ML23151A581

PR-020,040 - 62FR39093 - Radiological Criteria for License Termination: Uranium Recovery Facilities

ML23151A581
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Issue date:	07/21/1997
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62FR39093, PR-020, PR-040
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KEYWORD: ADAMS Template: SECY-067 07/21/1997 PR-020, 040 - 62FR39093 - RADIOLOGICAL CRITERIA FOR LICENSE TERMINATION: URANIUM RECOVERY FACILITIES PR-020, 040 62FR39093 RULEMAKING COMMENTS Document Sensitivity: Non-sensitive - SUNSI Review Complete

DOCKET NO. PR-020, 040 (62FR39093) In the Matter of RADIOLOGICAL CRITERIA FOR LICENSE TERMINATION: URANIUM RECOVERY FACILITIES DATE DATE OF TITLE OR DOCKETED DOCUMENT DESCRIPTION OF DOCUMENT 07/22/97 07/01/97 10/06/97 10/06/97 10/06/97 10/08/97 10/08/97 10/06/97 10/06/97 10/06/97 10/02/97 10/06/97 FEDERAL REGISTER NOTICE - REQUEST FOR ADDITIONAL COMMENT ON URANIUM RECOVERY FACILITIES COMMENT OF KENNECOTT URANIUM COMPANY (OSCAR PAULSON) ( COMMENT OF WYOMING MINING ASSOCIATION (MARION LOOMIS, EXEC. DIRECTOR) (

2)

COMMENT OF NATIONAL MINING ASSOCIATION (SHAW, PITTMAN, POTTS & TROWBRIDGE) (

3)

COMMENT OF WESTERN NUCLEAR, INC. {STEPHANIE J. BAKER) (

4)

COMMENT OF COTTER CORPORATION (RICH D. ZIEGLER, EXEC. V.P.) (

5) 0/09/97 10/03/97 COMMENT OF UMETCO MINERALS CORPORATION (JOHNS. HAMRICK) (

6) 10/14/97 10/06/97 COMMENT OF ILLINOIS DEPARTMENT OF NUCLEAR SAFETY

{STEVEN C. COLLINS) {

7) 10/17/97 10/06/97 COMMENT OF ENVIRONMENTAL PROTECTION AGENCY (JOHN M. KARHNAK, DIRECTOR) (

8) 12/18/97 11/28/97 COMMENT OF ENVIRONMENTAL PROTECTION AGENCY (JOHN M. KARHNAK, DIRECTOR) (

9) 12/18/97 11/28/97 COMMENT OF ILLINOIS DEPARTMENT OF NUCLEAR SAFETY (JOSEPH G. KLINGER) (

10) 02/10/98 02/09/98 COMMENT OF FOR A CLEAN TONAWANDA SITE

{JAMES M. RAUCH) {

11) 04/07/99 04/06/99 FEDERAL REGISTER NOTICE - FINAL RULE

1)

DOCKET NUMBER PROPOSED RULE ~"""'---_,,,. __ 0 NUCLEAR REGULATORY COMMISSION 10 CFR Part 40 '99 APR - 7 P 2 :4 9 RIN 3150-AD65 OF I Rt AD,' Radiological Criteria for License Termination of Uranium Recovery Facilities AGENCY: Nuclear Regulatory Commission. ACTION: Final rule.

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) is amending its regulations regarding decommissioning of licensed thorium mills and uranium recovery facilities to provide specific radiological criteria for the decommissioning of lands and structures. This final rule uses the existing soil radium standard to derive a dose criterion (benchmark approach) for the cleanup of byproduct material other than radium in soil and for the cleanup of surface activity on structures to be released for unrestricted use. This final rule is intended to provide a clear and consistent regulatory basis for determining the extent to which lands and structures can be considered to be decommissioned.

~ 1/ 1 JC/C,tJ EFFECTIVE DA TE: This regulation becomes effective on [SO dl!lys l!lfter puelieatien in the .feeleral Regis~erj. FOR FURTHER INFORMATION CONTACT: Frank Cardile, telephone: (301) 415-6185; e-mail: fpc@nrc.gov; or Elaine Brummett, telephone: (301) 415-6606, e-mail: esb@nrc.gov, Office of pµ1,. ~ '1 /,~ I CJq a:f ~ 'I FR 17501,

2 Nuclear Material Safety and Safeguards, U.S. Nudear Regulatory Commission, Washington, DC 20555-0001. SUPPLEMENTARY INFORMATION: I. Introduction. II. Background. Ill. Summary of Public Comments and Responses to Comments. IV. Agreement State Compatibility. V. Final Environmental Assessment Availability. VI. Paperwork Reduction Act Statement VII. Regulatory Analysis. VIII. Regulatory Flexibility Certification. IX. Backfit Analysis. X. Small Business Regulatory Enforcement Fairness Act. XI. Criminal Penalties. I. Introduction The NRC is amending its regulations regarding decommissioning of licensed thorium mills and uranium recovery (UR) facilities (conventional uranium mills and uranium extraction processes such as in situ leach (ISL) facilities) to provide radiological criteria for the decommissioning of lands and structures. These criteria apply to the decommissioning of licensed UR facilities subject to the NRC's jurisdiction and will also apply to thorium mills if any

3 become licensed in the future. The criteria apply to decommissioning of UR faci1ities that operate through their normal lrfetime and to those that may be shut down prematurely. The NRC will apply these criteria in determining the adequacy of remediation of residual radionuclides resulting from the possession or use of byproduct material1. The intent of this rulemaking is to provide a clear and consistent regulatory basis for determining the extent to which lands and structures at UR facilities must be remediated before decommissioning of a site can be considered complete and the license terminated. The NRC has previously applied site release criteria for decommissioning on a site-specific basis using existing guidance for surface activity and radionuclides other than radium in soil. The NRC believes that inclusion of criteria in the regulations will result in more efficient and consistent licensing actions related to site remediation activities.

11. Background On August 22, 1994 (59 FR 43200), the NRC published a proposed rule to amend 10 CFR Part 20 of its regulations "Standards for Protection Against Radiation" to include radiological criteria for license termination as subpart E. The proposed rule applied to uranium mills and other NRC-licensed facilities, but did not apply to mill tailings or to soil radium cleanup at mills because they are regulated under 10 CFR Part 40, Appendix A.

On July 21, 1997 {62 FR 39058), the NRC published a final rule that codified radiological criteria for license termination for NRC licensees, but excluded UR facilities. The NRC excluded 1A:s defined in 10 CFR Part 40, byproduct material Is the tailings or wastes produced by the extraction of uranium or thorium from any ore processed primarily for its source material content, including discrete surface wastes resulting from uranium solution extraction processes.

4 UR facilities from the scope of the final cleanup rule to allow further consideration of the issues unique to the decommissioning of these facilities. Th~ unique issues include the existing regulatory framework for UR facilities and the nature of contamination at UR facilities, both of which are discussed below. Under the existing regulatory framework for UR facilities, the Environmental Protection Agency (EPA) has the authority to set cleanup standards for uranium and thorium mills and, based on that authority, issued regulations in 40 CFR Part 192 that contain some decommissioning criteria for these facilities. NRC's regulations in 1 0 CFR Part 40, Appendix A, Criterion 6(6), conform to EPA's standards for radium in soil. Appendix A also provides ground-water protection criteria. Therefore, this rulemaking addresses only the radiological criteria for decommissioning of lands and structures. The rule only applies to those UR facilities that do not have an approved decommissioning plan for buildings and soil when the rule becomes effective. The sites with approved decommissioning plans may request an amendment to their license to adopt the criteria of this rule after the revision to Criterion 6(6) is promulgated. The applicable cleanup standards for soil radium in 10 CFR Part 40, Appendix A, Criterion 6(6), address the main contaminant at uranium mills in the large areas where windblown contamination from the tailings pile has occurred, and to a lesser extent, at ISLs in holding/settling ponds and process or bleed solution spills. 'These standards require that the concentration of radium (Ra-226 at UR facilities, Ra-228 at thorium mills) not exceed the background level by more than 5 pCi/g (0.19 Bq/g) in the first 15 cm (6 inches) of soil and 15 pCi/g (0.56 Bq/g) for every subsequent 15 cm (6 inch) layer. However, in other mill and ISL site areas proximate to locations where radium contamination exists (e.g., under/around the mill/process building, in a yellow cake storage area, and under/around an ore crusher), uranium

5 (U-nat) is the radionuclide of concern. At least one mill site must also address soil cleanup of thorium (Th-230, the parent of Ra-226, is usually in approximate equilibrium {same activity concentration) with Ra-226) because thorium is more mobile in the acidic milling solutions and leaches farther into the ground than the radium under raffinate ponds and heap leach pads. Because 1 0 CFR Part 40, Appendix A, does not have cleanup standards for surface activity or for soil contamination from radionuclides other than radium, NRC guidance documents have been the source of cleanup criteria for residual uranium, thorium, and building surface activity. An additional difficulty for remediation of UR facilities is that the residual radionuclides to be addressed in the site decommissioning are also present in the surrounding background soil in elevated and widely variable concentrations. Some mill sites even have uranium mine pits and/or piles of overburden soil containing low-grade ore on or adjacent to the areas to be remediated. This complicates the determination of background values and limits the ability of the licensee to distinguish residual radioactivity from naturally occurring (in-situ) radioactivity. To allow for consideration of these issues, the NRC also published, on July 21, 1997 (62 FR 39093), a request for additional comments on regulatory options for decommissioning of UR facilities. Included as part of the request was a discussion of an option to codify a dose objective for radionuclides other than radium (uranium and thorium) at UR facilities consistent with the radium cleanup standard. Under this approach, UR facilities would use the dose, excluding radon, from radium at the cleanup standard in existing 10 CFR Part 40, Appendix A, Criterion 6(6), as a benchmark for the cleanup of building surface activity and radionuclides other than radium in soil. Commenters were requested to provide input on options for decommissioning and, specifically, on the benchmark approach.

6 Use of the benchmark approach would provide for a common dose criterion across a UR site for those areas contaminated with radium and for those areas contaminated with other radionuclides. The radium dose benchmark approach would require UR licensees subject to the rule to calculate the potential total effective dose equivalent to the average member of the critical group for the site that would result from the radium standard within 1000 years, based upon site-specific parameters. These licensees would be required to provide justification for the models and parameters selected in the dose calculations. The dose from the 5 pCi/g (0.19 Bq/g) radium standard would be applicable for most of the site contamination. Licensees would then remediate the site such that the residual radionuclides (byproduct material) remaining on the site that are distinguishable from background would not result in a dose that is greater than that which would result from the radium soil standard. The radionuclides of concern are uranium and thorium, because it is assumed that the progeny of Ra-226 are at acceptable levels when the radium standard is achieved. Licensees would also be required to demonstrate that doses were "as low as is reasonably achievable" (ALARA). In the unlikely event that a site benchmark dose (before application of ALARA) exceeds 100 mrem/yr (1 mSv/y.r), the NRC staff would consult with the Commission before approving such a benchmark dose. Ill. Summary of Public Comments and Responses to Comments Comments received on the 1994 proposed rule for 10 CFR Part 20 subpart E were summarized in NUREG/CR-6353 and in the final rule notice (62 FR 39058, July 21, 1997). The eleven responses (nine commenters) to the July 21, 1997, request for additional comments on radiological criteria for UR facilities are addressed here.

7 A. Comments on Approach to the Criteria One commenter indicated that the standards should be technically-based, protective of human health, and based on a substantial fraction of the 100 mrem/yr {1 mSv/yr) public dose limit The use of dose-objective standards was encouraged. Evaluation of radon and thoron exposure was considered essential. This commenter also pointed out that the benchmark approach would codify a different dose limit for each facility. The EPA commented that the soil radium standard of 5 pCi/g (0.19 Bq/g) is consistent with the minimally acceptable dose limit of 15 mrem/yr (0.15 mSv/yr) for the residential scenario, and that for other land use scenarios, the cleanup standards are more stringent for Ra-226, Ra-228, Th-232, and Th-230. The EPA also cautioned that a dose limit for uranium cleanup should not exceed 15 mrem/yr (0.15 mSv/yr). A third commenter stated that the proposed rule is not acceptable because doses resulting from the benchmark approach could exceed 100 mrem/yr; NRC's existing guidance on cleanup of uranium, thorium, and surface activity should be used to set the minimum requirements; the expected dose from the radium standard should be clarified; the radon dose should be included in demonstrating compliance; and the time frame for dose modeling should be 10,000 years. The commenter also indicated that the proposed approach seems to allow a total dose of twice *the radium dose; and that if more types of areas are to be included than those indicated in the proposal, then the enlargement of scope would require additional notice and review. Six other commenters supported the Ra-226 benchmark dose approach for cleanup of other radionuclides such as U-nat, Th-230, and Th-232. These commenters indicated that the existing regulatory framework is appropriatb and prm,ides for flexibility to allow optimum tailings

8 disposal on a site-specific basis. One of these commenters also point~d out that uranium mill sites will be turned over to the custodial care of the Department of Energy (DOE) or the State for long-term care, effectively eliminating substantial portions of these sites from the public exposure pathways. In addition, some of the vicinity properties remediated with neighboring abandoned mills (under the DOE's's Uranium Mill Tailings Remedial Action Project) have deposits of contamination (Ra-226, Th-230, or U-nat) above the limits remaining under the supplemental standards provisions of 40 CFR 192.21. A. Response: The NRC agrees with the need to develop regulations that are protective of public health and safety with regard to decommissioning of UR facilities. NRC has previously addressed considerations related to radioactivity and dose to the put)lic, public health aspects, fraction of the 100 mrem/yr (1 mSv/yr) dose, and the rationale for excluding the radon dose in Sections A2.2.1, A.2.2.2, and F.6 of the July 21, 1997, Federal Register notice (62FR at 39060-64 and 39082) for the final rule for 10 CFR Part 20, subpart E; those discussions remain applicable to this final rulemaking. As discussed above, the UR facilities have large areas contaminated with radium in soils where the existing radium standard is applied. The NRC believes that it is important to promulgate cleanup standards for other residual radionuclides that are consistent with the radium cleanup standards. Use of such an approach would result in a common dose criterion across an entire UR site, both for those areas contaminated with radium and for those areas contaminated with uranium and thorium. As noted above, the 5 pCi/g radium standard was promulgated by EPA for UR sites. The 5 pCi/g radium value has also been recommended as an exemption level by the Board of Directors of the Conference of Radiation Control Program Directors (October 1998) for the Suggested State Regulations on technologically enhanced naturally occurring radioactive materials.

9 The NRC staffs preliminary dose modeling, using realistic parameter values and the RESRAD code, indicates that at typical UR facilities, where the background radiation results in doses of over 200 mrem/yr (2.0 mSv/yr), the Ra-226 standard of 5 pCi/g (0.19 Bq/g) could typically result in a potential peak annual dose on the order of 20 to 35 mrem/yr (0.2 to 0.35 mSv/yr) to the average member of the critical group. Although it is possible that some site-specific parameter values and subsurface contamination could result in a higher benchmark dose than that estimated by the staff for the various scenarios, the staff has high confidence that a site-specific dose using the benchmark approach will typically be a small fraction of 100 mrem/yr (1 mSv/yr), and in all cases will not exceed 100 mrem/yr (1 mSv/yr). The rule also requires li~nsee's to demonstrate that doses are AlARA which should result in a potential dose of less than 25 mrem/yr (0.2 mSv/yr) from the residua_! Ra-226 on the remediated site for most sites. Therefore, the potential health risk should be similar to the NRC dose limit established for other facilities in Part 20, subpart E, and approximate the le~el suggested in the EPA comment The radium benchmark dose modeling results are greater than the 5 pCi/g (0.19 Bq1g) radium modeling results reported by the EPA The main reason for the difference in results is that the EPA modeled a much smaller area of contamination than that used by NRC staff (100 m2 versus 404,687 m2). Also, EPA modeled a much smaller fraction of time an individual would spend outdoors (0.02 versus 0.25) and used a less conservative root depth value (0.9 versus 0.25 meters) which generally decreases the calculated potential dose. What is not factored into the dose modeling is the low probability of anyone constructing a house or growing a large garden on the areas of residual contamination at these facilities. The UR facilities are in semi-arid (7-15 inches (18-39 cm) annual precipitation), sparsely populated areas (1-13 persons/mile2(0.4-5 persons/km2)) where mining and grazing (3 cows/acre (1 cow/1348 m2)) are the main land uses.

The existing regulatory framework does not provide criteria for the cleanup of radionuclides other than radium in soil. Also, the existing guidance does not provide dose criteria, so additional criteria are warranted. In areas where there is more than one residual radionuclide, the benchmark dose would apply to the sum of all radionuclides present in that area (i.e., radium, uranium, thorium, etc.). This is indicated in the rule text, and in draft guidance for implementation of the benchmark approach, where it is stated that, for each 100 m2 area, the unity rule will apply such that the sum of the ratios for each radionuclide of the concent~tion present to the concentration limit may not exceed 111" (i.e., unity). The rule text and guidance also stipulate that the total effective dose equivalent limit is based on the peak annual dose within a 1000 year period to the average member of the critical group. This time frame is in keeping with the EPA regulatory time frame for these facilities (40 CFR Part 192). Only portions of uranium mill sites and no portion of ISL facilities are anticipated to be turned over to the custodial care of Government entities. The radium standard applies to all areas of a site except the disposal cell, regardless of Mure use. The NRC staff plans a similar approach for the criteria for other radionuclides. The restricted use of areas that will be in perpetual custodial care could be considered under the Al.ARA provision, if cleanup is drfficult or expensive in these areas. B. Radionuclides at UR Sites are Naturally Occurring and of Variable Concentration in Nature Several commenters indicated that the residual radionuclides at UR sites (uranium, thorium, radium) are naturally occurring in the local environment and that there is significant variability in soil background concentrations of these radionuclides, in particular at UR facilities where uranium pit mines or mineral outcrops exist. This leads to variability in potential dose

11 such that the 25 mrem/yr (0.25 mSv/yr) dose in Part 20 subpart E would be indiscernible in the natural variability of background at a UR site. Any concentration standard must account for the significant variability in background and state that the limits are for "concentrations above background" at the different areas of the site. Also, two commenters indicated that a statistical approach, not just an average value, should be used to determine the background values for a site. It was also mentioned that measurement of U-238 and Th-230 at levels above background, which result in an annual dose to residents of 25 mrem (0.25 mSv), would not be possible using reasonably available field techniques and that the additional cost of laboratory analyses to demonstrate compliance could be $100,000 per acre. Several commenters stated that there is no reliable way to distinguish natural (in situ) ore material from processed (licensed) ore. A related concern was that decommissioning standards for UR facilities must not regulate mining activities and the associated ore material that may be present at UR sites. B. Response: As noted above in Section 11, and as described in the rule implementation guidance, the radionuclide dose limit is applied to the level of licensed (byproduct) material distinguishable from background. Site cleanup guidance indicates that background values should be based on areas with characteristics similar to the contaminated area(s) and that distinct areas of the site could have different background values. Statistical approaches, such as those discussed in the Multi-Agency Radiation Survey and Site Investigation Manual (NUREG-1575, 1997), will be considered. Field measurements for soil U-nat and Th-230 in general are difficult and not just in the concentration equivalent of 25 mrem/yr (0.25 mSv/yr). Laboratory measurements are practical because site-specific dose modeling provides derived concentration limits for U-nat and Th-230

12 that can exceed current guideline values. For most sites, cleanup of soil U-nat and Th-230 would involve less than an acre (4,047 m2). Therefore, the costs of sampling and of laboratory analysis for these radionuciides would be a minor part of the decommissioning costs. Distinguishing in situ ore from processed ore material can be a problem on some sites and is addressed in the guidance. The NRC will regulate only NRG-licensed materials remaining at UR facilities, not in situ ore or mine waste. In determining compliance with the new regulation, the NRC staff will consider 10 CFR 40.420) and (k) that state, in part, that as a final step in decommissioning, the licensee shall demonstrate that the site is suitable for release and that reasonable effort has been made to eliminate residual radioactive contamination. C. Considerations of Risks. Costs, and Benefits of Cleanup Several commenters pointed out that the actual risk of excavating and moving dirt (construction and transport accident risks that are actuarial) must be compared against health risks of radiation exposure which have not been demonstrated below 10 rem/yr (0.1 Sv/yr). The risk of deaning up areas to below regional background levels would likely result in net human health and environmental detriment Lowering of the current radium standard for uranium and thorium could cause undue economic burden to industry and the Government based on the need for cleanup of large soil areas *and would not result in significant (if any) risk reduction. At ISL facilities, lowering dose criteria could result in large areas retroactively becoming disposal areas requiring substantial and costly cleanup, and could inhibit efficiency of mining if irrigation practices with restoration fluids were effectively prohibited.

13 C. Response: The NRC considered the risk of the cleanup work in the regulatory analysis. The radium standard is not lowered by the rulemaking; therefore, there is no undue economic burden for licensees. Providing a radium benchmark dose standard for U-nat and Th-230 should not result in significant decrease in the soil concentration allowed to remain, compared to current guidance. D. Regulatory Guidance Several commenters offered suggestions for regulatory guidance and requested that the regulatory guidance implementing the standard include determination of background and dose modeling flexibility. D. Response: The NRC recognizes that there may be difficulties in the determination of background concentrations of radionuciides at some UR facility sites. The NRC staff has prepared guidance (in the form of evaluation criteria} on mill site cleanup in the draft Standard Review Plan (SRP) for reclamation plans. This draft SRP will soon be published for public comment. The NRC staff is preparing another chapter of this SRP to address the implementation of the radium benchmark dose approach and dose modeling flexibility for this unique set of licensees. This chapter will also be published as a draft for public comment before finalization and incorporation into the SRP. IV. Agreement State Compatibility This rule will be a matter of compatibility between the NRC and the Agreement States, thereby providing consistency among State and Federal safety requirements. The final rule on

14 radiological criteria for license tennination for nuclear facilities issued July 21, 1997 (62 FR 39058), was determined to be a Division 2 matter of compatibility under the previous Commission policy for Agreement State compatibility. As noted for that final rule (at 62 FR 39079), Division 2 rules address basic principles of radiation safety and regulatory functions. Although Agreement States must address these principles in their regulations, the use of language identical to that in NRC rules is not necessary if the underlying principles are the same. Also, the Agreement States may adopt requirements more stringent than NRC rules. Under the current NRC policy, Category C compatibility would be consistent with that indicated in 62 FR 39079, and, hence, the NRC has detennined that this rule will be a Category C matter of compatibility. V. Finding of No Significant Environmental Impact: Availability The NRC has determined under the National Environmental Policy Act of 1969, as amended, and the regulations in Subpart A of 10 CFR Part 51, that this rule will not be a major Federal action significantly affecting the quality of the human environment and, therefore, an environmental impact statement is not required. The final rule amends the NRC's regulations in 1 0 CFR Part 40 to include radiological dose criteria for decommissioning of lands and structures at UR facilities. The rule will affect 11 current NRC licensees. The environmental impact of this rule will be insignificant compared to current practice and to the decommissioning process in general because the areas requiring cleanup for residual radionuclides other than radium are small. The final environmental assessment and finding of no significant impact on which this detennination is based are available for inspection in the NRC Public Document Room, 2120 L

15 Street NW (Lower Level), Washington, DC. Single copies of the environmental assessment and the finding of no significant environmental impact are available from Elaine Brummett, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Mailstop T7-J9, Washington, DC 20555-0001, telephone (301) 415-6066. VI. Paperwork Reduction Act Statement This final rule does not contain a new or amended information collection requirement subject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). Existing ~uirements were approved by the Office of Management and Budget, approval number 3150-0014. Public Protection Notification If an information collection does not display a currently valid 0MB control number, the NRC may not conduct or sponsor, and a person is not required to respond to, the information collection. VII. Regulatory Analysis The NRC has prepared a regulatory analysis on this final regulation. The analysis examines the costs and benefits of the alternatives considered by the NRC. The analysis is available for inspection in the NRC Public Document Room, 2120 L Street NW (Lower Level),

16 Washington, DC. Single copies of the analysis may be obtained from Frank Cardlle, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Mailstop T-C24, Washington, DC 20555-0001, telephone (301) 415-6185. VIII. Regulatory Flexibility Certification As required by the Regulatory Flexibility Act of 1980, 5 U.S.C. 605(b), the NRC certifies that this rule, if adopted, does not have a significant economic impact upon a substantial number of small entities. The rule will affect 11 current NRC licensees and any future licensees who will be conducting uranium milling operations. These licensees are not small entities as defined in 1 O CFR 2.81 O. IX. Backfit Analysis The NRC has determined that the backfrt rule, 1 O CFR 50.109, does not apply to this final rule and therefore, a backfit analysis Is not required for this final rule because these amendments do not involve reactor operations and do not involve any provisions that would impose backfits as defined in 10 CFR 50.109(a)(1). X. Small Business Regulatory Enforcement Fairness Act In accordance with the Small Business Regulatory Enforcement Fairness Act of 1996, the NRC has determined that this action is not a *major" rule and has verified this determination with the Office of Information and Regulatory Affairs, Office of Management and Budget.

17 XI. Criminal Penalties For the purposes of Section 223 of the Atomic Energy Act (AEA), the NRC is issuing the final rule under one or more of sections 161 b., 161 i, or 161 o of the AEA. Willful violations of the rule will be subject to criminal enforcement. List of Subjects 10 CFR Part 40 Criminal penalties, Government contracts, Hazardous materials transportation, Nuclear materials, Reporting and recordkeeping requirements, Source material, Uranium. For the reasons set out in the preamble and under the authority of the Atomic Energy Act of 1954, as amended; the Energy Reorganization Act of 1974, as amended; and 5 U.S.C. 552 and 553; the NRC is adopting the following amendments to 10 CFR Part 40. PART 40-DOMESTIC LICENSING OF SOURCE MATERIAL

1.

The authority citation for Part 40 continues to read as follows: Authority: Secs. 62, 63, 64, 65, 81, 161, 182, 183, 186, 68 Stat. 932,933, 935,948,953, 954,955, as amended, secs. 11e(2), 83, 84, Pub. L 95-604, 92 Stat 3033, as amended, 3039, sec. 234, 83 Stat. 444, as amended (42 U.S.C. 2014(e)(2), 2092, 2093, 2094, 2095, 2111, 2113, 2114, 2201, 2232, 2233, 2236, 2282); sec. 274, Pub. L. 86-373, 73 Stat. 688 (42 U.S.C. 2021); secs. 201, as amended, 202,206, 88 Stat. 1242, as amended, 1244, 1246 (42 U.S.C. 5841,

18 5842, 5846); sec. 275, 92 Stat 3021, as amended by Pub. L. 97-415, 96 Stal 2067 (42 U.S.C. 2022); 193, 104 Stat. 2835 as amended by Pub. L. 104-134, 110 Stat. 1321, 1321-349 (42 u.s.c. 2243). Section 40.7 also issued under Pub. L. 95-601, sec. 10, 92 Stat. 2951 (42 U.S.C. 5851). Section 40.31(g) also issued under sec. 122, 68 Stat. 939 {42 U.S.C. 2152). Section 40.46 also issued under sec. 184, 68 Stat. 954, as amended (42 U.S.C. 2234). Section 40.71 also issued under sec. 187, 68 Stat. 955 (42 U.S.C. 2237).

2.

In 1 0 CFR Part 40, Appendix A, Criterion 6(6), a second paragraph is added to read as follows: Byproduct material containing concentrations of radionuclides other than radium in soil, and surface activity on remaining structures, must not result in a total effective dose equivalent {TEDE) exceeding the dose from cleanup of radium contaminated soil to the above standard (benchmark dose), and must be at levels which are as low as is reasonably achievable. If more than one residual radionuclide is present in the same 100-square-meter area, the sum of the ratios for each radionuclide of concentration present to the concentration limit will not exceed *1" (unity). A calculation of the potential peak annual TEDE within 1000 years to the average member of the critical group that would result from applying the radium standard (not including radon) on the site must be submitted for approval. lhe use of decommissioning plans with benchmark doses which exceed 100 mrem/yr, before application of ALARA, requires the approval of the Commission after consideration of the recommendation of the NRC staff.

19 This requirement for dose criteria does not apply to sites that have decommissioning plans for soil and structures approved before the effective date of this rule. Dated at Rockville, Maryland, this ~ day of April 1999. For the Nuclear Regulatory Commission i ~iWLL.V:~-Sis= d Annette L Vietti-Cook, Secretary of the Commission.

F.A.C.T.S. (For A Clean Tonawanda Site) "PUTTING THE PIECES TOGETHE~ Box 566 'l:~o P~ ? Phone: (716) "S76-9552 Kenmore, NY 14217-0566 OFF/Cr,J:ax:,.., (716) 876-9552 R -

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'fr DOCKET NUMBER Ult;J!..,\\i/* ~ o' ADJUD/' 'J; T ,.~,~, v.,\\.,,.... 0TAFF PROPOSED RULE . Jort{O ( ~ :J. F ~ 3 Cf o 9 3) Secretary U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 (!j) February 10, 1998

Dear Rulemakings and Ad judications Staff:

Enclosed is a print copy of our comments on the proposed rule "Radiological Criteria for License Termination: Uranium Recovery Facilities". A copy of these comments was e-mailed to Ms. Charlene Raddatz earlier today. By telephone, I confirmed that she had received the comments, which she said woul d be entered into the docket before she l eft the office. We appreciate this opportunity to comment on this proposed rule at this late date. Sincere lb ~ 111.f\\~ 0 J ames M. Rauch FE8121998 Acknowledged by

U.S. NUCLEAR REGULATORY COMMISSION RULEMAKINGS & ADJUDICATIONS STAFF OFFICE OF THE SECRETARY OF THE COMMISSION Document S1atlstics Postmark oate

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Box 566 Kenmore, NY 14217-0566 F.A.C.T.S. (For A Clean Tonawanda Site) "PUTTING THE PIECES TOGETHER" Phone: (716) 876-9552 Fax: (716) 876-9552 Comments on U.S. Nuclear Regulatory Commission's Proposed Rule (62 FR 39093) "Radiological Criteria for License Termination: Uranium Recovery Facilities" James M. Rauch February 9, 1998

1)

As described (section II. Discussion), the proposed rule is unacceptable because the proposed criteria will result in doses in excess of the 100 millirem per year dose standard for protection of the public established in 10 CFR Part 20.

2)

The statement is made (section II. Discussion) that "per UMTRCA, the authority to set such cleanup standards for uranium mills rests with EPA." This statement is not completely correct. UMTRCA created a shared responsibility by both EPA and NRC for the management of 11.e.(2) byproduct materials. Section 84.a. of UMTRCA states, in part, "The Commission shall insure that the management of any such byproduct material, as defined in section lle.(2), is carried out in such manner as -- (1) the Commission deems appropriate to protect the public health an safety and the environment from radiological and non-radiological hazards associated with the processing and with the possession and transfer of such material." [emphasis added] This section of UMTRCA (Title II) resulted in NRC's promulgation of new 10 CFR 40 Section 40.2a (45 FR 65531, Oct. 3, 1980), subsection (b) of which states, in part, "The Commission will regulate byproduct material as defined in this part that is located at a site where milling operations are no longer active, if such site is not covered by the remedial action program of title I of the Uranium Mill Tailings Radiation Control Act of 1978." The fact that NRC has failed to regulate 11.e.(2) materials at many of these sites provides no justification for the currently proposed non-protective rule.

3)

UMTRCA was enacted by Congress as a direct result of serious radiation exposure problems which had developed in western communities at or near uranium processing operations. The acute problemSidentified were radon doses associated with the radium component of exposures to poorly managed uranium processing wastes. As a result, Title I of UMTRCA specifically designated twenty such sites for cleanup, and resulted in the EPA's 40 CFR 192 Title I radium standard [48 FR 602, Jan 5, 1983] (later duplicated for Title II sites [48 FR 45946, Oct 7, 1983]). The

stated dose basis for this radium standard is given as approximately 500 millirems per year, or a lifetime cancer risk of 0.02, or 1 in 50 (NRC's November 1992 "A Summary of NRC's Interim Radiological Cleanup Criteria and current Dose Bases"). This document also lists a RESRAD (default parameter) dose estimate of 260 mrem/yr. This is not a protective standard compared to the current 10 CFR 20's 100 millirem standard. In addition, EPA addressed only the radium component of these wastes, and neglected the uranium decay chains' other members, notably U-238, U-234, and Th-230, in effect creating a major regulatory gap for the significant doses from these other materials. In their comments on the proposed cleanup rule, members of the non-regulated community said that uranium/thorium mill disposal areas and soil cleanup at such sites should logically be included in the final rule, thereby closing this regulatory gap. Instead, NRC bowed to the wishes of the regulated community. NRC now seems intent upon further codifying these deficiencies.

4)

NRC had previously (October, 1981) adopted a "Branch Technical Position (BTP) on Disposal or Onsite Storage of Thorium or Uranium Wastes from Past Operations" (46 FR 52061), which addresses all uranium decay chain members and provides several management options. This 17 year-old BTP has been consistently applied at those sites listed in the SDMP. Option 1, the only currently available option for uranium sites (following the April 6, 1992 SRM), provides a 10 pCi/g total uranium guideline, equivalent to a 5 pCi/g level for Ra-226, Th-230, U-234, and u-238. In addition, NRC has consistently applied the Office of Nuclear Material Safety and Safeguards' Policy and Guidance Directive FC 83-23, which was released as a final rule on November 4, 1983 and which contains surface decontamination criteria and the BTP's soil cleanup guidelines. The provisions of the BTP and FC 83-23 should constitute NRC's minimum requirements for this proposed cleanup rule.

5)

The statement is made that "Calculations done by EPA in support of 40 CFR part 192 indicated that the dose from radium, excluding radon, was approximately 0.6 msv.yr (60 mrem/yr) (the final cleanup rule notes that doses from radon would be controlled by cleanup of radium which is the principal precursor to radon)." First, this 60 mrem/yr estimate is not in agreement with the stated dose basis or NRC RESRAD calculations noted above (comment 3). It is also not in agreement with an NRC staffers' calculations showing 200 mrem/yr using only the first 6 inches of soil at 5 pCi/g radium only (not a conservative assessment since significant dose may result from 15 pCi/g at deeper layers) and excluding radon dose. Please fully explain this discrepancy, if possible. Second, where does the final cleanup rule ("Radiological Criteria for License Termination") specifically state that radon doses will be included in demonstrating compliance with the dose standard? We have heard recent statements to the contrary.

6)

Radon doses are a major part of total dose from uranium processing materials. Radon doses attributable to 11.e.(2) materials should be included as a required element of complying with the 10 CFR 20 dose standard. If NRC disagrees, it must fully justify the exclusion of such radon doses. We are unaware that radon is specifically exempted from NRC regulation, please cite statute and section if NRC knows otherwise. The problem of radium ingrowth from parent chain members must be addressed, as the BTP approach does. The minimum timeframe for dose analysis should be 10,000 years since the longevity of the hazard from radium parents is virtually indefinite. Recognizing this duration of hazard issue, the Hanford EIS and the HLW repository EIS have adopted a 10,000 year timeframe. Even so, 10,000 years wi ll only cover ingrowth from Th-230 (which will peak at approximately 9000 years in the future).

7)

The proposed approach for this rule is unclear. It seems that the allowable dose from radionuclides other than radium must not exceed the dose from radium (using the 40 CFR 192 radium standard, which may be 200 mrem/yr or more, not including radon dose), but does not include the radium dose. Therefore, the total allowable dose would be twice the radium dose. Is this correct? Therefore, the total dose may exceed 400 mrem/yr, not including radon dose. See comment 1.

8)

NRC says that based on comments received on the proposed cleanup rule ("Radiological Criteria for License Termination") it decided to pursue this separate rulemaking for "uranium recovery facilities". What NRC does not say is that many comments were received from public interest groups and other regulators objecting to exempting facilities from the proposed cleanup rule. The comments favoring this alternate rulemaking came from the regulated community. Why did NRC choose to give this historically poorly-regulated community special treatment? NRC cites "unique decommissioning problems", but does not give any valid reasons for this special treatment other than to obliquely refer to the historic regulatory problems noted in our previous comments. This is no defense for this attempt to promulgate a rule that will not be protective of public health, i.e. that will not meet the 10 CFR Part 20 100 millirem dose standard.

9)

According to NRC staff there have been no comments from the public on this proposed rule. There have been only ten comments in all, two each from EPA and Illinois, and six from the regulated community. one reason for this may be that those who objected to special treatment for these facilities may have felt this rulemaking was a fait accompli, and therefore, that further comment was futile. Some may question NRC's usefulness as a regulator in this sphere, viewing this rulemaking as an example of NRC's willingness to participate in de facto self-regulation by these facilities.

10)

The specific areas of "uranium recovery facilities" which are to be covered by this rulemaking are identified in the notice

as "areas under mill buildings, in a yellow cake s t orage area, under/around an ore pad, and at ISLs [in situ leach] in soils where spray irrigation has occurred as a means of disposal". An NRC staffer has indicated that other areas, such as "windblown areas", may be included in the final rule. Any inclusion of areas other than as noticed would be an enl argement of scope and would require additional notice and review.

DOCKETED IJSHRC S't ~'F IL~~..... ~IS DEPARTMENT OF NUC r. AR SAFETY "97 DEC 23 A 8 :45 DOCKET PR-~~ aor10 ( /p:).F~ J'lo't 3) December 15, 1997 E 2704 Thomas W. Ortciger Director

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Radiological Criteria for License Termination: Uranium Recovery Facilitiel Dose Modeling Methods for Demonstration of Compliance. Regulatory Guide Development. Gentlemen: The Illinois Department of Nuclear Safety (Department) has submitted general comments regarding codification of dose objectives for certain radionuclides of concern in decontamination and decommissioning of uranium recovery facilities (letter dated October 6, 1997.) The Department hereby submits additional, more-specific technical comments regarding modeling parameters and pathways. One of the Department's primary concerns with the development of proposed regulatory guidance is the importance of retaining flexibility in the choice and implementation of dose model methodologies. The following comments serve to demonstrate the vagaries of modeling, and to request studious consideration of the modeling factors discussed. Please note that these comments are based, in part, on the Department's experience in licensing the decontamination and decommissioning of such a facility. To assess future exposure potential from a decommissioned uranium facility, radon and/ or thoron exposure must be evaluated. The interest in radon exposure in the past couple of decades has advanced our understanding of the factors that ultimately determine the potential for exposure and the resultant health effects. Thoron is less studied, and questions remain regarding the modeling of thoron dose. Flexibility in proposed regulatory modeling recommendations must be retained to permit inclusion of future enhancements. Some of the modeling factors of concern to the Department are discussed below. ,('("\\/clable

U.S. NUCLEAR REGUtATORY COMIMl~:>100 FU.EUAIQNGS &ADJ DICA STAFF a=RCE OF THE SECRETARY OFTI£ COMMISSI Ooclan8t1 Stallstk:s

U.S. Nuclear Regulatory Commission December 15, 1997 Dose Conversion Factor Page2 For the projection of dose from decommissioned uranium facilities, the use of alternative modeling parameters is not merely advisable, but necessary. To provide a reasonably valid projection, certain default modeling assumptions must be changed to properly evaluate pathway and exposure potential. Some of the available modeling software already allow, or take into account, these alternative parameters. The following quotes are taken from the manual for RESRAD, version 5.0, 1993; pp. 168-170: 11The ICRP-recommended dosimetric conversion factors are 1,000 mrem/WLM for radon-222 progeny and 350 mrem/WLM for radon-220 progeny [100% equilibrium ratios.] Because the environmental conditions in a mine and the physiological characteristics of miners are, respectively, significantly different from those in a home and members of the general public, the dose conversion factors (DCFs) derived for miners have to be extrapolated to the general population.... 11 11 *** 760 mrem/WLM for radon-222 progeny indoors. 11 11

• • .570 mrem/WLM for radon-222 outdoors.

11 "... 150 mrem/WLM... from exposure to radon-220 progeny indoors. 11 11

• • • 250 mrem/WLM for radon-220 outdoors."

[Note: The RESRAD dose conversion factors originate from the National Research Council companion study to BEIR IV, HComparative Dosimetry of Radon in Mines and Homes," National Academy Press, 1991.J Most people involved with radon/thoron dose modeling are familiar with these corrections for environmental conditions and breathing rates. There are other parameters which should be evaluated for extrapolation or adjustment to more appropriately model an exposure environment. Equilibrium Factor One of the most "adjustable II parameters is the equilibrium factor. The following is from "Scientific Basis for Risk Assessment & Management of Uranium Mill Tailings," National Research Council, National Academy Press, 1986,* pp. 84, 85 & 102: "The degree of equilibrium between radon and its daughter products is determined by a number of factors, including the length of time since the radon was released from the pile, the nature and concentration of aerosols in the air, and the nature and characteristics of the surfaces on which ions and particles may be lost by deposition. 11

U.S. Nuclear Regulatory Commission December 15, 1997 Page 3 "The 'equilibrium factor' [FJ is the ratio of the potential alpha dose for the daughter products in the air of interest-to the potential alpha dose for air in which the daughters are in [100%] equilibrium with radon.. " "... equilibrium factors vary considerably depending on a variety of environmental factors... from 0.3 to 0.6 for indoor air, from 0.5 to 0.8 for background outdoor air [away from piles], and from 0.005 to 0.1 for pile radon at the edge of the pile. 11 From these quotes, it is evident that a wide range of values for the equilibrium factor may be encountered. A licensee applying for decommissioning would be perfectly justified in the use of non-default or non-standard equilibrium factors. An agency evaluation of dose modeling submitted by the licensee should allow such corrections, as long as they can be* confirmed as appropriate. For the agency to confirm appropriateness, or to evaluate the licensee's evaluation of appropriateness, may take a lot of discussion and argument. It may be more effective to specify in the regulatory guide what equilibrium factors may be used, under what specific conditions. If a regulatory guide table or listing of acceptable "pre-evaluated" equilibrium factors is developed and incorporated to save time for licensees and regulatory evaluators,,it must include and allow the full range of potential* factor values, rather than merely the "typical" values. This is required to retain the necessary flexibility for modeling. Indoor Concentration One other adjustment that should be considered, but is often neglected, involves the "typical II recommended air concentration for thoron. Infiltration of radon and thoron into houses has historically been modeled as radionuclide entry into the house from the basement or from under the slab. The recommended indoor radon and thoron concentrations and dose-contnbutions assume "build-up," and are therefore typically higher than those recommended for outdoor exposure. Any modeling must take into account infiltration rates (turnover) and the time of day the most infiltration takes place, relative to corresponding occupancy times. From examination of available references, it is readily apparent how much the equilibrium factor can impact the estimation of dose. Unfortunately, these guidance documents were directed to the problem of radon and thoron infiltration from soils underneath a house, and assume that the gases seep into, and concentrate within, a house. In general, all published guidance assumes that indoor concentrations are greater than those outdoors. While natural seepage of radon from the soil may be the same outdoors and indoors, the outdoor gas is readily dispersed by air movement and is diluted by a large volume of air. The gas seeping into a house can not disperse, and is not diluted unless there is exchange with outside air. In addition, at reduced air exchange rates, "build-up" provides increased progeny equilibrium ratios. Conditions

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U.S. Nuclear Regulatory Commission December 15, 1997 Page4 which allow confined radon gas to be undisturbed permits the radon-daughter products to build to higher levels (relative to the radon parent nuclide.). The circumstances presented by the ev,aluation of residences adjacent to a clean-up site ( as opposed to houses located Ql1 decontaminated sub-soil) differ, in that indoor gas concentration is a dilution of outdoor gases which enter the house. There is little opportunity to become concentrated as described in the guidance documents. In the adjacent vicinity of the site, the initial gas concentration is outside the house, and only enters the house when air exchange is permitted through open doors and windows (and to a smaller degree by leaktzge.) The indoor radon concentrations are, therefore, more -likely to be comparable to, or lower than, outdoor concentrations - just the opposite of the projections presented in published guidance. Radon-progeny equilibrium factors of 50 % and 40 %, for indoor air, are the IDQfil quoted in published guidance, although 33 % is also often used. In the guides, 10% is generally used as the outdoor equilibrium factor. (Please note the apparent discrepancy in the outdoor factors quoted on the previous page, which demonstrates the variability of guidance provided by recommendation documents.) For thoron, 3 % (indoor) and 1 % (outdoor) equilibrium factors are used in the published guides. The short-lived daughter products of radon, Po-218, Pb-214, Bi-214, and Po-214, are of most significance for human exposure since it is these products which are inhaled and deliver the bronchial radiation dose that is implicated in bronchogenic carcinoma. The overall effective half-life for the sequence of the four daughters is about 30 minutes. When indoor radon is replenished from outdoor air exchange (as opposed to natural sub-soil seepage,) the relatively long 3.8-day half-life of radon and the short effective half-life of the daughters causes the indoor concentration of radon and progeny to be comparable to the outside concentration. In the case of thoron, the indoor concentrations are likely to be nrn.cil lower than outdoor concentrations. The "tightness II of the house, and the frequency and duration of opened doors and windows, will affect the air-exchange rate, and therefore, the indoor concentrations of thoron. Due to the fast decay of thoron (55. 6 seconds half-life,) its concentration indoors will diminish quickly after windows and doors are closed. The contribution to dose from indoor thoron progeny therefore diminishes to insignificance when compared to the radon progeny dose contribution. It is unreasonable to assume that thoron concentrations are higher inside the house relative to outside, as assumed in standard guidance recommendations. Assessments which include typical air exchange rates indicate that indoor thoron concentrations approximate 1125th (4%) of outdoor concentrations. For example, a measured 2.3 pCi/liter outdoor thoron concentration falls to 0.1 pCi/liter indoors. j

U.S. Nuclear Regulatory Commission December 15, 1997 Page5 Public Occupancy Factors The final factor that must be examined in estimating effective dose is the frequency and duration of occupancy in the locations of interest. Once the continuous-exposure dose has been estimated, adjustment for occupancy is a simple direct-ratio calculation. Highly-variable occupancy factor scenarios can be proposed and applied in modeling for the clean-up of a site. The following example is taken from a current Illinois cleanup site evaluation: Regulatory assumption Individual continuously "Present at site boun~, constantly exposed to, and inhaling radionuclide air concentration. EA assumptions Observed actuality Example Evaluation Department environmental assessment modeling and calculations assumed an individual observer would be present at the fenceline boundary for two hours a day. In addition to fhis assumed fenceline observer presence, the nearest resident was also assumed to be outside for 14 hours per week. An indoor occupancy of 18 hours/day was assumed. (The EPA asswnes outdoor occupancy is 3 hours per week.) Department inspectors report that fenceline observers are extremely rare, and were present for minutes, rather than hours. Persons have been observed walking down the street, or working and playing in their yards. The time spent outside by the nearest residents, averaged over the year, appeared to be better characterized by the BP A's assumption of 3 hours per week, rather than 14 hours per week. The example table on the following page, from the site evaluation mentioned above, demonstrates issues covered so far, including conservative occupancy factors, measured gas concentrations, and equilibrium factors.

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U.S. Nuclear Regulatory Commission December 15, 1997 Avera2e Concentration (pCi/liter) Household Air Exchange (per hour) Radionuclide Half-life (hours) Indoor Dilution Factor Airborne Concentration (pCi/liter) Progeny Eauilibrium ( % } pCi/liter rer WL Working Levels (WL) WLMs ner 1 WL-vear Exoosure (WLM) DCF (mrem/WLM) Continuous-Ex:oosure Dose (mrem) Time Exposed (hr/dav} Occupancy Factor Projected Dose (mrem) Radon Outdoors 0.23 0.23 10 '* 1,000 0.00023 51.5 0.012 570 6.8 2 1/12 0.6 Page6 Radon Thoron Thoron Indoors Outdoors Indoors 2.3 2 2 91.7 0.0154 1.0 0.043 0.23 2.3 0.1 50 1 3 200 750 250 0.0012 0.0031 0.0004 51.5 51.5 51.5 0.062 0.16 0.021 760 250 150 47.1 40.0 3.2 18 2 18 3/4 1/12 3/4 35.3 3.3 2.4 Radon/Thoron Effective Dose Equivalent (EDE) for Year (mrem) 41.6 The factors presented in this example have values typical of those in published guidance. Recommended factors are intentionally conservative, and thereby slightly overestimate dose. Whenever assumptions had to be made regarding values to be factored into the estimate, a realistic, yet conservative, value was chosen to ensure that any error in the assumption would not result in an underestimation of the exposure. This dose estimate can be considered comparable to, or higher than, dose estimates from more exhaustive calculations. In this specific case, the licensee used lower progeny equilibrium factors in their dose estimates - factors which may indeed be appropriate. Their dose estimates are therefore lower than the final estimate above. Many other adjustments could have been incorporated into this exposure analysis, further refining the dose estimate. For example, diurnal maximum concentrations occur at night and in early morning hours when the atmosphere is stable. Minima occur in the afternoons when atmospheric mixing is at maximum. This analysis did not consider the reduced exposure resulting from the typical trend of houses being "closed-up" at night (during maxima) and more open in the daytime (during minima.) This will, of course, also vary depending on the region of the country, season, air conditioning, open windows at night, etc. Much more detailed data would have to be collected to assess the diurnal correlation between

U.S. Nuclear Regulatory Commission December 15, 1997 Page 7 cleanup activities, post-cleanup conditions, and maximum and minimum radon/thoron air concentrations. Conclusion Anyone familiarizing themselves with the interrelation of all of the various conditions and resultant parameters will quickly see that the final dose assessment will heavily depend on the parameters chosen. Any proposed regulatory guide should include allowances for existent variabilities, and clearly distinguish when and what alternative parameters are acceptable. Of primary interest to the Department is that neither the licensee nor the regulator be unfairly restricted from justifiably using alternate parameters when appropriate and necessary. As stated in previous comments, the Department encourages the use of dose-objective standards, and the development of regulatory guidance for dose-modeling to establish radiological criteria for license tennination. The Department's agreement with this approach is, however, highly dependent on the maintenance of flexibility in the proposed guidance. Thank you for the opportunity to comment further on this issue. If you have any questions regarding these comments, please contact me at (217)785-9947. JGK:DSP Sincerely, ph . Klinger, Chief sion of Radioactive Ma

U.S. Nuclear Regulatory Commission December 15, 1997 Additional References Page 8 Clarke, Roger H. "ICRP Recommendations Applicable to the Mining and Minerals Processing Industries and to Natural Sourcesn Health Physics 69(4):454-460; 1995. Federal Guidance Report No. 11, "Limiting Values of Radionuclide Intake and Air Concentration and Dose Conversion Factors for Inhalation, Submersion, and Ingestion* (reprinted by the EPA as EPA-520/1-88-020, September 1988.) BEIR IV, "Health Risks of Radon and Other Internally-Deposited Alpha-Emitters," National Research Council, 1988. NCRP Report No. 77, "Exposures From the Uranium Series with Emphasis on Radon and its Daughters," issued March 15, 1984. NCRP Report No. 78, nEvaluation of Occupational and Environmental Exposures to Radon and Radon Daughters in the United States," issued May 31, 1984. NCRP Report No. 94, nExposure of the Population in the United States and Canada from Natural Backgrounq Radiation," issued December 30, 1987. NCRP Report No. 97, "Measurement of Radon and Radon Daughters in Air," issued November 15, 1988.

Frank Cardile UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460 NOV 2 8 1997 DOCKETED USNRC "97 OEC 18 A11 :5 7 Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 DOCKET NlllBERPII PROPOSED RULE ~ 0 J- '1,0

Dear Mr. Cardile:

( 0, F~ 3 CJD93 This letter is in response to the Nuclear Regulatory Commission (NRC) request for additional comment on the Radiological Criteria for License Termination: Uranium Recovery Facilities (Federal Register Vol. 62. No. 139). The July 21, 1997 request for comment states that "EPA in support of 40 CFR part 192 indicated that the dose from radium, excluding radon, was approximately.6 mSv/yr (60 mrem/yr)". EPA would like to clarify this statement. On page 47 of the Final Environmental Impact Statement for Remedial Action Standards for Inactive Uranium Processing Sites ( 40 CFR 192), October 1982, EPA states the following: "Natural or contaminated soils with radium concentrations of 5 pCi/g through a depth of several feet can produce gamma radiation exposure rates of about 80 mrem/y (NP76). Exposure rates are proportionately higher or lower for other radium concentrations and decrease as the layer of radium-contaminated material becomes thinner or is covered over by other materials." In this statement EPA is referring to a maximum dose rate which does not include other assumptions such as structural shielding and occupancy time. Realistic usage scenarios for residential use, and certainly those for more restrictive uses, will therefore result in significantly lower values than the continuous unshielded dose rate. The enclosed EPA report, "Reassessment of Radium and Thorium Soil Concentrations and Annual Dose Rates", July 22, 1996, demonstrates this. Results from this report indicate that the dose from 5 pCi/g in the top 15 cm is consistent with the minimally acceptable dose limit of 15 mrem/yr EDE under a residential exposure scenario for radium-226 or radium-228. Similarly the report shows that under these conditions thorium-232 or thorium-230 is also consistent with the minimally acceptable dose limit. For land uses other than residential (e.g., commercial/industrial, recreational) the UMTRCA cleanup standards are more stringent in that they correspond to a dose that is significantly less than 15 mrem/yr for all four radionuclides. OEC l 9 1997 Aclcnowtedged by card.......,,..,n,v::nocv t

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U.S. NUCLEAR REGULATORY~ RULEMAKINGS & ADJUDICATIONS ST~ OFFICE OF THE SECRETARY OF THE COMMISSION DocumentStalilllcl Postmark Date ~~~!1.L..-=-T----"-=~ "~ )eAwaidf c 1' I :J pf /,1 Copies Add'I s

NRC's request for additional comment Federal Register notice also refers to a lack of suitable cleanup criteria for uranium or thorium: "Because 10 CFR Part 40, Appendix A, does not codify cleanup criteria for soil contamination from radionuclides other than radium, it cannot be used as a standard for uranill!Il and thorium cleanup." Please note that under Subpart E of 40 CFR Part 192 ( 48 FR 45947), Standards for Management -of Thorium Byproduct Materials Pursuant to Section 84 of the Atomic Energy Act of 1954, as Amended, EPA determined that its 5 pCi/g and 15 pCi/g standards were suitable for remediation of thorium byproduct material (radium-228) at Title II sites that are operated by NRC or Agreement State licensees (see 48 FR 45944 and the FEIS fpr Standards for the Control of Byproduct Materials from Uranium Ore Processing (40 CFR 192) Volume I, Appendix G: Thorium Mill Tailings). Although these standards and those in Subpart D of 40 CFR Part 192 were developed for different radioisotopes, and were applicabl~ to two different sets of UMTRCA sites, both standards are based upon the risk from gamma exposure. In addition, in order to meet a permanent clean-up objective for radium-226 and radium-228, there needs to be reasonable assurance that the preceding radionuclides in the series will not be left behind at levels that will permit radium to build-up to levels exceeding 5 pCi/g during the period of concern. For further discussion on these standards and risks, see the enclosed memorandum from Margo T. Oge, Director Office of Radiation and Inc,loor Air to David Kee, Director Air and Radiation Division Region 5 entitled "Technical Input on Cleanup Criteria for West Chicago, IL., Residential Area Superfund Site," June 18, 1993. I IfNRC were to develop a dose limit cleanup standard for uranium, EPA' s position would continue to be that for a dose limit to be considered protective of human health, it should be no greater than 15 mrem/yr. Dose limits higher than 15 mrem/yr are beyond the upper bound of the risk range generally considered protective under CERCLA In addition, they present risks that are higher than levels EPA has found to be protective for carcinogens in general and for radiation, in particular, in other contexts. For an explanation of why this dose limit is protective of human health for cleanups of radioactively contaminated sites, see Attachment B: Analysis of what Radiation Dose Limit is Protective of Human Health at CERCLA Sites (Including Review of Dose Limits in NRC Decommissioning Rule) which is attached to the EPA guidance document , &tablishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination, (OSWER Directive No. 9200.4-18), August 22, 1997. If we can be of any additional assistance, please call me at (202) 564-9382. Sincerely, ~s.Q~~ John M. Karhnak, Director Center for Cleanup and Reuse l

Reassessment of Radium and Thorium Soil Concentrations and Annual Dose Rates U.S. Environmental Protection AgcnC) Office of Radiation and Indoor Air 401 M Street, SW. Washington, D.C. 20460 July 22, 1996 EPA's Office of Radiation and Indoor Air (ORIA) is reviewing key modeling assumptions and parameter values used in the Agency's draft Technical Support Document (TSD)1 to calculate radiation doses and radionuclide soil concentrations. The scope of this review includes exposure scenarios based on current and future land use after cleanup, generic model site characteristics, and standardized defoult,exposure factors. ORIA is particularly interested in choosing modeling assumptions that are "realistic" or '*reasonable," based on site-specific information, yet fully protective of human health and the environment. This paper presents the results of a focused reassessment of derived -soil concentrations and associated annual dose rates for selected isotopes of radium (Ra-226 and Ra-228) and-thoril!m (Th-230 and , Th-232) conducted by ORIA as part of its overall review. The primary purpose of this evaluation was to assess generically dose rate levels that correspond to the 5 picocuric per gram (pCi/g) soil cleanup concentration spcc11ied under 40 CFR 1921 for uranium and thorium mill tailings sites This reassessment \\\\as conducted by comparing radium and thonurn doses and soil concentrations calculated assuming a contaminated zone area and thickness for the model site described in the AgcnC)**s drafi TSD \\\\ith those. computed assuming different dimensions specified under 40 CFR 192. Secondary. goals or Lhc reassessment were to calculat(? radium and thorium doses and soil concentrations for two new recreational exposure scenarios and for reduced gamma shielding and soil-to-plant transfer factors.

Background

Chapter 2 of the draft TSD describes the exposure scenarios used by EPA in the proposed soil cleanup rule analyses to calculate individual radiation doses and risks, und Chap_ter 3 presents *a detailed discussion of the default exposure parameters and model site characteristics used to derive radionuclide-specific soil concentrations corresponding to target dose and risklim1ts. As explained in these two chapters, ORIA selected these exposure scenarios, default parameters, and model site characteristics for several reasons, including consistency and compatibility with current Agency guidance. 1 Uad,allon Site Cleanup Regulatiom: Tt!clmical Support Doc11me111 for the Develop111e11t of Rmlio1111clide ( '/emmp /-'-*1*e/.\\ for Sm/ (Re\\'lt,'\\\\' Droll). EPA 402-R-96-011 A, 8, and C Ollke of /\\tr ar J Ru<ltut1rn1. S1..1lt 1994 2 I tile --10 or th..: l'o<l..: or F..:u..:rul R..:gulottons, Port 192-Hea/tl, Cllld b1v1m11111e111al I 'mft*t /IOI/,\\ 0/t111darr.l., for ( m,1111111 t111:,t l J S En\\'lronnK111ul Proll!Clton /\\gene~ --IX I* R (l02. Jan 5. I *~Xl (S1..'I! s1lel!1licull~ ~ I ')2 12 ) Th..: h..:nlth un<l em*1ronmcntol proll!Ctton stan<lanJs SI..'! forth 111 40 l'FR I 'J2 ar..: som1..'\\1m1..-;; rdi!rrcd to us **UMTRl'A ston<lanJ.._** hosed on the Uranium Mill Tailmgs Ro<lml1011 Control Act *or I '>78, Puh L 95-604. as amended. that authorlZ.tXl and directed EPA to estahlish the Port 192 :.1on<lnrds

--reasonableness., with respect to intended land use and assumed exposure pathways after cleanup, and --representativeness" with respect to the characteristics of real and reference rad.Jabon sites. Overall, the assumptions used in the TSD to model radiation doses and nsks are.. conservatlve" in the sense that their use will, in the vast maJority of cases, overestimate the true doses and risks posed by radionucl1des at specific sites The selection of conservative assumptions was deemed necessary by EPA to capture the full spectrum of possible doses and nsks associated with th~ diverse and lughly complex universe of known and potential f ulure radiation sites. Since the publication of the draft TSD in 1994, ORJA has revised several or 1ls earlier calculations and conducted nc,, cvalµations. Much of this effort has focused on rcc:\\.am111ing the.. reasonableness** and

• • reprcscntativencss** of modeling assW11ptions. Current evaluations. mcludmg those presented 111 this paper.

are directed to\\\\ard refining assumptions and analyses based on s1le-spccific infonnal1on Calculations Three sets of calculations were performed to derive the soil concentrations and associated annual dose rates for selected isotopes of radium and thorium presented in Attachment 1. The first set of calculations-labeled TSD" in Attachment I-compares soil concentrations and dose rates presented in the draft TSD for rural residential, suburban residential, and commercial/industrial exposure scenarios3, with comparable values derived for two new recreational exposure scenarios, playground and hunter/fisher. Under the proposed radiation site cleanup regulations, recreational scenarios like these might be recommended by the Agency for use in evaluating sites transferred (or leased) from one federal agency to another after cleanup. For calculations of radium and thonum doses and soil concentrations, both,recreatlonal scenarios assume all , of the default exposure factors for rural residential exposures provided in ihe draft TSD, except as indicated m Attachment 2. The second set of calculallons-labeled "Calculation A** in Attachment I-refer Lo the scenario based on 40 CFR 192 comparison. In this analysis. radium soil concenlrall~ns and doses,,ere compuled assuming a contaminated,..one area of l 00 m~ and thickness of 0.15 m. as specified under 40 CFR 192 These results can be compared with those derived using the TSD dcfaulls or I ().000 m~ and 2 m. respectively As used m-40 CFR 192. the l00 m:: area reprcscnls a typical sur\\'cy unil su.c. and the 0.15 m Ll11ckncss represents sites contaminated with wmdblO\\vn uranium, radium, and thonum tailings Further as shown in Table 3-12 (p. 3-41) of the draft TSD, 50% of the reference sites considered in the TSD analyses had a contaminated wne thickness of about 0.15 m or less prior to remediation. Aft.er remediabon. this percentage would be expected to mcrease. In a general sense, the Calculation A assessment is a focused sensitivity analysis to detennine the effect of vaiying contaminated zone area and thickness simultaneously on derived soil concentrations and \\ associated radiation dose rates. [The effect of varying these parameters individually is discussed in detail in '\\ TSD Chapter 3 ] The third set of calculations-labeled "Calculation B" in Attachment 1-are based on the 40 CFR 192 assumptions in Calculation A and on three additional modifications: (I) the gamma shielding factor (i.e., the ratio of indoor to outdoor gamma exposure rates) was assumed to be 0.4 (60% slueldmg), mstead of the TSD default value of 0 8 (20%), (2) the soil-to-plant transfer factor for rndmm was assumed to be 7 14E-03, ' St.:..: TSI) *1 uhk.-:- 3-1. 3-2 an<l 3-3 (pp. 3-4 through 3-9) and Tuhl~ 7-1 (pp 7-4 through 7-1, l 2

mstead or the TSD default value of 4.0E-02, and (3) the soil-to-plant transfer factor for lead (1 e. Pb-210, n radioactl\\*e decay product ofRa-226) was assumed to be l.55E-03. instead of the TSD default value of l.OE-02 The Cnlculat10n B assessment investigated the effects of deriving soil concentrations based on values for the gamma shieldmg factor and radium and lead plant transfer factors that are different from. and possibly more nppropnate than. the default values m the draft TSD. The modified par neter values used in this assessment are based on a recent review of the literature.4 This review found that gamma slueldmg factors typically range from 0.4 (60% shielding) for above ground, lightly constructed (wood frame) homes to 0.2 (80% shieldmg) for bnck homes. Based on this infonnation, the review suggested that a default gamma shielding factor of O 4 might be a more appropriate value to use at sites with soil contammated with radionuclides than the current EPA default of 0.85 (20% shielding) In addition, 0.4 is comparable to the value of O 33 (67% shielding) used by the Nuclear Regulatory Commission (NRC). 6 The review also concluded that recent scientific studies support revised sod-to-plant transfer factors of 7 I 4E-03 for radium and 1 55E-03 for lead-compared to the drafi TSD values of 4.0E-02 and I.0E-2. rcspccll\\*cly. which are the default Yalucs provided m RESRAD. All calculallons locus on Ra-226. Ra-2i8. Th-230 and Th-232. rad1onuchdcs that occur frequently at sites. subJiXl lo EPA* s proposed cleanup regulations and lo 40 CFR 192. As mentioned prn, iousl~. soil concentration data for Lhc rural residential. suburban residential, and commercial/industrial exposure scenanos were taken from the draft TSD (Table 7-1). Soil data for the two new recreational exposure scenanos were calculated using RESRAD Version 5.61 assuming the parameter values shown in Attachment 2 Results The results of the three calculntional sets are presented in Attachment l and discussed below. Results of the TSD Calculations As shown under the headmg --rsD" of Attachment l, soil concentrations for all radium and thorium isotopes computed using the two new recreational scenarios are much higher than sirrularly derived values usmg the rural residential. suburban residential, and commercial/industnnl exposure scenarios described in the draft TS D -l :--unmum/,:d m a m'-"lllOI unJum, Reaue.u111e11/ of the Denved ( '011c,e111m1w11 ( i11ulel111e !... wl for Rac/111m 111 Soil. dah:d 111 Januar'.\\ 19% lo 11 lk"llJamm Hull (EP /\\-ORIA) from John Muw o (SC&/\\) \\* 5 EPA*:,; cum:111 ganuna sludJmg factor value of0.8 1s based on infonnot10n pre.~ente<l m two Agency reports, Natural Radia//0111111/ie Umted States (ORP/SID 72-1 ~ Oakley 1972) and Pop11/a11011 Er:posure to Ewemal Natural Radial.Ion Background m the Umted States (ORP/SEPD-80-12; Bogen and Goldm 1981) EPA adopted 0.8 as the default vnlue for the gamma sh1eldmg factor used in the development of nsk-bnsed prehminnry remeJ1ation goals for radmnuchJes discussed in Part B of the Risk Assessment Guidance for Supe,f,md (EP A/540/R-92/003. December 1991 ). 6 ReMdual Radioactive Co11ta111111a11011 Fmm Deco111111iss1011111g: Tecl1111cal Bas,sjor Translatmg ( '0111a11111111110n Levels 10 A111111al Total Ejfecuve Dose £q111vale11t, Fmal Repor/ NUREG/CR-5512 PNL-7994, Volumo:: I Nuclear Regulotorv Comnm,,;1on June 1994 3

\\ Rcsulls or lhc Calculat1on A Analvsis Comparing the rcsulLs of the TSO calculations with the Calculation A analysis sho\\\\s thal-for Ra-226. Ra-22M. and Th-232-{hc TSO soil concentrations yielding an annual dose or 15 mrcm EDE mcrcasc by a factor or 1-4. This mcrcasc rcsulLs from simultaneously dccrcasmg the contammalcd 1:onc area from th(? TSD default by factor of 100 (i.e., from 10.000 m~ Lo l 00 m~) and decreased 111 thickness b~ a factor of 13 (i.e.. fro*, 2 m to 0.15 m). Similarly, the results for the same radionuclidcs show that the annual dose rates for these rad1onuclides (except Th-230) nt individual concentrations of 5 pCi/g m sotl range from 2-25 mrem/yr EDE (cohmm 7) for the Calculation A assumptions compared with 2-75 mrem/)T EDE based on the TSO defaults (column 6). The effects on Th-230 soil concentrations and dose rates are even more pronounced and are discussed below. The bases for the Ra-226, Ra-228, and Th-232 results are readily explained. As shown in Table 3-1 (pp. 3-5 and 3-6) of the draft TSO, the doses from these radionuclides are almost entirely due to the external gamma radtation and plant pathways (excluding the radon pathway). Decreasing the thickness of the contaminated zone from 2 m to 0.15 m decreases the dose from the external pathway because the contribution to the gamma radiation field from radionuclides buried below 0.15 m is eliminated Since RESRAD models a root zone depth of O. 9 m throughout wliich rndionuclides are assumed to be absorbed, decreasing the thickness of the contanunnted zone also reduces the amounts of rndionuclides taken up by plants. Reducing the contammated area reduces how much produce is grown onsite and mgested b~~ individuals living on the site. In summary. by reducing the contaminated zone iu-ea and thickness-whiah in tum decreases the dose contributions from the external nod plant pathways-the individual soil concentrations for Ra-226. Ra-228, and Th-232 yielding a dose rate of 15 mrcm/yr EDE increase, although not m direct proportion lo the changes in the contaminated.One an::a and thickness. For Th-230. Lhc results arc not as cusily explained. As sho\\\\11 m Table 3-1 or the drall TSD. the dose from Th-230 in soil (excluding* the radon pathway) is due primarily to the external (70%) and plant (25%) pathways. and the maximwn dose rate occurs in year 1,000 Since Th-230 is essentially a pure aJpha-emitter, the external dose contribution (and most of the plant pathway contnbutiori) for this nuclide is due to the mgrowth of Ra-226 and progeny over the l,QOO year time ~- This is possible because, over this time frame,* the anlOUllt of radmm and decay products produced and present in soil is greater than the amount of radium and thorium removed from soil by erosion and leaching. However. when the contaminated zone thickness is reduced to 0.15 m, the source erosion rate (0.001 m/yr) effectively removes the Th-230 faster_ than the time required for Ra-226 and progeny to grow in. Hence, the external and plant pathway doses from Th-230 are greatly reduced, and the mnximwn dose rate occurs at time zero. In summary. reducing the truckness of the contaminated zone for Th-230 effectively eliminates the ingrowth of Ra-226 plus progeny, wtuch m turn greatly diminishes the dose contributions from the external and plant pathways. As a result, the soil concentration for Th-230 yielding a dose rate of 15 mrem/yr EDE increases by a factor of 21-43 (compare columns 3 and 4) when the soil thickness is reduced by a factor of 13 (i.e. from 2 m to 0.15 m). Results or the Calculation B Analvsis The results of lhc Calculation B analysis are largely similar to those described abO\\ e for the Calculallon A assessment. This finding is in keeping with the fact that the two assessments arc based on most of th~ same assumptions. including the reduced contaminated zone* area and thickness The further increase m the soil concentrations by a factor of approximately _two for all radionuclides (e.... cept Th-230) listed under Calculation B compared \\\\'ilh those under Calculation A 1s d1rcctl~ proportional to the reduction m the gamma shielding factor by a factor of 2 (i.e., from 0.8 lo 0.4). For 1h-230. the increase m soil concentrations from Calculation A to Calculation B is due to a combinalton of effects (i.e.. the reduction in the gamma shielding factor and the modifications in the plant transfer factors for rndnun and lead). 4

Conclusions This paper presents the results of a focused reassessment of derived soil concentrations and associated annual dose rates for selected isotopes of radium (Ra-226 and R.a-228) and thorium (Th-230 and Th-232) listed m 40 CFR l 92. When examming sites cleaned up under 40 CFR l 92. the Pml 192 standards are generally comparable to the proposed 40 CFR 196 cleanup rule standard of 15 mrem/yr for R.a-226, Ra-228. and Th-232. and much more stringent for Th-230 For land uses other ~.. an residential. the Part 192 sland~rds arc more strmgcnt than the proposed Part I 96 standard. To further correlate the cleanup conccnlrat1ons at a particular UMTRCA, site to a dose level would require a s1tc-spccilic dctcnnmation that would Lake mto consideration the physical characteristics of the site ns well as the proJcctcd land use EPA anticipates that these s1tc-spcc1fic analyses would indicate that UMTRCA cleanups nught result in lo\\\\cr -actual dose rates than those calculated in the analyses presented m this paper 5

Attachment l. Radium and Thorium Soil Concentrations and Doses Concentration (pCl/g) in soil Annual Dose Rate (mrem/yr EDE) yielding 15 mrenvyr EDE Corresponding to II pCllg in son ca1cu1ation calculation Calculatlon

• Calculation NucHde Exposure scenario TSDt A*

B** T';;D A* B** Ra-226 Rural Residential . 1 4 811 75 19 9 Suburban R88ldentJal 1 4 811 75 19 9 Commercral/lndustrlal 5 11 20 15 7 4 Recreational Playgroond 28 39 39 3 2 2 Recreational Hunter/Fisher 18 26 30 4 3 3 Ra-228 Rural Reaidertlal 2 5 9 38 15 8 Suborban Restdenttal 2 5 9 38 15 8 CommerC181/lndustnal 6 13 23 13 6 3 Recreabonal Pla)<ground 33 47 47 2 2 2 Recreational Hunter/Fisher 21 31 36 4 2 2 To-230 RuralResidentlal 3 123 151 25 06 0.5 SUbYfban Residential 5 215 409 15 0.3 0.2 Commeroial/lndustrlal 16 333 406 5 0.2 0.2 Recreational Playground 94 1,737 1,737 0.8 0.04 0.04 Recreational Hunter/Fisher 62 1,310 1,502 1 0:.1 0.05 To-232 Rural R881dentlal 1 3 5 75 25 15 Suburban Residential 1 3 7 75 25 11 CommefclSVlndustnal 3 8 15 25 9 5 Recreational Playground 19 33 33 4 2 2 RecreatlOlllll Hunter/Fi&her 13 22 26 6 3 3 t Soll concentration data for the rural reaidentlal, suburban realdenbal, and commercial/1ndusbial exposure scenarios are taken from Table 7-1 {pp. 7-4 through 7-6) of the draft TSO Data for the recreational playground and hunter/fisher scenarios are~ provided tn draft TSO, they were calculated USll1Q RESRAO Version 5 61 and the exp08Ul'e factors In Attactvnent 2, as discussed in the text

• Assumes all TSO default exposure parameter values fQr each resped!ve ~

for a model site, except. the conlamtnated zone area Is 88Sllmed to be 100 m2, Instead of the TSD value of 10,000 m2 the contaminated zone thickness is assumed to be O 15 m, Instead of the TSO value of 2 m. .. Same assumpttoos as 1n calculation A, plus: the gamma shielding factor is assumed to be 04 (80%), instead of the TSO value of 0.8 {2()%) the solJ..to..plant transfer factor for Ra-2261& 8ULIJl6d to be 7.14E-03, Instead of the TSO value of 4.0E-02 the soil-to-plant traMfer factor for Pb-210 Is assumed to be 1.SSE-03, lnatead of the TSO value of 1.0E-02 ,i Given the same assumptions at11n calcliation 8, except that the contaminated zone is asaumed to be equal to a typ;cal O 5--acre (2,023 m2) lot SlZ8 and that the contaminated zone thlcknesa Is aSSllTled to be 0.3 m, the soil eoncentratton fOf Ra-226 yielding 15 mrem/yr EDE rs abol.t 5 pCl/g for both the rural residential and subufban residenbal exposure scenarios 6 . Exposure Parameter Values for the Recreational Playground and Hunter/Fisher Scenarios* Parameter Recreational Playground Scenario Recreational Hunter/Rsher Scenario Exposure pathways 1 External racbahon exposure 1 External racballon exposure 2 lnhalabon of contaminated dust 2 lnhalahon of contaminated dust 3 lngestlOl'l of contaminated dnnkmg water 3 Ingestion of contaminated dnnkmg water

4. Ingestion of contaminated soil 4 Ingestion of contaminated sod 5 Ingestion of contaminated meat 6 Ingestion of contaminated frsh Exposure frequency 140 d/y 30d/y (1.e., 5 d/wk x 4 wk/mo x 7 mo/y)

(] e, 1 mo/y) Exposure time 3 hid outdoors, o hid indoors 16 hid outdoors; 8 hid indoors lnhalabon rate 1,540 m3/y 600 m3/y (1.e., 11 m3/d of contaminated dust x 140 d/y) (1 e., 20 m3/d of contaminated dl.lSt x 30 d/y) Drinking water rate 140L/y 60 Uy (Le., 1 Ud of contaminated water x 140 d/y) (1.e, 2 Ud of contammated water x 30 d/y) Meat mgesllO/'l rate Not applicable 2 25 kg/y (1.e, 0 075kg/d X 30 d/y) Fish tngesbon rate Not applicable 1 62 kg/y (1.e

• 0 054 kg/d x 30 d/y)

Indoor/outdoor lnhalat10n Not appllcable 0 8 (20% shielding) shieldmg factor Feed storage limes Not applicable 0 days

• All other parameter values not shown are Identical to those spec:1fied Ill the draft TSO for the rural residential exposure scenario using the RESRAD computer code 7

UNITED STATES ENV1RONMENTAL PROTECTION AGeJCV WASHINGTON, O.C. 20460 Of'C!Cli 0i: ,\\JII AAIO ~110N MlQIOBMpOH

SUBJECT:

Technical Input on Cleanup Criteria for West Chic.iqo, :IL, Re.Sid.ential Area. Superfund Site FRON: llargo T.. OCJe,

• Direct:"'..A (\\

Office* of Jta41aticm d ~oor Air (6601J) TO: David ICM, Director Air and Radiation Division, Region 5 (SA-26) '!his is in responact to yaa.:r lett:ar of Kay 10, 1993, requesting the Office or Radiation and Indoor Air'* (ORIA) inplt on three specific issuea related to Clean-up crit.ria at tbe Jfest Chicago Residential, Area National Priority List (!IPL) site. ORI.l's criteria and standarda Division end ltad.16tion Studiaa Division bav. raviawed these iaauaa and offer the follQllling cona1darati0b8:

1.

Rogion s aaked if - clean-up level o~ J.5 pci/g for Ra.-~28 slloold be considered instead of 5 pCi/g, based on its 9uaa dose rate being 1.4 tblee greater than tbat for Ra-226. when. the default: occapanoy and shielding factors and the finite extent or these conta:ai.nat.M area& are taken into account, tbe risk n:oa ~1 9._ racliation troa b.-226 or 1ta-a2e at a either of thHa levels is anticiHted to be in t:he SUper~unc:I

• target rist nnge (i.e. al:>>ou.t 10 -4).,

Also, in fQ CfR i,2. Su.bgart I!, tb.- tvo iaotopu are treated aa *illlilar hazards. Therefore. considering tbe uncartainti** in risk aaa.acll8nt calculation*, ve cannot offer.a strong technical. argaJMnt for one of these l.,,.els over the other.

2. Region s asked if an indoor thoron liai t ot. o.. 1 WL ahould be conaiderecl imatea4 of 0.02 VL.

In 40 Cf& 192. S>>,),.part; I, Rn-320 i* ~l.lod at tbe.... level u an-222 \\'*, (i.e., at o. 02 WL)

• Bowever, the controlling hazard in this application is gamaa radiation troa Ra-22a, and,. for indoor airf rad.on, not 'Choron, l* the critical iaot.ope.

'l'bereforer for prt1eUcal reasons, 'there does no't. appear to be any coapell1ng reason t.o IIOd.1:fY the 0.02 WL llait. tor coabined raclon and. thoron in this application.

3.

Regions baa specified a soil li:ait of 5 pCi/9 above baekgrumd and aalts if it is correct to apply tbi,.. l.blit, ae they nav*, to total radium. OIUA agrees that it is appropriate to ccmbine tba ac=tivit.ies ot any 99.,... emitters that are present when applying a liait that i* baaed upon the risk :froa external qa-.a*exposure. Thia correctly reflects the risk basis that ~the! pCi/CJ criterion tbat appears in various placu in 19;2, YO\\l bave alao aalced a.boat t:he relevance anc.t appropriateness to the Wellt. Chicago llPL sites of tho 15 pei/g criterion which is also iO\\UJd in several places tbrougboat~CFR 192. 'lbis criterion is not ri&lc based. i:t vas deval ~elusively for use** a "finding" tool for relativGly hip concentrations of mill tailing* that: were l'lOt axpectad to be adaixed with appre.- ciabl* quantities of adjacent aoil. It would not serTe its intended fanction if used u a criterion to locate conbJlination ~or reaoval at:. t:b.e West Cbicago vicinity propertie.11, aince 1:bese sites have *ignificuat quantities of low act.ivi'ty*nuarials and significant *ild.ng. vith background u.terials has occ::urred. Tbia issue is addreaaad in greater detail in tbe attacbed -...orand1111 t:o Region 2. As you aay be a.ware, ORU ia in tho process of clevelopi.ncJ standards for tba cleanup of radioactively contllllina1:ad *itea.. It 1s, t:hu:aton, of great benefit for us to work with the Regions on isaues related to c:arrent cloan-up dacisions. Thank . you for this opportunity. Attaclment cc:

Rayaond BrandVein (6601.J')

Larry Jensen, R439ion 5

Frank Cardile UNITED STATES ENVIRONMENTAL PROTECTION AGENc°v0uclN~TlO WASHINGTON, O.C. 20460 October 6, 1997 "97 OCT 17 All :46 OFFIC~ O~ SECFk: Tr-\\f{y RULE 1 "J(lf-:*~:~:; r\\r~D ADJUDICA 1,o,, ~1oof>f AIR ANO RACIATION Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 OOCKET NUMBER . ROPOSED RULE PR :;LO (6')__ f fl Jo/O'1.3) ':-/0

Dear Mr. Cardile:

This letter is in response to the Nuclear Regulatory Commission (NRC) request for additional comment on the Radiological Criteria for License Termination: Uranium Recovery Facilities. EPA has comments on the relationship between radium concentration levels and corresponding dose levels. Specifically, EPA believes that surface wind blown contamination of radium at 5 pCi/g would result in doses consistent with the minimally acceptable dose limit of 15 mrem/yr EDE under a residential exposure scenario for radium*226, radium-228, and thorium-232, and is much more stringent for thorium-230. For land uses other than residential (e.g., commercial/industrial, recreational) the UMTRCA cleanup standards are more stringent for all four radionuclides (see attachment analysis Reassessment of Radium and Thorium Soil Concentrations and Annual Dose Rates, July 22. 1996). EPA will be providing more detailed comments on this issue and related issues in the next week. We are currently coordinating comments internally within the agency. Ifwe can be of any additional assistance, please call me at (202) 233-9280. Sincerely, ~~l-~ John M. Karhnak~~ector Center for Cleanup and Reuse Acknowledged by card fl (!) ~"& Recyclecl/Recyclbl* [)- Prtn&ad wllh SgyJCarga ir-. an JIIIPllf lhal 'O c:amalna Ill la8III 50'!1, rKyded ll)ar c0/c0 ' d 0s96 ££c c0c 80 :Bt l66t-90-1JO

\\.,

CKET NUMBER PR ~' -.OSED RULE ~0~ iF IL s (/:>:Z.. Ffl.. 3o/Oi 3) Jim Edgar Governor I DEPARTME 1:Nu AR SAFETY 1 E SPRI ~~- 62704 21 - D) October 6, 1997 Thomas W. Ortciger Director ~ 0 c...:n~ ~ CC---' r-n 0, **r 0 o-::,~ R ....,~ c: O ~J"" !.>._ -i <.n C") .. (.") -

z::::x=

t,"1 A

Secretary C., ,.,...) c-,-f,,, U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Attention: Rulemakings and Adjudications Staff "T.1 ~~~f; i:.,"

• 1
• ,iL'.

ii ::.~ "'t> N ~ Ul Re: Radiological Criteria for License Termination: Uranium Recovery Facilities. [62 FR 39093-39095] Gentlemen: The Illinois Department of Nuclear Safety (Department) hereby submits its comments on the above-identified Federal Register notice. This notice requests comment on the setting of specific standards that should be used for cleanup of radionuclides at uranium recovery facilities. The primary issue discussed in the notice involves the establishment of cleanup standards, either by setting specific concentration limits for radionuclides currently not included in the regulation, or by codifying a dose objective for those radionuclides. Comments were requested, in particular, on the approach of using a dose objective to establish the standards. 0 The Department has previously commented that rulemaking needs 'to be tooted in technical considerations involving the relationship between radioactivity and dbse to the public. The dose projections should be based on a substantial fraction of the 100 mrem annual public exposure limit. The fraction used by the agency of authority should be one of the allowed variables in the dose projections, as are the other current modeling factors of pathway, population density, land use, etc. While the dose-limit fraction is is not the primary topic of the NRC's current request, it can affect the subject cleanup standards if those standards are based on a "dose-fraction" objective. (OT S 1 t197 @ recyclable Acknowledged by card..................................

.. NUCtt:~f-tf-tt:GULATORY COMMISSION RULEM/11(! 1GS &.l\\DJUDICATIONS STAFF OFf!C[ OF THE SECRETARY Or THE COM,JllSSION Docu:nent S':!istics Postma*:< Cate / o / 7 / '17 Co;Ji::-S Re!:Ei ~- ~ - --=,------ Add! Ca1u C!:.-r ~ *c.;._,d ---~ ---- Sp~c;ai 01.,, iLu.._c1 H~ Ji> n ac.~ Sc.-1.._,.,q ei't. Co..11--of_L l~

U.S. Nuclear Regulatory Commission October 6, 1997 Page2 In the establishment of either concentration limits or dose-objective standards, NRC should not lose sight of the primary consideration which has historically driven the establishment of exposure limits and cleanup criteria, i.e., the potential hazard to human health. Consistency between NRC and EPA is not a reasonable motivation if the proposed standards are not technically-based and defensible. Dose-objective projections have always been of primary import in the evaluation of proposed site clean-ups. All agencies of jurisdiction use dose objectives as a major part of setting site clean-up concentration limits. If a dose objective can be satisfied by cleaning up to concentration limits higher that those specified in regulations, procedure allows for the approval of the higher concentrations. Although EPA typical practice is to specify a concentration limit as the regulatory standard, its acceptance of the concept of higher alternate concentration limits (ACLs) essentially validates dose-objective standards. It is incumbent upon the licensee and agency of jurisdiction to demonstrate that the facility, after cleanup, will not pose a substantial potential hazard to human health. EPA obviously has considered site-specific, dose-based criteria as an acceptable method of controlling risk. For dose projections to be effective in establishing residual concentration and cleanup criteria on a site-by-site basis, the NRC needs to be very clear and comprehensive with the guidance documents it provides licensees and Agreement States regarding acceptable projection methodologies and virtually every factor used in the modeling. If a dose-objective standard is established by regulation, rather than a concentration limit, then acceptable dose projection methodologies should be clearly defined to assure reasonable, fairly consistent results. When defining acceptable dose-objective standards, methodologies, and guidance on dose-objective compliance, the NRC should take care not to inadvertently introduce ambiguous terms, factors or methods. While methodologies for evaluating compliance with dose-objective standards should be somewhat standardized, future refinement of projection methods and factors should not be inadvertently discouraged. Additionally, the Department reiterates its position that, in the establishment of dose-objective criteria, the Agreement States currently have the authority to establish stricter standards than the NRC; no authority needs to be "granted" by the NRC. The Agreement States, therefore, also retain authority to utilize more stringent projection methodology and factors than any NRC-proposed modeling. NRC has proposed the use of the current radium cleanup concentration limit as a "benchmark" for establishing dose-objective standards for other radionuclides. If, as

U.S. Nuclear Regulatory Commission October 6, 1997 Page3 stated in 62 FR 39093, cleanup of radium to NRC concentration standards "would generally result in doses higher than the 0.25 mSv/yr (25 mrem/yr) unrestricted use dose criterion of the final cleanup rule", then it would seem clear that every effected site must be subjected to dose-projection modeling. Even if the same concentration limit is used to clean up different sites, the variability in site characteristics and pathways produce different annual dose potentials. A site cleanup should always be primarily based upon projected dose, not upon specified concentration limits. Rather than setting new limits for radionuclides currently not included in regulations, the establishment of dose-objective standards is more appropriate and effective in the assurance of public health. A specified concentration limit should never be the ultimate test of an adequate cleanup. Every remediation plan, on a case-by-case basis, should include projections of future dose (i.e., hazard,) accounting for all radionuclides of concern. For previous and current cleanup sites, regardless of the concentration limits specified by regulations, dose projections have been, and are being performed. In general, the Department encourages the use of dose-objective standards because they provide to the regulatory community the greatest freedom and flexibility in fulfilling our obligation to protect public health. Thank you for the opportunity to comment on this issue. If you have any questions regarding these comments, please contact me at (217) 785-9947. SCC:DSP Sincerely, J~e,,~

• Steven C. Collins, Chief Division of Radioactive Materials cc:

Richard L. Bangart, Office of State Programs, NRC James Lynch, State Agreements Officer

John S. Hamrick DOCKET NUMBER PR u o PROPOSED RULE 2-. O d: -, C., 2-F Yl 3o/O °13) UMETCO MINERALS CORPORATION 2754 Compass Drive, Suite 280 Grand Junction, Colorado 81506-8741 Manager Health. Safety & Environmental Affairs 970-256-8820 Fax 970-245-7543 October 3, 1997 Secretary ~:oS U.S. Nuclear Regulatory Commission Washington, D. C. 20555-0001 c~o o rn:r -s: 8 g,,o '-\\-,;::"Tl Attention;

Subject:

Gentlemen: oz(/) J, Rulemaking and Adjudications Staff [ 180 -o (.:)~r,=; °' Comments on Radiological Criteria/or License T~"'!!Jtion.~ Uranium Recovery Facilities (Federal Register Voliime(62, Number 139, Monday, July 21, 1997, pages 29093-29095) Umetco Minerals Corporation (Umetco) hereby submits comments on the above referenced rulemaking. Umetco holds three uranium recovery (UR) licenses under the Atomic Energy Act. Two licenses are under Colorado's Agreement State authority (Uravan and Maybell Title II) and one license is issued by the NRC (Umetco-Gas Hills). Umetco staff have reviewed comments submitted by the National Mining Association and Wyoming Mining Association and supports both sets of comments. In addition, Umetco provides the following comments. At present, implementation of 10 CFR 40, Appendix A and 40 CFR 192 criteria for radium cleanup in soil is based on using a site-wide average radium-226 background value to test whether any 100-square meters exceeds the background value by the specified amount. Umetco would like to point out that using a single site-wide background number should be used to test a site-wide area. The mathematical nature of statistics guarantees that use of a site-wide average to test portions of the site will result in falsely identifying material as requiring remediation. If it is desirable from a policy standpoint to use an area average (site-wide) as the test, then the area tested should be on the same basis (site-wide). If it is desirable to test each individual 100-square meter block that comprises a site, then the proper test is not an average but a statistical distribution. The following illustration may help provide an understanding of the above discussion. Suppose that an unaffected area is identified that can be appropriately used to determine background. Assume the unaffected area is large and that many 100-square meter blocks are sampled to determine the average. Further suppose that several of the blocks show ~~IT' 1r 1 1997 Acknowledged by card..................................

U.S NUCLE.~R REGULATORY COMMISSION RULE;. AK:, 'GS & ADJUDICATIONS STAFF c:= 1C'.: OF THE SECRETARY -TriE cm... ~!:SION PJr:m~rk C:* ~ / D 7 /q 7 Cop,e:: ~-=- -:.i __ / ______

natural activities well above the regulatory standard. If the average is then calculated and the unaffected area itself subjected to the test, several of the blocks will be falsely identified as being above the regulatory standard. This will indeed be the case at all UR facilities located within uranium-mineralized areas. The conclusion that can and should be drawn is that if the regulatory standard is applied in unaffected areas and results in false identification of materials to be remediated, then there is a problem with either (and perhaps both) the standard or its application. Thank you for your consideration in this matter. Truly yours, John S. Hamrick

OCT-6-97 MON 1: 15 PM COTTERCORPORATIONN Cotter Corporation,,.~ General Office ~ 12696 Wesl Beyeud Avenue, Suite 350 Lekewood, CO 80228 Phone (303) 980-1292 FAX (3031980-1298 SENT VIA FACSIMILE Secretary U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 FAX NO. 303 980 1296 DOCKETED USNRC '97 OCT -8 P 2 :Q 1 nt="FlC - OF SECRl-r;-\\ Y October 6, 19""-'RULEMAKli\\JGS /,; D ADJUDICAI 10 S STAFF Re: Radiological Criteria for License Termination: Uranium Recovery Facilities Attention Rule Makings and Adjudications Staff:

Dear Commissioners:

P. Cotter Corporation, a New Mexico corporation, maintains offices and mining properties in Lakewood, Canon City, Golden and Canon City, Colorado and has mining properties in Wyoming and Utah as well. As the owner of one of the few remajning operational conventional uranium mms and also other in situ mining prospects, Cotter is substantially impacted by the above-captioned rule for which the Commission seeks radiological criteria comments. Cotter has researched various background information documents and regulatory criteria. In addition, Cotter has reviewed the comments and rationale of the National Mining Association and comments offered by Western Nuclear, Inc., another uranium mining company. In this regard, Cotter suggests that the Commission retain dose criteria which would be equivalent to that exhibited by the Radium-226 pursuant to both 40CFR192 and 10CFR40, Appendix A. Specifically, the 5pCi/g from the 0-15 cm depth increment and 15pCi/g from 15-30 cm depth increment relative to soils cleanup standards should be retained. Lessening of these standards by the Commission would cause undue economic burdens to industry and the government (i.e., D.O.E.) and, as previously noted by the commission, would noc result in significant (if any) risk reduction. In addition to this suggestion, Cotter (a member company) endorses the comments offered by the National Mining Association and those offered by Western Nuclear, Inc. As always, Cotter appreciates the opportunity to comment and is hopeful that the Commission will strongly consider retaining the already existing and extensively applied cleanup standards. RDZ\\dd l>J:>Z\\17.RDZ Rich D. Ziegl Executive Vice President and General Manager OCT 3 t-1111' Acknowledged by card........................... -

Postf"'z, k *' ,* _fa..x_~r.A lo/&/11 Cop,.:.:; i\\,::;:, / Add'I Co),_** * : ~ ,., 5 Special i.Ji..,*.~;*: *. ~*,_/[;.I...J/J..f,q t)/2, I,) i I) }'\\, L.., c... ~ l+L uc::,,.u____,--r_

WESTERN NUCLEAR, INC. UNION PLAZA SUITE 300, 200 UNION BOULEVARD, LAKEWOOD, COLORADO 80228 TELECOPIER (303) 989-8993 TELEPHONE (303) 989-8675 October 2, 1997 DOCKET NUMBER PR 1.0 Ir '-Jo p~'OPUSED RULE ( 6 2 F rt 3 Cf O Cf 3) Secretary U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852 Attn: Rulemakings & Adjudications staff DOCKETED USNRC "97 OCT -8 P 2 :03 OFFICE OF SECFH: i ARY RULEt,At.,/, *JC-, /t~D ADJUDICATlC !*J~~ :..;TAFF Re: COMMENTS REGARDING RADIOLOGICAL CRITERIA FOR LICENSE TERMINATION: URANIUM RECOVERY FACILITIES [62 FR 390931

Dear Secretary:

On July 21, 1997 [62 FR 39093], the Nuclear Regulatory Commission published a request for additional comment regarding the radiological criteria for license termination, specifically concerning uranium recovery facilities. In accordance with that request, please find attached Western Nuclear, Inc. comments. Western Nuclear, Inc. appreciates the opportunity to provide comment. Should you have any questions, please contact us at your earliest convenience. Sincerely, ¥=-~~~- Stephanie J. Baker Manager of Environmental Services SJB/tic nrc\\25mmn97.o02 w/ attachments cc: KCB [w/ attach. ] JRG [w/ attach.] LLM [SMI] [w/o attach.] L. Pruett, Esq. [w/ attach.] H. Shaver, Esq. [w/ attach.] K. Sweeney, Esq. [NMA, w/ attach.] T. Thompson, Esq. [w/ attach.] Acknowledged by card..................................

IJ.S. NUCLEAR RECULATOrW COMMISSION RULaU\\l<*~!C.:., l~ AJJ'.,)IC/.ff1Ui;8 STAFF

Response to NRC Request for Comments Regulatory Criteria for License Tennination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) The decommissioning and license termination for uranium recovery facilities, including conventional uranium mills and parts of in situ leach operations, has been governed by the regulations and criteria promulgated by the Environmental Protection Agency (EPA) under the authority granted to that agency by the Uranium Mill Tailings Radiation Control Act (UMTRCA). These criteria, as set forth in 40 CFR 192 and 10 CFR 40, Appendix A were developed to be protective of public health and are considered to be appropriate. Therefore, the overall regulations which will guide decommissioning of uranium mills and in situ leach facilities should be consistent with the ex_isting standards. The EPA activity concentration standard for Ra-226, as given in 40 CFR 192 and adopted by the NRC in 1 0 CFR 40, Appendix A is 5 pCi/g averaged over the top 15 cm of soil and 15 pCi/g averaged over any 15 cm layer below the surface. These concentration standards are applicable to residual 11 e2 byproduct material from uranium mills, including tailing, ore that has been stored, crushed, or sorted on site, \\ yellowcake or mill solution spills, and all other processing wastes. The uranium and its decay products may be in equilibrium in 11e2 material, as in ore dust, or may have elevated concentrations of one or more of the nuclides in the U-238 decay series as in tailings and mill process spills. The 10 CFR 40, Appendix A concentration standard for Ra-226 assumes the presence of the other uranium decay chain radionuclides. Therefore, for areas impacted by 11 e2 byproduct material in equilibrium such as ore dust, the standard allows 5 pCi/g Ra-226, 10 pCl/g U-nat, and 5 pCi/g Th-230 in the top 15 cm. The standard allows 15 pCi/g Ra-226, 30 pCi/g U-nat, and 15 pCi/g Th-230 averaged over any 15 cm layer below the surface. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 1

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) The philosophy of radiation protection, which has been cod med in 1 O CFR 20, is that doses must be kept as low as reasonably achievable (ALARA) taking into account the state of technology and social and economic factors. Based on past experience with decommissioning of uranium recovery facilities, cleanup to the EPA Ra-226 standard has resulted in residual radionuclide concentration levels that are ALARA and generally within the range of site background. Other factors which must be considered in setting standards for uranium recovery facilities include: Risk: Cleanup is not a risk-free activity. The real risk of moving significant quantities of soil is not negligible in terms of fatalities and lost-time acciqents. The risks of construction are actuarial risks while the risks of exposure to low levels of radiation are hypothetical risks which have not been demonstrated in human populations. Complexrty: The complexity of applying more than one risk-based standard to a single site is not Qalanced by any risk reduction. Consistency: A cleanup standard for uranium recovery facilities that covers all nuclides, and is consistent with the existing EPA standards for 11e2 byproduct material, including all waste from the processing of uranium ore, would be protective of public health and ALARA, considering the unique cha~cteristics of these facilities. The methods employed to clean up residual contamination and verify statistically that the cleanup standards have been met result in residual radionuclide levels in the range of background. In addition.to having no impact on radiation related risks, cleaning up areas to levels below regional background averages would most likely result in a net human health and environmental detriment. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 2

Response to NRC Request for Comments

• Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095)

Therefore, the existing dose criterion implicit in the EPA uranium mill clean up standards, is appropriate for all radionµclides of concern and all areas of uranium recovery facilities. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 3

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 1.0 Introduction The request by the* NRC for.comments regarding regulatory options for Regulatory Criteria for License Termination for Uranium Recovery Facilities (UR) includes several important observations and conclusions: The current standard applicable to uranium mill tailing disposal (10 CFR 40, Appendix A) is not affected by the Decommissioning Rule since the authority for regulating tailing resides with EPA under UMTRCA. The NRC standard is compatible with the EPA standard, 40 CFR 192; Therefore, the issue of concern with regard to regulatory options is limited to uranium and thorium concentration standards. There is no need to address ground water requirements at uranium recovery facilities because 10 CFR 40 conforms to 40 CFR 192 which specifies ground water cleanup standards for uranium recovery facilities. The radionuclide of concern with regard to tailing is Ra-226 (and, by inference, Th-230 due to build-up of Ra-226). The current standard for clean up of Ra-226, 5 pCi/g above background in surface soils and 15 pCi/g for sub-surface soils, results in an average annual dose of approximately 60 mrem per year. (This dose excludes the dose from inhalation of radon decay products and is almost entirely due to direct gamma radiation from the decay products of radon.) Experience has shown that clean-up of Ra-226 from tailing areas has resulted in average residual activity concentrations in the range of site background. The NRC has no current regulatory standards for cleanup of U-238, U-234, and Th-230 at uranium recovery facilities but has relied on previous guidance as a basis for cleanup requirements. Decommissioning of uranium recovery facilities is a unique case which presents, according to the NRC, "technical and regulatory complexities" which "cause practical problems in applying the standards of the final cleanup rule". These problems indude inconsistent cleanup standards for soils being applied in various areas of the same site, (for exampl'e, windblown tailing impacted areas versus mill process areas). October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 4

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) The EPA criteria for disposal and cleanup of uranium mill. tailings include specific standards for Ra-226 activity concentrations in soil of 5 pCi/g above background in the top 15 cm of soil and 15 pCi/g (5/15 pCi/g Ra-226 standard) for sub-surface materials. An inferred standard for Th-230, based on in-growth of Ra-226, has been applied as well. In the absence of a specific regqlatory standard, the clean up criterion for uranium has been based on a 1981 NRC Branch Technical Position relating to on-site burial of waste containing radionuclides in the thorium and uranium decay series (NRC 1981). 11! recognition of their unique characteristics and the existing regulation of portions of uranium recovery. fa~ilities by EPA under UMTRCA, these sites have been excluded from the recently promulgated decommissioning regulations, which require a site cleaned up for release* for unrestricted use to a level such that the annual total effective dose equivalent (TEDE) to any individual would be 25 mrem or less from all pathways of exposure. However, specific decommissioning criteria for uranium recovery facilities are necessary to eliminate confusion and to ensure that the sites are cleaned up to a level which is consistent across the site and protective of public health and the environment. Site-specific overall cleanup standards should be developed using the dose criterion inherent in the existing EPA regulations and modeling to take into account the unique characteristics of each facility. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 5

Response to NRC Request for Comments Regulatory Criteria for License Tennination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 2.0 Current Regulations The current EPA regulations and guidance applicable to uranium mill tailing (40 CFR 192) cover both residual concentrations of Ra~226 in soil and concentrations for all alpha emitting radionuclides, except radon, in ground water. There are no specific clean up standards for U-nat and Th-230 in soils in uranium recovery facilities. The U-nat sta~dards, currently applied on a site by site basis to uranium mill clean up, are based on a 1981 Branch Technical Position (46 FR 52601, -e October 23, 1981) referenced in the Action Plan to Ensure Timely Cleanup of Site Decommissioning Management Plan Sites (57 FR 13389). This document specifies standards for radionuclides buried on site of 10 pCi/g for U-nat in equilibrium with its decay products~ *35 pCi/g for depleted uranium, and 30 pCi/g for enriched uranium. These standards have been applied in conjunction with the EPA 5/15 pCi/g Ra-226 standard by using the "unity rule". That is, the sum of the ratios of the concentration to the applicable standard for Ra-226 and U-nat mu.st be less than or equal to one. Where: [Ra-226]-[Ra-226]bkg [U-nat]-[U-nat]bl(g -10pCi / g 5pCi/g + 20pCi/g

$; 1.0

[Ra-226] = total Ra-226 concentration (pCi/g) [Ra-226]bkg = background Ra-226 concentration (pCi/g) [U-nat] = total U-nat concentration (pCi/g) [U-nat] bkg = background U-nat concentration (pCi/g) The Th-230 concentration standard is derived based on the ingrowth of Ra-226 such that the total Ra-226 would not exceed 5 pCi/g above background at any time within the next 1,000 years. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 6

Response to NRC Request for Comments Regulatory Criteria foi: License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) The 1981 Branch Technical Position states that the uranium standards are based on EPA standards for protection of public health from transuranium elements present in the environment as a result of unplanned contamination. The standards were derived to limit the committed dose to lung to 1 mrad per year (approximately 2.4 mrem per year committed effective dose equivalent) and the dose to bone to 3 mrad per year (approximately j.8 mrem per year committed effective dose equivalent). These standards are inconsistent with the current EPA standards for uranium mill tailings. Risk and dose models which use site-specific parameter values should be e employed to determine reasonable soil concentration standards for radionuclides other than Ra-226. The total allowable dose from the residual radionuclides of concern (Ra-226, U-nat, and Th-230), attributable to uranium recovery operations, should be consistent with the dose from a soil activity concentration equal to the 5/15 pCl/g Ra-226 standard. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 7

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 3.0 ALARA Concept The NRC adheres to the basic philosophy that radiation doses should be kept as low as reasonably achievable (ALARA), taking into account the state of technology and social and economic factors, and that an "acceptable risk" standard should be applied in the form of cleanup criteria, based on cost-benefit and technical tradeoffs. ALARA practices are to be applied on a site-specific basis to require cleanup to levels below those consistent with the clean up criteria as appropriate. The methods employed to remove soils wrth residual Ra-226 concentrations in excess of the 5/15 pCVg Ra-226 standard result in post-reclamation residual radionuclide concentration levels that are ALARA. NRC has recognized that situation by stating that "In actual practice, cleanup of uranium mill tailings results in radium levels lower than the 10 CFR Part 40 standards, and Ra-226 is usually removed to background levels during cleanup of uranium and thorium to the levels in existing NRC guidance documents." (FR Vol. 62, No 39, Section I, p 39094). This statement clearly reflects the NRC position that remediation practices employed to meet the cleanup criterion of 5/15 pCi/g for Ra-226 result in cleanup to ALARA. Decommissioning standards for uranium mills are generally met by excavation of impacted soils. For practical reasons, this results in cleanup to soil concentrations well below -the current 1 o. CFR 40 cleanup standard. In addition, the process required to verify that the cleanup criteria have been met, with an appropriate level of statistical certainty, results in average concentrations significantly below the EPA/NRC standard and generally within the variability of ba~kground. These factors combine to ensure that residual radioactivity will be reduced to levels that are ALARA when cleanup confonns to the requirements of existing EPA/NRC regulations. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 8

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 4.0 Feasibility Issues 4.1 Detection Capabilities 4.1.1 Instrumentation* Low levels of residual radioactivity, in the range of the cleanup standards, are often not detectable above background except by extensive sampling and costly laboratory analyses. In situ methods can detect Ra-226 concentrations at levels in the range of 1 e to 2 pCi/g; however, the inherent variability of background concentrations makes distinguishing the mill-derived Ra-226 eontribution from background Ra-226 concentrations at those concentrations* difficult if not impossible. Since uranium recovery facilities are generally situated in close proximity to areas where uranium is mined, i.e., mineralized areas, background radionuclide concentrations exhibit higher average values and greater variability than concentrations in non-mineralized areas. In situ detection and quantification of U-238 and Th-230 atlevels above background which would result in an annual dose to residents of 25 mrem would not be possible using reasonably available field techniques. Current in situ U-nat and Th-230 activity concentration detenninations for most areas impacted by 11 e2 byproduct material rely on Ra-226 as a surrogate, assuming a site-specific ratio for U-238 to Ra-226 or Th-230 to Ra-226. This is a reasonable approach for windblown tailing or stored ore impacted areas where these ratios tend to be relatively constant, but may not be defensible for mill process areas with elevated radioactivity concentrations due to §pills or releases of mill s9lutions or yellowcake. The Branch Technical Position standards for uranium isotopes, 35 pCi/g for depleted uranium and 30 pCi/g for enriched uranium, are currently used as a basis for U-nat decommissioning requirements. The 30 pCi/g standard for enriched uranium is October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 9

Response to NRC Request for Comments Regulatory Criteria for License Tenninatlon for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) generally applied as it is conservative. It takes into account that the risk from inhalation of U-234 is somewhat higher than the risk from U-238. It is very difficult to detect soil* concentrations above background at these levels except by sampling and laboratory analysis. In situ methods which rely on gamma radiation are not effective due to interference in the measurement by other U-238 and U-235 decay products. 4.1.2 Statistical Issues The variability of the radionuclide concentrations. in the impacted and background areas, and the difference between the mean concentration in the impacted areas and the concentration standard, affect the degree of rigor required in the statistical analyses. As the dose-bas~d concentration standard approaches. background, the number of samples required to demonstrate that the average concentration above background does not exceed the standard increases greatly. This would dramatically increase the cost of demonstrating compliance with the dose criterion. \\ 4.1.3 Grid Size 4t The existing cleanup standards for Ra-226 require averaging the concentration over a 100 square meter area, a 10 meter by 10 meter grid. This is a reasonable averaging area considering the basis on which the hypothetical risk is derived. However, a lower dose criterion may require averaging the concentrations over a smaller grid; thereby increasing the number of samples to be analyzed and the cost of cleanup. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 10

Response to NRC Request for Comments Regulatory Criteria for License Tennination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 4.2 Additional Cleanup Costs and Risks 4.2.1 Increased Volumes of Material to be Moved A 25 mrem per year dose criterion for cleanup of uranium recovery facilities would require excavation and disposal of large volumes of soil which may have been minimally impacted by uranium recovery operations or may, in fact, be unimpacted but have a slightly higher background concentration than the surrounding unimpacted soils. An analysis performed by the Oak Ridge Institute for Science and Education {CRISE) on a Th-232 impacted site to demonstrate adequate cleanup showed that the survey areas were at a lower concentration than the background area chosen for the site* {Abelquist, 1997). The author of this study noted that the background area would not have "passed" the statistical test to demonstrate cleanup to meet the dose criterion had the survey and background areas been reversed. Given the very low radionuclide concentrations required to demonstrate cleanup of uranium recovery facility residues to a level which would result in an annual dose to a resident less than 25 mrem per year, it is likely that a considerable volume of unimpacted soils would be excavated and disposed of as impacted soils. 4.2.2 Increased Cost of Laboratory Analyses The additional costs for meeting and showing compliance with.a 25 mrem per year cleanup standard include the costs of performing all soil concentration analyses using expensive and time-consuming laboratory methods. These laboratory analyses can cost in the range of $500 to $1000 -per soil sample depending on the suite of radionuclides analyzed. Surrogate measures of soil concentrations for Th-230 and U-nat, which depend on a consistent ratio between these radionuclid~ activity concentrations and the activity concentration of Ra-226 'in soil, are adequate to demonstrate compliance with the existing criteria in most cases. However, in order to October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 11

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) meet, and show compliance with, a 25 mrem per year dose criterion, which includes all radionuclides attributable to uranium recovery activities, more extensive and frequent radiochemical analyses for all constituents would most likely be required. This would also significantly increase the number of re-analyses that would be required for samples at or near the concentration standard. The estimated additional cost for laboratory analysis to guide and verify cleanup would be approximately $100,000 per acre. Assume:, 40 grids per acre $1,000 per sample 2.5 composite samples per grid (including a significant resampling requirement) Total *cost per acre = {40 grids/acre){2.5 samples/grid){$1,000/sample) = $100,000 This calculation does not include the costs of excavating and disposal of the additional soils that would require cleanup under more stringent standards than the existing EPA/NRC concentration standards. These costs would be significant, particularly in cases where the disposal capacity on site is limited. The requirements imposed by a 25 mrem per year dose criterion would increase the cost, complexity, and length of time for demoF1strating compliance with the standard to the point where it would, in many cases, force the licensee to contain costs by isolating and covering (reclaiming) impacted areas containing residual radioactive material in accordance with the criteria for reclamation of tailing reclamation as set forth in Appendix A to 10-CFR 40. In addition to the immediate costs of covering large areas of land to the standards required for license termination and transfer to the Department of Energy or other governmental agency, the hidden cost of removing potentially productive lands from future use could be significant should rock rip rap be used to isolate and contain these minimally impacted areas. These lands would then be October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 12

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) unavailable for traditional land uses such as cattle and sheep grazing. The intent of the regulations is* to minimize the area to be covered, thus minimizing the loss of land to productive use and the cost of maintenance of the areas under institutional control. 4.2.3 Construction Risks The risks to workers from heavy construction activities have been well documented. The risk of fatality is approximately 6.9 x 10-a per worker-hour (Zak, 1997); the risk of lost-time injury is 1.6 x 1 o-s per worker-hour (Givens, 1997). These are real, quantifiable risks in contrast to risks of low-level radiation which have not been demonstrated at doses below 10 rem {ICRP 1991 ). Reclamation of a uranium recovery facility to meet current standards is a massive heavy construction operation. The incremental construction effort necessary to remediate the facility to a level such that the annual dose to an individual residing on the reclaimed site would be less than 25 mrem per year (TEDE) is dependent on the characteristics of the site and the surrounding area. However, it is conservative to assume an increase in the level of effort equivalent to 50 workers for 6 months. It is likely that at least one lost-time injury would occur among the members of this 50 person work crew. The risk of fatality for an individual worker employed for six months (1000 hours) in heavy construction is 6.9 x 10*5_ Therefore, the risk of a fatality for a crew of 50 working for six months on the site is 3.5 x 10-3. In contrast to the hypothetical risks from low-level radiation, the risks to construction workers are reat and can be document~d based on past experience. The environmental damage that would result from cleanup to levels below regional backgrounds would be significant since it would most likely require excavation of areas October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 13

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities {Federal Register, Volume 62, No. 139, p 39093-39095) significantly larger than those requiring cleanup to a level consistent with existing standards. Areas that serve as vital ecological habitats would, in many cases, be stripped in order to meet the more stringent standard. Such cleanup would result in I detriment to the area with little or no incremental decrease in risk to human populations. The basis for remediation standards for uranium mill sites is protection of human health and the environment. Therefore, real risks incurred should be balanced against hypothetical risks averted in establishing cleanup criteria.. October 3, 1997 14 p: \\03-349\\sjbltrs\\fr721 rs9. doc

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 5.0 Variability in Radionuclide Concentrations The NRC notes in the response to comments in the decommissioning rule and in the request for comments on a sp_ecific rule for uranium recovery facilities, that doses from radon would be controlled by cleanup of its parent nuclide, radium. The rationale presented by the NRC is that the "variations in radon levels... make it very difficult to distinguish between naturally occurring radon and radon resulting from licensed material" and that it is "impractical to predict prospective doses from exposure to indoor radon due to problems in predicting the design features of future building construction." For these reasons, the Commission doubted the practicality of distinguishing between radon from licensed activities at a dose comparable to 25 mrem per year and that which occurs naturally. This same logic applies te other uranium decay series radionuclides in soils at concentrations consistent with the 25 mrem per year decommissioning standard. Background variability and the presence of non-regulated Naturally Occurring Radioactive Material (NORM) make distinguishing residual radionuclide concentrations, due to licensed activities, from background or NORM at levels in the range of 1 to 5 e pCi/g equally impractical. There are no reliable methods of distinguishing the ore from ore crushing facilities or ore storage pads from NORM or background. The isotopic ratios are similar for the regulated and non-regulated material and for background materials. The current method of distinguishing 11e2 byproduct material from non-regulated material, or background, is based on site history. Therefore, radioactivity in these locations at a uranium recovery facility, at concentrations in the range of those which would result in an annual dose of 25 mrem per year (TEDE) to a resident, may be attributed to 11 e2 byproduct material when, in fact, it is due to NORM or simply background. This could potentially result in the regulatory agency requiring cleanup to leve'ls below background. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 15

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities {Federal Register, Volume 62, No. 139, p 39093-39095) As noted previously, uranium recovery facilities are generally* located in mineralized areas close to uranium mines where the surface and near-surface U-nat, Th-230, and Ra-226 concentrations are elevated. Background radiation exposure rates in these areas tend to be high relative to average U.S. background rates and are extremely variable with surface Ra-226 concentrations, ranging from 1 pCi/g to over 500 pCi/g (Umetco, 1996). In addition, residual Ra-226 concentrations at the surface, due to mining activities, may well exceed the 5/15 pCi/g Ra-226 standard adopted by the EPA for uranium mills. The requirements for remediation of these sites are site-dependent I and are generally much less stringent than the requirements for licensed facilities. For example, the State of Wyoming applies a cut-off concentration of 20 pCi/g for Ra-226 for restoration of abandoned mine lands (Wyoming, 1991 ). Therefore, while a uranium recovery facility may be cleaned up to a surface Ra-226 concentration of 5 pCi/g, a larger surrounding area may be cleaned up to a Ra-226 concentration of 20 pCi/g. On average, the incremental risk reduction from the cleanup of the uranium recovery facility to the 5/15 pCi/g Ra-226 standard would be negligible. Cleanup to an even more stringent standard would result in a net human health and environmental detriment. The risk of a radiation dose to human populations is the same regardless of whether the dose is due to residual activity from licensed activities or from background. Therefore, cleanup of 11e2 byproduct materials at uranium recovery facilities to levels below activity concentrations in the surrounding areas, whether the elevated activities are due to background variability or past mining operations, will result in little or no reduction in risk from residual radioactivity and may, in fact, increase overall risk due to the nature of the excavation and earth moving operations required for clean up. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 16

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facillties (Federal Register, Volume 62, No. 139, p 39093--39095) 6.0 Uncertainty in Cleanup Standards The uncertainty in cleanup standards for uranium mills has been a deterrent to timely and effective reclamation. It is essential that reasonable standards, consistent with the existing 5/15 pCi/g Ra-226 standard, be implemented for uranium recovery facility areas where Ra-226 is not the predominant radionuclide. Decommissioning that is accomplished under these standards must be accepted as final. Protection of public health and the environment can best be attained by remediating the 4t uranium recovery facilities in a timely fashion. In order to proceed with the decommissioning of these facilities, it is essential that sites with approved plans under existing standards be allowed to implement the plans with the certainty that if the site is remediated in compliance with the plan and meets the existing standards, the license will be terminated and the site transferred to the appropriate governmental entity with no lingering liability for the licensee. It is unreasonable to clean up one area of a site, the mill process facility, to a more stringent standard than is required to be met for a much larger area potentially impacted by windblown tailing. Therefore, a dose criterion consistent with the existing Ra-226 standards would be reasonable, attainable, and protective of human health and the environment. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 17

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 7.0 Proposed Alternative The alternative initially proposed by the NRC, i.e. that the cleanup criterion for uranium recovery facilities be consistent with the existing EPA regulations applicable to tailing, is reasonable. This would require that the mill sites be cleaned up such that the annual total effective dose from all residual radionuclides (excluding inhalation of Rn-222 decay products) would not exceed the dose attributable to the 5/15 pCi/g Ra-226 standard, assuming all Ra-226 decay products are in equilibrium. A criterion such as this would allow flexibility in cleanup and ensure that the mix of residual radionuclides on the mill site itself would present no greater risk than the residual tailing outside of the area under permanent institutional control. Implementing a lower dose criterion for other areas on the mill site would not reduce the hypothetical risk to future users of the land but would increase the real risk to workers. The facility being reclaimed should have the option of establishing site-specific soil concentration standards for uranium and Th-230, which would result in no greater dose than would result from residual radionuclide concentrations at the EPA/NRC 5/15 pCi/g Ra-226 standard. The particular characteristics of the site, background levels, and reasonable potential land use should be taken into account in deriving these values using accepted dose modeling codes such as RESRAD. The parameter values selected for input to the dose modeling code should be reasonable, i.e., not excessively conservative, since the cleanup activities required to reduce radionuclide concentrations are not risk-free. The types of cleanup activities for the mill sites, i.e. excavation and disposal on site to areas under permanent instiMional controls (areas deeded to the Department of Energy or appropriate state agency), would result in the same reduction in residual concentrations as have been observed with tailings cleanup. That is, the sites would be cleaned up to within the range of background concentrations just by the nature of the October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 18 (

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facillties (Federal Register, Volume 62, No. 139, p 39093-39095) cleanup methods and the requirements for statistical verification of residual concentrations. Therefore, the potential doses to individuals residing on the site after decommissioning would be ALARA. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 19

Response to NRG Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 8.0 Summary In summary, the cleanup criteria for uranium recovery facilities have already been effectively established by,the EPA under UMTRCA. There is no logical reason for , setting standards based on a different dose criterion for areas of uranium recovery facilities and radionuclides that are not currently covered under existing EPA/NRC uranium mill regulations. Protection of the general public to the levels inherent in the Decommissioning Rule, applicable to other licensed facilities, is a~omplished through the ALARA process, not by setting inappropriate and unreasonable standards. Cleanup of mill tailings to existing standards and guidance has resulted in residual radionuclide levels in the range of background. Unnecessarily moving significant quantities of soil can result in fatalities and lost-time accidents among workers. The risks of construction are actuarial risks while the risks of exposure to low levels of radiation are hypothetical risks which have not been demonstrated in human populations. Uranium recovery facilities are generally located in mineralized areas, close to uranium mines, where background radionuclide concentrations are elevated and highly variable. In addition mill sites are impacted by NORM from mining activities which are subject to much less stringent cleanup standards. The State of Wyoming has established a Ra-226 concentration of 20 pCi/g as the cut-off level for cleanup o( abandoned mine lands (Wyoming, 1991). Cleanup of small "islands" to radionuclide concentrations below the larger area background concentrations provides no significant risk reduction. Over time, despite the cleanup efforts, the radionuclide concentrations over the larger area, including the reclaimed "island", will reach equilibrium due to erosion and deposition of the higher concentration background soils. Application of more than one risk-based standard to a single site adds to the complexity of remediation and is not balanced by any risk reduction. A cleanup standard for uranium recovery facilities that includes all applicable nuclides, and is consistent with the existing EPA standards for uranium mill tailings, would be protective of public health and ALARA, considering the unique characteristics of these facilities. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 20

Response to NRG Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilitles (Federal Register, Volume 62, No. 139, p 39093-39095) Under a 25 mrem per year aose criterion, areas to be cleaned up would be expanded both horizontally and vertically and the requirements for statistically based analyses would be significantly increased. The costs and real human health risk and environmental detriment outweigh any benefit to be gained by imposing a 25 mrem per year dose criterion on uranium recovery facilities. The methods employed to clean up residual contamination, and verify, statistically, that the cleanup standards have been met, result in residual radionuclide levels in the range of background. In addition to having no impact on radiation related risks, cleaning up areas to levels below regional background averages would most likely result in a net human health and environmental detriment. , Therefore, the existing dose criterion implicit in the EPA uranium mill clean up standards, is appropriate for all radionuclides of concern and all areas of uranium recovery facilities. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 21

Response to NRC Request for Comments Regulatory Criteria for License Termination for Uranium Recovery Facilities (Federal Register, Volume 62, No. 139, p 39093-39095) 9.0 References Abelquist,.E.W., Oak Ridge Institute for Science and Education. (ORISE). 1997Results of Preliminary Field Test at a Thorium-Contaminated Site Using MARSSIM Survey Design. Presentation at the Health Physics Society 42no Annual Meeting and Exhibition, San Antonio, Texas. July 1, 1997. Givens. N. Construction Industry Institute, Austin, Texas. 1997. Personal Communication, August 15, 1997. International Commission on Radiological Protection. 1991. Risks Associated with Ionising Radiations. Annals of the ICRP, Volume 22, No. 1. Pergamon Press. Umetco. 1996. Background Land Conditions at the Gas Hills Uranium Project. Materials License No. SUA-648. Preliminary Draft. Umetco Minerals Corporation. Grand Junction, Colorado. April 15, 1996. Wyoming Department of Environmental Quality. 1991. Day Loma Master Plan. April 23,1991. Zak, M., U.S. Bureau of Laor Statistics. 1997. Personal Communication, August 15, 1997. October 3, 1997 p:\\03-349\\sjbltrs\\fr721 rs9.doc 22

'I' f "97 OCT -6 P 4 :41 0 ICE: OF SECP.~ 1-ARY ~----------------~-- ~ ~ ~ -F NATIONAL MINING ASSOC COMMENTS ON THE NUCLEAR REGULATORY COMMISSION'S REQUEST FOR ADDITIONAL COMMENTS ON RADIOLOGICAL CRITERIA FOR LICENSE TERMINATION: URANIUM RECOVERY FACILITIES 500682-01 / DOCSDCl (62 Fed. Reg. 39,093) October 6, 1997 Prepared by: Shaw, Pittman, Potts & Trowbridge 2300 N Street, N.W. Washington, DC 20037 Acknowledged by card 'lftr1r1 '"fl!J7

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r J The National Mining Association (NMA) is a trade association whose members include producers of most of America's coal, metals, industrial and agricultural minerals; manufacturers of mining and mineral processing machinery and supplies; transporters; financial and engineer-ing firms; and other businesses related to mining. NMA member companies potentially affected by this rulemaking include uranium recovery facility licensees with in-situ leach (ISL) and con-ventional milling facilities. I. Re2ulatory History On August 22, 1994 (59 Fed. Reg. 43200), the Nuclear Regulatory Commission (NRC) published a proposed rule for comment to amend 10 C.F.R. Part 20 of its regulations to include radiological criteria for license termination. The public *comment period closed on January 20, 1995 and NMA filed comments on behalf of its uranium recovery licensee members. On July 21, 1997, NRC published a final rule for radiological criteria for the decommissioning of lands and structures for license termination. (62 Fed. Reg. 39058). The August, 1994 proposal stated that with respect to uranium mills, the proposed criteria would apply to the mill facility but would not apply to disposal of uranium mill tailings or to soil cleanup at such facilities, referenc-ing the 10 C.F.R. Part 40, Appendix A, specific criteria for decommissioning uranium mill tail-ings and for soil cleanup at such sites. The proposal did not address the applicability of the proposed rule to ISL facilities. NMA agreed with NRC that the proposed rule would not apply to soil cleanup or disposal of uranium mill tailings given the applicability of the "specific" Appendix A standards governing

those cleanup activities versus the "generic" proposed site cleanup rule requirements for other li-censed facilities subject to NRC jurisdiction under the Atomic Energy Act (AEA). NMA sug-gested, however, that the statement in the draft generic environmental impact statement (DGEIS) indicating that the proposed cleanup standard would be limited to the "mill buildings and imme-diate land surrounding the mill buildings" was not entirely accurate. For one thing, the rule would not be applicable to any portions of mill buildings that are not decontaminated for sale or use at other facilities which can be disposed of in the mill tailings impoundment as so-called l l.e(2) byproduct material.U Additionally, any property at a milling facility necessary for by-product disposal (whether involving soil or groundwater contamination) would be excluded from the proposed unrestricted use decommissioning criteria because by law the property is to be transferred to the Department of Energy (DOE) or a State under the Uranium Mill Tailings Ra-diation Control Act of 1978 (UMTRCA) and licensed in perpetuity by NRC. NMA further noted that the criteria in Appendix A comprehensively address license ter-mination requirements at conventional uranium milling facilities (and, where relevant, ISL facili-ties) including financial surety, long-term stability, site surveillance, groundwater contamination from mill tailings, and, "on a site specific basis," groundwater contamination from source terms other than mill tailings, radium in soil and radon emanation. Thus, NMA suggested that the lands and structures to be excluded from the proposed site cleanup rule should be expanded be-yond just mill tailings facilities to include all uranium recovery (UR) facilities (i.e., ISL as well as conventional mill facilities). In a November 5, 1995 letter to NRC Chairman Shirley Ann .u "... [T]he tailings or wastes produced by the extraction or concentration or uranium or thorium from any ore processed primarily for its source material content." 42 U.S.C. § 2014e.(2). 2

Jackson (Attachment A), NMA specifically suggested broadening the exclusion to include in-situ leach facilities. Considering that ISL facilities currently, and likely into the indefinite future, represent the "backbone" of domestic uranium production, NMA suggested that it would not be wise to impose significant regulatory burdens that could threaten the viability of that production method. For example, failure to include soil cleanup at ISL facilities within the scope of an ex-clusion from the rule could almost instantaneously create major, costly retroactive waste cleanup issues with respect to soil irrigated with process fluids. These issues could foreclose irrigation with process fluids and could have potentially drastic effects on the economic viability of future ISL mining projects. NMA cited documents suggesting that as little as 0.1 pCi/g radium-226 with daughters2L and as little as 0.6 pCi/g of uranium above background11 (which could result from irrigation with well field fluids) could result in exposures of 15 mrem/y. NMA therefore recommended that the language in proposed 10 C.F.R. 20.140(a) (59 Fed. Reg. 43228) be broad-ened to apply to uranium recovery faci/itiesY* In the July, 1997 Federal Register notice containing the final site cleanup rule,ii the Com-mission, citing "complexities associated with decommissioning of these unique facilities which could cause practical problems in applying the standards of this rulemaking to UR facilities," de-cided to exclude UR facilities from the scope of the final rule. (62 Fed. Reg. at 39073). Further, 'Ji. Attachment 8-"EPA Exhibit C Background Levels, Field and Laboratory Detection Limits, and Concentrations Equivalent to a Risk Level of I x 10~ for Selected Radionuclides in Soil." lL Attachment C-"Comments on the Nuclear Regulatory Commission's Proposed Rule on Radiological Criteria for Decommissioning-SENES Consultants, Limited (January, I 995)." +/-'. "For uranium recovery facilit1es, the criteria apply to decommissioning of the facility, but not to the disposal of uranium mill tailings or soil cleanup(~ Appendix A of 10 C.F.R. Part 40)." ~ The final site cleanup rule was changed from the proposed 15 mrem/y dose limit for unrestricted use to 25 mrem/y. 3

the Commission stated that to allow for "full consideration by the Commission and affected par-ties of the issues associated with decommissioning UR facilities and of a series of regulatory op-tions discussed, the Commission published a separate notice (62 Fed. Reg. 39093) as part of the final rule to specifically request additional comment on regulatory options for decommissioning criteria for UR facilities." In the final rule, the Commission noted that the standards as set forth in 40 C.F.R. Part 192 and 10 C.F.R. Part 40, Appendix A, apply to remediation of inactive tailings sites, including vicinity properties, and active uranium and thorium mills. The Commission noted that at ISL fa-cilities decommissioning activities are similar to those at uranium mills and consist mainly of cleanup of 11.e(2) byproduct material. The Commission further noted that applicable cleanup standards already exist for soil cleanup of radium in soils Oand) and that cleanup of radium to the prescribed concentrations6" above background levels would generally result in doses higher ( 60 mremly)1L than the unrestricted dose criterion (25 mrem/y) of the final cleanup rule. However, the Commission also noted that, in actual practice, mill tailings (i.e., radium in soil concentrations resulting from byproduct materiarf-are cleaned up to levels generally lower than ~ Criterion 6(6) -- The design requirements in this criterion for longevity and control of radon releases apply to any portion of a licensed and/or disposal site unless such portion contains a concentration of radium in land, aver-aged over areas of 100 square meters, which, as a result of byproduct material, does not exceed the background level by more than: (i) 5 picocuries per gram (pCi/g) ofradium-226, or in the case of thorium byproduct mate-rial, radium-228, averaged over the first 15 centimeters (cm) below the surface, and (ii) 15 pCi/g ofradium-226, or in the case of thorium byproduct material, radium-228, averaged over 15-cm thick layers more than 15 cm be-low the surface. 11 NRC referenced a 60 mrem/y dose based on an EPA estimate of the dose from radium in soils in the 5/15 pCi/g range without a discussion ofEPA's exposure assumptions. Presumably, a site-specific dose objective based on a benchmark radium in soil dose would depend on the contaminant profile, soil conditions, exposure pathway assumptions and models utilized. ~ Byproduct material may consist of a variety of materials and mixtures depending on site specific conditions Footnote continued on next page 4

the 5/15 pCi/g limits and that radium is usually removed to background levels during cleanup of uranium and thorium pursuant to existing NRC guidance documents.2l However, in some areas where there may have been yellowcake or yellowcake solution spills, yellowcake storage, or where ra:ffinate was sprayed on to soil at a milling facility or where spray irrigation was used as a*- means of disposal at ISL facilities, uranium or thorium could be the radionuclide of concern. In such areas, application of the final cleanup standard criteria to those portions of a UR site con-taminated with uranium or thorium would be subject to more stringent cleanup requirements than large ( 50-1,000 acres) windblown tailings areas where radium is the primary nuclide of concern. (62 Fed. Reg. 39073)..1.Ql In its request for additional comments (62 Fed. Reg. 39093), the Commission reiterated much of the information discussed above. For example, the Commission noted that because Ap-pendix A does not codify cleanup criteria for soil contamination from radionuclides other than radium, it cannot be used as a standard for uranium and thorium cleanup. The 1981 Branch Technical Position is currently used to develop cleanup levels for these and other radionuclides. Appendix A regulations specify groundwater cleanup standards applicable to tailings impound-ments and specify treatment for groundwater cleanup at other UR facilities and for sources other than from tailings on a site-specific basis. Footnote continued from previous page including differing conditions on different areas of the same site. For example, uranium mill tailings may con-tain less uranium with the radium than ore dust from stockpiles located at the mill although both are considered byproduct material. Additionally, yellow cake spills, pregnant uranium solution spills or irrigation effluent could all have differing radium/uranium/thorium relationships.

21.

1981 Branch Technical Position (BTP) 46 Fed Reg. 52,601, October 23, 1981. ill'. At sites where process fluids have been sprayed on to land, the areas involved can be as great or greater than 50 acres. 5

As noted above, NRC stated that cleanup of radium concentrations to the existing regula-tory limits generally would result in doses greater than the 25 mrem/yr prescribed in the final cleanup rule. NRC cites EPA's statement in developing 5/15 pCi/g radium limits in 40 C.F.R Part 192 indicating that, at these levels, the dose from radium, excluding radon, would be ap-proximately 60 mrem/yr (0.6 mSv/yr).lli NRC again suggests that in practice the exposures are lower because it is difficult to scrape up only six inches of potentially contaminated soil cost ef-fectively from any large area with a piece of equipment large enough to deal with such an area. The Commission discusses two possible approaches to address the potential disparity be-tween the dose from radium under Appendix A and 40 C.F.R Part 192 (i.e., 60 mrem/y) and that from uranium/thorium under the final rule (i.e., 25 mrem/y) with respect to site cleanup at UR fa-cilities. The first approach would change the cleanup levels for radium in Appendix A. The sec-ond, which had been developed in response to comments received on the proposed rule, would codify a dose objective for radionuclides other than radium in soil and buildings at UR sites that is consistent with the dose from the 5/15 pCi/g radium cleanup standard already in place. Under this latter approach, facilities would use the potential dose from radium in Appendix A as a benchmark for the cleanup of radionuclides other than radium (i.e., uranium and thorium). As the Commission noted, "use of this approach would thus allow for consistent criteria to be ap-plied across site areas." (62 Fed. Reg. 39093). ill As noted in footnote 7, the actual dose would be determined on a site-specific basis. 6

II. NMA Comments NMA supports the approach developed in response to comments to the proposed site cleanup rule which would be based on codifying the dose objective for radionuclides other than radium in soil from byproduct material by using the potential dose from radium above back-ground at the existing 5/15 pCi/g concentration levels as a benchmark for the cleanup of other ra-dionuclides at all UR facilities. The alternative that would require modification of the 5/15 pCi/g standard is impractical and unacceptable in view of the obvious and needless legal problems cre-ated given EPA's authority under the AEA, as amended (including UMTRCA), to set "generally applicable" environmental standards with which NRC must conform its regulations. 42 U.S.C. § 2114(a)(2). Under the AEA, NRC was required to conform its requirements for regulation of by-product material (including discreet surface wastes resulting from uranium solution extraction processes at Title II uranium mill tailings sites) to EPA's 40 C.F.R. Part 192 standards. NRC did so, and as a result, Criterion 6(6) incorporates EPA's 5/15 pCi/g radium in soil standard. The first alternative also is unacceptable as it would change the standard in 40 C.F.R. §§ 192.12(a)( 1 )&(2) which has been used by DOE for radium in soil cleanup at Title I sites and at vicinity properties. The same 5/15 pCi/g standard in 40 C.F.R. §§ 192.32(b)(2)(i)&(ii) (and in Appendix A, Criterion 6(6)) has been used for radium in soil cleanup of non-tailings areas at two Title II sites that have terminated their licenses. Additionally, this alternative would cause enor-mous unnecessary expense and misuse of resources based on ongoing or proposed cleanup at other Title II sites where license termination has not taken place, but where cleanup or portions thereof has either been completed or is in process based on the 5/15 pCi/g limits. Finally, it 7

should be noted that the existing 5/15 pCi/g standard is essentially an unrestricted use standard. Therefore, although portions of the area around uranium mill tailings piles or impoundments theoretically would be released for unrestricted use, as a practical matter, due to the necessity of obtaining alternate concentration limits (ACLs), substantial areas at most Title II mill sites will not be available for unrestricted use. Any land which is necessary for disposal of byproduct ma-terial, including land between the point of compliance (POC) at the edge of a tailings pile and the point of exposure (POE) that is required to attenuate and/or treat groundwater contamination from tailings or other sources at a milling facility, will be transferred to DOE or the State pursu-ant to the requirements of UMTRCA. Thus, in addition to the tailings themselves, substantial portions of mill tailings sites, including areas where the mill building may have stood, likely will be transferred for perpetual licensing to DOE or the State. So changing the existing 5/15 pCi/g radium standard would generate no benefits (i.e., risk reduction) but would result in huge cost in-creases and regulatory disruption. With respect to ISL facilities, as noted above, NMA advised the Commission that appli-cation of soil cleanup criteria to meet the proposed 15 mrem/yr standard could result in signifi-cant areas retroactively becoming disposal areas requiring substantial and costly cleanups and could inhibit the efficiency of ISL mining were NRC to effectively prohibit the use of irrigation with either "bleed" or restoration fluids. Although the 25 mrem/yr limit in the final rule is not as restrictive as the proposed 15 mrem/yr limit, it is still more stringent than a dose objective for uranium or thorium cleanup that is based on the benchmark radium dose under the 5/15 pCi/g standard. At some mill facilities, the 25 mrem/yr limit may apply only to small areas where there have been yellow cake spills, etc. However, at other mills, and at ISL facilities, it could apply to 8

large areas (i.e., more than 50 acres). Although any areas at ISL facilities cleaned up to meet the 5/15 pCi/g radium standard and a dose objective for uranium and thorium based on the bench-mark radium dose likely will not be transferred to DOE or the State, neither are the vicinity prop-erties associated with Title I sites that are cleaned up to meet the 5/15 pCi/g limits. Moreover, in situations where it is extremely difficult and/or expensive to meet the 5/15 pCi/g standard at Title I sites and vicinity properties, supplemental standards are available that allow DOE to exceed the 5/15 pCi/g limits ( e.g., unreasonable occupational risks, health and environmental harm that is grossly disproportionate to benefits anticipated, costs unreasonably high in relation to benefits and no clear present or future hazard is posed) on properties that are not licensed in perpetuity. (40 C.F.R. § 192.21). In the two rulemaking proceedings wherein the 5/15 pCi/g standard was developed and reaffim1ed (i.e., first in inactive tailings sites (Title I) standards and second in the active tailings sites (Title II) standards), EPA found that concentrations "a few times higher" would cause only slight increases in risks and since concentrations usually decline with depth, a standard of 10 or 20 pCi/g in the top six inches "would be protective" (Inactive DEIS at p. 8-24) as the maximum risk circumstances would be unlikely to occur (1 Inactive FEIS at p. 134). The 5/15 pCi/g stan-dard would achieve "essentially" the same protection as the initial proposed 5/5 pCi/g standard so the standard could be relaxed for ease of implementation without "any sacrifice of health protec-tion." (2 Inactive FEIS at D-51-55). The largest risk from radium in soil concentrations (100-1,000 times greater) is from radon (1 Active FEIS at p.6-11 ), which is not addressed by NRC's final site cleanup rule. (62 Fed. Reg. 39082-83). Thus, the 5/15 pCi/g standard provides 9

a sound and adequately protective benchmark for doses from uranium and thorium at UR facilities. These conclusions are buttressed by a recent EPA "Transmittal of Superfund Radiation Guidance," dated August 26, 1997, from Jeffrey Phillips of the Office of Solid Waste and Emer-gency Response (OSWER), to regional superfund directors. (OSWER Guidance). In the OSWER Guidance, EPA suggests that the 5/15 pCi/g radium standard was developed for specific conditions found at uranium mill sites ("for example, all mill sites are required by law to remain in federal control" and "correlating these concentrations to dose requires a site-specific determi-nation considering both the distribution and nature of contaminants and the selected land use"). Therefore, the standard is less relevant for determining "if 15 rnrem/,yr EDE" is consistent with the 40 C.F.R. Part 192 standard. However, EPA states: "analyses indicates that the cleanup of UMTRCA sites is consistent with the minimally acceptable dose limit of 15 mrem/yr EDE under a residential exposure scenario for radium-226, radium-228, and thorium-232, and is much more stringent for thorium-230." Therefore, the potential dose from the 5/15 pCi/g radium standard as a dose objective for other radionuclides would not only satisfy the NRC's final site cleanup dose limit of 25 mrem/yr ( excluding radon) but would also satisfy EPA's preferred 15 rnrem/yr stan-dard. The OSWER guidance does not explain exactly how the 5/15 pCi/g standard, which at time of promulgation resulted in a 60 mrem/y dose, is equivalent to 15 mrem/yr EDE, however, whether or not there is exact equivalence is not important since it is obviously satisfactory in light ofEPA's bases for the 5/15 pCi/g standard noted above and its extensive use at UR facilities. 10

The point made in the OSWER guidance that correlating dose from the 5/15 pCi/g stan-dard requires "site specific" consideration including "the distribution and nature of the contami-nants and the selected land use." As noted above in footnote 8, radium versus uranium/thorium concentrations in byproduct material in a particular area of a site may vary depending on whether they are the result of windblown tailings, windblown ore dust from ore stockpiles at a mill site, yellowcake or yellowcake solution spills or process effluent that has been sprayed on soil. Another factor that is highly site specific (and perhaps even area to area specific at a given site) is the determination of background. Background fluctuations in mineralized areas where uranium mines (including ISL mines) and mills are normally located can vary (even over different areas of the same site) by orders of magnitude. (Attachment D). Since the regulatory limit (i.e., dose projected from the 5/15 pCi/g radium standard) and any dose objective for ura-nium and thorium based on that benchmark would be an above background limit, site specific flexibility must be preserved. UMTRCA specifically contemplates site specific flexibility to address management of byproduct material through the provisions of Section 84( c) which grants licensees the right to propose alternatives to NRC or EPA requirements that "take into account local or regional condi-tions including geology, topography, hydrology and meteorology." 42 U.S.C. § 2114(c). The availability of site-specific alternatives for regulation of mill tailings under Section 84 of the AEA is consistent with the position that NRC has articulated previously, that site-specific flexi-bility is a necessary feature of mill tailings regulation. For example, in the generic environ-mental impact statement (GEIS) for uranium milling, NRC acknowledges that "mill tailings 11

management is highly site-specific" and "the precise details of a program [for mill tailings man-agement] can be worked out only when unique conditions of a site are known..LU It is also consis-tent with the Commission's regulations governing the disposition of mill tailings, which provide that "[i]n many cases, flexibility is provided in the criteria [ established in the regulations] to al-low achieving an optimum tailings disposal program on a site-specific basis." (10 C.F.R. Part 40, Appendix A). Thus, the existing statutory and regulatory program for UR facilities provides the proper framework for site cleanup at such facilities. If there is one undeniable benefit to this program, it is the flexibility that it provides to address site-specific circumstances in order to sat-isfy very comprehensive and conservative regulatory requirements. DOE at Title I sites, and Title II licensees, have found that moving towards site closure and license termination require such flexibility if such termination is ever to happen. III. Conclusion Since the existing regulatory program provides the comprehensive, yet flexible, regula-tory package for UR facilities to address cleanup of uranium and thorium based on the dose ob-jective of the benchmark radium dose determined on a site-specific basis, as NRC previously determined in response to comments on the proposed site cleanup rule, it is the most appropriate approach to address these issues. Accordingly, NMA supports this alternative and urges the Commission to adopt it as explained in the request for additional comments (62 Fed. Reg. 39094, Column 2), and as implemented on a site-specific basis. ill NRC, "Final Generic Environmental Impact Statement on Uranium Milling," NUREG-0706 (1980), Vol. II, p. A-8 I. 12

National Mining Association R1ch rd L L,11wton

• \\*'
  • 'l I,,1,, I."'"

By Hand Dcliycy The Honorable: Shirley A. Jackson Chairmw U.S. Nuclear Regulatory CnmroiSBion Washington, DC 20555 Re: Proposed Decommissioning Rule

Dear Chairman Jac.tson:

November 3, 1995 1biJ letter addresses two seriowi potential problems with the proposed rule establishing radiological criteria for decommissioning {the D&D rule) (59 Fed. Reg. 43200, Au~ 22, 1994) that could foreclose the rontin*ted viability of llillDiwn production at in-situ leach (ISL) facilities in the United States. As you know, ISL facilities currently represent ~ backbone of this cwntry' s uranium production am likely will do so into the imlefinitc future barring major increases in the prices of "yellowcake." The National Mining Association (NMA) raised these concerns with Nuclear Regulatory C.ommission (NRC) staff on October 2S, 19'J5, in the context of a discussion on the Staff 'Ta:bnical Position (STP) on Effluent Disposal at Licensed Uranium Recovery Facilities (April 1995). Given the anticipated timeframe for finalizing the proposed D&D role, we thought it prudent to bring this to your attention immediately. The STP on effluent disposal states that uranium recovery facilities Adlsposing effluent by on-site land applications are further required to coq,ly with NRC's rcgnlatory provisions for decommissioning... " including NRC's proposed radiological criteria for decommis:sioning (10 C.F.R. Part 20.1400 ~~.)when the D&D rule becomes final. (See STP pp. 3 and 7.) As published in the Fedentl Register, the proposed D&D rule provides that "for uranium mills the criteria apply to decommissioning of the facility but not to the disposal of uranium mill taQlnp or to soil demJnp. (See Appendix A of 10 C.F.R. Part 40). * (Propo5l"tl xction 20.1401(a), p. 43228.) This refen:nced excllWorwy 1aDguage must be modified to include explicitly *soil cleanup" at ISL facilities within the scope of section 20.1401 because, as drafted, it is possible to conclude that surface contamination from land application (irrigation) of fluids at ISL facilities would be subject to che proposed lS millin:m/year (mrem/yr) standard above background for eq"JOSUre to residual radioactivity at I

~ioncd sites. Such an outcome is not *~ or COosistent with NRC practice and essentially could shut down ISL production of unruurn in the United Statca. !SL producers irrigate to~ execs~ water~ PfOCessing operations that results from withdrawing more water than lli ~ iiltO the mrnmg zone to PI'OtCct against ne~ons*_ of ?1jected fluids from the munng _mnc and to assure the Ollgoine efficiem:y of the mim111 Clrcwt. Althcrugh. 0~ ~*the~ purpose of the process is to lffllOVC m:aniura from the water in the circUit and the ~ IS also treated to reduce radium concentrations prior to irrigation, it takes only a incrancntal mimu.1cule amount of uranium or radium surface radioactivity to raise levels to implicate the 15 mrem standard. For example NRC's background documents in support of the D&D rule suggest that ~ of U-. 238 in soil between 0.3 and 0.6 pico curie per gram (pCi/g) above background (depending on daughter products) will implicate the 15 m limit. (See attached NMA comments on the D&D rule.) An EnviroomPJrtal Protection Agcrr.y (FJ>A) ~ prcscntcd at a May 18-1,, 1994. National Advismy Council for ~:!"I Policy and Technology (NACEPT) meeting suggcstB that as little as 0.1 pCi/g of radium with daughters above background would implicate the 15 mrem limit. (See attachment.) These tiny increments to natural levels are e:xtICuk;ly difficult to measure accurately in areas where uranium is mined and may be caused by NRC or Agreement State pennittoo ISL reJrascs-Irrigation with these effluents is critical to efficient. competitive uranium production at ISL facilities. Without such capabilities. pmduction at many facUities would ~ve to be severely constrained or even rerrnioated entirely due to non-compctitivcncss in the market place. Thus, the language in the propo&ed rule should be modified to mat.e it explicit that the 15 mrcm limit will not apply to "soil cicawp* at ISL facilities as follows:*

• For uranium recovery facilities, the criteria apply to decommissioning of the facility. but not to disposal of uranium mill tailings or soil cleanup (see Appendix A of 10 C.F.R. Part 40~. ~

This change to the proposed rule would be consistent with NRC's application (and the underlying intent) of 10 C.F.R. Part 40, Appendix A criteria. which have been applied consistently to ISL facilities from the inception of Appendix A. By making ~tion 20. 1401 of the proposed D&D rule apply to unnlum reco~ery fariUtles (rather than jllSt to uranimn mills). the Commission will avoid any potential for confusion and inconsistent implementation of the D&D rule at ISL facilities in the fu~. NMA respectfully requests that the above modification be made in the final D&D rule. A related but separate concern with the proposed D&D rule lies in the proposal's application of the 15 mrem standard to "residual~-* The proposed rule defines "residual.-adioacti'fity" as "radioactivity in structures, materials, soils, groundwater, and other media at a sire resulting from acthities under the licensee's control. This iD;ludes radioactivity from all licensed and uollcensed som~ used by the licemee.*. * (proposed section 20.1003). There may be activities under a licensee's cootrol involving radioactivity (i.e., mining) that are neither subject to NRC's jurisdiction nor occur on portions of a site 2

subject to NRC jurisdiction or both. At ISL f'acillties, the portions of a site utilizing irrigation for disposal of weDfield ratantloa effluent and p<>BSlDly the sludges in some radium treatment pondl are nQ! under NRC'1 jurisdiction, ~gh they are clearly under the control of the licemee. NRC would. therefore. have no~ for llSICrting the applicability ot its D&D criteria to these areas of the site. Additiooally. any authorized effluent releases off-site that are within generic NRC regulatory and/or specific licenac releuc limits at the time of release also cannot be considered to result in cooccutrations of radioactive materials that are subject to NRC"s jurisdiction. Again. it is inappropriate for NRC to attempt to extend its regulatory reach through the proposed. D&D rule or any other rule imo areas over which it bas no jurisdiction. NMA requests that the Commission address and resolve this problem in the fiDa.l ru.le. 1 If you have any question or if we can be of farther usistance on this maticr, please cuntact Katie Sweeney, NMA Aasociatc General Coumel, at 202/463~2627. Sincerely, ~~ Richard L Lawson 3

AU--8TAW L.60Af.. l!IXI-Z22-01510 IDA11 Rl!OYCLED

Exhibit C Background Levels, Field and Laboratory Detection Limits, and Concentrations Equivalent to a Risk Level of 1 x 1~ for Selected Radionuclides in Soil Radionuclide Concentration lpCl/gl Calculated at 10... Risk Level Using RESRAD 5.0 Rangeof Gamma Field Survey Generally Achievable MDC Typical Background Becllground Levels Detection s.n.Jtlvfty Via Commm:lal Commerdel/ Radlonudlde Level lpCl/gl lpCl/gl lpCl/gl Laboratory fpCl/gl Rnldentlel lnckntrtal mes+ D 0.7 0.1 - 3.5

3. 1 - 19a.*

0.01 3 11 19~* eoco 0 NA 1.1 - 5.7° 0.01 1 3 5r 1111Ra + D 1 0 0.23 - 4.2 1.5-7.6° 0.15 0.1 0.4 76'- J>>-rti 0.87 0.1 - 3.4 1.1 - 5..,... 0.05 1 3 57"' 131U + D 0.96 0.12 - 3.8 1.5 - 7.7° 0.03 6 14 7.,.

• Using pressurized Ion chamber or Nal scintil1atlon detector

~ Using Geiger-Muller with 30 mg/cmJ tube C 1J7c. without daughters d 131Th + D Sourc~: SC&A 93c, SC&A 93d 1',!ote: This draft Issue paper refms to work In progress by Sanford Cohen & Associates, Inc. which is marked "Prefiminary Draft - Do Not Cite or Ouote." Such information hu been referenced exclusively for the purpose of this draft issue paper which Is understood to be solely for Internal EPA use. C-1

AU..-eTA~LEOAl. eoo-m-osw 1DR11 ~ / ) /

\\ J 1*ffr.:.1':J-l '::1";:0 11 ; l.:l 1 SEtES CON51JLTFf..lT5 '305 764 '3386 P.02/29 t;UMMENTS ON THE NUCLEAR REGULATORY CO:MMISSION'S PROPOSED RULE - RADIOLOGICAL CRITERIA FOR DECOMI\\fiSSIONING Prepared for American Minina Congress Prepared by SENES Consultants Limited 121 Granton Drive Unil 12 Richmond Hill, Ontario L4B 3N4 January 1995

'.::Jt.Nt:.'.::J l... Uf'bUL I HN I :i 305 764 3386 P.03/29

SUMMARY

SENES Consultants Limited was asked to review the dose and residual soil radioactivity implicatiowi of a rule being developed by the Nuclear Regulatory Commission (NRC) entitled "Radiological Criteria for Decommissioning" (referred-to in this document as the NProposed Rule*) and to consider its implications for the Mining Industry. Under existing rules, the NRC approves decontamination and decoromissJoruna of facilities on a site-specific basis. The Proposed Rule requires licensees to decontaminate land& t.o be released for unrestricted~ such that the radiation dose received by critical groups using the lands will not exceed 15-mrr.:~1 p:;r year from residual radioactivity. According to the NRC, the intcmt of the Proposed Rule is to provide ~censees with clear deconlam;natlon objectivea, to reduce the involvement of the NRC in decon'camination plalu, and therefore to expedite decontamination and decommwionin& of sites. Although tbe Proposed Rule suggests that doses from radon (and progeny) are excluded from the 15 mrcm per year limit, the Proposed Rule is unclear as co just what will be done with radon. The Proposed Rule states: "... uposure to radon at decommissioMd sites would M C01Jtrolkd by nqwirins the licensee to reduce the residual concentrations of radon. precw-son Ulce uranium, thorium and radium to uvels within the limit for wirestrlcted us~... " (ie. 15 mrem per year). What does this mean in practice for soil decommissioning level&? In this review, It is shown that, depending on the assumptions made regardin& the use of decontarniuated land, residual excess {i.e. above background) U-238 concentrations (in equillbrlwn with its decay products includin& radium-226) ranging from about 0.5 to 3 pCi/j will be required to comply with the Proposed Rule (assuming radon doses are !Wl included in the 15 mrem/y limit). A level of about 3 pCi/g excess U-238 in soil would also result in indOOI radon concentrations near the EPA action level of 4 pCi/L for indoor radon. If doses from radon and progeny are eventually included, a residual U-238 soil concentration of about 0.2 pCi/g would be required. By compariso11t it should be noted that naturally occurring U-238 and Ra-226 soil concentrations average about I pCi/J acrou the USA. The implications go far beyond the nuclear fuel cycle and potentially impact situations where NORM (a.aturally,uccurring [Bdloactive.materials) are involved. Althou&h beyond the intended scope of this review, concerns over other aspects of the Proposed Rule arc also briefly noted. One important concern is the applicability of an ALARA analysis based oo soutee material originating in the upper 1 cm of the soil when many of the facilltiea re&ulated by NRC {notably uranium milling) have soil contamination extending to depth. The implications of thia assumption also extend beyond the uranium mining and milling sector ro mining in general when concerns over the NORM issues are recognized. SENE, Comuka#e limited

.,1n*, .:..It.I J.;;J~...; .L.l*l!J1 905 764 9386 P.04/29 TABLE OF CONTENTS -Poaet

SUMMARY

1.0 IN"TR.ODUCTION..... * *..............,, ***,,................. *....

• 1 2.0 INTERPRETATION OFnIE PROPOSED RULE FOR RADON.....**..... 2 3.0 IMPUCA TIONS OF PROPOSED RULE ON DECOMMISSIONING OF LANDS AND STRUCTURES ASSOCIATED WITH URANIUM INDUS1'R.Y FACILl'IlE.S. '.**.. I
• ~ ************************* Ill
• s 4.0 DOSE MODEl.LlNG OF DECOMMISSIONED LAND.. *.. *. *. *. *....... 6 4.1 Scenario to be Modelled * *.............. * * *.............. * *
• 6 4.2 Dose F.stimates Based on NURE0-1500............ *.... *....... 6 4.3 Alternative Dose Estimates Based on Reasonable Assumptions.. *.... *.
• 8 4.4 Doses from Radon Decay Progeny *... *.......... *............ 10 4.4.1 Relevance of 15 cm Soil Depth Assumption.... *............ 10 4.4.2 ALARA,,,,,.........,.,. *.................... *...... 11 S.O DISCUSSION.*.............*,...........***,, ***......*,.. *
• 11 6.0 CON~USIONS..........*..*.............*..,............. *. 13 7.0 REFER.EN'CES **......., * *.. *............ * * * *. * * * *.... *... *. * *. 15 TABLE OF TABLES I

Dose Estimates Based on NUREO-1500 2 Do.se Estimates Based on Alternative Model 3 Radon Progeny Doses APPENDIX A: Al~ve. Realistic Residential Model Based on Reasonable Assumptions SBNES Comuhata 1.imilod

SENES Cct-lSJLTANTS 905 764 9386 P.05/2'3 LO INTRODUCTION SENES Consultants Limited (SENES) was asked to review a rule being developed by the Nuclear Regulatory Commission (NRC) entitled "Radiological Criteria for D~commislioning.. and to consider the implications of their lS mrem/y dose limit and corresponding residual soil radioactivity levels for the Mining Industry. Under existing rules, the NRC approve~ decontamination and decommissioning of facilities on a site-specific basis. According to the NRC, the intent of this Rule is to provide licensees with clear decontamJnarion objectives. to reduce the involvement of the NRC in decoptamination plan&. and therefore to expedite decontamination and decommissioning of sites. A participatory rulemaldng process was followed by NRC in drafting this rule throu&h the meana of workshops and the provision of drafts for comment to the public. The Proposed Rule wu published in the Federal Register on August 22, 1994 and comments are invited until early in 1995. In brief, the Proposed Rule requires licensees to decontaminate lands to be released far unrestricted use such that the radiation dose received by critical groups using the lands will not exceed 15 mrcm per year from residual radioactivity. This decontamination objective has potential implications far beyond the nuclear fUel cycle and may impact on situations where n,atarally-2CCUffl!lg radioactive materials (NORM) arc involved. This review comments on aspects of the Proposed Rule related to the proposed do8e, its interpretation in terms *of residual soil radioactivity levels, and its potential impact on decommissioning of mining industry.facilities. Example calculations of the decontamination levels that might have to be achieved are provided. A large number of different decontamination situations will exist in practice. depending on the nature of the facility being decommissioned and the posaible future unrestricted uses for the former facility lands. At one. albeit unlikely extreme. the lands could. theoretically. be used for I 31635 - 10 IUIAl)' 1995

.&.J. -~

JCJ'IC.;::J *...LJN~ I 1-fi I ::::i 905 764 9386 mixed fanning use with the critical ifOUP residing on the land and conswnina a substantial fraction of their diet from food grown on such land, and using water for drinking. crop and food animal irriaation and fish growing. At the other extreme, the nature of the terrain and geographical location could preclude uses other than wilderness recreation or forestry lands.

A reasonably conservative but plausible scenario would be to assume Ie$.idential occupation of remediated lands at a future time. This scenario wa& adopted for illus1rative calculations in this report which demonstrate the significance of how -NRC deals with the radon issue and also provides a concerned basis for ~sslng the reasonableness of the basic NRC exposure pathways calculated. A iln&le family home, constructed on decommissioned former industry land in which no alteration of the relative ratios of uranium and decay progeny ha.a occuned, with some garden-grown produce betn, consumed by the resident& is a.mJmed as the basis for esdmates of the decontamination levels that would achieve the Proposed Regulation'& IS mrem/y dose limit 2.0 INTERPRETATION OF THE PROPOSED RULE FOR RADON On.reading the NRC Proposed Rule *Radiological Criteria for Decommissioning" as published in the Federal Register (August, 1994), it is not altogether clear whether dose.s from radon are included or excluded from consideration. Section 1,, page 43210 of the Proposed Rule indicates that radon doses are excluded, although subject to indirect constraint&. Specifically. the Proposed Rule states that "... the s'tajf do not propose to establish a &eparote standard for radon, ~ad, exposure ta r11dcn at decotnmi33ioned sills would. 1H controlled by requiri11s the Ucensee to rtduce the resi.dual concentrations of radon precursors likt uramum, thorium and radium to ktMu within the limits for unrestricted use and, using thL AU.RA prlncipk, toward levels which are indistinguishable from backgroUlld uwl&" (FR page 43210). If lhere is not a clear relation between radon and its precurBOrs' and if it is difficult to model radon as suggested by NRC, what does the above quote mean? What are the implications foe 2 31635 - 1 !) Jaaaay lffl SENES C~ umlied

xNt:=i WNolJL f Ft-J T5 905 764 9386 P.07/29 decommissioning? 1be Proposed Rule is very unclear about such matters notwithstanding the statement that the NRC intends to issue guidance in suppon of the rulemaking that "will provide liconsees with sufficient infonnation concerning measurement problems that are associated with background radon... ". "Additional comment& are invited with respect to the problem of determining compliance with the NRC's radiological criteria at sites co.ntaminatect with processed radon-bearln&-or-producing materialsn. The Proposed Rule does not specifically and clearly exclude radon (and thoron) from the proposed 15 mremly llmlt. This uncertainty regardin& NRC's approach to regulatory radon is an absolutely essential item for the Uraniwn Industry in particular and mining in general since, if radon progeny doses were to be included in a future revision to this Rule, then the residual contamination levels may need to be considerably lower than otbcrwise. A detailed examination of the Mllllmary and discussion of comments from the workshops in the Proposed Rule reveals the following points relevant to the Uranium Industry in particular (and mining in general): In Section 4, (page 43205) it is stated: "TM Proposed Ruh would establish a dose limit for relea.Je of the sill of 15 miJlirtm per year (mrtm/y) Total FJfectivt Dost Equi-valent (TEDE)for rwduol radioactivity di.stingui.rhabk from. background and rt qui.re that the license~ reduce tlw reJidual radioactivity to As Low As Reasonably Achievable (ALARA).** The 15 mrem/y woold apply to the averaae member of the Critical Group occupying the decommissioned site. In Section I !(page 43209) it is stated that: "The Proposed Ru/1 limit.I t/uJ total ~sun from allpgthwgs (empha8u adtkd) mad. except for w pu1]J(Me of groundwater prouctio,., dfJes not s~ limit! for individual pazhways." 3 31635

• 1!) 1---, 1995 SESES Oi1-.a11 I...iamod

'+/-Nt:.::i Ll.Nol!LIHNTS 905 '"?64 9386 P.08/29 On tlns basis, it would appear that radon doses should be considered given a restriction on total exposure from all pathways. Furthermore, where groundwater pathways exist, iB it NRC's intent to subtract the 4 mrem/y allowance (inclusive of background) for a net 11 mrem/y dose (exclusive of radon)? The NRC states that it: "does not prop<:Jse to esrablish a siparate standard/or ratUJrin (Section 15~ page 43210). The NRC reasons that (1) radon is ubiquitous In the general environment; (2) since large uncertainties exist in models to project radon concentrations in indoor air based on soil concentrations of precursors; and (3) because of limitations of exisling techniques in distingoishing between elevated radon concentrations and radon attributed to natural sources. it is not possible to measure or distinguish concentrations of radon which will produce radiation doses of a few mrem TEDFJy above background usin& current technology. Ins~ Section 15 requires licensee& to control radon by reducing the _residual concentrationa of radon precursors. The discussion in Section 15 is very confusing, since controlling precursOIS.such as radium to levels within 15 mrcm/y does n.Q! control radon to the same level {see Section 4.4 of this report). Although the NRC does not propose to establish a separate standard for ~ the NRC note that the EPA has an action level of 4 pCi/L for radon in buildings. Finally, under discussion of models (Appendix A of NUREG/CR-5512, p. A.18) in resporue to Comment 8, NRC notes: "... The NRC will include criteria for indoor radon measurements in the interim. crluria for unr~stricted use." In our opinion, lhe exclusion of doses from short-lived radon progeny should be stated 4 smms Conmfnq1, LimMd

J t-ir*-c.l::l-l '::l':l5 11 : 03 SENES C~SJL.Ti=NTS 905 764 9386 P.a9/29 unequivocally earlier in the Proposed Rule (and there is precedent for thi8y for example the 2.5 mrcm/y role of 40 CFR 190). If it is not NRC1s intent tba.t radon be excluded from the Proposed Rule, then NRC should clearly indicate w~at risk(&) they do include and how they propose to deal with radon. The comment in Section 11 (page 43209) implies that all.residual radionuclldei and path ways are to be included in the dose summation. which could be taken to include doses from decay progeny such as from radon. Section 11 would be an appropriate place to state the exclusion of radon and pro~ny as an exception (with reference to Section 15 (page 43210)). 3.0 IMPLICATIONS OF PROPOSED RULE ON DECOMMISSIONING OF LANDS AND STRUCTURES ASSOCIATED WITH URANIUM INDUSTRY FACll.lTIES In order to achieve 15 mrem/y to persons occupying decommissioned land. license.es must be able to estimate the concentration of residual radioactivity in the land that would give this dose. In order to detennioe this, models must be set up to predict the dose& that people would receive through the relevant pathways. Various types of former facilities as well as uses for the decontaminated and decommissioned land are possible including agricultural, industrial. comme.tcial, ofrice and residential or all the possible unrestricted uses, subsistence farming is lilcely to produce the highest potential doses to a critical group. In our view, the probability of such a future land use is vecy low, however. A more likely scenario (although still unlikely for remot.e minJna locations) is foe homes to be built on the decontamloatcd land. Due to the high percentage of time occupantS would be on the site, this critlcal group would likely experience the greatest exposures to residual contamination. The residential scenario also is the one in which the potential dose from radon will be most significant due to the accum'Ulation of radon decay progeny in indoor air. Even if radon is not a consideration under the Proposed Rule, the EPA radon action level of 4 pCi/L (EPA 1992) may poac a separate decontamination constraint Perhaps the NRC should make reference to local building codes intended to control indoor radon exposure when discussing thi& Issue. Estimates of the residual excess contamination levels that would meet the Proposed Rule (and 5 3163! - 19 J..wy ]~ SENES o-ultub Umhed

J' * ~~.L _, _,..., .L..L * ~,_)

cNI::. ~ l,IJ"fol.)L I HN I ::i 905 '?64 9386 P. HY29 the EPA radon action level) are made by pathways modelling. Example models and their predictions are described below.

4.0 DQSE MODELLING OF DECOMMISSIONED LAND Modelling of radiological pathways and consequent doses to people coosiatll of three stageS: (1) definition of the scenario to be modelled; (2) the specification of pathways and variables which will determine tbe magnitude of the dose due to that pathway; (3) the selection of the numerical value8 or ranges of values of those variables. 4.1 SCENARIO TO BE MODELLED It is required to determine the excess natural uranium concentration in soil remaining ~ decontamination that would result in 15 mrem per year TEDE (in addition to background) to persons occupying the decontaminated site. For this scenario, a facility is assum~d to have opemted. leaving residual uranium and its long-lived decay products in 1:1 concentration ratloa1* The site has been cleared and decontaminated and made available for construction of single--family residential units of conventional desian, including basements with poured concrete walls and floor. These residences have hack-yard &ardens. which are maintained by the residents and in which garden produce is grown. 4.2 DosE EsTIMATES BASED ON NUREG-1500 In NURE0-1.500, Table A-I, paie A-15, (NRC 1994) doses are calculaied for the residential scenario pathways described in NUREG/CR.*5514 Volume I (NRC 1992). Assuming secular radioactive equilibrium of U-238 and 13 decay progeny in soil with each radionuclide having a concenttation of 1 pCi/g in soil, values of dose may be derived from this t.able for the residential scenario. These are given below in Table l: This j, a~~ am:c tual c:ycle f,ic:illtlcl dawnairam olinmmn irinc1 alld mill, pmar:a rcfJ ed an.A.iam c:,,,p.rmct from 1b pt181n)'). 6 3163.!

• J91aamry 1995 SENES Cam-ahuu umilal

_.. II,.

=..,ic.,

.J...).J.....) J..1. t llJ _I 905 764 9386 P.11/29 Tablt l DOie Eathnat. Ba.sod on NUREG-1!00 Pathway I Dose from ~i/g in son °' u. 238 plu8 l g aK:b ot Iona-lived p,-opiny {mremly) Extem:11 dose 3.15 lnhalatloo dose 0.41 Ingestion dose 22.S Soil ingc:uion dose 0.1 fu1&alion/drtnklng Water 0.01 Aquatic food 0.01 Total 26.8 Hence the maximum concentration of U-238 in soil lO achieve the Proposed Rule IS mrem/y dose limit is 1512.6.8 x 1 z: 0.6 pCi/J. This residual excess concentration represents just over one half the averaae soil backJP'ound U-238 concentration across the USA. Note that ingestion is the largest contributor (94%)_ to dose. Note also that this does not include the dose from radon tl[:Oaeill-According to NRC calculatiom (Table 1), food inaestfon is the largest dose contributor, followed by external gamma. For practical purposes. the other pathways are inconsequential. The scenario used in NUREG-1500 i& based on the default parameters given in NUREO/CR-5512 (NRC 1992) which assumes that an area of 2500 square meters is sufficient to support 25% of the dietary requirements of one adult. The diet and associated variableS described in NUREGICR-S.512 Volume 1, Table 6.23 is assumed. ThlB diet includes a full range of food types includina above-ground and root vegetables, cereal, fruits, beef, fish, dairy products, eggs and chicken. This is lliccly to be quite conservative. Thus, the NUREG-1500 scenario is reminiscent of a rural farming or partly subsistence lifestyle which represents, in our view at least, an extreme of residential scenarios. With a comparatively large fraction of total diet being arown on soil with residual contamination and with firlgation water from contaminated sources. it is therefore not surprising that ingestion pathways will comprise a large fraction of the total dose from residual excess contamination for this scenario. 7 31635

• 19 1-y l~

SENBS CoDRllt1111t1 Limited

x:.J*lt..::. l..uN::iJJL I f-r~ I :::i 905 764 9386

?.1~-29 If a fully subsistence farming situation (100% of diet from local sources) is within the conceivable land use scenarios, then by simple proportion. the dose from 1 pCi/g of U-238 would be about 95 mremlyear and the residual excess U-238 concentration could not exceed 0.16 pCJ/g of U-238 (not including dose from radon). In one other, more likely respect. however. the NUREG-1500/ NUREG/CR-5512 Volume I, Table 6.23 assumptions may not be realistic for some remediation situations. ThiB concerns the assumption that the residual contamination is in the top 15 cm of soil (the plow depth). Other depth assumptions will impact external dose in and outside of a home and may also affect radon concentrations. 1bis is an important assumption for mining type operations. It is important to note that a 15 cm thick source is not realistic for mining si~tlons. Use of more.realistic scenarios would alter the dose calculations and greatly affect the volume of materials involved in decolllIIliMioning and hence, the potential risks and costs associated with decommlssi.oning. 4.3 ALTERNATIVE DoSE EsTIMATES BASED ON REAsONABLE AssUMPTION.S In a typical residential situation, it is unlikely that grains, meat. milk, milk products, chickeia and eigs will be grown for consumption by the critical,group in their domestic gardens. If these diet.ary items are not assumed to originate from remediated lan~ a less conservative but potentially more realistic scenario can be modelled. Furthermore, allowance can be given for washing and other reduction of contamination of leafy vegetables and fruits during food preparation and cooking, and irrigation of garden produco with non-contaminated water. It is also excessively conservative to assume that contaminated groundwater provides the drinkin& water source as well as water in which fish are grown for consumption. Unfortunately the NUREG-1500 computer model is not presently available to permit as to examine the detailed calculations and intermediate results and to perform sensitivity analysis by varying the assumptions. We have therefore carried out an alternative simplified scoping pathways analysis based on reasonable assumptions to independently determine the magnitude of the residual W'an.ium concentration that would meet the Proposed Rule for a realistic, less conservative.residential scenario than that assumed in NUREG~ISOO. This pathways analysis, 8 31635

• 19 Jamacy 1995 smms Couu1taDU Limlccd

=t::.rt::i ~

I f-N I :i 905 764 9386 P.13/29 If a fully subsistence fanning situAtion (100% of diet from local soutces) is within the conceivable land use scenarios, then by simple proportion, the dose from 1 pCi/g of U-238 would be about 95 mrem/year and the residnal excess U-238 concentration could not exceed 0.16 pCi/g of U-238 (not including dose from radon). In one other, more likely respect. however. the NUREO-1500/ NUREG/CR-5512 Volume 1, Table 6.23 assumptions may not be realistic for some remediation situations. This concerns the assumption that the residual concamination is in the top 15 cm or soil (the plow depth). Other depth usumptions will impact external dose in and outside of a home and may also affect radon com:enuations. This is an imponant assumption for mining type operations. It is important to note that a 15 cm thick source is not realistic for mining situations. Use or more realistic e scenarios would alter the dose calculations and greatly affect the volume of materials involved in decommissioning and bcmce, the potential risks and costS associated with decommis&ioning. 4.3 ALTERNATJVB DoSE EsTIMATES BASED ON RBAsONABLB ASSUMPTIONS In a typical msidentlal situation, it is unlikely r..hat iJ1UDS. meat, milk. milk products, chickens and egas will be grown for consumption by the critical group in their domeslic gardens. If these dietary items are not assumed to originate from reme<liated land. a less conservative but potentially more realistic scenario can be modelled. Furthermore. allowance CM be given for washin: and other reduction of contamination of leafy vegetables and fruirs during food preparation and cooking, and irrigation of garden produce with non-contarnfnat.ed water. It is also excessively conservative to assume that contaminated groundwater provides the drinking water source as well as water in which fish a.re grown for consumption. Unfonunately the NUREG-1500 computer model i& not presently available to permit us to examine the detailed calculations and intermediate results and to perform sensitivity analysis by varying the amunptions. We have lhen:fore carried out an alternative simplified scoping pathways analysis based on reasonable assumptions to independently determine the magnitude of the residual uraniwn concentration that would meet the Proposed Rule for a realistic, less conservative residential scenario than that assumed in NURE0-1500. This pathways analysis, 8 llffl

• 19 I---, 1995 SBNBS ComlllllCU lllded

SENES CONSLLTANTS 905 764 9386 P.14/29 which is described in detail in Appendix A. is based on a model previOUJly used by SENES Consultants Limited for l1cveloping cleanup criteria for radium contaminated land. The results of this analysis shows that a residual excess concentration of U-238 in soil of about 3 pCi/g would meet the Proposed Rule 15 mrem/y TEDE to a residential critical group. (This would not include radon progeny ~posures a.s appears to be the jntent of the NRC rule). The results of this analysis are aiven in Table 2: TKblel Dose F..attmata Based oa Alttnuatbe Model Using Reaaozlable Auwnptioqs Pathway Dose from l pC111 lb &oil al 0-238 plua l pCllg eacb of Joag-Uvecl progeny (l'DffilV'J) Adult -CbUd External (IOff 2.3 4.0 lnhalaliOO dose 0.2 0,1 Inaestion dose 1.9 0.8 Soil inge$tiOO do6e 0.1 0.3 Total 4.5 S.2 Hence. the maximum concentration of U-238 in soil to achieve the Proposed Rule lS mrem/y dose limit for this scenario is 15/5.2 x I :112.9 pCi/g. This excess concentration represents about three ti111C$ the average soil background U-238 concentration across the USA, The' major differences between the NURE0-1500 dose estimates and the alternative model concema food pathways. NURE0-1500 assumes the full set of default assumptions of NUREG/CR-5512 regarding the occupational scenario with 25 percent of food groups being grown locally on lBnd with residual ~cess contamination. This produces a dose from ingestion some ten times 2teater than the alternative model. which assumes a limited reliance on garden produce. The alternative model, does not assume that grain, animal or animal products are grown on remediated land and consumed by the residential critical group. 9 SBNES er-ileutt I..lmiCed

,t:.Nt:~ IJ..JN=,(.Jl.. 1.-N I '.::i 905 764 9386 P.15/29 4.4 DosES FROM RADON DEC.A Y PRooENY Estimates of the short-lived radon progeny exposures corresponding to a concentration of 0.6 and 2.9 pCYg are provided in the table below for comparison purposes, (Detailed calculatl.oll8 are provided iD Appendix A). Also for comparison, the doses <includin& radon progeny exposures) that would result to the same critical jroup from USA-average natura1 background U-238 soil concentrations of l pCi/g are estimated These estimates (rounded) are given in Table 3.

Table 3 Radon Progeny Doaas Conantratioa of Adalt Dose Cblld Dole U-:ZJ8 in soil (pCl/g) (mretufynr) (mmn/yoar) 0.6 30 40 l 50 70 2.9 ISO 210 It is noted that if radon progeny doses were to be included in the dose SWlU1lation for a 15 mrem dose limit, a residual excess contamination target of about 0.2 pCi/g sail U*238 (and progeny) would be required. This is a factor of (about) 15 below the 3 pCi/g concentration without radon proaeny doses considered (Section 4.3). e 4.4.1 Relevance of 15 cm Soil Depth Assumotlon It should be noted that in Table 3 it is assumed that the U-238 is unifonn1y distributed in the soil. including that surrounding and beneath the basement walls and floor of a home. This will produce the maximum indoor radon concentration. This is a realistic assumption for decommi&sionins of mining sites. It was noted lhat the NUREG/CR-5512 default parameters assume the thickness of the surface-soil layer to be 15 cm (the plow layer). A 15 cm contamjnat.ed soil layer thickness around a home would obviously have less but still significant impact on indoor radon concentrations. 10 3163$ - ]Q laaua,y 1995 SENES a:-l1m11 l.Jmhed

JRN-20-19'35 11 : 05 SB-ES CCNSULTi=t,,iTS 905 764 9386 P. 16/29 4.4.2,ALARA For ieasons that are nol clear from the NRC docwnentation, the NRC make a different assumption about soil contaminalion for their ALARA. llllalysis. The soil depth affected by residual excesa contamination will be highly dependent on the nature of the former facility and the nature of the decontamination and remediation undertaken. The only situation where a 15 cm contaminated soil layer thickness would seem approprlat.e i& for virgin - farmland. where the source of contamination 18 dustfall. or where contaminated topsoil has been spread. Under realistic situations. where burial and mixing occur, the contamination is likely to extend beyond the 15 cm surface layer. According to NRC the initial soil contamination resides within the top 1 cm of soil, and only dcwnward migration by water produces contamination at depth (GEIS, Vol. 2. Section C.5.4 NUREG 1496). This artificially results in a soil profile that ls totally dependent on cootamJnant migration. which is why the ALARA analysis is insensitive to lower dose limits Le. why soil volumes and costs don't change significantly. In real situations, of interest to mining, contamination levels are more a fW1cti.on of historical waste management practices (e.g. bDrial, soil mixing through previous site activities. etc.) than slow cqntaminant migration with time although this is a factor also. Under such more realistic scenarios, clean-up costs would increue rapidly with decreasfug residual dose criteria. This would also increase the conventional risks associated with decommissioning. 5.0 DISCUSSION In order to comply with the NRC ~posed Rule (and exclusive of radon), residual U-238 co11taroloadon level& between about 0.6 and 3 pCi/g in the soil (in addition to the prevailing local background soil concentration) mast be achieved to permit single family home construction and occupancy. It is demonstrated that the target decontamination levels predicted by models is highly dependent 11 SENES C.oamltaillS Limiwd

~t.f\\E.5 CONSULT~TS 905 754 9386 P.17/23 on the assumptions made. In the NUREG-1500 scenarlo. doses from food ingestion predominate. This comes about because of several more conservative assumptions than the alternative realistic model. Toe major conservatisms in the NURE0-1500 model are: (a) food ln&1'8tlon appears to include a full range of foodstuffs including grain, meat. ens, milk and milk products. (b) contaminated ground water is used to irrigate J:arden-grown food. The NRC Proposed Rule in Section 15 (page 43210) states that "expo.run 'to radori at lhcommisl*ioried sites would be con-trolled by rtquiriltg ~ /.ice,ase~ to reduc:6 the residual concentra1ions of radtm precursors Uh uranium, thorium and radium to levd1 within the limlt for unre3tricud use and, usbig die AURA principle. toward levels which are indistinguishable from background leve'ls." NRC states (Section l.S page 43210) that since "limitations of ailting techniques in distinguishing betweBJ1 ekvatt1d radoti coricentradons and rcuw11 atlribu~ to natural sources... " "... it is not (therefore) possible to measure or distinguish co11centration.r of radon which will produce radimlon doses qf a few mrem (emphasis added) TEDE/y abov~ background using c:urre,u uchnology." In the scenario modelled in this review, doses from radon progeny are clearly more than "a few mrem" when the 15 mrem/y limit of the Proposed Rule is met for radionuclides other than radon and progeny. Radon is in fact. the predominant source of dose. Thus. questions could be.nused whether d058S of this magnitude meet the intent of the Proposed Rule. It is noted that the average soil U-238 concentration in the USA is I.0 pCI/g [Myrick ct al_ 1983]. For a residual excess U-238 concentration of 2.9 pCV1 (LOLal 3.9 pCVg including the avcra&e natural background U-238 concentration). the "rule of thumb" (that 1 pCi/g in soil of U-12

'305 764 9386 P. 18/29 238. in equilibrium with its progeny, produces 1 pCi/L in homes), predicts an indoor radon concentration of about 3.9 pCi/L. The EPA radon action level is 4 pCi/L. Thus the EPA radon action level may impose an additional constraint on site decontamination. effectively Urnitiag the total U-238 (and Iona-lived decay progeny) to a total of 4 pCi/g.

6.0 CONCLUSION

S

1.

The Proposed Rule is somewhat va~e reaarding radon, The exclusion of radon PfO&eUY doses in the 15 mrcm/year dose limit should be stated unequivocally early in the text of tbe Rule. Precedent ex.is~ for this approach, for example, the 25 mremly rule of 40 CFR 90.

2.

Dose modelling of residual U-238 and decay progeny radionuclides (excludlnJ short*livcd radon decay progeny) shows that in order to comply with the Proposed Rule for the occupants of a single-family home built on decontaminated facility land, residual excess U-238 soil concentrations will range from about 0,6 pCVg to about 3 pCi/g depenclinJ on the degree of co~atism assumed for the modelling. The value of 0.6 pevg would apply to an unlikely scenario in which the critical group derived a significant fraction of their total diet from residually contaminated sources. The value of 3 pCi/g would apply to a more reasonable, but still conservative residential scenario. Ho'W'eVer, where the groundwater pathway applle~ it is not clear whether the dose limit for remaining pathways (exclusive of radon) would be reduced to 11 mrem/y or not; irrespective of what the actual dose from this pathway was.

3.

For a very unlikely subsistence farming use of remediated land. residual excess contamination level8 of about 0.15 pCi of U-238 per gram of soil would be required to comply with the Propose<! Rule.

4.

Doses from radon decay progeny appear to be excluded from the Proposed Rule's 15 mrem/y limit. The EPA radon action level of 4 pCi/L in homes would, however. provide a separate constraint on decontamination, since this concentration would be 13 lltM - 19 IUIW)' 1951:5 SBNBSa-ullamU!Dtod

905 764 9386 P. 19/29 produced by a total U-238 soil concentration of about 4 pa/g. Since the natural background U-238 soil concentration across the USA averages 1 pCi/g, the residual excess U-238 in soil concentration would be limited to about 3 pCi/g (less in areas where higher lhan average narura1 U-238 concentrations exist). S. Should radon progeny doses be included in the dose summation in a fucure revision of the NRC Rule, decontamination targets would need to be set at about 0.2 pCil& of U-238 (in equilibrium with daughters) in soil in cases where homes could be constructed over such soil. 14 31635

• 19 Juuary 1~

SENESa-iwuJ.JmiMid

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• l!JtJ

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I ~ 905 764 9386 P.20/2:9 7.0 REFERENCE'S Environmental Protection Agency (EPA) 1992. Techriical support Docwnent for tM Cititen's Guid~ to Radon. Offlce of Radiation and Indoor Air, Washini(On, D.C. (EPA 400-R 011); May 1992. Federal Register 1994. Volume 59, No 161, Monday August 22, 1994. International Commission on Radiological Protection (ICRP) 1993. Proiection again.ft radon* 222 at Mm£ and at work. ICRP Publication 63, Annals of the ICRP: 23 (2). Myrick. T. E., B.A Berven and F.F. Haywood 1983. Determination of Conctntro.tu:ms of Selected RadionucUtks in Surface Soil in du U.S. Health Physics Vol 45 No. 3 pp 631-642 National Council on Radiation Protection and Measurements (NCRP) 1987. Exposur~ of du population in the United S~s and Canada from natural background rodlarion. NCRP Report No. 94. Nuclear Regulatory Commission (.NRC) 1994. General Environmental Impact Staumem iii Suppon of Rukmaking on Radiological Crit4riafor Decommissioning of NRC - Licensui Nuclear Facilitus. NUREG-1496, Vol. 1, August. Nuclear Regulatory Commission (NRC) 1992. Residual Radioactive Contaminalion from Duommissicming - Tecfuiical Basis for Translating Contamuuzlion Levell to Anmull Total Effective Dose Equivaknt. NUREG/CR-5512 PNL-7994. Vol 1, October. Nuclear Regulatory Commission (NRC) 1994. W orldng Draft Regulatory Guide on Release Criteria for De.comrnissionin,i: NRC Staffs Draft for Comrnen.t NURE0-1500. lS

it::.NE5 OJN5UL Ti::t-JTS 905 764 9386 P. 21/29 SENES Consultants Limited 1992. Re-examination of clean-up criteria for soils ccmtaminaud with radlum or arsmic, December 1992. Prepared for the Low-Level Radioactive Waste Management Office (Canada).

16 31635

• 19 l4lluvy l!m SENBS C'-Oo,nkaot1 ~

~Nt::, u...JN::il...JL I HN I :i ~::, * (64 3386 P. 22/29 APPENDIX A ALTERNATIVE, RESIDENTIAL MODEL

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'305 764 '3386 P,2]/29 APPENDIX A: ALTERNATIVE, REALISTIC RESIDENTIAL MODEL The NURE0-1500 residential scenario uses a worst-case set of pathways and comervative ~pUons. If the low~lilccllhood pathways arc omitted and some parameter values are chosen to be more realistic. a modified scenario can be modelled (SENES 1992). NUREG/CR.-5512 recommended parameter values have been used in a number of instances. A 1 PAtHWA YS CONSIDERED The significant exposure pathways considered were:

1.

Exposure to gamma radiation from residual uranium and long-lived decay progeny.

2.

Inhalation of soJI dust inside and outside of the home.

3.

Consumption of food vegetables grown in the back-yard garden.

4.

Ingestion of soil from the back-yard. In addition, exposure from the inhalation of radon progeny was con&idered ~ a comparison with exposures from other sources. A.2 PATIIWAYS NOT CONSIDERED

1.

Ingestion of water. Excess uranium and decay products were not e.swmed to impact drinking water supplies.

2.

Inhalation of radon* decay progeny ou~lde the home. Radium in the soil in lhe vicinity of a home will produce radon in the outside air. Wind will rapidly disperse such radon originating from the reclaimed area so that very little radon progeny from this source will be present in the air oulSide the home. 1 31635 - 19 IUIQl[J l99S

J HN-~-13'35 11: 07 SHES CONSl.fl.... TFt,jTS 905 754 9386 P.24/29 I I' A.3 PARAMETER V AUmS SELECTED Parameter values used in the model were selcct.ed to be realistic bat conservative values and were taken from previous similar pathway analyses carried out by SENES but using, whercvar approp.riat.e. values recommended in the ~port nR.esidual Radioactive Contamination from Decnmmtsstonina - Technical Basis for Translating Contamination Levels to Annual Total Effective Dose Equivalent 11 - NUREG/CR-5512 Volume 1. (NRC 1992). Where ranges of possible vallle$ exist. a single value near the upper range of possible values was used. Th.Ls will result in dose& calculated by tho model being above the averaje value that would likely apply to the critical group being modelled (Le. a reasonable worst-case situation). This is judged to be appropriate for a screening calculation. More sophisticated probabilistic modeling techniques arc available, if required, to estimate the probability associated with a particular calculated dose, and farther consideration could be given to the choice of appropriate parameter values. Values of parameter values used in this modeling process are given below. It should be noted that the in&estion and inhalation dose conversion factors given in NUREG/CR-SS 12 are used in the calculations, however, these dose conversion factors do not provide separate factors for adults and children or for soluble and insoluble physical/chemical farms of radionuclide&. Furthermore. these dose conversion facwrs are derived from ICRP-26 recommenda.tions which have been superseded. More recent dose conversion factors arc available from ICRP and other authorities. A.4 MODELING PR.ocEss A computer spreadsheet was set.up in which the doses from individual pathways were calcu1Atcd and tbe total dose summed. Toe input value of uranium-238 residual excess concentration in soil was adjusted (a) to the value of the soil concentration which produces a dose to the adult or child of 15 rnrem/y (whichever is limiting); (b) a value. of 1 pCi/g~ which corresponds to the USA-wide average for natural U-238 soil concentration (Myrick et al. 1983). 2 '31635 - J9 Juaary l~ Sl!NU O:wahuu Um.ltocl

I I ~5 754 9386 P.25/29 A5 PARAMETER VALUES AsSUMED Values of pawneter values used in the modeling ~ were selected to be realistic but conservative values and were taken wherever appropriate from a repon uResi.dual Radioactive Contaroinodon from Decommissioning - Technical Basia for Translating Contamination Level3 to Annual Total Effective Dose Equivalent"- NUREO/CR-5512 volume I. (NUREO, 1992). In other cases parameter values are selected on the basis of reasonableness. ADULT.RECEPTOR CBAJtACTERJsncs Body wei&)lt (tg) 70 AalmDCCl* Air lntate rate: indoon (m.1/h) 1.2 NUREOICR.-5512 OU!dool'3 (ms/h) 1.2 NUREG/CR.*SS 12 PrOllucehltabratc: above-ground (kj/y) 124 A~ below.ground Cka/y) 79 AssorneM' Fractioo of time spent at site 0.67 A aaurneci* Fraction of ala, time lndooJ3 0.965 Assamed* Fr.aotioa of de time outooon 0.035 >JIIDDCd* Hours per day womin: m garden 8 As111roed-Dayg per weet woddn8 in garden 1 Assumed" Weeks per :,ear wortiog in garden 26 Agsum,ed* IIOUl'I per year wotking tn prdcn 208 ~ Dirt ln&csted when ootdoots (mg/8 h day) 480 NUREG/CR-5512 Annual a~e tn,vstton (mi/(lay}= 34.2 CHILD RECEPl'OR CHARACTERISTICS Body weight (kg) 20 Auumerl* Alr intake rate: indcxn (m:s/h} o., AABQJIYld* outdoors (m'lb) 0.8 .A$$01Md" Produce intab rate: abov&-poond (kg/y) 60 Aumo,,,,_ below-around (kg/y) 24 A*wmocr F:n!letioo of tuna spent al lite 1 Acvnned* Ft'Ddi.cn of iitc time lndocn 0.881 AsllUIDed* Fmcdoa of stte time OUldoon 0.119 Asmn1c-Ar Hom per day playing in yard 8 Ju.~ Days per weet playing in yard 5 MS!JIIN"AP Weeb per year playin& In yam 26 Aau,....,..C,- HOUB pu year playin, iD yard 1040 AJSUIDC44' Dirt iD&e&t?d when oUldoon (mg/8 b day) 2SO As8'~ Annual avcrqe ingestion (mg/day)= 89 3 3163.~ - 19 I~ 1995 s.ENBS Qwnltaal 1.W

J n1, c..u .1. _, :.;...J

l..l.

• w::J r

=i*1t:.::, l-UN:=i,__,L I HN I o ROUSE; DATA Radon/radon c1aughtl!r equ:lllt.ium fraction CONTAMINAnON DATA Outdoor tOlal dust concent.ratlon (Jlg/m3) Outdoor au3t durln.g gardening Cootmninated fractloo or alrborne d'IM Contaminated fraction of airborne dust during &ardeollli F'racdon ol outdo(x dust indoor.. Respirab1c ffflClico of airborne d~ EXl'ERNAL GAMMA EXPOSUJUt Emmal DCF (µSv/h per Bq/g) {U-238 + proeeny) Reduction factor when lndoon FOOD DATA Fraction of cootaminatlon remaining !!Oer food prep abovc-grwnd cont bclOW-grovnd cont Fraction of l)t'Oducc from site ll'OLIAR DEPOSmoN FACTORS ~doa velocity (mis) Initial. f'ractioo of du.t intercepted Pn,duce yield (g/m~ Weatbmng conslant (1/o) V egewion l[Owth period (d) 305 764 3386 P.26/23 0.4 100 500 0.5 0.9 0.15 0.15 0.3 0.33 0.5 l 0.25 0.01 0.2 1400 0.05 60 NCRP NURBGICR-5512 NUREG/CR.-5512 MaOIDe<t- ~ Assumed* A38umed* Derived from NUREGICR-5S12 NUREGICR-5Sl2 A.uumed"' .Asq1owr-A"'-1~ ~~ AJi.smnfliP The deposition rate of contaminated dust to vegetation (DR) is calcuJated as: Deposition velocity x ouJdoor dust concentration x contaminated fraction of outdoor dust x concentration in soil (JJq/m 2/a) \\,-- The vegetation concentration due to deposition (Bq/ g) is: DR >< initial fra~n of dust intercq,ted >< (1-e C-wsJhtma colUtlllJI x ~ pi.fit.,,,W, produce yield x weathering constant 4 31(133

• 19 I lJll.l&r)' lggj SENES Coui1tuu Umiltd

Jnl~-..:.1:.J-.l=::) .l].il::Jtj x.Nt.!::i lUN5l..lL TRNTS 905 764 '3386 P. 2'7 /29 SOIL-TO-PLANT TRANS~ 1{ FACTORS The following dry weight soil-~plant transfer factors (NUREG/CRSS12) were assumed: RIWlionuclld= U-234 U-238 Th-230 RA-226 Pb-ZIO Po-210 Soll to plant 0.017 0.017 0.0066 0.01, 0.0058 0.0025 ttaDSfer factor Dry to wet weisJit factor. 0.25 (comcrvauvoly IIUUDled) (NUlWOJCR5512

• otbCr vegolablcs)

RADIATION DOSE CONVERSION FACTORS The following radiation dose conversion factors [NUREG/CR-5512] were assumed for adults: (units - µSv/Bq) R.adiowclide U-234 U-238 Th-230 Ra-226 Pb-210 Po-210 Inpstioo 6.88E-02 7.66&02 l.48E-01 3.58E-Ol 1.45E+OO 5.148-01 Inbalation I 3.20E+Ol ) 3.58E+o1 i 8.80E-t-Ol 2.32E+-OO 3.67E+OO ~1

• asaumed value based oo judgment of reasonablo vllhlc appllcable to sceuarlo.

RADON DECAY :PROGENY EXPOSURE (NCRP 1987) The indoor concentration of radon progeny is determined from the empirical relationship that 1 pCi of U-238 per gram of soil produces, on average about 1 pCi/L of Rn-222 or 0.004 WL 9 in the air inside & home at a 40% equilibrium of radon and progeny. RADON DOSE CONVERSION FACTOR FOR RADON DECAY PROGENY (ICRP 1993) The followin1 relationship was assumed: Adult& and children: 4 mSv (400 mrcm) per WLM. A.6 MoDELINo REslJLTS Detailed results are provided in Table A-1 Percentage contributions are given in Table A-2. s 31W

• 19 Tamry I~

SENl!S CODlultall&l limiled

~,...,,..- J. ::;,:,;:i J. J. i IJt:!

it::N:::::i W~UL f RN TS 905 754 9386 P.2sag i..,

Table A-1 Doses to Residential Critical Group from 1 pCl/a: each of U-238 and Progeny ADOLT :RECEPTOR-SOIL U-238 CONCENTRATION: Pathway U-238 extt.mal: outooora. inOOOJ'S tnhalndon: outdoon 0.10 .indoon o.~ produce: above-,ground 0.34 below-sround 0.21 dirt mgestioo 0.03 Total 0.91 ~ ~e!}f ~~!21auon: 1 tiCi/g soil -> 1 ~ Rn-222 indoors ioooor air oonc (pCllL)a llldoor equilib fraction: mdoOr air cone (WL)=. i.ndoot air Wl.poiUl'e {WLM)::o Occupancy amustea indoor air (Wl...MJ Amrual dose from progeny (mrem) ~ U-234 0.11 0.25 0.38 0.24 0.04 1.02 l 0.4 0.004 0.21 0.13 53 Th-230 o.z, 0.62. 0.29 0.18 om 1.43 CHILD RECEPTOR* SOIL U-238 CONCENTRATION: P..tlhway Dose (µSv/y) U-238 U-234 extemal: O\\ltdoons indoon h:ibatation: Oaldoots 0.04 indoon 0.13 produce: above-ground 0-16 below-ground 0.06 dirt ingestion 0.08 Total 0.48 ~ rtf'J: ~?D ;L J I -l, -*-.c I 82003 ~~ Secretary U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Attention: Rulemaking and Adjudications Staff Gentlemen: DOCKETED OCT - 6 1997 RULEMAKINGS AND ADJUDICATI iTAFF s~ 1 ,* r \\Cl\\ I ~, I v

Subject:

Comments on Radiological Criteria for License Tertiu'1mm : Uranium Recovery Facilities (Frderal Register Volume 62, Number 139, Monday, July 21, 1997 pages 39093 - 39095) The Wyoming Mining Association (WMA) is an industry association of mining companies and associates (suppliers, contractors, service companies, vendors, etc.) in the State of Wyoming. The WMA's membership includes a number of uranium recovery licensees licensed by the Nuclear Regulatory Commission. The Wyoming Mining Association has reviewed the above described Federal Register notice and has the following comments: General The WMA has commented previously on this issue, specifically in a letter dated December 15, 1994 on the March 1994 proposed rule and on the draft proposed decommissioning standards. Those comments are incorporated by reference. The WMA supports the proposed radiological criteria for uranium and thorium decommissioning standards. In addition, the WMA believes that uranium recovery facilities have certain unique characteristics, including the fact that the target radionuclides are naturally occurring.

1.

Site Locations Uranium recovery sites are predominately located in Texas, Colorado, Nebraska, Utah, Wyoming arid New Mexico, in rural areas with low population densities. In some cases, the nearest town may be miles away. Uranium mill sites, with their associated tailings impoundments, will be turned over to the Department of Energy or State for long term care. Residual radionuclide concentrations at uranium recovery sites pose little or no risk to the public due to the sites' isolation and, in the case of uranium mill sites, continuing control by a governmental agency. d 'I car................*..*.*.

U.S. NUCLEAR HEGULATORY cm,M!SSION F:. i.1:MP,~:~;Ge & ADJUDICATIONS STAFF c,r:,=,c -OF THE SECRET.A ;y o,: THE CO.. M:2S!O ~

Secretary - USNRC Page 2. Comments on Radiological Criteria for License Termination...

2.

Targeted Radionuclides The radionuclides targeted for cleanup at uranium recovery sites are uranium, thorium and radium. These are naturally occurring radionuclides which can be found in varying concentrations in natural materials over the face of the Earth. There is significant variability in background radionuclide concentrations from place to place. Thus, any imposed cleanup standard must: Account for naturally occurring background concentrations, and account for the great variability in background concentrations and the resultant doses from these concentrations Background soil concentrations of uranium, thorium and radium vary widely as do the potential doses resulting from them. This is especially the case with uranium recovery facilities since many were constructed adjacent to deposits of uranium ore. Some of these deposits were discovered through their surface outcrops which means that very high concentrations of uranium, thorium and radium existed naturally at the surface near these facilities and are part of the natural background concentrations for the site as a whole. WMA believes that background is a very important issue, and encourages NRC, with industry input, to develop a guidance document on determination, of site specific background or other implementation issues for this regulation.

3.

Solely Account for Contamination from NRC Licensed Materials and the Doses Related to Them and Not from Other Activities At or Near the Site Decommissioning standards for uranium recovery sites must only regulate cleanup of NRC licensed material and not mining which is not regulated by the NRC. Proposed Regulation The Wyoming :Mining Association supports the approach suggested by NRC in the Federal Register. Specifically it is WMA's position that:

1.

The current cleanup standard for radium in soils as defined in 40 CFR 192.32 and-.10 CFR 40 Appendix A and its associated dose should remain as it exists today.

Secretary - USNRC Page 3. Comments on Radiological Criteria for License Termination...

2.

The dose standard for radium-226 should be used as the dose standard for the cleanup of natural uranium, thorium-230 and thorium-232 contamination due to byproduct contamination from licensed uranium processing operations. The Wyoming Mining Association appreciates the opportunity to comment on this matter. If you have any questions please do not hesitate to contact me. Sincerely, WYOMING MINJNG ASSOCIATION Marion Loomis Executive Director K:\\OFFICE\\ WPWIN\\ WPDOCS\\1. 4A3.SEP cc: Katie Sweeney - NMA Anthony J. Thompson - Shaw, Pittman, Potts and Trowbridge Crew Schmitt - UPA Jon lndall - UP A

Sweetwater Uranium Facility Kennecott Uranium Company 42 Miles NW of Rawlins P 0. Box 1500 Rawlins. Wyoming 8;>301 (307) 328-1478 Fax (307) 324-4925 DOCKET NUMBER PR,,.,.-0 J-Lf o PROPOSED RULE..!,.!.!....;~;;._--= C6 :L F tz 39013) ([) 6 October 1997 Kennecott Secretary Ener~.,____ U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 DOCKETED OCT - 6 1997 Attn: Rulemaking and Adjudications Staff Gentlemen:

Subject:

RULEMA.'-<!NGSANO ~ AOJUOlOAl'-!0NSSWF SEGY-NRO Comments on Radiological Criteria for License Termination: Uranium ~- Recovery Facilities (Federal Register Volume 62, Number 139, Monday, July 21, 1997 pages 39093 - 39095)

• , ';)

Kennecott Uranium Company is a uranium recovery licensee. Kennecott Uranium Company is the operator and manager of the Sweetwater Uranium Project located in Sweetwater County, Wyoming. Kennecott Uranium Company has reviewed the above described Federal Register notice and has the following comments: General Kennecott Uranium Company has commented previously on this issue, specifically in a letter dated December 15, 1994 on the March 1994 proposed rule and on the draft proposed decommissioning standards. These comments are incorporated by reference. Kennecott Uranium Company supports the proposed radiological criteria for uranium and thorium decommissioning standards. In addition, Kennecott Uranium Company believes that uranium recovery facilities have certain unique characteristics, including the fact that the target radionuclides are naturally occurring. These issues must be addressed prior to the promulgation of any specific cleanup criteria for them. These unique circumstances are described further in the text of this document. Current Regulatory Situation The standards for radium cleanup are described in 10 CFR 40 Appendix A and 40 CFR 192 which set the limits for radium concentrations above background. 40 CFR 192.32(b)(2) states: The requirements of 192.32(b)(l) shall not apply to any portion of a licensed and/or disposal site which contains a concentration of radium-226 in land, averaged over areas of 100 square meters, which as a result of uranium byproduct material does not exceed the background level by more than: (I) 5 picocuries per gram (pCi/g), averaged over the first 15 centimeters ( cm) below the surface, and Kennecott Uranium Company 1s Manager of the Green Mountain Mining Venture f tlf:'T r 3 1 1J!17 Ac ledged by card........................ - Kennecott Energy Company provides marketing and other services on behalf of Cordero Mining Company. Antelope Coal Company, Spring Creek Coal Company and Kennecott Ura,.um Company.

u.s. NucLEAR REGULATORY caMMissioN RULEMAK!NGS & ADJUDICATIONS STAFF OFF!CE OF THE SECRETARY OF 1HE COMM!SSION Po.:tl'T'cirk D2te ~ er / t:; 1 C'.:l~i&s Rt1cci*J;~cl __._ ______ Add'I C"l"ics Rc,1*v; d,,,_,__. - Spct,i.;.I o;:;:,.t *t'c1 H 1:>I ~,.., 1 c ~t~ Ct:>tr:Jc fi,

Secretary - USNRC Comments on Radiological Criteria for License Termination... (h) 15 pCi/g, averaged over 15 cm thick layers more than 15 cm below the surface" Similar language is contained in 10 CFR 40 Appendix A Page 2. The standards for the cleanup ofTh-230 and uranium (U-238 plus U-234) were discussed by Dr. Elaine Brummet ofNRC at a ~ing ofNRC staff and uranium recovery licensees in October 1995. Specifically, at this meeting the following standards were descnbed and were stated to be based on past practices for Title I sites: Subsurface Th-230 with Ra-226< 5 pCi/g - 35 pCi/g based on 1000-year Ra-226 of 15 pCi/g U-238 pins U-234 with daughters at background - 35 pCi/g based on Option 1, depleted uranium (bone dose) Site Locations Uranium recovery sites are predominately located in Texas, Colorado, Nebraska, Utah, Wyoming and New Mexico, in nrral areas with low population densities. In some cases, the nearest town may be miles away. Uranium mill sites, with their associated tailings impoundments, will be turned over to the Department of Energy or State for long term care. Residual radionuclide concentrations at uranium recovery sites pose little or no risk to the public due to the sites' isolation and, in the case of uranium mill sites, continuing control by a governmental agency. Targeted Radionnclides The radionuclides targeted for cleanup at uranium recovery sites are uranium, thorium and radium. These are naturally occurring radionuclides which can be found in varying concentrations in natural materials over the face of the Earth. There is significant variability in background radionuclide concentrations from place to place. Thus, any imp0sed cleanup standard must:

1.

Account for naturally occurring background concentrations The standards for radium cleanup in 10 CFR 40 Appendix A and 40 CFR 192 clearly state that the limits are for concentrations above background. Language from 40 CFR 192.32 (bX2) relating to radium-226 cleanup is cited earlier in this letter. Similar language is contained in 10 CFR 40 Appendix A Any soil concentration standard for other radionuclides must clearly state that it is for concentrations above background.

2.

Account for the great variability in background concentrations and in the resultant doses from these concentrations Background soil concentrations of uranium, thorium and radium vary widely as do the potential doses resulting from them. This is especially the case with uranium recovery fucilities since many

Secretary -- USNRC Page 3. Comments on Radiological Criteria for License Termination... were constructed adjacent to deposits of uranium ore. Some of these deposits were discovered through their surface outcrops which means that very high concentrations of uranium, thorium and radium existed naturally at the surface near these facilities and are part of the natural background concentrations for the site as a whole. Often the background concentrations of these radionuclides vary widely, from very high at surface ore outcrops to low in areas up gradient from these outcrops. Thus, uranium recovery sites often have by default, a very large natural variability in background concentrations of radionuclides in soil. This variability in background is often so great that the twenty-five (25) millirem dose standard for decommissioning of licensed facilities would be indiscernible in the natural variability in background at a uranium recovery site. The table below lists some background concentrations of some radionuclides in soils at some sites in Wyoming. SITE UMETCO/GAS HILLS High Low Mean RED DESERT, WY High U-nat Cone. (pCi/g) 213.0 1.3 18.0 88.0 SWEETWATER URANIUM PROJECT IBgh 9.4 Low 0.13 Mean 2.44 ND= No data Th-232 Cone. (pCi/g) 16.0 0.7 2.2 ND ND ND ND Th-230 Cone. (pCi/g) 594.0 1.0 10.0 ND 4.27 0.14 1.57 Ra-226 Cone. (pCi/g) 535.0 1.0 10.0. ND 4.48 0.05 1.44 Notes: 1) Concentrations ofradium-226 and thorium-232 in outcrops and soils for the UMETCO/Gas Hills operation are courtesy of John Hamrick of UMETCO Minerals Corporation. This data has been previously submitted to the NRC and to members of the Environmental Protection Agency's (EPA) Science Advisory Board (SAB).

2)

The high concentration of uranium in soil in the Red Desert is from Geological Survey Bulletin 1030-I, Reconnaissance Study of Uranium Deposits in the Red Desert, Sweetwater County, Wyoming and is from a sample taken at Lost Creek Bluff listed in Table 7.

3)

Concentrations of uranium, thorium-232 and radium-226 in surface soils at the Sweetwater Uranium Project are from Final Design Volume VI, Existing Impoundment Reclamation Plan, which has been submitted to the NRC.

Secretary -- USNRC Comments on Radiological Criteria for License Termination... This table shows extreme variability in natural background concentrations in radionuclides in surficial materials. Radium-226 concentrations vary from 0.05 to 535 pCi/g ( over four (4) orders of magnitude). Uranium concentrations vary from 0.13 to 213 pCi/g (over three (3) orders of magnitude. Thorium-230 concentrations vary from 0.14 to 594. pCi/g (over three (3) orders of magnitude). Thorium-232 concentrations vary from 0.7 to 16.0 pCi/g (over one (1) order of magnitude). The table below shows the great variability in dose which could result from these extreme differences in natural background. The table below lists a low potential dose using the low concentrations and a high potential dose using the high concentrations of background radionuclides in areas around uranium recovery sites: Low High U-nat (mrem/y) 0.1 165.3 Th-232 (mrem/y) 1.2 27.2 Th-230 (mrem/y) 0.80 3415.5 Ra-226 (mrem/y) 0.13 1428.40 Total (mrem/y) 2.23 5036.40 Note: The dose conversion factors used in this table are from NUREG-1500, Working Draft Regulatory Guide on Release Criteria for Decomm~ioning: NRC Staff's Draft for Comment, and are as follows: Thorium-232: Uranium-nat: Radium-226: Thorium-230: 1.7 E+oo mrem/y/pCi/g 7.76 E-01 mrem/y/pCi/g 2.67 E+-00 mrem/y/pCi/g 5.75 E+-00 mrem/y/pCi/g (NUREG-1500) (NUREG-1500) (NUREG-1500) (NUREG-1500) The concentrations and related potential doses are extremely variable and the twenty-five millirem dose standard for other sites is indiscermble in the variability of background at uraniwn recovery sites and in areas around them.

3.

Solely Account for Contamination from lle2 Byproduct Materials and the Doses Related to Them and Not from Other Activities At or Near the Site Decommissioning standards for uranium recovery sites must only regulate cleanup of NRC licensed ore processing activities and associated 11 e2 byproduct material and not mining which is not regulated bytheNRC. 10 CFR40.13 (b) states: "Any person is exempt from the regulations in this part and from the requirements for a license in section 62 of the act to the extent that such person receives, possesses, uses, or transfers unrefined and unprocessed ore containing source material; provided, that except as aµthorized in a specific license, such person shall not refine or process such ore."

Secretary -- USNRC Page 5. Comments on Radiological Criteria for License Termination...

4.

Many licensed uranium recovery operations are located near uranium ore bodies, outcrops of uranium ore and former uranium ore haulage routes. As such, any decommissioning standard must take into consideration this fact, and materials not regulated by NRC, such as ore, cannot be included in any determination of dose or concentration used to satisfy decommissioning requirements. Some uranium recovery sites are located downwind of open pit mines or ore piles not regulated by the NRC. In addition, some uranium recovery facilities were built on bases of low grade ore used as construction base or fill Ore in these above descn"bed circumstances is often impossible to differentiate from co:rrtam:ination related to the licensed processing of somce material. These non-NRC regulated materials should not be included in the decommissioning standard, concentration or dose. Account for the Risks of Cleanup Cleanup is not a risk free activity. There is a real risk in moving significant amounts of soil in terms of construction accidents. The risks to workers from heavy construction activities have been well documented. The risk is approximately 6.9E-8 per worker-hour (2'.ak: 1997) while the risk oflost-time injury is l.6E-5 per worker-hour (Givens, 1997). These are real quantifiable risks as opposed to the risks oflow level radiation at doses below 10 rem which have not been demonstrated. (ICRP 1991). These real risks of injury or death from clean up operations should be factored into the promulgation of any target radionuclide soil cleanup concentration. The risks to workers from construction accidents during soil cleanup operations should be weighed against the risks from any possible exposure to radiation. Proposed Regulation The Kennecott Uranium Company believes that the approach suggested by NRC in the Federal Register notice would be adequate. Specifically, Kennecott Uranium Company's position is as follows:

1.

Radium Standard The current cleanup standard for radium in soils as defined in 40 CFR 192.32 and 10 CFR 40 Appendix A and its associated dose should remain as it exists today. The current cleanup standard for radium-226 according to "... Calculations done by EPA in support of 40 CFR part 192 indicated that the dose from radium, excluding radon, was approximately 0.6 mSv/yr (60 mrem/yr).... " This fact is not an obstacle to the existing radium-226 standard because as the NRC states: In actual practice, cleanup ofuraniwn mill tailings resuhs in radium levels lower than 10 CFR Part 40 standards, and radium is usually removed to background levels chning cleanup of uranium and thorium to levels in existing NRC guidance documents."

Secretary - USNRC Page 6. Comments on Radiological Criteria for License Termination... The dose standard for radium-226 should be used as the dose standard for the cleanup of natural manium, thorium-230 and thorium-232 contamination due to byproduct contamination from licensed uranium processing operations as well.

2.

Proposed Uranium and Thorium Standards Kennecott Uranium Company proposes that the dose above background for radium-226 embodied in the radium-226 soil cleanup standard (5/15 rule) should be used on a site specific basis, taldng into account applicable pathways, models used and present and projected use of the site and surrounding area, to calculate natural uranium, thorium-230 and thorium-232 soil cleanup concentrations above background for the given site. Thus, the dose from radium in 1 OCFR40 should be used as a benchmark for the cleanup ofradionuclides other than radiwn-226, such as thorium-230, thorium-232 and natural uranium at uranium recovery facilities. This site specific methodology, using the calculated dose from application of the 5/15 rule to the site and applying that dose to natural uranium, thorium-230 and thorium-232 is the only means that will account for the unique characteristics of ea.ch site. Sites vary greatly in their remoteness from habitations and in the specific pathways applicable to a given site. Do to these facts, different sites will have differing soil concentrations for natural uranium, thorium-232 and thorium-230 associated with a given dose. Regulatory Consistency This methodology uses the same dose criteria as was used to develop the radium standard and are consistent with that standard. In fact, it extends the dose used for determining the radium-226 standard to other radionuclides on a site specific basis. Conservatism Since "radium is usually removed to background levels", and ALARA is applied to the cleanup of uranium recovery sites the uranium and thorium would be remediated to near background levels resulting in low doses from these radionuclides. In addition, in regard to conventional mill sites, substantial portions of these sites must be turned over to a custodial agency (the DOE or the State). Some of this area, due to the requirement to include areas underlain by groundwater plumes addressed under Ahernate Concentration Limit (ACL) applications, will undoubtedly include remediated surface contaminated areas which now would be permanently under agency control effectively eliminating them as potential sources of exposure.

3.

Determination of Background Background levels of radionuclides in soils vary widely from site to site and between different areas within a single site. It is Kennecott Uranium Company's position that a single value for background for each licensed site does not reflect natural conditions. Kennecott Uranimn Company believes that licensees should be able to assign different background values for different areas on a give site to properly reflect the natural distnbutioit of radionuclides in soils and outcrops.

Secretary -- USNRC Page 7. Comments on Radiological Criteria for License Termination...

4.

Application Solely to 11e2 Byproduct Material Contamination Resulting from Licensed Activities '5. Kennecott Uranium Company believes that it m~ be made clear in any new regulation that the standards for natural uranium, thorium-232 and thorium-230 apply solely to the clean up of contmrrination generated by NRC licensed operations and not from mining or other types of operations which may yield surface contamination. Support for Regulatory Guidance on :Uackground Determination Kennecott Uranium Company supports the Wyoming Mining Association's request for input in and development of regulatory guidance on background determination and other implementation issues for this regulation at uranium recovery sites. Kennecott Uranium Company appreciates the opportunity to comment on this matter. If you have any questions please do not hesitate to contact me. Oscar Paulson Facility Supervisor C:'OFFICE\\WPWIN\\WPDOCS'D6AOCT cc: Bob Green Jolm Trummel

NUCLEAR REGULATORY COMMISSION 10 CFR Parts 20 and 40 RIN 3150-AD65 [7590-01 -'?61CKETED 1JSNRC

• 97 JUL 22 A10 :55 OFFICE nF SECRETARY oocKL. Tl \\lG & scRv1cr Radiological Criteria for License Termination:

BF.11 C-i Uranium Recovery Faci lities DOCKET NUMBER AGENCY: Nuclear Regulatory Commission. PROPOSED RULE PR ~o 1-1 o ( t, ~ t=R3 'I09~ ACTION: Request for additional comment on uranium recovery facilities.

SUMMARY

The NRC is requesting specific comment on radiological criteria for license termination for uranium recovery facilities. This action is intended to provide full consideration of the issues associated with the decommissioning of these facilities and the regulatory options for resolving these issues. (0~ ft,, 1qq,., DATES: Submit comments by (~Rsert dete 75 day! after puelicatieR d~te). Comments received after this date will be considered if it is practicable to do so. but the Commission.is able to assure consideration only for comments received on or before this date. ADDRESSES: Send comnents to: Secretary, U.S. Nuclear Regulatory Commission. Washington. DC 20555-0001. Attention: Rulemakings and Adjudications Staff. Hand deliver comments to: 11555 Rockville Pike. Rockville. Maryland. between 7:30 am and 4:15 pm on Federal workdays.

criteria of the rule would apply to the facility but not to the disposal of uranium mill tailings or to soil cleanup. The proposed cleanup rule (§ 20.1401(a)) referred to 10 CFR Part 40. Appendix A. where criteria for disposal of mill tailings and soil cleanup of radium already exist. The public corrment period for the proposed cleanup rule closed on January 20. 1995. Cooments received on the proposed rule were summarized in NUREG/CR-6353. C011111ents on the criteria in the proposed rule were received from over 100 organizations and individuals representing a variety of interests. Viewpoints were expressed both in support of and in disagreement with nearly every provision of the rule. Specifically with regard to uranium mills. coounents on the proposed rule generally agreed with the exclusion for disposal of mill tailings and soil cleanup. These commenters recorrmended that the rule also exempt conventional thorium and uranium mill facilities and in situ leach (ISL) (specifically uranium solution extraction) facilities from the scope of coverage because they stated that the decorrrnissioning of these sites is covered by Appendix A to 10 CFR Part 40 and 40 CFR Part 192. In responding to the comments on uranium mills during preparation of the final cleanup rule. the Commission considered appropriate regulatory options for addressing requirements for cleanup of soil. buildings, and groundwater at uranium and thorium mills and ISLs (collectively referred to as UR facilities) for unrestricted release of the site other than the tailings disposal and reclamation which are subject to the requirements of 10 CFR Part 40. Appendix A. In considering regulatory options for establishing radiological criteria for license termination of UR facilities. it is important to understand current regulations applicable to remediation of both inactive tailings sites. 3

j for these and other radionuclides. There is not a similar need to address codifying requirements for groundwater at UR facilities because 10 CFR 40. Appendix A. as adopted by NRC to confonn to EPA regulations in 40 CFR 192. already specifies groundwater cleanup standards applicable to tailings impoundments and also* specifies that standards at UR facilities for groundwater cleanup from sources other than the tailings impoundment can be determined on a site-specific basis. Cleanup of radium to the concentration standards noted above would generally result in doses higher than the 0.25 mSv/yr (25 mrem/yr) unrestricted use dose criterion of the final cleanup rule. Calculations done by EPA in support of 40 CFR 192 indicated that the dose from radium. excluding radon. was approximately 0.6 mSv/yr (60 mrem/yr) (the final cleanup rule notes that doses from radon would be controlled by cleanup of radium which is the principal precursor to radon). In actual practice. cleanup of urani,um mill tailings results in radium levels lower than the 10 CFR Part 40 standards. and radium is usually removed to background levels during cleanup of uranium and thorium to the levels in existing NRC guidance documents. As noted above. the Corrrnission considered including criteria in the final cleanup rule for radionuclides other than radium (primarily uranium or thorium) that would be present in UR facility site areas proximate to locations where radium contamination exists (e.g.. under the mill building, in a yellow cake storage area. under/around an ore pad. and at ISLs in soils. where spray irrigation has occurred as a means of disposal). In this approach, the standard of the final cleanup rule would apply to radionuclides other than radium. while the 10 *cFR 40. Appendix A. standard would continue to apply to radium. However. as discussed in the ftnal cleanup rule. published 5

y these facilities. A way to address this situation could be to establish a criterion whereby the dose from all radionuclides at UR facilities. including radium. ts set at levels different from either the final cleanup rule or the standards in 10 CFR Part 40. 'This would involve modifying the radium standards of 10 CFR Part 40. Appendix A. However. a difficulty with this approach is that the radium cleanup standard of 10 CFR Part 40. Appendix A. confonns to EPA's cleanup standard for uranium mills. and per UMTRCA. the authority to set such cleanup standards for uranium mills rests with EPA. kl approach for setting dec011UT1issioning criteria for UR facilities. which has been developed in response to the corrments received on the proposed rule. would be to codify a dose objective for radionuclides other than radium in soil and buildings at UR sites consistent with the radium cleanup standard already in place for those sites in 10 CFR Part 40. Appendix A. and 40 CFR Part 192. Under this approach. UR facilities would use the dose from radium in existing 10 CFR Part 40 as a benchmark for the cleanup of radionuclides other than radium. Thus. in this approach. the criterion for cleanup of radionuclides other than radium from buildings and soils could be set such that it resulted in a dose no greater than the dose resulting from cleanup of radium contaminated soil to the standard specified in Criterion 6(6) of 10 CFR Part 40. Appendix A. Use of this approach would thus allow for consistent criteria to be app1i~ across site areas. III. Request for Additional Comments on Regulatory Options The Commission is reopening the public coovnent period specifically to solicit additional cooments on the specific standard that should be used*for 7

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