation,
the following conclusions are reached:
The ranking each NORM sector, in a decreasing order of uncertainty, is as
follows: 1) mineral processing, 2) petroleum pipe scale, 3) water treatment,
E-l-11
-------
Table E.2-1. Sources and pathways uncertainties ranking/**
Item
Wastes:
Sites
Volumes
Forms
Pro pert.
Config.
Disposal
Uses
Radiological:
Nudides
Concent.
Propert.
Environmental Transp.
Disposal
Applctn.
Atmosph.
Surf. ttjO
Grnd. H2O
Exp. Pathways:
Inhalatn.
Ext. Rad.
Ingestion
Population:
Sites
Pop. Dens.
CPG
MGP
SUM;
Uranium
Ovrbrdn
1
2
2
2
3
2
3
2
2
2
2
3
3
3
4
1
1
1
2
2
2
2
46
Phosph. Pert.
1
1
1
1
1
1
2
2
2
2
2
3
2
2
2
1
1
1
1
1
2
2
34
NA
2
2
3
NA
NA
1
2
2
2
NA
1
2
2
2
1
2
1
1
1
2
2
31
Coal
Ash
2
2
1
2
2
1
2
r
1
2
2
3
2
2
2
1
3
1
3
3
2
2
PetroL
Scales
3
3
3
2
4
3
3
1
2
3
3
3
3
3
3
2
3
2
3
3
4
4
Water
Treat.
3
3
3
3
3
2
2
3
3
3
2
2
2
2
2
1
4
1
2
2
2
2
42
63
52
3
4
4
4
3
4
4
3
3
4
3
4
2
2
2
2
4
2
3
3
4
4
71
(a) Ranking system reflects information gathered to date, literature survey, and technical judgeir nt. For
example, a value of 1 characterizes a parameter with the least uncertainty and a value of 5 for ne with
the most.
E-l-12
-------
4) uranium overburden, 5) coal ash, 6) phosphate waste, and 7) phosphate
fertilizers.
Three NORM sectors stand-out as requiring further evaluation, these are
mineral processing, water treatment, and petroleum oil/gas scale.
For two NORM sectors, the ranking scheme indicates that the information
gathered to date is sufficiently detailed for the purpose of this risk
assessment. These 2 NORM sectors include, uranium overburden and coal
ash. It may still be necessary to revisit these two NORM sectors for the
purpose of updating some of the descriptive sector parameters and revise
the risk assessment analysis.
-The phosphate waste and fertilizer NORM sectors are deemed to be
adequately characterized, but may nevertheless require some further
analysis simply for the purpose of refining the risk assessment analysis.
E-l-13
-------
APPENDIX A
TABULATIONS OF DOSE AND
RISK CALCULATIONS TO CHAPTER D
-------
WORKER - DIRECT OAIOIA EXPOSURE
ten Unnlum Overburden
& 1.10E-01
S- 1.33E+05
D(mrem) - G S C * DFQ
R(fatal cancan) . G S * C * RFC
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1.66E+01
1.66E+01
2.37E+01
1.00E+00
1.00E+00
2.37E+01
1.00E+00
2.37E+01
2.37E+01
1.20E+00
DPQ
8.SSE-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
RPQ
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.SOE-14
6.50E-12
D
2.08E-04
7.07E-02
5.79E+01
4.93E+00
1.32E+00
3.08E-02
9.60 E-04
2.77E-02
2.22E-02
2.93E-01
R
8.01 E-11
2.67E-08
2.25E-05
1.90E-06
5.12E-07
1.21 E-08
3.80E-10
1.07E-08
8.67E-09
1.14E-07
TOTAL 6.46E+01 2.51 E-05
A-2
-------
W1b
WORKER DIRECT GAMMA EXPOSURE
Ian Phoiphmti
G- 1.10E-01
& 1.59E+05
(Xmram) . G * S * C * DFG
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal canec
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
ITS) - G * S
era
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
C * RFC
RFO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
3.95E-04
1.34E-01
9.64E+01
1.59E+00
4.27E-01
2.02E-02
3.10E-04
8.68E-03
6.73E-03
8.76E-02
R
1.52E-10
5.08E-08
3.75E-05
6.14E-07
1.65E-07
7.96E-09
1.23E-10
3.36E-09
2.62E-09
3.41 E-08
TOTAL 9.87E+01 3.84E-05
A-3
-------
W1e
WORKER - DIRECT GAMMA EXPOSURE
Photphato Fertilizer
G. 1.10E-01
S- 9.66E+04
D(mram) - G * S C DFQ
R(fatal cancers) - Q * S '
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1 .80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1 .70E-02
1 .70E-02
8.60E-04
GFQ
8.SSE-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-OS
' C * RFQ
RPQ
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
1 .64E-08
5.57E-06
4.44E-03
1.22E-03
3.27E-04
1.51E-05
2.16E-07
1 .45E-05
1.16E-05
1.53E-04
R
6.31 E-1 5
2.10E-12
1.73E-09
4.70E-10
1.26E-10
5.95E-12
8.56E-14
5.60E-12
4.52E-12
5.94E-11
TOTAL 6.18E-03 2.40E-09
A-4
-------
W1d
tor.ComlAth
G- 1.10E-01
S. 7.98E+04
D(mrem) - G * S * C * DFG
R(fatal cancers) - G S '
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1 .80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E«00
1 .60E-01
OPQ
8.5SE-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-06
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
' C * RFG
HTO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
S.2SE-05
1.74E-02
5.42E+00
9.47E+00
1.43E+00
1.79E-03
1.21E-03
2.32E-03
1.86E-03
2.35E-02
R
2.03E-11
6.57E-09
2.11E-06
3.6SE-06
5.53E-07
7.07E-10
4.79E-10
8.98E-10
7.24E-10
9.13E-09
TOTAL 1.64E+01 6.33E-06
A-5
-------
WORKER - DRECT OAMHA EXPOSURE
ten Wittr Tnmt Sludg* (Firtlllnr)
G- 1.10E-01
S- 1.13E+05
0(mram) = G * S C DFQ
R(fatal cancers) - G * S * C * RFG
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
4.00E-01
4.00E-01
6.40 E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.80E-01
1.60E-01
1.20E-03
OPB
8.SSE-10
2.91 E-07
1 .67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
HPO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
4.25E-06
1 .45E-03
1.33E+00
3.3SE-02
8.99E-01
8.83E-06
6.52E-06
1.59E-04
1.27E-04
2.49E-04
R
1.64E-12
5.47E-10
5.17E-07
1 .29E-08
3.48E-07
3.48E-12
2.59E-12
6.17E-11
4.97E-11
9.70E-11
TOTAL 2.26E+00 8.79E-07
A-6
-------
W1f
WORKER MRECT GAMMA EXPOSURE
tan Wit r Tntl Sludg* (Lmndflll)
' » 1.10E-01
: =. 1.06E+05
D(mram) . G S * C DFQ
R(fatal cai *rs) - Q * S * C * RFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
C
1.50E-0
1 .50E-0
2.40E-0
3.00E-0
3.00E-0
3.00E-0
3.00E-0
6.00E-0
6.00E-0
5.00E-0
DPO
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-OS
8.88E-08
6.56E-08
8.00E-08
6.4 IE-OS
1.67E-05
RFB
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
O
1.50E-06
5.09E-04
4.67E-01
1.18E-02
3.16E-01
3.11 E-06
2.29E-06
5.60E-OS
4.48E-05
9.74E-OS
R
5.77E-13
1.92E-10
1.82E-07
4.55E-09
1 .22E-07
1.22E-12
9.09E-13
2.17E-11
1.75E-11
3.79E-1 1
TOTAL 7.96E-01 3.09E-07
A-7
-------
W1g
tar: MiMraJ Proc*M/n0 WM«*
G- 1.10E-01
S- 1.36E+05
0(mram) - G S C DFG
R(fatal cancan) - G * S '
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E*01
1.00E+01
3.50E+01
3.50E*01
1.80E+00
OPO
8.55E-10
2.91 E-07
1 .67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-OS
' C ' RFG
HFB
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
3.20E-04
1.09E-01
8.74E+01
5.04E+01
1.35E+01
4.65E-02
9.81 E-03
4.19E-02
3.36E-02
4.50E-01
R
1.23E-10
4.11 E-08
3.40E-05
1 .94E-05
5.24E-06
1.83E-08
3.89E-09
1 .62E-08
1.31 E-08
1.75E-07
TOTAL 1.52E+02 5.90E-OS
A-8
-------
Wlh WORKER .DMECrOAiaiA EXPOSURE
ton Oil A On SemU/ Studg»
Q. 1.10E-01
S- 1.20E+05
D(mrani) - G * S C DFG
R(fatal cancan) - Q S * C * RFQ
Nuelldi
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1 .55E+02
1.55E+02
1.55E-f02
5.50E+01
5.50E+01
. .
- -
- -
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
- -
- -
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.SOE-11
- -
- -
- -
1 .75E-03
S.95E-01
3.42E+02
2.45E+02
6.56E+01
- -
6.7SE-10
2.25E-07
1.33E-04
9.44E-05
2.54E-05
- -
- -
TOTAL 6.53E+02 2.53E-04
A-9
-------
W1I WORKER - DIRECT OA1HIA EXPOSURE
ton 6*otfMHMJ Wm»t»
Q. 1.10E-01
S- 1.30E+04
(Xmrem) - G * S C * DFQ
R(fatal cancan) - Q * S * C * RFG
Nuelld* C OFO HFB
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.10E+02
1.10E+02
1.60E+02
3.00E+01
1.10E+02
-
»
. .
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
- -
- -
- -
- -
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
- -
- -
1 .34E-04
4.58E-02
3.82E+01
1.45E*01
1.42E+01
- -
- -
- -
S.19E-1 1
1.73E-08
1 .49E-OS
S.58E-06
5.51 E-06
-
-
TOTAL 6.69E+01 2.60 E-0 5
A-10
-------
W2a
WORKER DUST INHALATION
ton Urmnlum Onrburdan
O.1.68E-03
& 1.00E+00
O(mrem) - 6 S * C * DRnh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal eanet
e
1 .66E+01
1.66E+01
2.37E+01
1.00E+00
1.00E+00
2.37E+01
1 .OOE+00
2.37E+01
2.37E+01
1.20E+00
n) - Q * S
DRnh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C RRnh
RFInh
1 .SOE-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1.90E-08
D
2.62E-04
3.90E-04
3.42E-04
5.71 E-04
8.06E-06
1.31E-02
2.69E-03
5.18E-03
4.78E-03
2.42E-04
R
4.18E-1 1
6.14E-11
5.18E-11
8.90E-11
1.24E-12
2.03E-09
4.20E-10
7.96E-10
7.57E-10
3.83E-11
TOTAL 2.76E-02 4.29E-09
A-11
-------
W2b
WORKER DUST INHALATION
iOf! PhOSphttB MflMtft
G.1.68E-03
S- 1.00E+00
D(mrem) . Q S * C * DFInh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fata) eancc
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
ire) - Q * S
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E^OO
1.30E-01
1.20E-01
1.20E-01
C * RFInh
RFInh
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1 .90E-08
D
4.17E-04
6.21 E-04
4.77E-04
1.54E-04
2.18E-06
7.21 E-03
7.26E-04
1.35E-03
1.21 E-03
6.05E-06
R
6.65E-1 1
9.76E-1 1
7.21 E-11
2.40E-11
3.36E-13
1.11E-09
1.13E-10
2.08E-10
1.92E-10
9.58E-12
TOTAL 1.22E-02 1.90E-09
A-12
-------
W2e
WORK! ?-DUST INHALATION
Plk :phmt» Fertilizer
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
&
&
D(mrem) -
R(fatal cane
c
1 .80E-03
1 .80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1 .70E-02
1 .70E-02
8.60E-04
1.68E-03
1.00E+00
S ' C * DRnh
«) - G * S
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C * Rflnh
RFInh
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
S.10E-08
2.50E-07
2.00E-08
1.90E-08
1.90E-08
D
2.84E-08
4.23E-08
3.61 E-08
1 .94E-07
2.74E-09
8.87E-06
8.33E-07
3.71 E-06
3.43E-06
1.73E-07
R
4.S4E-15
6.6SE-15
5.46E-15
3.03E-14
4.23E-16
1.37E-12
1.30E-13
5.71E-13
5.43E-13
2.75E-14
TOTAL 1.73E-05 2.69E-12
A-13
-------
W2d
WORKER DUST INHALATION
for: Cod
G- 1.68E-03
S-1.00E+00
O(mreni) - G S C DRnh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fataJ canct
c
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
ra) - Q * S
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C * RFlnh
RFInh
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1 .90E-08
D
1.11E-04
1 .60E-04
5.35E-05
1 .83E-03
1 .4SE-05
1 .28E-03
5.64E-03
7.21 E-04
6.6SE-04
3.23E-OS
R
1.76E-1 1
2.51 E-11
8.08E-12
2.85E-10
2.24E-12
1.97E-10
8.82E-10
1.11E-10
1.05E-10
5.11 E-1 2
TOTAL 1.05E-02 1.64E-09
A-14
-------
W2* WORKER DUST INHALATION
ton Wmtw Tnmt Sludgi (Firtlllxir)
G. 1.68E-03
S-1.00E+00
D(mrem) - Q S * C * DFInh
R(tatal cancan) - Q S * C RFinh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1.20E-03
DFlnh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
RFInh
1 .SOE-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1.90E-08
D
6.32E-06
9.41 E-06
9.2SE-06
4.57E-06
6.45E-06
4.44E-06
2.15E-05
3.49E-OS
3.23E-05
2.42E-07
R
1.01E-12
1.48E-12
1.40E-12
7.12E-13
9.95E-13
6.8SE-13
3.36E-12
5.38E-12
5.11E-12
3.83E-14
TOTAL 1.29E-04 2.02E-11
A-15
-------
W2I
WORKER OUST INHALATION
ton Watir Tnmt Sludg* (Lmdtlll)
G.1.68E-03
S- 1.00E+00
D(mrem) - G * S * C ORnh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal cana
e
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
vs) - G * S
OFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C ' RFInh
RFInh
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1 .90E-08
D
2.37E-06
3.53E-06
3.47E-06
1.71E-06
2.42E-06
1 .66E-06
8.06E-06
1.31E-05
1.21E-05
1.01E-07
R
3.78E-13
5.54E-13
5.24E-13
2.67E-13
3.73E-13
2.57E-13
1.26E-12
2.02E-12
1.92E-12
1.60E-14
TOTAL 4.85E-05 7.56E-12
A-16
-------
W2g
WORKER DUST INHALATION
ten Un*ml Procntlng WMf*
fr 1 .68E-03
S-1.00E+00
O(mrem) - 6 S C * DRnh
R(fatal cancan) - Q S
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E+01
1.00E+01
3.50E+01
3.50E+01
1.80E+00
OFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C ' RRnh
RFInh
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1.90E-08
D
3.95E-04
5.88E-04
S.06E-04
5.71 E-03
8.06E-05
1.94E-02
2.69E-02
7.64E-03
7.06E-03
3.63E-04
R
6.30E-1 1
9.24E-1 1
7.64E-1 1
8.90E-10
1 .24E-1 1
3.00E-09
4.20E-09
1.18E-09
1.12E-09
5.75E-1 1
TOTAL 6.86E-02 1.07E-08
A-17
-------
W2h WORKER - DUST INHALATION
tar: Oil t OM Scata/ Sludg*
G- 1.68E-03
S- 1.00E+00
D(mrem) . G S * C DRnh
R(fatal cancers) - G S C * RRnh
Nuclld* C DFlnh RRnh
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1 .55E+02
1.55E+02
1.55E+02
5.50E+01
5.50E+01
. .
. .
. .
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
. .
. .
. .
. .
. .
1 .SOE-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
- -
- -
. .
. -
2.45E-03
3.65E-03
2.24E-03
3.14E-02
4.44E-04
- -
- -
3.91 E-10
S.73E-10
3.39E-10
4.90E-09
6.84E-1 1
- -
- -
»
TOTAL 4.02E-02 6.27E-09
A-18
-------
W2I WORKER - OUST INHALATION
tor:
G. 1.68E-03
S- 1.00E+00
D(mrem) . G * S C * DRnh
R(fatal eancara) - G * S * C * RFInh
Nuclld* C DFInh RFInh
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.10E+02
1.10E+02
1.60E+02
3.00E-f01
1.10E+02
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
. -
- -
- -
- -
1.50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
-
1 .74E-03
2.59E-03
2.31 E-03
1.71E-02
8.87E-04
2.77E-10
4.07E-10
3.49E-10
2.67E-09
1.37E-10
- -
- -
TOTAL 2.47E-02 3.84E-09
A-19
-------
W3a WORKER INDOOR RADON INHALATION
ten Urmntum Orarburdton
O. 4.10E-06
S. 9.17E+08
DFr- 4.00E-06
R(fatal cancers) . Q S DFr
Nuclld* R
Ra-226 1.84E-02
TOTAL 1.84E-02
A-20
-------
W3b WORKER INDOOR RADON INHALATION
fen Phosphmtu Wm»t»
Q. 4.10E-06
S. 5.91 E+08
OR- 4.90E-06
R(fatal eanoara) - G S DFr
Nuelld* B
Ra-226 1.19E-02
TC3TAL 1.19E-02
A-21
-------
Wtt WORKER -INDOOR RADON INHALATION
& 4.10E-06
S- 6.77E+06
DFr- 4.90E-06
R(fatal cannn) - Q S * DFr
Nuelld* R _
Ra-226 1.36E-04
TOTAL 1.36E-04
A-22
-------
W3f WORKER-INDOOR RADON INHALATION
tar: Mfelw Tnmt Sludg* (LmndHII)
G. 4.10E-06
S- 5^5E*06
OFr- 4.90E-06
R(fatal cancers) - Q S DFr
Nuelld* R
Ra-226 1.18E-04
TOTAL 1.18E-04
A-23
-------
W3g WORKER - INDOOR RADON INHALATION
tar: MMrml Pncuulng Wnte
&4.10E-06
S- 1.35E+09
OFr- 4.90E-06
R(fatal cancers) - G * S DFr
Nuelld* R
Ra-226 2.71 E-02
TOTAL 2.71 E-02
A-24
-------
W3h WORKER INDOOR RADON INHALATION
ton Oil 4 GM Seal*/ Sludg»
G- 4.10E-06
S- 1.06E+09
DFr- 4.90E-06
R(fataJ cancers) . Q * S DFr
Nuelld* R
Ra-226 2.13E-02
TOTAL 2.13E-02
A-25
-------
W3I WORKER -INDOOR RADON INHALATION
tor; CMfftwiMl Wntu
Q.4.10E-06
S- 4.64E+09
DFr. 4.90E-06
R(fatal cancers) - G S DFr
Nuclld* R
Ra-226 9.32E-02
TOTAL 9.32E-02
A-26
-------
11*
ONSfTE INDIVIDUAL - DIRECT GAUUA EXPOSURE
ton Urmntum
fr 5.00E-01
S- 1.33E+06
D(mram) - Q * S * C * DFG
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal eanei
e
1 .66E+01
1.66E+01
2J7E4-01
I.OOE-t-00
1.00E+00
2.37E+01
1.00E4-00
2.37E+01
2.37E*01
1.20E+00
ra) . Q ' 3 * C ' RFG
ora
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
0.04E-05
8.88E-08
6.S6E-08
8.00E-08
6.41 E-08
1.67E-05
nra
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
9.44E-04
3.21E-01
2.63E+02
2.24E+01
6.01 E*00
1.40E-01
4.36E-03
1.26E-01
1.01E-01
1.33E+00
R
3.64E-10
1.21 E-07
1.02E-04
8.65E-06
2.33E-06
5.52E-08
1.73E-09
4.89E-08
3.94E-08
S.19E-07
TOTAL 2.94E+02 1.14E-04
A-27
-------
lib
ONSITE INDIVIDUAL DIRECT OAUUA EXPOSURE
ten P/KMp/ute MTMI»
& 5.00E-01
S-1.59E+05
D(mram) - G * S C DFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal cancc
c
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1 .30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
ire) - Q S '
DPB
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-OS
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
' C * RFC
BPO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.SOE-12
D
1.79E-03
6.11E-01
4.38E>02
7.23E+00
1.94E+00
9.18E-02
1 .41 E-03
3.94E-02
3.06E-02
3.98E-01
R
6.93E>10
2.31 E-07
1.71E-04
2.79E-06
7.51 E-07
3.62E-08
5.S8E-10
1 .53E-08
1.19E-08
1 .S5E-07
TOTAL 4.48E+02 1.75E-04
A-28
-------
He
ONSITE INDIVIDUAL . DIRECT GAMMA EXPOSURE
Phosphate F«rff/lz«r
G- S.OOE-01
S- 9.66E+04
(Xrnrarn) - G S C OFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fataleanet
C
1.80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1.60E-02
3.10E-04
1.70E-02
1.70E-02
8.60E-04
ire) - Q ' S '
OFO
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-OS
' C ' RFC
RPQ
3.30E-16
1.10E-13
6.SOE-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
7.43 E-08
2.53E-OS
2.02E-02
5.53E-03
1.48E-03
6.86E-05
9.82E-07
6.S7E-05
5.26E-05
6.94E-04
R
2.87E-14
9.56E-1 2
7.85E-09
2.13E-09
5.75E-10
2.70E-1 1
3.89E-13
2.55E-11
2.05E-11
2.70E-10
TOTAL 2.81 E-02 1.09E-08
A-29
-------
ltd
ONSffE INDIVIDUAL
Ian Goal Ath
DIRECT GAIUIA EXPOSURE
Q. 5.00E-01
S- 7.98E+04
(Xmrem) - Q 3 C DFG
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatalcance
C
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E*00
1.60E-01
ra) . Q * S '
DPS
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41E-08
1.67E-05
C ' RFQ
RPQ
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.SOE-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
2.39E-04
7.90E-02
2.47E*01
4.30E+01
6.49E*00
8.15E-03
5.SOE-03
1 .05E-02
8.44E-03
1.07E-01
R
9.22E-1 1
2.98E-08
9.60E-06
1 .66E-OS
2.51 E-06
3.21 E-09
2.18E-09
4.08E-09
3.29E-09
4.15E-08
TOTAL 7.44E+01 2.88E-OS
A-30
-------
11*
ONSITE INDIVIDUAL - DIRECT GAMMA EXPOSURE
tor: Mbtor Tn»t Sludg* {F»rtHU»r)
& S.OOE-01
S- 1.13E+05
D
-------
Ml
QUOTE MOIVIOUAL DIRECT QAIMIA EXPOSURE
Wafer Tnmt Sludg* (LfntHIH)
G. S.OOE-01
& 1.06E+05
D{mrem) - G * S * C DFG
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fataleancc
c
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
rs) . Q S '
era
8.S5E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
' C RFQ
RFQ
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.SOE-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
6.80E-06
2.31 E-03
2.12E+00
5.36E-02
1.44E+00
1.41E-05
1 .04E-05
2.54E-04
2.04E-04
4.43E-04
R
2.62E-12
8.75E-10
8.27E-07
2.07E-08
5.S7E-07
5.57E-12
4.13E-12
9.86E-1 1
7.95E-11
1.72E-10
TOTAL 3.62E+00 1.41E-06
A-32
-------
ONSITE INDIVIDUAL DIRECT OAIMIA EXPOSURE
Procuring Wm»t»
Q. 6.00E-01
^ 1.36E+05
(Xmrem) - G S * C * DFQ
R(fatal cancers) - G * S '
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
e
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E>01
1.00E+01
3.50E>01
3.50E+01
1.80E+00
DPO
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-OS
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-OS
' C ' RFQ
RTO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
O
1 .45E-03
4.95E-01
3.97E>02
2.29Ef02
6.15E+01
2.11E-01
4.46E-02
1 .90E-01
1.53E-01
2.04E+00
R
5.61E-10
1.87E-07
1 .55E-04
S.84E-OS
2.38E-05
8.33E-08
1.77E-08
7.38E-08
5.95E-08
7.96E-07
TOTAL 6.91 E+02 2.68E-04
A-33
-------
11 h ON8ITE WOMDUAI. - DIRECT OAUUA EXPOSURE
lor. Oil 4 OM Sccfa/ Studg»
-------
Ml
ONSIYE INDIVIDUAL - DIRECT GAMMA EXPOSURE
ten OfoOMnual Wm»t»
Q. S.OOE-01
S-1.30E+04
D(mram) » Q S ' C DFQ
R(fatal eaneora) - Q * S * C
RFG
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1.10E+02
1.10E+02
1.60E+02
3.00E+01
1.10E+02
- -
- .
ore
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
- -
- -
- -
- -
RPQ
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
- -
m m
~
D
6.1 1 E-04
2.08E-01
1.74E+02
6.57E+01
6.46E*01
- -
R
.36E-10
7.87E-08
6.76E-OS
2.54E-05
2.50E-05
- -
-
TOTAL 3.04E+02 1.18E-04
A-3S
-------
I2« ONSTl : INDIVIDUAL - INDOOR RAOON INHALATION
lor Ui nlum OvMfturtfM
Q. .34E-06
S- .17E+08
DFf- .OOE-06
R(fatal canct 3) . G S DFr
Nuelld* R
Ra-226 6.02E-02
TOTAL 6.02E-02
A-36
-------
I2b ONSITE MOIVIOUAL - INDOOR RADON INHALATION
tan Photphftt Wmmtm
Q. 1.34E-OS
S- 5.91 E+08
DR. 4.90E-06
R(fatal cancer*) . Q S DFr
Nuclld* R _
Ra-226 3.88E-02
TOTAL 3.88E-02
A-37
-------
I2e ONSITE INDIVIDUAL. INDOOR RADON INHALATION
tan Photph»t» Firtlllnr
O. 1.34E-05
S- 4.57E+04
DR. 4.90E-06
R(fatal cancan) . Q S * DFr
Nuclld* R
Ra-226 3.00E-06
TOTAL 3.00E-06
A-38
-------
I2d ONSITE INDIVIDUAL INDOOR RADON INHALATION
4*A
G. 1.34E-05
S- 6.77E+06
DFr. 4.90E-06
R(fatal cancers) - Q S * DFr
Nuclld* R
Ra-226 4.45E-04
TOTAL 4.45E-04
A-39
-------
12* ONStTE WOIVIDUAI. INDOOR RADON INHALATION
for: Wmttr Tnmt Sludgt
&1.34E-06
S. 1.56E4-07
DFr- 4.90E-06
R(fatal cancers) - Q S DFr
Nuelld* R
Ra-226 1.02E-03
TOTAL 1.02E-03
A-40
-------
I2f ONSTTE MOIVIDUAL INDOOR RAOON INHALATION
tan 1VMW Tnml Sludg* (Landnil)
Q.1.34E-05
S- 5.85E+06
OFtm 4.90E-06
R(fatal cancers) . Q S DFr
Nuclld* R
Ra-226 3.84E-04
TOTAL 3.84E-04
A-41
-------
|2g ONSITE INDIVIDUAL - INDOOR RADON INHALATION
ton Unurml Practising Wu»t»
&1.34E-05
S- 1.35E+09
OFr. 4.90E-06
R(fatal cancars) . Q S DFr
Nuelld* R
Ra-226 8.86E-02
TOTAL 8.86E-02
A-42
-------
I2h ONSITE INOIVIOUAL - INDOOR RADON INHALATION
tar; Off « CM Seata/ Sludg*
(W1.34E-05
S-1.06E+09
OR- 4.90E-06
R((atal cancers) . Q S DFr
Nuclld* H
Ra-226 6.96E-02
TOTAL 6.96E-02
A-43
-------
121 ONSITE INDIVIDUAL INDOOR RADON INHALATION
ton
&1.34E-05
S- 4.64E+09
DR. 4.90E-06
R(fatal cancan) - Q * S DFr
Nuelld* R
Ra-226 3.0SE-01
TOTAL 3.05E-01
A-44
-------
AVERAGE CPO - DIRECT GAIOIA EXPOSURE
Ion Uranium
Qi 1.52E-01
S- 1.33E+05
D(mrem) - Q * S * C * DFG
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatalcanct
C
1 .66E+01
1.66E+01
2.37E+01
1.00E+00
1.00E+00
2.37E+01
1.00E+00
2.37E+01
2.37E+01
1.20E*00
n) m Q S '
OPQ
8.S5E-10
2.91 E-07
1.67E-04
3.37E-04
0.04E-05
8.88E-08
6.56E-08
8.00E-08
8.41 E-08
1.67E-05
C * RFQ
RPQ
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
2.87E-04
9.77E-02
8.00E+01
6.81 E+00
1.83E*00
4.25E-02
1 .33E-03
3.83E-02
3.07E-02
4.05E-01
R
1.11E-10
3.69E-08
3.11 E-OS
2.63E-06
7.08E-07
1 .68E-08
5.26E-10
1.49E-08
1.20E-08
1 .58E-07
TOTAL 8.93E+01 3.47E-05
A-4 5
-------
I3b
AVERAGE CPO DIRECT GAMMA EXPOSURE
tan
G-1.52E-01
S- 1.59E+05
D(mrem) . Q * S C DFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal cancc
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
ITS) . Q S '
era
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-06
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
C * RFQ
RFO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.SOE-12
D
S.46E-04
1.86E-01
1.33E+02
2.20EfOO
5.90E-01
2.79E-02
4.28E-04
1.20E-02
9.30E-03
1.21E-01
R
2.11E-10
7.02E-08
5.18E-05
8.48E-07
2.28E-07
1.10E-08
1.70E-10
4.65E-09
3.63E-09
4.71 E-08
TOTAL 1.36E+02 5.31 E-05
A-46
-------
I3e
AVERAGE CPO DIRECT OAIOIA EXPOSURE
FirUUnr
O. 1.52E-01
S- 9.66E+04
D(niram) - O 3 C DFQ
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fataicancc
c
1 .80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1.60E-02
3.10E-04
1.70E-02
1.70E-02
8.60E-04
r» . Q S '
era
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-OS
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
' C * RFG
RPO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
2.26E-08
7.69E-06
6.13E-03
1 .68E-03
4.51 E-04
2.09E-05
2.99E-07
2.00E-05
1.60E-05
2. 11 E-04
R
8.72E-15
2.91 E-1 2
2.39E-09
6.49E-10
1.75E-10
8.22E-12
1.18E-13
7.74E-12
6.24E-12
8.21 E-1 1
TOTAL 8.54E-03 3.32E-09
A-47
-------
13d
AVERAGE CPO - DIRECT GAIOIA EXPOSURE
G- 1.52E-01
S- 7.98E+04
Dfmrem) - G * S C * DFG
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fataleancc
C
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
n) . Q * S '
DPS
8.55E-10
2.91 E-07
1 .67E-04
3.37E-04
9.04E-OS
8.88E-08
6.56E-08
8.00E-08
6.41E-08
1.67E-05
C ' RFG
RTO
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
7.26E-05
2.40E-02
7.49E+00
1.31E+01
1.97E+00
2.48E-03
1 .67E-03
3.20E-03
2.57E-03
3.24E-02
R
2.80E-11
9.07E-09
2.92E-06
5.05E-06
7.64E-07
9.76E-10
6.62E-10
1 .24E-09
1 .OOE-09
1 .26E-08
TOTAL 2.26E*01 8.75E-06
A-48
-------
13*
AVERAGE CPO - DIRECT GAIIUA EXPOSURE
ton Waltr Tract Slu4g»
G- 1.52E-01
S- 1.13E+05
(Xmrem) - G S C * DFG
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal cancc
C
4.00E-01
4.00E-01
6.40E-01
8.00 E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1.20E-03
ire) m Q S '
era
8.5SE-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
C * RFG
Rre
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
S.87E-06
2.00E-03
1.84E+00
4.63E-02
1.24E+00
1.22E-05
9.01 E-06
2.20E-04
1.76E-04
3.44E-04
R
2.27E-12
7.56E-10
7.15E-07
1.79E-08
4.81 E-07
4.81 E-1 2
3.57E-12
8.52E-1 1
6.87E-1 1
1.34E-10
TOTAL 3.13E+00 1.21 E-06
A-49
-------
131
AVERAGE CPO - DIRECT GAMMA EXPOSURE
for: W»tir Tnal Sludg* (Landfill)
Q.1.52E-01
S- 1.06E+05
Dpnram) - Q 3 C * DFQ
R(fatal cancan) . Q S C * RFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
2.07E-06
7.03E-04
6.46E-01
1.63E-02
4.37E-01
4.29E-06
3.17E-06
7.73E-05
6.20E-05
1.35E-04
7.98E-13
2.66E-10
2.51 E-07
6.28E-09
1 .69E-07
1.69E-12
1.26E-12
3.00E-11
2.42E-1 1
5.24E-1 1
TOTAL 1.10E+00 4.27E-07
A-60
-------
I3g
AVERAGE CPO- DIRECT GAMMA EXPO
for. MTfMraf Proofing fflul*
Q. 1.52E-01
S- 1.36E+05
Dfmrarn) - G S C * DFQ
R(fatal cancore) . Q S C
RFQ
Nuelldi
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
2.50E+01
2.50E+01
3.50E+01
1.00E*01
1.00E>01
3.50E*01
1.00E4-01
3.50Ef01
3.50E>01
1.80E+00
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-OS
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-OS
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
4.42E-04
1.50E-01
1.21E+02
6.97E-f01
1.87E+01
6.42E-02
1 .36E-02
5.79E-02
4.64E-02
6.21 E-01
1.71E-10
5.68E-08
4.70E-OS
2.69E-05
7.24E-06
2.53E-08
5.37E-09
2.24E-08
1.81 E-08
2.42E-07
TOTAL 2.10E+02 8.15E-05
A-51
-------
I3h
AVERAGE CPQ DWECT GAMMA EXPOSURE
ten Oil « GM Scita/ Sludg*
&1.52E-01
& 1.20E+OS
D(mrani) . Q S * C * DFQ
Rffatti cancan) - Q * S * C RFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1 .55E+02
1.55E+02
1 .55E+02
5.50E+01
5.50E+01
8.5SE-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
- -
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
- -
2.42E-03
8.23E-01
4.72E+02
3.38E+02
9.07E+01
- -
- -
- -
9.33E-10
3.11 E-07
1.84E-04
1.30E-04
3.51E-05
-
-
-
- -
TOTAL 9.02E+02 3.50E-04
A-S2
-------
131 AVERAGE CPO- DIRECT QAUUA EXPOSURE
ten OMMwnwl Wm»t»
Q. 1.52E-01
S- 1.30E+04
0(mram) - Q * S * C * DFG
R(fatal cancan) - Q S * C RFQ
Nuelldi
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.10E-I-02
1.10E+02
1 .60E+ 02
3.00E+01
1.10E+02
. .
. .
8.55E-10
2.91E-07
1.67E-04
3.37E-04
9.04E-05
- -
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
- -
- -
- -
1 .86E-04
6.33E-02
5.28E+01
2.00E+01
1.96E+01
7.17E-11
2.39E-08
2.06E-05
7.71 E-06
7.61 E-06
- -
-
- -
-
TOTAL 9.25E+01 3.59E-05
A-53
-------
14*
AVERAGE CPO INHALATION OF CONTAMINATED DUST
Ion Unnlum Orarfeurdfen
& 2.36E+03
& 6.90E-07
D(mrem) . G S * C * DRnh
R(fatal cancers) . Q S
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1 .66E+01
1.66E+01
2.37E+01
1.00E+00
1.00E+00
2.37E+01
1.00E+00
2.37E+01
2.37E+01
1.20E*00
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C * RRnh
RFInh
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1 .90E-08
D
2.54E-04
3.78E-04
3.32E-04
5.54E-04
7.82E-06
1 .27E-02
2.61 E-03
5.02E-03
4.63E-03
2.34E-04
R
4.0SE-1 1
5.95E-11
5.02E-11
8.63E-1 1
1.21E-12
1.97E-09
4.07E-10
7.72E-10
7.33E-10
3.71 E-11
TOTAL 2.67E-02 4.16E-09
A-54
-------
I4b
AVERAGE CPO
tor
INHALATION OF CONTAMINATED DUST
G. 2.36E+03
S- 2.83E-07
O(mrem) - G * S * C * DFlnh
R(fataJ cancers) - G S C '
RFinh
Nuclld*
DFInh
RFlnh
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
9.40E-03
1 .40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1 .90E-08
1 .66E-04
2.47E-04
1 .90E-04
6.13E-05
8.66E-07
2.87E-03
2.89E-04
5.38E-04
4.81 E-04
2.40E-05
2.64E-1 1
3.88E-1 1
2.87E-1 1
9.56E-12
1.33E-13
4.43E-10
4.S1E-11
8.28E-1 1
7.61 E-11
3.81 E-1 2
TOTAL 4.86E-03 7.54E-10
A-55
-------
I4c AVERAGE CPO - INHALATION OF CONTAMINATED DUST
Pnosptete Ftrtfltrw
O. 2.36E+03
S- 6.90E-07
D(mrem) - 0 ' S * C * DFInh
R(tatal cancer*) . Q S C RHnh
Nuelld* C DFInh RFInh
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1.60E-02
3.10E-04
1.70E-02
1.70E-02
8.60E-04
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1 .90E-08
2.76E-08
4.10E-08
3.50E-08
1 .88E-07
2.66E-09
8.60E-06
8.08E-07
3.60E-06
3.32E-06
1 .68E-07
4.40E-15
6.4SE-15
5.29E-15
2.93E-14
4.10E-16
1.33E-12
1.26E-13
5.54E-13
5.26E-13
2.66E-14
TOTAL 1.68E-OS 2.61 E-12
A-66
-------
I4d
AVERAGE CPO INHALATION OF CONTAMINATED DUST
G. 2.36E+03
S- 1.32E-07
D(mrem) - G * S * C * DRnh
R(fatal cancers) - G * S
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C * RFlnh
RRnh
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1.90E-08
D
2.05E-OS
2.97E-05
9.91 E-06
3.39E-04
2.69E-06
2.36E-04
1.05E-03
1.34E-04
1 .23E-04
5.98E-06
R
3.27E-12
4.66E-12
1.50E-12
5.28E-1 1
4.15E-13
3.65E-1 1
1.64E-10
2.06E-11
1.95E-11
9.47E-13
TOTAL 1.95E-03 3.04E-10
A-57
-------
141
AVERAGE CPO INHALATION OF CONTAMINATED DUST
Ion W»t»r Tnml Sludg* (F*rtHU»r)
& 2.36E+03
S- 8.28E-07
D(mrem) . Q S C * OFInh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatal eanoi
C
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1.20E-03
n) . 0 S
OFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1 .30E-01
1.20E-01
1.20E-01
C ' RFlnh
RFInh
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1 .90E-08
D
7.35E-06
1 .09E-05
1.08E-05
5.32E-06
7.50E-06
5.16E-06
2.50E-OS
4.06E-05
3.75E-05
2.81 E-07
R
1.17E-12
1.72E-12
1.63E-12
8.29E-13
1.16E-12
7.97E-13
3.91 E-1 2
6.25E-12
5.94E-12
4.46E-14
TOTAL 1.50E-04 2.34E-11
A-58
-------
141
AVERAGE CPO INHALATION OF CONTAUN/ "ED DUST
Ion Wmltr Tnml Sludg» (LandHII)
G. 2.36E+03
S- 8.95E-07
D(mrem) - Q * S * C * DRnh
Nueli- i
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R((atal canes
e
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
n) - Q S
OFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C * RRnh
RRnh
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1.90E-08
D
2.98E-0*
4.44E-0'
4.36E-0-
2.15E-0'
3.04E-0-
2.09E-0'
1.01E-0
1 .65E-0
1 .52E-0
1.27E-0
R
4.75E-13
6.97E-13
6.59E-13
3.36E-13
4.69E-13
3.23E-13
1.58E-12
2.53E-12
2.41 E-1 2
2.01 E-14
TOTAL 6.10E-0 9.51 E-12
A-59
-------
I4g
AVERAGE CPO - INHALATION OF CONTAIONATEO DUST
tor MTmraf Practising Mtote
G. 2.36E+03
S- 6.85E-07
D(mrem) - Q S C * DRnh
R(tatal cancers) . Q S
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1 .OOE+01
3.50E+01
1.00E+01
3.50E+01
3.50E+01
1.80E*00
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
C RFJnh
RRnh
1 .50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1.90E-08
D
3.80E-04
5.66E-04
4.87E-04
5.50E-03
7.76E-OS
1 .87E-02
2.59E-02
7.36E-03
6.79E-03
3.49E-04
R
6.06E-1 1
8.89E-1 1
7.36E-1 1
8.57E-10
1.20E-11
2.89E-09
4.04E-09
1.13E-09
1 .08E-09
5.53E-1 1
TOTAL 6.60E-02 1.03E-08
A-60
-------
Uh AVERAGE CPO INHALATION OF CONTAMINATED DUST
ton Oil * OM Scata/ Sludg»
fr 2.36E+03
S- 6.39E-08
O(mrem) - Q S C DFlnh
R(fatal cancan) - G S C RFInh
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1.55E+02
1.55E+02
1.55E+02
5.50E+01
5.50E+01
- -
- -
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
RFInh
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
-
D
2.20 E-04
3.27E-04
2.01 E-04
2.82E-03
3.98E-05
R
3.51 E-11
5.14E-11
3.04E-1 1
4.40 E- 10
6.14E-12
" "
TOTAL 3.61 E-03 5.63E-10
A-61
-------
141 AVERAGE CPQ- INHALATION OF CONTAMNATEO OUST
for: OMfftwiMl Wut»
G. 2.36E+03
S-6.01E-08
D(mrem) - Q * S C * DFlnh
R(fatal cancan) - Q * S * C * RFlnh
Nuclld* C OFInh RFInh
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.10E+02
1.10E+02
1.60E+02
3.00E+01
1.10E+02
. .
. .
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
. .
- .
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
- .
^~,
- -
1 .47E-04
2.18E-04
1 .95E-04
1 .45E-03
7.49E-05
-
- -
2.34E-1 1
3.43E-11
2.95E-1 1
2.26E-10
1.15E-11
-
- -
- -
- -
TOTAL 2.08E-03 3.24E-10
A-62
-------
ISm AVERAGE CPQ-OOWNWMO EXPOSURE TO RADON
iOfS IMVAMIfll OWfftlirawfV
G- 2.95E-01
S- 2.97E+00
OR- 4.80E-07
R(fatal cancers) » Q S DFr
Nuelld* R
Ra-226 4.29E-07
TOTAL 4.29E-07
A-63
-------
I5b AVERAGE CPQ-OOWNWMD EXPOSURE TO RAOON
tars PAMptef* Wmrnt*
& 2.95E-01
S- 1.96E+00
DFr- 4.90E-07
R(fatal cancers) - Q S * DFr
Nuelld* R
Ra-226 2.83E-07
TOTAL 2.83E-07
A-64
-------
ISc AVERAGE CPO-DOWNWIND EXPOSURE TO RAJ ON
tar: Pho»ph*t» FwtHlnr
G» 2.85E-01
S- 3.76E-05
DFf- 4.90E-07
R(fatal cancan) « Q * 3 * DFr
Nuelld* R
Ra-226 5.44E-12
TOTAL 5.44E-12
A-65
-------
134 AVERAGE CPO-OOWNWMD EXPOSURE TO RADON
Q. 2.96E-01
S- 2.09E-02
OR- 4.90E-07
R(tatal canem) . Q * S * DFr
Nuelld* R
Ra-226 3.02E-09
TOTAL 3.02E-09
A-66
-------
IS* AVERAGE CPO-OOWNWMD EXPOSURE TO RADON
ton W»t»r Tnmt Sludgm (FwtlUnr)
& 2.95E-01
S- 1.10E-02
DR. 4.90E-07
R(fatal cancan) - 0 S DFr
Nuelld* R
Ra-226 1.59E-09
TOTAL 1.50E-00
A-67
-------
ISf AVERAGE CPO-OOWNWMO EXPOSURE TO RADON
ton Wuttr Tmt Sludg* (Lutdttllt
G. 2.05E-01
S- 1.76E-02
DFr. 4.90E-07
R(fatai cancers) - Q S * DFr
Nuelld* R
Ra-226 2.54E-09
TOTAL 2.54E-09
A-68
-------
I5g AVERAGE CPO-DOWNWIND EXPOSURE TO RADON
Ion IHiMrml Procuring Wm»t»
& 2.95E-01
S- 4.35E+00
DFr- 4.90E-07
R(fatal cancer*) . Q S * DFr
Nuellda R
Ra-226 6.29E-07
TOTAL 6.29E-07
A-69
-------
I3h AVERAGE CPO-DOWNWIND EXPOSURE TO RADON
tan Of/ « OM Scita/ Sludg*
G- 2.95E-01
S- 3.19E+00
DFr- 4.90E-07
R(fatal cancers) - G * S * DFr
Nuclld* H
Ra-226 4^1 E-07
TOTAL 4.61 E-07
A-70
-------
ISI AVERAGE CM-OOWNWMO EXPOSURE TO RADON
ton
0. 2.95E-01
S- 1.31E+01
DFr- 4.90E-07
R(fatal canon) . Q * S * DFr
Nuelld* R
Ra-226 1.89E-06
TOTAL 1.80E-06
A-71
-------
I6b
MVKMWM^ W^^M ~ r ^v^v^rva^ »^ «* « ^-^V^B^WV .- -- - - -
ten Photphf* IMMte
Q- 8.48E-01
3- 2 J5E+06
CKmrem) . Q S C * DFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fatalcance
C
2.64E+01
2.64E«01
3.30E*01
2.70E-01
2.70E-01
UOE+01
2.70E-01
6.20E*00
6.00E*00
3.00E-01
ra) - 0 * S
era
8.55E-10
2.01 E-07
1.67E-04
3.37E-04
0.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
' C RFQ
f*Q
3.30E-16
1.10E-13
6.SOE-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
4.50E-02
1.53E*01
1.10E*04
1.8lEf02
4.86E*01
2.30E+00
3.53E-02
9.88E-01
7.66E-01
9.98E+00
R
1 .74E-08
5.79E-06
4.27E-03
6.99E-05
1 .88E-05
9.07E-07
1 .40E-08
3.83E-07
2.99E-07
3.89E-06
TOTAL 1.12E+04 4.37E-03
A-72
-------
I6d
AVERAGE CPO - EXPOSURE TO NORM IN BUILDING MATERIALS
Q. 8.48E-01
s- 1.20E+06
D(mram) - Q 3 C * OFQ
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
R(fataleanct
c
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
m) . Q * S '
DPQ
8.SSE-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-05
' C * RFG
RPQ
3.30E-16
1.10E-13
8.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
D
6.09E-03
2.01 E+00
6.29E*02
1.10E+03
1.66E*02
2.08E-01
1.40E-01
2.60E-01
2.15E-01
2.72E+00
R
2.3SE-09
7.61 E-07
2.45E-04
4.23E-04
6.41 E-OS
8.19E-08
5.56E-08
1.04E-07
8.40E-08
1 .06E-06
TOTAL 1.90E+03 7.34E-04
A-73
-------
I6g
ton Unerml Procuring Wm»
Q. 8.48E-01
S- 2.00E+06
D(mrem) . Q S C * DFQ
R(fatal cancers) - G * S '
Nuclid*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E*01
3.50E*01
1.00E*01
3.50E4-01
3.50E+01
1.80E*00
OPB
8.55E-10
2.91 E-07
1.67E-04
3.37E-04
9.04E-05
8.88E-08
6.56E-08
8.00E-08
6.41 E-08
1.67E-OS
' C ' RFC
RP9
3.30E-16
1.10E-13
6.50E-11
1.30E-10
3.50E-11
3.50E-14
2.60E-14
3.10E-14
2.50E-14
6.50E-12
O
3.63E-02
1.23E+01
9.91 E*03
5.72E+03
1.53E+03
5.27EfOO
1.11E+00
4.75E+00
3.80E+00
5.10E+01
R
1 .4OE-08
4.66E-06
3.86E-03
2.20E-03
5.94E-04
2.08E-06
4.41 E-07
1 .84E-06
1 .48E-06
1 .98E-05
TOTAL 1.72E+04 6.69E-03
A-74
-------
17*
AVERAGE CPO - MOESHON OF
DRMKINQ WATER FROM A CONTAMWATED WELL
tan Urmnlum Orarburriwi
G. 7.40E+00
S- 4.67E+04
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
D(mr m) . (Q S C DRng (1-«xp» / R
R(fai I cancers) . (Q S * C RFIng (1-exp)) /
1.6 i+01
1.6 =«-01
2.3 =+01
1.0 EfOO
1.0 E+00
2.3 S+01
1.0 5+00
2.3 £+01
2.3 =+01
1.2 =+00
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-1 1
3.90E-11
4.20E-11
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E+02
8.18E+04
8.18E+04
2.46E+02
2.46E+02
2.46E+02
R
1-«xp
3.40E-05
3.40E-05
3.40E-05
3.40E-OS
3.40E-05
3.40E-05
3.40E-05
3.40E-OS
3.40E-05
3.40E-05
O
1.35E-03
2.14E-03
1.47E-03
5.75E-08
6.69E-05
1.87E-06
3.88E-07
3.17E-04
2.83E-04
1.55E-OS
R
3.33E-10
2.26E-10
8.91 E-1 5
1.05E-11
2.89E-13
6.03E-14
4.87E-11
4.41 E-1 1
2.41 E-1 2
TOTAL 5.65E-03 8.72E-10
A-75
-------
I7b
AVERAGE CPO - MGESTION OF
DRINKING WATER FROM A CONTAMINATED WELL
tar Phetphmtf Wm»t»
Q. 7.40E+00
S- 7.72E+03
D(mrem) - (G * S * C * DFIng * (1-exp)) / R
R(tatal cancers) . (Q S * C * RFlng * (1-exp)) / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1 .30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFlng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.45E+03
2.45E+03
1-«xp
3.50E-02
3.50E-02
3.50E-02
3.50E-02
3.SOE-02
3.50E-02
3.50E-02
3.50E-02
3.50E-02
3.SOE-02
D
3.67E-02
5.81 E-02
3.50E-02
2.64E-07
3.08E-04
1.75E-05
1.78E-06
1.42E-03
1.22E-03
6.61 E-05
R
. S1E-09
< 03E-09
' 39E-09
09E-14
85E-11
. 70E-12
. 77E-13
. 18E-10
91E-10
03E-11
TOTAL
1.33E-01
OSE-08
A-76
-------
I7e
AVERAGE CPQ - MQESTION OF
DRMKWQ WATER FROM A CONTAMINATED WELL
Phemphmtf Ftrtf/tnr
Q. 7.40E+00
S> 2.18E+02
D(mrem) . (Q S C DFIng (1-exp)) / R
R(fataJ cancers) - (Q * S * C * RPIng * (1-«xp)) / R
Nuclld
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1 .80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1.60E-02
3.10E-04
1.70E-02
1.70E-02
8.60E-04
DFIng
1.BOE-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E\03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.45E+03
2.45E*03
1-««p
8.80E-03
8.80E-03
8.80E-03
8.80E-03
8.80E-03
8.80 E-03
8.80E-03
8.80E-03
8.80E-03
8.80E-03
0
1 .78E-08
2.81 E-08
1.88E-08
2.36E-12
2.76E-09
1.53E-10
1.45E-11
2.76E-08
2.46E-08
1 .35E-09
R
4.37E-1 S
2.90E-1 5
3.66E-1 3
4.33E-1 6
2.36E-1 7
2.26E-13
4.24E-1 5
3.84E-1 5
2.09E-1 6
TOTAL
1.21E-07 1.87E-14
A-77
-------
174
MGESTIONOF
A CONTAMINATED WELL
AVERAGE CPO
ORMKINQ WATER
for: Co* Adi
Q. 7.40E+00
S- 1.07E+04
D(mrwn) - (Q * S * C * DRng (1-exp)) / R
Rftatal cancers) . (Q S C RHng (1-«xp)) / R
PO-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
OFInfl
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RRna
2.90E-10
8.40E-10
2.00E-10
6.20E-1 1
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
5.46E+02
5.46E+02
4.10E+02
1.64E*04
4.10E+02
1.64E-f04
1.64E+04
2.74E+02
2.74E+02
2.74E+02
1-.XP
6.70E-02
6.70E-02
6.70E-02
6.70E-02
6.70E-02
6.70E-02
6.70E-02
6.70E-02
6.70E-02
6.70E-02
D
1.29E-01
3.57E-01
6.22E-02
4.14E-04
3.26E-02
4.09E-04
1 .83E-03
1 .79E-02
1.60E-02
8.36E-04
R
1 .97E-08
5.55E-08
9.57E-09
6.42E-1 1
5.12E-09
6.32E-11
2.85E-10
2.75E-09
2.49E-09
1.30E-10
TOTAL 6.18E-01 9.57E-08
A-78
-------
17*
AVERAGE CPO - MGESTION OF
DRWKMO WATER FROM A CONTAMINATED WELL
Mfefw r/Ml Sludg» (Fwtlllnr)
Q. 7.40E+00
S- 2.58E+02
O(mrem) - (Q * S * C DFlng (1*xp)) / R
R(fatal cancers) - (G * S * C * RFlng * (1-exp)) / R
Nuclid*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
4.00E-01
4.00E-01
6.4OE-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1.20E-03
DFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFlng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.45E+03
2.45E+03
1-«P
8.70E-03
8.70E-03
8.70E-03
8.70E-03
8.70E-03
8.70E-03
8.70E-03
8.70E-03
8.70E-03
8.70E-03
D
4.62E-06
7.31 E-06
5.64E-06
6.50E-1 1
7.S9E-06
8.93E-1 1
4.39E-10
3.04E-07
2.71 E-07
2.20E-09
R
7.06E-13
1.14E-12
8.68E-13
1.01E-17
1.19E-12
1.38E-17
6.82E-17
4.66E-14
4.23E-14
3.42E-16
TOTAL 2.57E-OS 3.99E-12
A-79
-------
171
AVERAGE CPO MGEST1ON OF
ORINKWO WATER FROM A CONTAMINATED WELL
tor: W»t»r Tnmt Sludg* (LfadlUI)
fr 7.40E+00
S- 8.50E+03
O(mrem) - (G * S C DFIng * (1-exp» / R
R(fatal cancers) . (Q S * C * RFIng (1-exp)) / R
Nuelldi
OFIna
RFIna
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1 .40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.45E+03
2.45E+03
2.20E-04
2.20E-04
2.20E-04
2.20E-04
2.20E-04
2.20E-04
2.20E-04
2.20E-04
2.20E-04
2.20E-04
1 .44E-06
2.28E-06
1.76E-06
2.03E-1 1
2.37E-06
2.79E-1 1
1.37E-10
9.49E-08
8.47E-08
7.63E-10
2.20E-13
3.55E-13
2.71 E-1 3
3.15E-18
3.73E-13
4.31 E-1 8
2.13E-17
1.46E-14
1.32E-14
1.19E-16
TOTAL 8.04E-06 1.25E-12
A-80
-------
I7g
AVERAGE CPQ - MOE9TION OF
DfUNNNQ WATER FROM A CONTAMINATED WELL
lor: Iff/Mm* Proc*M4ng Wm»t»
& 7.40E+00
S- 3.06E+05
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
D(mrem) . (Q 8 * C DFlng (1-exp)) / R
R(fatal cancer*) . (Q S C RRng * (1-«xp» /
C DFIna RFIna R
2.50£+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E+01
1.00E+01
3.50E>01
3.50E*01
1.80E>00
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
2.74E+02
4.92E+02
2.46E+02
8.18E>04
2.46E+02
8.18E+04
8.18E+04
2.46E>02
2.46E*03
2.46E>02
R
1-«ip
2.00E-06
2.00 E-06
2.00E-06 !
2.00E-06 :
2.00 E-06 :
2.00E-06
2.00E-06
2.00E-06
2.00E-06
2.00E-06 >
35E-04
24E-03
38E-04
21E-07
58E-04
07E-06
49E-06
80E-04
61E-05
95E-06
1.20E-10
1.93E-10
1.29E-10
3.43E-14
4.0SE-11
1.65E-13
2.33E-13
2.77E-11
2.51 E-12
1.39E-12
TOTAL : 33E-03 5.15E-10
A-81
-------
I7H AVERAGE CPO-MGESnON OF
ORIMONO WATER FROM A CONTAMINATED WELL
ton Off « OM Safe/ Studg»
& 7.40E+00
S- 3.96E+04
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
D(mram) - (Q S C * DFIng * (1-axp)) / R
R(tatal cancers) - (Q * S * C RFlng * (1-axp)) /
C DFIng RFlng R
1.55E+02
1.55E+02
1.55E*02
5.50E+01
5.SOE+01
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
m
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
5.46E+02
5.46E>02
1.36E+04
1.36E>04
1.36E*04
R
1-.KP
3.00E-03
3.00E-03
3.00E-03
3.00E-03
D
4.74E-01
1.3SE*00
1.30E-02
1.42E-03
4.98E-03
R
7.24E-08
2.10E-07
2.00E-09
2.20E-10
7.82E-10
TOTAL 1.84E+00 2.85E-07
A-82
-------
171 AVERAGE CPQ - MGESTON OF
DRINKING WATER FROM A CONTAMINATED V -LL
tor tteofftwimf Wmmt»
O> 7.40E+00
S- 9.25E+04
D(mrem) - (G S C DFlng * (1-exp)) / R
R((atal cancer*) . (Q S * C * RRng * (1-exp)) /
Nuelld* C DFIng RFlng
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.10E+02
1.10E+02
1.60E+02
3.00E+01
1.10E+02
- .
. .
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
- -
- -
- -
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
- -
- -
- -
- -
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E+02
-
5.80E-05
5.80E-05
5.80E-OS
5.80E-05
5.80E-05
-
»
- -
3.03E-02
4.79E-02
3.36E-02
S.82E-06
2.49E-02
-
-
4.62E-09
7.46E-09
5.16E-09
9.03E-13
3.91 E-09
-
-
TOTAL 1.37E-01 2.11E-08
A-83
-------
9m
AVQ CPO - MGESnON OF FOODSTUFFS
CONTAMINATED BY WELL WATER
tor Urmnlum Orarfturriwi
G> 2.00E+01
S. 4.67E+04
1-exp-3.40E-05
D(mrem) - (Q S * C * (Uw - 0.37) 'DFIng (1-exp)) / R
R((ataJ cancers) - (G S C (Uw - 0.37) * RFIng (1-exp)) /
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
C
1 .66E+01
1.66E+01
2.37E+01
1 .OOE+00
1.00E+00
2.37E+01
1 .OOE+00
2.37E+01
2.37E4-01
1.20E>00
DHitfl
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFlnfl
2.90^-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.74E+02
4.92E>02
2.46E*02
8.18E+04
2.46E+02
8.18E+04
8.18E+04
2.46E+02
2.46E+02
2.46E+02
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
D
2.09E-03
3.32E-03
2.28E-03
8.84E-08
1.03E-04
2.90E-06
5.96E-07
4.33E-04
3.87E-04
2.12E-05
R
.20E-10
S.16E-10
3.51 E-10
1.37E-14
1.62E-11
4.48E-13
9.28E-14
6.66E-1 1
6.04E-1 1
3.29E-12
TOTAL 8.64E-03 1.33E-09
A-84
-------
I8b
AVO CPO NOESTION OF FOODSTUFFS
GOMTAUMATED BY WELL WATER
Ion Phoiphat* W»mt»
& 2.00E+01
S- 7.72E+03
1-«xp-3.50E-02
D(fflrem) - (Q S C * (Uw - 0.37) 'OFIng * (1-«xp)) / R
R(fatal cancer*) - (Q * S C (Uw - 0.37) RRng (1-exp)) / R
f*O-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1 .30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
1.90E-03
5.40E-03
1 .30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
HFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E*03
8.18Ef05
8.18E*05
2.4SE+03
2.45E+03
2.45E*03
Uw
9.43 E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
D
5.69E-02
8.99E-02
5.42E-02
4.06E-07
4.74E-04
2.71 E-05
2.74E-06
1.94E-03
1 .67E-03
9.04E-05
R
1.40E-08
8.34E-09
6.29E-14
7.46E-1 1
4.18E-12
4.26E-13
2.98E-10
2.61 E-10
1.41E-11
TOTAL 2.05E-01 3.17E-08
A-85
-------
I8e
AVO CPO - MOESTION OF FOODSTUFFS
CONTAMINATED BY WELL WATER
Phosphate FtortfflMr
Q. 2.00E+01
S- 2.18E+02
1-«xp- 8.80E-03
D(mram) - (O S * C (Uw - 0.37) 'OFIng (1-exp)) / R
R(fatal cancan) - (Q * S C * (Uw - 0.37) RRng ' (1-exp)) / R
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1.80E-03
1 .80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1 .70E-02
1.70E-02
8.60E-04
DHna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
S.50E-04
2.70E-03
2.80E-04
2.SOE-04
2.70E-04
RFInfl
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E*05
2.46E*03
8.18E+05
8.18E*05
2.45E+03
2.45E>03
2.45E+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
D
2.7SE-08
4.35E-08
2.92E-08
3.63E-12
4.24E-09
2.37E-10
2.23E-1 1
3.77E-08
3.37E-08
1.84E-09
R
6.77E-15
4.49E-15
5.63E-19
6.67E-16
3.66E-17
3.47E-18
5.79E-15
S.25E-15
2.86E-16
TOTAL
1.78E-07 2.75E-14
A-86
-------
I8d
AVO CPO - MGESTON OF FOODSTUFFS
CONTAMMATED BY WELL WATER
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
Q. 2.00E+01
S- 1.07E+04
1-exp- 6.70E-02
D(mram) - (Q * S C * (Uw - 0.37)
R(fatal cancers) - (Q S C (Uw -
C DFlna RFIng
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
1.60E-01
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
S.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-1 1
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
DFIng * (1-exp)) / R
0.37) * RFIng * (1-exp))
R Uw
5.46E+02
5.46E+02
4.10E+02
1.64E+O4
4.10E+02
1.64E+04
1.64E+04
2.74E+02
2.74E+02
2.74E*02
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
/ R
D
2.00E-01
5.53E-01
9.64E-02
6.37E-04
5.01 E-02
6.34E-04
2.82E-03
2.45E-02
2.18E-02
1.14E-03
R
3.05E-08
8.59E-08
1.48E-08
9.87E-11
7.88E-09
9.79E-1 1
4.39E-10
3.76E-09
3.41 E-09
1.78E-10
TOTAL 9.51 E-01 1.47E-07
A-87
-------
IB*
AVO CPO MQEST10N OF
TUFFS
CONTAMINATED BY WELL WATER
ton Mfefw Tnmt Sludg* (Fmrtlllxmr)
Q- 2.00E+01
S- 2.58E+02
1-exp-8.70E-03
D(mrem) - (Q S C * (Uw - 0.37) 'OFlng (1-exp)) / R
R(fatal cancers) . (Q S * C * (Uw - 0.37) * RFing (1-exp)) /
Nuelld*
F*o-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1.20E-03
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E*03
2.45E+03
2.4SE4-03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
O
7.16E-06
1.13E-05
8.74E-06
9.99E-1 1
1.17E-05
1.38E-10
6.74E-10
4.15E-07
3.71 E-07
3.00E-09
R
1.09E-12
1.76E-12
1.34E-12
1.55E-17
1.83E-12
2.14E-17
1.05E-16
6.38E-14
S.79E-14
4.67E-16
TOTAL 3.97E-05 6.15E-12
A-88
-------
I8f
AVO CPO MGESTWN OF FOODSTUFFS
CONTAMINATED BY WELL WATER
for: Watir Tnat Sludg» (LindUH)
G. 2.00E+01
S- 8.50E+03
1-exp- 2.20E-04
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
D(mrem) - (Q * S C * (Uw - 0.37)
R(fatal cancan) - (G S C (Uw -
C DFlng RFIng
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
S.OOE-04
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.SOE-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-1 1
DFlng (1-exp)) / R
0.37) RRng (1-exp))
R Uw
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E>05
8.18E+05
2.45E*03
2.45E+03
2.45E+03
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
/ R
D
2.24E-06
3.54E-06
2.73E-06
3.12E-11
3.65E-06
4.32E-11
2.11E-10
1.30E-07
1.16E-07
1 .04E-09
R
3.41 E-1 3
5.50E-13
4.20E-13
4.84E-18
5.73E-13
6.68E-18
3.28E-17
1.99E-14
1.81 E-1 4
1.62E-16
TOTAL 1.24E-05 1.92E-12
A-89
-------
ISfl
AVO CPO MGESTION OF FOODSTUFFS
CONTAMINATED BY WELL WATER
Ion MOOT* Pnc»»tlng Wnt»
Q. 2.00E+01
S- 3.06E+05
1-exp- 2.00E-06
D(mrem) - (Q S * C * (Uw - 0.37) 'DFlng * (1-exp)) / R
R(fatal cancers) - (O * S C (Uw - 0.37) RRng (1-exp)) /
Nuelld*
PO-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E+01
1.00E+01
3.50E*01
3.50E+01
1.80E+00
DFIng
1.90E-03
5.40E-03
1 .30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFInfl
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.74£+02
4.92E+02
2.46E+02
8.18E*04
2.46E+02
8.18E+04
8.18E+04
2.46E4-02
2.46E+03
2.46E+02
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
D
1.22E-03
1.92E-03
1.30E-03
3.41 E-07
3.96E-04
1.65E-06
2.30E-06
2.47E-04
2.20E-05
1.22E-05
R
1.86E-10
2.99E-10
2.00E-10
5.28E-14
6.23E-11
2.55E-13
3.58E-13
3.79E-1 1
3.44E-12
1.90E-12
TOTAL
S.12E-03 7.91 E-10
A-90
-------
I8h AVOCPO-WGEST1ON OF FOODSTUFFS
COMTAUMATEO BY WELL WATER
for; Oil « CM Scata/ Sludg*
Q> 2.00E+01
8- 3.96E+04
1-exp-3.00E-03
D(mram) - (Q S C * (Uw - 0.37) 'DFlng * (1-exp)) / R
R(fatal cancan) . (Q S C (Uw - 0.37) * RFIng (1-exp)) /
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
e
1.55E+02
1.5SE+02
1.55E+02
5.50E+01
5.50E+01
. .
- .
. .
DFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
. -
R
5.46E+02
5.46E*02
1.36E*04
1.36E+04
1.36E*04
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
D
7.34E-01
2.09E+00
2.02E-02
2.19E-03
7.65E-03
-
R
1.12E-07
3.25E-07
3.10E-09
3.39E-10
1.20E-09
"
" "
"
TOTAL 2.85E+00 4.41 E-07
A-91
-------
181 AVOCPO-WOESTION OF FOODSTUFFS
CONTAMMATED BY WELL WATER
tor G*00MniMf Wmtt»
& 2.00E+01
S- 9.25E+04
1-exp- 5.80E-06
D(mrem) - (Q * S C * (Uw - 0.37) *DRng * (1-exp)) / R
R(fataJ cancers) - (Q S C (Uw - 0.37) * RRng * (1-exp)) /
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1.10E+02
1.10E+02
1.60E+02
3.00E+01
1.10E+02
. .
. -
. .
- -
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
*
- -
RFInfl
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
R
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E>02
- -
- -
-
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
- -
- -
- -
D
4.69E-02
7.42E-02
5.20 E-02
8.96E-06
3.82E-02
- -
- -
R
7.16E-09
1.15E-OS
8.00E-09
1.39E-12
6.01E-09
TOTAL 2.11E-01 3.27E-08
A-92
-------
AVERAGE CPO MOESTION OF
9 CONTAMINATED BY DUST DEPOSITION
ten Urmnlum Overburden
& 2.66E+02
S- 6.90E-07
D(mretn) . Q S C OHng Uf
R(fatal eanewv) - Q S * C RFIng * Uf
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1.66E+01
1.66E+01
2.37E+01
1.00E+00
1 .OOE+00
2.37E+01
1.00E+00
2.37E*01
2.37E4-01
1.20E>00
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RRng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
Uf
1.31E-02
1.31E-02
1.31E-02
1 .29E-02
1.29E-02
1.31E-02
1 .29E-02
2.21 E-02
2.21 E-02
2.21 E-02
D
7.58E-08
2.16E-07
7.41 E-08
9.47E-10
3.31 E-09
3.13E-08
6.39E-09
2.69E-08
2.40E-08
1.31 E-09
R
1.16E-14
3.35E-14
1.14E-14
1.47E-16
5.21 E-16
4.84E-15
9.94E-16
4.13E-15
3.75E-15
2.04E-16
TOTAL 4.60E-07 7.11E-14
A-93
-------
I9b
AVERAGE CM MOESTON OF
FOODSTUFFS CONTAUMATEO BY OUST DEPOSITION
Ion Phoffhm* Wm»t»
& 2.66E+02
S- 2.83E-07
D(mrwn) - Q S * C DRng * Uf
R(fatal cancan) - Q S C RRng * Uf
Nuelld*
1*0-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
HFIiiB
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
Uf
1.31E-02
1.31E-02
1.31E-02
1.29E-02
1.29E-02
1.31E-02
1.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
D
4.95E-08
1.41E-07
4.23E-08
1.05E-10
3.67E-10
7.05E-09
7.08E-10
2.89E-09
2.50E-09
1.35E-10
R
2.19E-14
6.51 E-1 5
1.63E-17
S.77E-17
1.09E-15
1.10E-16
4.44E-16
3.89E-16
2.10E-17
TOTAL 2.46E-07 3.81 E-14
A-94
-------
I9e
AVERAGE CPO - MCESTION OF
FOODSTUFFS CONTAMINATED BY DUST DEPOSITION
Q. 2.66E+02
S- 6.90E-07
D(mrem) - G * S C DRng * Uf
R(fatal cancers) - Q * S
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1 .80E-03
1 .80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1.70E-02
1 .70E-02
8.60E-04
DFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
C RFing
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
Uf
Uf
1.31 E-02
1.31 E-02
1.31 E-02
1.29E-02
1 .29E-02
1.31 E-02
1.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
D
8.22E-12
2.34E-1 1
7.81 E-1 2
3.22E-13
1.13E-12
2.12E-11
1.98E-12
1.93E-11
1.72E-11
9.42E-13
R
1.26E-18
3.64E-18
1.20E-18
4.99E-20
1.77E-19
3.27E-18
3.08E-19
2.97E-18
2.69E-18
1.47E-19
TOTAL 1.01 E-10 1.57E-17
A-95
-------
I9d
AVERAGE CPO MOEST1ON OF
ICOHTAMMATED BY DUST DEPOSITION
far: CM* Art
G. 2.66E+02
S- 1.32E-07
D(mrom) . Q S C * DRng Uf
R(fatal cancan) - G S * C RHng * Uf
Nuelldi
DFIna
RFIng
Uf
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
7.00E+00
8.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1 .40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
1.31E-02
1.31E-02
1.31E-02
1.29E-02
1.29E-02
1.31E-02
1 .29E-02
2.21 E-02
2.21 E-02
2.21 E-02
6.12E-09
1.69E-08
2.21 E-09
S.80E-10
1.14E-09
5.82E-10
2.S7E-09
7.17E-10
6.40E-10
3.3SE-11
9.34E-16
2.63E-15
3.40E-16
8.99E-1 7
1.79E-16
8.99E-17
3.99E-16
1.10E-16
9.99E-17
5.21 E-1 8
TOTAL 3.15E-08 4.88E-15
A-Q6
-------
19*
AVERAGE CPQ - WGESTKJN OF
FOODSTUFFS CONTAMINATED BY DUST DEPOSITION
Mfeter Tnmt Sludg* (Ftrtlllzir)
Q. 2.66E+02
8. 8.28E-07
Nuelld*
Pe-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
D(mrem) . Q S C * DFing * Uf
R(fatal cancara) - Q * S C RFIng * Ul
C DFInfl RFIng Uf
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1 .20E-03
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10 1
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11 i
3.90E-11 i
4.20E-11 '
.31 E-02
.31E-02
.31 E-02
.29E-02
.29E-02
.31 E-02
.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
D
2.19E-09
6.23E-09
2.40E-09
9.09E-12
3.18E-09
1.27E-11
6.14E-11
2.18E-10
1.9SE-10
1.58E-12
R
3.3SE-16
9.69E-16
3.69E-16
1.41E-18
5.00E-16
1.96E-18
9.55E-18
3.35E-17
3.04E-17
2.45E-19
TOTAL 1.45E-08 2.25E-15
A-97
-------
I9f
AVERAGE CPG MOESTION
FOODSTUFFS COKTAIUNATED BY DUST
ton Wmttf Tnmt Sludg* (Ltndail)
Q. 2.66E+02
S- 8.95E-07
D(mrem) - Q * S * C * DRng Uf
R(fatal cancer*) - Q S C * RHng * Uf
JF
DEPOSITION
Nuclld*
DFIng
RRng
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
1 .90E-03
S.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11 !
3.90E-11 !
4.20E-11 i
.3- i-02
.3- =-02
.3 =-02
.2! =-02
.2! =-02
.3 =-02
.2!- =-02
2.2 =-02
2.2 i-02
2.2 =-02
8.89E-10
2.53E-09
9.73E-10
3.69E-12
1.29E-09
5.15E-12
2.49E-1 1
8.84E-11
7.89E-11
7.10E-13
1.36E-16
3.93E-16
1.50E-16
S.71E-19
2.03E-16
7.9SE-19
3.87E-18
1.36E-17
1.23E-17
1.10E-19
TC 'AL 5.88E-09 9.12E-16
A-98
-------
I9g
AVERAQE CPO - INOESnON OF
FOODSTUFFS CONTAMINATED BY DUST DEPOSITION
ton Un»nl Procuring Wmsto
G- 2.66E+02
S- 6.85E-07
D(mrem) - Q S * C * DRng * Uf
R(tatal cancan) . G S * C RRng * Uf
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E+01
1 .OOE+01
3.50E+01
3.50E+01
1.80E+00
DFlna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
HFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11 I
3.90E-11 !
4.20E-11 '
Uf
.31 E-02
.31E-02
.31 E-02
.29E-02
.29E-02
.31 E-02
.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
D
1.13^-07
3.22E-07
1 .09E-07
9.40E-09
3.29E-08
4.59E-08
6.35E-08
3.9SE-08
3.52E-08
1.96E-09
R
1.73E-14
5.01 E-1 4
1.67E-14
1.46E-15
5.17E-1S
7.10E-15
9.87E-15
6.06E-15
S.50E-15
3.04E-16
TOTAL 7.73E-07 1.20E-13
A-99
-------
I9h AVERAGE CPO - MGESTtON OF
FOODSTUFFS CONTAMINATED BY DUST DEPOSITION
tor. Oil * OM SeaH/ Sludg*
G. 2.66E+02
S- 6.39E-08
D(mrem) . Q * S C DRng * Uf
R(fatal cancers) - Q * S * C RRng * Uf
Nuclld* C DFIng RFIna Uf
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1 .55E+02
1.55E+02
1.55E+02
5.50E+01
5.50E+01
. .
- -
. .
»
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
- -
- -
- -
- -
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
- -
- -
- -
.31 E-02
.31 E-02
.31 E-02
.29E-02
.29E-02
- -
- -
6.56E-08
1 .86E-07
4.49E-08
4.82E-09
1 .69E-08
- -
-
- -
- -
1.00E-14
2.90E-14
6.90E-15
7.48E-16
2.65E-15
- -
- -
- -
- -
TOTAL 3.19E-07 4.93E-14
A-100
-------
191
AVERAGE CPQ MGESTION OF
FOODSTUFFS CONTAUMATED BY DUST DEPOSITION
fen OcotlMniwI Wm»l»
Q. 2.66E+02
S.6.01E-08
O(mram) - Q * S * C DRng Uf
R((atal cancan) - Q * S * C * RPIng Uf
Nuelld*
'0-211
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1.10E+02
1.10E+02
1.60E+02
3.00E+01
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
Uf
1.31E-02
1.31E-02
1.31E-02
1 .29E-02
D
4.38E-08
1.24E-07
4.36E-08
2.47E-09
R
6.68E-15
1.94E-14
6.70E-15
3.84E-16
1.10E+02 1.40E-03 2.20E-10 1.29E-02 3.18E-08 4.99E-15
TOTAL 2.46E-07 3.81 E-14
A-101
-------
I10e
INGESTON OF FOODSTUFFS GROWN ON
REPEATEDLY FERTILIZED SOIL
OTHER INDIVIDUAL
ton
G- 1.00E+03
S-1.00E+00
D(mrem) - Q S C * DFlng * Uf
R(fatal cancan) . Q S C * RRng * Uf
Nuelld*
DFIna
RFIna
Uf
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
1.80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1.70E-02
1 .70E-02
8.60E-04
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
1.31E-02
1.31E-02
1.31E-02
1.29E-02
1.29E-02
1.31E-02
1.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
4.48E-05
1 .27E-04
4.26E-05
1 .75E-06
6.14E-06
1.15E-04
1 .08E-OS
1 .05E-04
9.39E-05
5.13E-06
6.84E-1 2
1.98E-11
6.55E-12
2.72E-13
9.65E-13
1.78E-11
1.68E-12
1.62E-11
1.47E-11
7.98E-13
TOTAL 5.53E-04 8.55E-11
A-102
-------
no*
OTHER INDIVIDUAL - INGESTION OF FOODSTUFFS GROWN ON
REPEATEDLY FERTILIZED SOIL
Mtefw Tnut Sludg» (FtrtHlxir)
Q. 1.00E+03
S-1.00E+00
D(mrem) - Q * S C DRng Uf
R(fatai cancers) - G * S C RFing * Uf
Nucllda
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1 .60E-01
1 .20E-03
OFIng
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFlng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-1 1
4.20E-11
Uf
I.31E-02
I.31E-02
.31E-02
.29E-02
.29E-02
.31E-02
.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
D
9.96E-03
2.83E-02
1.09E-02
4.13E-05
1.44E-02
5.76E-05
2.79E-04
9.90E-04
8.84E-04
7.16E-06
R
1.52E-09
4.40E-09
1.68E-09
6.40E-12
2.27E-09
8.91 E-1 2
4.33E-11
1.52E-10
1.38E-10
1.11E-12
TOTAL 6.59E-02 1.02E-08
A-103
-------
POP. - OOWNWMD EXPOSURE TO RESUSPENOEO PARTICULATES
tor. Unnlum Ovwfturrfwi
G- 1.00E+03
G1- 8.00E+03
Q2- 3.15E+05
G3- 4.50E+02
S- 1.77E-06
PR(fatal cancers) - G S * C l(G1*RFInh) * (G2*RFG) + (GS'UI'RFJng)]
PtXpereon mrem) - G * S * C l(Gl'DFInh) * (G2*OFG) « (G3*Uf*DFlng)]
C DFIng RFInfl DFInh RFInh PD
PR
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
1.31E-02
1.31E-02
1.31E-02
1.29E-02
1.29E-02
1.31E-02
1.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
1 .66E>01
1.66E*01
2.37E*01
1 .OOE+00
1 .OOE+00
2.37E+01
1.00E+00
2.37E+01
2.37E+01
1.20E*00
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
9.40E-03
1 .40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
S.10E-08
2.50E-07
2.00E-08
1 .90E-08
1.90E-08
2.21 E+00
3.29E+00
5.09E*00
S.OOE^OO
1.18E-01
1.11E4-02
2.27E+01
4.36E4-01
4.03E*01
2.05E+00
3.53E-07
5.18E-07
1.30E-06
8.23E-07
3.00E-08
1.71E-05
3.54E-06
6.71 E-06
6.38E-06
3.27E-07
TOTAL
2.35E+02 3.71 E-OS
A-104
-------
P1 b
POP. DOWNWMD
tar Pho»phmt» W»»t»
G. 1.00E+03
01. 8.00E+03
02- 3.15E+05
03- 4.50E+02
S-4.51E-06
TO RESUSPENOEO PARTWULATES
PR(fata) cancers) . G * S
PCXperson mrem) G * S
Nuelld* Uf C
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234 !
U-238 i
U-235 !
.31 E-02
.31 E-02
.31 E-02
.29E-02
.20E-02
.31 E-02
.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
C ' ((Gl'RFInh) + (G2*RFG) + (G3*UrRFIng)J
C * ((GVOFInh) + (G2*DFG) i- (G3*Uf*DFIng)]
ORnfl RRna ORnh RFInh
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-1 1
3.90E-11
4.20E-11
9.40E-03
1 .40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E>00
1.30E-01
1 .20E-01
1.20E-01
1.SOE-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
S.10E-08
2.50E-07
2.00E-08
1.90E-08
1.90E-08
PO
8.95E+00
1.33E+01
1.81E+01
3.44E+00
8.14E-02
1.55E+02
1.56E+01
2.91 E+01
2.60E+01
1.31E+00
PR
1.43E-06
2.10E-06
4.60E-06
5.66E-07
2.06E-08
2.39E-05
2.44E-06
4.47E-06
4.11E-06
2.08E-07
TOTAL 2.71 E*02 4.39E-05
A-105
-------
P1e
POP.- DOWNWMD EXPOSURE TO RESUSPENDED PART1CULATES
Phoiphmto ftrttttnr
G- 1.00E+03
G1- 8.00E+03
G2.3.15E+05
G3- 4.50E+02
& 5.82E-06
PR(fataJ cancers) - G S C [(QTRRnh) + (G2*RFG) + (G3*UfRRng)]
PtXperaon mrem) . G S C [(Gl'DFInh) * (G2'DFG) + (63'UfDFing)]
Nuclld* Uf C DFIna RFIna DFInh RFInh
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
.31 E-02
.31 E-02
.31 E-02
.29E-02
.29E-02
.31 E-02
.29E-02
U-234 2.21 E-02
U-238 2.21 E-02
U-235 2.21 E-02
1.80E-03
1.80E-03
2.SOE-03
3.40E-04
3.40E-04
1.60E-02
3.10E-04
1 .70E-02
1.70E-02
8.60E-04
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-1 1
4.20E-10
4.30E-11
3.90E-11
4.20E-11
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
1.50E-09
2.20E-09
1 .30E-09
S.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1.90E-08
PD
7.88E-04
1.17E-03
1.77E-03
5.59E-03
1.32E-04
2.46E-01
2.31 E-02
1.03E-01
9.50E-02
4.83E-03
PR
1.8SE-10
4.49E-10
9.20E-10
3.35E-11
3.80E-08
3.61 E-09
1.58E-08
1.50E-08
7.71 E-10
TOTAL 4.81 E-01 7.50E-08
A-106
-------
Pld POP. -DOWHWMO EXPOSURE TO RESUSPENDED PARTICULATES
tan Co* Ath
G- 1.00E+03
Q1- 8.00E+03
G2-3.15E+05
G3- 4.SOE+02
& 0.83E-07
PR(fatal cancers) - G * S C ((OVRRnh) + (G2*RFG) + (G3'UfRFIng)l
PCKparson rnrem) - Q * S C ((01'DFlnh) + (G2*DFG) * (G3*UfDRng)]
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234 i
U-238 !
U-235 !
.31^-02
.31E-02
.31 E-02
.29E-02
.29E-02
.31 E-02
.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
r
C
7.00E+00
6.80E+00
3.70E*00
3.20E>00
1 .80E>00
2.30E+00
2.10E+00
3.30E>00
3.30E+00
1.60E-01
DFIna
1.90E-03
S.40E-03
1.30E-03
4.00E-O4
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-1 1
4.20E-10
4.30E-11
3.90E-11
4.20E-11
DFlnh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
RFInh
1.SOE-09
2.20E-09
1.30E-09
S.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1.90E-08
1.90E-08
PD
5.18E-01
7.49E-01
4.42E-01
8.89E+00
1.18E-01
5.97E>00
2.64E>01
3.37E+00
3.11E+00
1.52E-01
PR
8.26E-08
1.18E-07
1.12E-07
1.46E-06
3.00E-08
9.22E-07
4.13E-06
5.19E-07
4.93E-07
2.42E-08
TOTAL 4.97E+01 7.89E-06
A-107
-------
P1« POP. OOWNWMD EXPOSURE TO RESUSPENDED P/ MKULATES
tor; Wtttr Tnmt Sludg» (F*rtllU»r)
G- 1.00E+03
G1- 8.00E+03
G2-3.15E+05
G3- 4.50E+02
S» 6.14E-06
PR(lata) cancers) - G S * C [(GVRFInh) * (G2*RFG) + (GS'UfRi ng)]
PD(pereon mrem) - G * S C [(Gl'DFinh) * (G2'DFG) * (GS'UfOF 1fl)l
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
Uf
1.31 E-02
1 .31 E-02
1.31 E-02
1 .29E-02
1 .29E-02
1.31 E-02
1 .29E-02
2.21 E-02
2.21 E-02
2.21 E-02
C
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1 .60E-01
1.60E-01
1.20E-03
DFIng
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFInfl
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1 .20E-01
1.20E-01
Rl nh
1.5( i-09
2.2( =-09
1.3( H-09
S.3( =-08
7.4( MO
5.1 ( =-08
2.5( =-07
2.0( =-08
1.9c =-08
1.9( =-08
PD
1.85E-01
2.75E-01
4.77E-01
1.39E-01
3.29E-01
1.30E-01
6.29E-01
1.02E+00
9.43E-01
7.11E-03
PR
2.95E-08
4.33E-08
1.21E-07
2.28E-08
8.32E-08
2.00E-08
9.82E-08
1 .57E-07
1.49E-07
1.14E-09
TC ~AL 4.13E+00 7.26E-07
A-108
-------
Pit
POP. - DOWNWMO EXPOSURE TO RESUSPENOED PARTICULATES
ton Wmttr Tnmt Sludg» (Lmndflll)
G- 1.00E+03
Q1- 8.00E+03
G2- 3.15E+05
G3- 4.50E+02
S- 1.25E-06
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
PR(»atal cancers) - G * S
PD(person mrem) - G * S
Uf C
i
i
.31 £-02
.31 E-02
.31 E-02
.29E-02
.29E-02
.31 E-02
.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
1 .50E-01
1 .50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
C * [(GrRFinh) + (G2'RFG) + (G3*Uf*RFing)J
C * [(GI'DRnh) + (G2'DFG) + (GS'UfDRng))
DFInfl RFIng DFInh RFInh
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
S.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-1 1
4.20E-11
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1 .30E-01
1.20E-01
1.20E-01
1.50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1 .90E-08
PD
1.41 E-02
2.10E-02
3.64E-02
1.06E-02
2.51 E-02
9.90E-03
4.80E-02
7.80E-02
7.20E-02
6.03E-04
PR
2.25E-09
3.31 E-09
9.26E-09
1.74E-09
6.35E-09
1.53E-09
7.50E-09
1.20E-08
1.14E-08
9.63E-1 1
TOTAL 3.16E-01 5.54E-08
A-109
-------
P1g POP. - OOWNWMO EXPOSURE TO RESUSPENOEO PARTICULARS
far: Untnl Processing Wm»t»
G- 1.00E+03
Q1. 8.00E+03
02- 3.15E+05
Q3- 4.50E+02
S. 5.23E-07
PR(fataJ cancers) - Q * S C KGVRFinh) + (G2'RFG) * (GS'UfRFing)]
PtXperson mrem) - G * S * C KGI'DFInh) + (G2'DFG) *
Nuelldc
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
Uf
1.31E-02
1.31E-02
1.31E-02
1 .29E-02
1 .29E-02
1.31E-02
1 .29E-02
2.21 E-02
2.21 E-02
2.21 E-02
C
2.50E+01
2.50E+01
3.50E*01
1.00E+01
1 .OOE+01
3.50Ef01
1 .OOE*01
3.50E*01
3.50E+01
1.80E*00
DFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
HFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
3.30E-01
1.60E+00
1.30E-01
1.20E-01
1.20E-01
RFInh
1.50E-09
2.20E-09
1.30E-09
S.30E-08
7.40E-10
5.10E-08
2.50E-07
2.00E-08
1 .90E-08
1 .90E-08
PD
9.83E-01
1.47E+00
2.22E+00
1.48E*01
3.SOE-01
4.83E+01
6.69E>01
1.90E+01
1.76E*01
9.09E-01
PR
1.57E-07
2.31 E-07
5.65E-07
2.43E-06
8.86E-08
7.47E-06
1.0SE-05
2.93E-06
2.78E-06
1 .45E-07
TOTAL
1.73E+02 2.73E-05
A-110
-------
P1h
PR(fata) cancers) -
PD(parson mrem)
POP. - DOWNWWD EXPOSURE TO RESUSPENOEO PAR1WULATES
far; OU * OM ScmW STudg*
G. 1.00E+03
G1- 8.00E+03
G2-3.15E+05
G3- 4.60E+02
S- 2.72E-08
G * S C [(GI'RRnh) + (G2*RFG)
G S * C ' [(QrDRnh) * (G2*DFG)
+ (G3*UfRRng)]
(G3*UfDRng)]
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
Uf
1.31 E-02
1.31 E-02
1 .31 E-02
1.29E-02
1 .29E-02
1.31 E-02
1 .29E-02
2.21 E-02
2.21 E-02
2.21 E-02
C
1.55E+02
1 .55E+02
1.55E+02
5.50E*01
5.50E+01
- .
. .
. .
. .
DFInfl
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
- -
- -
- -
- -
HRna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
- -
- -
- -
- -
DFInh
9.40E-03
1 .40E-02
8.60E-03
3.40E-01
4.80E-03
RFInh
1 .50E-09
2.20E-09
1.30E-09
5.30E-08
7.40E-10
- -
- -
- -
PO
3.17E-01
4.73E-01
5.12E-01
4.23E+00
1.00E-01
- -
-
-
- -
PR
S.06E-08
7.44E-08
1.30E-07
6.96E-07
2.54E-08
- -
*
TOTAL 5.63E+00 9.76E-07
A-111
-------
P11 POP. DOWNWMD EXPOSURE TO RESUSPENDED PART1CULATES
ton OMtfMmMl Wmtt»
G- 1.00E+03
01- 8.00E+03
G2- 3.15E+05
G3» 4.50E+02
S- 5.05E-O8
PR(fataJ cancers) - Q * S C * [(GI'RRnh) + (G2'RFG) + (G3*UfRRng)l
PDiperson mrem) - G S C [(Q1*DFWi) * (G2'DFG) * (G3*Uf'DRng)|
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
1.31 E-02
1 .31 E-02
1.31 E-02
1 .29E-02
1.29E-02
1.31 E-02
1.29E-02
2.21 E-02
2.21 E-02
2.21 E-02
1.10E+02
1.10E+02
1 .60E+02
3.00E+01
1.10E+02
. -
. .
»*
1.90E-03
S.40E-03
1.30E-03
4.00E-04
1.40E-03
-
- -
- -
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
- -
-
-
DFInh
9.40E-03
1.40E-02
8.60E-03
3.40E-01
4.80E-03
-
- -
- -
RFInh
1.50E-09
2.20E-09
1 .30E-09
5.30E-08
7.40E-10
- -
- -
- -
- -
PD
4.18E-01
6.23E-01
9.81 E-01
4.28E+00
3.72E-01
*
"
"
" "
PR
9.80E-08
2.49E-07
7.04E-07
9.41 E-08
"
"
"
"
"
TOTAL 6.67E+00 1.21E-06
A-112
-------
P2« POPULATION. DOWNWMO EXPOSURE TO rfADON
ten Urmlum Orarfeurdten
-------
P2b POPULATION -DOWNWIND EXPOSURE TO RADON
ton Photphatf IMute
Q. 2.53E+00
S- 1.28E+04
OR- 4.90E-07
PR(fatal cancers) - Q * S DFr
Nuclld* PR
Ra-226 1 .S9E-02
TOTAL 1.50E-02
A-114
-------
P2e POPULATION-DOWNWMO EXPOSURE TO RADON
Ion Phoiphmt* Ftrtflliw
O. 2.53E+00
S-1.28E-01
OR- 4.90E-07
PR(fatal cancan) - Q S DFr
Nuclld* PR
Ra-226 1.59E-07
TOTAL 1.50E-07
A-115
-------
P2d POPULATION DOWNWMO EXPOSURE TO RADON
Q- 2.53E+00
S- 6.31 E+01
OR- 4.90E-07
PR(fatal cancan) - Q S * DFr
Nuelld* _ PR
Ra-226 7.82E-05
TOTAL 7.82E-05
A-116
-------
P2« POPULATION - DOWNWMD EXPOSURE TO RAOON
ton Mtofw tt»«l S/urf0«
G. 2.53E+00
S- 3.76E+01
DFr- 4.90E-07
PR(fatal cancan) - Q S OFr
Nuclld* PR
Ra-226 4.66E-05
TOTAL 4.66E-05
A-117
-------
pgf POPULATIOM - DOWMWBJD EXPOSURE TO RADON
ten Motor Troat Sludgo (Landfill)
GD 2.53E+00
&> 9.91 E+00
4.90E-07
PR(fatal eaneere) «» Q S DFr
Nuelldo PR
Ra-226 1.23E-OS
TOTAL 1.23E-05
A-118
-------
P2g POPULATION -DOWNWIND EXPOSURE TO feADON
tar; MTiMral Pmcinlng Witt*
G- 2.53E+00
S- 1.35E+03
Oft- 4.90E-07
PR(fatal cancan) - G S DFr
Nuelld* PR
Ra-226 1.67E-03
TOTAL 1.67E-03
A-119
-------
P2h POPULATION DOWNWIND EXPOSURE TO RADON
Ion Oil « OM SciM/ Sfurf0«
& 2.53E+00
S- 5.48E+02
DFr- 4.90E-07
PR(fata) cancers) - G * S DFr
Nuclld* PR
Ra-226 6.79E-04
TOTAL 6.79E-04
A-120
-------
P2I POPULATION DOWNWIND EXPOSURE TO RADON
ten Ofcthtnuml Wm*t»
Q. 2.53E+00
S- 4.45E+03
OR- 4.90E-07
PR(fatal cancan) - G S * DFr
Nuclld* PR
Ra-226 5.52E-03
TOTAL 5.52E-03
A-121
-------
POPULATION INOESTION OF RIVER WATER
OONTAUNATED VU THE OROUNOWATER PATHWAY
lor: Unnlum Ovwfeurdwi
Q. 2.00E-07
S- 3.27E+15
1-«xp-3.40E-05
PDfmrem) - (G S C * UW DFIng (1-exp)) / R
PRffatal cancan) - (O * S * C Uw * RFlng * (1-exp)) /
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1 .66E+01
1.66E+01
2.37E+01
1.00E+00
1.00E+00
2.37E+01
1.00E+00
2.37E>01
2.37E+01
1.20E*00
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.SOE-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFInn
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E*02
8.18E+04
8.18E+04
2.46E+02
2.46E4.02
2.46E>02
Uw
9.43 E-01
9.43E-01
9.43 E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
2.41 E+00
3.82E+00
2.63E*00
1.02E-04
1.19E-01
3.34E-03
6.89E-04
5.25E-01
4.69E-01
2.57E-02
PR
.68E-07
5.94E-07
4.04E-07
1.S8E-11
1.87E-08
5.16E-10
1.07E-10
8.07E-08
7.32E-08
3.99E-09
TOTAL
1.00E+01 1.54E-06
A-122
-------
P3b
POPULATION INGESmON OF RIVER WATER
CONTAMNATED VIA THE QROUNDWATER PATHWAY
tor. Phtupha* Witt*
G. 2.00E-07
S- 6.71E+15
1-exp. 3.50E-02
PD(mrem) - (Q S * C * UW DRng (1-exp)) / R
PR(fatal cancan) (Q S C * Uw * RRng (1-exp)) / R
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
DFIng
1.90E-03
S.40E-03
1 .30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73^+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E>05
2.45E+03
2.45E>03
2.45E+03
Uw
9.43E-01
9.43 E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PO
.14E+02
1.29E+03
7.76E+02
5.82E-03
6.80E+00
3.87E-01
3.93E-02
2.92E+01
2.52Ef01
1.36E+00
PR
1 .24E-04
2.00E-04
1.19E-04
9.03E-10
1.07E-06
5.98E-08
6.11E-09
4.48E-06
3.93E-06
2.12E-07
TOTAL 2.94E+03 4.53E-04
A-123
-------
P3c
POPULATION - DIGESTION OF RIVER WATER
CONTAMNATED VIA THE GROUNDWATER PATHWAY
Phe»plimt» FmrtllUw
G. 2.00E-07
S- 6.52E+13
1-axp. 8.80E-03
' Uw * ORng * (1-exp)) / R
S * C * Uw * RFIng * (1-exp)) / R
PD(mram) (Q * S * C
PR(fatal cancers) (Q
Nuclld*
f»o-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1 .80E-03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1.70E-02
1.70E-02
8.60E-04
OFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.SOE-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.45E+03
2.45E+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
1.36E-04
2.14E-04
1.44E-04
1.79E-08
2.09E-05
1.16E-06
1.10E-07
1.95E-04
1.74E-04
9.53E-06
PR
.07E-11
3.33E-11
2.21 E-11
2.78E-15
3.29E-12
1.80E-13
1.72E-14
3.00E-11
2.72E-11
1.48E-12
TOTAL 8.95E-04 1.38E-10
A-124
-------
PM
POPULATION - INGEST1ON OF ftlVER WATER
CONTAIBNATEO VIA THE GROUNDWATER PATHWAY
ferrCMf Afh
Q. 2.00E-07
S- 2.55E+15
1-«xp-6.70E-02
PCKmrem) - (Q S * C * UW ORng * (1-exp)) / R
PR(fatal cancers) - (Q S * C * UW RFIng * (l*xp)) / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E4-00
1.60E-01
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.SOE-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
5.46E+02
5.46E+02
4.10E+02
1.64E+04
4.10E+02
1.64E+04
1.64E+04
2.74E+02
2.74E+02
2.74E+02
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
7.85E+02
2.17E+03
3.78E+02
2.50E+00
1.97E+02
2.49E+00
1.11E+01
1.01E+02
9.01 E+01
4.72E+00
PR
1 .20E-04
3.37E-04
5.82E-05
3.88E-07
3.10E-05
3.84E-07
1.73E-06
1.55E-05
1.41E-05
7.34E-07
TOTAL 3.74E+03 5.79E-04
A-125
-------
P3«
POPULATION INGESTION OF RIVER WATER
OONTAIONATED VIA THE GROUNDWATER PATHWAY
tor. Wmtur Tnml Sludg» (F»rtUU*r)
Q. 2.00E-07
S- 6.52E+13
1-«xp-8.70E-03
P0(mrwn) - (Q S * C * Uw ' DFIng (1-axp)) / R
PRXfatal cannra) - (Q S C Uw RHng * (1-«p)) / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
4.00E-01
4.00E-01
6.40E-01
8.00E-03
8.00E-01
8.00E-03
8.00E-03
1.60E-01
1.60E-01
1.20E-03
DPIna
1.90E43
5.40E-03
1.30E-03
4.00E-04
1.40E-03
S.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E>03
8.18E^05
8.18E-fOS
2.45E+03
2.45E+03
2.45E+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
2.98E-02
4.71 E-02
3.63E-02
4.17E-07
4.87E-02
5.75E-07
2.81 E-06
1.82E-03
1.62E-03
1.31E-05
PR
4.55E-09
7.32E-09
5.59E-09
6.46E-14
7.65E-09
8.89E-14
4.38E-13
2.79E-10
2.53E-10
2.04E-12
TOTAL
1.6SE-01 2.56E-08
A-126
-------
P3f
POPULATION INGESTION OP RIVER WATER
CONTAIONATED VIA THE GROUNDWATER PATHWAY
tor. Wmtur Tnml Sludg* (Lmndail)
& 2.00E-07
S- 2.93E+14
1-exp- 2.20E-04
P0(mram) - (Q * S C Uw DRng * (1-exp)) / R
PR(fatal cancan) - (O S C * UW RFIng (1-exp)) / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
DRng
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RRnfl
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.4SE+03
8.18E>05
2.4SE>03
8.18E+05
8.18E>05
2.4SE+03
2.45E*03
2.45E+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PO
1.27E-03
2.01E-03
1.55E-03
1.78E-08
2.08E-03
2.45E-08
1.20E-07
7.74E-05
6.91 E-05
6.22E-07
PR
1.94E-10
3.12E-10
2.38E-10
2.75E-15
3.26E-10
3.79E-15
1.86E-14
1.19E-11
1.08E-11
9.68E-14
TOTAL 7.0SE-03 1.09E-09
A-127
-------
P3g
POPULATION INGESTON OF AlVER WATER
CONTAUMATED VIA THE GROUNDWATER PATHWAY
ten MbMraf Procuring W**t»
Q. 2.00E-07
3- 2.14E+1S
1-exp-2.00E-06
PDdnrem) - (Q * S C * UW DFIng (1-axp)) / R
PR(fatal cancers) . (O S C * UW RRng * (1-«xp» / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1 .OOE+01
1 .OOE+01
3.50E+01
1 .OOE+01
3.50Ef01
3.50E>01
1 .80E+00
DFInfl
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-1 1
3.90E-11
4.20E-11
R
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E*02
8.18E+04
8.18E+04
2.46Ei4)2
2.46E+03
2.46E+02
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
2.21 E-01
1.49E-01
3.93E-OS
4.57E-02
1 .90E-04
2.65E-04
2.99E-02
2.67E-03
1 .48E-03
PR
.14E-08
3.45E-08
2.30E-08
6.09E-12
7.19E-09
2.94E-1 1
4.13E-11
4.59E-09
4.16E-10
2.30E-10
TOTAL 5.91 E-01 9.13E-08
A-128
-------
P3h POPULATION - INOESTION Of RIVER WATER
COKTAMMATEO VIA THE GROUNOWATER PATHWAY
ton OU « OM SemW Studg»
G. 2.00E-07
S- 2.28E+14
1-exp-3.00E-03
P0(mrem) . (Q S C Uw DFlng (1-«xp)) / R
PR(fatal cancers) - (Q * S * C * Uw RHng * (1-exp)) / R
Nuclld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1.55E+02
1.S5E+02
1.55E+02
5.50E+01
5.50E+01
. -
Dflng
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
- -
- -
- -
- -
- -
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
- -
R
5.46E+02
5.46E+02
1.36E+04
1.36E+04
1.36E+04
Uw
9.43 E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
- -
- -
-
- -
PO
6.96E+01
1.98E+02
1.91E>00
2.08E-01
7.27E-01
-
- -
-
-
PR
1.06E-05
3.08E-05
2.94E-07
3.22E-08
1.14E-07
TOTAL 2.70E+02 4.18E-05
A-129
-------
P3I
PD(i ram)
PR(f tal
POPULATION INGESTION OF RIVER WATER
CONTAMINATED VIA THE GROUNDWATER PATHWAY
for: OMlftcniM/ Wut»
G. 2.00E-07
S- 4.62E+14
-axp- 5.80E-05
Uw DFIng * (1-«xp)) / R
S * C * Uw * RRng (1-exp)) /
(Q
S * C
(Q
Uw
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
Nuclld* C DFinfl RFlnq R
TT ST55 1.90E-03 2.90^-10 2.74^*02 9.43E-01
1.1 E+02 5.40E-03 8.40E-10 4.92E+02 9.43E-01
1.6 E+02 1.30E-03 2.00E-10 2.46E+02 9.43E-01
3.C E+01 4.00E-04 6.20E-11 8.18E*04 9.39E-01
1.1 E>02 1.40E-03 2.20E-10 2.46E+02 9.39E-01
PO
3.85E+00
PR
S.88E-07
6.10E*00 9.49E-07
4.27E+00 6.S7E-07
7.38E-04 1.14E-10
3.1SE+00 4.95E-07
TOTAL 1.74E+01 2.69E-06
A-130
-------
POPULATION INGESTION OF RIVER
WATER CONTAMINATED BY SURFACE RUNOFF
r: Omnium
Q. 3.50E-09
S» 7.06E+16
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-236
PDOnram) -
PR(fatalcan
c
1.66E+01
1.66E+01
2.37E+01
1.00E+00
1.00E>00
2J7E*01
1.00E*00
2.37E+01
2JJ7E+01
1.20E*00
(Q S C *
eon) » (Q *
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
Uw DRng )
S * C * Uw '
RRng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
/R
RRng ) / R
R
2.74E+02
4.92E+02
2.46E*02
8.18E+04
2.46E+02
8.18E>04
8.18E+04
2.46E+02
2.46E*02
2.46E+02
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PO
2.68E+04
4.25E+04
2.92E+04
1.13E>00
1.32E+03
3.71 E+01
7.66E+00
5.84E4-03
5.21 E+03
2.85E+02
PR
4.09E-03
6.60E-03
4.49E-03
1.76E-07
2.08E-04
5.74E-06
1.19E-06
8.97E-04
8.13E-04
4.43E-05
TOTAL 1.11E+05 1.72E-02
A-131
-------
P4b
POPULATION - INGESTION OF RIVER
WATER CONTAMINATED BY SURFACE RUNOFF
tor. Pho*ph»t»
fr 3.50E-O9
& 1.03E+18
P0(mrem)
PR(fatal
(Q S * C
» - (G '
Uw * DPIng ) / R
S * C * Uw * RFlng ) / R
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-23S
C
2.64E+01
2.64E+01
3.30E+01
2.70E-01
2.70E-01
1.30E+01
2.70E-01
6.20E+00
6.00E+00
3.00E-01
DFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E*OS
2.45E*03
8.18E+05
8.18E*05
2.45E+03
2.45E+03
2.45E+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PO
6.25E+04
9.87E+04
5.95E*04
4.47E-01
5.22E+02
2.97E+01
3.02E+00
2.24E+03
1.93E+03
1.04E+02
PR
1.54E-02
9.16E-03
6.93 E-08
8.21 E-05
4.59E-06
4.69E-07
3.44E-04
3.02E-04
1.62E-OS
TOTAL 2.26E+05 3.48E-02
A-132
-------
P4e
VMVKVt WWW BMHHnM I KM 0V 9Wir^n«^ ni»fww
Photphttf FurtlUxfr
(^ 3.50E-09
S- 2J2E+17
PD(mrem) - (Q S C Uw DRng ) / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
PR(fatal cam
C
1.80E--03
1.80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1.70E-02
1 .70E-02
8.60E-04
yon) » (Q S C * Uw *
OFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
S.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-1 1
4.20E-11
RFIng ) / R
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.45E+03
2.45E+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
9.59E-01
1.52E+00
1.02E+00
1.27E-04
1.48E-01
8.24E-03
7.80E-04
1.38E+00
1.23E+00
6.74E-02
PR
1 .46E-07
2.36E-07
1 .56E-07
1 .96E-1 1
2.33E-08
1.27E-09
1.21E-10
2.12E-07
1 .92E-07
1.05E-08
TOTAL 6.33E+00 9.78E-07
A-133
-------
P44
POPULATION INOESnON OF RIVER
WATER CONTAMINATED BY SURFACE RUNOFF
Nuclld*
Po-210
Pb-210
Ra-228
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
G.
S-
PD(mrem)
PR(tata) cant
C
7.00E+00
6.80E+00
3.70E+00
3.20E+00
1.80E+00
2.30E+00
2.10E+00
3.30E+00
3.30E+00
1.60E-01
3.50E-09
1.40E+17
(Q S C '
Uw * DRng ;
DOT) - (Q ' S ' C ' UW
DFIng
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.SOE-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.SOE-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
>/R
RFIng ) / R
R
5.46E+02
5.46E+02
4.10E+02
1.64E+04
4.10E+02
1.64E+04
1.64E+04
2.74E-K02
2.74E+02
2.74E4-02
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PD
1.13E*04
3.11E+04
5.42E*03
3.59E+01
2.83E4-03
3.56E+01
1.59E+02
1.45E+03
1.29E4-03
6.77E+01
PR
1.72E-03
4.83E-03
8.34E-04
5.57E-06
4.44E-04
5.51 E-06
2.47E-05
2.22E-04
2.02E-04
1.05E-05
TOTAL 5.36E+04 8.30 E-03
A-134
-------
P4«
POPULATION - INGESTION OF RIVER
WATER CONTAMINATED BY SURFACE RUNOFF
ten Wmtur Tnmt Sfu03
8.18E>05
2.4SE+03
8.18EfOS
8.18E+05
2.46E+03
2.45E+03
2.4SE+03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PO
1.83E+02
2.89E+02
2.23E+02
2.56E-03
2.99E+02
3.53E-03
1.73E-02
1.12E+01
9.96E*00
8.07E-02
PR
79E-05
49E-05
43E-05
97E-10
70E-05
46E-10
S9E-09
71 E-06
5SE-06
26E-08
TOTAL
1.02E+03
57E-04
A-13S
-------
P4f
POPULATION - DIGESTION OF RIVER
WATER COMTAMMATED BY SURFACE RUNOFF
Ion Wmtor TfcMf Sludg* (LfndflH)
Q. 3.50E-09
S- 2.66E+16
PD(mram) - (G * S * C UW DFIng ) / R
PR(fatal cancan) - (Q * S * C * UW RFIng ) / R
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1.50E-01
1.50E-01
2.40E-01
3.00E-03
3.00E-01
3.00E-03
3.00E-03
6.00E-02
6.00E-02
5.00E-04
DFIna
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIng
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.73E+03
4.91 E+03
2.45E+03
8.18E+05
2.45E+03
8.18E+05
8.18E+05
2.45E+03
2.4SE*03
i45E*03
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
9.43E-01
9.39E-01
8.76E-01
8.76E-01
8.76E-01
PO
9.13E+00
1.44E+01
1.11E+01
1.28E-04
1.49E>01
1.76E-04
8.62E-04
5.57E-01
4.97E-01
4.48E-03
PR
1.39E-06
2.24E-06
1.71E-06
1.98E-11
2.35E-06
2.73E-1 1
1.34E-10
8.56E-08
7.76E-08
6.96E-10
TOTAL
5.07E>01 7.86E-06
A-136
-------
P4fl
POPULATION - INCESnON OF RIVER
WATER CONTAMINATED BY SURFACE RUNOF
ten MM;*/ Preceding Wm»t»
0. 3.50E-09
S- 6.86E+15
PCHmrem) . (Q S C Uw DRng ) / R
PR(fataJ cancan) - (Q S C * UW RFlng ) / R
Nuclld*
PO-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
2.50E+01
2.50E+01
3.50E+01
1.00E+01
1.00E+01
3.50E+01
1.00E+01
3.50E+01
3.50E+01
1.80E+00
DFIng
1 .90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.SOE-04
2.70E-04
RFInfl
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
R
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E^02
8.18E*04
8.18E+04
2.46E+02
2.46E-^03
2.46E+02
Uw
.43E-01
.43E-01
.43E-01
.39E-01
.39E-01
'.43E-01
.39E-01
.76E-01
.76E-01
.76E-01
PO
3.93E+03
6.21 E+03
4.19E>03
1.10E+00
1.28E+03
5.33E+00
7.44E+00
8.38E+02
7.48E+01
4.16E+01
PR
5.99E-04
9.66E-04
6.44E-04
1.71E-07
2.02E-04
8.23E-07
1.16E-06
1.29E-04
1.17E-05
6.46E-06
TOTAL
1.66E*04 2.56E-03
A-137
-------
P4h
POPULATION INGESTIONOF RIVER
WATER CONTAMINATED BY SURFACE RUNOFF
tor. Oil OM Seal* Sludg*
G. 3.50E-09
S- 5.24E+16
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
PEXmrem)
PR(fatal can
e
1.55E+02
1.5SE+02
1.55E+02
5.50E+01
5.50E+01
(Q 3 C *
can) . (Q *
DFIno
1.90E-03
5.40E-03
1 .30E-03
4.00E-04
1.40E-03
Uw'DFlng)
s c uw
RFInq
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
/R
RPIng )/R
R
5.46E+02
5.46E+02
1.36E+04
1.36E+04
1.36E+04
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
PD
9.33E+03
2.65E+04
2.56E+02
2.79E+01
9.75E+01
PR
1.42E-03
4.1 2E-03
3.94E-OS
4.32E-06
1.S3E-05
TOTAL 3.62E+04 5.61 E-03
A-138
-------
P4I POPULATION - INGESnON OF RIVER
WATER CONTAMINATED BY SURFACE RUNOFF
ten (teofftwiMf WM(*
G. 3.50E-09
S- 4.32E+15
PCKmram) . (Q S * C UW DFIng ) / R
PR(fata) cancan) - (G S C Uw RRng ) / R
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
e
1.10E+02
1.10E+02
1.60E+02
3.00E+01
1.10E+02
- .
. .
- -
DFInfl
1.90E-03
5.40E-03
1.30E-03
4.00E-04
1.40E-03
- -
- -
- -
- -
- -
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
-
- -
- -
- -
- -
R
2.74E+02
4.92E+02
2.46E+02
8.18E+04
2.46E+02
*
Uw
9.43E-01
9.43E-01
9.43E-01
9.39E-01
9.39E-01
- -
-
- -
- -
- -
PO
1.09E+04
1.72E+04
1.21E+04
2.08E+00
8.89E+03
-
-
-
PR
1.66E-03
2.68E-03
1.85E-03
3.23 E-0 7
1.40E-03
"
"
"
" "
- -
TOTAL 4.90E+04 7.59E-03
A-139
-------
P5C
POPULATION INGESTION OF FOODSTUFFS
GROWN ON REPEATEDLY FERTILIZED SOIL
Pho*phat» Fertilizer
(^ 4.93E+06
S.1.00E+00
PDOnrem) . (Q S C Uf DFing )
PR(latal cancers) - (Q S * C Ul * RRng )
Nuelld*
Po-210
Pb-210
Ra-226
Th-228
Ra-228
Th-230
Th-232
U-234
U-238
U-235
C
1 .80E-03
1 .80E-03
2.50E-03
3.40E-04
3.40E-04
1 .60E-02
3.10E-04
1 .70E-02
1 .70E-02
8.60E-04
DFInfl
1.90E-03
S.40E-03
1.30E-03
4.00E-04
1.40E-03
5.50E-04
2.70E-03
2.80E-04
2.50E-04
2.70E-04
RFIna
2.90E-10
8.40E-10
2.00E-10
6.20E-11
2.20E-10
8.50E-11
4.20E-10
4.30E-11
3.90E-11
4.20E-11
Uf
1.31E-02
1.31E-02
1.31E-02
1 .29E-02
1.29E-02
1.31E-02
1 .29E-02
2.21 E-02
2.21 E-02
2.21 E-02
PD
2.21 E-01
6.28E-01
2.10E-01
8.65E-03
3.03E-02
S.68E-01
S.32E-02
S.18E-01
4.63E-01
2.S3E-02
PR
3.37E-08
9.76E-08
3.23E-08
1 .34E-09
4.76E-09
8.78E-08
8.28E-09
7.96E-08
7.22E-08
3.94E-09
TOTAL 2.73E+00 4.22E-07
A-140
-------
PS*
lots \
POPULATION DIGESTION OF FOODSTUFFS
OJKMM ON REPEATEDLY FERTILIZED SOL
Tnmt Sludge
S-1.00E+00
P0(mr 01) . (Q S C Uf DFing )
PR
------- |