ML20199E744
| ML20199E744 | |
| Person / Time | |
|---|---|
| Issue date: | 01/28/1998 |
| From: | Greeves J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Berube R, Fitzgerald J, Weinstock L ENERGY, DEPT. OF, ENVIRONMENTAL PROTECTION AGENCY |
| References | |
| REF-WM-3 NUDOCS 9802020240 | |
| Download: ML20199E744 (5) | |
Text
.______ _____ ___________- _ - _ -
.]l January 28, 1998
Dear Members of the Interagency Steering Committee on Radiation Standards:
Enclosed is the December 12,1997, letter from Nuclear Regulatory Commission Chairman Shirley Jackson to Environmental Protection Agency Administrator Carol Browner concerning EPA's guidance entitled, " Establishment of Cleanup Levels for CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act of 1980) Sites with Radioactive Contamination." Tt.is' letter is provided for your information. Call me et (301) 415-7437 if you have any questions or comments on this letter.
Sincerely,
[0riginal signed by)
John T. Greeves, Director Division of Waste Management Office of Nuclear Material Safety and Safeguards
Enclosure:
- December 12,1997 letter cc:
Vicki Lloyd, EPA /ORIA John Karhnak, EPA /ORIA Stephen Luftig, EPA /OERR Colonel Robert Cherry, DOD/DNA Andy Wallo, DOE /EH-41 Jefirey Synder, DOL / OSHA Rick Boylc, DOT i
Carrie Jelsma, OMB Miriam Forman, OSTP gfg DISTRIBUTION:
3 Central File NMSS r/f DWM r/f EDO r/f L LDP r/f
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MKnapp VHolahan HNewsome FCameron KStablein MBell JHolonich RBangart FCardile SMcGuire gm.3 RJohnson CPrperiello CJones MFederline CTrottier DOCUMENT NAME: S:\\DWM\\LLDP\\ PAS \\lSCORS.LTR
- See previous concurrence OFC LLDP LLDIY[
LLDP4-vl DWM-f NAME PSobel*
RNe$ son Jhey
[hNes' DATE 1/J(V98 1//h/98 1/M96 k 1/28/98 OFFICIAL RECORD COPY PUBLIC:
YES 1 NO _ Category: Proprietary _ or C.: Only _
ACNW:
YES 1 NO _
IG:
YES _ NO 1 Delete file after distribution: Yes _ No 1 ll11!Il l'I!!lllIll Il
,eo202o2.o,ee 2e NRC F1F @MEB COPY PDR WASTE WPt-3 PDR o
January 28, 1998
Dear Nmbers of the Interagency Steering Committee on Radiation Standards:
Enclosed is the December 12,1997, letter from Nuclear Regulatory Commission Chairman Shirley Jackson to Environmental Protection Agency Administrator Carol Brcwner concerning EPA's guidance entitled, " Establishment of Cleanup Levels for CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act of 1980) Sites with Radioactive Contamination." This letter is provided for your information. Call me at (301) 415-7437 if you have any questions or comments on this letter, Sincerely,
[0riginal signed by]
John T. Greeves, Director Division of Waste Management Office of Nuclear Material Safety l
and Safeguards
Enclosure:
December 12,1997 letter t
cc:
Vicki Lloyd, EPA /ORIA John Karhnak, EPA /ORIA Stephen Luftig, EPA /OERR Colonel Robert Cherry, DOD/DNA Andy Wallo, DOE /EH-41 Jeffrey Synder, DOL /OCHA Rick Boyle, DOT Carrie Jetsma, OMB Miriam Forman, OSTP DISTRIBUTIQR:-
Central File NMSS r/f DWM r/f EDO r/f LLDP r/f MKnapp VHolahan HNewsome FCameron --
KStabbin MBell JHolonich RBangart FCardile SMcGuire RJohnson CPaperiello CJones MFederline CTrottier DOCUMENT NAME: S:\\DWM\\LLDP\\ PAS \\lFCORS.LTR
- See previous concurrence LLDh LLDP& r/
DWNL- //
OFC LLDP NAME PSobel*
RNe$ son Jhey d'hieees' DATE 1/J(V98 1//h/S8 1/ I /98 E 1/28/98 OFFICIAL RECORD COPY PUBLIC:
YES 1 NO _ Catepry: Proprietary _ or CF Only _
ACNW:
YES 1 NO _
IG:
YES _ NO 1 Delete file after distribution: Yes _ No 1
458"%
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.t UNITED STATES 3
j NUCLEAR REGULATORY COMMISSION W ASHINGTON, D.C. 2055fM)001 f
Janua,y 28, 1998
Dear Members of the Interagency Steering Committee on Radiation Standards:
Enclosed is the December 12,1997, letter from Nuclear Regulatory Commission Chairman Shirley Jackson to Environmental Protection Agency Administrator Carol Browner conceming EPA's guidance entitlea, ~Establ:shment of Cleanup Levels for CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act of 1980) Sites with Radioactive Contaminatioaf This letter is provided for your information. Call me at (301) 415-7437 if you have any questions or comments on this letter.
Sincerely, b
/ John T. Greeves, Director Division of Waste Management Office of Nuclear Materiel Safety and Safeguards
Enclosure:
December 12,1997 letter cc:
Vicki Lloyd, EPA /ORIA John Karhnak, EPA /ORIA Stephen Luftig, EPA /OERR Colonel Robert Cherry, DOD/DSWA Andy Wallo, DOE /EH-41 Jeffrey Synder, DOL / OSHA Rick Boyle, DOT Carrie Jetsr.1a, OMB Miriam Forman, OSTP l
k
QlSTRIBUTE TO:
Mr. Lawrence Weinstock, Director Office of Radiation and Indoor Air (6601J)
U.S. Environmental Protection Agency 401 M Street, S.W.
Washi.79 ton, DC 20460 Mr. Michael Schaeffer, Chairman U.S. Department of Defense Radiation Research and Policy Working Group Defense Special Weapons Agency 6801 Telegraph Road Alexandria, VA 22310-3398 Mr. Raymond P. Berube, Deputy Assistant Secretary for Environment U.S. Department of Energy Washington, DC 20585
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Mr. Joseph E. Fitzgerald, Deputy Assistant Secretary for Worker Health and Safety U.S. Department of Energy Washington, DC 20585 Dr. Adam Finkel, Director Health Standards Programs, N-3718 Occupational Safety and Health Administration 200 Constitution Avenue N.W.
Washington, DC 20210 Mr. Alan Roberts Asso:iate Administrator for Hazardous Materials Safety Department of Transportation, Room 8422 400 Seventh Street, S.W.
Washiryton, DC 20590 Dr. Bruce Wachholz, Chief Radiation Effects Branch P;
National Cancer Institute Executive Plaza North, Suite 530 Bethesda, MD 20892 Dr. Marvin Rosenstein Center for Devices and Radiological Health Mail Code HFZ-60 b
Food and Drug Admiristration 16071 Industrial Drive Gaithersburg, MD 20877 M
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_Mr. Art Fraas Office of Management and Budget Room 10202 New Executive Office Building Washington, DC 20503 Dr. Beverly Hartline Office of Science and Technology Policy 17th & Pennsylvania Avenue, N.W.
- Washington, DC 20500 Dr. Jill Lipoti, Assistant Director for Radiation Protection Programs Division of Environmental Safety, Health and Analytical Programs Department of Environmental Protection CN 415 Trenton, NJ 08625-0415 t
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UNITED STATES k
NUCLEAR REGULATORY COMMISSION
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- et WASHINGTON, D.C. 3GNHOQ1 D
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December 12, 1997 l
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The Honorable Carol M. Browner Adminstrator U.S. Environmental Protection Agency W O--7-s D.C. 20460
Dear Admimstrator Browner:
in August 1997, we received a copy of OSWER No. 9200.4-18 entitled "Establienment of Cleanup Levels for CERCLA Sites with Radioactive Contamination.' The stated purpose of the document is to provide darifying guidance for what the U.S. Environmental Protection Agancy (EPA) asserts would establish protective cleanup levels for radioactive contamination et Comprehensive Environmental Response, Comt ensation, and Liability Act of 1980 (CERCLA) sites.
A specific point made in the CERCt.A guidance is EPA's determination that the dose limits in the U.S. Nuclear Regulatory Commission's (NRC) final rule on " Radiological Criteria for License Termination * (issmd July 21,1997), generally will not provide a protective basis for establishing preliminary & mediation goals for cleanups at CERCLA sites and that NRC sites cleaned up to the 25 mrom/yr all-pathways criterion will have to be remediated further to meet the CERCLA and National oil and Hazardous Substances Pollution Contingency Plan requirements to be protective. This guidance also seeks to impose the 15 mremlyr and separate groundwater requirernents contained in the EPA draft cleanup rule vntlurawn by EPA from the Office of Management and Budget in December 1996. These statements are of specific concem to us for several reasons.
First, this approach esults in the impusition of the CERCLA risk range on radic,nuclides without the informed and open discussions that would be part of the rulerr.sking process to estaollah such radiation protection stande,de-a process which NRC recently completed.
Secondly, the Commission's final rule is based on considerations of rial, radiation protection t
principise, national and intomational standards, and costs compared to eseociated benents of cleanup. In leeuing the rule, we concluded that the innel rule not only protects public health and estety, but alas estabilohes the framework to address the umited number of difficult comes whbh would otherwtoo requite n by-m esemptions. We housve this approach not only achieves cost effective regulation and adequata protection of public heelth and esfoty and the environment, but also is based on sound poucy.
Tne third reason for our concem is that the CERCLA guidance talees questions regarding the innably of Econes termirntion declaions and poseble EPA adions at sitec that have corr.pl. led with the NRC or equivalent Agreement State cleanup standants and had their licenses terminated On August 5,1997, I transmitted a draft Memorandum of Understaryiing (MOU) between our agencies that addresses these finality issues. The purpose r.f the MOU,
' Cons.dtstion and Fhalay on C =,iM4 and Decontamination of Contaminaind Sites.'
is to prowde for finality in NRC IMonoe termination decistoria in onier to provide liconeses and D2%3DNF 9Pr' Enclosure
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m the putdic with a stable and predictable regulatory framework that is adequately piveve of public beshh and safety and the environment. Further, the MOU is intended to provide for earfy consultation with EPA in those osses where a site's residual all pathways dose exceeds 15 mrom/yr.
We have speelnoally examined the statements in the CERCLA guidance that assert the NRC rule is not protoceve, and we find a number of theti to be inaccurate, misleading, or inconsistent with nabonal and intomational standards. The NRC staff reviewed associated EPA documents and rationale one I have included the details of these sesff finomgs in an enclosure to this letter, We have not received a response either to the general issues raised in our August 6,1997 notter or to the specmcs ef the MOU. We fully intend to proceed, and have proceeded, with implomontabon of the Juh 21,1997 final NRC rule, both in preparation of regulatory guidance for the rule s..a in application of the rule for specmc cases. In addition, as you are probetly awam, we have sought legislation that would recognize the validity and adequacy of NRC's cleanup sale and ensure finality for NRC and Agreement State licensees.
sincerely, Original signed by Shiricy Ann Jackson Shirley A7n Jackson
Enclosure:
Discussion of NRC Concems With EPA's CERCt.A Guidance Originating OfRee: EDO/RES SAJ - Approved Ref: CR g7-207 GJD TraveVstaff-Commlesion Correspondence no comments NJD-Approved EXM - ApproveWedits
- OFC, SEQY OCM/SAJ l
NAME M 1
DATE 12/1M OrrICML REGORD CCPf
i DISTRIBUTION FOR LETTER:
LETTER TO: HONORABLE CAROL M. BROWNER FROM:
SHIRLEY ANN JACKSON DATED:
12/12/97
SUBJECT:
CERCLA GUIDANCE C. Paperielb E. TenEyck D. Cool C. Haughney J. Greeves C. Jones C. Trottier l.
S. Treby i
C. Cameron N. Costanzi M. Knapp J. Mu phy M. Federline M. Weber J. Hickey R. Nelson M. Bell K. Stablein
' J. Holonich R. Bengart, OSP
')
D. Matthews, NRR R. Blough, R-l D. Collins, R-il C. Pederson, R-!Il R. Scarano, R.IV r
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! IEC:19.1997 2:31PM NO.925 P.14 Discussion of NRC Concems_with EPA's CERCL A Gul4nce With regard to specific issues on the protectiveness of the NRC standard, we have reviewed the CERCLA guidance and find that the statement in the CERCLA guidance that the NRC rule is not protocuve to be inaccurate. The NRC sta# reviewed associated EPA documents and rctionale. The staff findings are described in detail below.
1.
EPA's derivation of 1E 4 as a protective value appears to be a policy judgment, and le inconelatent with international findinge.
The CERCLA guidance indicates thrst a risk level of 1E.4 is a level of protection that is not to be exceeded' and that the 25 mrom/yr does cnterion in NRC's final rule is not protective because it would exceed that level. A rationale for EPA's value of 1E 4 con be found in a Endstal Ramister notice (FRN) for EPA's ' National EmWon Standards for Hazardous Air Pollutants (NESHAPs)* under the Clean Air Act (54 FR 38044, September 14,1969). The FRN notes that in the Mnyt Chloride decision [ Natural Resources Defense Cour cll, Inc. v.
EPA. 824 F.2d at 1148 (D.C. Cir.1987)], the EPA was direded to determine inn acceptable..
risk level based on a judgment of what risks Ne ' aces ptal:la in the worid in which we live'.
l In response to tne Mny! Chionde decision, the FRN iticicates that EPA.:ompileo a review of societal risks to place risk estimates in perspective and to provide background and context l
for the EPA's judgment on acceptability of noks 'in the world in yd- 'h we live'. The FRN states that individual risk of premature death in EPA's survey t a from 1E-1 to 1E 7, and that the level of approximately 1E 4 is within the range for indivdual risk in the survey and at a value that comports wtth many previous health risk decisions by EPA. The EPA risk value le applied in the CERCLA context (see 55 FR at 8715 (March 8,1990)].
The intomational Commission on Radiation Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP) use a drffetent approach from EPA in setung an acceptable risk level.' ICRP and NCRP are organizations whicn are chartered, and intomationally recognized, for the development of basic radiation protMon standards.
Their findings are contained in ICRP Putcleation 80 and in NCRP No.118, respectwely.
Based on their review of health and societal lasues, both documents (while nd$ing the difUculty of setting standards for en ' acceptable" public dose limit) arrive at 100 mrsm/yr as a level that is acceptable for exposure to radiation courous o%r then medecel procedures.
NCRP 116 notes that this value includes a review of risks of mortality faced by the public.
The ICRP and NCRP approaches further reduce their 100 mremlyr limit by the principle of
' optimization," which includes considerations of constraints (e.g.,26 mromlyr) and cost-eneceveness.
Also. EPA's use of the 1E-4 risk level is somewhat inconsistent with its own Federal Radiation Protection Guidance for E=="re of the General Public (FRG) as published for comment on December 23,1994. Speci6cally, the FRG h consistent with the
' As discussed in item 3. below, EPA has determined that 3E-4 is "essentietty equivalent" to 1E 4.
8 As Attachment B to EPA's August 22,1997 CERCLA memorandum statue. EPA has sujected the NCRP approach to standards setting which EPA correctly notes NRC uses.
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2 recommendations of ICRP and NCRP, in that, FRG recommendation no. 3 endorses an annual public dose limit of 100 mrom/yr and recommendation no. 4 indicates that indvidual sources of radiatk>n exposure should have "authortzed limits" set at a fraction of the 100
- m. rom /yr. The FRG further states that setting such limits will oiten necessarit be based on broad judgments which may leso to somewhat higher values with further implementation of the AL. ARA procoes. While the FRG does not recommend a specific level for any one source, it does cite authorized EPA and NRC standards for certain sources that currently exist, including 40 CFR Part 190 for the uranium fuel cycle and 10 CFR Part 61 for low-level weste disposal, botn of wh'M set authvized fractions at 25 mrem /yr.
Using the principles of setting of " Individual does and risk limits" and "optirntzation of protection" (noted abovd and an additional margin to allow for the potential for exposure to more than one radiation source, the NRC issued a fir:al rule on radiologimi criteria for license termination. The rule includes an alkpathways dose critetton of 25 mrom/yr and further reduction based on ALARA (62 FR 39058, July 21,1997).
The EPA approach uf setting an acceptable risk letelin the context of reviewing risks acceptable in society is sim!!ar to that followed by ICRP and NCRP, but, clearly, is no more scientifically credib;e than the ICRP or NCRP reports. The FRN on NESHAPs acknowledges that because of the uncertainties over nealth effects EPA's decision will depend to a great extent on policy judgment. Therefore, there is no reason to conclude that risk limits set through EPA's procen are any more appropriate for protection than those set by ICRP and NCRP nor is there a rosson to conclude that NRC's rule is not pmtective. EPA's simple declaration that NRC's rule, developed through extensive rulemaking in accordance with the procedures of the Administrative Procedures Act and detalled analysis and evaluation,is not adequately protective is unsupported and scientifically unsound.
2.
EPA inaccurately states that NFLC's rule is not protective The CERCl.A guidance does not address several items which will further lower the eshmated risk from the impierrentatk.a of NRC's rule. These items are inherent either in the NRC rule or in the characteristcs of radioactive mateVs and imiude the following:
a) the requittewnt in the NRC rule that doses be reduced below the rule's dose criterion through the Al. ARA ('as low as reasonably achievable"; defined in 10 CFR Part 20) process further lowers the risk for the large ma}ority of NRC sites; b) radioective decay of key contaminant nuclides which, for the large number of NRC fealities with contaminent rCes with half-lives equal to 30 years or less, will result in noduction of the risk near or below that which EPA aitaMy decieres to be protective; and c) the uncertainties associateo with e.ueuig risks from radiation at such low does levels. Although NRC Indicated in ths FRN for its final rule (at 62 FR 39062) that It was not altering its policy regarding use of the linear non threshold model as part of the rutomaking, the FRN also stated that there are uncertainties as to wtwther adverse radiabon effects occur at all at the low levels of radiobon being h==ad.
The actual risk from 25 mram/yr hi well within the boundarios of scientfic uncertainty j
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regarding the magnitude of the actual health effects at these low de.es. Whether or not health effects result fmm a dose as small as 100 mrom/yr is uncertain, as evidenced by the fellovnng statement of the Committee on the Biological Effwets of lonizing Radiation (BElfs V) in its 1990 report:
Studies of populations chronically exposed to low-level radiation, such as those resirting in regions of elevated naturel background radiation, have not shown consistent or mnclusive evidence of an associated increase in risk of cancer.
This name point was made in a recent safety evaluation report for National Aeronautice end Space Administration (NASA) Cassini mesion fJuly 31,1997), thet EPA participated in, which referenced a Healtn Physics Socoty position noting that for a lifatime does *oelow 10 rem the risk of heall. effects are either too small to be observed or are non existent." Further, the Cassini report concluded that at the low indMdual dow rates expected that there is a high probability there
- vill be no resultant latent cancers.
3.
epa inconsistantly uses its protective value of 1E 4 The CERCLA guidance states that the 25 mromtyr dose criterion in NRC's rule results in an estimated lifetime risk of cancer incidence of SE 4 and that this is not protective compared to 7
1E 4. On the other hand, the CERCLA guidance states that a 15 mromtyr dose standard (estimated lifetime risk of cancer incidence of 3E 4) ja acceptable because *3E 4 is essentially equivalent to the pmoumptively safe level of 1E-4".
The CERCLA guidance statements are inconsistent and raise two specific issues First, it is not apparent why one value would be considered unacceptable while the other is acceptable even though both exceed the 1E 4 risk level. Second, EPA uses cancer incuknce to assess acceptability of the radiation dose levels compared to thu 1E 4 value, even though the FRN l
on NE3 HAPS (54 FR 38044) indicates that the value of 1E 4 was based on a survey which l
rusulted in a range of lifetime risk of EmmaWre mortalltv of 1E 1 to 1E-7. Thus. the point of ces, pron for assessing acceptability of the ta should be premature mortality. Fui.her, it should be noted that the NCRP and ICRP use cancer E b;;f as the basis for their decisions, if the risk coefficient for mortality is used, the calculated estimate of lifetime risk from 25 mromtyr is 3.8E-4 (based on a risk coefficient of SE-4 for morteilty versus 7E-4 for incidence), which approximates the 3 E 4 value that EPA concluded as essentially equivalent to the protective value 1E 4.
4 4.
EPA's use of BBCLs for groundwater results in inconenstant risk levels for cleanup NRC's approach of using an 'alkpothways' dose criterion means that the does to a memtrar of the put4c bm all pathways of exposure (air, water, food and direct radiation) would not be permitted to exceed 25 mre%r for unrestricted release. The groundwater p-E.si is induded in the 25 mromtyr dose critetton and licensees are specifically instructed to reduce the site-specific does to levels below 25 mromtyr when it is ALARA to do so. NRC has previously near===d its analyses of groundwater and the rationale for its a5 pathways standard in the FRN (62 FR 30074, July 21,1997) for its final rule, indicetmg there that I
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4 (1) en all. pathways dose cnterion provides a consistent risk-based standard, (2) maximum contaminent levels (MCL) are not set at consistent risk levels (and include some set above the NRC's dose enterien), and.(3) the costs of meeting certain MCLs may be extraordinarily excessive compared to the benefits obtained in certain cases. Further, it should also be noted that NRC analysis indicates that a decommiss6oned site meating the 25 mrem /yr all-pathways dose criterion is unlikely to result in a community water system delivering water to the tap with concentrations above the MCLs, because of both the process of dilution, decay, and trenoport in nature as the nudidas move through the aquifer cnd the process of water Wrection, treatment, and/or distribution.
!L EPA reference to NRC's alternate criteria la inaccurate The CERCLA guidance charactenzos the NRC rule as not protective in part because it indicates that NRC would allow a dose of up to 100 mrem /yr based on an exemption process.
This ignores the statement of :onsiderations in the FRN for NRC's cleanup rule (at 62 "R 39072) which described the nature of alternate criteria and the context of use of altamate criteria within tr a lCRP/NCRP radiation protectior 4amew >rk. It should be noted that EPA's draft cleanup rule (withdrawn by EPA from further consideration by OMB in December 1996) contained provisions that also allowed for exemptions from its all-pathways and separate groundwater standards. Specifically, the EPA's cleanup rule contained provisions to allow for instricted release, the uw of institutional controls with 5-year reviews, and the use of altemate concentration limits and Technical Impracticability Walvers when the amount of residual contemination exceeds the regulatory 16mits.
The FRN losuing NRC's final rule states that, "for the very large majority of NRC licensed sites' the 25 mremlyr dose criterion would be " appropriate and achievable,' but that the Commission was concemed about certain difficui sites presenting unique decommissioning problems. The FRN for NRC's proposed cleanup rule (59 FR 43217) indicated that it was anticipated that licensees of these facilities might seek exemptions from the criteria of the rule. However, the statement of considerations for the final rule indicate that, because these facilities would have to follow processes similar to those covered by the rule (e.g., evaluation of impacts and benefits, consioeradon of public Inputs, use of institubonal cortals, etc.), it was more appropriate to codify them in the regulations, rather than have thein seek an exemption from the' rule.
Liceneses of these tacilities would first have to evaluate release of their site for unrestricted use under 10 CFR 20.1402 of the rule or for restrided use under 10 CFR 20.1403. Only if those requirements could not be met would the Commisalon consider allowing sitomate critona. The FRN notes that the Commission expects that use of allemste criteria will be
- cormned to rare situebons' and " unusual sita specmc circumstances.'
in those rare comes where altamate entena were considered, the robonale for their use dortves ham the radiation protechon principles of NCRP and ICRP, namely the setting of a limit and reduction of the does below that limit based on a system of constraints and cost factors. NRC's cleenup rule would limit the dose for one of these unusual comes by rectuwing that the dose he kept below the 100 mrom/yr limit in 10 CFR Pa t 20 by a consideradon of artual sources at the specific site as well as by an opplication of ALARA principles.
Specifically, use of altomate atteria would only be allowed under 10 CFR 20.1404 following:
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5 (1) a detailed licensee analysis of all man-made soun:es in the vicinity of the she (10 CFR 20.1404(a)(1)); (2) a public discussion of the issues involved with the use of sNomate cnteria for that site (10 CFR 20.1404(a)(4)); and (3) EPA involvement in the process, and a specific approval by the Commission (10 CFR 20.1404 tb)).
Thus, tho rare occunence of use of altamate crRoria, the requirements for justifymg its use, and the detailed approval process required for its use, will result in altamate criteria being used only in those situations where it is appropriate and where it is protective under the rodiellon protodion principles of NCRP and ICRP.
8.
EPA is inconsistent noneeming whether or not redon is included in the CERCLA guidance In the Purpose section of the CERCLA guidance (page 1), EPA indicates that the policies described include redon as a contaminant of concem. However, potential ARARs in two cases discussed do not address the dose from radon, yet are described as accepteble.
In Attachment B (page 4) of the EPA CERCLA guidance, the 10 mromlyr standard for air emissions of radioactivity ( 40 CFR Part 61, Subpart I, now NRC's ' constraint" rule) is discussed as another standard that is consistent with a maximum allowable does level of 15 mromtyr. Since this air emission standard does not include dose from radon (see EPA CERCI.A guidance paragraph 2 on page 4 of Attachment B), it is not comparable to a dose limit of 15 mrerntyr that includes dose from all radionuchdes (that exceed M.v vund).
Also in Attachment B (page 5), the standards for cleanup of contaminated soils around uranium mills (!n 40 CFR Part 192) are described as consistent with the maximum allowa. ole dose standard of 15 mrem /yr. However, in their reassessment of doses from contaminated soil at the limits of 40 CFR Part 192, EPA does not include the does flem the radon omissions component of the residual radium. (Note that the dose and risk asessament performed for the final Environmental Impact Statement (EIS) for the cleanup standards (EPA,1982, Anal Environmental Impact Statement Ibr Remedd Ac6on Standards for Inacifve Uranium Processing Sites (40 CFR Part 192), Rep. EPA 520/4 82-0151) indicated that the lifetime risk from exposure to redca progeny at the standard was 2E 2.) in its reassessment, the EPA provuled results for the intiel calculations and for two ressessements The inittel calcu;ations were the same as described in a general document addressing dose calculations for many radionuclides and scenarios, referred to by EPA as the Technical Support Document (TBD) (EPA, September 1994, Rachselon Site Cloengp Reguiscons:
Technicef Sqpport Document Ibr the Deve60pment of RadionucNde Cleang Lewis lbr sod (Review Draft), Omoe of Air and Radetion), in the TBD, doses for radium 226 in soll were performed both with and without inclusion of the does from the associated radon. The TSD results reported in the reassessment document are the results which do not incfude the dose ham redon. This is inconsistent with the stated policy in the CERCLA guldence, which indiosted that redan was included. Based on the values in the TsD, the does wahout redon is estimated to be roughly orm. tenth the does if redon is induded, imlicating that (as expected) the dose fmm redon is the most important component of the total does from radium 22e m soil.
6 Allowing higher ooxentrations of radium In soil will, in tum, provide higher doses from radon.
Wthout this major component of the original analysis used to develop the standards in 40 CFR Part 192 (control of radon), higher doses to the public could result.
7.
CERCIA guidance reassesses doses from radon that results in significantly lower doses The EPA has reassessed the doses associated with concentratens of radium in soil at levels of the cleanup standards for uranium miles (concentrabons not to exceed background by more than 5 pCl/g in the top 15 cm of soil and 15 pCVO in any deeper 15 cm layer, in 40 CFR Part 192), and has indicated that the doses are less een 15 mrem /yr (page 5 of Attachment B and page 8 of Attachment B). The doses from such contamination levels appear to be significantly underestimated. The CERCLA guidance refers to another report (EPA, July 22, 1996. Reassessment of Radium and Thodum Sol Concentrations and Annual Dose Rates) for details of the dose estimates. NRC also raviewed this 1996 document and raises the following issues and concems:
- a. Dose assessment should address all potential site condit!w.s The EPA indicated in the 1996 document that the reassessment included ' generic model site characteristics, and standardized default exposure factors,* but then Indicated that EPA was "... interested in choosing modeling assumptions that are
' realistic
- or " reasonable," based on site-specific Information...." "ihls assessment should be applicable to all sites required to meet the 40 CFR Part 192 cleanup standards, but it has failed to do so (see comments below on changes to area and contaminated zone thickness parameters).
- b. The estimate of the comaminated area and layer th% ness are not rapresentattve in the TSD assessment, the contaminated area was assumed to be 10,000 m' and the contaminated layer was assumed to be 2 m thick, in tie 19g7 reassessment, these parameters were assumed to be "...a contammated zone eroa of 10Gni and thickness of 15 cm, as specified under 40 CFR Part ig2." The revised parameter values are not supported by the standards of 40 CFR Part 192, and do not appear to be representabve of potential sites regulated under the standards. Although the cleanup standards of 40 CFR Part 192 specsfy that the cisanup Imits appty to 100 m' areas and 15 cm thicknesses of soil, there le nothing to specify or even suggest that these values should be used in does assessments. For asseeming the does to a potential receptor (i.e., person) at a remediated alto, the actual area and depth of contamination should be used. Near uranium mit tailmgs altos, areas of windblown contammation can be as large as tens to hundreds of acres (tens of thousande to hundreds of thousands m'). Hence, the assumption of a contaminabad area of 100 n;'
is urwoeconably small. Further, regarding the contaminated zone thickness, the 40 CFR Part 192 standards clearty allow contaminated metanal thicker then 15 cm (the only thickness limitation is that the 5 pC4/g limit only applies to the top 15 cm of soil).
Thus, the EPA assumphon that the contaminated zone is only 15 cm thick rnay not be reasonable.
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7 The changes to the contaminated area and thickness appear to reduce the estimated dose (not including the radon dose) by a factor of about 4. and therefore are very important to the results of the reassessment.
- c. Changes to shielding Nctor and transfer factors were not available for NRC reYleW The reassessment also includes modification of the gamme exposure shielding factor wid the soHo-pient transfer factors fmm the values used in the TSD. Infonnation to suoport those changes is provided in a refsrence (Mauro J., SC4A, Reassessment of the Derived Concentrations Guide line LevelIbr Radium in Sol, memorandum dated January 16,1996, to B. Hus, EPA-ORIA) which was not available in timo for this review. Thus, thne modifications have not been evaluated by the NRC Mff.
8.
The CERCI A guidance lacks a baals for the assurnption that the 40 CFR Part 190 standard a 25/?5/26 mrom la equivalent to 10 mrom/yr i
The CERCLA gJ! dan:e includes reference to a doc; ment that explains how the 40 CFR Part 190 standard of 25/75/25 is equivalent to 10 mrem /yr and the 40 CFR Part 101 standard of 25/75 is equivalent to 15 mrem /yr. The comparisons of the EPA-proposed 15 mrom effective dose equivalent (EDE) limit and the previous standards, described in Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situatbns InvoMog Contaminated Land, April 1997, are technically inconsistent. The inconsistencies relate to the use of current dose methodologies to calculate acceptable soil concentrations under past standards. This overall calculational tr.ethod establishes bias in the resulting EDE and the calculated averagas to lower values. The comparison document itself shows that the relative consistency of the previous standards and 15 mrom EDE are highly radionuclide-specific and scenario-dep?ndent. This is in part because the previous standards were based on the assumption that all organ systems are equally radiosensitive, which based on today's understanding of radiobiology is an invalid sssumption. Therefore, comparisons with the previous standards cannot provide a sufficient technical basis for the 15 mrom proposed EPA standard, because the level of risk associated with the previous standards were case-specific, unlike the consistent level of risk used in the NRC standard.
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