905R80132
              DRAFT
 ENVIRONMENTAL IMPACT STATEMENT
               FOR
    REMEDIAL ACTION STANDARDS
               FOR
INACTIVE URANIUM  PROCESSING SITES
           April 1980
  Office of Radiation Programs
 Environmental Protection Agency
     Washington, D.C.  20460
                    U.S.  Environmental Protection Agency.
                    Region V, Library
                    230  South Dearborn Street
                    Chicago,  Illinois   60604

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                                  FOREWORD

(X)  Draft Environmental Statement
( )  Final Environmental Statement

                       Environmental  Protection  Agency
                        Office of Radiation Programs

1.   This Environmental Impact Statement was prepared by the Criteria and
Standards Division (CSD), Office of Radiation Programs (ORP), U.S.
Environmental Protection Agency (EPA).

     Questions regarding this statement should be directed to Stanley
Lichtman, Project Manager.  Should there be questions regarding the
content of this Statement, Dr. Lichtman may be contacted in care of the
Director, Criteria & Standards Division or at (703) 557-8927.

2.   The Environmental Protection Agency (EPA) is proposing standards for
the disposal of uranium mill tailings from inactive processing sites, and
for cleanup of contaminated land and buildings.   These standards were
developed pursuant to the Uranium Mill Tailings Radiation Control Act of
1978 (PL 95-604).  The Act requires EPA to promulgate standards of general
application for the protection of the public health, safety, and the
environment from radiological and nonradiological hazards due to uranium
mill tailings at designated inactive sites.  The 25 sites initially
designated include inactive uranium mill tailings piles in the states of
Arizona, Colorado, Idaho, New Mexico, North Dakota, Oregon, Texas, Utah,
and Wyoming and the site of a former rare metals plant in Pennsylvania.

3.   In conducting the review for information, EPA staff meet with indi-
viduals and organizations to seek information and to ensure a thorough
understanding of the issues of concern.  On the basis of this and other
such activities or inquiries as are deemed useful and appropriate, the
staff makes an independent assessment of the considerations specified in
EPA's Regulation EIS Procedures (39 F.R. 37419,  October 21, 1974).

4.   This evaluation leads to the publication of a Draft Environmental
Impact Statement (DEIS), which is circulated to appropriate governmental
agencies for comment.  In preparing this DEIS, a great deal of information
was gained from reviewing the Generic Environmental Impact Statement on
Uranium Milling (NUREG-0511) prepared by the U.S. Nuclear Regulatory
Commission (NRC).  A summary notice will be published in the Federal
Register of the availability of the DEIS.  Interested persons are invited
to comment on the draft statement and the proposed standards.

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     Comments should be received by 	,  1980,  at the address shown
below.  Single copies of this statement may also be obtained from this
address:

     Director, Criteria and Standards Division
     Office of Radiation Programs (ANR-460)
     U.S. Environmental Protection Agency
     401 M Street,  S.W.
     Washington, D.C.  20460

5.   After considering comments on the Draft EIS, the Agency will prepare
a Final EIS (FEIS), which will include discussion of concerns raised by
the comments, and conclusions reached as a result of the comments.  The
Final Environmental Impact Statement will then  be released by the Agency.

6.   The following Federal agencies have been asked to comment on this
environmental statement:

     Department of the Army, Corp of Engineers
     Department of Commerce
     Department of the Interior
     Department of Health, Education & Welfare
     Federal Energy Regulatory Commission
     Department of Energy
     Department of Transportation
     Nuclear Regulatory Commission
     Department of Agriculture
     Advisory Council on Historic Preservation
     Department of Housing and Urban Development
     Department of Justice

     In addition, all State Clearinghouses have been sent copies of this
statement.

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                                 Contents
Summary	'	    S-1

1.  Introduction	    1-1

2.  A Brief History of Uranium  Milling Operations  	    2-1

3.  The Inactive Sites	    3-1
     3.1  The Phase I Studies	    3-2
     3.2  The Phase II Studies	    3-9
     3.3  Source Terms	3-10
         3.3.1  Radioactivity Source Terms 	   3-10
         3.3.2  Nonradiological Contaminants 	   3-16
         3.3.3  Off-Site Contamination 	   3-21

4.  Health Effects	    4-1
     4.1  Introduction	    4-1
     4.2  Radon and Its Immediate Decay Products 	    4-4
     4.3  Estimates of the Lung Cancer Risks From Inhaling Radon
            Decay Products	    4-7
     4.4  Impact on Local and Regional Population Due to Radon
            Decay Products	4-13
     4.5  Risks to the Continental U.S. Population Due to Radon
            Emission from Inactive Piles 	   4-24
     4.6  Regional and National Effects Due to Long Half-Life
            Radioactive Materials  	   4-28
     4.7  Impact From Gamma-Ray Exposures  	   4-31
     4.8  Hazard from Water Contamination  	   4-36
         4.8.1  Introduction	4-36
         4.8.2  Movement of Toxic Chemicals from Tailings  	   4-37
         4.8.3  Toxicity of Major Toxic Substances
                  Found in Tailings	4-40
              4.8.3.1  Arsenic  	   4-41
              4.8.3.2  Barium  	   4-42
              4.8.3.3  Cadmium  	   4-42
              4.8.3.4  Chromium  	   4-44
              4.8.3.5  Cyanide  	   4-44
              4.8.3.6  Iron	4-45
              4.8.3.7  Lead	4-45
              4.8.3.8  Mercury  	   4-46
              4.8.3.9  Molybdenum  	   4-47

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              4.8.3.10  Nitrate   	   4-48
              4.8.3.11  Radium 	   4-49
              4.8.3.12  Selenium 	   4-50
              4.8.3.13  Silver 	   4-50
              4.8.3.14  Thorium   	   4-51
              4.8.3.15  Uranium   	   4-52
              4.8.3.16  Vanadium 	   4-53
     4.9  Summary	4-54

5.  Alternative Tailings Disposal Control Levels 	    5-1
     5.1  Introduction	    5-1
     5.2  Control of Radon-222 Releases  	    5-3
         5.2.1  Radon Control	    5-3
         5.2.2  Effects of Radon Control  on Release  of
                  Airborne Particulates  	    5-7
         5.2.3  Effects of Radon Control  on Direct
                  Gamma Radiation	    5-8
         5.2.4  Effects of Radon Control  on Potential
                  Water Impacts	5-10
     5.3  Control of Surface and Ground Water Contamination  ....   5-11
     5.4  Longevity of Control	5-13
         5.4.1  Effects of Natural Forces  	   5-13
              5.4.1.1  Earthquakes 	   5-14
              5.4.1.2  Floods  	   5-15
              5.4.1.3  Windstorms and Tornadoes  	   5-16
              5.4.1.4  Glaciation  	   5-16
         5.4.2  Impacts of Human Activity  	   5-17
     5.5  Summary	5-22

6.  Monetary Costs and the Effects of Tailings Disposal  	    6-1
     6.1  Estimated Costs	    6-2
     6.2  Estimated Health Benefits  	    6-6
     6.3  Longevity of Control	    6-9
     6.4  Environmental Impacts  of Control Actions 	   6-12
     6.5  Occupational Hazards 	   6-13
     6.6  Economic Considerations at the  Local Level 	   6-14

7.  Considerations for Cleanup of Contaminated
      Land and Buildings	    7-1
     7.1  Introduction	    7-1
     7.2  Off-Site Contamination 	    7-2
     7.3  Potential Hazards of Off-Site Contamination  	    7-4
     7.4  Remedial Actions and Costs 	    7-7
     7.5  Previous Standards for Indoor Radon
            Decay Product Concentration  	    7-9
     7.6  Normal Indoor Radon Decay Product Concentrations 	   7-11
     7.7  Practicality of Alternative Remedial
            Action Standards for Buildings 	   7-14

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8.  Selection of Proposed Standards Among Alternatives 	    8-1
     8.1  Disposal Standards .	    8-2
         8.1.1  Radon Standard	    8-2
         8.1.2  Ground Water Standard  	    8-7
         8.1.3  Surface Water Protection 	   8-16
         8.1.4  Remedial Action for Existing
                  Water Contamination	8-18
         8.1.5  Period of Application of Disposal Standards  ....   8-18
     8.2  Cleanup Standards  	   8-21
         8.2.1  Open Lands	8-21
         8.2.2  Buildings	8-24
              8.2.2.1  Justification for the Proposed Indoor Radon
                         Decay  Product Concentration Standards .  . .   8-24
              8.2.2.2  Standards for Indoor Gamma Radiation  ....   8-27
              8.2.2.3  Radiation Hazards not Associated
                         with Radiuo-226	8-28

9.  Implementation	    9-1
     9.1  Administrative Process 	    9-1
         9.1.1  Disposal Standards 	    9-1
         9.1.2  Cleanup Standards  	    9-2
     9.2  Exceptions	    9-4
     9.3  The Effects of Implementing the Standards	    9-6
         9.3-1  Health	    9-6
         9.3-2  Environmental	    9-7
         9.3.3  Economic	    9-8
     9.4  The Proposed Standards	9-10

Appendix A - Comments	    A-1

Appendix B - Development of Cost Estimates	    B-1

Appendix C - The Proposed Standards	    C-1

Appendix D - Response to Comments	    D-1

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                                  Figures


                                                                      Page

3-1     Uranium-238 Decay Series 	   3-14

4-1     Lung Cancers as a Function of Cumulative WL  Months	    4-8

5-1     Percentage of Radon Penetration  	    5-6

5-2     Nominal Attenuation of Direct Gamma Radiation
          by Soil	    5-9

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                                  Tables


                                                                      Page

2-1   Number of Active and Inactive Uranium Mill Sites 	    2-4

3-1   Inactive Uranium Milling Sites 	    3-3

3-2   Summary of Conditions Noted at Time of Phase I Site
        Visits	    3-5

3-3   Summary of Phase I Findings and Principal Action to be
        Studied in Phase II	    3-8

3-4   Radioactivity in Inactive Uranium Mill Tailings
        Piles	    3-11,3-12

3-5   Elements and Compounds Measured in an Inactive
        Tailings Pile	3-17

3-6   Additional Elements and Compounds Found in Uranium
        Mill Tailings	3-18

3-7   Site-Specific Variability of Concentrations of
        Elements in Tailings Compared to Background Soil 	   3-20

3-8   Elements/Compounds Reported in Elevated Concentrations
        in Ground Water in the Vicinity of Tailings Piles  	   3-22

3-9   Gamma Radiation Anomalies and Causes 	  3-23,3-24,3-25

3-10  Contaminated Areas Around Inactive Uranium Mill
        Tailings Piles 	    3-27,3-28

4-1   Estimated Effect on Local and Regional Populations
        Due to Exposure from Radon Decay Products from
        Tailings Piles 	  4.15,4-16,4-17

4-2   Individual Risk Due to Lifetime Exposure to Radon
        Decay Products	4-19

4-3   Estimated Risk to Nearest Residents from Radon
        Decay Products	4-21

4-4   Risk Due to Background Radon in Residential Structures ....   4-23

4-5   Contribution of Inactive Uranium Tailing Piles to the
        National Health Risk from Radon Decay Products 	   4-26

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                                                                      Page

4-6   Summary Table — Inactive  Piles   	  .....   4-27

4-7   Regional Impact from Uranium Mill  Tailings  	   4-30

4-8   Increased Gamma Ray Dose Rates Due to  Inactive
        Tailings Piles 	   4-33

4-9   Estimated Lifetime Risk of Fatal  Cancer due to  Total
        Body Gamma-ray Exposure  at 100 mrad/yr	4-34

4-10  Estimated Risk of Serious  Genetic  Abnormalities  	   4-35

4-11  Summary — Risks Due to Radon Emission from Tailings  Piles  .  .   4-55

5-1   Nominal Half-Value-Layers  of Typical Natural Materials
        for Reducing Radon Releases  	    5-5

6-1   Ranges of Estimated Total  Cost by  Disposal  Option and
        Radon Control Level	    6-5

6-2   General Post-disposal Benefits of  Disposal  Options 	    6-8

7-1   Average Annual Radon Decay Product Concentrations in
        Normal Buildings 	   7-13

7-2   Experience with Grand Junction Remedial Action  Program  ....   7-15

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                                  SUMMARY








     The Environmental Protection Agency (EPA) is proposing standards for




the disposal of uranium mill tailings from inactive processing sites and




for cleanup of contaminated open land and buildings.  These standards were




developed pursuant to the Uranium Mill Tailings Radiation Control Act of




1978 (Public Law 95-604).  This Act requires EPA to promulgate standards




of general application for the protection of the public health, safety,



and the environment from radiological and nonradiological hazards due to




uranium mill tailings at designated inactive processing sites.  The 25




sites initially designated include inactive uranium mill tailings piles in



the States of Arizona, Colorado, Idaho, New Mexico, North Dakota, Oregon,



Texas,  Utah, and Wyoming and the site of a former rare metals plant in




Pennsylvania.








1.   The Proposed Standards Cover Two Situations




     a.  Disposal of Tailings:




     The standards limit release of radon gas to the air from disposed



tailings to 2 pCi/m2-sec; this is about twice the average radon released



from normal soil.  When the radon from a cover of normal soil is added to



that allowed from the tailings, the resulting release will still be within




a normal range of variation.  Ground water which is suitable for drinking



is subject to contamination limits which preserve this suitability.




Potentially useful ground water of lesser quality and surface waters are



protected against degradation.  The standards also require the disposal

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methods to provide a reasonable expectation of effectiveness for at least




1000 years.








     b.  Cleanup of Contaminated Open Land and Buildings:




     The standards require remedial action for open land contaminated by




tailings when the average radium concentration attributable to tailings




exceeds 5 pCi/gm.  This is 3-5 times the average concentration over the




full thickness of U.S. soils, but any residual contamination will usually



be only a thin layer.  This limits present and future radiation exposures



from tailings which have been dispersed.  The radiation from land which



satisfies the standard will be within the normal variations that occur



among undisturbed land areas.








     Remedial actions are also be required for any occupied or occupiable




building in which the radon decay product concentration is more than



0.015 WL (including background), or the gamma radiation exposure rate is



more than 0.02 mR/hr above background, due to uranium mill tailings.








2.   Summary of Environmental Impacts




     Implementing the disposal standards at all designated sites would



prevent an estimated total of about 200 premature deaths due to radiation-




induced lung cancer in each century for as long as they are effective.  We




further require disposal methods to provide a reasonable expectation that




the standards will be satisfied for at least  1000 years.  About 140 of




these deaths would be expected in the populations within 50 miles of the
                                   S-2

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inactive tailings piles and the rest in the remaining continental U.S.




population.   Health effects due to contamination of ground water resources



are not included in the above estimate.








     Estimates of the reduction in health effects that would result from




implementing the cleanup standards have not been made.  The benefits would




include not  only the prevention of adverse health effects, but also the




reclamation  of lands currently contaminated and unfit for unrestricted




use.








     Costs of implementing the standards have been estimated.  For an




average inactive uranium mill tailings pile, the estimated cost of meeting




the disposal standard ranges from about $1 million to over $13 million,



depending on the control methods used.  The cost of remedial action for




buildings in the Grand Junction cleanup program (which was authorized by




Congress in  1972 under PL 92-314) have been about $13,500 for a residential



structure, and about $38,500 for a commercial building.  The entire cost of



the cleanup  and disposal programs under PL 95-604 probably will be




$200-300 million.  These expenditures could have beneficial impacts on  the



local economies, and no perceptable effect on the national economy.
                                   S-3

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3.   Alternatives Considered



     With regard to the form and content of the standards,  the following




major alternatives were considered:








     a.  Disposal Standards




         There are four basic pathways of potential impact  on people and




     the environment from uncontrolled uranium mill tailings piles:








         (1)  Release of radon-222 into the atmosphere.




         (2)  Release of airborne particulates by resuspension of the



              tailings.



         (3)  Direct gamma radiation exposure from the tailings.




         (4)  Release of tailings or its radioactive and nonradioactive



              contaminants to surface or ground water through erosion or



              leaching.








     Standards of general application for the protection of the public




health, safety, and the environment must be based on the reasonableness




and feasibility of controlling these potential hazards.   Because of the



long lifetimes of the radioactive contaminants and the presence of



permanently toxic nonradioactive contaminants in tailings material,  it is



important to consider the longevity or permanence of control methods.








     The predominant health impact results from release of radon-222 into




the atmosphere.  We conclude that techniques which provide a reasonable

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degree of control of radon releases, and which have lasting effectiveness,




will also provide essentially complete control of particulate releases and




direct gamma radiation.  Therefore, control of particulates and direct



gamma radiation are not addressed specifically.  Alternatives for control



are discussed for only the radon-222 releases and the water pathway.




Alternative requirements for the longevity of control are also presented.








     For purposes of comparing costs, benefits, feasibility, longevity,




and other factors in developing an appropriate standard, three levels of




control are examined:








     (1)  No control (the existing situation).




     (2)  Control radon releases to about the natural background rate.




     (3)  Complete control (practically no release).








Significant control of radon was found justified due to the substantially



elevated radiation risk to persons who might reside near uncontrolled



piles, as well as due to the cumulative long-distance and long-term



effects of radon emissions.  A standard to require virtually complete



radon control was not found warranted because the practicality of reducing



radon emissions from tailings to levels well below those of normal soil is



questionable; the benefit of doing so is only a small additional reduction



in overall risk obtained at relatively high cost.  The proposed standards



require radon releases within the range of variation found in normal soils.
                                   S-5

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     Alternatives for the degree of control of potential water contamination



also range from no additional control to complete prevention.   For water,




the levels of control examined are:








     (1)  No control (the existing situation).



     (2)  Control of water contamination to a degree comparable to other




         water quality programs.




     (3)  Complete control (no contamination of water).








We conclude that the standards should protect water quality.  The potential



effects of mill tailings on surface and ground water quality are highly




site-specific.  Under some conditions, ground water could be made unusable



over an area much larger than the pile.  The likelihood of this occurring




at the existing inactive mill sites has not been thoroughly examined.




Available information about the inactive mill sites suggests that special




measures to protect ground water often will not be needed.  However, where



the standards might be exceeded only in the immediate neighborhood of a



pile, we do not believe the substantial costs and disruptions necessary to




avoid the violation would be warranted.  Therefore, when existing sites are



used for disposal, we propose to apply ground water protection standards



1.0 kilometer from the pile.  If tailings are moved to a new disposal site,



for whatever reason, we propose to apply the standards 0.1 kilometer from




the pile.
                                   S-6

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     The standards provide that tailings disposal will not cause ground




water concentrations to exceed specified levels.  If the ground water



already exceeds these concentrations for other causes than tailings, then




no further degradation is allowed.  Ground water contamination already may



have occurred at some of the piles.  It is sometimes possible to reduce




such contamination in aquifers, but we feel a generally applicable require-




ment to do so is not feasible.  Therefore, the proposed ground water




standards do not apply to materials already released from the tailings.








     Implementing the radon release and ground water protection standards




should provide adequate protection for surface water, so explicit




standards may not be needed.  However, to assure adequate protection, we




propose to require that surface water not be degraded by tailings after




disposal of the piles.








     Requirements for how long control should be effective could range from



a few years to as long as the tailings remain potentially hazardous.  The




health protection the disposal system ultimately affords depends on the




control levels and the time over which they are maintained.  We examined



technical and economic factors which determine the feasibility of



controlling tailings for various times.








     Congress recognized that the dangers of uranium mill tailings are




long-term, and directed EPA to set reasonable standards for their long-term




disposal.  We propose requiring a reasonable expectation that the radon
                                   S-7

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emission and water protection standards for disposal of tailings piles



will be satisfied for at least 1000 years.   Institutional control methods




such as record-keeping, maintenance, and land-use restrictions are useful




adjuncts to an adequate disposal system, to provide greater protection




than the standards require.  They are inappropriate for a primary role in



long-term control, however, and should not replace adequate long-term




physical disposal methods.








     The choice of a 1000-year period results from practical considerations




for uranium mill tailings.  Technically and economically reasonable



disposal methods may, in some instances, be expected to protect for longer




than 1000 years.  A 1000-year standard does not mean our concern for the




future is limited, but does reflect our judgment that the disposal



standards must be practical.








     b.  Cleanup Standards:




     Uranium mill tailings from inactive sites have been spread by wind,




water, and people to nearby and distant locations.  Therefore, standards



for cleanup of tailings must address the following situations:








     (1)  Tailings have spread different distances from different piles,



occur at various depths in the soil, and are mixed with various materials.




The standard must specify the quantity or concentration of tailings which




requires cleanup.
                                   S-8

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     (2)  Because radionuclides leak into the soil under the piles, if




these piles are removed the maximum allowable residual level of



radioactivity in the subsoil must be specified.








     (3)  Tailings that have been used as landfill or in building




materials, or have accumulated around a structure are particularly




hazardous.  Building interiors have limited airflow and radon decay product




concentrations in them may be many times the outdoor levels.  Thus, the




standard must specify the maximum allowable radon decay product concentra-




tion in buildings.  The cleanup standard for open land must consider the



possibility of future building on the land.








     The indoor radon decay product concentration in a building will




depend on the radium concentration in the soil under or adjacent to it,




regardless of whether the radium is naturally-present or is a contaminant.




However, so many other factors affect the indoor radon decay product




concentration that a useful correlation with the radium in soil is




difficult to establish.  Under some conditions, radium concentrations as



low as 1-5 pCi/gm in natural or contaminated soil can produce indoor radon



decay product concentrations exceeding 0.01 WL.  Common natural soils have



radium concentrations near the lower end of this range.








     Natural or contaminated soils with radium concentrations of 5 pCi/gm




through several feet down can also give exposure rates from gamma radiation




of about 80 mR/yr.  Exposure rates are proportionately higher or lower for
                                   S-9

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other concentrations, and decrease as the layer of radium-containing



material becomes thinner, or is covered over by other materials.








     The proposed standard requires that for any open land contaminated




with tailings, the average radium concentration in any 5-centimeter




thickness shall not be more than 5 pCi/gm after cleanup.  The proposed




standard is EPA's judgment of the most stringent cleanup condition that




may reasonably be required uniformly for all the inactive mill sites.




After the required cleanup, radon emission and gamma radiation from the




site will be within the normal variations that occur among nearby



undisturbed land areas.








     Exposure to even normal indoor radon decay product concentrations



carries some health risk, but we believe Congress intended that people



should not have to bear an unreasonable increase in this risk due to




tailings.  However, indoor radon decay products in normal buildings vary



widely, and depend on many factors.  We considered alternative forms for a




remedial action standard for indoor radon decay products, but decided that




a limit on the total concentration is the only workable form.  We believe



that the proposed remedial action level of 0.015 WL (including background)



for occupied or occupiable buildings is the most protective level that can



be justified.  Experience in the Grand Junction program and studies per-




formed by EPA for homes  in Florida indicate that remedying concentrations




greater than 0.015 WL is usually practical.  However, we have concluded




from studies of radon decay product concentrations in normal houses that
                                   S-10

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^^      efforts to reduce levels significantly below 0.015 WL by removing tailings



         would often be unfruitful, and the funds expended wasted.
              The proposed limit on indoor radon decay product concentration is



         based on the hazard from breathing air containing these products.  Tailings




         also emit gamma radiation, however, which can penetrate the body from the




         outside.  We expect the indoor radon decay product standards generally will




         be met by removing tailings from the building, and this will eliminate any



         indoor gamma radiation problem.  For some buildings, however, complete




         tailings removal may not be a practical means of lowering the indoor radon



         decay product concentration, more for engineering reasons than for cost.




         Alternate methods, such as air cleaning, improving ventilation, or applying




         sealants to the walls and floors are available.  If these are used,



         standards will be needed to limit gamma radiation exposure of the



         occupants.








              If the gamma radiation standard is set too high, then radon decay




         product reduction methods for buildings other than removal of tailings




         would more often be possible.  Removal is the remedial method we wish most



         to encourage, however, because of its positive and long lasting



         effectiveness.  To this end, our proposed action level for gamma radiation



         of 0.02 mR/hr above background allows a limited degree of flexibility in



         the methods for reducing indoor radon decay product concentrations.  On




         the other hand, reducing the standard much below 0.02 mR/hr would virtually




         eliminate flexibility in remedial methods, and provide only a small



         additional health benefit to those few individuals who might be affected.






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     The proposed standards will be implemented by the Department of



Energy, in cooperation with other Federal agencies,  and affected States




and Indian tribes.  Because we expect there will be exceptional circum-




stances for which the proposed standards are unreasonable,  we have



provided criteria for deciding when exceptions to the standards may be




justified.  Under such exceptional circumstances, DOE, with the




concurrence of NRC, may select and perform remedial actions which come as




close to meeting the standards as is reasonable.
                                   S-12

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1.   INTRODUCTION








     In Public Law 95-604,  the Uranium Mill Tailings Radiation Control




Act of 1978 (42 USC 7901),  the Congress found that uranium mill tailings




located at active and inactive mill operations may pose a potential and




significant radiation health hazard to the public.  The Congress also



concluded that the protection of the public health, safety, and welfare




requires that every reasonable effort be made to provide for the




stabilization, disposal, and control of such tailings in a safe and




environmentally sound manner, in order to prevent or minimize radon




diffusion into the environment, and to prevent or minimize other




environmental hazards from tailings.








     The Act requires the Administrator of the Environmental Protection




Agency to promulgate standards of general application that will protect



the public health, safety,  and the environment from radiological and




nonradiological hazards associated with residual radioactive materials



located at inactive uranium mill tailings sites and at depository sites



for such materials.  "Residual radioactive material" is defined as



(1) waste, which the Secretary of Energy determines to be radioactive, in



the form of tailings from the process of extracting uranium and other



valuable constituents from ores; and (2) other waste, which the Secretary




of Energy determines to be radioactive, which relates to such processing,



including any residual stocks of unprocessed ores or low grade materials



at a processing site.  The Act also requires the Administrator to




promulgate such standards of general application for active uranium mill

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sites and disposal sites.   In this environmental impact statement we

examine proposed standards of general application which would govern

remedial action for open lands and structures contaminated with residual

radioactive material, mainly tailings or other wastes presenting similar

hazards, as well as the long-term stabilization of uranium mill tailings

from inactive processing sites.  Standards applicable to active sites

will be proposed later.



     The Uranium Mill Tailings Radiation Control Act of 1978 (hereafter

referred to as PL 95-604)  specifies 22 inactive processing sites to be

addressed by these standards.  Twenty-one are inactive uranium mill sites

located in the western United States, and the other is a former rare

metals processing site in Canonsburg, Pa.  This Environmental Impact

Statement primarily applies to the milling sites, but also contains

information on the Canonsburg site.  Although that site differs in many

respects from the western milling sites, the potential hazards, and many

of the remedial and control methods described in this statement, are

applicable1.
 1 Under the directive of Sec. 102 of PL 95-604 the Department of Energy
 has formally designated the 22 sites, and has also designated 3 additional
 processing sites that require remedial action.  These are located near
 Bowman and Belfield, North Dakota, and Baggs, Wyoming.  The 3 newly-added
 sites have only recently been characterized, and they appear to be among
 the least hazardous in the entire group (see "Uranium Mill Tailings Site
 Visit and Preliminary Health Impact Evaluation", a report prepared by
 Ford, Bacon and Davis Utah Inc., October 17, 1979).  Data on these three
 sites is much less complete than for the other designated sites, so we have
 not included them in our analysis.  It is clear, however, that omitting
 these three small sites could not materially affect our conclusions.
                                    1-2

-------
     In developing the proposed standards,  we first evaluated the



potential effects on public health and the  environment of uranium mill




tailings at designated sites.  General approaches to control these



impacts were then reviewed.  Estimates of the range in costs of control




and disposal were developed, based on consideration of specific methods



available to reduce or eliminate these impacts.  Consideration of the



benefits of control in terms of reduced health impact, longevity of these




methods, the limitations of institutional control, costs, feasibility,




and the potential impact of the control methods themselves, led to the




selection of the proposed standards.  Under PL 95-604, implementation of




these standards of general application is the responsibility of the



Department of Energy and the Nuclear Regulatory Commission.








     A brief history of the uranium milling industry is given in Chapter 2




to provide some background.  Chapter 3 presents a review of the




information available on designated inactive processing sites, a summary




of their radiological and nonradiological characterictics, and



information on off-site contamination of land and structures near these



sites.  Chapter 4 is a general discussion of potential health hazards



resulting from uranium mill tailings with estimates of the risks to



people living nearby, in the region, and in the continental United




States.  Chapter 5 is a consideration of alternative degrees of control.



In Chapter 6 we present monetary cost estimates for typical engineering




methods of achieving various levels of control.  Other significant



aspects of control, such as longevity and effectiveness, and occupational
                                    1-3

-------
hazards, are also discussed.  Chapter 7 addresses the specific problem of



off-site contamination, and the considerations for remedial action to




clean up contaminated land and structures.  Selection of proposed



standards is discussed in Chapter 8.  Chapter 9 discusses the process and




expected effects of implementing the standards.
                                     1-4

-------
2.   A BRIEF HISTORY OF URANIUM MILLING OPERATIONS



     The Nuclear Regulatory Commission (NRC),  in its Draft Generic

Environmental Impact Statement on Uranium Milling (NR 79), has presented

a brief history of uranium milling operations, summarized from a

publication by Merritt (ME 71).  Because of its relevance, that summary

is repeated here.
     "In the past 35 years the uranium industry has undergone a
     series of transformations, the element changing almost
     overnight from a commodity of only minor commercial interest
     to one vital for nuclear weapons and, now, to its important
     peaceful use as a fuel for generation of electrical energy.
     With each change there has been a surge of interest in ore
     exploration and development, and in new and expanded
     production facilities.

     "The military demand for uranium beginning in the early
     1940s had to be met from known sources of supply.  The rich
     pitchblende ores of the Shinkolobwe deposit in the Belgian
     Congo and the Great Bear Lake deposit in Canada supplied
     uranium during the war years and were supplemented by
     production from treatment of old tailings dumps and a few
     small mines in the Colorado Plateau area.  These high-grade
     ores and concentrates were refined by an ether extraction
     technique adapted from analytical procedures.  Crude ore
     milling processes for low-grade ores used during this period
     reflected little change from methods used 40 years earlier
     (at the turn of the last century) with uranium recovery from
     the leach solutions based on several stages of selective
     precipitation.  Milling costs were high and overall recovery
     was low, as judged by current standards.

     "With passage of the Atomic Energy Act of 1946, a strong
     emphasis was placed on the discovery and development of new
     worldwide sources of uranium.  At the same time, the
     research efforts begun earlier were expanded in scope and
     magnitude to advance the process technology.  These efforts
     led to greater use of lower grade ores than previously had
     been considered feasible, such as the uranium-bearing gold
     ores in South Africa, as a source of uranium, and to the
     discovery and development of large, low-grade deposit in the
     Beaverlodge, Elliot Lake, and Bancroft regions of Canada.

-------
"In the United States, prospecting and mining for uranium
were encouraged by the Atomic Energy Commission (AEC)
through guaranteed fixed prices for ore,  bonuses, haulage
allowances, establishment of ore-buying stations and access
roads, and other forms of assistance.  These incentives led
directly to an increase in the known mineable reserves of
ore in the western United States from about 9 x 105 metric
tons (MT) (1 x 106 short tons (ST)) in 1946 to 8.1 x 10?
MT (8.9 x 10? ST) in 1959.  Programs also were initiated
to examine other possible sources of uranium and to develop
methods for processing these materials.  AEC purchases from
19^8 through 1970 totalled approximately 3 x 105 MT (3.3 x
105 ST) of U30s, of which nearly 1.6 x 105 MT (1.8 x
105 ST) with a value of about $3 billion were supplied
from domestic sources.

"Mill process development programs in the United States were
sponsored by the Manhattan Engineering District, and later
by the AEC, through contracts with over 20 organizations
from 1944 through 1958.  Similar efforts were begun almost
simultaneously in other countries, and the cooperative
efforts and free exchange of information, particularly with
Great Britain, the Union of South Africa, Canada, and
Australia, greatly aided the overall effort.  Many privately
owned companies interested in mining and milling of uranium
also contributed to the knowledge gained during this
period.  Major developments included progress in chemical
flocculents and in techniques for making liquid-solid
separations.  Studies of variables in the leaching circuit,
such as ore particle size, the effect of the state of
oxidation of the uranium in the ore on rate of dissolution,
the use of oxidants, temperature, time of contact, etc.,
assisted in improving the efficiency of this operation and
permitted the treatment of a greater variety of ores with
consistently high recovery.  Developments in operating
techniques and in equipment design contributed to process
reliability and to the production of final concentrates of
relatively high purity.  Dry grinding was used in the early
mills but was gradually replaced with more efficient wet
grinding, which also reduced dusting.  The entire
development period was marked by steadily decreasing process
costs per unit of production.

"During the peak production years in the United States, from
1960 through 1962, the number of operating mills  (excluding
plants producing by-product uranium from phosphates) varied
from 24 to 26, with total annual production exceeding 1.5 x
104 MT (1.7 x 104 ST) of l^Oe from the treatment of
about 7 x  106 MT (8 x  106 ST) of ore.
                              2-2

-------
     "In 1957 it was apparent that very large ore reserves had
     been developed, and that additional contracts,  which were
     the main incentive for exploration by potential producers,
     would lead to commitments exceeding government  requirements
     through 1966.  In 1958, the AEC withdrew its offer to
     purchase uranium from any ore reserves developed in the
     future.  This led to shutdowns of mills after expiration of
     contracts and to stretching out of deliveries under
     long-term contracts in the United States, Canada, and South
     Africa.  As a result of these attempts to balance lowered
     military demand and slow development of commercial reactors
     with an overexpanded supply, the period from 196? through
     1970 saw a considerable reduction in the number and
     production rates of active uranium mills in the U.S. and
     abroad.  However, contracts with many U.S. producers were
     eventually extended through 1970.  These contract
     stretchouts reduced the rate of government purchases and
     constrained production to values more in line with
     government requirements.  They also served to ease the
     industry through a period when nuclear power growth had not
     progressed sufficiently to create a significant commercial
     demand.

     "Total production of UoOg through 1977 from U.S. sources
     is estimated at about 2.7 x 10)5 MT (3 x 10^ ST).  The
     amounts of ore used in the production of this U^QS, and
     the approximate amount of tailings produced, were expected
     to reach 1.3 x 108 MT (1.4 x 108 ST) by the end of
     1977.  Of this total, about 20%, or 2.3 x 10)7 MT (2.5 x
     107 ST), is located at inactive mill sites and  the balance
     (80/O is located at currently active mill sites."
     The development of nuclear power in the 70's,  and projections of the

future need for nuclear fuel spurred increased exploration for ore and

construction of mills in the late 70's.



     Table 2-1 shows the number of active and inactive uranium milling

sites in the United States by five-year intervals.   This listing does not

include several pilot plants and mills that produced uranium prior to

1950.
                                  2-3

-------
                             TABLE 2-1


          Number of Active and Inactive Uranium Mill Sites a
Year No.
Up thru 1940
1945
1950
1955
1960
1965
1970
1975
1980 (Jan)
of Active Sites
4
5
9
12
30
21
15
15
2!(b)
No. of Inactive Sites
0
1
1
2
4
13
20
24
25
Total
4
6
10
14
34
34
35
39
46(b
     References JO 77,  AU 70,  and TH 79.

    included are 8 solution mining operations,  4  phosphoric  acid
by-product plants, and  4 heap  leaching operations.
                               2-4

-------
     The hazardous nature of uranium mill tailings was not fully



recognized during the early years of the uranium industry.  Furthermore,




although the operation of uranium mills was licensable under the Atomic



Energy Act of 1954, tailings were exempt.  Numerous studies have been




done to assess the hazards of uranium mill tailings, and several State



(e.g., Colorado) and Federal agencies recognized the need for control.




However, a comprehensive program to address the hazards and require




control was not begun until 1974, after hearings held by the Congressional




Subcommittee on Raw Materials of the Joint Committee on Atomic Energy.




As a result of these hearings, studies supported by the Energy Research




and Development Administration (succeeded by the Department of Energy)




were undertaken to determine the status and general scope of the hazards




at inactive uranium mill tailings sites (Phase I), and to more fully




assess the hazards and alternatives for control (Phase II).
                                  2-5

-------
                         References for Chapter 2
(AU 70)   Augustine,  R.J.,  August  1970,  "Inventory  of Active Uranium Mills
         and Tailings Piles at Former Uranium  Mills,"  ISDHEW.

(JO 77)   Jones,  J.Q.,  October  1977,  "Uranium Processing Developments,"
         Grand Junction Office, Department  of  Energy.

(ME 71)   Merritt,  R.C.,  1971,  "The  Extraction  Metalurgy of Uranium,"
         Colorado  School of Mines Research  Institute,  Golden,  Colorado.

(NR 79)   U.S. Nuclear Regulatory  Commission, "Generic  Environmental
         Impact Statement on Uranium Milling," April 1979, NUREG-0511.

(TH 79)   Personal  Conversation with John Themelis,  October 1977,  Grand
         Junction  Office,  Department of Energy.
                                  2-6

-------
3.   THE INACTIVE SITES








     On March 12, 1974, hearings were held by the Subcommittee on Raw




Materials of the Joint Committee on Atomic Energy on identical bills




S. 2566 and H.R. 11378.  These bills proposed a joint effort by the U.S.




Atomic Energy Commission (later the Energy Research and Development




Administration and now the Department of Energy) and the State of Utah to




assess and take appropriate remedial action to limit the exposure of




persons to radiation originating from the Vitro uranium mill tailings site




at Salt Lake City, Utah.








     EPA supported the objectives of the proposed bills, but recommended




to defer remedial action for two reasons.  First, more information was




needed regarding possible remedial actions at the Vitro site.  More




importantly, the scope of problems and required remedial actions at all




other inactive mill sites needed to be determined, so that legislation




could provide for controls at all sites.  EPA and AEC proposed compre-




hensive studies to be made for all inactive uranium mill sites as a




cooperative effort among the states, EPA, and AEC.








     The first part of the studies (Phase I) were to establish the




condition, ownership and surroundings of the sites, and determine the need




for more detailed assessments.  The second part (Phase II) was to evaluate




the hazards, and analyze alternate solutions and their costs.  The Phase I




studies were begun in May 1974.

-------
3.1  The Phase I Studies

     The Phase I studies conducted during 1974 provided a summary of

conditions at each of the inactive sites and recommendations for the

detailed engineering assessments to be performed in Phase II.  Of the 25

inactive mill sites, 21 were included under Phase I, as Table 3-1

indicates, and four sites were not.  Those not included are at Monticello

and Hite, Utah; Edgemont, South Dakota; and Riverton, Wyoming.  (See the

footnote in Chapter 1, however.)



     The site at Monticello, Utah, is owned by DOE and the site at

Edgemont, South Dakota, is owned by TVA.  The site at Hite, Utah, after

removal of quantities of high grade tailings, was flooded when Lake Powell

was created by the Glen Canyon Dam in 1963.  At the time of the Phase I

study, the site at Riverton was still under license by the AEC, and

tailings stabilization was the responsibility of the licensee.  (This site

was added to the Phase II studies.)  The following discussion is taken

from the Summary of the Phase I reports (AE 74).  As an example of

information found in these reports, we present here the site description

given for the Vitro site at Salt Lake City, Utah, as well as

stabilization, off-site radiation, and use of mill sites found elsewhere

in the Phase I studies:



     The Vitro Site, Salt Lake City

     "The existing conditions at the Vitro site in Salt Lake City
     are completely unsatisfactory.  The tailings pile, located
     at the center of population of Salt Lake valley, is largely
     uncovered and subject to continuing wind and water erosion.
     While the extent of exposure of the population to radiation


                                    3-2

-------
                              TABLE  3-1

                    Inactive Uranium Milling Sites

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13-
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.

Site
Salt Lake City, Utah
Green River, Utah
Mexican Hat, Utah
Monticello, Utah(a)
Hite, Utah(o)
Durango, Colorado
Grand Junction, Colorado
Gunnison, Colorado
Rifle (Old), Colorado
Rifle (New), Colorado
Naturita, Colorado
Maybell, Colorado
Slick Rock (NC) , Colorado
Slick Rock (NCC), Colorado
Shiprock, New Mexico
Ambrosia Lake, New Mexico
Riverton, Wyoming
Converse County, Wyoming
Lakeview, Oregon
Falls City, Texas
Ray Point, Texas(c)
Tuba City, Arizona
Monument Valley, Arizona
Lowman, Idaho
Edgemont, South Dakota(d)
Canonsburg, Pennsylvania^6)
TOTALS
Phase I
X
X
X
——
——
X
X
X
X
X
X
X
X
X
X
X
—
X
X
X
X
X
X
X
— B —
_..
~5T
Phase II
X
X
X
__
	
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
»•.
x(f)
•23
Included In
PL 95-604
X
X
X
__
—
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
—
X
X
X
«- —
X
-V
Owned by DOE
Covered by waters of Lake Powell
Uranium not sold to U.S. Government
Owned by TVA
Not an inactive uranium mill site
Study was done as part of Formerly Utilized MED/AEC Sites
  Remedial Action Program
                                 3-3

-------
from this source may be difficult to quantify, the spread of
radioactivity is readily detectable for considerable
distances offsite.  Because of the continued industrial
growth in the area, the population exposure can be expected
to increase.  The site is only partially fenced and is
readily accessible to the public.  If the tailings pile were
to be stabilized by covering and vegetation at the present
site, their integrity would be difficult to maintain.  While
contamination of surroundings from blowing dust could be
reasonably well controlled, the emanation of radon gas and
leaching of radium into ground waters would be expected to
continue.  The representatives of AEC, EPA and the State of
Utah concur that the present site is unsuited to long-term
radioactive tailings storage, and the Phase II study of the
Vitro site should be directed principally toward a plan for
removal to a more suitable location.

Stabilization

"The conditions found at the 21 mill sites are summarized in
(Table 3-2).  Tailings stabilization at six sites had not
been attempted at all.  However, following the site visit,
the State of Oregon notified the owner that stabilization
should be undertaken as soon as possible at Lakeview.  The
chemical surface coating used at Tuba City, Arizona, has
broken up after only a few years weathering and is
considered unsuccessful.  The conditions at Shiprock, New
Mexico, on the Navajo Reservation have been considerably
aggravated as a result of the operation of a heavy earth
moving equipment school on the site.

"The State of Colorado adopted regulations in 1966 for
stabilization and control of uranium mill tailings by the
mill owners.  The substantial efforts made in that state
have been fairly successful.  In no case, however, was it
found that the results could be considered entirely
satisfactory.  Some erosion and loss of cover was noted in
all cases, and the vegetation was generally not self-
sustaining without continued maintenance, usually including
watering and fertilization.  Thus, the stabilization work
done to date represents a holding action, sufficient for the
present, but not a satisfactory answer for long-term storage.

Offsite Radiation

"The mechanisms known to cause spread of radioactivity from
the sites are:

1.  Wind blown solids.
2.  Radon gas and its decay products.

-------
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3«  Deliberate removal of tailings and other materials for
    offsite use.
4.  Water erosion and dissolution.
5.  Ground water and soil contamination.

"In addition, low grade ores and mine wastes have
occasionally been spilled or dumped offsite.

"Evidence exists of all these mechanisms causing some degree
of increase in radioactivity above natural background.  In
no other location was there evidence of the widespread use
of tailings in building construction such as occurred in
Grand Junction, Colorado.  Nevertheless, there are some
habitable structures in several other locations where
tailings use is suspected.

"Measurements of dust concentrations in air made near
tailings piles in the past have not indicated significant
hazard from inhalation.  However, the significance of
blowing dusts settling out in the general vicinity over a
period of many years has not been thoroughly evaluated.

"The EPA has held the position for sometime that radon gas
emanating from a tailings pile may cause a detectable
increase in airborne radiation levels in the vicinity of a
tailings pile, roughly within half a mile.  The gas will
diffuse readily into existing structures, but its
particulate decay products would tend to remain inside,
possibly causing a buildup in radioactivity within the
structure.  There is little data available to support this
hypothesis, but it needs to be checked carefully, as it
could have significant bearing on decisions regarding
removal of tailings piles from populous areas.  High radon
decay product levels were found in structures close to the
Vitro pile, but the possibility of their having been built
over tailings has not been excluded.

"Water erosion does not appear to have been a significant
factor in the off site migration of tailings.  However, the
movement of radium and soluble salts into the sub-soil in
areas with high water table needs further evaluation.  In a
few locations tailings piles are located near water courses
where flooding can be a problem.

Use of Mill Sites

"Where housing and other structures remain from the milling
operations they have been frequently put to use.  Housing at
Tuba City, Naturita, Slick Rock, Shiprock and Mexican Hat is
                               3-6

-------
     occupied.  Buildings on the mill sites at Gunnison,
     Naturita, Shiprock,  Green River and Mexican Hat are  being
     used for warehousing,  schools and other purposes.  At
     several sites,  buildings are still used for company
     activities.  At Salt Lake City a sewage disposal plant is
     operating on the site.  Construction of an automobile race
     track was begun in the middle of the tailings pile.   It was
     subsequently stopped by the State upon recommendations of
     AEC and EPA.  The pressure for use of sites in urban areas
     is likely to increase with time consistent with projected
     population growth.  None of the areas formerly occupied by
     milling facilities,  ore stockpiles, etc., have been  examined
     to determine the depth of soil contamination, or suitability
     for future unrestricted use."
     Table 3-2 gives a summary of the widely varying conditions noted at

the time of the Phase I site visits (AE 74,  Table I).  Table 3-3 summarizes

the October 1974 findings of the Phase I studies and presents the

recommendations made for Phase II studies of potential remedial actions

(AE 74, Table II).  Subsequent to the Phase I studies, the Naturita pile

has been moved, and the Shiprock site has been cleaned up and the pile

stabilized.  Additional information also indicates the presence of wind

and water erosion of tailings at all of the  sites, and removal of tailings

for construction uses from the Monument Valley,  Falls City,  and Ray Point

sites.  The status of buildings and other features has also changed at a

number of the sites.
                                    3-7

-------
                                                                TABLE 3-3

                                 SUMMARY OF PHASE  I  FINDINGS AND  PRINCIPAL  ACTION TO BE STUDIED IN PHASE II

                                                      AS DETERMINED  BY  AEC (NOW DOE)
Years Operated
Arizona
Monument
Tuba City
Colorado
Du range
Grand Junction
Gunnlson
Maybell
Naturlta
New Rifle
Old Rifle
Slick Rock (NO
Slick Rock (UCC)
Idaho
Lowman
New Mexico
Ambrosia Lake
Shiproek
Oregon
Lakeview
Texas
Falls City
Ray Point
Utah
Green River
Mexican Hat
Salt Lake City
Wyoming
Converse County
Totals

1955 -
1956 -

19«3 -
1951 -
1958 -
1957 -
1939 -
1958 -
1924 -
1931 -
1957 -

1955 -

1958 -
1951 -

1958 .

1961 -
1970 -

1958 -
1957 -
1951 -

1962 -


1967
1966

1963
1970
1962
1964
1963
1972
1958 '
1913
1961

I960

1963
1968

1960

1973
1973

1961
1965
1968

1965

Tons of Tailings

1,200,000
800,000

1,555,000
1,900,000
510,000
2,600,000
701,000
2,700,000
350,000
3T.OOO
350,000

90,000

2,600,000
1,500,000

130,000

2,500,000
190,000

123,000
2,200,000
1,700,000

187,000
25,256,000
Ra In Ci

50
670

1,200
1,350
200
610
190
2,130
320
30
70

10

1 520
950

50

1,020
230

20
1,560
1,380

60
13,950
i ii in


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XX X
XX X
X X
X X
X
XX X
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                                                                                                                              VII
  I.  The removal of tailings and other radioactive materials from the  site  to a more  suitable location.

 II.  Stabilize tailings or  complete or improve stabilization to prevent wind and water erosion.

III.  Decontamination of mills!te or Immediate area around "tailings pile.

 IV.  Complete or improve  fencing and posting of oillsites and tailings areas.

  V.  Determine levels of  radioactivity in structures where tailings may have been used in construction and
      determine costs and  measures needed for remedial action where warranted.

 VI.  Conduct ground water surveys in immediate area of millsite and tailings.1

VII.  No phase II study proposed at this time.
                                                            3-8

-------
3.2  The Phase II Studies




     The Phase II studies of 23 sites (Table 3-D, begun in 1975,



consisted of an engineering assessment of existing conditions, and the




identification, evaluation, and cost analysis of alternative remedial



actions for each site (FB 76-78).








     The studies determined ownership, and hydrologic, meteorologic,




topographic, demographic, and socioeconomic characteristics of the




inactive mill sites and alternative sites to which tailings might be




moved.  Radiological surveys were conducted of air, land, and water near




the tailings sites; including estimates of exposures to individuals and




nearby populations, and identification of offsite use of tailings.



Finally, the studies developed alternative remedial action plans for each




site and analyzed their costs.








     The scope of the Phase II study's at each site was guided by the




recommendations of the Phase I studies, as summarized in Table 3-3.  We




will use many results of these studies in this environmental impact




statement, but the reader is referred to the Phase II reports (FB 76-78)




for more detailed, site-specific information.
                                    3-9

-------
3.3  Source Terms




     In assessing the potential health and environmental impact of the




tailings the "source terms," i.e.,  the amounts and concentrations of




radioactivity and nonradiological toxic chemicals in the tailings piles



and in off-site contamination,  are  particularly important.   This section




discusses these sources.








3.3.1  Radioactivity Source Terms




     The estimated area and quantity of tailings at designated inactive




processing sites are shown in Table 3-4.  Approximately 26  million tons




of uranium mill tailings are spread over a total area (pile only) of



1,030 acres.  The total amount of ore processed at uranium  mills from




1948 through 1978 was 156,975,000 tons (DO 79).  The amount of U3oQ




(called "yellowcake") removed from this ore was 328,100 tons.  Chemicals




added in processing operations contribute to the tailings,  so the weight




of tailings solids is about the same as the weight of processed ore.



The tailings at the 22 inactive sites designated under PL 95-604 are




about 16$ of the total weight of tailings.  The remaining tailings are




under license by the NRC or Agreement States and will be subject to



standards EPA will promulgate for active uranium milling sites.








     With few exceptions, the mills at the now-inactive sites used acid




rather then alkaline solvents to disolve uranium out of the ore.  In all




cases, the mills discharged a mixture of solid tailings and liquids to an




impoundment, unusually referred to as a tailings pond or tailings pile.




Part of the liquid was recycled to the mill, but the tailings were




primarily dewatered by deevaporation and seepage.  Seepage of
                                    3-10

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contaminated material was a common occurrence at many sites, the amount




depending on the location and design of the impoundment.  Direct



discharges of liquid to surface streams also occurred during the



operations of some of the now abandoned mills.








     Most of the uranium in the ore is uranium-238, which is radioactive.




Through a long series of intermediate radioactive substances, uranium-238




decays to lead-206, which is stable (Fig. 3-D.  Over the millions of




years since the ore was formed, some of the uranium has decayed and built




up an inventory of its decay products.  Each decay product is being




created at a certain rate, and decays at some rate.  When all products




remain confined to the ore, the production and decay rates for the decay




chain in Figure 3-1 are all the same, and are equal to the decay rate of



uranium-238.  This condition is known as "secular equilibrium."  Those




decay products which precede radon-222 in the chain, including thorium and




radium remain in the ore and will be present in about the same




concentration of radioactivity as the parent uranium.  However, because of




the mobility of the gaseous radon, secular equilibrium is never quite




reached.  The unit of radioactivity is the curie, which is 37 billion



disintegrations per second.








     The thorium content of the liquid portion of tailings at acid process




mills is much higher than in alkaline process liquids.  Thorium is




essentially insoluble in the alkaline cycle, whereas 50$ or more is




dissolved in the acid leach cycle.  The acid and alkaline leach cycles



dissolve about 5% or less of the radium.  Essentially all of the thorium,
                                    3-13

-------
FIGURE 3-1  URANIUM-238 DECAY SERIES
238
92U
4.5 x 109 yr.


a
V
234
90Th
24 days





«








234,,
91 Pa
1.17 min.
tf
Ay


*







234
92U
2.5 x 105yr.


Ar <*,Y
1 r
230
90Th .
8 x 104 yr.
^
226
88Ra
1600yr.
\oL,y
I
222
86Rn
3.8 days
|a,y
218
84Po
3 min.

a
1 F
214
82Pb
27 min.

ATOMIC WT.
ELEMENT
ATOMIC NO.
HALF-LIFE


•





214 210
84Po 84Po
1.6x10-4sec. 138 days
* *
214 PfY 21° P
83Bi a^y 83Bi ^/y
19.7 min. 5 days
^ V ^ T
/ . ... Y .. / j
/Q -. 210 /Q V 206
' P,? 82Pb ' Hf 82Pb
22.3 yr. Stable
                 3-14

-------
radium and other radionuclides other than uranium are discharged to the




tailings pond (SE 75).








     The solid portion of the tailings can be divided into coarse sands




and finer slimes.  Residual uranium in acid leach slimes is about twice




that in the sand fraction.  This is also generally true for radium




content, whereas thorium appears to be about the same in both sands and




slimes.  The uranium radioactivity levels in the tailings are




substantially less than the radium radioactivity levels, due to the



removal of uranium in the milling process.  Thorium-230 levels in tailings




are probably in near equilibrium with radium-226 overall, although the




ratio may vary with location in the pile resulting from variations in the




mill process and any efforts to precipitate radium in the tailings pond.








     Radium decay products in tailings are somewhat lower in activity than




the parent radium.  Radon is a gas which can escape from the pile, but



only about 2Q% or less of the radon produced from the radium leaves the




source particles.  Therefore, about 80$ or more of the radon progeny are




formed within the source particles (CU 73).  The depth of tailings and



cover as well as porosity and moisture content are key factors in



determining how much of the radon leaving the source particles is




ultimately released to the atmosphere.








     Table 3-^ shows the estimated quantity of tailings, area of tailings,




average ore grade, estimated average radium-226 concentration (based on
                                   3-15

-------
average ore grade),  total curies of radium, maximum measured radium




concentrations, and limited information on measured radon-222 release




rates.  For "upgrader," sites where slimes have been removed, the average



concentration is probably lower than that estimated from the average ore



grade.  The Green River, Monument Valley, Slick Rock (UCC), Converse




County were upgrader sites.  The Naturita mill operated as an upgrader



only for a short period before it was shut down.  As shown in Table 3-^>




the maximum radium concentration found in samples ranged from about 1/5 to




25 times the average value estimated from the average ore grade.








3-3.2  Nonradiological Contaminants




     A number of nonradioactive toxic substances from ore or from process




chemicals have been found in the liquid and solid portions of uranium mill




effluents (SE 75).  Information on their concentrations in tailings and



ground water at the inactive sites is given in the Phase II reports




(FB 76-78).  The contaminants present in a mill waste stream vary with ore




source and type of processing.  Examples of the elements and compounds




found in one tailings pile at an inactive alkaline leach uranium mill are



shown in Table 3-5.  The concentrations in the sands and slimes portions



are given, along with the ratio of the concentration in slimes to that in



a "background" soil sample.  Uranium and thorium are radioactive, but are



also included in this table.








     Table 3-6 indicates additional elements and compounds which have been




reported in other tailings piles.
                                    3-16

-------
                            TABLE  3-5

 Elements and Compounds Measured in  an  Inactive Tailings  Pile(a)
Element
or Compound
Uranium
Molybdenum
Selenium
Vanadium
Arsenic
Chlorine
Antimony
Calcium
Cerium
Bromine
Sodium
Iron
Terbium
Cobalt
Aluminum
Barium
Europium
Gallium
Lanthanum
Manganese
Scandium
Zinc
Chromium
Potassium
Thorium
Titanium
Ytterbium
Cesium
Hafnium
Magnesium
Rubidium
Tantalum
Neodymium
Strontium
Tungsten
Concentration in
Tailings Sands
(parts per million)
211
— (b)
31.3
20 4
27
ND(c)
0.69
2830
90
2.5
1080
1060
0.37
2.9
4280
663
0.95
5.5
24
335
2.5
15
10
2350
4.6
1330
1.6
2.4
3.6
4190
82
0.42
41
183
0.49
Concentration in
Tailings Slimes
(parts per million)
380
300
133
2050
79
580
2.2
2670
163
7.6
1970
3550
0.63
9.3
6660
572
1.48
17
44
388
7.0
68
25
2110
8.8
2140
2.9
2.4
4.8
2180
63
0.62
95
ND
ND
Slimes/Background
160
160
100
, 70
18
13
5
5
5
4
4
3
3
2.5
2
2
2
2
2
2
2
2
1
1
1
1
—
1
1
1
1
1
—
—

(FB 76-78)
— indicates no data
ND indicates not detected
                               3-17

-------
                                TABLE 3-6




Additional Elements and Compounds Found in Uranium Mill Tailings(a)
                  Boron




                  Cadmium




                  Copper



                  Gold




                  Lead




                  Mercury
Nickel




Silver




Zirconium




Cyanide



Silicate
    (FB 76-78)
                                  3-18

-------
     To illustrate the site-specific variability of the concentrations of




these substances in tailings compared to the "background" soil at the




sites, Table 3-7 shows the ratios for certain elements at various sites.



Note the difference in the uranium ratios from the two reports on Ambrosia




Lake.  This indicates the variability in tailings assay for different




parts of a pile.








     Contamination of ground water has occurred at some inactive uranium




mill sites, most likely by seepage from the tailings ponds during and




following the period of active operation.








     The primary source of ground water contamination within the first few




decades after mill operation is the tailings pond water discharged while




the pile is active.  Kaufmann, et al^ (KA 76), estimated that 30% of the




water from two active tailings ponds seeped into the ground.  Purtyman,




£t al._, estimated seepage loss from an inactive pile in New Mexico during




its active life as M% (PU 77).  The NRC DGEIS on Uranium Milling uses a




model which assumes a 38$ water loss by seepage (NU 79),  and estimates



movement of seepage through the unsaturated soil zone, formation of the




seepage bulb in the saturated soil zone, and movement of pollutants



down-gradient with the ground water.  For its model mill, which is in an




arid region, the NRC concluded that about 95$ of the possible contamination




was associated with the active phase of the pile and only 5% with the



long-term losses from the inactive pile (NR 79).
                                    3-19

-------
                                   TABLE 3-7

                  Site-Specific Variability of Concentrations
              of Elements  in Tailings Compared to Background Soil
Element in Soil
                      Site
 Ratio in Tailings to
	Background	
Arsenic
Vanadium
Uranium
Selenium
Molybdenum
               Ambrosia Lake,  NM(a)
               Ambrosia Lake,  NM(b)
               Durango, C0(c)
               Lakeview, OR(d)
               Maybell, C0(e)

               Ambrosia Lake,  NM(a)
               Ambrosia Lake,  NM(b)
               Maybell, C0(e)

               Ambrosia Lake,  NM(a)
               Ambrosia Lake,  NM(b)
               Lakeview, OR(d)
               Maybell, C0(e)

               Ambrosia Lake,  NM(a)
               Ambrosia Lake,  NM(b)
               Durango, C0(c)
               Lakeview, OR(<0
               Maybell, C0(e)

               Ambrosia Lake,  NM(a)
               Lakeview, OR(c)
         18
          3
          0.2
         92.3
          7

         71
        326
         52

        160
    210,000
         20
    120,000

        100
     67,500
         20
         10
     12,600

        160
(a)
(b)
(c)
(d)
(e)
DR 78 (Slimes/bkgd)
(FB 76-78) (GJT-13)
(FB 76-78) (GJT-6)
(FB 76-78) (GJT-18)
(FB 76-78) (GJT-11)
                                    3-20

-------
     Tailings piles at inactive mill sites already have lost much of the




water that was present when they were formed.  The water either evaporated,



went underground, or ran out on the surface.  Any future contamination of




water by the pile mainly would result from erosion, precipitation, or




flooding.  The quality of streams and lakes could be degraded by seepage



from a pile, or by tailings which runoff or blow into them.  Table 3-8




indicates inactive and active sites where elevated concentrations of




nonradiological contaminants have been found in ground water near tailings




piles.








3.3-3  Off-Site Contamination




     In 1972, EPA and AEC, using a mobile detector in the vicinity of



tailings sites, located areas with higher than normal gamma radiation.  To



determine the source of the anomalies, teams from EPA and the State health




departments conducted further gamma surveys.  At hundreds of locations,




tailings were found under or within 10 feet of structures (FB 76-78), and




at additional hundreds of locations, more than 10 feet from a structure.




These figures exclude Grand Junction, where there is a separate remedial



action program.  Tailings from some sites have been used off-site




subsequent to the 1972 surveys (Cane Valley, Arizona and Edgemont,



S. Dakota), and in at least one case the gamma surveys were not completed




(Salt Lake City, Utah).  Table 3-9 shows the number of locations near each




designated site where the use of uranium mill tailings has been detected.
                                   3-21

-------
                                 TABLE 3-8

           Elements/Compounds Reported in Elevated Concentrations
             in Ground Water  in the Vicinity of Tailings Piles
        Site

Ambrosia Lake,  NM(a)

Ray Point, TX(b)

Green River, UT(c)

Gunnison, C0(d)


Falls City, TX(e)
Grants Mineral Belt,  NM(f)
     (Active Mills)
Contaminants

Barium, Lead, Vanadium

Arsenic

Arsenic, Chromium, Lead, Selenium

Arsenic, Barium, Chromium, Iron,
Lead, Selenium, Vanadium

Arsenic, Barium, Chromium, Iron,
Lead, Selenium, Radium, Vanadium

Polonium, Selenium, Radium,
Vanadium, Uranium, Ammonia,
Chloride, Nitrate, Sulfate
     (FB 76-78) (GJT-13)
(b)  (FB 76-78) (GJT-20)
     (FB 76-78) (GJT-TO
     (FB 76-78) (GJT-12)
     (FB 76-78) (GJT-16)
     (KA 75)
                                    3-22

-------
                                                                     TABLE 3-9



                                                       Gamma Radiation Anomalies and Causes(a)


Location
Arizona
. Cane Valley (b)
Cameron
Cutter
Tuba City
State Total
Colorado
Cameo
Canon City
Clifton
Collbran
Craig
Debeque
Delta
Dove Creek
Durango
Fruita
Gateway
Glade Park
Grand Junction(c)
Grand Valley
Gunnison
Leadville
Loma
Mack
Mesa
Mesa Lakes
Molina
Naturita
Nucla
Palisade
Plateau City
Rifle
Salida
Slick J?ock
Uravan
Whitewater
State Total
Idaho
Idaho City
Lownan
Salmon
Number of
Anomalies
Detected

19
3
5
17
• 44

3
187
1083
115
86
109
"»3
83
354
1276
17
1
14542
110
47
91
199
90
123
3
43
33
13
939
28
810
64
9
209
' 55
6253

3
11
76
Cause of Anomaly
Radioactive Source Natural
Tailings

15


7
22

1
36
159
4
8
2
1
59
118
58
12
1
5178
10
3
18
10
6
1


10
3
107
1
168
6
3
208

1013


8

or Ore

4
1
5

10


24
31
2
7

3 ••
19
67
48
2

7229
2
9
2
4
2
2


20
6
39

27
2
6

4
7560ld)


•
2
Radioactivity




3
3


99
14

46
1
29
2
67
26


.(d)

28
65
4




1
2
14

1
52


2
453CdJ

2
3
65
Unknown


2

7
9

2
28
876
139
25
106
10
3
102
1144
3'

2135
98
7
6
' 181
82
120
3
43
2
2
779
27
614
4

1
49
4456

1

9
State Total
90
70
                                                                                      10
                                            3-23
                                                                       (con't.)

-------
                                      TABLE 3-9 (Con't)



                           Gamma Radiation Anomalies and  Causes(a)


Location
New Mexico
Bluewater
' Gamerco
Grants
Milan
Shiproek
State Total
Oregon
Lakeview
Kew Pine Creek
State Total
South Dakota
Edgemont
Edgemont
and Dudley(e)
Hot Springs
Provo
State Total
Texas
Campbell ton
Coughran
Falls City
Fashing
Floresville
George West
Karnes City
Kenedy
Panna Maria
Pawnee
Pleasanton
Poth
Three Rivers
Tilden
Whitsett
Number of
Anomalies
Detected

2
5
101
41
9
158

18
U
22

55

84
45
4
188

7
1
5
1
16
10
10
22
3
1
21
15
5
11
1

Cause of
Anomaly

Radioactive Source Natural
Tailings

1

7
5
8
21





43

17

3
63



2



2
1




1


or Ore

1

50
27
1
79

2
1
3

3 ..

16
3
1
23

1


1



1

1
3




Radioactivity


5
25
1

31

10

10

1

51
17

69

6
1
3

14
10
6
13
3

17
14
2
11
1
Unknown



19
8

27.

6
3
9

8


25

33



•

2.

2
7


1
1
2


State Total
129
                                                                        101
15
                                                                      (con't.)
                                               3-24

-------
                                     TABLE  3-9  (Con't)

                         Gamma Radiation Anomalies  and  Causes(a)


Location
Utah
Bland ing
Bluff
Cisco
Crescent Junction
Green River
Magna
Mexican Hat
Mexican Hat
(Old Mill)
Moab
Konticello
Salt Lake City(O
Thompson
State Total
Washington
Creston
Ford
Reardan
Springdale
State Total
Wyoming
Hudson
Jeffery City
Lander
Riverton
Shirley Basin
State Total
Totas
Number of
Anomalies
Detected
—
38
2
2
2
23
. 27
5

14
125
59
225
30
552

3
1
10
2
16

8
28
86
86
9
217
22213

Cause of
Anomaly

Radioactive Source Natural •
Tailings

10



1
1


10
, 15
31
70
26
164








13
4
15
9
41
6518
or Ore

21
1
2
1
14
2
5

3
83
19
15
3
169 '







2
10
9
15

36
7889ld;
Radioactivity

3



1
21


1
6

76

108

3
1
10
2
16

5
3
53
33

94 .
955ld;
Unknown

4
1

1
7.
3



21
9
64
1
111


.




1
• 2
20
23

46
6851
(a)  (Ref. OR 73)
(b)  From EPA report ORP/LV-75-2, August 1975.  Cane Valley was not included in initial
gamma survey program.
(o)  A remedial action program for buildings with tailings has be =n In progress since 1972
under Public Law 92-314.
(d)  'Survey data for Grand Junction,  Colo,  does not distinguish the category "Radioactive
source or ore" from "Natural radioactivity."
(e)  Survey of additional anomalies conducted in 1978.
(f)  Salt Lake City was not completly surveyed.
                                              3-25

-------
              TABLE 3-9



Gamma Radiation Anomalies and Causes(a)


Location
Arizona
Cane Valley (b)
Cameron
Cutter-
Tuba City
State Total
Colorado
Cameo
Canon City
Clifton
Co lib ran
Craig
Debeque
Delta
Dove Creek
Durango
Fruita
Gateway
Glade Park
Grand Junction^0'
Grand Valley
Gunnison
Leadville
Loma
Mack
Mesa
Mesa Lakes
Molina
Naturita
Nucla
Palisade
Plateau City
Rifle
Salida
Slick Rock
Uravan
Whitewater
State Total
Idaho
Idaho City
Lowman
Salmon
State Total

Number of
Anomalies
Detected

19
3
5
17
44

3
187
1083
' 145
86
109
43
83
354
1276
17
1
14542
110
47
91
199
90
123
3
43
33
13 '
939
28
810
64
9
209
55
20,795

3
12
77
92

Cause of Anomaly
Radioactive Source Natural
Tailings

15


7
22

1
36
159
4
8
2
1
59
118
58
12
1
5178
10
3
. 18
10
6
1


10
3
107.
1
168
6
3
208

6191


9
1
10

or Ore

4
1
5

10


24
3*
2
7

3
19
67
48
2

7229(d>
2
9
2
4
2
2


20
6
39

27
2
6

4
7560W



2
2

Radioactivity




3
3


99
14

46
1
29
2
67
26


_(d)

28
65
4




1
2
14

1
52


2
453 V a:

2
3
65
70
(cont'd.)
Unknown


2

7
9

2
28
876
139
-5
106
10
3
102
1144 •
3

2135
98
7
6
181
82
120
3
43
2
2
779
27
614
4

1
49
6591

1

9
10

                 3-23

-------
                                     TABLE 3-9 (Con't)



                           Gamma  Radiation Anomalies  and Causes(a)


Location
New Mexico
Blue water
Gamerco
Grants
Milan
Shiprock
State Total
•Oregon
Lakeview
New Pine Creek
State Total
South Dakota
Edgemont
Edgemont
and Dudley^6)
Hot Springs
Provo
State Total
Texas
Campbell ton
Coughran
Falls City
Fashing
Floresville
George West
Karnes City
Kenedy
Panna Maria
Pawnee
Pleasanton
Poth
Three Rivers
Tilden
Whitsett
Number of
Anomalies
Detected

2
5
101
41
9
158

18
4
22

55
84
45
4
188

7
1
5
1
16
10
10 '
22
3
1
21
15
5
11
1
Cause of Anomaly
Radioactive Source Natural
Tailings

1

7
5
8
21





43
17

3
63



2



2
1 .




1


or Ore

1

50
27
1
79

2
1
3

3
16
3
1
23

1


1



1

1
3




Radioactivity


5
25
1

31

10

10

1
51
17

69

6
1
3

14
10
6
13
3

17
14
2
11
1
Unknown



19
8

27

6
1
J
9

8

25

33





2

2
7


1
1
2


State Total
129
101
15
                                                                  (cont'd.)
                                                3-24

-------
                                        TABLE 3-9 (Con't)

                             Gamma Radiation Anomalies and Causes(a)
Number of •
Anomalies
Location Detected
Utah
Bland ing
Bluff
Cisco
Crescent Junction
Green River
Magna
Mexican Hat
Mexican Hat
(Old Mill)
Moab
Monticello
Salt Lake City(f>
Thompson

38
2
2
2
23
27
5

14
125
59
225
30
Cause of Anomaly
Tailings

10



1
1


10
15
31
70
26
Radioactive Source
or Ore
•
21
1
2
1
14
2
5

3
83
19
15
3
Natural
Radioactivity

3



1
21


1
6 .

76

Unknown

4
1

1
7
3



t1
9
64
1
State Total
552
State Total
                       15
State Total
                      217
164
                41-
                                                        169
108
                                                       16
                                                                                          111
Washington
Creston
Ford
Rear dan
Springdale

3
1
10
2

3
1
10
2
Wyoming
Hudson
Jeffery City
Lander
Riverton
Shirley Basin

8
28
86
86
9


13
' 4
15
9

2
10
9
15


5
3
53
33


1
2
20
23

                                                                                           46
                                    6518
                                 7889^'
                                                    6851
Totals             22,213
    (a)  (Hef.  OR 73)
    (b)  From EPA report ORP/LV-75-2,  August  1975.   Cane  Valley  was  not  included  in  initial
    gamma survey program.
    (o)  A remedial action  program for buildings  with  tailings has been  in  progress  since  1972
    under Public Law 92-314.
    (d)  Survey data for Grand Junction,  Colo,  does  not distinguish  the  category  "Radioactive
    source or ore" from "Natural  radioactivity."
    (e)  Survey of additional  anorealies conducted in 1978.
    (f)  Salt Lake City was not completly surveyed.
                                                  3-25

-------
     EPA began a complementary gamma radiation survey in the spring of

1974 to determine the extent of contamination by wind-eroded and water-

eroded tailings at the inactive uranium mill sites (DO 75).  Gamma

radiation from the ground was measured by adjusting detector readings for

contirbutious from other sources, including direct and scattered radiation

from the tailings pile.  Gamma radiation levels above the normal

background from the ground indicated contamination by tailings.   Contour

lines, corresponding to net (above background) gamma radiation''  levels

of 40 uR/hr, 10 uR/hr, and zero (i.e., background), were plotted on maps

of each site to show the locations of contamination (FB 76-78).

Table 3-10 provides estimates of the areas contaminated at a given gamma

level for the 20 inactive sites surveyed.  The Oregon Department of Human

Resources requested that the Lakeview site not be surveyed because the

pile was stabilized during the summer of 1974.  The Canonsburg,  PA, site

also was not included in the survey.
         roentgen (R) is a unit measuring the electrical charge gamma
rays release in air.  A microroentgen (uR) is one millionth of a
roentgen.  A rad measures the energy absorbed per unit mass;  one rad is
100 ergs absorbed per gram.  Exposing body tissue to 1 uR of gamma
radiation produces a dose of approximately 1  urad.
                                   3-26

-------





















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                          References  for  Chapter  3
(AE 74)   U.S.  Atomic  Energy Commission,  1974,  "Phase  I  Studies  of  Inactive
         Uranium Mill Sites and  Tailings Piles,"  (Summary  and individual
         site  reports).

(BE 75)   Bernhardt, D.E.,  Johns,  F.B.,  and  Kaufmann,  R.F.,  1975, "Radon
         Exhalation from Uranium Mill Tailings Piles, Description  and
         Verification of the Measurement Method,"   U.S.  Environmental
         Protection Agency, Office  of Radiation Programs,  Technical  Note
         ORP/LV-75-7U).

(CU 73)   Culot,  M.V.S.,  Olson, H.G., Schiager,  K.J.,  1973,  "Radon  Progeny
         Control in Buildings,"  Colorado State University.

(DO 75)   Douglas, R.L. and Hans,  J.M.,  Jr.,  August  1975,  "Gamma Radiation
         Surveys at Inactive Uranium Mill Sites," Technical Note
         ORP/LV-75-5.

(DO 79)   U.S.  Department of Energy, January 1,  1979,  "Statistical  Data of
         the Uranium  Industry,"  DOE Grand Junction  Office,  Colorado,
         GTO-100 (79).

(DR 78)   Dreesen, D.R.,  Marple,  M.L., and Kelley, N.E.,  1978 "Contaminant
         Transport, Revegetation, and Trace Element Studies at  Inactive
         Uranium Mill Tailings Piles,"  in Proceedings of the Symposium on
         Uranium Mill Tailings Management,  Colorado State University,  Fort
         Collins, 111-139.

(FB 76-78)   Ford, Bacon, and Davis, Utah, Inc., "Phase  II-Title 1,
            Engineering  Assessment  of Inactive Uranium  Mill Tailings,"
            20 contract  reports  for Department of Energy Contract
            No.  E(05-D-1658, 1976-1978.

(KA 75)   Kaufmann, R.F., Eadie,  G.G., and Russell,  C.R.,  1975,  "Summary of
         Ground Water Quality Impacts of Uranium  Mining and Milling  in the
         Grants Mineral  Belt, New Mexico."   U.S.  Environmental  Protection
         Agency, Office  of Radiation Programs,  Technical Note ORP/LV-75-4.

(OR 73)   Office of Radiation Programs,  March 1973,  "Summary Report of  the
         Radiation Surveys Performed in Selected  Communities, "U.S.
         Environmental Protection Agency.

(SE 75)   Sears,  M.B., et al^, 1975, "Correlation  of Radioactive Waste
         Treatment Costs and the Environmental Impact of Waste  Effluents
         in the Nuclear  Fuel Cycle  for  Use  in  Establishing 'as  Low as
         Practicable' Guides - Milling  of Uranium Ores," Two Volumes,  Oak
         Ridge National  Laboratory  report ORNL-TM-4903.
                                   3-29

-------
4.  HEALTH EFFECTS








4.1  Introduction




     In this chapter we discuss pathways by which radioactive materials in




tailings piles can reach people and the potential consequences to human




health of such exposures.  The possible consequences of nonradioactive




toxic materials are also discussed.








     Uranium mill tailings are unique compared to the wastes from most




other metallic ores because of the amount of radioactivity they contain.




Their primary hazard to health is due to this radioactivity, although




nonradioactive toxic chemicals such as arsenic, lead, selenium, mercury,




sulphates and nitrates may also be present.  The milling of uranium




bearing ores removes about 90 percent of the uranium.  Radionuclides which




accompany uranium and the toxic chemicals in the processed ore are




discarded in the waste stream consisting of solid tailings and liquids.








     Uranium mill tailings emit three kinds of radiation: alpha rays, beta




rays, and gamma rays.  These are ionizing radiations, meaning that they




break up molecules into electrically charged fragments.  In tissue, this




ionization can result in cellular changes that are detrimental to human




health.  At the low levels of radiation encountered in the environment,




any effects of such changes are not immediately detectable.  However,



based on studies of human populations exposed at high doses indicate that




irradiated of people increases their probability of developing cancers.

-------
Moreover, if the gonads are exposed, there is increased risk of detrimental




genetic effects in progeny.








     The increased chance of cancer occurring after exposure to radiation




is only known within broad limits.  It is our practice and that of other




Federal agencies to base risk estimates on studies of persons exposed at



high doses, and to presume that the effects at lower doses will be propor-




tionately less.  This assumption may, in some cases, overestimate or




underestimate the actual risk, but it is the best that can be done at



present (EP 76).








     The major health hazard from uranium mill tailings is alpha radiation



from the short half-life decay products of radon.  Other radioactive




materials in the tailings can also cause harm by direct gamma ray exposure,




by breathing airborne particulates, and by ingesting particulates with food




and water.  Except within a few miles of a tailings pile, those pathways



are minor compared to the potential harm from breathing the short half-life




radionuclides resulting from the decay of radon gas.  The following



discussion concentrates on those materials emitting alpha rays, since they



are more dangerous when deposited within the body than materials emitting



other types of radiations.








     Exposure of internal organs to alpha radiation is not associated only




with uranium mill tailings.  Alpha radiation is emitted by many, if not



most, of the naturally-occurring radioactive materials such as radium,
                                    4-2

-------
uranium, and thorium.  Almost all natural substances contain these elements

in low concentration.  For example,  ordinary soil and rocks average about

one picocurie (pCi)^ of radium per gram, and outdoor air contains a few

tenths of a pCi of radon per liter (UN 77).  The normal diet and breathing

provide entry of these materials into the body with a concurrent potential

for cancer and genetic effects from alpha radiation exposure.  In this

discussion, the effects of exposure to radioactive materials in tailing

piles are compared to those from exposures that occur normally.  This

information is not provided to justify the risk due to tailings on the

basis of other hazards, but rather as a point of reference.
^A picocurie of radioactive material has a decay rate of
 2.22 disintegrations per minute.

-------
4.2  Radon and Its Immediate Decay Products

     For certain radionuclides, the decay of one radioactive atom gives

rise to another radioactive atom, which in turn decays to form a third

radioactive atom, etc.  Such a sequence is known as a radioactive decay

series or decay chain.  The uranium-238 decay series is shown in

Figure 3-1•  Although most of the uranium in ore is removed in the milling

process, its decay products, which have different chemical characteristics,

are part of the mill waste stream.  The most important of these in a

temporal sense is thorium-230, which decays to become radium-226.  Because

the half-life1 of thorium-230 is very long (80,000 years), for all

practical purposes, tailings are a permanent source of radium

contamination.  Since the usual chemical form of radium is not very

soluble in water, it is as controllable as other solid toxic materials

having similar chemical characteristics.  However, the radium-226 decay

product, radon-222, is not completely retained in the tailings pile.

Radon, a nonreactive radioactive gas, diffuses from the pile and becomes

windborne.  The half-life of radon is 3-8 days, so some radon atoms can

travel a considerable distance—thousands of miles—before they decay.




     As shown in Figure 3-1» the radon decay chain has seven principal

members before it ends in nonradioactive lead-206.  The potential health

effects of inhaling short half-life radioactive decay products which
1The half-life is the time it takes for any given quantity of a
radionuclide to decay to half of that quantity.
                                    4-4

-------
immediately follow radon decay are of primary importance.  The relatively



long half-life members of the decay chain (beginning with lead-210, which




has a 19-year half-life) are more likely to be ingested than inhaled and




are less important contributors to the risk from uranium tailings than the




short half-life radon decay products.








     The principal short half-life products of radon-222 are polonium-218,




lead-214, bismuth-214, and polonium-214.  They decay, for the most part,




in less than an hour—the first decay product, polonium-218, having a




half-life of just over three minutes (Figure 3-1).  This is long enough




for most of the charged polonium atoms to become attached to microscopic




dust particles in air.  Inhaled aerosols are quite small, usually less



than a millionth of a meter.  When inhaled, such small particles have a




good chance of being retained on the moist epithelium lining of the




bronchial tubes in the lung.  While most of the inhaled material is




eventually cleared from the bronchi by mucus, this process is not fast




enough to prevent exposure of the bronchial epithelium to alpha rays from



polonium-218 and polonium-214.  The dose delivered by these highly




ionizing charged particles cannot be characterized adequately, because the



location of the irradiated cells that eventually give rise to lung cancer



is not established.  Indeed, there is even some lack of agreement as to




which cells are involved.  Therefore, we estimate lung cancer risk due to




inhaled radon decay products from a person's potential exposure to radon



decay products, rather than from the dose absorbed in lung tissues.
                                    4-5

-------
     Radon decay product exposures are measured in a specialized unit




called the working level (WL), which differs from more common measures of



the concentration of radioactivity in air, such as pCi per liter.




Formally, a WL is any combination of the short half-life radon decay




products described above which emits 130,0000 million electron volts (MeV)




of alpha ray energy in one liter of air.  This is the amount of alpha ray




energy emitted by an equilibrium mixture of 100 pCi per liter each of




polonium-218, lead-2HJ, and polonium-214, but the definition applies to




any combination of short half-life radon decay products.  This is



convenient because the relative amount of each decay product at a location




can change with time depending on ventilation rates and other factors.








     The WL was developed as a measure of radiation exposure to workers in




uranium mines.  The common unit of cumulative exposure is the working



level month (WLM), i.e., occupational exposure to air containing one WL of




radon decay products for 170 hours, a working month.  Continuous exposure




by a member of the general population to one WL for one year can be shown




to be about 27 WLM (EP 28).
                                    4-6

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4.3  Estimates of the Lung Cancer Risk From Inhaling Radon Decay Product




     There is a well-documented history of a very high incidence of lung




cancer mortality among underground miners (EP 78, AR 79).  Although




uranium miners are particularly affected, miners of lead, iron, and zinc




who were exposed to relatively low levels of radon decay products also



show an increased lung mortality that is correlated with their exposure.




Moreover, the type of lung cancer most frequently observed is rather




uncommon in the general population.  For the most part, these miners were




exposed to much higher levels of radon decay products than occur in the



general environment.  Although health studies of underground miners provide




a basis for estimating risks due to radon exposures in nonoccupational




situations, such estimates are far from precise.  Not only are the miners'




exposures somewhat uncertain, but more important, there is considerable




statistical uncertainty in the true number of excess cases because of



small sample sizes, as shown in Figure 4-1.  There are also uncertainties



in extending these results to members of the general population because of




significant demographic differences between the miners and the general



public.  The miners were healthy men above the age of fourteen, many of




whom were frequent cigarette smokers.








     Nevertheless, information obtained on miner populations can be used



to estimate, if not predict, the risks due to radon decay products.  A




full discussion of our analysis of the underground miner data to obtain




risk estimate the risk of lung cancer mortality is given in "Indoor




Radiation Exposure Due to Radium-226 in Florida Phosphate Lands" (EP 78).
                                    4-7

-------
                                       FIGURE 4-1


                                             Ar
   80
   70
ui


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UJ
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   60
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                                             O CZECH-URANIUM

                                             D SWEDEN-LEAD, ZINC (A), IRON (R.J)

                                             A UNITED STATES-URANIUM

                                             f CANADA-URANIUM

                                             I 95% CONFIDENCE LIMITS
                     RO
                          I
                                     I
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               100       200        300        400       500


                         CUMULATIVE WORKING LEVEL MONTHS
                                                                    600
                    700
                   Excess lung cancer in various miner groups as a function of their

              'cumulative exposure. Note the degree of statistical uncertainty in the

               number of lung cancer attributable to radon daughters. After Archer
               (AR 79).
                                          4-8

-------
Depending on the type of analysis made, the miner data yield various




estimates of how many cancers will occur in excess of those normally



expected.  It is noteworthy that the length of time groups of exposed




miners have been studied to ascertain cause of death is much less than




their expected lifetime.  In other words, the epidemiological studies




are still in progress and the total number of excess lung cancer deaths in




these groups will not be known until all of these miners have died.








     There are two ways of viewing the observed frequency of lung cancer



deaths among the exposed miners in order to estimate the lifetime risk




from inhaling radon decay products: (1) relative risk, which is based on




the percent increase in lung cancer deaths per WLM observed in these



miners and (2) absolute risk, which is based on the number of lung cancer




deaths per WLM and the length of time, in person-years, the exposed




population has been studied.








     For relative risk, we conclude that a 3 percent increase in the




number of excess lung cancer deaths per WLM is consistent with data from



the studies of the underground miners and we have used this value in our




estimates of risk to the general population.  However, as noted in EP 78,



there are important demographic differences between adult male miners and



the general population.  The risk may be as low as 1 percent or as high as
                                4-9

-------
5 percent when applied to the general population (EP 78).  For absolute



risk, we use the estimate of 10 lung cancer deaths per W1M for one million



person-years at risk reported by the National Academy of Sciences (NA 76).



Both of these risk coefficients are used in this statement to examine the



potential consequences of lifetime exposure to radon decay products.








     To estimate the number of lung cancer deaths that might be due to



increased levels of radon in the environment, we have used a "life table"



analysis of the additional risk due to radiation exposure (BU 78).  This



analysis takes account of the length of time a person is exposed and the



number of years a person lives, based on the 1970 U.S. population death



rate statistics, to calculate the number of premature lung cancer deaths



that would occur after a lifetime exposure of 100,000 persons.  Because it



is convenient to characterize radon release from inactive piles in terms



of curies released per year, we divide the resulting risk estimate by



70.7 (an average lifetime, in years).  Using the relative risk model, this


                                   -4
gives a risk estimate of a 2.3 x 10   chance of fatal lung cancer over a



lifetime for each year a person is exposed to 0.01 V7L.  This estimate was



made assuming children are no more sensitive than adults.  If childhood



exposure results in three times greater risk than that to adults, the



estimated relative risk would increase by about 50 percent (EP 78).  Using



a similar life table analysis and an absolute risk model, our estimate is


        -4
a 1 x 10   chance of fatal lung cancer over a lifetime for each year of



exposure to 0.01 WL.  Again, equal child and adult sensitivities are



assumed (EP 78).
                                    4-10

-------
     Regardless of the assumptions made concerning child sensitivity or




the risk model used, our best estimate is 1  to 3 lung cancer deaths per



year of exposure for each 100 person working levels of lifetime exposure.



Person-working levels is the collective exposure to the population at




risk, i.e., the number of people times the average radon decay product



concentration (in working levels) to which they are exposed.








     As indicated above, for the U.S. population as a whole, a larger




number of cancers are calculated using relative risk estimates than by




absolute risk estimates, but this is not the case for all regions con-




sidered in this analysis.  The relative risk estimates calculated for




particular inactive sites are based on the lung cancer death rates in the




area where the exposures occur.  Lung cancer death rates vary between



States and are lower than the National average in several of the States




where inactive tailings sites are located so that the absolute risk




estimate exceeds the relative risk estimate at some of the localities




considered in Section 4.4.








     Besides the estimated number of cancer fatalities, radiation risk can




be stated in terms of the number of years of life lost due to cancer



deaths.  In the relative risk model, the age at which lung cancer occurs



is the same as in the general population.  Since lung cancer occurs most



frequently in those over 70 years of age, the years of life lost per fatal



lung cancer, 14.5 years, is less than for many other fatal cancers.  In




the absolute risk model it is assumed that lung cancer fatalities occur
                                    4-11

-------
throughout life, so that on the average 24.6 years of life are lost for




each fatality.  Therefore, even though the number of lung cancer fatalities




estimated using the relative risk model is nearly twice that estimated



with the absolute risk model, the estimated total years of life lost in




exposed populations is nearly the same.








     Throughout this assessment we use recent data on population sizes,




locations, and mortality.  Therefore, the assessments illustrate the




current effects of tailings piles, but do not predict future effects.  For




convenience, we will express results as deaths per one hundred years.




This is simply the estimated annual rate based on current data multiplied




by 100.  If the population sizes and locations, life style, medical




knowledge, and other patterns of living were to remain unchanged, then



these rates of lung cancer death could persist for the indefinite future.




We will not attempt to assess future effects of tailings, which may either




increase or decrease.  It is sufficiently prudent, we believe, to develop




standards assuming estimated risks based on current data could persist



over the indefinite future.
                                    4-12

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4.4  Impact on Local and Regional Population Due to Radon




     Decay Products



     Because the concentration of radon decay products changes rapidly




with distance from a pile, calculating the collective exposure to the




local population requires complex models.  An accurate estimate of the




collective exposure from a particular pile would consider, in addition to



the number of people exposed, the site of each residence and work place,




the length of time a person is at each, and the wind speed and direction,




since these factors determine the level of radon decay products inhaled by




an individual.  Because these data are not available for any of the




inactive sites, more approximate methods have been used to estimate



regional exposure at a sample of 6 of the 22 inactive sites (SW 80).




These six sites were selected on the availability of sufficient data to



allow a quantitative analyses.  Although so limited, the sample does




include all but two of the urban sites.








     U.S. census tract data was used to establish the number and locations




of exposed persons based on their place of residence only.  In urban areas




census tract information is rather precise, but is less so in rural areas




where the census tracts are large.  Further, it was assumed that the wind




pattern was symmetrical around the pile, with a constant speed of 6.5 mph.



The wind speed determines the amount of dilution and, to a lesser extent,



the degree of equilibrium between the emitted radon and its decay products.



The degree of equilibrium is important because the WL for a given concen-



tration of radon increases with time as the decay products accumulate.  In
                                    4-13

-------
this analysis it was assumed that the radon-radon decay product equilibrium




is 70$ inside all structures and in outside air at locations more than 25




miles (40 kilometers) from the pile.  Within 25 miles of the pile 50%



equilibrium in outside air is assumed.  In this analysis, the local




population is defined as all persons residing within about six miles



(10 kilometers of the inactive pile, and the regional population consists




of persons residing more than 6 but less than 50 miles (80 kilometers)




from the pile.  We recognize that these analyses of local and regional




health impact do not take account of population changes that may have




taken place since 19YO.  Future increases in population density at several




of the urban sites are likely, but we have not attempted to incorporate



projected population growth in this study, because the actual place of




residence would be a critical parameter in determining the exposure and




resultant health impact.








     The results of the EPA study of six inactive piles are summarized in




Table 4-1 in terms of excess lung cancer deaths, years of life lost per



cancer fatality and the average number of days of life lost per exposed




person.  The number of estimated lung cancer deaths associated with an



inactive tailings pile is highly variable, depending not only on the size



of the pile but also the population density in its immediate vicinity.  In



contrast to the estimates of national impact, described below in



Section 4.5, the estimated number of fatal cancers based on the absolute




risk model for persons in Utah is greater than that estimated using the



relative risk model.  This is because the annual lung cancer death rates
                                    4-14

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                                 TABLE 4-1

            Estimated Effect on Local and Regional Populations
       Due to Exposure from Radon Decay Products From Tailings Piles


Salt Lake City, Utah                   Local Population — 361,000 persons

                                         Relative Risk    Absolute Risk
                                           Estimates        Estimates

  Number of fatal cancers/100 yr              72               79
  Years of life lost per fatality             15               25
  Average days of life lost
     per exposed person                        0.8              1.4

                                    Regional Population — 494,000 persons

                                         Relative Risk    Absolute Risk
                                           Estimates        Estimates

  Number of fatal cancers/100 yr               4                5
  Years of life lost per fatality             15               25
  Average days of life lost
     per exposed person                        0.03             0.06
Mexican Hat, Utah           No Permanent Local Population — (1970 Census)

                                     Regional Population — 14,100 persons

                                         Relative Risk    Absolute Risk
                                           Estimates        Estimates

  Number of fatal cancers/100 yr               0.05             0.05
  Years of life lost per fatality             15               25
  Average days of life lost
     per exposed person                        0.01             0.02
                                    4-15

-------
                                TABLE 4-1
                          (continued)
            Estimated Effect on Local and Regional Populations
                 Due to Exposure from Radon Decay Products
Grand Junction,  Colorado
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
   Local Population — 39,800 persons
    Relative Risk
      Estimates

         29
         15
Absolute Risk
  Estimates

     18
     25
          2.6              2.9

Regional Population — 30,600 persons
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
    Relative Risk
      Estimates

          0.2
         15

          0.03
Absolute Risk
  Estimates

      0.2
     25

      0.03
Gunnison, Colorado
    Local Population — 5,060 persons
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
    Relative Risk
      Estimates

          3
         15

          2.3
Absolute Risk
  Estimates

      2
     25

      2.5
                                     Regional Population — 17,060 persons
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
    Relative Risk
      Estimates

          0.02
         15

          0.003
Absolute Risk
  Estimates

      0.01
     25

      0.004
                                   4-16

-------
                                TABLE 4-1
                       (continued)
             Estimated Effect on Local and Regional Populations
                 Due  to Exposure from Radon Decay  Products
Rifle, Colorado (newer pile)
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
 Local Population — 2,700 persons
 Relative Risk
   Estimates

       1
      15

       1.5
Absolute Risk
  Estimates

      1
     25

      1.7
                                     Regional Population — 35,900 persons
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
 Relative Risk
   Estimates

       0.03
      15

       0.003
Absolute Risk
  Estimates

      0.02
     25

      0.003
Shiprock, New Mexico
  Number of fatal cancers/100 yr
  Years of life lost per fatality
  Average days of life lost
     per exposed person
Local Population* — 12,200 persons
 Relative Risk
   Estimates

       5
      15
Absolute Risk
  Estimates

      4
     25
                                     Regional Population — 63,600 persons
                                         Relative Risk
                                           Estimates
                  Absolute Risk
                    Estimates
Number of fatal cancers/ 100 yr
Years of life lost per fatality
Average days of life lost
per exposed person
*within 10 miles
.1
15

0.007

.1
25

0.01

                                   4-17

-------
in Utah are comparatively low. The risks listed Table 4-1 are calculated




on the basis of radon emissions from just the inactive tailings pile and




do not include any additional risk that may occur fom the use of tailings




in construction.








     Radon exposures to the local population near the Canonsburg,



Pennsylvania, site differs from those listed in Table 4-1 in that most of



the exposure is received by persons working at the site.  We estimate the




risk to workers at the site and to the local population as 29 or 17 fatal




lung cancers per 100 years, using relative and absolute risk estimates,




respectively.  On the basis of the limited data currently available on the



Canonsburg site, the risks there appear to be comparable to that due to




the inactive piles located in urban areas, c.f. Table 4-1.








     The regional impacts estimated in Table 4-1 are measures of the




collective risk to those persons exposed.  Within this group, the exposure




and resultant risk to individuals differs greatly depending on their



distance from the pile.  Table 4-2 lists the calculated exposure and




estimated individual risks due to lifetime exposure as a function of



distance from a hypothetical inactive pile having a radon emission rate of




10 kilocurie per year.  The assumed wind speed and exposure conditions are



the same as those described above.  Because a specific site is not



considered, only estimates based on the absolute risk model are listed in



Table 4-2.  The estimated absolute risks as a function of distance at
                                    4-18

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                                 TABLE 4-2
                  Individual Risk Due to Lifetime Exposure
                          to Radon Decay Products

                  Radon Release Rate —  10,000 Ci per year
Distance from Pile Edge
	(miles)	

          0.2

          0.4

          1.0

          2.0

          4.0

         10.0

         20.0

         40.0
Exposure
   WL

0.013

0.005

0.001

0.0004

0.00014

0.000022

0.0000041

0.0000016
Chance of Fatal(a)
  Lung Cancer

 9.2 in 1000

 3.5 in 1000

 7.1 in 10000

 2.8 in 10000

 1.0 in 10000

 1.6 in 100,000

 2.9 in 1,000,000

 1.1 in 1,000,000
^'Absolute risk model.
                                   4-19

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specific sites will be proportional to the annual radon emission, listed




in Table 3-3 and Table 3-4.  For example at a site where the emissions are




5 kilocuries per year, the risk to an inidividual residing at a given




distance will be half of that listed in Table 4-2.








     As can be seen in Table 4-2 the risk to individuals varies enormously




depending on how close they live to the pile.  At distances between




1-3 miles from this hypothetical pile the increased radon concentration in




outside air is about equal to that which may occur normally in residential




structures (see below).  Because distance is such an important factor in




determining the exposure, and risk, it is useful to consider specific



sites.








     Several of the inactive mill tailings sites are in urban areas where




a few individuals live and work very near the edge the piles, where the




concentration of radon is high.  Table 4-3 lists the location of homes and




estimated working levels in outside air at five of the urban sites.  Except



for the inactive pile in Salt Lake City, radon emissions from inactive




piles are smaller than the emission rate used as the basis for Table 4-2.




The radon levels at the sites listed in Table 4-3 are based on exposure



information in the Ford, Bacon Davis Engineering Assessments of inactive



piles prepared for the Department of Energy (FB 76-?8), and are not



directly comparable to those listed in Table 4-2.  Estimates of individual



risks for lifetime exposure at sites listed in Table 4-3 are as high as
                                   4-20

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                                 TABLE 1-3

  Estimated Risk to Nearest Residents from Radon Decay Products Inhalation

                    (Lifetime Exposure at  Current Levels)
     Site                                Relative Risk    Absolute Risk
                                           Estimates        Estimates

Salt Lake City, UT ~ (0.05 mile, 0.045 WL)(a)

  Lifetime chance of fatal cancer              0.03               0.03
  Years of life lost per fatality             15                 25


Grand Junction, CO — (0.1 mile,  0.045 WL)(a)

  Lifetime chance of fatal cancer              0.04             0.03
  Years of life lost per fatality             15               25


Durango. CO — (0.1 mile, 0.026 WL)(a)

  Lifetime chance of fatal cancer              0.03             0.02
  Years of life lost per fatality             15               25


Rifle, CO — (0.5 mile,  0.007 WL)(a)

  Lifetime chance of fatal cancer              0.008            0.005
  Years of life lost per fatality             15               25


Gunnison, CO ~ (0.5 mile, 0.008 WL)(a)

  Lifetime chance of fatal cancer              0.009            0.006
  Years of life lost per fatality             15               25
    The distance and radon concentration including background for the
    nearest resident to the pile (FB 76-78).
                                   4-21

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about a one in twenty five chance of death due to lung cancer.  As we show




below, this is considerably greater than the normally expected risk due to




residential radon.








     Table 4-4 is an estimate of the risks from the naturally-occurring



radon decay products found in homes that are not associated with mill




tailings or other identified radon sources.  National data on radon decay




products in homes is very scanty but does show a wide variation between



individual houses.  The estimates in Table 4-4 assume that the average




concentration is 0.004 WL in homes that are occupied 75 percent of the




time.  The assumed average radon decay product level is based on some



recent data on 21 houses in New York and New Jersey (GE 79), which is




consistent with data obtained in other countries (UN 77).  For comparison,




the risks estimated in Table 4-4 are about 10 percent of the expected




lifetime risk of lung cancer death from all causes (0.029) in a stationary




population having 1970 U.S. mortality rates.
                                    4-22

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                                 TABLE 4-4

                        Risk Due to Background Radon

                         in Residential Structures


                                                               fa)
                                                 Estimated Riskv
                                            Relative        Absolute

Lifetime chance of fatal lung cancer          0.004           0.002

Years of life lost per fatality              15              25

Average days of life lost
   per exposed person                        23              18
(^Calculated on the basis of 0.004 WL, 75$ occupancy,  and 1970 U.S.
    mortality rates (EP 78).
                                   4-23

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4.5  Risks to the Continental U.S. Population Due to Radon Emission from




     Inactive Piles








     Radon emissions from tailings piles have a potential for health impact




beyond the 50-mile region considered in Section 4.4.  We estimate this




exposure to the U.S. population using two different models for atmospheric




transport.  The simplest, which treats radon diffusion on the basis of




gross meteorology, yields an annual collective exposure of 0.65 person-




working level for each 1000 curies of radon emitted per year to persons




living more than 50 miles (80 kilometers) from an inactive pile (SW 80).  A




more detailed meteorological model developed for EPA by the National



Oceanic




and Atmospheric Administration (NOAA) has been used by the Nuclear Regula-




tory Commission (NR 79) to calculate the concentration of radon in air due




to emissions from four release sites in the western U.S.  Assuming, that a




radon concentration of 100 pCi per liter corresponds to about 0.7 WL, the




average national collective exposure from the four sites considered in the




NRC study range from 0.42 to 0.76 person-working level per 1000 curies




release per year, with an average of 0.56.  This is in reasonable




agreement with our earlier but less exact calculations, and is adopted



here.  This collective exposure does not include those persons living



within 50 miles of a pile.








     Both the EPA and NOAA/NRC assessments are for a continental U.S.




population of 200 million persons based on 1970 U.S. census data.  A



similar geographical distribution of people and a projected U.S.
                                    4-24

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continental population of 220 million persons in 1980 would increase the




collective exposure by about 1056.








     Estimates of lung cancer deaths among persons residing more than 50



miles from inactive tailings piles are listed in Table 4-5 for 21 of the




22 inactive tailings piles.  The radon emissions, on which the risk




estimates in Table 4-5 are based, are calculated from the size of the pile,




the amount of radium per gram of material assuming a radon-222 emission



rate of 1 pCi/sec for each square meter of area and each pCi of radium-226




per gram of tailings (SW 80).  Although various calculated emissions from




tailings piles agree within about 20 percent, complete field measurements



are not available and actual emissions could be considerably different.








     The total effect to persons residing more than 50 miles from the 21




piles at the 19 locations listed in Table 4-5 is summarized in Table 4-6,




which lists a number of different measures of health risk.  It is important



to recognize that these risks are the total for an exposed population of




200 million persons.  On the average, an individual's annual risk from the



model pile is 20 billion times smaller.
                                   4-25

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                                 TABLE  4-5
            Contribution  of Inactive  Uranium Tailing  Piles  to  the
               National Health  Risk from  Radon  Decay  Products
    Inactive Site
Salt Lake City, Utah
Mexican Hat, Utah
Green River, Utah

Grand Junction, Colorado
Gunnison, Colorado
Durango, Colorado
Maybell, Colorado
Naturita, Colorado
Rifle, Colorado(c)
Slick Rock, Colorado(c)

Converse, Wyoming
Riverton, Wyoming

Monument Valley, Arizona
Tuba City, Arizona

Ambrosia Lake, New Mexico
Shiprock, New Mexico

Falls City, Texas

Lowman, Idaho

Lakeview, Oregon
  Annual Risk of Fatal Cancer^
Relative Risk      Absolute Risk
      (fatalities per year)
0.15
0.065
0.012
0.072
0.023
0.024
0.039
0.034
0.055
0.031
0.0031
0.069
0.0062
0.035
0.11
0.042
0.11
0.0046
0.023
0.068
0.028
0.0054
0.031
0.010
0.011
0.017
0.015
0.025
.014
0.0014
0.031
0.0027
0.016
0.05
0.019
.05
.002
.01
        not include effects within 50 miles of the site.
         of life lost and other measures of risk are discussed in
    summary Table 4-6.

    WO inactive piles.
                                    4-26

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                                 TABLE 4-6



                                                    (a)
                       Summary Table—Inactive Piles




     Estimated National Risk of Fatal Lung Cancer from Radon Emissions



                                                    Estimated Risk

   Inactive Sites                             Relative          Absolute



Fatal cancers per 100 years                     90                40



Increased chance of lung cancer death        0.3/1,000,000    0.1/1,000,000



Years of life lost per fatality                 15                25



Average days of life lost

   per exposed person                            0.0017             0.0013
     Canonsburg, PA, site not included.



     Does not include people living within 50 miles of the site.
                                   4-27

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4.6  Regional and National Effect Due to Long Half-Life Radioactive




     Materials



     Windblown partioulates and the long half-life decay products of radon




(beginning with lead-210) are also potential hazards (see Figure 3-D.  The




consequences of eating and breathing these long half-life decay products




cannot be established without site-specific information, including, for



example, sources of food.  The only detailed study is that provided for a




model active site in the NRC Draft GEIS on Uranium Milling (NR 79).




However, as explained below, the results of the NRC analysis are not




entirely applicable to many of the inactive sites.  They are used here only




to identify important routes of exposure and their significance compared to




short half-life decay products of radon, not as truly quantitative




estimates of the risk from tailings at specific inactive sites.








     The NRC model uranium mill and tailings pile is located in a sparsely




populated agricultural area (cattle ranches).  The population in this




region produces all the food they use.  While this scenario maximizes the



dose due to food, it is not appropriate for many of the inactive sites.




For tailings located near urban areas, where the number of persons living




close to the tailings pile is large, the likelihood of complete dependence




on locally supplied food is considerably less.  Nevertheless, it is useful



to consider the various exposure pathways and risks for exposure patterns



considered in the NRC analysis.
                                    4-28

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     The five sources of exposure in the NEC analysis are shown in

Table 4-7.  Inhaling of short half-life radon decay products,  the most

important health risk, is more than ten times greater than the next

highest, that due to windblown tailings taken in from eating vegetables and

meat.^  Lead-210 and polonium-210, formed in air following radon decay,

are also a source of exposure, when they are deposited on food or

inhaled.  According to the NEC analysis, each of these pathways contributes

a risk which is about 1 percent of the risk due to inhaling short half-life

radon decay products.  Even when they are combined, all the risk due to

the long half-life radionuclides is much less important than the risk due

to inhaling of the short half-life radon decay products.  Persons residing

more than 50 miles from an inactive pile would not be as heavily exposed

and their risk would be considerably less than that indicated in Table 4-7.
1The NEC analysis for the ingestion pathway is quite conservative
 because of the retention assumed for deposited materials (50$), and the
 transfer of radium from fodder to meat (3x10-3) are both at least a
 factor of 5 larger than is usually assumed (EP 78a, MC 79).
                                    4-29

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                                 TABLE 4-7

                Regional Impact from Uranium Mill Tailings

                    (NRC-GEIS Model Pile and Population)
                    Population at Risk—57,300 persons
                                              Number of Cancer
                                               Deaths Per Year
Inhaled radon decay products                     6 x 10-2(a)

Ingestion of windblown tailings                  4 x 10-3(b)(c)

Inhaled lead-210/polonium-210                    6 x 10-4(b)

Ingested lead-210/polonium-210                   6 x lO-2*^)

Inhaled resuspended tailings                     0.6 x 10-Mb)
(a; gp£ reiative risk estimate based on 2.4 person WL/yr.
(b; prom the computed data for individual radionuclides used to produce
     the summary tables in the NRC-GEIS (NR 79).
    Particles containing U-238, U-234,  Th-234,  Th-230,  Ra-226,  Pb-210,
     Bi-210; c.f. Fig. 3-1
                                   4-30

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4.7  Impact from Gamma-Ray Exposures




     Many of the radioactive materials in tailings piles are a source of




high energy photons, called gamma rays.  Unlike alpha rays, which must be



lodged within the body before becoming a hazard, gamma rays can penetrate



both air and tissue for considerable distances.  Near the edges of a pile




the exposure from gamma-rays can be many times larger than the ambient




gamma ray background in uncontaminated areas.  However, the concentration




of gamma radiation due to the pile decreases rapidly with distance, so




that it is not measurable above the normal background at more than a few




tenths of a mile from most of the inactive tailings piles.








     Individual gamma ray exposures depend on how close to the edge of a




pile people live or work.  The collective gamma ray dose depends on both




the number of people exposed and their average dose.  In a few cases indi-




vidual doses can be characterized adequately on the basis of available




data, but, in general, this cannot be done in the absence of precise



information on where they live and work and the amount of shielding




provided by structures, etc.  Table 4-8 summarizes outdoor gamma ray




exposures in the vicinity of some western inactive piles and at Canonsburg,



Pennsylvania.  In several cases, even the nearest residents are far enough



from the pile that they receive essentially no excess gamma radiation.  At



others, a few residents are located close enough to perhaps double the



dose from gamma radiation that would occur without the pile.  In a few




cases, the dose to the nearest resident may be several times normal



background levels.
                                    4-31

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     In these localities, "normal" background due to penetrating radiation




is about 100 mR per year (FB 76-?8).  This radiation exposes the total




body, so that all organs are at risk.  The estimated frequency of fatal



cancer and serious genetic effects due to a lifetime exposure of 100 mR




per year is listed in Tables 4-9 and 4-10.  Persons who live or work near



tailings piles will incur risks from long term exposures which exceed




those listed in the tables in proportion to the amount that their annual




dose rate exceeds 100 mR per year.  Although current information does not




allow calculation of the collective gamma ray dose and risk to all persons




living or working near the inactive piles, the total impact is small




because of the limited area having a measurable increase above ambient



levels.
                                    4-32

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     Site

Salt Lake City, UT
Green River, UT

Grand Junction, CO
Durango, CO
Gunnison, CO
Rifle, CO

Lowman, IL

Ambrosia Lake, NM

Spook, WY

Canonsburg, PA
                                   TABLE  4-8

                         Increased Gamma Ray Dose Rates

                         Due to Inactive Tailings Piles(&)
Location of Nearest Resident
  Distance from Pile Edge
          (miles)
Annual Gamma Ray(b)
     Exposure
      (mR/yr)
0.05
0.15
0.1
0.1
0.5
0.25
1.0
1.5
1.5
0.04
465
— (c)
580
200-300
__(c)
— (c)
_.(c)
— (c)
— (c)
150
(^Ambient gamma ray background at each site has been subtracted.

'^'Measured in air (Roentgens).  At these energies 1 mR  1 mrad  1 mrem.

'c'No detectable increase above background.
                                    4-33

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                                 TABLE 4-9

              Estimated Lifetime Risk of Fatal Cancer Due to

                 Total Body Gamma Ray Exposure at 100 mR/y


                                                Estimated Risk(a)
Lifetime chance of fatal cancer

Years of life lost per fatality(b)

Average days of life lost
     per exposed person
Relative

  0.005

 14


 24
Absolute

  0.0008

 23
(a)
   Lifetime risk plateau.
^a'Based on a normal life span of 70.7 years.
                                   4-34

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                                TABLE 4-10

              Estimated Risk of Serious  Genetic Abnormalities

                       Gonadal Dose TOO mR per year
Risk per 100 live births
  First
Generation

0.004 - .06
All Succeeding
 Generations

 .014 - 0.5
Currently observed in U.S.A..
                                   4-35

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4.8  Hazard from Water Contamination








4.8.1  Introduction




     In Chapter 3 we discussed the toxic substances that have been found




in uranium mill tailings or in contaminated ground water near uranium



milling sites.  Although there is some potential health effect of non-




radioactive toxic substances in windblown tailings, the most significant




pathway for evaluating their potential effects is through water.








     The potential effects of nonradioactive toxic substances in tailings




piles must be evaluated by different methods than those we used for radio-




activity.  All ionizing radiation can produce cancer with a probability




that increases with the dose; this is the basis for the radiation risk




estimates.  However, we treat nonradioactive toxic materials as substances




for which the kind of effect varies with the material and the severity




(not its probability of occurring) increases with the dose.  Moreover,




because the body can detoxify some materials or repair the effects of




small doses, there are often threshold dose levels below which no toxic




effects occur.  For radiation effects, we have assumed there is no




completely safe dose.








     Because of these differences, we can not make a numerical risk



assessment for the nonradioactive toxic substances.  However, we can



describe their hazard as components of uranium mill tailings qualitatively




in terms of their likelihood of reaching people (or animals, or
                                    4-36

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agricultural products), the concentrations at which they may be harmful,




and their toxic effects.








4.8.2  Movement of Toxic Chemicals from Tailings



     Tailings can contaminate surface water and ground water.  Surface



water contamination may result from wind erosion, floods, tailings slides




into adjacent streams, or from seepage through the pile or runoff of




rainwater.  Ground water contamination can occur only through seepage into




an underlying aquifer.  Since people may draw water from a single source




at many different places, movement of the contamination is an important




element in assessing the extent to which people may be exposed to it.  In




the following, we discuss contaminant movement in the ground, since




movement through lakes and streams is familiar.








     Available information is not sufficient to estimate the probability




that toxic materials from tailings will move through water and expose



people to them.  However, as we noted in Chapter 3, migration of these




substances in ground water near tailings piles has been observed.  While




the specific substances we would expect to enter and be carried through




ground water will vary among the sites, chemical and hydrological



considerations can identify those that are generally most likely to move.








     Although some organic compounds are present in tailings from acid




leach mills, e.g., amines, kerosene and higher alcohols, we associate the



main long-term ground water hazard with inorganic toxic elements or
                                    4-37

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compounds and with radioisotopes dissolved in the water.  Movement of



contaminants to ground water depends on a combination of complex chemical




and physical properties of the underground environment, and on climate




conditions such as precipitation and evaporation.  Chemical and physical




processes in the subsoil remove part of some contaminants from water




passing through it.  However, other contaminants such as selenium, arsenic,



and molybdenum, can occur in forms which are not removed.








     Studies of leaching at tailings piles (DR 78) and leachates from




municipal land fills (EP 78b) are useful in determining which substances




generally will be relatively mobile or immobile, and which will have a




mobility which varies with local conditions (EN 78c).  Studies of pollutant




migration into ground water near tailings piles are limited, but tend to




confirm estimates using other methods of which elements will be most mobile



(FB 76-78, KA 76, DA 77).  However, there has been no systematic study to




establish the magnitude of ground water contamination for either active or




inactive piles.








     Based on available information, chromium, mercury, nickel, arsenic,



beryllium, cadmium, selenium, vanadium, zinc and uranium have a high



probability of being mobile.  Lead, radium, and polonium are not predicted



as being mobile, but they appear to be in some cases.  There are no data



to suggest or confirm mobilities near tailings piles for the other



elements, but conservative assumptions should be used for compounds which



are generally mobile, such as nitrate, chloride, and sulfate.  Certain
                                    4-38

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anions and organic complexes of trace metals may also be relatively



mobile, although field data from tailings pile studies to confirm this are




extremely limited.  However, if appreciable seepage of those known to have



high mobility is prevented or reduced, then those for which no data are



available should also be controlled.








     Some mixing generally will occur when contaminated water from mill




tailings reaches ground water.  Except in very coarse or cracked media,



contaminants reaching ground water will likely be reduced in concentration




along the flow path by dispersion, sorption, and ion exchange.  Ground




water can move slower than a few feet per year, and only in coarse or




cracked materials does the speed exceed one mile per year.  The low




spreading and flow rates mean that pollution entering ground water may not



affect the quality of nearby water supply wells for decades.  However,




once polluted, the quality of such water supplies can not be quickly




restored by eliminating the source.  Natural improvement in water quality




throughout the affected area may take longer than the period of initial




contamination.








     The concentration of contaminants where ground water may be used




depends on the rate at which they seep into the aquifer and the hydrologic



and chemical properties of the aquifer.  The level of exposure to the




users depends on these factors and on the amount consumed.  This in turn




depends on the palatability and quality of the water, the purposes for



which it is used, and the number of users.  Such data as is available
                                    4-39

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indicates that tailings have contaminated some private wells in the




Grant's Mineral Belt in New Mexico (KA 76) with toxic substances whose




concentrations greatly exceed The National Interim Primary Drinking Water




Regulations which apply for public drinking water supplies.








4.8.3  Toxicity of Major Toxic Substances Found in Tailings




     While there is little data for estimating the probability or the




level of exposure to contaminated water, there is reasonably good infor-




mation on the toxic effects.  For example, no acute toxic effects, i.e.,




death in minutes or hours, could occur except by drinking tailings pond




liquids.  Also, it is unlikely that severe sickness or death occurring in




days to weeks would result from using contaminated ground water, though it




is possible.








     Although acute toxicity may not be a problem, chronic toxicity from




substances in the tailings pile could occur.  Conditions and processes




specific to each tailings pile site determine the substances carried in



ground water and the levels of exposure.  Chronic toxicity results from




continuous consumption of contaminants at rather low concentrations.




Toxic substances may accumulate slowly in tissues and cause symptoms only




after some minimum amount has accumulated.  Symptoms of chronic toxicity



develop slowly, typically over months or years.

-------
     The following is a short discussion of the toxicology of some specific

elements or ions which are important in considering water contamination

control for uranium mill tailings piles.



4.8.3.1  Arsenic

     Arsenic is a metal not known to be essential to human nutrition.  It

is widely distributed in nature and has been used extensively in medical

and agricultural applications.  The pentavalent form is less toxic than

the trivalent  (23 milligrams of arsenic taken as arsenic trioxide has

been fatal (JO 63)), but usually more teratogenic1 (VE 78).




     Chronic poisoning produces skin abnormalities, proteinuria, anemia,

and liver swelling.  Some cardiac and nervous symptoms have been

associated in Japan with drinking well water containing 1 to 3 parts per

million of arsenic (TE 60).  Epidemiologic studies of chronic arsenic

poisoning in Antofagasta, Chile found a high incidence of skin and

cardiovascular abnormalities, of chronic coryza and abdominal pain, and

some chronic diarrhea in children drinking water containing about 600-800

parts per billion of arsenic (NA 77).  The incidence of skin lesions

decreased about a factor of 16 when the arsenic content of the water was

decreased to 80 parts per billion (NA 77), but the effects did not

disappear completely.
^eratogenicity is the capability to cause abnormal fetal
 development.


                                    4-41

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     Chronic consumption of arsenic has also been associated with increased



incidence in lung cancer (VE 78) and skin cancer (VE 78, NA 77, GO 77).








4.8.3-2  Barium




     Barium is a metal not known to be essential in human nutrition.  It




is widely distributed in nature and used in industry, medicine, and



agriculture.  Consumption of 550-600 milligrams of barium as barium




chloride has been reported to be fatal (SO 57).








     Ingested barium causes abnormal muscle stimulation due to induced




release of catacholamines from the adrenal medulla.  There is, however, no



evidence of chronic toxicity from long-term consumption of barium in people




or animals (NA 77, UN 77a).








4.8.3.3  Cadmium




     Cadmium is a metal distributed in the environment in trace quantities




except in some zinc, copper and other ores.  It is not essential to human




nutrition, but is used in industry.  Acute fatal poisoning with cadmium is



difficult because cadmium salts cause vomiting when consumed.  Acute



poisoning from consuming food or drink contaminated with cadmium occurs in



15 to 30 minutes after 15-30 milligrams of cadmium has been ingested




(EN 79).  Symptoms include continuous vomiting, salivation, choking



sensations, abdominal pain and diarrhea.  Acute toxicity symptoms were




also reported in school children eating popsicles containing 13-15



milligrams of cadmium per liter (EN 76).
                                    4-42

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     Absorbed cadmium is toxic to all organs in the body, damaging cells




and enzyme systems.  It is held tightly by the body and accumulates during



the lifetime.  Chronic toxicity has been reported in Japan where people




consumed about 0.6 milligrams of cadmium per day (EN 76).  The toxicity



called "Itai-itai" disease resulted in damage to bones and kidneys.



However, symptoms were seen mostly in older women who had a very poor diet,




low in protein and calcium (UN 77a, NA 77).  Since cadmium toxicity is



moderated by calcium, zinc, copper and maganese (UN 77a) and selenium,



iron, vitamin C, and protein (GO 77), the diet is an important factor in




chronic cadmium toxicity.








     The earliest symptom of chronic cadmium toxicity is kidney damage




evidenced by an increase of protein in the urine.  This is associated with




a cadmium level in the kidney cortex of 200 to 300 micrograms per gram of




wet weight (EN 76, EN 79).  This 200 microgram level could be reached




after 50 years of consuming about 350 micrograms of cadmium per day




(EN 76).  However, consumption of 60 micrograms of cadmium a day has been




estimated to cause kidney damage in 1$ of the exposed group (EN 79).




Smoking influences the cadmium intake since one pack of cigarettes per day




is equivalent to consumption of 25 micrograms of cadmium a day (EN 79).








     Cadmium has caused reproductive disturbances and teratogenesis in



experimental animals when fed at high levels (VE 78, UN 77a, EN 79,




NA 76).  It has also been implicated in human hypertension, cardiac
                                    4-43

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problems, and in prostatic carcinogenesis (UN 77a, EN 79, GO 77,  NA 76),




but the connection has not been definitely established.








U.S.3.4  Chromium



     Chromium is a metal that is essential in human nutrition, involved in




glucose and lipid metabolism and protein synthesis (UN 77a).  The element




is widely distributed in nature and has many industrial applications.  Oral




toxicity is low, and humans can tolerate 500 milligrams chromic sesquioxide




daily (VE 78).  Hexavalent chromium is more toxic than trivalent (UN 77a,




VE 78).  The principle damage in acute poisoning is tubular necrosis in




the kidney.  Although large enough doses of hexavalent chromium can cause



hemorrhage of the gastrointestinal tract, lifetime exposure of laboratory




animals to chromium at less than 5 parts per million in drinking water




caused no reported effects (NA 77, UN 77a).








     There is no information on the effects of chronic consumption in




humans.








4.8.3.5  Cyanide




     Cyanide is a compound composed of carbon and nitrogen existing as the



radical (CN) or the ion (CN)~.  It is not essential in human nutrition.



It is used or formed in many industrial processes and used in agriculture.








     Consumption of 50 to 200 milligrams of cyanide or its salts causes




death in 50% of those exposed (GO 76).  Death usually occurs within one

-------
hour.  Cyanide affects the essential enzyme oytochrome C oxidase which is




required for survival of all cells using oxygen, particularly those in the




brain and heart.








     However, there is no chronic or cumulative toxicity, since the body




can convert doses of 10 milligrams or less to the much less toxic




thiocyanate ion and excrete it (EN 76).








4.8.3.6  Iron




     Iron is a metal essential for human nutrition, involved in oxygen




transport and enzyme systems.  The element is widely distributed in nature



and has medical, agricultural and industrial applications. Ingestion of 15




to 590 milligrams of iron per kilogram of body weight as ferrous sulfate



has been fatal (VE 78); however,  intakes of 25 to 75 milligrams per day




have been cited as safe (UN 77a).  Toxic doses of iron can cause liver and




gastrointestinal tract damage, hypotension, prostration, and peripheral



cardiac failure (VE 78).








     There are no reports on chronic toxicity of ingested iron in animals




or humans outside of Africa (NA 77).








4.8.3.7  Lead




     Lead is a metal widely distributed in nature and used extensively in




industry and agriculture, but it is not essential in human nutrition.  The



amount of lead absorbed before symptoms of toxicity are seen is rarely
                                    4-45

-------
known; however,  one man ingested 3«2 milligrams per day for 2 years before




symptoms occurred (NA 72).








     Lead toxicity is usually related to blood levels of lead:




330 micrograms per 100 grams of blood has been associated with acute brain



pathology and death in children (NA 72).  Levels of 80 micrograms per 100




grams of blood and greater have been associated with brain, nervous system




and kidney pathology, severe colic, seizures,  paralysis, blindness and



ataxia in children (NA 72, GO 77,  NA 77, UN 77a).  Subclinical or hard to




establish effects on the central nervous system, the red blood cells, the




kidneys and enzymes may occur at levels of 40 to 80 micrograms of lead per




100 grams of blood (GO 78).  In women and children some changes in red




cells can be detected at 25-30 micrograms per 100 grams of blood (NA 77).








     Consumption of water containing 100 micrograms of lead per liter




results in blood lead levels of 25 to 40 ug per 100 grams of blood,




(UN 77a, NA 77).  Such exposure could lead to some clinical lead poisoning,




particularly in children (NA 77).








4.8.3.8  Mercury




     Mercury is a metal not essential to human nutrition.  It is



distributed in nature as a trace element except in some metal ores, and




has many industrial applications.   Consumption of 158 milligrams of



mercury as mercuric iodide has been reported to be fatal (VE 78).  Non-



fatal doses of mercury salts cause local irritation, coagulation, and
                                    4-46

-------
necrosis of tissue, kidney damage,  colitis,  hallucinations,  metallic taste




in the mouth, etc.








     The symptoms of chronic mercury poisoning,  as for lead, develop



slowly.  Many of the symptoms relate to the  nervous system,  e.g., insomnia,




anxiety, mental disturbances, ataxia, impaired walking, speech, hearing,




vision, chewing; others are damage to kidneys, blood cells,  gastrointes-



tinal tract and enzyme systems (NA 77, VE 78).  Studies of Minamata




disease (methyl mercury poisoning) suggest that consumption of 1 mg of




mercury per day as methyl mercury over a period of several weeks will be




fatal (VE 78); consumption of 0.3 mg per day will cause clinical symptoms




of mercury poisoning (UN 77a, NA 77).  About 10 times as much methyl




mercury would be absorbed as inorganic mercury (GO 77).








     Mercury passes through the placenta and has caused cases of Minamata




disease by fetal exposure (NA 77), and may cause birth defects (VE 78,




UN 77a).








4.8.3.9  Molybdenum




     Molybdenum is a metal essential in trace quantities for human



nutrition.  It is present in nature in trace quantities, except in some



ores.  It has been widely used in industry.   There are no data for acute



toxicity of molybdenum in humans following ingestion, but the animal data



(VE 78) shows that it must be in the hundreds of milligrams per kilogram




of body weight.

-------
     Chronic toxicity has been seen in persons who have consumed 10 to 15




milligrams of molybdenum per day (CH 79).  Clinical signs of the toxicity




were a high incidence of a gout-like disease and increased urinary




excretion of copper and uric acid.   Increased urinary copper excretion has




been observed in persons consuming 0.5 to 1.5 milligrams of molybdenum per




day, and in persons consuming water containing 0.15 to 0.20 milligrams of




molybdenum per liter, but not in persons who consumed water containing




0 to 0.05 milligrams of molybdenum per liter (CH 79).  The significance of




the increased copper excretion is not known.








4.8.3.10  Nitrate




     Nitrate, a salt of nitric acid, is the stable form of combined




nitrogen in oxygenated water, and all nitrogenous materials in natural




waters tend to be converted to nitrate (NA 77).  The fatal dose has been




estimated as 120 to 600 milligrams of nitrate (27 to 136 milligrams of




nitrate-nitrogen) per kilogram of body weight (BU 61).  Burden estimated




the maximum permissible dose of nitrate-nitrogen as 12 milligrams in a



3 kilogram infant and 240 milligrams in a 60 kilogram adult (BU 61).  The




mechanism of action is apparently conversion of nitrate to nitrite in the




gastrointestinal tract, and the absorbed nitrite is what causes the




toxicity (NA 72a, NA 77).








     Chronic toxicity is usually observed in children.  Symptoms of




toxicity have been reported in children consuming water with 11 milligrams
                                    4-48

-------
of nitrate-nitrogen per liter, or more,  but not in those consuming




9 milligrams per liter or less (NA 72a,  NA 77).








     Nitrates can be reduced to nitrites and combined with secondary



amines or amides to form N-nitroso compounds, which are considered to be




carcinogens (NA 72a, NA 77).








4.8.3.11  Radium




     Radium is a metal widely distributed in the environment in trace




quantitities except in some ores.  It is not essential in human




nutrition.  In the past it was widely used in industry and medicine.



There are no reliable data on acute radium toxicity in man (SI 45) and




chemical toxicity, if any, is expected to be masked by radiation damage



(VE 78).








     Chronic toxicity of radium is expected to be carcinogenesis especially




in bone.  Radium isotopes are expected to have roughly the same chronic




toxicity per unit of activity (picocurie) consumed, but not per unit of




weight (microgram) consumed (IN 79).  A possible exception to this is




radium-227, which is 10^ to 1CT times less toxic than other radium




isotopes (IN 79).








     Consumption of 1 picocurie of radium per liter entails a risk of




developing cancer of about 2 x 10~? (2 in 10 million) per year (EN 76).
                                    4-49

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4.8.3.12  Selenium



     Selenium is a metal widely,  but unevenly,  distributed in nature.   It




is essential in human nutrition in trace amounts (NA 77).   It is used




industrially and in medicine.








     Three-months exposure to water containing 9 milligrams per liter  of




selenium caused development of symptoms of selenium toxicity:  listless-




ness, loss of hair, loss of mental alertness (EN 76).  Other symptoms  of




selenium toxicity include: garlic odor on breath, depression, dermatitis,




nervousness, gastrointestinal disturbance and discoloration of skin




(EN 76, NA 77).  Consumption of 1 milligram per kilogram of body weight




per day may cause symptoms of chronic selenium poisoning (GO 77).  Some




symptoms of chronic poisoning:  bad teeth, gastrointestinal disturbances




and skin discoloration have been associated with consumption of 0.01 to




0.1 milligram of selenium per kilogram of body weight per day (EN 76).








     Selenium has also been suggested to cause increased teratogenesis and




dental caries, but there are little data on these questions (VE 78).








4.8.3.13  Silver




     Silver is a metal distributed in trace levels in the environment



except in some ores.  It is not essential in human nutrition.  It is



widely used in industry, and is used in medicine and art.   Data on acute




toxicity in people are sparse, but consumption of 140 milligrams of silver



nitrate causes severe gastroenteritis, diarrhea, spasms, and paralysis




leading to death (VE 78).
                                    4-50

-------
     Chronic toxicity from soluble silver salts, is usually associated




with argyria, a permanent blue-grey discoloration of the skin caused by




deposited silver (EN 76, NA 76).  The silver deposited in tissues,




especially in the skin, is apparently retained there indefinitely (EN 76),




perhaps as a harmless silver-protein complex, or as silver sulfide or




selenide (VE 78).  If 1 gram of accumulated silver causes borderline




argyria, as postulated by the National Academy of Sciences, this level




should be reached after 50 years drinking water with 50 micrograms of




silver per liter, or after 91 years with water at 30 micrograms per liter




(NA 76).  Prolonged consumption of silver salts may also cause liver and




kidney damage and changes in blood cells (VE 78).








4.8.3.14  Thorium



     Thorium is a metal distributed in the environment in trace quantities




except in some ores.  It is not essential in human nutrition.  It is used




in industry and as a nuclear power source.  It was used in medicine.








     There are no data on acute toxicity in humans.  In animal studies,




thorium levels near 1 gram per kilogram of body weight cause death in half




of the animals given an oral dose (VE 78).








     Chronic toxicity appears limited to carcinogenesis associated with




the radioactivity of the thorium.  The various isotopes of thorium are



expected to vary greatly in toxicity considered on a per unit activity




basis (IN 79); all are expected to produce radiation related cancers.
                                    4-51

-------
4.8.3.15  Uranium



     Uranium is a metal widely distributed in the environment in trace




quantities.  It is not essential in human nutrition.  It is used in the



nuclear industry.








     Acute toxicity in humans has been estimated to occur,  based on kidney




damage, following absorption of 0.1 milligram per kilogram of body weight




and some deaths would be expected following absorption of 1 milligram per



kilogram of body weight (LU 58).  If 2Q% of the uranium in water is




absorbed, this would be equivalent to 17.5 milligrams and 175 milligrams




per liter of uranium, respectively, for a 70 kilogram man.   Oral doses of




10.8 milligrams of uranium (as uranyl nitrate hexahydrate)  apparently




caused no kidney damage (HU 69).  However, consumption of 470 milligrams




of uranium (1 gram of uranyl nitrate) caused vomiting, diarrhea and some



albuminuria (BU 55).








     It is apparently possible to build up a tolerance to uranium.  Spoor




cites reports from the medical literature of the 1890's where uranyl




nitrate was used to treat diabetes, starting with a conditioning dose of




about 60 milligrams of uranyl nitrate three times a day after meals and



maintaining treatment on up to 6 grams of uranyl nitrate a day (SP 68).



If such doses were given without conditioning, they would be expected to



be fatal.
                                   4-52

-------
     Chronic toxicity may also be related to enzyme poisoning in the kidney




(LU 58), with some liver damage as a result of that kidney damage (VE 78).




Animal experiments of chronic inhalation of uranium compounds for a year




show mild kidney changes associated with about 1  microgram of uranium per




gram of kidney.  Extending these results to a human kidney weight of 300



grams, absorption of 20$ of uranium in water and  deposition of 11% of




absorbed uranium in the kidney retained with a 15 day half-life (SP 73),




could cause chronic chemical toxicity in humans by consuming water with



about 315 micrograms of uranium per liter.








     Uranium can also cause chronic toxicity in the form of radiation




related carcinogenesis.  The various isotopes of uranium will vary greatly




in their carcinogenic potential as considered on a unit activity basis




(IN 79).  There is some question as to whether radiation-related cancer or




chemical toxicity will be the predominating response to some uranium




isotopes.








4.8.3.16  Vanadium




     Vanadium is a metal widely distributed at low concentrations in




nature.  It is not known to be essential to human nutrition.  It is used




industrially.  Vanadium salts are not very toxic  given orally (GO 78);



4.5 milligrams of vanadium per day as oxytartarovandanate caused no



symptoms when fed for a 16-month period (UN 77a).  There is no evidence of



chronic oral toxicity of vanadium (NA 77).
                                    4-53

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4.9  Summary



     Two types of radiological risk were considered: the maximum risk to




individuals and the collective risk to all exposed individuals.  At many



of the inactive sites, there is increased health risk to individuals




because of the presence of tailings, both for gamma ray exposures and



particularly for the risk due to inhaled radon decay products of (c.f.




Tables 4-3 and 4-4).








     Table 4-11 summarizes the local, regional, and national risks due to




radon decay products from the inactive sites.  In preparing Table 4-11 we




have supplemented the data in Table 4-2 with other analysis of population




exposure from tailings piles (FB 76-78) so as to include all sites.  All




of these estimates are based on current populations and therefore will




change with population growth as well as living patterns.  At present,




most of the potential effect is projected to occur in the regions near the




inactive tailings pile.  The national effect, however, is comparable.








     Compared to the risk from short half-life radon decay products from




radon emissions, the other radiological risks are much less significant.



At most, they increase by 10 percent the risk to the regional population.




The risk to the national population is much less.  This incremental risk



is small compared to the uncertainty in the estimated risk for lung cancer




death from the short half-life radon decay products, which is at least a



factor of two.
                                    4-54

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                                TABLE 4-11

        Summary — Risks Due to Radon Emissions  from Tailings  Piles

                   Short Half-Life Radon Decay Products
Deaths occurring within
  50 miles of site

Deaths occurring more than
  50 miles from site

     TOTAL
                               Estimated  Fatal  Cancers  (per  100 years)
                              Relative Risk               Absolute  Risk
                                 Model                       Model
150


 90

240
130


 40

170
                                   4-55

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     The nonradioactive toxic substances present in an inactive tailings




pile and their potential impact on public health and the environment must




be determined on a site-specific basis.  Those substances in tailings



which can move through ground water and which have the greatest potential




toxicity include the following:








         Arsenic, barium, cadmium, silver, chromium, lead, mercury,



molybdenum, selenium, nitrate, iron, vanadium.








     In addition, among radioactive substances, uranium is most likely to




be mobile in ground water, and radium and polonium are possibly mobile.
                                    4-56

-------
                         References for Chapter 4

(AR 79)    Archer,  V.E.,  "Factors  in Exposure  Response  Relationships  of
          Radon Daughter Injury," Proceedings of  the Mine  Safety  and
          Health Administration,  Workshop  on  Lung Cancer Epidemiology and
          Industrial Applications of Sputum Cytology,  November  14-16,
          1978, Colorado School of Mines Press, Golden, Colorado,  1979.

(BU 55)    Butterworth,  A.  The Significance and Value  of Uranium  in  Urine
          Analysis,  Trans.  Ass. Indstr.  Med.  Offrs. 5:36-43  (1955).

(BU 61)    Burden,  E.H.W.J.   The Toxicology of Nitrates and Nitrites  with
          Particular Reference to the Potability  of Water  Supplies.
          Analyst 86_:429-433 (1966).

(BU 78)    Bunger,  B.M.,  Barrick,  M.K., and Cook,  J.C.,  Life Table
          Methodology for Evaluating Radiation Risk.   CSD/ORP Technical
          Report No. 520/4-78-012,  USEPA,  Washington,  D.C. 1978.

(CH 79)    Chappell,  W.R., et al^,  Human Health Effects of Molybdenum in
          Drinking Water, EPA-600/1-79-006.  USEPA, Health Effects
          Research Laboratory, Cincinnati,  1979.

(DA 77)    D'Appolonia Consulting  Engineers,  Report 3, Environmental
          Effects of Present and  Proposed  Tailings Disposal  Practices,
          Split Rock Mill,  Jeffery City, Wyoming,  Volumes  I  and II.
          Project No.  RM 77-419,  1977.

(DR 78)    Dreesen, D.R., Marple,  M.L., and Kelley, N.E.,   Contaminant
          Transport, Revegetation,  and Trace  Element Studies at Inactive
          Uranium Mill Tailings Piles, pp.  111-139 in  Proceedings of the
          Symposium  on Uranium Mill Tailings  Management, Colorado State
          University,  Fort  Collins, Colorado  1978.

(EN 76)    Environmental Protection Agency.  National Interim Primary
          Drinking Water Regulations.  EPA-570/9-76-003.  USEPA, Office of
          Water Supply,  Washington, D.C. 1976.

(EN 79)    Environmental Protection Agency.  Cadmium Ambient  Water Quality
          Criteria.   Office of Water Planning and Standards,  USEPA,
          Washington,  D.C.  1979.

(EP 76)    EPA Policy Statement on the Relationship Between Radiation Dose
          and Effect,  41 F.R. 28409, July  9,  1976.

(EP 78)    "Indoor Radiation Exposure Due to Radium-226 in  Florida
          Phosphate  Lands."  EPA  520/4-78-013, U.S. EPA, Washington,  D.C.
          July 1979.
                                   4-57

-------
(EP ?8a)  "Response to Comments;  Guidance on Dose Limits for Persons
          Exposed to Transuranium Elements in the General  Environment,"
          EPA 520/4-78-010,  U.S.  EPA,  Washington,  D.C., 1978.

(EP 78b)   Investigation of Landfill  Leachate Pollutant  Attenuation by
          Soils.  EPA-600/2-78-158.   USEPA, Municipal Environmental
          Research Laboratory,  Cincinnati, Ohio  1978.

(SW 80)   Swift,  J.J. "Distant  Health  Risks from Uranium Mill  Tailings
          Radon", U.S. EPA,  Office of  Radiation  Programs,  Technical Note
          ORP/TAD-80-1, 1980

(FB 76-78)  Ford, Bacon and  Davis Utah,  Inc. Phase II-Title I  Engineering
            Assessment of Inactive Uranium Mill  Tailings,  DOE  Contract
            No.  E(05-1)-l658, Department of Energy,  Washington,  D.C.,
            1976-78.

(GE 79)   George, A.C. and Breslin,  A.J.,   "Distribution of Ambient Radon
          and Radon Daughters in New York and New Jersey Residences,"
          Proceedings of Natural Radiation Environment  III,  April 23-28,
          1978 (to be published), University of  Texas,  Houston,  Texas.

(GO 76)   Gosselin,  R.E.,  et al.,  Clinical Toxicology  of  Commercial
          Products,  Uth edition.   Williams and Wilkins  Co.,  Baltimore, MD.
          1976.

(GO 77)   Goyer,  R.A. and Mehlman,  M.A.  editors,   Toxicology of  Trace
          Elements,  Advances in Modern Toxicology,  Vol. 2.  John Wiley &
          Sons,  New York,  1977.

(HU 69)   Hursh,  J.B., et al.,   Oral Ingestion of Uranium  by Man,
          Health Physics 17:619-621  (1969).

(IN 79)   International Commission on  Radiological Protection,   Limits
          for Intakes of Radionuclides by Workers,  ICRP Publication 30,
          Pergamon Press,  New York,  1979.

(JO 63)   Johnstone, R.M.,  Metabolic  Inhibitors 2,  (1963) cited by
          Underwood, E.J., see  UN 77.

(KA 76)   Kaufman, R.F., Eadie,  G.G.,  and Russell,  C.R.,   "Effects of
          Uranium Mining and Milling on  Ground Water in the Grants
          Mineral Belt, New  Mexico."  Ground Water 14;296-308  (1976).

(LU 58)   Luessenhop, J. e_t  al.,   The  Toxicity in Man of Hexavalent
          Uranium Following  Intravenous  Administration, Amer.  J.
          Roentgenol. 79_:83-100  (1958).

(NA 72)   National Academy of Sciences,   Lead;   Airborne Lead  in
          Perspective. NAS-NRC,  Washington, D.C.,  1972.
                                   4-58

-------
(NA 72a)   National Academy of Sciences,   Accumulation of Nitrate,
          Committee on Nitrate Accumulation,  NAS-NRC,  Washington,  1972.

(NA 76)   "Health Effects of Alpha-Emitting Particles in the Respiratory
          Tract," EPA 520/4-76-013,   National Academy of Science,
          National Research Council,  Washington,  DC,  October 1976.

(NA 77)   National Academy of Sciences,   Drinking Water and Health,
          Part 1, Chapters 1-5,  NAS  Advisory Center  on Toxicology,
          Assembly of Life Sciences,  Washington,  1977.

(NR 79)   Draft Generic Environmental Impact Statement on Uranium  Milling,
          Volume II, NUREG-0511,  U.S. Nuclear Regulatory Commission,
          Washington, 1979.

(PU 77)   Purtymun,  W.D., Wienke,  C.L.,  and Dreesen,  D.R.,   "Geology  and
          Hydrology in the Vicinity of the Inactive Uranium Mill Tailings
          Pile, Ambrosia Lake, New Mexico,   LA-6839-MS  Los Alamos
          Scientific Laboratory,  New  Mexico,  1977.

(SI 45)   Silberstein, H.E.,   Radium  Poisoning.  AECD-2122,   USAEC
          Technical Information Division, Oak Ridge,  1945.

(SO 57)   Sollman, T.,  A Manual of Pharmacology, 8th edition,   W.B.
          Saunders Co., Philadelphia, 1957.

(SP 68)   Spoor,  N.L.,  Occupational  Hygiene Standards for Natural
          Uranium, AHSB(RP)77.  Radiological Protection Division,  UKAEA,
          Harwell, 1968.

(SP 73)   Spoor,  N.L. and Hursh,  J.B.,  Protection Criteria,  pp. 241-270
          in Uranium-Plutonium-Transplutonic Elements, H. C.  Hodge,
          J.N. Stannard and J.B.  Hursh,  editors,   Springer-Verlag,  New
          York, 1973.

(TE 60)   Terada, H., et al.,  Clinical Observations  of Chronic  Toxicosis
          by Arsenic, Nihon rinsho,  18:2394-2403, (1960),
          (EPA translation No. TR 106-74)

(UN 77)   "Sources and Effects of Ionizing Radiation,"  United Nations
          Scientific Committee on the Effects of Atomic Radiation,  1977,
          Report to the General Assembly, U.N. Publication E.77.IX.1,
          United Nations, NY.

(UN 77a)   Underwood, E.J.,  Trace Elements in Human and Animal
          Nutrition, Fourth Edition,   Academic Press,  New York,  1977.

(VE 78)   Venugopal, B. and Luckey, T.D.,  Metal Toxicity in Mammals
          .2, Chemical Toxicity of Metals and Metaloids, Plenum  Press,
          New York, 1978.
                                   4-59

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5.  ALTERNATIVE TAILINGS DISPOSAL CONTROL LEVELS








5.1  Introduction




     Standards of general application for protecting public health,



safety, and the environment must take account of reasonable and feasible




methods for controlling uranium mill tailings.  Because of the long



lifetimes of radiological contaminants,  and the presence of permanently




toxic nonradiological contaminants in tailings, it is important to




consider the longevity or permanence of control methods.








     As shown in Chapter U, the predominant health hazard is the release




of radon-222 into the atmosphere.  Techniques which provide a reasonable




degree of long-term control of radon releases also provide essentially




complete control of particulate releases and direct gamma radiation.



Therefore, this chapter primarily discusses control of the radon-222




releases and the water pathway, and the longevity of control.








     Alternatives for the degree of radon control that could be required




range from no control, i.e., leaving the sites as they are, to




essentially complete control, i.e., little or no radon release from



tailings.  For comparison of their costs, benefits, feasibility,



longevity, and other considerations in developing an appropriate




standard, three levels of control are examined:
                                   5-1

-------
     a.  No control (the existing situation).



     b.  Control radon releases to about the natural background rate.




     c.  Complete control (practically no release).








     Alternatives for the degree of control of potential water




contamination also range from no additional control  to complete



prevention.  For water,  the levels of control examined are:








     a.  No control (the existing situation).




     b.  Control of water contamination to a degree  comparable to other




         water quality programs.




     c.  Complete control (no contamination of water).








     The health protection the disposal system ultimately affords depends




on the control levels and the time over which they are maintained.  We




examined the technical and economic reasonability of requiring effective




control for:








     a.  several hundred years




     b.  hundreds to thousands of years



     c.  longer than tens of thousands of years
                                   5-2

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5.2  Control of Radon-222 Releases




     Radon release control methods range from simply placing a barrier




between the tailings and the atmosphere to more exotic treatments such as




incorporating them in a solid matrix, such as cement, or processing them



to remove the sources of radon.  Consideration should be given to




stabilization of barriers against erosion by wind and water, and



protection against intrusion by human activity.  Specifics of radon




control techniques are discussed more fully in Appendix B, where costs




are estimated of implementing various levels of control.  A general




discussion of radon control and the ancillary benefits of controlling



other potential hazard pathways follows.








5.2.1  Radon Control




     Release of radon-222 into the atmosphere can be controlled by




covering the tailings with an "impermeable" barrier (plastic) or enough




permeable material (soil) to slow the passage of radon through the




covering material so that, by radioactive decay the amount of radon




released is reduced.  In general, the more permeable the covering



material, the thicker must be the cover to achieve a given reduction in




radon release.  However, maintaining the integrity of thin impermeable



covers over periods of tens to hundreds of years or longer is highly



uncertain under possible chemical and physical stresses.
                                   5-3

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     Natural materials can be used,  such as soils,  clays,  gravels, or a



combination.  Generally clay-type material, especially when moist,




provides much greater resistance to the passage of radon than does an




equal thickness of soil or sand.  Table 5-1 shows the approximate



half-value-layer (HVL) of typical natural materials for reducing radon




releases.  The HVL is that thickness of cover material which reduces the




radon release to one half its value without the cover.  These HVL values




are nominal; the actual HVLs depend on soil composition, degree of




compaction, amount of moisture present, and other parameters.








     Figure 5-1 shows nominal curves for the percentage of radon which




would penetrate various thicknesses of different materials (FB 76-78).



Using the HVL concept, one can see that about 7 HVLs of cover are needed




to reduce radon releases to less than 1% of the uncovered rate, and about




10 HVLs reduce the release to less than 0.1?.  Radon reductions are




multiplicative when HVLs of the same or different materials are used.




For example, one HVL of soil plus one HVL of clay reduce radon releases




to 25% of the uncovered value (1/2x1/2=1 A).








     Uranium mills generally have been established close to the mines



from which their ore is obtained, and it is not unusual for other mines




also to be in the area.  Disposal of tailings from inactive processing




sites in these mines should be seriously considered.  The thick covers




and erosion protection that below-grade disposal in mines could provide




would offer virtually complete radon emission control for substantially

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                        TABLE 5-1



      Nominal Half-Value-Layers of Typical Natural

                                              (a)
          Materials  for Reducing Radon Releases






      Material                             HVL



Sandy, porous soil                      1.0 meters



Mid-range, typical Western Soil         0.5 meters



Well compacted,  moist soil              0.3 meters



Clay (moist)                            0.12 meters
(NR 79) Appendix K, Chapter 9 and 12.
                           5-5

-------
100
                         FIGURE 5-1
                                 A=SAIMDY SOIL (HVL = 1.0 M)
                                 B = SOIL (HVL = 0.5 M)
                                 C = COMPACTED, MOIST SOIL
                                                (HVL=0.3 M)
                                 D= MOIST CLAY (HVL=0.12 M)
                   2'3        4       5
                    COVER THICKNESS (METERS)
                                               5-6

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longer periods than could generally be expected using above-grade disposal




methods.  However, since mines are usually below the water table, elabor-



ate and costly ground water protection methods might be needed, and it is




not clear that effective methods are known.  Transportation hazards and




costs would be inevitable for this means of disposal.  Even where other-




wise suitable mines are near an inactive processing site, using them for




tailings disposal might preempt future development of the mine's residual




resources.








     Covering tailings in an above-ground depository, in a natural pit or




ravine, in a specially-excavated pit, in an open pit mine, or in a deep




mine are all variations of the basic radon-222 control method:  reduction




of radon releases by covering the emitting material.  Although any of




these variations can produce the desired initial reduction in radon




releases, the potential longevity of control and potential water




contamination must be considered in choosing a specific method.








5.2.2  Effects of Radon Control on Release of Airborne Particulates




     Since radon so readily penetrates permeable materials, radon control




methods will simultaneously control release of airborne particulates



resulting from resuspension of the material.  Either a thin impermeable



cover or a thicker natural material cover will prevent windblown partic-



ulates.  Any covering will prevent the spread of windblown tailings as




long as the integrity of that cover is maintained.  On the assumption
                                   5-7

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that some radon release control method will be required,  it is




unnecessary to discuss control of airborne particulates further.








5.2.3  Effects of Radon Control on Direct Gamma Radiation




     Covering tailings piles to reduce radon-222 releases will simultane-




ously reduce the direct gamma radiation from the piles.  Attenuation of



gamma radiation, as for radon, depends on the thickness of the cover;




i.e., the thicker the cover by a given material, the more gamma radiation




is reduced.  Figure 5-2 shows the nominal gamma radiation which passes




through a given thickness of compacted soil.  As indicated in Figure 5-2,




the half-value-layer of compacted soil for reducing gamma radiation from




tailings is about 0.3 feet.  The degree of soil compaction, moisture




content, type of soil, and other parameters all influence the attenuation




of gamma radiation.  A thin, impermeable cover, such as a plastic sheet,




will obviously not provide significant reduction of gamma radiation.  A




thicker cover of some gamma radiation attenuating material, such as soil,




can provide significant reduction.  Comparing the HVL's of soil for




reduction of radon releases and reduction of gamma radiation, one can see




that coverings of soil-like material thick enough to significantly reduce




radon emissions will greatly reduce gamma radiation.  Again, on the



assumption that some radon control method will be required, we will not



address controlling direct gamma radiation exposure from tailings piles




any further.
                                   5-8

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                 FIGURE 5-2
                                COMPACTED SOIL
                                        (HVL = 0.1 M)
0.1
0.2       0.3       0.4       0.5
 COVER THICKNESS (METERS)
 0.6

5-9

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5.2.4  Effects of Radon Control on Potential Water Contamination




     Covering uranium mill tailings piles to reduce radon-222 releases




can provide ancillary benefits toward control of potential contamination




of surface and ground water.  A cover will prevent the wind from blowing



tailings directly or indirectly into surface water.  Control of erosion




by precipitation, runoff, or streams may be achieved by the cover used to




reduce radon.  Infiltration of precipitation into the piles can be reduced




by the proper choice of coverings.  A thin, impermeable cover would



prevent infiltration of any precipitation as long as the cover remains




intact.  A thicker cover of natural materials, especially if clay-like




materials are used, might provide a barrier against infiltration, or



allow sufficient evaporation to occur so as to balance the precipitation.








     Covering tailings at sites below ground, i.e., in specially-dug




pits, open pit mines, or underground mines, can greatly benefit control



of surface water erosion and precipitation infiltration.  However, care



must be taken to avoid potential contamination of useable ground water by




radioactive and nonradioactive pollutants.  Thus, covering tailings to



reduce radon releases can provide some control of potential contamination




of surface and ground water, by controlling erosion and infiltration of



precipitation.
                                   5-10

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5.3  Control of Surface and Ground JWater Contamination




     Surface water contamination by windblown tailings can be prevented




by a suitable cover.  Control of erosion by streams or precipitation




could be achieved by contouring and covering the pile, and stabilizing



the surface.  If necessary, the pile could be moved to a site away from




existing streams and then covered.  Leaching of contaminants due to




infiltration by precipitation can be reduced with a cover of suitable




thickness and materials.








     The most difficult problem may be control of ground water




contamination due to direct contact with the tailings, and leaching of




the radioactive and nonradioactive contaminants.  Control of direct



contact with groundwater can be achieved through two general approaches.




The tailings can be placed far enough above the water table and its




predicted fluctuations to avoid direct contact.  The other approach would




be to impose an "impermeable" barrier between the tailings and the ground




water to prevent or reduce direct contact.  Obviously, where they are




needed, these control approaches are feasible only if the pile is moved.




Some of the existing tailings sites are probably already in a suitable




position with regard to the water table.  On the other hand, continuous



contact with ground water, or periodic contact as the water table



fluctuates, occurs at some other sites.








     There is evidence that ground water in the vicinity of some inactive




sites is already contaminated, probably due to seepage of the liquids
                                  5-11

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from tailings ponds during and following their period of active use.

Such seepage may now have slowed,  because the tailings ponds at inactive

sites have partially dried up.  However, leaching by precipitation

infiltrating uncovered tailings piles is still a possibility.^



     These techniques may be useful to prevent or reduce new

contamination of surface and ground water.  An already contaminated

aquifer, however, may be difficult if not impossible to remedy.  Ground

water hydrology can be manipulated, but the economic and technical

practicality of such remedial techniques is uncertain for general

application.  The only feasible control for general application would be

to monitor the quality of the aquifer and limit the use of its water, for

as long as necessary.  The duration of time this may be necessary depends

on the degree of contamination, the rate of ground water movement, the

amount of dilution and dispersion taking place, and the intended use of

the water.
 ^Based on very recent studies of tailings at some of the inactive
 sites, one investigator (MA 79) has suggested that contaminants may be
 moving to the surface of the piles, rather than down to the ground.  The
 studies are incomplete and unpublished; if confirmed, the findings would
 suggest that ground water contamination by long-term leaching is less
 likely than it would otherwise appear.  They would also suggest that
 contaminants may eventually penetrate a cover over the tailings, and be
 exposed at the surface.
                                   5-12

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5.1*  Longevity of Control




     Although various general approaches are available to control the




four pathways of potential hazard to people from tailings at inactive




sites, the longevity or permanence of the specific methods used to



implement these approaches is of prime concern.  Because of the long




lifetimes of the radiological contaminants (thorium-230 has a half-life




of about 80,000 years) and the presence of other toxic chemicals (which




never decay), the potential for harming people and the environment will




persist indefinitely.  The ultimate objective of a disposal program is




not only to reduce the potential hazards to an acceptable level now, but




also to assure that these potential hazards remain controlled for as long




as their source persists.  However, natural forces and human activities




could disrupt the tailings.








     In the following, we examine pertinent technical and social factors




for choosing among alternative periods for applying pollution control




standards for tailings disposal.  The costs of alternative degrees of




control longevity will be discussed in Chapter 6.








5.U.1  Effects of Natural Forces



     The means by which natural forces may disrupt attempts to isolate



radioactive waste have been discussed by several authors (EP 78, GS 78,



LU 78, NE 78, GS 80).  The factors affecting long-term performance are




numerous and interrelated, and include some over which people may not




have any influence.  In general, we believe stability against natural
                                  5-13

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forces could reasonably be expected for a few hundred to a few thousand




years by dealing with the problem on a case-by-case basis and taking into




account site-specific factors.  Predictions of future stability become




more uncertain as the time period increases.  Beyond several thousand



years, long-term geological processes and climatic change will determine



the stability and isolation of the residual radioactive material for most




"permanent" control methods.  Glaciation, volcanism, uplifting and




denuding of the earth's surface, and deposition of material are typical




of events that have occurred during the past 100,000 years and continue




to occur at present.








     Nelson and Shepherd, in a report for Argonne National Laboratories



entitled "Evaluation of Long-Term Stability of Uranium Mill Tailing




Disposal Alternatives" (NE 78) have considered the impact of natural




phenomena including earthquakes, floods, windstorms, tornadoes, and




glaciation.  By dispersing the tailings, such events could create a




potential for chronic exposure to their radioactive and nonradioactive




toxic constituents.  The following comments are summarized from their



report.








5.4.1.1  Earthquakes




     Earthquakes can damage caps and covers, as well as disrupt a barrier




under a disposal site.  The number and magnitude of earthquakes that have




occurred in an area provide information on the probability of earthquakes




in the future.  As with any natural phenomenon, the confidence that can
                                   5-14

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be placed on such predictions increases as the time period increases for




which reliable earthquake and faulting information is available.  The



likelihood of a control failure due to the occurrence of an earthquake



depends on the likelihood of an earthquake of a magnitude greater than




the design model earthquake.  However, even if a disposal plan were




designed on the basis of the maximum credible earthquake, a finite



probability of a larger earthquake would exist.  The likelihood of that




happening is small for short time periods and increases as the time




period considered increases.  If an earthquake occurs at a site, the




likelihood of releasing tailings to the environment depends on the nature




of the disposal plan.  In general, the possibility of a control failure




due to earthquakes would be high.  The magnitude of release,  however, may




not be great.  Choice of location and method of disposal of tailings




should be made with full consideration of the potential for and impact of




earthquakes.








5.4.1.2  Floods




     Flooding can result from large rainstorms, rapidly melting snow, or




from localized cloudbursts, and the failure mechanism associated with




floods is erosion.  Increase in soil moisture associated with a flood may



also contribute to instability of slopes, and lead to landslides.




Frequencies of floods and the "maximum probable flood" can be predicted




from historical stream flow data and hydro-meterological data.  Over




extremely long time periods, however, even the maximum probable flood can




be exceeded.  With changes in climate, the frequency of floods and the
                                   5-15

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maximum probable flood may change.  Large floods are not time-dependent.



Two large floods can happen in successive years if conditions are right,




although the probability is slight.  The effects of floods can be




cumulative if maintenance or corrective action is not employed.




Selection of disposal sites and methods should be made with full




consideration of the potential for and impact of floods.








5.4.1.3  Windstorms and Tornadoes




     The frequency and intensity of windstorms and tornadoes can be




predicted from historical records.  Such predictions, however, suffer




from the same uncertainties and statistical vagaries as do the




predictions for earthquakes and floods.  The primary impact on tailings




piles would be wind erosion of the cover or of the material itself.



Consideration of predicted wind environment is important for developing




site-specific disposal methods.  With a suitable cover or cap on the




tailings, and protection of the surface against wind erosion, the impact




of winds and tornadoes should be minimal.








5.4.1.4  Glaciation




     The characteristic movements of glaciers could totally disrupt an



above-ground or near-surface tailings depository.  Glaciers occur in



mountain valleys and as ice sheets, such as in Greenland.  Because of the




magnitude of the forces associated with glaciation and related effects,




it is doubtful that any portion of a surface depository could survive



even a small, relatively short-term glacier.  The likelihood of
                                   5-16

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continental glaciation in the Western U.S. even within a long-term period




is remote.  There have been four major advances of glaciers in the past



one million years, but there is no evidence of continental glaciation




south or west of the Missouri River.  There is, however, a possibility of



increased valley glaciation in mountainous regions in the West.  A




climatic change over a small area could result in an increase in valley




glaciers or small ice formations at higher elevations.  Several glaciers




exist at high elevations in the Rocky Mountain area today, and heavy




glacial activity existed in the mountains as recently as 10,000 years




ago.  A significant increase in valley glaciation is considered to be




remote within the short-term period, but is likely with a long-term




period.  Previously glaciated mountain valleys would be less desirable as




disposal sites than nonglaciated sites, such as flat terrain or valleys




created entirely by erosion.  The possibility of valley glaciation should




be considered in choosing surface or below-ground disposal methods.








5.4.2  Effects of Human Activity




     Disruption of tailings isolation as a result of human activity is




also a possibility.  The NRC has discussed the problem in Chapter 9 of




its DGEIS, especially with regard to the need for land use controls.



Building on top of a disposal site, excavation or drilling, and some uses




of the surface land, i.e., grazing, tilling, etc., could disrupt the



isolation or accelerate natural erosion processes.  It has even been




suggested that a disposal site should not be made more attractive to




human or animal habitation than the surrounding environs, and that
                                   5-17

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perhaps it should be left less attractive to discourage potential future

occupancy (SH 78).



     The PL 95-604 requires that the final disposal sites for residual

radioactive material be owned by an agency of the Federal Government and

licensed by the NRC (42 USC 7901).  Such Federal responsibility should

provide control of any human activity, which might disrupt isolation of

the tailings, for as long as the Federal responsibility is exercised.  In

its proposed criteria for management of radioactive wastes (FR 43), EPA

has stated that one should not plan to rely on institutional controls for

more than 100 years.



     In a paper entitled "An Assessment of the Long-Term Interaction of

Uranium Tailings With the Natural Environment" Lush, et al. (LU 78), have

discussed a philosophy of management from an historical viewpiont.  The

following are excerpts from that paper:
     "The present notion of man's ability to manage or control
     his surroundings beyond the confines of our cities is not
     recent.  This was evident in the classical or Roman
     civilization in the development of formal gardens and
     artificial irrigation schemes.  Our ability today to achieve
     control of our environment  has never been greater.
     Similarly, the need to control man's activity within this
     environment has never before risen to such an intensity.
     Nevertheless, our ability to control applies almost
     exclusively to human action and not to natural phenomenon.
     Also in the time frame of our present concern for the
     management and control of uranium mill tailings, there is
     insufficient evidence to show that mankind can exercise a
     sustained control of sufficient duration.
                                   5-18

-------
"Man's presence on earth was quite modest until the arrival
of Homo sapiens less than 60,000 years ago.  Even though
Neanderthal man was considered to have a rudimentary social
organization, his small numbers, (five million) afforded
only the puniest of efforts in environmental control.1
In contrasts, the recurrent glaciations of the world, each
of roughly 70,000 years duration were mammoth in extent.
These glaciations with their associated natural activities
are the outstanding geo-forces that occurred during man's
presence on earth.  The ability to effect a sustained
control over the environment is directly linked to man's
ability to effect a sustained control over his own
activities.  This we identify in the highest state of
achievement as civilization.  Throughout man's history, we
can detect no more than 2 dozen civilizations, all of which
occurred during the last 10,000 years.  Furthermore, the
greatest duration of any human civilization was less than
6,000 years and nearly one-half of these had less than 2,000
years duration.

"Management in popular usage has the connotation of success
in reaching one's objectives.  In this context, management
over a term of 100,000 years has no precedence in human
experience.  As noted earlier, no civilization has succeeded
in controlling human activity longer than 6000 years and
indeed no evidence exists for man's ability to control
immense natural events such as glaciations with their global
consequences.  Nevertheless, it can be said that some
presumed objectives of ancient man have been achieved over a
long term.  The burial of human remains of Neanderthal Man
for example, in a nearly intact form, has been achieved, in
the instances of our discoveries over 115,000 years.  The
excavation at other burial chambers in Egypt, China and
Greece show that for those people their long-term objectives
were won for periods up to 2500 years.  Even with these
achievements in isolated instances, we have no way of
knowing what success rate has been achieved.  How many
Neanderthal burials were there?  How many burial tombs of
ancient emperors go undetected?

"From the above examples, we see an achievement of
management objectives by chance rather than by control since
modern man rather amorally has no acceptance of ancient
man's desire for the sustained burial of his remains.  This
facet leads to the question of management for whom?  To what
    world population today is 4.1 billion people
                              5-19

-------
     extent are we  to  carry forward  the mores  and  beliefs  of this
     era into another  era 100,000 years later.  While  proof
     "exists" that  waste dispersed into the  environment is
     undesirable and hazardous,  what can  we  use as a basis for
     constituting the  notion of  harm for  a society 100,000 years
     hence?  To what extent will our social  and scientific dogma
     be acceptable  in  100,000 years  or even  10,000 years?   To
     what extent will  our presence on the earth in population
     scale and distribution be a significant factor in achieving
     management as  we  know it today?

     "Prior to the  early 1900's, management  as a science or theme
     of human activity did not exist. Up until that time,
     attempts were  made by Adam  Smith and others in conditioning
     social thinking towards the concept  of  management for the
     factors of production in an embryo industrial society.  It
     took about 200 years to effect  the changes he propounded.
     Thus, it can be presumed that our present concept of
     management has a  life no longer than, say, 200 years.  In
     this regard, the  probable limits to  our management (as
     presently conceived) of uranium mine tailings would not
     exceed 200 years.  A detention  or control beyond  that period
     would need to  rely on chance  or on natural
     geophysical/geochemical forces."
     Thus,  institutional control of disposal sites to prevent intentional

or unintentional degradation and intrusion by human activity, although

required by PL 95-604, may be argued to be a reasonable expectation for

perhaps a few hundred years.  During the period of effective insitutional

control, however,  it should be possible to detect and remedy the minor

effect of natural forces, such as wind or water erosion.  Demonstrating

isolation stability, or, if required,  remedying a situation to achieve

stability,  during the period of effective institutional control should

provide some assurance of continued stability against natural forces for

a longer period of time.  Selecting disposal sites to isolate tailings

from expected habitation and land-use patterns, at remote locations or
                                  5-20

-------
deep underground locations, or both, is one way to provide additional




protection against degradation and intrusion by human activity after



institutional control has become ineffective.
                                  5-21

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5.5  Summary




     Control of radon releases can be achieved by use of barriers or




coverings over the tailings piles.  Methods used to control radon will



also control release of airborne particulates and direct gamma radiation.




Alternative methods for controlling radon releases by this approach are




use of above ground sites, natural pits or ravines, specially-dug pits,




open pit mines, and underground mines.  Longevity of control and




potential water contamination should be considered in selecting a



specific method.








     Water contamination by surface water erosion or infiltration of




precipitation can be controlled by proper siting and covering.  Leaching




through contact with ground water can be controlled by locating the



tailings away from ground water or by imposing a barrier between the




tailings and ground water.  Although hydrology could be manipulated, as a




general rule potential exposure to ground water that is already contam-




inated might be controlled best by monitoring aquifers and controlling




future drilling or water uses.








     Longevity of control must be a prime consideration in selecting



control methods.  Although the ultimate objective is to assure control




for as long as the material is potentially hazardous, because of




technical limitations control may not be reasonably expected for more




than a few thousand years.  This assumes proper consideration of site and




engineering characteristics, and effective institutional control for the
                                   5-22

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short term.  Beyond the period in which control of tailings may be a




reasonable expectation, continued control must be assumed to rely on




chance or natural events.
                                  5-23

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                        References for Chapter 5
(FR 43)   Federal  Register  43.  pp.  53262-53267,  November  15,  1978.

(EP 78)   U.S.  Environmental Protection  Agency,  June  1978,  "State of
         Geological Knowledge  Regarding Potential  Transport  of
         High-Level Radioactive  Waste From Deep Continental
         Repositories,"  Report EPA 520/4-78-004.

(FB 76-78)   Ford,  Bacon, and Davis,  Utah,  Inc.,  "Phase II-Title  1,
            Engineering  Assessment of Inactive  Uranium Mill  Tailings,"
            20 contract  reports  for Department  of  Energy Contract
            No. E(05-1)-1658,  1976-1978.

(GS 78)   U.S.  Geological Survey,  1978,  "Geologic Disposal of High-Level
         Radioactive Wastes — Earth-Science  Perspectives,"
         Circular 779.

(GS 80)   U.S.  Geological Survey,  1980,  "Isolation  of Uranium Mill
         Tailings and their Component Radionuclides  from the
         Biosphere," by  Edward Landa, Circular  814.

(LU 78)   Lush  et al^, 1978, "An  Assessment of the  Long-Term  Interaction
         of Uranium Tailings With the Natural Environment" from
         Proceedings of  the Seminars on Management,  Stabilization  and
         Environmental Impact  of Uranium Mill Tailings,  The  OECD
         Nuclear Energy  Agency,  pp.  373-398.

(MA 79)   Markos,  G., 1979, "Geochemical Mobility and Transfer of
         Contaminants in Uranium Mill Tailings," from Proceedings  of
         the Second Symposium  on Uranium Mill Tailings Management,
         Colorado State  Univ., Nov.  1979.

(NE 78)   Nelson,  J.D., Shepherd,  T.A.,  April  1979, "Evaluation of
         Long-Term Stability of  Uranium Tailing Disposal Alternatives,"
         Civil Engineering Department,  Colorado State University,
         prepared for Argonne  National  Laboratory.

(NR 79)   U.S.  Nuclear Regulatory Commission,  April 1979, "Generic
         Environmental Impact  Statement on Uranium Milling," NUREG-0511.

(SC 74)   Schiager, K.J., July  1974,  "Analysis of Radiation Exposures on
         or Near Uranium Mill  Tailings  Piles,"  in  Radiation  Data and
         Reports, pp. 411-425-

(SH 78)   Shreve,  J.D., Jr., July 1978,  in Proceedings of the Seminar on
         Management, Stabilization and  Environmental Impact  of Uranium
         Mill  Tailings,  the OECD Nuclear Energy Agency,  p. 350.
                                  5-24

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6.   MONETARY COSTS AND THE EFFECTS OF TAILINGS DISPOSAL








     In Chapter 5 we discussed disposal methods to control the potential




hazards of uranium mill tailings piles at inactive processing sites.  As a




basis for further analysis, we defined three alternative conceptual levels




of control for radon-222 releases (the principal hazard) and three




alternative conceptual levels of control for ground water contamination.



We also discussed the need for long-term control and some of the




uncertainties which may affect it.  In this chapter we present the range




of monetary costs for alternative pollutant control levels.  We also




discuss the longevity characteristics of disposal methods, the potential




environmental impact of control actions, occupational hazards, and effects




of the disposal program on the economy.

-------
6.1  Estimated Costs




     Cost estimates are based on an assumed inactive uranium mill tailings




pile whose area, volume, and weight are approximately the average values




for the existing 21 inactive uranium mill tailings sites.  This "average"




pile has a surface area of a little more than 19 hectares (190,000m^,  or



4? acres), contains ?80,000m3 (1 million yd3) of uranium mill tailings,




and weighs 1.3 million short tons.  The configuration of the pile is




assumed to be a truncated pyramid with a base approximately 440m on a side,



including the embankments.  The radon-222 release rate is assumed to be




1J50 pCi/m^-sec.  More detail on the "average" pile is given in




Appendix B.  Cost estimates for a tailings pile of different size can be




scaled from the "average" pile, by using the unit costs developed for




individual tasks and the purchase of specific items, which are presented




in Appendix B.  These include earth work, liners and caps, stabilizers,




fencing, irrigation, matrix fixation, tailings transportation, discount




rate, discounted value of future costs, and land costs.  The unit costs




are used to estimate the costs of applying various control methods to the



"average" tailings pile.








     The general control alternatives considered in this EIS are:








     (1) Leaving the uranium mill tailings where they are, but restricting




         access to the site.  In addition, particulate releases may be




         reduced by stabilizing the surfaces of the pile.
                                    6-2

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     (2) Covering the tailings pile at the existing location to control



         radon-222 releases, participate releases,  gamma radiation,  and to




         limit water contamination.








     (3) Transporting the tailings to a new site,  placing them in a



         specially-excavated pit having a surface that is impervious to




         moisture, and covering the tailings to control radon releases,




         particulate releases, and gamma radiation.








     (4) Transporting the tailings for deep disposal in a nearby open-pit




         mine or deep mine, or treating the tailings to remove radium.



         This option provides long-term control of radon releases,




         particulate releases, and gamma radiation.








     Numerous methods may be postulated for achieving each control option.




Combinations of these methods provide many alternative ways of estimating




the costs of achieving each of the general control options.  Therefore,




disposal costs depend on the general control option, and on the specific



control level within each option.  For simplicity,  only the least and the



most expensive total costs for each combination of a general option and a




specific radon control level have been computed.  These costs are




summarized in Table 6-1 (see Appendix B for the details of their



calculation).
                                    6-3

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     The total costs shown in Table 6-1  do not necessarily represent




typical conditions at any of the actual  inactive mill  tailings sites,  but



the range of costs covers the range of possibilities.   For example,  in the



least expensive method for satisfying control options  2 and 3 (for all




radon control levels), we assume vegetation will be used for surface



stabilization, and neither irrigation nor the purchase of a suitable top




soil will be required.  The most expensive surface stabilization method




under control options 2 and 3 uses rip rap.
                                    6-4

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-------
6.2  Estimated Health Benefits




     The benefits of implementing various disposal options can be described




in terms of how much they reduce potential harmful effects, and for how



long.  Under the first option — no control other than fencing, or surface




stabilization and a fence — there are no reductions in releases from the




tailings to air, land, or water.  Controlling access to land near the pile




would reduce doses only to those few people who might otherwise live or




work there.  As discussed in Chapter 5, however, this limited benefit




depends on institutional control and should not reasonably be expected to




persist for more than a few centuries.








     Under the second option — covering the tailings at the existing




site — the benefit of reduced radon release is directly proportional to




the degree of reduction.  For example, assuming the uncontrolled radon




release rate is 450 pCi/m^-sec, control to a level of 10 pCi/m^-sec




would avert ^°A50 (about 98$) of the potential health effects of radon




emission from the uncontrolled tailings pile.  Controlling radon releases



to any significant degree will also prevent release of particulates and



reduce direct gamma radiation to negligible levels.  Suitable covers will



provide ancillary protection for surface and ground water by limiting




infiltration of precipitation.  The need for more specific water  .




protection methods depends on characteristics of the site.
                                    6-6

-------
     The third disposal option — moving the tailings to a new,  below-grade




site, with a liner if needed — would provide specific control of potential



ground and surface water hazards.  The benefits of this option are reduced




radon health impacts, elimination of particulate and direct gamma radiation




health impacts, and control of potential ground and surface water impact.








     The fourth option is acid leaching to concentrate the radium, which




would then be subject to special disposal procedures (see Appendix B for




details), or deep disposal of the mill tailings.  In principle,  this




option provides the best prospect of long-term control of all options




investigated, but its practicality is the most uncertain.  If effective,




it could provide long-term control of radon releases, particulate releases,




and gamma radiation,  as well as control of potential ground and  surface




water contamination.








     In describing these benefits, we assume the control methods will




perform in the expected manner.  A summary of the presumed benefits of the




various control options is given in Table 6-2.
                                    6-7

-------
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-------
6.3  Longevity of Control



     In Chapter 5 (Sec. 5.4) we discussed longevity of control and the




effects of natural forces and human activity on longevity.  Although the




ultimate objective would be to assure control for as long as the material




is potentially hazardous, we cannot reasonably expect institutional control




to last for more than a few hundred years.  Lasting effectiveness depends




on physical disposal methods, proper consideration of site conditions, and




verification of disposal performance over the short term.  Beyond the




period control may be a reasonable expectation, continued control must be




assumed to rely on chance or natural events.








     A review of estimated control costs (this chapter and Appendix B)




shows that they depend more on the specific methods than on the degree of




radon control.  That is, the range of costs using different methods for a




given radon control level is greater than the range in costs for different




radon control levels.  Generally, those methods are most costly which, if




they performed as expected, would provide control for the longest periods




of time.  Therefore, the longevity objective may be the primary factor in




determining the actual cost of control.








     Some of the tailings disposal methods discussed in Chapters 5 and 6




and Appendix B are expected to last much longer than others.  Generally,




the thicker the cover, the longer control will be effective.  Thin covers




of artificial materials can greatly reduce radon releases but are not




expected to last very long.  Stabilizing a tailings pile's surface against
                                    6-9

-------
wind and water erosion is a key factor in the longevity of control




effectiveness for disposal at or near the earth's surface.  Stabilization




requires careful site selection and durable surface treatments to inhibit




erosion.  Disposal in a suitable location deep underground appears, in




principle, to be an even more promising way of avoiding disruption of




tailings by natural events or people.








     In general, below-grade disposal should be less subject to erosion




than disposal above-grade.  Furthermore, since all the tailings piles at




inactive processing sites are now above-grade, disposing of them below-




grade generally implies choosing new locations.  This would present




opportunities for finding particularly suitable sites.  In practice,




however, site-specific conditions can blur these distinctions.  At some




sites, above-grade disposal techniques may offer the stability more




characteristic of below-grade disposal.








     The longevity of a control method is difficult to specify quanti-




tatively.  We expect certain methods to last longer than others, but



experience with all control methods is quite limited, expecially



considering the time tailings will remain hazardous.  We believe the




characteristic longevity we may expect for above-grade disposal is hundreds




to thousands of years, for below-grade disposal is thousands of years, and




for deep disposal tens of thousands of years or more.  Potential hazards




will increase as control is partially or completely lost, so the benefits




of control depend directly on how long the controls will last.  Since
                                    6-10

-------
longevity can be described only broadly,  it is not possible to directly




relate the costs of specific long-lasting control methods to estimates of




the adverse health effects they will avoid.  However,  the goal is to



isolate tailings for as long as may reasonably be done,  and thereby avoid



future harm for at least that period.  For this reason,  disposal sites and



specific control methods should be selected with the primary emphasis on




the longevity of tailings isolation.
                                   6-11

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6.4  Environmental Impacts of Control Actions




     There will be adverse environmental impacts due to cleanup,




transportation, and final disposal of uranium mill tailings.  Whenever the




tailings are disturbed in the cleanup process, by excavating, hauling,



etc., there is a potential for increased airborne particulates.  Radon-222




releases might also be increased temporarily as tailings are uncovered or




piled in a new physical arrangement.  Careful attention to dust control




will mitigate the airborne particulate problem.  There might also be




increased erosion by surface runoff and other natural forces.  Spillage of




tailings or other contaminated materials is probable, and good house-




keeping practices will be needed to assure they are cleaned up and not




spread around the environment.








     Cleanup of contaminated land areas will require trucking material to




a disposal site, thereby increasing road traffic, dust, noise, fumes, and




the accident potential.  Removal of a tailings pile to a new location will




incur similar risks.  Disruption of vegetation at a new site, or when



obtaining material to cover the tailings, is an adverse impact.  However,




these are temporary effects, since they occur only during the cleanup and



disposal operation.  Compared to the long-term impact of uncontrolled



tailings, these temporary effects, if reduced as much as is practical,




could be considered negligible.
                                    6-12

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6.5  Occupational Hazards



     In addition to the temporary adverse environmental impact, there will




be hazards to workers who implement the tailings controls.  Workers who




clean and move uranium tailings will have higher exposure to gamma




radiation and radioactive airborne particulates than most others in



earthmoving occupations.  Usual health physics procedures to control




radiation exposures will have to be employed (HA Ip).  Hazards from using




trucks and other earth moving equipment will be similar to those in any




large scale earth moving project.  Again, these are temporary aspects of




the cleanup and disposal operation, and,  with proper care, may be




negligible in comparison to the long-term impact of uncontrolled tailings.
                                   6-13

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6.6  Economic Considerations at the Local Level



     Somewhat offsetting the temporary adverse environmental impacts and



occupational hazards is the possibility of economic gains in the locality



of the mill tailings sites.  If there is unemployment in the area, the



cleanup activities may provide temporary employment opportunities.  There



may also be an increase in business activity in the local area.  Con-



taminated land and structures may be made available to the local community



as a result of the cleanup program.  However, under the terms of



Sec. 104(f)(2) of PL 95-60U, the disposal site will be licensed by the



NRC, which may limit or prohibit its public use.  Since public funds



expended on tailings control will be unavailable for other uses, local



economic gains may be offset by dampening of other national economic



sectors.
                                    6-14

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                          Reference for Chapter 6

(HA Ip)   Hans,  J.M.,  Jr.,  Burris,  E.,  Gorsuch,  T.,  "Radioactive Waste
         Management at  the Former  Shiprock Uranium  Mill  Site,"
         Environmental  Protection  Agency Technical  Note  (in preparation)
                                   6-15

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7.  CONSIDERATIONS FOR CLEANUP OF CONTAMINATED LAND AND BUILDINGS





7.1  Introduction


     Land areas have been contaminated by wind- and water-borne tailings.


Tailings disposal will include disposal of some contaminated soils.  If the


control method chosen for disposal of a tailings pile requires moving it,


then contaminated soil beneath the pile must also be disposed of.





     Buildings have also been contaminated by wind- and water-borne


tailings, and by the deliberate use of tailings as fill under and around
                                      *

the structures.  Buildings that were once part of the mill operation are


also contaminated to various degrees.





     This chapter considers information pertinent to setting standards for


cleanup of contaminated open land and buildings.

-------
7.2  Off-Site Contamination




     In Sec. 3-3.3 we discussed the results of a study to determine the




specific locations of uranium mill tailings in communities near inactive




processing sites.  Table 3-9 indicates that of the 7,583 radiation



anomalies (a radiation anomaly is a gamma radiation level higher than



normal) detected in the regions surveyed with the mobile gamma radiation




scanner, 1,319 of these are caused by mill tailings,  644 are due to a




radioactive source (including luminous dial alarm clocks and mined




uranium), 904 are due to naturally-occurring radioactivity, and the cause



of 4,716 anomalies is unknown.








     These data do not include Grand Junction, Colorado, where large-scale




use of tailings occurred and a Federal/State remedial action program for




affected buildings is being conducted.  In Mesa County, where Grand




Junction is located, over 25,000 locations had been screened to identify




areas of possible tailings use as of October 15, 1978 (GJ 79).  More than



6,000 locations had some tailings on the property; the other, 19,000 did




not have any tailings.  Of the locations with tailings, about 800 are




expected to receive remedial action, 200 more qualify for remedial action



but the property owners will not apply, and the remaining approximately




5,000 have radiation levels below the program criteria for remedial action.




In Mesa County there are also places where tailings were used in construc-




tion of sewer and water lines, streets, and other projects, which will be




eligible for remedial actions under PL 95-604.
                                    7-2

-------
     The extent of contamination near the inactive processing sites due to




erosion of tailings piles by wind and water was determined through gamma




radiation surveys.  Table 3-10 summarizes the results.  More than 5,000



acres were found to have gamma radiation levels exceeding the normal




background.  The contaminated area defined by gamma radiation levels equal




to or greater than 10 uR/hr above background is more than 2,000 acres.




This figure does not include the areas of tailings piles, which is about



1,000 acres.








     The seriousness of the off-site contamination depends, of course, on




the amount of contamination and the potential exposure to people.  The




amount of land and number of buildings that will require cleanup will be




determined by the cleanup standards selected.
                                    7-3

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7.3  Potential Hazards of Off-site Contamination




     The greatest hazard from tailings on open lands is increased levels




of radon decay products in buildings.  Exposure to direct gamma radiation



and contamination of drinking water and food may also occur, but generally




will be of less concern.








     In Chapter 4 we discussed the health risk associated with radon decay




products.  Their concentration in an existing or future building will




depend on the radium concentration in the soil under or adjacent to it.




However, so many other factors affect the indoor radon decay product



concentration that a useful correlation with the radium in soil is




difficult to establish.  Nevertheless, Healy and Rogers (HE 78) analyzed




exposure pathways due to radium in soils, whether naturally-occurring or




as contamination.  They argue that one might expect indoor radon decay




product concentrations of 0.01 WL for soils with radium concentrations of




1-3 pCi/gm to a depth of at least one meter.  NRC estimates (NR 79) that




3-5 pCi/gm of radium can cause indoor concentrations of 0.01 WL.  Although



both of these calculations are approximations, radium concentrations near



the lower end of these ranges correspond to common natural soil conditions.



Therefore, where indoor radon decay product concentrations are only




slightly elevated, radon sources other than tailings may be the dominant




causes, so remedial action for tailings may have little beneficial effect.




Furthermore, cleaning contaminated open land will not eliminate elevated




radon decay product levels in future buildings, but generally will reduce




their degree of occurrence.

-------
     Tailings also emit gamma radiation, which can penetrate the body from



the outside.  We expect the indoor radon decay product concentration




standards generally will be met by removing tailings from the building,



and this will eliminate any indoor gamma radiation problem.  For some




buildings, however, complete tailings removal may not be a practical means




of lowering the indoor radon decay product concentration, more for




engineering reasons than for cost.  Alternate methods, such as air



cleaning, improving ventilation, or applying sealants to the walls and




floors are available.  If these are used, standards will be needed to




limit gamma radiation exposure of the occupants.








     Natural or contaminated soils with radium concentrations of 5 pCi/gm




through several feet down can also give exposure rates from gamma radiation




of about 80 mR/yr (NC 76).  Exposure rates are proportionately higher or




lower for other concentrations, and decrease as the layer of radium-




containing material becomes thinner, or is covered over by other materials.




The potential for causing elevated indoor radon decay product levels in




future buildings on such soils also depends on these factors.  Therefore,



cleanup standards for open land should take account of both the



concentration and the thickness of the contamination.








     Each gram of natural uranium contains 330,000 pCi of U-238 and




15,000 pCi of U-235.  Because it appears in relatively small proportion,




U-235 and its radioactive decay products usually may be ignored in




evaluating the hazard of uranium tailings.  The dominant hazard from
                                    7-5

-------
tailings of the usual composition is due to decay products of U-238,




including radium-226 and its decay products.  Other radioactive substances




in the tailings will ordinarily pose much less risk to health than that



from radium-226.








     The total protection provided by a standard based on radium-226




depends on the extent to which radium has been separated from other radio-




active substances, such as thorium and the U-235 decay products, during ore




processing.  If significant separation occurs, radium-226 concentration in




the residual material may not be an adequate measure of the radiation




hazard.  For example, thorium separates from radium in uranium mills using




the acid leach process.  Although thorium-230 and radium-226 occur in ore




in about equal amounts of radioactivity, thorium compounds are more soluble




in acid.  Therefore, thorium radioactivity concentrations in the wastewater




can be thousands of times higher than for radium, and more thorium may then




seep through the pile to the soil below (RA 78).  However, chemical inter-




action of thorium with the soils is expected to retard further movement



(GS Ip).








     At least one of the processing sites covered under Public Law 95-604




(Canonsburg, Pa.) may have tailings containing higher than usual




proportions of U-235 decay products.  Although little is known about the




environmental pathways and biological effects of these radionuclides,




site-specific information on their concentrations suggests they are not




likely to be a determining factor in clean up decisions (DO 78).  This is




because the U-238 decay products are present in greater amounts.
                                    7-6

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7.4  Remedial Actions and Costs



     The only permanent remedial action that will avoid the hazards from




contaminated land and buildings would be to remove uranium mill tailings



from under and around buildings, and from open land, and to dispose of




them in the tailings pile.  The costs and complexity of tailings removal




from buildings depends on the amount of tailings and their location




relative to the structure.  For example, tailings used as backfill around




the outside of a foundation can be removed easily at a relatively low




cost.  On the other hand, removing tailings from under a floor or



foundation involves the more complex and costly procedure of breaking up




concrete to reach the tailings.  In 1972, Congress enacted PL 92-314,




authorizing a remedial action program for buildings in Grand Junction,




Colorado, which were affected by that community's extensive use of




tailings in construction.  Experience gained through seven years of that




program illustrates the remedial action costs that may be incurred for



similar situations in other places under PL 95-604.  In the Grand Junction




remedial action program the average cost to treat a residential structure




has been about $13,500, and ranged from $540 to $41,000 (GJ 79).




Remediation for commercial structures averaged about $3^,500, with a range



of $6,600 to $107,000.  Schools averaged about $92,900, and ranged from



$19,000 to $500,000.  The total cost in Grand Junction through September



30, 1978, was almost $7,000,000.  It is estimated that the final total




cost for about 800 buildings may be about $17,000,000 (GJ 79).
                                    7-7

-------
     For the lands and buildings included in the Phase II study,  estimated




cleanup costs for off-site contamination were about $7,000,000 (FB 76-78),




and for the Canonsburg, PA., area were about $3,400,000 (FB 79).   Because




the Phase II estimates were based on interim cleanup criteria (for doing




an engineering assessment), they may indicate only the approximate costs



under a final standard.
                                    7-8

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7.5  Previous Standards for Indoor Radon Decay Product Concentration




     Government agencies of the United States and Canada have previously




published remedial action criteria for radon decay product concentrations



in buildings.








     The U.S. Surgeon General's 1970 remedial action guidance for Grand




Junction, Colorado applies to buildings on or containing uranium mill




tailings (PE 70).  EPA's guidance to the State of Florida applies to




buildings on radium-bearing phosphate lands (FR 4*0.  Each set of guides




has three levels: radon decay product concentrations above the high level



require action; those below the low level do not; local factors determine



the action required for buildings where the concentration is between these



levels.








     The Surgeon General's Guides are implemented in the Department of




Energy's regulations for remedial action at Grand Junction, Colorado




(10 CFR 712).  In effect, they adopt the lower level as an action level




for schools and residences, and the mid-point between the lower and upper



levels as an action level for other buildings.  This difference in action



levels recognizes the desired added protection for children and occupancy




period differences for residences and commercial buildings.  For radon



decay product concentrations these action levels are 0.01 WL and 0.03 WL,




respectively, above background.  The average background indoor radon decay




product concentration determined for use in the Grand Junction remedial



action program is 0.007 WL.
                                    7-9

-------
     The Canadian cleanup criteria (AE 77)  and the EPA recommendations for




residences on phosphate lands in Florida require remedial action for




indoor radon decay product concentrations greater than 0.02 WL (including




background).  The EPA guidance further recommends that concentrations




below 0.02 WL be reduced as low as is reasonably achievable.  Reductions




below 0.005 WL above the normal average background (for nearby lands in




Florida) of 0.004 WL are not generally justified in the Florida phosphate




lands.  In effect, then, for Florida EPA has recommended: remedial action




in all cases above 0.02 WL: action generally unjustified at concentrations




less than 0.009 WL; and for intermediate levels, action is left to the



judgment of local officials.








     In Chapter 3 we discussed surveys conducted to find buildings which




may be affected by tailings for which remedial actions may be conducted




under PL 95-604.  These surveys show a variety of affected structures,




whose elevated radiation levels have several different causes.  The total




number of buildings that will be eligible under PL 95-604 is not fully



established, but we believe they are fewer or comparable in number to



those in Grand Junction.
                                    7-10

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7.6  Normal Indoor Radon Decay Product Concentrations




     The indoor radon decay product concentration of a building affected




by tailings is the sum of contributions from tailings and from the natural




environment.  These contributions cannot be distinguished from one




another.  As we shall discuss in Section 8.2, knowledge of the




characteristics of radon decay product concentrations in normal buildings




is very useful in deciding the best form for a remedial action standard,



and in choosing a practical action level.








     The most complete studies of normal indoor radon decay product




concentrations in the United States were performed on buildings in Grand




Junction, Colorado (PE 77), New Jersey and New York (GE 78), and Florida




(PL 78).  The samples and measurement techniques of these studies are not




exactly comparable, however.  The New Jersey-New York buildings studied




were residences, mostly single-family, one or two story buildings.  The




Grand Junction sample was mainly houses, about half of which had basements




(CO 79).  The reported Grand Junction data are for the lowest "habitable




portion" of the building.  The Florida sample is single-family houses



without basements.








     Some results from these studies are summarized in Table 7-1.  In all



cases, the reported concentrations are the average of measurements taken




over a year.  The data indicate wide variations in normal indoor radon




decay product concentrations within each sample, even for a relatively




uniform sample of buildings.  Furthermore, the New Jersey-New York data
                                   7-11

-------
show that ground-level concentrations are about half of those in the




basement.  (An unpublished analysis of the Grand Junction data shows a




similar effect (CO 79).)








     Many buildings in the northeastern and western United States, where



the sites covered under PL 95-604 predominantly are located, have




basements.  For these buildings especially, the most important conclusions




we draw from these studies are the following:




     1.  Normal indoor radon decay product concentrations are very




variable.




     2.  Concentrations greater than 0.01 WL in a useable part of a normal




building are common.




     3.  Though less common, it is not rare for normal concentrations to




exceed 0.015 WL.
                                    7-12

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                                 TABLE 7-1

             Average^Annual Radon Decay Product Concentrations
                            in Normal Buildings
Grand Junction, Colorado(a)

     Sample:  29 buildings, mostly houses,  about half with basements.
     Range:            0.002-0.017 WL
     Median:          0.007 WL
     Above 0.01 WL:   30$
     Above 0.015 WL:   10$ (approx.)


New Jersey-New York(b)

     Sample:  21 houses,  mostly single-family with full basements.
                           Cellar                       First Floor
     Range:            0.0017 - 0.027 WL              0.0017 - 0.013 WL
     Median:          0.008 WL                       0.004 WL
     Above 0.01 WL:   40$                            8$
     Above 0.015 WL:   20$                            2%
Florida(c)

     Sample:  28 single-family residences,  without basements.
     Range:           0.001  - 0.012 WL
     Median:          0.0035 WL
     Above 0.01 WL:   3$
     Above 0.015 WL:   0$
(^References (PE 77) and (CO 79).

(^Reference (GE 78).

(^Reference (FL 78).
                                   7-13

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7.7  Practicality of Alternative Remedial Action Standards for Buildings



     We may use experience in the Grand Junction program to estimate the




scope of a cleanup program for tailings under alternative remedial action




criteria.  Table 7-2 gives the Grand Junction program's results (CO 79)




for buildings having tailings for which radon decay product measurements




have been made.  For residences and schools (R/S),  the remedial action




level is 0.01 WL above background.  Among the 463 R/S sampled, 217 were




found eligible for remedial action.  If the action level had been 0.005 WL




above background, the eligible number would have been 61 more, an increase




of 2Q%.  Table 7-2 also shows that some R/S for which remedial actions




have been performed have not yet been brought below the action level.  Had




the action level been 0.005 instead of 0.01 WL above background, an




additional 51 R/S would need further remedial work.  Table 7-2 shows 40 or




52 additional buildings other than R/S would have been eligible if the




action level for them had been 0.01 WL or 0.005 WL above background,




respectively.  This is an increase of 114$ or 149?, respectively, in the



program for that category of buildings.  The table also shows that under



the lower action levels additional work would be needed for 17 to 26 of



the buildings other than R/S on which remedial action has already been



performed.
                                    7-14

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                                   TABLE 7-2
             Experience with Grand Junction Remedial Action Program
  Non-Eligible

Residences and Schools

Other
Total



 246

  76
                                            No.  Above
                                      0.01WL + Background
 0

40
                 No. Between
               0.005WL and 0.01WL
                Above Background
61

12
  Post-remedial

Residences and Schools    217

Other                      35
                     60(e)

                     17
                      51

                       9
(^Modified from reference (CO 79).

(b'Table entries are numbers of buildings having tailings for which
   radon decay product measurements  have been made.

^°'Buildings for which remedial actions have not been completed.
                                   7-15

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                          References  for  Chapter  7

(AE 77)   Atomic Energy  Control Board  of Canada, "Criteria  for Radioactive
         Cleanup in Canada,"  Information  Bulletin 77-2, April 7,  1977.

(CO 79)   Colorado Department  of  Health, October 3,  1979, Letter  from
         A.  Harold Langner, Jr.,  and  subsequent conversations.

(DO 78)   Department of  Energy, Report No.  DOE/EV-0005/3, April 1978.

(FB 76-78)   Ford, Bacon,  and  Davis, Utah,  Inc., "Phase II-Title  1,
            Engineering Assessment  of Inactive Uranium Mill Tailings,"
            20 contract reports  for Department of Energy Contract
            No. E(05-1)-1658,  1976-1978.

(FB 79)   Ford, Bacon, and Davis,  Utah, Inc.,  July 1979, "Engineering
         Evaluation of  the Former Vitro Rare  Metal  Plant,  Canonsburg,
         Pennsylvania"  and "Engineering Evaluation  of the  Pennsylvania
         Railroad Landfill Site,  Burrell  Township,  Pennsylvania."

(FL 78)   Florida Department of Health and Rehabilitative Services,  "Study
         of Radon Daughter Concentrations in  Structures in Polk  and
         Hillsborough Counties," January  1978.

(FR 44)   Federal Register 44.  p  38664-38670,  July 2,  1979.

(GE 78)   George, A.C.,  and Breslin, A.J.,   "The Distribution  of  Ambient
         Radon and Radon Daughters  in Residential Buildings in the New
         Jersey-New York Area,"  presented at  the  Symposium on the Natural
         Radiation in the Environment III,  Houston, Texas, April 1978.

(GJ 79)   Grand Junction Office,  February  1979, "Progress Report  on the
         Grand Junction Uranium  Mill  Tailings Remedial Action Program,"
         U.S. Department of Energy  Report DOE/EV-0033-

(GS Ip)   U.S. Geological Survey, In press,  "Uranium Mill Tailings and the
         Technologically Enhanced Natural Radiation Environment," Circular
         814.

(HE 78)   Healy, J.W., and Rodgers,  J.C.,  October  1978,  "A  Preliminary
         Study of Radium-Contaminated Soils," Las Alamos Scientific
         Laboratory Report No. LA-7391-Ms.

(NC 76)   National Council on  Radiation Protection and Measurements,
         December 1976, "Environmental RAdiation  Measurements,"  NCRP
         Report No. 50.
                                   7-16

-------
(NR 79)   U.S.  Nuclear Regulatory Commission,  April  1979,  "Generic
         Environmental Impact Statement  on  Uranium  Milling,"  Volume  II,
         App.  J,  NUREG-0511.

(PE 70)   Letter by Paul J.  Peterson,  Acting Surgeon General to  Dr. R.L.
         Cleere,  Executive  Director,  Colorado State Department  of Health,
         July  1970.

(PE 77)   Peterson,  Bruce H.,   "Background Working Levels  and  the Remedial
         Action Guidelines,"  in the Proceedings  of  a Radon Workshop,
         Department of Energy Report  No. HASL-325,  July  1977.

(RA 78)   Rahn, P.H.,  and Mabes,  D.L.,  "Seepage from Uranium Tailings Ponds
         and its  Impact on  Ground Water," Proceedings of  the  Seminar on
         Management,  Stabilization, and  Environmental Impact  of Uranium
         Mill  Tailings,  July  1978, the OECD Nuclear Energy Agency.
                                   7-17

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8.  SELECTION OF PROPOSED STANDARDS AMONG ALTERNATIVES








     In PL 95-604, the Congress stated its findings that tailings "...may




pose a potential and significant radiation health hazard to the public,



...and...that every reasonable effort should be made to provide for




stabilization, disposal, and control in a safe and environmentally sound




manner of such tailings in order to prevent or minimize radon diffusion




into the environment and to prevent or minimize other environmental




hazards from such tailings."  The Environmental Protection Agency was




directed by Congress to set "...standards of general application for the



protection of the public health, safety, and the environment..." for such




materials.  The legislative record also shows that Congress intended that




these standards not be site-specific.








     The Committee report on the Uranium Mill Tailings Radiation Control




Act expressed the intention that the technologies used for remedial



actions should not be effective for only a short period of time.  "The




Committee does not want to visit this problem again with additional aid.




The remedial action must be done right the first time," it stated (House




of Representatives Report 95-1480, Part 2).








     Our proposed standards are meant to ensure a long-lasting solution.

-------
8.1  Disposal Standards



     Our analysis of the health effects from tailings piles shows they are




due, in the main, to radon emissions into air.  In addition, environmental




contamination could occur if toxic chemicals from tailings entered surface



or underground water, although this depends strongly on individual site




characteristics.








8.1.1  Radon Standard




     From our analysis of health effects of tailings piles we conclude:








     a.  Radon and its short-lived decay products constitute the dominant




radiation hazard from untreated uranium mill tailings piles on local,




regional, and national scales.  Effects of long-lived radon decay products,



of windblown tailings, and of direct gamma radiation from the piles are




much less significant.








     b.  Individuals near a pile bear much higher radiation risks than




those far away.  For example, we estimate that individuals living




continuously one mile from a large hypothetical pile would have over 200



times as great a chance of fatal lung cancer (7 in 10,000 versus 3 in



1,000,000) caused by radon decay products from the pile as persons living



20 miles away (Table 4-2).  People even closer to some of the piles at




inactive processing sites bear increased lifetime lung cancer risks as




high as 4 chances in 100 (Table 4-1).
                                  8-2

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     c.  The total number of cancer deaths estimated to be induced by a




uranium mill tailings pile depends strongly on the size and distribution




of the local population.








     d.  All the piles taken together may cause about 40 to 90 deaths per




century among persons living 50 miles or more away from a pile.  When




local and regional rates are added to these, the total national effect of




all the piles is estimated as 170-240 premature deaths per century; i.e.,




an annual rate of about 2 deaths.








     These estimates are based upon current population sizes and




geographical distributions.  Overall increases in national population




would raise the estimated national effects in approximate proportion.




Development of new population centers near currently remote piles, and




substantial growth of cities already near one, could multiply local and




regional estimates several fold.








     Unless radon emissions from the tailings piles covered under Title I




of PL 95-604 are greatly reduced, they might prematurely kill about 200




people per century over the indefinite future.  Even for piles now remote



from population centers, equity for people living nearby and the



possibility of future development near the sites argue for control



measures.  A reasonable effort to prevent or minimize radon emissions from



piles is required under PL 95-604.
                                  8-3

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     Methods for controlling radon emissions from tailings piles are


available.   The most straightforward methods involve either burying the


piles or covering them with appropriate combinations and thicknesses of


soils, and  with erosion-resistant surfaces.   We believe the basic capabil-


ities of these methods, although largely untested, are understood.  Other


methods may also be useful, as described in Chapter 5 and Appendix B,  and


in NEC's GEIS for Uranium Milling (NR 79).





     From several perspectives, we find it reasonable to reduce radon


emission rates from tailings at inactive processing sites from their


current values of several hundred pCi/m^-sec to a range more character-


istic of ordinary land.  Typical natural emission rates are from 0.5 to

       p
1 pCi/m -sec, with variations up to several times these values not


unusual (NR 79).





     We considered setting a radon release standard at higher or lower


levels.  Higher levels, say 10-40 pCi/m2-sec, appear unjustified, because


emission rates of that size can be lowered for moderate incremental costs.


With such elevated radon emissions, the probable need for land-use restric-


tions would place a continuing administrative burden on future generations.




     We also find almost total control of radon release from the tailings


unjustified.  Incremental costs for achieving emission rates lower than


1 pCi/m -sec rise rapidly relative to radon emission reduction and any


health benefits that might be achieved.  Land-use restrictions because of
                                  8-4

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radon release are unlikely to be needed for levels near 1  pCi/m^-sec.

We have not found any administrative or esthetic advantages in further

reductions.



     Having decided to control radon emission to a range characteristic of

ordinary land, we next consider the form and numerical values of the

standard.  Three quantities will be considered as the basic unit of the

standard: the radon emission per unit area per unit time ("flux"), the

total radon release rate, or the dose or exposure of actual or

hypothetical individuals or populations.



     A dose or exposure standard is rejected as cumbersome to implement,

with no compensating advantages except its direct relationship to risk.  A

pre-eminent purpose of the standard is to guide the design of disposal

systems.  A dose or exposure standard would introduce avoidable

uncertainty in this process, because flux must be known before these other

quantities can be estimated.



     Limiting the total radon release rate from a site fails to take

account of the great differences in radioactivity among the piles (see

Table 3-4).  Applying a single limit on total radon release to all piles

could place unreasonable burdens on the disposal designs.   A flux limit,
^However, PL 95-604 provides that after remedial actions are
 completed, the tailings will be in Federal custody under license by the
 Nuclear Regulatory Commission.
                                   8-5

-------
however, may readily be applied uniformly to all sites.  Flux is also the

most meaningful quantity for comparing the emission of the site with that

of normal land.  Since radon release rates vary continuously as climate

factors change, however, the standard should address the average flux over

a suitable time (annual).



     We have concluded that the numerical limit on pile flux, following

disposal, should be chosen in a range of about 0.5 to 2.0 pCi/m^-sec.

When added to the flux of a normal earth covering, the disposal site flux

would still be within a normal range.1  The risk for people not directly

on the disposal site is small enough to be a minor factor in choosing a

standard within this range (98% or more of their radon exposure comes from

other sources (NR 79)).



     Disposal sites generally will be large enough to build a small

community upon.  It appears unlikely, however, that a combination of

emission, residency, and construction factors would materialize that would

lead to a public health problem under a standard in the range we are

considering.  The incremental risk associated with the choice of a control

level for radon flux appears small enough so that other factors should

also be considered.
 1A covering of average soil will contribute an additional 0.5 to
 1.0
                                   8-6

-------
     Figure 5-1 shows that, in a flux region near 1  pCi/m -sec, large


increases in covering thickness are needed to further reduce radon emission


when a 99% reduction has already been achieved.  These curves are based on


theory and laboratory tests; there has been no opportunity to test them


against full-scale field experience.  If soil covering should be less effi-


cient in controlling radon than the curves indicate, achieving a standard


at the low end of the radon emission range could be much more difficult


and expensive than we estimate.  Yet, the health benefit so gained would be

                                                                   P
marginal.  We therefore propose an allowed tailings flux of 2 pCi/m -sec


rather than a slightly lower figure to allow for more technical flexibility


in implementing the standard.





     We believe our approach is appropriate for a new and large scale


undertaking.  Typically, the proposed standard would reduce radon emissions


and their effects by 99%-  Measures which will cut down radon emissions


this much for 1000 years (see Section 8.1.5) will also eliminate blown


tailings and excess gamma radiation.  Therefore, implementing the radon


control standard will virtually eliminate all the potential hazards except


water pollution.





8.1.2  Ground Water Standard


     Since most of the inactive sites are in dry climates, much of the


water that may ever infiltrate them has probably already done so during


active operation of the mill.  This probably is not true for all sites,
                                   8-7

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and standards for protecting ground water after disposal of the tailings



are needed.








     The proposed ground water protection standards for uranium mill




tailings are patterned after criteria adopted for solid wastes (FR 79)



under Sec. 1(004 of the Resources Conservation and Recovery Act (RCRA).  EPA




deems violation of these criteria in disposing of the solid wastes to which




they apply to pose a reasonable probability of adverse effects on health or




the environment.  Later, we discuss the possibility of remedial actions for




water contamination that could occur as a result of contaminants released




from tailings prior to disposal.








     Under our proposed ground water standard, tailings may not contaminate



an underground drinking water source beyond a specified distance.  Contam-




ination is defined here as occuring when, after disposal, a tailings pile




causes the concentrations of certain pollutants in the ground water to



either (1) exceed the maximum contaminant level specified for that pollu-




tant, or  (2) increase, where the background concentration of the pollutant




already exceeds the applicable maximum contaminant level.  An underground



drinking water source is an aquifer currently supplying drinking water for




human consumption or an aquifer in which the concentration of total



dissolved solids is less than 10,000 milligrams per liter (FR 79a).








     The  proposed ground water protection standards could be considered too




strict if implementing them would be unreasonably costly, or if they would
                                   8-8

-------
be impossible to apply.  Available information suggests our proposals are




practical.  The following sections discuss alternative approaches to



setting the standard, and describe the reasons for choosing the proposed



standards:








Approach to Ground Water Protection




     These standards are conditions for disposal of uranium mill tailings,




not ambient water quality criteria.  We have concluded that disposal of




tailings should not degrade ground water beyond levels established to




protect human health.  We recognize that ground water quality is important



for other purposes (e.g., for irrigation of plants, for its effect on




fragile ecosystems). Differing standards may be appropriate to protect its




usefulness for these other purposes.  However, at this time, we have




decided to define "contamination" in terms of the water's use as a drinking




water source.  We believe that the prevention of adverse human health




effects from direct consumption of ground water should be the first among



several objectives in protecting ground water quality.  Moreover, EPA has



developed standards for drinking water but has not established standards




for other uses.








     Where maximum contaminant levels in an aquifer are already exceeded,




due to other conditions or actions which do not involve a tailings pile,



tailings disposal should not be allowed to increase the risk to present or




future users of the aquifer.  Future users of the aquifer will not be




protected unless such an approach is taken.
                                   8-9

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Contaminants of Concern



     Contaminant levels in the National Interim Primary Drinking Water




Regulations (NIPDWR) provide the best current guidance of adequate protec-




tion levels for drinking water.  However, we also considered whether all




the appropriate substances in tailings are covered in the NIPDWR, and




whether some contaminants which are covered may be superfluous.








     Except for fluorides, all the inorganic chemicals listed in the NIPDWR




have been reported as present in tailings.  However, uranium mill tailings




are not significant sources of organic chemicals, microbiological



contamination, or man-made radioactivity, so these categories of the




NIPDWR need not apply to tailings disposal.








     Other substances which may be harmful to human health were not included




in the NIPDWR due to their relatively rare occurrence in drinking water




systems, the lack of analytical methods, the high costs of monitoring, or




the lack of toxicity data.  Several such substances are present in leachate




from tailings.  We have reviewed these substances and have included two —




molybdenum and uranium — in our proposed standard, because of the serious-



ness of their toxic effects on humans, animals, or plants, their abundance



in the tailings, and their expected environmental mobility.  The proposed



concentration limit for molybdenum was chosen as appropriate limit for the




protection of human health, in accordance with the recommendations of a




recent report to EPA (CH 79).  The proposed standard for uranium limits the




bone cancer risk to about the same degree as the NIPDWR does for radium.
                                  8-10

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     We have also considered the contaminants addressed by the National




Secondary Drinking Water Regulations (NSDWR).  The NSDWR (40 CFR 143)



represent the Agency's best judgment of the standards necessary to protect




underground drinking water supplies from adverse odor, taste,  color and



other aesthetic changes that would make the water unfit for human consump-




tion.  However, we have decided not to include the contaminants identified




in the NSDWR in the proposed standards.  The list of contaminants we are




including covers the most hazardous substances.  It also covers many




different chemical forms.  Conditions under which these toxic  substances




are well-controlled are likely to also control other substances.  Since we



expect scientific analyses and predictions based upon them to  be the




primary means of demonstrating compliance with the standard, we do not




wish to make that task considerably more complicated by including




nonessential requirements.








     Two other sets of pollutants were considered for inclusion in these




criteria: those covered in the "Quality Criteria for Water" (EP 76) and the




list of toxic pollutants referenced in Section 307(a)(1) of the Clean Water




Act, as amended.  The publication "Quality Criteria for Water" recommends




levels for water quality in accord with the objectives in Section 101(a)



and the requirements of Section 304(a) of the Clean Water Act.  Its primary



purpose is to recommend levels for surface water quality that  will provide



for the protection and propagation of fish and other aquatic life and for




recreation.  Although recommended levels are also presented for domestic
                                  8-11

-------
water supply, and for agricultural and industrial use, ground water was



not a major consideration.








     "Quality Criteria for Water" lists most of the substances in Parts




and 143-  Several of the additional listings are only of interest in




surface water protection, such as definitions of mixing zones, temperature,




and amount of suspended solids.  While several health related substances




that could be present in tailings leachate are listed, the recommended



limits are specified for aquatic life protection and are not appropriate




for ground water.  Furthermore, the recommended limits were written to be




guidance in developing standards, not to be used as standards themselves.




Therefore, we decided that this list was inappropriate for these standards.








Levels of Contamination




     Tailings "contaminate" ground water if they introduce a substance




that would cause:








     (a)  The concentration of that substance in the ground water to




exceed specified maximum contaminant levels, or;








     (b)  An increase in the concentration of that substance in the ground




water where the existing concentration of that substance exceeds the




specified maximum contaminant levels.
                                  8-12

-------
     We intend the first part of the above definition to protect water




that can be used as drinking water without treatment under current




regulations.  The second part is intended to protect ground water already




at or above the maximum contaminant level by preventing increases in




contaminant concentrations.








     We considered several possible reasons for adopting more lenient




standards than the proposed ones: (a) that the increased disposal cost




might be greater than the value of the threatened resource; (b) that the




more efficient approach would be to remove some substances from the water



supply by treatment after contamination; and (c) that some of the allowable




levels are commonly exceeded in ambient or native ground water, which




effectively results in a nondegradation standard for those aquifers.








     There is no doubt that some people will continue to consume ground




water that has not been treated.  That portion of the public, including



those in the future, should be protected from adverse effects caused by




tailings leachate entering their drinking water to at least the extent we




currently protect the general public.  In some situations protecting the



public will require nondegradation of an aquifer.  We are not required to




balance disposal costs against the "value" of ground water resources, nor



can the value of these resources be determined for an indefinite future.



We believe the proposed standards are a reasonable approach to ground




water protection, and that more lenient standards are not preferable.
                                  8-13

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     Reasons we considered for adopting more stringent limits include:



(a) tailings disposal is but one of several sources of ground water contam-



ination, and each source contributes to the overall rise in contaminant




levels; (b) future research may find that lower levels are necessary to




adequately protect health; (c) some agricultural, industrial and other




important uses of ground water may be impaired; (d) since ground water is




often consumed without treatment, more stringent limits would require less




reliance on programs to monitor and to require treatment before domestic




usage.








     The proposed standard does recognize that an aquifer may be polluted




by several sources.  Where existing ground water quality levels exceed the




maximum contamination limits, tailings disposal may not degrade ground



water quality at all.  Based on current knowledge of human toxicity, the



proposed standards are adequately protective.  As discussed earlier, we do




not have the scientific basis for setting stricter standards designed to




protect ground water for all nondrinking purposes.  No matter what the




standard, the need for monitoring must be determined on a case-by-case




basis, and it seems doubtful that differing standards would change that



need.








Where the Standard is Applied




     Another issue regarding ground water protection is where the standard




should be applied (i.e., at what point in the aquifer does contamination




from tailings constitute noncompliance).  The places we considered are at
                                  8-14

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the site boundary, at the waste boundary, or at some specified distance




from the waste.








     In the long-term viewpoint appropriate for uranium tailings, the




concept of a site boundary should play a minor role because it only




distinguishes areas a responsible party controls from areas where the




general public may be affected.  Long after disposal, however, the size of



the region that may be affected is much more significant.








     Applying the standard to the waste boundary would minimize the




affected area.  The tailings at inactive processing sites have to some




extent merged with their immediate surroundings, so the waste boundary may




be hard to define.  More significantly, a standard applied so near the




waste may be difficult to meet at some otherwise adequate, existing sites.




Where only local contamination might occur, the cost of liners and




re-siting appears to be unjustified.  To avoid these higher costs with



their small benefit, a strict standard should apply only beyond some




distance.  We arbitrarily propose this distance to be 1.0 kilometer from




the smallest practical boundary of the waste.  A smaller distance of appli-



cation might not serve the intended purpose of avoiding large expeditures



for very little gain, and we believe a much larger distance would not be



sufficiently protective.  However, if tailings are moved to a new disposal



site, for whatever reason, then new opportunities for site selection and



preparation become available.  For new sites we choose the place of appli-




cation as 0.1 kilometer from the waste boundary.  In effect, this is as
                                  8-15

-------
protective as choosing it at the waste boundary, while allowing some



benefit from sorption and dilution in the ground, in case small leaks




occur.








Underground Drinking Water Source




     The choice of the 10,000 mg/1 total dissolved solids measure for




usable aquifers follows the Agency's general policy that ground water




resources below that concentration be protected for possible use as




drinking water sources.  This policy is based on the Safe Drinking Water




Act and its legislative history, which reflects clear Congressional intent




that aquifers in that class deserve protection.








8.1.3.  Surface Water Protection



     We also have considered the need for surface water protection




standards.  Wind, rain, and floods can carry tailings into rivers, lakes,




and reservoirs.  Pollutants may also seep out of piles and contaminate sur-




face waters.  We believe the standards should limit the effects of these




processes on surface water quality.  We expect that implementing the radon




emission limits and the ground water protection requirements will greatly



reduce contamination of surface water.  A pile with severely restricted



radon releases will not be able to release particulates to wind or water.




Similarly, the ground water protection requirements imply limited water




flow through the pile, which limits flow to the surface as well as under




the ground.  Thus, the radon emission and ground water standards will




provide adequate protection for surface water, and explicit standards may
                                  8-16

-------
not be necessary.  However, to assure adequate protection,  we propose to




require that surface water not be degraded by tailings after disposal of



the piles.  This means that disposal methods should prevent tailings from




increasing the concentration of any substances in surface water.








     We believe it will be practical to satisfy virtually any strict




surface water protection standard.  Because of this, we considered




requiring that there be no releases of pollutants to surface water.



However, this may be more difficult to implement than the selected




standard, since it would require showing that not even microscopic



releases will occur.  Our chosen standard requires any pollutant streams




from the tailings to have lower concentration than the surface water they




may enter.  The standard applies to all pollutants from tailings, however,



and some of them are certainly present only in very low concentrations in




surface water.  Therefore, satisfying the standard will require strict




limits on releases of at least these latter substances.  In practice, we




expect the means used to inhibit pollution of surface water by substances




which are already present in low concentrations to also restrain the




movement of most other pollutants.  Therefore, we expect the standard to




be very protective of surface water.








     We have chosen to apply the standard to "navigable waters" as defined



in an EPA Federal Register notice (44 F.R. 32901, June 7, 1979).  This




definition was adopted for EPA's regulations under the National Pollutant




Discharge Elimination System, 40 CFR 122.3(t).  In essence, it includes
                                  8-17

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all surface waters which the public may traverse,  enter, or draw food from.




However, there is no formal relationship between EPA's standards under




PL 95-604 and regulations under the National Pollutant Discharge




Elimination System; either may be changed without affecting the other.








8.1.4  Remedial Action for Existing Water Contamination




     We have considered whether remedial action standards should be set for




existing and future contamination caused by past releases from the tailings




piles.  We conclude that a general requirement to perform remedial actions




is not feasible, as there are no practical methods which will generally



work.  However, we urge the implementing agencies to study any prospective




contamination, so appropriate restrictions on using water may be




established where they are needed.  We also believe that site-specific




consideration should be given to performing practical remedial actions.




Since there are no generally applicable remedial methods, however, our




standards apply only to contaminants leaving the tailings after disposal



is completed.








8.1.5  Period of Application of Disposal Standards



     The hazards of uranium mill tailings will persist indefinitely.




Through PL 95-604, Congress intended "every reasonable effort" to be made



to provide long-term public protection from these hazards.  Under this



criterion, we propose requiring a reasonable expectation that the radon




emission and water protection standards for disposal will be satisfied for




at least 1000 years.
                                  8-18

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     Any choice of a suitable time period is partly arbitrary, as there



are no rules or precedents to guide the decision.  Neither does scientific




analysis point uniquely to one period over another.








     We have concluded that uranium mill tailings standards which apply for




periods as long as 10,000 to 100,000 years would be impractical.  Providing




reasonable expectation of compliance with the standards over such long




periods, if possible at all for tailings, could be done only if they were




buried several hundred feet or more beneath the surface.  During such long




time periods, climates change markedly and land surfaces may be denuded,



severely uplifted, or otherwise considerably transformed.  Deep below the




surface severe changes are likely to be more gradual and predictable.  For




reasons described earlier, the practicability of deep burial of uranium




tailings is uncertain.  Yet, if strict standards were to apply for as long




as 10,000 years or more, no other disposal method would seem possible.








     With tailings at or near the earth's surface, it appears feasible to




meet the standards for 1000 years or more.  The primary threat during this




period is flooding.  Methods of protecting tailings against floods and



other natural disruptions appear to be available.  However, these methods



may not be applicable at every existing inactive site;  some piles might




have to be moved for long-term flood protection, for example.








     Standards applying for a period shorter than 1000 years would be




easier to satisfy, and might result in some cost savings.  We judge the
                                  8-19

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savings would be small,  unless the period of application were only a few



hundred years.








     The choice of a 1000-year period of application results from



practical considerations.  We believe 1000 years meets the congres-




sional criterion of a reasonable effort to control these materials.  A




1000-year standard does not mean our concern for the future is limited,




but does reflect our judgment that the disposal standards must be




practical.  Technically and economically reasonable disposal methods may,




in some instances, be expected to protect for longer than 1000 years.




However, to generally require this is unreasonable, we believe, based on




existing knowledge of control methods and natural processes.








     The disposal standards could be viewed as performance standards,




stating conditions to be satisfied without addressing the means.  Compli-




ance could be verified by field observations (monitoring), and assured



through maintenance.  More fundamentally, they are design standards.  The




standards are the minimum requirements for the physical performance of a




disposal system over the full period of their application.  Since the




standards apply for at least 1000 years, we believe institutional methods



involving maintenance and monitoring are useful adjuncts to an adequate



disposal system, but they should not replace physical long-term disposal




methods.  The "reasonable expectation" for meeting the limits specified in




the standards will be established by considering the physical properties




of the disposal system,  not by relying on institutional methods.
                                  8-20

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8.2  Cleanup Standards




8.2.1  Open Lands




     The proposed standard requires that for any open land contaminated




with tailings, the average radium concentration in any 5 centimeter



thickness shall not be more than 5 pCi/gm after cleanup.  These conditions




provide a high degree of protection from tailings at inactive uranium




processing sites, and are not unreasonably burdensome to implement.  The




protection achieved will often be greater than is apparent from the




standard, since the radium concentration of any material not removed will




often decrease sharply with depth.  After the required cleanup, such a



site will be little more hazardous than a similar area which never had a




tailings pile.








     Locating contaminated soils with concentrations less than 5 pCi/gm




would require extensive surveys and lengthy measurement procedures.




Increasingly large land areas would need to be stripped in order to lower




the radioactivity much below 5 pCi/gm.  Doing this would provide very




little gain in health protection, since such slightly contaminated soils




are usually thin layers containing little total radium.  Therefore, in




order to keep sampling costs within reason, and to avoid having to clean



large areas which contain little radioactivity, the proposed final




standard requires that for any open land contaminated with tailings, the



average radium concentration shall not be more than 5 pCi/gm after




cleanup.  The contamination which remains after such cleanup will have




less than 5 times the radon release of average soils.  It could also cause
                                  8-21

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a gamma radiation dose of less than 80 millirad per year to a person who



spends 100 percent of the time outdoors on the site.  These levels of



radon emission and gamma radiation are within the variations that occur in




undisturbed land areas.  We believe that the actual radon and gamma ray




levels after cleanup will usually be much less than the maximum possible




under these standards.








     For contaminated material located more than 1 foot beneath the surface




of open land, our proposed standard requires cleanup if the average radium




concentration over any 15 cm thickness is greater than 5 pCi/gm.  Practical



measurement instruments could not find buried material of this concentra-




tion in any thinner layer.  We expect this standard for buried material




will mostly apply to defining the edges of buried tailings deposits,




because the radium concentration in tailings is usually much higher than




5 pCi/gm.








     In most cases, concentrations a few times higher than the proposed




standard allows would cause only a slight increase in risk.  Since concen-




tration usually declines rapidly with depth, even a standard requiring



removal of material until the radium concentration level reached 10 or



20 pCi/gm would be protective.  Unusual distributions of radium would be



much more significant, however, and areas with 5-20 pCi/gm are clearly




above ordinary background levels.
                                  8-22

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     Surveys at inactive processing sites indicate that it should cost




little more to implement the proposed standard than one permitting levels




2 to 4 times higher.  The proposed standard is EPA's judgment of the most




stringent cleanup condition that may reasonably be required uniformly for



all the inactive mill sites.








     The proposed standard addresses future as well as present hazards and




uses an intrinsic property of tailings that can be easily measured.  We




considered other forms for the standard, such as limiting the residual




surface gamma radiation, the radon release rate, or the predicted



concentration of radon decay products in future buildings on the land.




All these would restrict the residual hazard, but they would be harder to




apply to material which has been buried, but might be uncovered later.








     We expect that the rules developed to implement this standard will




relate the concentration of radium in soil to other conveniently measured



quantities.  We also expect that appropriate sampling techniques will be




established to locate and identify tailings material, to determine its




concentration of radium, and to verify compliance with the standard.  Any




such rules must insure that the standard is not met simply by dispersing



the material to achieve a lower concentration.
                                  8-23

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8.2.2  Buildings



8.2.2.1  Justification for the Proposed Indoor Radon Decay Product



         Concentration Standards




     Exposure to even normal indoor radon decay product concentrations




carries some health risk, but we believe Congress intended that people




should not have to bear an unreasonable increase in this risk due to




tailings.  Remedial action will be required when a building affected by




tailings exceeds the levels we set as the remedial action standards.  When



remedial actions are finished, the level must either not be exceeded, or




else tailings must not be the cause of any remaining excess.  We believe



that expressing the indoor radon decay product standard in terms of total




concentration of these products is the only workable form, as the




following discussion indicates.








     Indoor radon decay product concentrations of normal buildings vary




widely.  Tailings near or under a building may be identified by gamma ray



measurements, historical records, visual inspections, or specimen analysis.




However, because of the fluctuations in normal indoor radon levels, it is




impossible to tell what the concentration of radon decay products would be



without the tailings.  Small elevations when tailings are present cannot be



distinguished from normal background levels.  Furthermore, contaminated



buildings vary in location, design, materials, and patterns of use, all of




which affect the indoor radon decay product concentration.  Therefore, it




is neither practical to determine an expected background value for a
                                  8-24

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particular building from measurements of unaffected buildings, nor by any



other means.








     For the above reasons, an action level expressed in terms of an




increment over the background radon decay product concentration could not




be implemented easily.  We prefer an action level in terms of the total




indoor concentration, which is directly measurable.  With a fixed




measurement method, this standard gives an unambiguous decision of




eligibility for remedial action for any building affected by tailings.








     We also considered expressing the standard in terms of the quantity




or concentration of tailings near the building, or the gamma radiation




they produce.  However, there is no sure way to relate these quantities to




indoor radon decay product concentrations.  This is a critical deficiency,




because the radon products are the basic hazard.








     A standard for total concentration of radon decay products provides




the same action level for all affected buildings, regardless of whether




normal concentrations in one affected area may tend to be higher than in



another.  While normal indoor radon decay product concentrations vary with




natural radium concentrations in soil, soil porosity, and other factors,



we know of no way to take them into account in the standard.  In these



circumstances, we consider the regional protection inequity minor, as long




as the action level we choose is within the normal range of levels in the




affected areas.
                                  8-25

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     We believe that the proposed remedial action level of 0.015 WL

(including background) for occupied or occupiable buildings is the most

protective level that can be justified for the PL 95-604 remedial action

program.  It is about the same as that applied to homes and schools over

the last seven years in the Grand Junction remedial action program,

because the action level there was 0.01 above an "average" background

value taken as 0.007 WL.  Experience in the Grand Junction program and

studies performed by EPA for homes in Florida (without basements) indicate

that remedying concentrations greater than 0.015 WL is usually practical

in view of technical and cost considerations.  In some situations, a lower

action level might be justified.  However, studies of normal houses with

basements in Grand Junction, New York, and New Jersey indicate that about

10 percent or more are above 0.015 WL.  We have concluded that efforts to

reduce levels significantly below 0.015 WL by removing tailings would

often be unfruitful, and the funds expended wasted.



     Although indoor radon decay product levels exceeding 0.015 WL can

occur without the presence of uranium mill tailings, these proposed

standards are explicitly for remedial actions at sites designated under

PL 95-604.1  PL 95-604 is clearly directed at potential health problems

due to tailings, and not to similar hazards from other causes.  It is not

our intention for there to be lengthy and expensive procedures to determine
1In particular, the proposed remedial action standard should not
necessarily be taken as an appropriate design goal for indoor radon
decay product concentration in new housing.
                                  8-26

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whether any tailings are present when the level is only slightly exceeded.

Professional judgment in the field must be relied upon in such cases for

sensible implementation of the standards.  If the allowable level is still

exceeded after all apparent tailings have been removed or otherwise

prevented from affecting the interior of the building, then the standard

would not require further remedial measures.



8.2.2.2  Standards for Indoor Gamma Radiation

     The proposed limit on indoor radon decay product concentration is

based on the hazard from breathing air containing these products.  Tailings

also emit gamma radiation, however, which can penetrate the body from the

outside.  We expect the indoor radon decay product concentration standards

generally will be met by removing of the tailings from the building, and

this will eliminate any indoor gamma radiation problem.  It is only in

unusual cases that a standard for limiting gamma radiation exposure may be

needed.



     It will often be possible to meet the radon decay product standards

without removing the tailings.  Removal is the remedial method we wish

most to encourage, however, because of its positive and long lasting

effectiveness.  To this end, we propose an action level for gamma

radiation of 0.02 mR/hr above background,1 which allows a limited degree
 Indoor background levels of gamma radiation are easier to determine
and less variable than is the case for measurements of radon decay
product concentration.
                                  8-27

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of flexibility in the methods for reducing indoor radon decay product



concentrations.  On the other hand, reducing the standard much below



0.02 mR/hr would virtually eliminate flexibility in remedial methods, and




provide only a small additional health benefit to those few individuals




who might be affected.  Assuming the occupants of the building to be




present 75 percent of the time, the proposed standard would allow gamma




radiation doses from the tailings of about 130 mrad per year.  This is




about twice the average annual background dose from gamma rays in the




regions near the piles.








8.2.2.3  Radiation Hazards not Associated with Radium-226




     The total protection provided by a standard based on radium-226




depends on the extent to which radium has been separated from other



radioactive substances during ore processing.  Radium-226 concentrations




in the residual material may not be an adequate measure of the radiation




hazard in all cases.




     For the reasons discussed in Sec. 7.3, we are not yet able to say in




all cases how effective cleanup standards based on radium-226 will be in




controlling U-235 decay products and thorium, and we are not in a position



to set a separate standard for them.  It is our judgment, however, that



adequate protection would be provided if, after cleanup, the total risk



from all uranium and thorium isotopes and their decay products posed no



greater risk than the proposed final cleanup standards allow for




radium-226 and its decay products.  The degree to which any particular
                                  8-28

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site would need to be cleaned in order to meet this condition will have to




be determined following detailed studies of its tailings, and further




evaluation of the hazard pathways.
                                  8-29

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                          References  for  Chapter  8

(AE 77)    Atomic  Energy Control Board (of Canada),  April  7,  1977,
          "Criteria For Radioactive Clean-up in Canada,"  Information
          Bulletin 77-2.

(CH 79)    Chappell, W.H.,  et al..,  1979,"  Human Health  Effects  of
          Molydbenum in Drinking Water,"  USEPA Health  Effects  Research
          Laboratory Report, EPA-600/1/79-006.

(EP 76)    U.S.  Environmental Protection Agency, 1976,  "Quality Criteria
          for Water," Report EPA-440/9-76-023.

(EP 78)    U.S.  Environmental Protection Agency, June 1978,  "State  of
          Geological Knowledge Regarding  Potential  Transport of High-Level
          Radioactive Waste From Deep Continental Repositories," Report
          EPA/520/4-78-004.

(FB 76-78)  Ford,  Bacon,  and Davis, Utah,  Inc., "Phase II-Title 1,
            Engineering Assessment of Inactive Uranium Mill  Tailings"
            20  contract reports for Department of Energy  Contract
            No. E(05-D-1658,  1976-1978.

(FR 79)    Federal Register 44. p 53438-53468, September 13,  1979;
          40 CFR Part 257.

(FR 79a)   Federal Register 44. p 23738-23767, April 20, 1979.

(GJ 79)    Grand Junction Office, February 1979, "Progress Report on the
          Grand Junction Uranium Mill Tailings Remedial Action Program,"
          U.S.  Department of Energy Report DOE/EV-0033-

(GS 78)    U.S.  Geological Survey,  1978, "Geologic Disposal of  High-Level
          Radioactive Wastes — Earth-Science Perspectives," Circular 779.

(HE 78)    Healy,  J.W.,  and Rodgers, J.C.,  October 1978, "A Preliminary
          Study of Radium-Contaminated Solid," Los  Alamos Scientific
          Laboratory Report LA-7391-MS.

(NE 78)    Nelson,  John D., and Shepherd,  Thomas A., April 1978,
          "Evaluation of Long-Term Stability of Uranium Mill Tailing
          Disposal Alternatives,"  Civil Engineering Department,  Colorado
          State University prepared for Argonne National  Laboratory.

(NR 79)    U.S.  Nuclear Regulatory  Commission, April 1979, "Draft
          Generic Environmental Impact Statement  on Uranium Milling,"
          NUREG-0511.

(PE 70)    Letter by Paul J. Peterson, Acting Surgeon General to
          Dr. R.L. Cleere, Executive  Director, Colorado State  Department
          of Health,  July 1970.


                                  8-30

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9.  IMPLEMENTATION








9-1  Administrative Process




     Public Law 95-604 requires that EPA's standards for uranium mill




tailings from inactive processing sites be implemented by the Secretary of




the Department of Energy (DOE).  The Secretary or a designee will select




and perform remedial actions for designated processing sites in accordance




with the standards, with the full participation of any State which shares




the cost.  Selection and performance of the remedial actions will be with




the concurrence of the Nuclear Regulatory Commission and in consultation,




as appropriate, with affected Indian tribes and the Secretary of the




Interior.  The costs of the remedial actions will be borne by the Federal




government and the States as prescribed by law.









9.1.1  Disposal Standards




     The disposal standards will be implemented by showing that the




disposal method provides a reasonable expectation of satisfying the radon




emmission limits and water protection provisions of the standard for at




least 1000 years.  We intend for this expectation to be founded upon




analyses of the physical properties of the disposal system and the




potential effects of natural processes over time.  Computational models,




theories, and expert judgment will be major tools in deciding that a




proposed disposal system will satisfy the standard.  Post-disposal




monitoring can serve only a minor role in confirming that the standards




are satisfied.  It is not reasonabe to expect that any violations

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discovered hundreds of years from now will be remedied under the authority




of PL 95-604.  The disposal standards must be satisfied in the current era




by methods that provide a reasonable expectation of continued




effectiveness over the required period.








9.1.2  Cleanup Standards




     Subsequent to making a radiation survey of open lands and buildings in




areas believed to have tailings, DOE must determine whether or not tailings




are causing the standards to be exceeded.  After performing necessary




remedial actions to reduce radiation levels, it will be necessary to verify



compliance with the standards.  To conduct these activities, DOE, working




with NRG, will need to develop radiological survey, sampling, and measure-




ment procedures to determine necessary and practical cleanup actions, and




to certify the results of the cleanup.  We have published elsewhere the




general requirements for an adequate land cleanup survey (EP 78a).








     These procedures are significant elements in determining the effec-



tiveness of the standards.  In view of this, we considered providing more




details of the implementation as part of our rulemaking.  We chose not to




do so in order to give more flexibility to the implementers.  We believe



this is warranted because of widely varying and incompletely known




conditions among and within the various processing sites.  However, the



following clarification of our intentions should help to avoid unproductive




use of resources.  This could result if the standards were interpreted so




strictly that demonstrating compliance would be unreasonably burdensome.
                                    9-2

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     The purpose of our standards is to protect public health and the




environment.  We designed them to be adequately protective using search



and verification procedures whose cost and technical requirements are




reasonable.  For example, since we intend the cleanup standards for



buildings to protect people, measurements in such locations as crawl



spaces and furnace rooms are inappropriate.  Remedial action decisions




should be based on radiation levels in occupiable parts of the buildings.




The standards for cleanup of land surfaces are designed to limit exposures




of people to gamma radiation, and to radon decay products in future




buildings.  In most circumstances, failure to clean a few square feet of




land contaminated by tailings would be insignificant.  Similarly, in



attempting to find tailings which are below the surface on open land,




reasonableness must prevail in determining where and how deeply to search.




It would be unreasonable to require proof that all the tailings had been




found.  In all applications of our proposed cleanup standards, search and




verification procedures which provide a reasonable assurance of compliance




with the standards will be adequate.  We are confident that DOE and NEC,




in consultation with EPA, will adopt specific implementation procedures




which apply most of the resources to reducing radiation exposures, and



will minimize the resources needed for surveys.
                                    9-3

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9.2  Exceptions



     We believe that our proposed standards are the strictest that are




justified for general application at all the inactive uranium processing




sites covered by PL 95-604.  However, providing greater protection may be



reasonable at specific sites.  Therefore, we urge the implementers to




lower the residual risk as far as reasonably achievable, within the limits




set by the standards.








     In the decades since tailings at inactive sites were deposited,




weather and people have created a wide range of problems needing remedi-




ation.  There may be exceptional circumstances for which the standards are




unreasonably strict.  If it is impossible to meet the standards, or if some




clearly undesirable health or environmental side-effects are unavoidable,




applying the standards would not be justified.  For example, when tailings




are not accessible to the equipment needed for their removal, or where




workers might be endangered in trying to remove them, application of the




standards should be reconsidered.  Similarly, distrubing scarce desert




vegetation and soils may not be justified where the standards are only




slightly exceeded.








     We do not consider cost a reason for noncompliance unless the cost to




comply is very high or the benefit is very small.  For example, it may not




make sense to spend a great deal of money to clean up an infrequently




occupied building where the standards are only slightly exceeded.








     In order to allow for reasonable implementation of PL 95-604 in all




of the varied circumstances, we are proposing criteria which the




implementers may use to determine whether particular circumstances are






                                    9-4

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exceptional.  In such exceptional cases,  DOE may select and perform




remedial actions which come as close to meeting the standards as is



reasonable.  In the selection of such remedial actions, DOE shall ask any




property owners and occupants for their comments,  the concurrence of NRC



shall be required,  and DOE shall inform EPA.
                                    9-5

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9.3  The Effects of Implementing the Standards








9.3-1  Health




     The proposed standards reduce average radon emissions of the tailings



piles more than 99% for one thousand years.  If the current rate of lung




cancer deaths would otherwise have persisted,  then we estimate applying




the standards will avoid about 2000 premature lung cancer deaths.








     Some people now living very near tailings piles could bear a risk of




premature death due to lung cancer of several chances in 100.  Under the




disposal standards, people living in comparable locations during the next




1000 years will bear much lower risk from the pile, about 1 chance in



10,000.








     After remedial actions are completed on buildings eligible under




PL 95-604, their occupants will be subject to radon decay product




concentrations less than 0.015 WL (including background), and gamma



radiation exposure rates lower than 0.02 mR/hr.  Their estimated total




risk of fatal cancer due to residual tailings following remedial action



will average less than about 1/&.  This is within a normal range of



fluctuation for risk due to indoor radon decay products alone in the




absence of tailings.








     After remedial actions are carried out on eligible open land,




residual contaminated materials will have less than 5 times the radon
                                    9-6

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release of average soils.  It could also cause a gamma radiation dose of




less than 80 millirad per year to a person who spends 100 percent of the



time outdoors on the site.  These levels of radon emission and gamma




radiation are within the variations that occur in undisturbed land areas.



We believe that the actual radon and gamma ray levels after cleanup will




usually be much less than the maximum possible under these standards.




radium-226, almost certainly distributed in a thin layer.  Gamma radiation




from a 5 centimeter thickness of residual soil having the maximum allowable




concentration under the standard could produce about 2 chances in 1000 of




fatal cancer for a person exposed outdoors continuously over a lifetime.



Actual exposures will be much lower.  The gamma radiation increment over



the affected region would be within a normal range of fluctuation among




similar regions which are unaffected by tailings.








9.3.2  Environmental




     Tailings will be controlled for at least 1000 years under the proposed




standards, so dispersal by floods, erosion, or mass movement should not



occur during that period.  Releases of radon gas to the air from the site




will be slightly above average, but within a normal range.  High quality



ground water will be protected for a wide range of uses, including



drinking; lower quality ground water will not be degraded by the tailings.








     Contaminated open land will be subjected to scraping and digging by




the cleanup operations.  Generally these activities will occur immediately




adjacent to the piles, but off-site areas where tailings had been purpose-
                                    9-7

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fully used will also be affected.   Disposal operations may require large




quantities of clay and soil for covering the tailings (depending on the



disposal method).   The environmental effects of obtaining these materials




will vary with the site.  The general ecological effects of land cleanup



and restoration operations are examined in detail in an EPA report




(EP ?8b).








9.3.3  Economic




     The total cost of disposing of all the tailings piles eligible under




PL 95-604 is difficult to estimate, primarily because methods will be




chosen site-specifically.  We estimated the cost of covering an average




pile to meet the proposed radon emission standard as $1-6 million if the




existing site is suitable, or $6-13 million for a new location.  Therefore,




the total disposal cost for all sites would be $21-273 million.  Deep




burial and chemical treatments could be considerably more expensive.








     Cleanup costs for open land and buildings have been estimated using



interim cleanup criteria as about $10 million (see Section 7.4).  Even




allowing for increased costs under the proposed standards, tailings



disposal is still by far the largest cost component of the remedial action



program.








     Although difficult to estimate, the total cost of the entire program




probably will be $200-300 million.  These costs will be shared by the




Federal Government (90%) and any State government (10%) in which an
                                    9-8

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inactive processing site is located.  We expect the expenditures will be




spread over the seven-year authorization of the program.  Most of these



expenditures will occur in the regions the tailings are located.  Their




significance depends on the amount expended,  the size of the local



economy, and the availability of necessary equipment and labor.








     Contaminated land and buildings may be made available for use as a




result of the cleanup program.  Balancing this, when tailings are




relocated, is the removal of the new disposal site from other potential




uses.








     In summary, the program could result in net economic benefits of




decreased unemployment and increased business activity for the regions the




piles are located.  We expect little or no perceptible national economic




impact because the total seven-year expenditures will be small compared to




the annual Federal budget (less than 0.06$ of 1978 budget), the annual




Gross National Product (less then 0.01$ of 1978 GNP), and the construction




industry (less than Q.5% of 1978 billings).
                                    9-9

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9.4  The Proposed Standards




     The proposed standards are presented in Appendix C,
                                    9-10

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                          References  for  Chapter  9








(EP 78a)  "Response to Comments:  Guidance  on  Dose  Limits  for  Persons




         Exposed to Transuranium Elements in the  General Environment," EPA



         Technical Report  520/4-78-010.








(EP 78b)  "The Ecological Impact  of Land Restoration and  Cleanup,"




         August 1978,  EPA  Technical Report 520/3-78-006.
                                   9-11

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APPENDIX A
 Comments

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          APPENDIX  B
Development of Cost Estimates

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                                APPENDIX B
                       Development of Cost Estimates
B.1  The Average Inactive Uranium Mill Tailings Pile
B.2  Development of Unit Cost Computations	     4
     B.2.1  Earth Work	     4
     B.2.2  Caps and Liners	     8
     B.2.3  Stabilization 	     9
     B.2.4  Fencing	    11
     B.2.5  Irrigation	    12
     B.2.6  Matrix Fixation	    12
     B.2.7  Tailings Transportation 	    13
     B.2.8  Discount Rate	    16
     B.2.9  Present Worth of Future Costs 	    16
     B.2.10 Land Costs	    17

B.3  Cost Estimates For Disposal Options	    18
     B.3-1  Option 1 - No Radon Control	    18
     B.3.1.1  Option 1a - Fencing	    18
     B.3.1.2  Option 1b - Stabilization With No Radon Control .  .    19
     B.3.2  Controlling Radon Emissions with an Overburden  ...    22
     8.3.3  Option 2 - Existing Surface Site,  Covered
              to Control Radon Emissions  	    22
     B.3.3.1  Dimensions  	    24
     B.3.3.2  Cost Estimates  	    26
     B.3-3.3  Use of Tables B-7 Through B-11	    32
     B.3.4  Option 3 - New Site, Below Grade,  with Liner if
              Needed	    34
     B.3.4.1  Requirements	    34
     8.3.4.2  Dimensions and Cost Estimates 	    36

B.4  Other Disposal Methods 	    44
     B.4.1  Extraction and Disposal of Hazardous Materials  ...    44
     B.4.2  Long-Term Radon and Hydrology Control 	    49

References for Appendix 8	    54

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                                  FIGURE

                                                                    Page

B-1   Cross-Section of the "Average" Mill Tailings Pile	    3


                                  TABLES

                                                                    Page

B-1   Unit Costs	5,6
B-2   Estimated Capital Costs of Matrix Fixation  	   14
B-3   Annual Operating Costs for Matrix Fixation  	   15
B-4   Costs and Dimensions of Particulate Control 	   21
B-5   Thickness (meters) of Cover Required to Reduce Radon to
        Control Level 	   23
B-6   Control Methods for Disposal Option 2 	   25
B-7   Costs and Dimensions for Disposal Option 2 with Control
        of Radon to 100 pCi/m2/sec	   27
B-8   Costs and Dimensions for Disposal Option 2 with Control
        of Radon to 10 pCi/m2/sec	   28
B-9   Costs and Dimensions for Disposal Option 2 with Control
        of Radon to 5 pCi/m2/sec	   29
B-10  Costs and Dimensions for Disposal Option 2 with Control
        of Radon to 2 pCi/m2/sec	   30
B-11  Costs and Dimensions for Disposal Option 2 with Control
        of Radon to 0.5 pCi/m2/sec	   31
B-12  Control Methods for Disposal Option 3 	   35
B-13  Constant Costs for Below-Grade Disposal of Uranium Mill
        Tailings	   37
B-14  Variable Costs and Dimensions for Disposal Option 3 with
        Control of Radon to 100 pCi/m2/sec	   39
B-15  Variable Costs and Dimensions for Disposal Option 3 with
        Control of Radon to 10 pCi/m2/sec	   40
B-16  Variable Costs and Dimensions for Disposal Option 3 with
        Control of Radon to 5 pCi/m2/sec	   41
B-17  Variable Costs and Dimensions for Disposal Option 3 with
        Control of Radon to 2 pCi/m2/sec	   42
B-18  Variable Costs and Dimensions for Disposal Option 3 with
        Control of Radon to 0.5 pCi/m2/sec	   43
B-19  Costs of Nitric Acid Leachate Disposal  	   47
B-20  Costs of Residual Tailings Disposal 	   50
B-21  Cost Estimates of Deep Disposal When a Nearby Open-pit
        Mine is Available	   52
B-22  Cost Estimates of Deep Disposal When a Nearby Underground
        Mine is Available	   53

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                                APPENDIX  B




                       Development of Cost Estimates








B.1  The Average Inactive Uranium Mill Tailings Pile




     For the purpose of developing cost estimates of the various uranium




mill tailings disposal methods, we employed an "average" inactive uranium




mill tailings pile, with dimensions based upon the average dimensions




found at the 21 inactive uranium mill tailings sites.  The tailings area,




volume, and weight dimensions have been computed from the information




found in the Ford, Bacon and Davis, Utah,  Inc, engineering reports on the




inactive uranium mill tailings sites (FB 76-?8).








     The "average" pile has the configuration of s. truncated regular pyra-




mid with a lower base of 436m on a side including embankments.  Figure 3-1




gives a cross section of the uranium mill tailings impoundment area.  The




mill tailings pile covers a surface area of a little more than 19 hectares




(190,000m2, or 47 acres).  The embankments contain 784,000m3




(1,026,000 yd3) of uranium mill tailings that weigh 1,325,000 short




tons, and the tailings are assumed to be 5.0m deep within the embankments.




Furthermore, it is assumed that when the uranium milling operations had



ceased at the location, the tailings pile was left flat on top but




uncovered, and there is evidence of both wind and water erosion.  Tests



indicate that tailings have migrated as far as 1000m from the average




tailings pile.
                                   B-2

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B.2  Development of Unit Cost Computations




     The unit costs used for estimating the costs of the disposal options



are presented in Table B-1.  They are average costs and represent the



expected monetary values that will be encountered while completing indi-




vidual tasks, or purchasing specific items necessary for the various




uranium mill tailings disposal methods considered in this report.  The




unit costs are evaluated in 1978 dollars and reflect the economic




conditions of that year.








     The procedures used to derive the unit costs are as follows:








          a. Any costs not already evaluated in 1978 dollars, are adjusted




to reflect 1978 values using an appropriate price index (usually the U.S.



Department of Commerce Composite Construction Cost Index published in the




Survey of Current Business).




          b. When only one source for the cost of an item is available,




that value is used.
          c. When more than one cost estimate is available, the average




of these values is used.








B.2.1  Earth Work




     The sources for computing the costs for various types of earth work



are Dodge (DO 78), Means (RA 77), and the NRC-DGEIS (NR 79).
                                   B-4

-------
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                                 TABLE B-1

                                 Unit  Costs


     Task                                             Cost (1978 dollars)

1.    Earth work

     a.  Below grade excavation in normal soil             $1.63/m3
         Below grade excavation in shale                   $3.10/m3
     b.  Dragline excavation and loading                   $1.53/m3
     c.  Excavate,  load, and haul                          $1.13/m3
     d.  Spread and compact                                $0.38/m3
     e.  Haul, dump, spread, and compact                   $1.33/m3

2.    Caps and Liners

     a.  Clay when available                               $2.07/m3
     b.  Clay when purchase is required                    $5.00/m3
     c.  Synthetic                                         $4.4l/m2
     d.  Asphalt emulsion (1/2" thick)                     $1.76/m2

3-    Stabilization

     a.  Vegatation when soil is available                 $0.75/m2
     b.  Vegatation when soil purchase is required         $2.51/m2
     c.  Rip rap (.5m thick)                              $12.90/m2
     d.  Gravel (.5m thick)                                $2.57/m2
     e.  Chemical                                          $0.7*1/m2

4.    Fencing

     a.  5-6 foot high chain link fence                    $29.69/m
     b.  Security fence (prison grade)                     $84.51/m

5.    Irrigation

     a.  Equipment (excluding pumps)                  $1070/hectare
     b.  Annual operating costs                       $273/hectare
     c.  Submersible pump                             $1000 each
                                   B-5

-------
                                TABLE B-1                      (continued)

                                Unit Costs


     Task                                             Cost (1978 dollars)

6.   Matrix Fixation

     a.  Cement with thermal evaporator
           capital costs                                   $4,750,000
           annual operating costs                          $6,575,000
     b.  Cement with filter bed
           capital costs                                   $6,550,000
           annual operating costs                          $2,140,000
     c.  Asphalt with thermal evaporator
           capital costs                                   $7,900,000
           annual operating costs                          $8,515,000
     d.  Asphalt with filter bed
           capital costs                                   $9,700,000
           annual operating costs                          $4,070,000

7.   Tailings Transportation

     a.  Truck                                         $0.10/ton-mile
     b.  Rail                                          $0.08/ton-mile
     c.  Pipeline (7" diameter)
         capital equipment and right-of-way              $63,840/mile
         operating costs                              $0.048/ton-mile

8.   Discount rate (real rate of return)                      7%

9.   Future Costs

     a.  Vegetation stabilization
           Annual operating cost                       $3,900/hectare
           Irrigation equipment                          $400/hectare
           Submersible pump                               $2,500 each
     b.  Chemical stabilization                       $23,800/hectare
     c.  5-6 foot high chain link fence                       $4.27/m
     d.  Security fence (prison grade)                        $12.17/m

10.  Land Costs (farmland)                               $781/hectare
                                   B-6

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     There are two types of below-grade excavation depending on the




consistency of the material being excavated (i.e., normal and shale).



Although classified as one category, normal below-grade excavation is not




homogeneous; it includes digging in soft soil as well as various forms of



clay.  Similarily, the costs of excavating in such a variety of soil types




can vary significantly.  As a result, the expected cost for normal below




grade excavation is $1.63/m3, but may actually range anywhere between




$0.56/m3 and $5.98/m3.  On the other hand, when excavating shale, the




cost for below-grade excavation rises to $3.10/m3, on the average, and




may range between $2.56/m^ and $3-8l/m3.








     According to Ford, Bacon and Davis, Utah, Inc. (FB 76-?8), a dragline




method of tailings excavation is required to remove the uranium mill




tailings from their present site.  This method of tailings excavation is




assumed throughout this report.  Estimates of dragline excavation and




loading establish the cost for removing the uranium mill tailings at



$1.53/m3.








     Excavation, loading, and hauling (up to one mile) of surface soil is



expected to cost $1.13/m^, but may be as low as $0.92/m3 or as high



as $1.58/m3.  Spreading and compacting materials (such as mill tailings,




top soil, clay, etc.) will average $0.38/m^, but may range between



$0.22/m3 and $0.75/m3.  Finally, hauling (up to one mile), dumping,




spreading, and compacting is expected to cost $1.33/m^ and is considered




to be a single task.
                                   B-7

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B.2.2  Caps and Liners




     The sources for unit cost estimates of caps and liners are Dames and



Moore (DA 77), the NRC-DGEIS (NR 79), and Smith and Lambert (SM 78).








     There are basically three types of caps and liners; clay, synthetic,




and asphaltic emulsion.  The major purpose of a cap is to reduce radon




emissions from the mill tailings into the surface environment.  Some




hydrologic control is also afforded by a cap because it reduces seepage




of surface water into the tailings.  On the other hand, liners are used




chiefly to provide hydrologic control beneath the pile.  That is, a liner




will reduce moisture seepage from the mill tailings into the ground water



or ground water infiltration into the tailings.








     Assuming a nearby source of suitable clay (i.e., a clay having a




large proportion of montmorillonite) is available at no cost, a clay cap




or liner can be expected to cost $2.07/m^ to install, but may actually




range between $1.l4/m3 and $2.93/m3.  If a suitable type of clay must




be purchased, an additional $2.93/m3 should be added to the cost of




installing a clay cap or liner.








     Many types of synthetic materials are available which could be used




as a cap or liner for uranium mill tailings (e.g.,  polyster reinforced



Hypolon or Polyvinylchloride).  Because these types of caps and liner




require a carefully prepared installation, they can be quite expensive.
                                  B-8

-------
On the average, $4.4l/m2 is the expected cost of installing a synthetic


cap or liner, but the cost may range between $2.00/m2 and $11.89/m2.




     The least expensive method of providing a cap or liner for uranium


mill tailings appears to be an asphaltic emulsion.  Smith and Lambert


(SM 78) estimate that the cost of applying a 0.5 inch thick layer of

                                                  f}
asphaltic emulsion costs $7,1^0 an acre or $1.76/m .




B.2.3  Stabilization


     All methods of stabilizing uranium mill tailings disposal sites have


a common purpose; that is, to provide wind and water erosion protection.


This reduces the quantity of uranium mill tailings that migrate from the


disposal site.  Four methods of stabilization are considered in this


report: vegetation, rip rap, gravel, and chemical.




          a.  Vegetation used as a stabilizer consists of plant growth


which holds the surface in place.  The proper installation of vegetation


requires approximately eight inches of suitable surface soil to insure


plant propagation.  Besides seeding, fertilizer, lime, and soil binders


are also necessary to aid plant growth until a ground cover is


established.  If it is assumed that a suitable type of top soil is


locally available, the cost of providing a cover of vegetation will cost


$0.75/m2, but may range between $0.38/m2 and $1.12/m2.  If top soil


and loam must be purchased, then the cost of vegetation becomes
                                   B-9

-------
significantly more expensive (i.e., the average cost will be $2.51/nr


and range between $1.48/m2 and $3-93/ni^).  These cost estimates do


not include the cost of irrigation for those areas where adequate


precipitation to maintain vegetation is not available.  The capital and


operating expenditures associated with irrigation are discussed later.




          b.  Rip rap consists of large stone or concrete chips (1/4 to


3/8 yd3 in size) in a layer approximately 0.5m thick as a cover on the


uranium mill tailings disposal site.  Rip rap is either placed loose or


enclosed in galvanized steel mesh boxes called gabions.  Rip rap has an


average installation cost of $12.90/m^.  If placed loose, rip rap can


cost as little as $4.?8/m2.  But if the rip rap must be enclosed in


gabions, the cost of providing a rip rap cover may be as high as


$25.79/m2.




          c.  Like rip rap, gravel provides wind and water erosion protec-


tion for the uranium mill tailings disposal site, and an 0.5m thick cover


of gravel is assumed to be required for adequate wind and water erosion

                                                               fy
protection.  Installing a 0.5m thick gravel cover costs $2.57/m , on


average, but ranges between $2.49/m^ and $2.73/m .




          d.  Other types of covers, categorized here as chemical


stabilizers, include asphalt, asphaltic emulsion, road oil, and various


other chemicals.  Although the chemical stabilizers appear to be the


least expensive method of stabilizing a uranium mill tailings disposal
                                  8-10

-------
site (i.e., average cost of installation is $0.75/m2), the cost of




application has a wide range (between $0.05/m2 and $9.69/m2).




Furthermore, their long-term stability is untested.  Some methods require




replacement in less than a year while others may last as long as twenty




years or more.  For cost estimation, it is assumed that a chemical



stabilizer will need replacement very four years.








B.2.1*  Fencing




     Sources for unit costs of fencing are Dodge (DO 78), Means (ME 77),




the NRC-DGEIS (NR 79), and Smith and Lambert (SM 78).








     Isolation of the uranium mill tailings disposal site from intrusion




can be accomplished by a fence barrier.  Two types of fences are consid-




ered in this report.  A 5 to 6 foot high chain link fence with or without




several strands of barbed wire on top costs an average of $29.69/m to




install, but may range between $21.33/m and $49.21/m.  If more security




from intrusion is required, a 12 to 16 foot high security fence (prison




grade) will cost $84.51/m for installation, but may be as low as $73.49/m




or as high as $95.5Vm.  These costs include instalation, corner posts,



and a gate.  The effective life of these fences is assumed to be 100



years, if proper maintenance is performed.  Annual maintenance costs for




the fences are expected to be 1$ of the original expenditure for the



fences.
                                  B-11

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B.2.5  Irrigation




     The capital and annual operating expenditures for irrigation used in



this report have been taken from the NRC-DGEIS (NR 79).  All costs are



stated on a per hectare basis, except for submersible pumps.  Annual



operating expenditures for running and maintaining irrigation equipment




are expected to be $273 per year per hectare.  This value includes




fertilizer, power, operating labor, maintenance on the irrigation equip-




ment, and ground water analyses.  Installation of the irrigation




equipment, including pumps, and miscellaneous valves and nozzles, will




cost $1,070 per hectare.  It is expected that this equipment will need




replacement an average of every 20 years.  In addition, one submersible




pump is required for every 20 hectares to be irrigated at a cost of




$1,000 each.  Replacement of the submersible pumps can be expected every




5 years.








B.2.6  Matrix Fixation




     Uranium mill tailings could be incorporated into a concrete or




asphalt mixture, thus reducing the leachability of the tailings into the




hydrologic system.  A detailed discussion of the methods and require-




ments for fixing uranium mill tailings in a concrete or asphalt matrix



can be found in the NRC-DGEIS (NR 79).
                                  B-12

-------
     Detailed breakdown of the estimated capital expenditures and annual




operation costs for the various methods of matrix fixation are given in



Tables B-2 and B-3.  These tables have been taken directly from the




NRC-DGEIS (NR 79), Tables 11.9 and 11.10, respectively.








     From a cost standpoint,  significant savings can be realized in




initial capital costs and in annual operating expenditures if a cement




matrix is used rather than an asphalt matrix.  In addition, the method of




drying the tailings before incorporation into either a cement or asphalt




matrix has significant cost implications.  For both concrete and asphalt




fixation, initial capital costs are somewhat less expensive for




mechanically drying the tailings (via a thermal evaporator) than for




drying the tailings with a "dewatering filter bed" (i.e., a sand filter).




However, significant savings in annual operating expenditures can be




gained by using the "dewatering filter bed" rather than the thermal




evaporator.  That is, annual operating costs are at least a factor of two




less than those for a thermal evaporator for both cement and aslphalt



matrix fixation.








B.2.7  Tailings Transportation



     Three methods of hauling uranium mill tilings were considered:




truck, rail, and pipeline for slurry.  According to Ford, Bacon and



Davis, Utah, Inc. (FB 76-78), contract haulers can transport mill



tailings at a cost of $0.10/ton-mile.  For longer distances (e.g.,
                                  B-13

-------
                                 TABLE B-2
                Estimated  Capital  Costs of Matrix Fixation
                                                          .(a)
(thousands of 1978 dollars)

Equipment
Sand washing and drying
Lime neutralization
Thermal Evaporator
Cement Asphalt
230 230
670 670
Filter Bed
Cement Asphalt
230 230
670 670
Slimes filtration (vacuum disc
   filter)
1150
1150
Tailings dewatering bed
Evaporators
Evaporation pond
Asphalt fixation
Cement fixation
TOTAL
	
1470
	
	
1210
4750
	
1470
	
4400
	
7900
2120
	
2300
	
1210
6550
2120
	
2300
4400
	
9700
(a)NRC-DGEIS (NR 79), Table 11.9.
                                  B-14

-------
                                 TABLE B-3
                Annual Operating Costs for Matrix Fixation
                                                          .(a)

(thousands of

1978 dollars)

Thermal Evaporator
Costs
Salaries
Maintenance
Power
Fuel
Asphalt
Cement
Total (annual)
Cement
170
110
75
4,250
	
1,970
6,575
Asphalt
170
170
75
4,740
3,360
	
8,515

Filter
Cement
85
50
35
	
	
1,970
2,140

Bed
Asphalt
85
100
35
490
3,360
	
4,070
(a)NRC-DGEIS (NR 79),  Table 11.10.
                                  B-15

-------
50 miles or more) transporting uranium mill tailings by rail, at



$0.08/ton-mile, can offer some cost advantages over truck




transportation.  However, unless the tailings pile is located at a rail




head, the tailings will have to be hauled to the rail line by truck.








     Uranium mill tailings transportation by pipeline offers greatly




reduced operating expenditures as compared to either truck or rail, but




requires heavy initial capital and right-of-way costs.  According to




Dames and Moore (DA 77), a 7" diameter pipeline costs $63,840/mile to




construct and to reserve the right-of-way.  Transporting mill tailings




via a 7" diameter pipeline is estimated to cost $0.048/ton-mile.








B.2.8  Discount Rate




     The discount rate is assumed to be 7%.  This is the estimated




average real rate of return considering all elements of society (NR 76).




The real rate of return is independent of inflation (i.e., it is the




current rate of return minus the inflation rate).  The discount rate is



used for computing the present discounted value of future costs (e.g., to




maintain and replace fences in the future).








B.2.9  Present Worth of Future Costs




     Several control methods may require perpetual care or periodic



replacement in order to maintain the intended level of effectiveness.
                                  B-16

-------
For example, chemical stabilization is assumed to require replacement

every four years.  Fences are assumed to require annual maintenance, and

replacement every 100 years.  Finally, natural precipitation may need to

be supplemented with an irrigation system to maintain a proper vegetation

cover for surface stabilization.  The irrigation system is assumed to

require annual maintenance, and periodic replacement.




     The present worth of all future costs are included in the cost

breakdown shown in the tables where appropriate.  The formula used for

present worth calculations is:
                            PW =
where:    PW = present worth,
           C = replacement cost of the item considered, or
               its periodic maintenance cost,
           n = the useful life of the item, or the
               periodic maintenance period,
and        i = the annual discount rate.
This formula assumes maintenance and replacement continues indefinitely.

The annual discount rate used in all calculations is 1%.



B.2.10  Land Costs

     Smith and Lambert (SM 78) estimate that farmland costs $781 per

hectare, on average, and may range between $160 and $5,189 per hectare.
                                  B-17

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B.3  Cost Estimates For Disposal Options




     Using the estimated unit costs (from Table B-1) and assuming the



dimensions of the average inactive uranium mill tailings pile, we have




estimated costs for the tasks that are necessary to complete various




disposal options.  When considered as various combinations of the tasks,




the estimated costs offer numerous control options.  In actual practice,




the choice of a specific disposal option and actual control cost will




depend on such site-specific parameters as the radon emanation rate,




size, and condition of the specific mill tailings pile.








B.3.1  Option 1 - No Radon Control




     This option may be implemented by either constructing a fence around




the existing disposal site (thereby restricting access) or stabilizing




the existing mill tailings pile to reduce future wind and water erosion.








B.3.1.1  Option 1a - Fencing




     In this disposal option, the uranium mill tailings pile is left at




its existing surface location and-a fence is~erected around the site.  No




control of radon-222 releases, particulate releases, or ground water




impacts is provided, although fencing provides some control of direct



gamma radiation by preventing people from living near the tailings pile.




It is assumed that wind erosion can cause particulates to migrate as far



as 1000m from the pile.  Therefore, it is assumed that a 1000m




exclusionary zone is required on all sides of the tailings pile.
                                  B-18

-------
     The cost of constructing a fence can be expected to range between




$290,000 for a 5 to 6 foot high chain link fence and $820,000 for a



security fence of prison grade.  The present worth of annual maintenance




and replacement every 100 years is estimated to be $40,000 for a chain



link fence and $120,000 for a security fence.








     In either case, the fence encloses 593.4 hectares of land.  The




tailings pile is assumed to be on a 49-hectare site that is already




publically owned.  It is assumed that the remainder (i.e., 593-4 -49 =




544.4 hectares) must be purchased at a cost of $430,000.  The 49 hectares,



already under public ownership, is imposing a cost to society since it is




not available for alternative uses.  The best alternative use is assumed




to be agricultural.  That is, the market value (i.e., the opportunity




cost) of the land is estimated to be $40,000.  In total, the cost for the




"no control" option is $790,000, if a 5 to 6 foot high chain link fence




is used, and $2,410,000, if a security fence is employed.








B.3.1.2  Option 1b - Stabilization With No Radon Control




     The mill tailings pile is left in place in this disposal option but




is stabilized to prevent wind and water erosion.  Several of the existing



inactive tailings piles have already been stabilized with about six inches




of soil cover, vegetation, gravel, or rip-rap.  The equivalent of 0.5m of




rip-rap cover is required to ensure longevity.  A 15cm to 0.5m dike cover




would meet short-term requirements, but would be subject to both wind and




water erosion and thus subsequent degradation.  Rip-rap cover has been




utilized at one pile and experience with stabilization of large tailings






                                  B-19

-------
piles is quite limited.  This level of control might be accomplished



through the use of chemical sprays, which provide either a surface crust




or bind the surface tailings into a crust.  However, experience with such




methods has indicated that the resulting crusts are not resistant to




environmental degradation (e.g., Tuba City and Salt Lake City (FB 76).




The degradation results from intrusion by man and animals, ultraviolet




radiation, and various climatological effects.  Chemical sprays and




binders appear to require a protective layer of dirt or rip-rap to assure



even a relatively short lifetime of 10 years.  Thus, they have a limited




applicability for this level of control.








     The sides of the tailings pile must be shaped to a slope ratio of




8:1 to minimize future erosion and a 20m exclusionary zone should be




provided around the pile.  Besides the two types of fences (i.e., a 5 to




6 foot high chain link fence and a security fence), several stabilization




methods are considered here.  Vegetation could be employed, but may




require the purchase of a suitable type of top soil or may need an




irrigation system.  Potentially, rip-rap and gravel could provide




long-term wind and water erosion protection.  Finally, chemical



stabilizers provide erosion protection but are expected to need



replacement every 4 years.








     Table B-4 presents the cost and dimension estimates for the




alternative methods that will control particulates at the model uranium




mill tailings pile.
                                  B-20

-------
                                 TABLE B-4

                Costs and Dimensions of Particulate Control
Volume of earth work (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)
135000
247000
  2140
287000
Earth work

Stabilization
  Meg:  with no need to
       purchase soil
    with purchase of soil
  Irrigation
    (labor & equip.)
  Rip rap
  Gravel
  Chemical

Fencing
  5'-6' high chain link
  Security (prison grade)

Future Costs
  Irrigation
    (labor & equip.)
  Chemical stabilization
  5'-6' chain link fence
  Security fence

Value of Land
                    -Costs (in $1000 of 1978 dollars).
   200
   180
   620

    40
  3180
   630
   180
    60
   180
   110
   590
    10
    30

    20
                                  B-21

-------
     At a minimum, the total cost of providing wind and water erosion




protection for the model mill tailings pile will be $500,000.  This



includes enough earthwork to change the embankment slopes from 2:1 to



8:1, stabilization by vegetation that requires neither soil purchase or




irrigation, and a 5 to 6 foot high chain link fence.  On the other hand,




the level of control could cost as much as $3,600,000, if the model pile




must be stabilized by rip-rap and isolated by a security fence.








B.3.2  Controlling Radon Emissions with an Overburden




     As noted in the NRC-DGEIS (NR 79), radon emanation can be attenuated



by an appropriate thickness of overburden.  The overburden may be a layer




of soil or a combination of soil and a cap (i.e., a cap consisting of




asphalt, clay, or synthetic material).  For Option 2 (Existing Surface




Site, Covered to Control Radon) and Option 3 (New Site, Below Grade, With




Liner if Needed), seven types of overburden are considered for dimension




and cost estimation.  The required thickness of overburden needed to




provide the five selected radon attenuation levels for each type of




overburden are presented in Table B-5.








B.3.3.  Option 2 - Existing Surface Site,



        Covered to Control Radon Emissions



     This disposal option consits of covering the tailings pile at the



existing surface site for control of radon-222 releases.  In addition,




this control option reduces wind and water erosion of the mill tailings,




attenuates gamma radiation, and provides some control of ground water




contamination.  Basically, this option requires three steps to complete:






                                  B-22

-------
                                 TABLE B-5

   Thickness (meters) of Cover Required to Reduce Radon to Control Level

                                                        2
                              Radon Control Level (pCi/m /sec)

                               100     10     5     2     0.5

Soil(a)                        1.1    2.9   3-1*   4.1     5.1

Soil + 0.6 m Clay(b)           o.3    0.9   1.4   2.1     3-2

Soil + 1.0 m Clay(c)           o.3    0.7   0.8   1.0     1.9

Soil + Asphalt(d)               —    —    —    —      0.5

Soil + Synthetic(d)             —    —    —    —      0.5
        with average radon attenuating properties.
             includes both clay and soil.  If thickness is 0.6m or less
     then includes clay only.
(^Thickness includes both clay and soil.  If thickness is 1.0m or less
     then includes clay only.
(d'Asphalt and synthetic caps are assumed to reduce radon to at least
     1.0 pCi/m2 sec.  Thickness only includes soil.  The dashes (—)
     mean no soil is required.

Source:  NRC-DGEIS, Table K-6.1, p.K-27. (Ref. NR 79)
                                  B-23

-------
covering the mill tailings, stabilizing the pile against wind and water



erosion, and fencing the disposal area to prevent intrusion.  Although




only three steps are required, there are several ways of accomplishing




each of the steps.  These steps and their alternative methods are given




in Table B-6.  This leads to numerous possible combinations of methods to



implement this disposal option.








B.3.3.1  Dimensions




     All dimensions (which serve as the bases of the cost estimates) are




derived assuming that the existing uranium mill tailings piles and the




resultant disposal mounds are in the shape of truncated regular pyramids.



By assumption, the sides of the final disposal mound have a slope ratio

-------
                                 TABLE B-6

                   Control Methods for Disposal Option 2
             (Existing Surface Site,  Covered to Control Radon)
1.   Cover
     a. Soil (normal radon attenuation properties).
     b. Soil + 0.6m clay (no clay purchase required).
     c. Soil + 0.6m clay (clay purchase required).
     d. Soil + 1.0m clay (no clay purchase required).
     e. Soil + 1.0m clay (clay purchase required).
     f. Soil + asphalt.
     g. Soil + synthetic.
2.  Stabilization

     a. Vegetation (no soil or loam purchase required),
     b. Vegetation (soil or loam purchase required)
     c. Irrigation required (a or b)
     d. Irrigation not required (a or b)
     e. Rip rap
     f. Gravel
     g. Chemical
3.  Fence

     a.  5'-6'  high chain link fence
     b.  Security fence (prison grade)
                                  B-25

-------
of 8:1 in order to resist future wind and water erosion.  Also, an



exclusionary zone of 20m from the base of the final disposal mound is



assumed.  Finally, the dimensions and conditions of the average inactive




uranium mill tailings pile are those described in Section B.1.








B.3.3.2  Cost Estimates




     Cost estimates based on the dimensions of the average inactive




uranium mill tailings pile are presented, for each of five selected radon




attenuation levels, in Tables B-7 through B-11.  Cost estimates for




various tasks necessary to implement Option 2 are found in these tables.




Notice that the total cost of implementing Option 2 will vary with such




things as the desired radon attenuation level, the selected type of



overburden, the method of stabilization,  and the fencing.








     Several points concerning the derivation of the cost estimates need




some explanation:








     1.  The volume of earth work, specific to a type of cover, does not




include the volume of the cap.  That is,  in the case of clay caps, the




volume of the clay cap is not included as part of the volume of the earth



work.








     2.  Earth work includes excavating,  loading, hauling (up to one




mile), spreading, and compacting surface  soil.
                                  B-26

-------
                                 TABLE B-7

                     Costs and Dimensions for Disposal
                                                        2
             Option 2 with Control of Radon to 100 pCi/m /sec



Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)



Soil
1.1
415000
264000
2210
306000
t-.s (in !kinnn

Soil +
.6m Clay
.3
209000
251000
2160
292000
nf 1Q7fl Hnll;

Soil + Soil +
1m Clay Other
.3
209000
251000
2160
292000

Earth work                     630          240          240

Cap
  Clay
    with clay available          -          110          110
    with clay purchase           -          260          260
  Other
    asphalt                      -
    synthetic                    -

Stabilization
  Veg:  with no need to
       purchase soil           200          190          190
    with purchase of soil      660          630          6§0
  Irrigation
    (labor & equip.)            40           40           40
  Rip rap                     3^10         3240         3240
  Gravel                       680          650          650
  Chemical                     200          190          190

Fencing
  5'-6' high chain link         70           60           60
  Security (prison grade)      190          180          180

Future Costs
  Irrigation
    (labor & equip.)           120          110          110
  Chemical stabilization       630          600          600
  5'-6' chain link fence        10           10           10
  Security fence                30           30           30

Value of land                   20           20           20
                                  B-27

-------
                                 TABLE B-8

                     Costs and Dimensions for Disposal
                                                       2
             Option 2 with Control of Radon to 10 pCi/m /sec



Depth of cover (m)
Volume of cover (m3)
Aera of cover (m2)
Length of fence (m)
Area within fence (m2)
	 Pn


Soil
2.9
917000
295000
2330
339000
st-.s fin 
-------
                                 TABLE B-9

                     Costs and Dimensions for Disposal
Option 2 with Control of
2
Radon to 5 pCi/m /sec



Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)

Soil
3.4
1066000
304000
2360
349000
Soil +
.6m Clay
1.4
495000
269000
2230
312000
Soil + Soil +
1m Clay Other
.8
337000
260000
2200
301000
	 rVist. fin *10nn nf 1Q78 Hnnarsl 	
Earth Work                    1610

Cap
  Clay
    with clay available
    with clay purchase
  Other
    asphalt
    synthetic

Stabilization
  Veg:  with no need to
       purchase soil           230
    with purchase of soil      760
  Irrigation
    (labor 4 equip.)            40
  Rip rap                     3920
  Gravel                       780
  Chemical                     220

Fencing
  5'-6' high chain link         70
  Security (prison grade)      200

Future Costs
  Irrigation
    (labor & equip.)           140
  Chemical stablization        720
  5'-6' chain link fence        10
  Security fence                30

Value of Land                   30
 590
 210
 520
 200
 680

  40
3480
 690
 200
  70
 190
 120
 640
  10
  30

  20
 300
 290
 690
 190
 650

  40
3350
 670
 190
  70
 190
 120
 620
  10
  30

  20
                                  B-29

-------
                    TABLE  B-10
        Costs and Dimensions for Disposal
                                         2
Option 2 with Control of Radon to 2 pCi/m /sec

Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)

Earth Work
Cap
Clay
with clay available
with clay purchase
Soil
4.1
1283000
317000
2410
362000

1940
-
Soil +
.6m Clay
2.1
687000
281000
2280
324000
innn of 107?
880
210
520
Soil + Soil +
1m Clay Other
1.0
389000
263000
2210
305000
}/•?(•> 1 1 *D ¥*! f ]
330
360
870
  Other
    asphalt
    synthetic

Stabilization
  Veg:  with no need to
      purchase soil            240
    with purchase of soil      790
  Irrigation
    (labor & equip.)            40
  Rip rap                     4080
  Gravel                       810
  Chemical                     230

Fencing
  5'-6' high chain link         70
  Security (prison grade)      200

Future Costs
  Irrigation
    (labor & equip.)           140
  Chemical stabilization       750
  5'-6' chain link fence        10
  Security fence                30

Value of Land                   30
                               210
                               710

                                40
                              3630
                               720
                               210
                                70
                               190
                               130
                               670
                                10
                                30

                                20
 200
 660

  40
3390
 680
 190
  70
 190
 120
 630
  10
  30

  20
                     B-30

-------
                                  TABLE B-11
                      Costs and Dimensions for Disposal
                                                        2
             Option 2 with Control of Radon to 0.5 pCi/m /sec


Depth of cover (m)
Volume of cover (m3)
Area of cover (m2)
Length of fence (m)
Area within fence (m2)


Soil
5.1
1607000
335000
2470
381000
-(Vishs Mn !fc1
Soil +
.6m Clay
3-2
1006000
300000
2350
3^5000
000 of 1Q7ft rir
Soil +
1m Clay
1.9
631000
278000
2270
321000

Soil +
Other
.5
260000
255000
2180
296000

Earth work

Cap
  Clay
    with clay available
    with clay purchase
  Other
    asphalt
    synthetic

Stabilization
  Veg:  with no need to
      purchase soil
    with purchase of soil
  Irrigation
    (labor & equip.)
  Rip rap
  Gravel
  Chemical

Fencing
  5'-6' high chain link
  Security (prison grade)

Future Costs
  Irrigation
    (labor & equip.)
  Chemical stabilization
  5'-6'chain link fence
  Security fence

Value of Land
2430         1360          690
                           390
 250
 840

  50
4320
 860
 250
  70
 210
 150
 800
  10
  30

  30
              210
              520
              360
              870
 230
 750

  40
3880
 770
 220
  70
 200
 130
 720
  10
  30

  30
 210
 700

  40
3590
 710
 200
  70
 190
 120
 660
  10
  30

  30
                                        300
                                        760
 190
 640

  40
3290
 650
 190
  60
 180
 110
 610
  10
  30

  20
                                  B-31

-------
     3«  Caps are assumed to cover both the tailings and the crest of the



impoundment dikes.








     4.  Asphalt and synthetic caps are expected to reduce radon releases




to 1.0 pCi/m^/sec without additional soil cover.  As a result, cost




estimates for covers involving asphalt or synthetic caps have been



computed only for radon control levels of 1.0 pCi/m^/sec and below.








     5.  Several control methods in Table B-6 require periodic mainten-




ance and replacement of equipment (e.g.,  irrigation equipment, chemical




stabilizers, and fences).  The discounted present value of these future



costs have been computed in each case.








     6.  After completion of the control measures, it is expected that the




use of the land within the fences will be restricted.  Therefore,




alternative uses, such as agricultural, will be permanently denied.  This




opportunity cost needs to be considered in the decision-making process



along with the other costs.  For this purpose, the restricted land is



assumed to have agricultural uses, and the opportunity cost is equal to




the market value of the property.








B.3.3.3  Use of Tables B-7 Through B-11



     Since Tables B-7 through B-11 present only the costs of accomplishing




particular tasks that may be employed in a control option, it is important
                                  B-32

-------
that the reader understand the proper use of these tables for deriving the


total cost for a desired control option.





     After selecting the desired radon attenuation level and type of


overburden (i.e., reading down one column of the selected table) one can


calculate a total cost for the selected control option.^  The total


cost is then equal to the sum of the cost of the required overburden


(i.e., earth work plus cap costs), the cost of the specific method of


stabilization (plus the cost of irrigation if required), the cost of the


desired fence, the necessary future costs, and the opportunity cost of


the restricted land (i.e., the market value of the land).  For example,

                                                           ^
the total cost of attenuating to a radon flux equal 5 pCi/m /sec (refer


to Table B-9) is $1,220,000, if soil plus a 1.0m clay cap is used as an


overburden (assuming a suitable clay is locally available at no cost). It


is assumed the site is stabilized with vegetation requiring both the


purchase of top soil and irrigation equipment, and that a 5 to 6 foot


high chain link fence is required.
''The column labeled "Soil + Other" in Tables B-7 through B-11 actually
represents two separate types of overburden, the combinations of soil,
and asphalt or synthetic caps.  In either case, only the cost of the

asphalt or synthetic caps differ.
                                  B-33

-------
B.3-4  Option 3 - New Site, Below Grade, With Liner if Needed




     The objective of Option 3 is not only to reduce radon emanation and



gamma radiation, but also to provide greater hydrologic control than




would be afforded by Option 2.








B.3.4.1  Requirements




     In addition to the three steps necessary to implement Option 2, this




option requires excavating a special pit, installing a liner (if neces-




sary), and transporting the tailings to the pit site.  The need for a




liner depends on characteristics of the subsoil at the new site.  If the




subsoil is relatively impervious to moisture seepage (e.g., clay with a




high montmorillonite content or impervious shale), then a special liner




may not be required.  Also, selecting a new site for the pit, which is




above the water table, may obviate the need for a liner.  For this option,




transporting the tailings includes excavating the tailings from their




present site, hauling them to the new site, and depositing the mill




tailings in the pit.








     Like Option 2, there are several ways of accomplishing each step of




this option.  Table B-12 presents each step and their alternative



methods.  Considering each possible combination presented in Table B-12



leads to numerous methods of implementing this disposal option.

-------
                          TABLE B-12

             Control  Methods  for Disposal Option  3
         (New Site, Below  Grade, with Liner  if Needed)
1.  Tailings Transportation
    a.  Truck
    b.  Truck and rail
    c.  Pipeline

2.  Below Grade Excavation
    a.  Normal
    b.  Shale (ripping necessary)

3-  Liner
    a.  Clay (with clay available)
    b.  Clay (clay purchase required)
    c.  Asphalt
    d.  Synthetic
    e.  None

4.  Cover
    a.  Soil (normal radon attenuation properties)
    b.  Soil + 0.6m clay (with clay available)
    c.  Soil + 0.6m clay (clay purchase required)
    d.  Soil + 1.0m clay (with clay available)
    e.  Soil + 1.0m clay (clay purchase required)
    f.  Soil + asphalt
    g.  Soil + synthetic

5.  Stabilization
    a.  Vegetation (no soil or loam purchase required)
    b.  Vegetation (soil or loam purchase required)
    c.  Irrigation required (a or b)
    d.  Irrigation not required (a or b)
    e   Rip rap
    f.  Gravel
    g.  Chemical

6.  Fence
    a.  5'-6' high chain link fence
    b.  Security fence (prision grade)
                             B-35

-------
6.3-4.2  Dimensions and Cost Estimates




     For each of five selected radon attentuation levels, dimensions and



costs were calculated for the various control methods for implementing




Option 3 (Table B-12).  The distance to the new disposal site and the




geometric configuration of the pit are assumed constant in this analysis.




Several of the dimensions (and, therefore, the costs) also remain constant




regardless of the depth and type of overburden placed over the mill




tailings, while other dimensions (and costs) vary.  These constant costs




are given in Table B-13-








     As previously noted, there are 784,246m3 of uranium mill tailings




(weighing 1,325,376 short tons) to be excavated by dragline and hauled to




the pit site.  The area to be stabilized is 176,400m2 (i.e., the pit,




regardless of depth, is assumed to be square and 420m on a side).




Similarly, 1,840m of fencing will be required to enclose 211,600m2 of




land (including both the pit and the exclusionary zone which is 20m on




each side).  The excavated pit is assumed to be in the shape of a




truncated inverted regular..pyramid (i.e., with its base on top), whose




sides are required to have a slope ratio of 3:1.








     The pit site is assumed to be located 10 miles from the inactive



mill tailings site.  Rail heads are assumed to be situated one mile from




both the inactive tailings site and the pit site.  It is assumed that the




land for the pit and its exclusion zone will be purchased at the market
                                  B-36

-------
                               TABLE B-13

    Constant Costs for Below-Grade Disposal of Uranium Mill Tailings


                                                   $1000 1978 dollars

Excavate, load, spread, and compact tailings              1500

Tailings Transportation
  Truck                                                   1300
  Truck and rail                                          1100
  Pipline                                                 1280

Stabilization
  Veg:  with no soil purchase                              130
        with soil purchase                                 440
  Irrigation
    (labor and equip.)                                      30
  Rip rap                                                 2280
  Gravel                                                   450
  Chemical                                                 130

Fencing
  5'-6' high chain link                                     50
  Security (prison grade)                                  160

Land Cost                                                   20

Future costs
  Irrigation (labor and equip.)                            100
  Chemical stabilization                                   500
  5'-6' high chain link fence                               10
  Security fence                                            20
                                  B-37

-------
value of farmland.  For this disposal option "earthwork" means below-grade




excavation, hauling (up to one mile), dumping, spreading, and compacting



subsoil, and disposing of any excavated subsoil not used in the cover.




The costs that vary by radon control level are given in Tables B-14




through B-18 for each selected level.
                                  B-38

-------
                                 TABLE  B-14
                Variable  Costs  and  Dimensions  for Disposal
                                                        p
             Option 3 with Control of Radon to 100 pCl/m /sec

Depth of cover

(m)
Soil
1.1
Soil +
.6m Clay
.3
Soil +
1m Clay
.3
Soil +
Other
—
Vol. of pit
  with clay liner (m3)     1145000      1014000      1014000
  no clay liner (m3)        975000       837000       837000
Vol. of clay liner (m3)     170000       177000       177000
Area for other liner (m2)   172000       176000       176000
Vol. of clay cap (m3)          -          53000        53000
Area for other cap (m2)        -
Earth work
  No clay liner
    normal digging            2890
    shale                     4320
  Clay liner
    normal digging            3390
    shale                     5100

Liner
  Clay
    with clay available        350
    with clay purchase         850
  Other
    asphalt                    300
    synthetic                  760

Cap
  Clay
    with clay available
    with clay purchase
  Other
    asphalt
    synthetic
                         -Costs (in $1000 of 1978 dollars).
2480
3710

3000
4490
 370
 890

 310
 780
 110
 260
2480
3710

3000
4490
 370
 890

 310
 780
 110
 260
                                  B-39

-------
                                 TABLE  B-15

                Variable  Costs  and  Dimensions  for Disposal
                                                       2
             Option 3 with Control of Radon to 10 pCi/m /sec


Depth of cover (m)
Soil
2.9
Soil +
.6m Clay
.9
Soil +
1m Clay
.7
Soil +
Other
.
Vol. fo pit
  with clay liner (m3)     1436000      1111000      1078000
  no clay liner (m3)       1275000       941000       906000
Vol. of clay liner (m3)     162000       170000       172000
Area for other Iiner(m2)    163000       173000       174000
Vol. of clay cap (zn3)          -         104000       122000
Area for other cap (m2)        -
                          -Costs (in $1000 of 1978 dollars)-
Earth work
  No clay liner
    normal digging            3770         2790         2680
    shale                     5650         4170         4020
  Clay liner
    normal digging            4250         3290         3190
    shale                     6360         4920         4780

Liner
  Clay
    with clay available        330          350          360
    with clay purchase         810          850          860
  Other
    asphalt                    290          300          310
    synthetic                  720          770          770

Cap
  Clay
    with clay available          -          220          250
    with clay purchase           -          520          610
  Other
    asphalt                      -
    synthetic                    -
                                  B-40

-------
                                 TABLE  B-16
                Variable  Costs  and  Dimensions  for Disposal
                                                       2
              Option 3 with Control of Radon to 5 pCi/m /sec

Depth of cover

(m)
Soil
3.4
Soil +
.6m Clay
1.4
Soil +
1m Clay
.8
Soil +
Other
.
Vol. of pit
  with clay liner (m3)
  with no liner (m3)
Vol. of clay liner (m3)
Area for other liner (m2)
Vol. of clay cap (m3)
Area for other cap
1514000
1355000
 158000
 161000
1195000
1026000
 168000
 171000
 103000
                                                     1095000
                                                      924000
                                                      172000
                                                      174000
                                                      140000
Earth work
  No clay liner
    normal digging            4010
    shale                     6000
  Clay liner
    normal digging            4480
    shale                     6710

Liner
  Clay
    with clay available        330
    with clay purchase         790
  Other
    asphalt                    280
    synthetic                  710

Cap
  Clay
    with clay available
    with clay purchase
  Other
    asphalt
    synthetic
                          -Costs (in $1000 of 1978 dollars)-
   3040
   4550

   3540
   5290
    350
    840

    300
    750
    210
    510
                             2730
                             4090

                             3240
                             4850
                              360
                              860

                              310
                              770
                              290
                              700
                                  B-41

-------
                                 TABLE  B-17
                Variable^ Costs  and  Dimensions  for Disposal
                                                       2
              Option 3 with Control of Radon to 2 pCi/m /sec

Depth of cover

(m)
Soil
4.1
Soil +
.6m Clay
2.1
Soil +
1m Clay
1.0
Soil +
Other
.
Vol. of pit
  with clay liner (m3)
  no clay liner (m3)
Vol. of clay liner (m3)
Area for other liner (m2)
Vol. of clay cap (m3)
Area for other cap
1621000
1468000
 155000
 158000
1308000
1144000
 165000
 167000
 100000
                                                     1128000
                                                      958000
                                                      170000
                                                      173000
                                                      174000
Earth work
  No clay liner
    normal digging            4340
    shale                     6490
  Clay liner
    normal digging            4800
    shale                     7180

Liner
  Clay
    with clay available    	320
    with clay purchase  ~      780
  Other
    asphalt                    280
    synthetic                  700

Cap
  Clay
    with clay available
    with clay purchase
  Other
    asphalt
    synthetic
                          -Costs (in $1000 of 1978 dollars)-
   3390
   5070

   3870
   5800
    340
    820

    290
    740
    210
    500
                             2840
                             4240

                             3340
                             5000
                              350
                              850

                              300
                              760
                              360
                              870
                                  B-42

-------
                              TABLE B-18
              Variable Costs and Dimensions for Disposal
                                                      2
           Option 3 with Control of Radon to 0.5  pCi/m /sec


Depth of cover (m)
Vol. of pit
with clay liner (m3)
no clay liner (m3)
Vol. of clay liner (m3)
Area for other liner (m^)
Vol. of clay cap (m3)
Area of other cap (m2)


Earth work
No clay liner
normal digging
shale
Clay liner
normal digging
shale
Liner
Clay
with clay available
with clay purchase
Other
asphalt
synthetic
Cap
Clay
with clay available
with clay purchase

Soil
5.1

1771000
1620000
151000
153000
_
-
cjf^ fin 4*1000
•3 UO \J_il «p I \J\J\J


4800
7180

5240
7850


310
760

270
670


-
-
Soil +
.6m Clay
3.2

1482000
1323000
159000
162000
97000
-
nf 1Q7fl
OI I y 1 o


3920
5860

4390
6570


330
760

290
710


200
490
Soil +
1m Clay
1.9

1277000
1110000
166000
168000
169000
-
«4*^ll«*AMl



3290
4920

3780
5660


340
830

300
740


350
850
Soil +
Other
.5

1045000
872000
173000
175000
.
174000




2580
3860

3090
4630


360
870

310
780


-
-
Other
  asphalt
  synthetic
310
770
                                B-43

-------
B.4  Other Disposal Methods




     There are several high cost alternatives to the disposal methods



previosly considered.  These methods are discussed in the NRC-DGEIS




(NR 79).  Two of these methods are considered here: burial in a strip-



mine or underground mine, and nitric acid leching for the removal of




hazardous materials.  Potentially, these alternatives offer considerable




radon attenuation (below 0.5 pCi/m^/sec), but the long-term




environmental impact of these methods has not been tested.








B.4.1  Extraction and Disposal of Hazardous Materials




     Technology has not been developed for extracting radium or




nonradiological elements from the tailings, because there has been no need



for this method for disposing of tailings.








     A nitric acid leaching plant could be set up to remove the radium and




thorium in the tailings.  Tailings from this process would still require




some treatment although the radioactivity level would be considerably




lower.  Some of the nonradiologically hazardous elements would remain.




Seepage from the new pile would contain nitrates instead of the sulfates




found in a conventional mill tailings.  Nitrates are quite mobile if the



seepage reaches ground water.  The cost of chemical treatment of tailings




is as yet undetermined, but could be expected to be as expensive as the



original milling process, excluding ore grinding.  Since this technique is



expected to be only about 90% effective, some action would still be

-------
required to isolate the tailings from the biosphere and to dispose of the




extracted material in a licensed waste burial site.








     Uranium mill tailings disposal by a nitric acid leaching process




requires the construction and operation of a nitric acid leaching mill,




the disposal of the concentrated nitric acid leachate, and the disposal of



the residual tailings.  The construction and operation of a nitric acid




leaching mill is quite expensive.  The NRC-DGEIS (NR 79) estimates that a




model nitric acid leaching mill costs $35 million to construct and an




additional $37.7 million to equip (1978 dollars), while operating costs




are expected to run $12.50 per ton of processed uranium mill tailings.








     Assuming the model inactive mill pile contains 1,325,000 short tons




of tailings and a model nitric acid leaching mill can process 1,984 short



tons (1800 metric tons) of mill tailings and produce 55 short tons (50




metric tons) of nitric acid leachate per day, then 668 days of operation



are required to process the mill tailings.  In addition, approximately




37,000 short tons of nitric acid leachate will be generated.  Consequently,



the total operating cost for a model nitric acid leaching mill at the model




inactive mill tailings pile is expected to run $16.6 million.  Some of the



construction materials used in a model nitric acid leaching mill might be



employed at more than one inactive mill tailings site, or might have some




scrap value.  These possibilities are not analyzed here, due to the




uncertainties of apportioning construction costs and determining future




scrap values.  We therefore assume that each inactive mill tailings site
                                  B-45

-------
requires the construction of a new nitric acid leaching mill at a cost of




$35 million.  On the other hand, we assume that the nitric acid leaching



equipment can be used at more than one inactive mill tailings site.  As a




result, cost of the nitric acid leaching equipment is equal to its




depreciated value.  Assuming two years of use at the model inactive mill




tailings site, a fifteen year life expectancy for the nitric acid leaching




equipment, and straight-line depreciation, the expected cost of the nitric




acid leaching equipment is $5 million at each model inactive mill tailings




site.  An additional $5 million is added to cover the costs of transport-




ation between different mill tailings sites, set-up and take-down costs,




and extra wear and tear on the equipment, as well as other contingencies.




Therefore, we expect the total nitric acid leaching equipment costs to be




$10 million.  In total, we expect nitric acid leaching to cost $61.6




million (1978 dollars) to construct, equip, and operate the model inactive




mill tailings site.




     When combined in an asphalt or cement matrix, the nitric acid




leachate matrix has a volume of 17,08lm3 and requires a cover 10m thick



for proper disposal.  The disposal of the nitric acid leachate would



require a pit 13.^Sm deep and covering an area of .5 hectares (100m by




50m).  The possible costs of disposing of the nitric acid leachate are



presented in Table B-19.








     The NRC-DGEIS (NR 79) estimates that the concentration of radium



remaining in the residual tailings after nitric acid leaching is at least




an order of magnitude greater than background levels.  If soil with




average radon attenuation properties is available in the area, a 3-8m






                                  B-46

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                            TABLE B-19

              Costs of Nitric Acid Leachate Disposal
                      ($1000  of  1978 dollars)
     Task                                             Cost

Earth work
     Normal digging                                    200
     Shale                                             300

Fixation
     Asphalt                                           560
     Cement                                            380

Stabilization
     Vegetation
        No need to purchase soil                         4
        With soil purchase                              30
        Irrigation                                       2
     Rip rap                                            60
     Gravel                                             10
     Chemical                                            4

Fencing3
     5'-6' high chain link fence                        10
     Security (prison grade) fence                      40

Future costs
     Irrigation                                         10
     Chemical stabilization                             30
     5'-6' high chain link fence                         2
     Security (prison grade) fence                      10

Value of land                                            1
                             B-47

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thick cover will provide attenuation to  .1 pCi/m^/sec.  Assuming the



nitric acid leaching process does not significantly alter the quantity  of




residual tailings and the assumptions that were employed for Option 3




(Section B.3.4 — New Site, Below Grade, with Liner if Needed), then the




disposal costs for the residual tailings can be computed.  The costs of



disposing of the residual tailings are presented in Table B-20.








     In summary, nitric acid leaching of the tailings for the model



inactive mill site will cost $61.6 million.  Under the best conditions,




disposal of the nitric acid leachate can be expected to cost an additional




$600,000 (normal soil excavation, stabilization with vegetation (no



irrigation required), and isolation with a 5'-6' high chain link fence).




Under the worst conditions, the cost of disposing of the nitric acid




leachate will run $970,000 (shale excavation, rip rap stabilization and




security fence isolation).  Disposal costs for the residual tailings




will, at best, be $7,010,000, if no liner is required, excavation is in




normal soil, tailings are transported by truck and rail, vegetation



requiring no irrigation is used to stabilize the disposal site, and the




disposal site is isolated with a 5'-6'  high chain link fence.  On the




other hand, the costs of disposing the residual tailings could be as high




as $13,060,000, if a clay liner is used (and the clay must be purchased),




pit excavation is in shale, only truck transportation is available for




the tailings, and the disposal site is stabilized by rip rap and isolated




by a security fence.  As a result, the cost of uranium mill tailings




disposal at the model inactive mill site, via a nitric acid leaching




process can be expected to range between $96.9 and $103-3 million.
                                  B-U8

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B.4.2  Long-Term Radon and Hydrology Control



     It is not reasonable to expect that complete isolation of the




uranium mill tailings can be accomplished at the existing sites.  The




concept of complete long-term isolation (of both radon and ground water)




essentially requires special site selection and emplacement techniques.



The NEC DGEIS (NR 79) describes two such methods that will meet  this



criteria: deep disposal in an open-pit mine and deep disposal in an




underground mine.








     In the case of an open-pit mine, the mill tailings may be loosely




deposited in the pit but enclosed in a water tight liner and cap, or they




can be combined with asphalt or cement to prevent leaching into the




surface and ground water environment.  Table B-21 presents cost estimates




in the case where a nearby (i.e., within 10 miles) open-pit coal mine or




copper quarry is assumed to be available.  Long-term radon and hydrology




control can cost as little as $6,900,000.  This include only the costs




for dragline excavation of the tailings, truck and rail tailings



transport, and loose tailings disposal with an asphalt liner and cap.




These cost estimates are relatively low because it is assumed that there



is an operating open pit mine close to the mill tailings pile, and the



mine owners are willing to cover the mill tailings at no cost as part of



their post-operation reclamation of the mine site.  On the other hand,




the costs may increase to $57,550,000, if the mill tailings are deposited



in an abandoned open pit mine, transported by truck, dried by a thermal




evaporator, and incorporated into an asphalt matrix.  It is also assumed
                                  B-49

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                            TABLE  B-20

               Costs of Residual Tailings Disposal
                     ($1000 of 1978 dollars)
     Task                                             Cost

Earth work
     Clay liner not required
        Normal digging                                4200
        Shale                                         6290

Liner
     Clay
        With clay available                            320
        With clay purchase                             780
     Asphalt                                           280
     Synthetic                                         TOO
     None

Tailings excavation, loading,
  spreading and compacting                            1500

Tailings transportation
     Track                                            1300
     Truck and rail                                   1100
     Pipeline                                         1270

Stabilization
     Vegetation
        No need to purchase soil                       130
        With soil purchase                             440
        Irrigation equipment                            30
     Rip rap                                          2280
     Gravel                                            450
     Chemical                                          130

Fencing
     5'-6' high chain like fence                        50
     Security (prison grade) fence                     160

Future Costs
     Irrigation equipment                              100
     Chemical stabilization                            500
     5'-6' high chain link fence                        10
     Security (prison grade) fence                      20

Value of land                                           20
                             B-50

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that the disposal site is stabilized with vegetation requiring the




purchase of suitable top soil.  Unlike the previous control levels,




however, there is no long-term commitment to institutional maintenance and




the site will be available for alternative future uses.








     In another, it is assumed that an abandoned underground mine is




available nearby.  In this case, it is assumed tht the tailings will need




to be incorporated in an asphalt or cement matrix to prevent leaching.



Furthermore, holes will be bored into the mine cavities for depositing the




asphalt or cement matrix.  Cost estimates for deep disposal of the mill




tailings in an underground mine are presented in Table B-22.  This method




of tailings disposal will cost at least $13,150,000, but not more than




$27,480,000 to implement.
                                  B-51

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                                 TABLE B-21

                       Cost  Estimates  of  Deep  Disposal
                  When a Nearby Open-pit Mine is Available

                              (in 1978 dollars)
     Task                                                     ($1,000)

Evacuate & load tailings                                        1,200

Tailings transportation
  Truck                                                         1,330
  Truck & rail                                                  1,100
  Pipeline                                                      1,300

Tailings disposal
  Loose with liner & cap                                        4,600
  Cement fixation
    Thermal evaporator                                         17,900
    Filter bed                                                 10,830
  Asphalt fixation
    Thermal evaporator                                         24,930
    Filter bed                                                 17,840

Disposal of mine contents                                      28,130

Vegetation cover
  No need to purchase soil                       ___		690
  Soil purchase required                                        4,600
                                  B-52

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                                 TABLE B-22

                       Cost  Estimates  of  Deep Disposal
                 When  a Nearby  Underground  Mine  is  Available

                              (in 1978 dollars)
     Task                                                     ($1,000)

Evacuate & load tailings                                        1,200

Tailings transportation
  Truck                                                         1,330
  Truck & rail                                                  1,100
  Pipeline                                                      1,300

Bore holes                                                         20

Tailings disposal
  Cement fixation
    Thermal evaporator                                         17,900
    Filter bed                                                 10,830
  Asphalt fixation
    Thermal evaporator                                         24,930
    Filter bed                                                 17,840
                                  B-53

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                         References for Appendix B
(DA 77)   Dames & Moore,  1977,  "An Evaluation of the  Cost  Parameters  for
          Hypothetical Uranium  Milling Operations and Ore  Transportation
          Systems in the  Western United States," Argonne National
          Laboratory,  Job No.  10263-001-07.

(DO 78)   Dodge Building  Cost Services,  1978,  1978 Dodge Guide  for
          Estimating Public Works Construction Costs,  McGraw-Hill:  New
          York, N.Y.

(ME 77)   Means,  Robert Snow,  1977,  Building  Construction  Cost  Data 1977.
          Robert Snow Means, Co., Inc.:   Duxbury,  Mass.

(NR 76)   U.S.  Nuclear Regulatory Commission,  August  1976,  "Final Generic
          Environmental Statement on the Use  of Recycle  Plutonium in
          Mixed Oxide Fuel in Light  Water Cooled Reactors,"  NUREG-0002,
          Vol.  4.

(NR 79)   U.S.  Nuclear Regulatory Commission,  April 1979,  "Generic
          Environmental Impact  Statement on Uranium Milling," NUREG-0511.

(SM 78)   Smith,  C.  Bruce and Lambert,  Janet  A.,  June 1978,  "Technology
          and Costs  for Cleaning Up  Land Contaminated  with Plutonium," in
          "Selected  Topics:  Transuranium Elements  in  the General
          Environment," U.S. Environmental Protection Agency,
          ORP/CSD-78-1.
                                 B-54

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      APPENDIX C
The Proposed Standards

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                             PROPOSED STANDARDS



     The Administrator of the Environmental Protection Agency hereby




proposes to add a Part 192 to Title *IO of the Code of Federal Regulations




as follows:




             Part 192 - ENVIRONMENTAL PROTECTION STANDARDS FOR




                           URANIUM MILL TAILINGS




     Subpart A — Environmental Standards  for  the Disposal of Residual




        Radioactive Materials from Inactive Uranium Processing Sj.tes




Sec.




192.01      Applicability




192.02     Definitions




192.03     Standards




192.0*1     Effective date








             Subpart B - Environmental Standards for Cleanup of




            Open Lands  and Buildings  Contaminated with  Residual




        Radioactive Materials from Inactive Uranium Processing Sites




192.10     Applicability




192.11      Definitions




192.12     Standards




192.13     Effective date
                                    C-2

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                           Subpart C — Exceptions



192.20     Criteria for exceptions



192.21     Remedial actions for exceptional circumstances




(Authority: Section 275 of the Atomic Energy Act of 195**, 42 U.S.C. 2022,



as amended by the Uranium Mill Tailings Radiation Control Act of 1978,



PL 95-604.)








        Subpart A  — Environmental Standards  for Disposal of Residual




        Radioactive Materials from Inactive Uranium Processing Sites




192.01    Applicability




     This subpart applies to the disposal of residual radioactive material




at any designated processing site or depository site as part of any




remedial action conducted under Title I of the Uranium Mill Tailings



Radiation Control Act of 1978 (PL 95-604), or following any use of




subsurface minerals at such a site.




192.02    Definitions




     (a)  Unless otherwise indicated in this subpart, all terms shall have




the same meaning as in Title I of the Uranium Mill Tailings Radiation




Control Act of 1978.



     (b)  Remedial action means any action performed under Section 108 of




the Uranium Mill Tailings Radiation Control Act of 1978.




     (c)  Disposal means any remedial action intended to assure the



long-term, safe,  and  environmentally sound stabilization of residual




radioactive materials.
                                    C-3

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     (d)  Disposal site means the region within the smallest practical




boundaries around residual radioactive material following completion of




disposal.




     (e)  Depository site means a disposal site selected under Section




104(b) or 105(b) of the Uranium Mill Tailings Radiation Control Act of



1978.




     (f)  Aquifer means a geologic formation, group of formations,  or



portion of a formation capable of yielding usable quantities of ground




water to wells or springs.




     (g)  Ground water means water below the land surface in the zone of



saturation.




     (h)  Underground drinking water source means:




          (1) an aquifer supplying drinking water for human consumption, or



          (2) an aquifer in which the ground water contains less than




10,000 milligrams/liter total dissolved solids.




     (i)  Curie (Ci) means the amount of radioactive material which




produces 37 billion nuclear transformations per second.  One picocurie




(pCi) = 10~12 Ci.




     (3)  Waters of the United States, including the territorial seas



means "navigable waters," as defined in the Federal Register, Volume 44,




page 32901, June 7, 1979.  (Comment;  This definition is taken from the




Regulations for the National Pollutant Discharge Elimination System,




40 CFR 122.3(t).  In essence, it includes all surface waters which the




public may traverse, enter, or draw food from.)
                                    C-4

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192.03    Standards



     Disposal of residual radioactive materials shall be conducted in a



way that provides a reasonable expectation that for one thousand years




following disposal:



          (a) The average annual release of radon-222 from a disposal site



to the atmosphere by residual radioactive materials shall not exceed




2 pCi/m2-sec, and



          (b) Substances from residual radioactive materials released




after disposal to an underground drinking water source shall not cause




              (1)  the concentration of that substance in the ground water




to exceed the level specified in Table A, or




              (2) an increase in the concentration of that substance in




the ground water, where the concentration of that substance prior to



remedial action exceeds the level specified in Table A for causes other




than residual radioactive materials.




This subsection shall apply to the dissolved portion of any substance




listed in Table A at any distance greater than 1.0 kilometer from a




disposal site which is part of an inactive processing site, or greater




than 0.1 kilometer if the disposal site is a depository site.



          (c)  Substances released from residual radioactive materials



after disposal shall not cause an increase in the concentration of any




substance in any waters of the United States, including the territorial



seas.



192.04  Effective date




     The standards of this Subpart shall be effective 60 days from




promulgation of this rule.
                                    C-5

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              Subpart B — Environmental Standards for Cleanup



           of Open Lands and Buildings Contaminated with Residual




        Radioactive Materials from Inactive Uranium Processing Sites




192.10   Applicability




     This subpart applies to open lands and buildings which are part of any



processing site designated by the Secretary of Energy under PL 95-604,




Section 102.  Section 101 of PL 95-60H, states that "processing site"



means —




     (A) any site, including the mill, containing residual radioactive




materials at which all or substantially all of the uranium was produced



for sale to any Federal agency prior to January 1, 1971 under a contract




with any Federal agency, except in the case of a site at or near Slick



Rock, Colorado, unless —



        (i) such site was owned or controlled as of January 1, 1978, or is



     thereafter owned or controlled, by any Federal agency, or




        (ii) a license (issued by the  (Nuclear Regulatory) Commission or




     its predecessor agency under the Atomic Energy Act of 195*1 or by a



     State as permitted under section 27^ of such Act) for the production




     at such site of any uranium or thorium product derived from ores is



     in effect on January 1, 1978, or  is issued or renewed after such




     date; and




     (B) any other real property or improvement thereon which —




        (i) is in the vicinity of such site, and




        (ii) is determined by the Secretary, in consultation with the




     Commission, to be contaminated with residual radioactive materials




     derived from such site.
                                    C-6

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Any ownership or control of an area by a Federal agency which is acquired



pursuant to a cooperative agreement under this title shall not be treated



as ownership or control by such agency for purposes of subparagraph (A)(i).




A license for the production of any uranium product from residual radioac-



tive materials shall not be treated as a license for production from ores




within the meaning of subparagraph (A)(ii) if such production is in



accordance with section 108(b).








192.11   Definitions




     (a) Unless otherwise indicated in this subpart, all terms shall have



the same meaning as defined in Title I of the Uranium Mill Tailings




Radiation Control Act of 1978.




     (b)  Remedial action means any action performed under Section 108 of




the Uranium Mill Tailings Radiation Control Act of 1978.




     (c) Open land means any surface or subsurface land which is not a




disposal site and is not covered by a building.



     (d) Working Level (WL) means any combination of short-lived radon




decay products in one liter of air that will result in the ultimate




emission of alpha particles with a total energy of 130 billion electron



volts.



     (e) Dose equivalent means absorbed dose multiplied by appropriate




factors to account for differences in biological effectiveness due to the



type and energy of the radiation and other factors.  The unit of dose




equivalent is the "rem."
                                    C-7

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     (f) Curie (Ci) means the amount of radioactive material which




produces 37 billion nuclear transformations per second.   One picocurie



(pCi) = 10-12 Ci.








192.12    Standards




     Remedial actions shall be conducted so as to provide reasonable




assurance that —



     (a)  The average concentration of radium-226 attributable to residual




radioactive material from any designated processing site in any 5 cm




thickness of soils or other materials on open land within 1 foot of the



surface, or in any 15 cm thickness below 1 foot, shall not exceed 5 pCi/gm.




     (b)  The levels of radioactivity in any occupied or occupiable




building shall not exceed either of the values specified in Table B



because of residual radioactive materials from any designated processing




site.



     (c)  The cumulative lifetime radiation dose equivalent to any organ of



the body of a maximally exposed individual resulting from the presence of




residual radioactive materials or byproduct materials shall not exceed the



maximum dose equivalent which could occur from radium-226 and its decay



products under paragraphs (a) and (b) of this section.








192.13   Effective date




     The standards of this Subpart shall be effective 60 days after




promulgation of this rule.
                                    C-8

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                           Subpart  C  —  Exceptions




192.20  Criteria for exceptions



     Exceptions to the standards may be justifiable under any of the




following circumstances:



     (a)  Public health or safety would be unavoidably endangered in




attempting to meet one or more of the requirements of Subpart A or



Subpart B.




     (b)  The goal of environmental protection would be better served by




not satisfying cleanup requirements for open land,  Sec. 192.12(a) or the




corresponding part of Sec. 192.12(c).  To justify an exception to these



requirements there should be a clearly unfavorable imbalance between the




environmental harm and the environmental and health benefits which would



result from implementing the standard.  The likelihood and extent of




current and future human presence at the site may be considered in




evaluating these benefits.




     (c)  The estimated costs of remedial actions to comply with the




cleanup requirements for buildings, Sec 192.12(b) or the corresponding




part of Sec. 192.12(c), are unreasonably high relative to the benefits.




Factors which may be considered in this judgment include the period of



occupancy, the radiation levels in the most frequently occupied areas, and



the residual useful lifetime of the building.  This criterion can only be




used when the values in Table B are only slightly exceeded.



     (d)  There is no known remedial action to meet one or more of the



requirements of Subpart A or Subpart B.  Destruction and condemnation of




buildings are not considered remedial actions for this purpose.
                                    C-9

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192.21  Remedial actions for exceptional circumstances

     Section 108 of PL 95-604 requires the Secretary of Energy to select

and perform remedial actions with the concurrence of the Nuclear Regulatory

Commission and the full participation of any State which pays part of the

cost, and in consultation, as appropriate, with affected Indian tribes and

the Secretary of the Interior.  Under exceptional circumstances satisfying

one or more of the conditions 192.20(a), (b), (c), and (d), the Department

of Energy may select and perform remedial actions, according to the proce-

dures of Sec. 108, which come as close to meeting the standard to which

the exception applies as is reasonable under the exceptional circumstances.

In doing so, the Department of Energy shall inform any private owners and

occupants of affected properties and request their comments on the selected

remedial actions.  The Department of Energy shall provide any such comments

to the parties involved in implementing Sec. 108 of PL 95-604.  The

Department of Energy shall also inform the Environmental Protection Agency

of remedial actions for exceptional circumstances under Subpart C of this

rule.
                                                   U.S.  Environmental Protection
                                                   Region V, Library
                                    c-10            230  South Dearborn Street
                                                   Chicago, Illinois 60604

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                                  TABLE A

     Arsenic 	 0.05   milligram/liter

     Barium 	 1.0    milligram/liter

     Cadmium 	 0.01   milligram/liter

     Chromium 	 0.05   milligram/liter

     Lead	0.05   milligram/liter

     Mercury 	 0.002  milligram/liter

     Molybdenum 	 0.05   milligram/liter

     Nitrate nitrogen	10.0    milligram/liter

     Selenium 	 0.01   milligram/liter

     Silver 	 0.05   milligram/liter



Combined radium-226 and radium-228	5.0   pCi/liter

Gross alpha particle activity (including

 radium-226 but excluding radon and  uranium)	15.0   pCi/liter

Uranium	10.0   pCi/liter







                                  TABLE B

Average Annual Indoor
 Radon Decay Product Concentration
  (including background)	•	0.015 WL

Indoor Gamma Radiation
  (above background)	0.02  milliroentgens/hour
                                   C-ll

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U.S. Environmental Protection Agency
Region V, Library
230  South Dearborn Street
Chicago, Illinois  60604 x^

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