ML20216H418
| ML20216H418 | |
| Person / Time | |
|---|---|
| Issue date: | 09/11/1997 |
| From: | Greeves J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Marcinowski F ENVIRONMENTAL PROTECTION AGENCY |
| References | |
| REF-WM-3 NUDOCS 9709160240 | |
| Download: ML20216H418 (24) | |
Text
_ _ _ _ _ _
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[gu k og UNITED STATES g-g NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 206(6 0001 September 11, 1997 Mr. Frank Marcinowski Radiation Protection Division Office of Radiation and Indoor Air (6602J)
United States Environmental Protection Agency 401 M Street, SW Washington, DC 20460
Dear Mr. Marcinowski:
On August 29,1997, in your facsimile forwarding the Environmental Protection Agency's (EPA's) clean up directive f r, and clarification of, the roles of Applicable or Relevant and Appropriate Requirements at superfund sites, you requested information about the remediation of the " nuclear reactor" at the Anne Arundel County /Curtis Bay Depot site in Anne Arundel County, MD. Specifically, you requested information on the dose levels to which the site was remediated.
Before addressing your questiori, it is important to note that this facility never was a nuclear reactor facility. The Curtis Bay Depot was, and continues to be, used by the Defense Logistics Agency (DLA) to store thorium nitrate, and other non-radioactive materials, as part of the National Defense Stockpile. A pxtion of the Curtis Bay Depot (the Anne Arundel County /Curtis Bay site) was excessed and sold to Anne Arundel County in 1978. Storage of radioactive l
material at Curtis Bay Depot facility is continuing in accordance with a radioactive materials license issued by the Nuclear Reg'intory Commission. The Anne Arundel County /Curtis Bay Depot site has been released for L nrestricted use, and was the subject of the letter sent to EPA on July 31,1997.
The Anne Arundel County /Curtis Bay Depot site was placed on the NRC's Site Decommissioning Management Plan (SDMP) list of sites in 1993 because the site contained unused buildings (9 dilapidated "tooden warehouses) and soil under, or adjacent to, the buildings with residual radioactive material levels in excess of the criteria in the NRC's SDMP Action Plan. As discussed in the SDMP Action Plan, the criteria for residual thorium in soil at facilities that are suitable for unrestricted use is 10 picoeuries per gram of soil. Because this site was placed on the SDMP, the criteria that were used for the decommissioning of the site were those outlined in the Plan and, as such, the NRC staff did not perform an estimate of the hypothetical doses to individuals at the site as part of the decommissioning. However, remedial activities by DLA have resulted in residual thorium levels in the soil et the facility, attributed to licensed activities, that are significantly below the NRC's criteria for thorium in soil. In fact, all but 5 soil samples, out of over 1000 soil samples collected to support the decommissioning of qg the site, exhibited less than 5 pCi/g of thorium. The maximum concentration of thorium found in these 5 samples was 6.6 pCilg of thorium.
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s F, Maroinowski 2-I hope this addresses your questions. If you have any further questions, or require additional information about the radiological status of the site please contact me t (301) 415 7437.
a Sincerely,
/ John T. Greeves, Director V
Division of Waste Management Office of Nuclear Material Safety and Safeguards l
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F. Marcinowski 2-September 11, 1997 I hope this addresses your questions. If you have any further questions, or require additional information about the radiological status of the site, please contact me at (301) 415-7437.
Sincerely,
[0riginal signed by]
John T. Greeves, Director Division of Waste Management Office of Nuclear Material Safety
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Oh/29/97 13:44 O202 233 9629 ORI A Rl'D 2 001
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United States Environmental Protection Agency
- Q n,'
Ofice ofRadiation and Indoor Air (6602])
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Radiation Protection Division
- Q /'/ jy 401 M Street, S.W.
i Washington, D.C. 20460 l
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1 L paoTE@
l PAGES TO FOLLOW:
28 TO:
John Greeves/ Margaret Federline TELEPIIONE:
(301) 415-6708 FAX NUMBER:
(301) 415 5397 l
l FROM:
Frank Marcinowski MAIL CODE:
6602J TELEP11ONE:
(202) 233 9437 FAX NUMBER:
(202) 233 9629 Attached is a list of current EPA computer models which is one of the follow-up items from our August 15* meetmg.
Also attached are two other it,s of which you she ul? be aware: 1) Is the recent radiation site dean-up directive for superfund sites; and 2) Clarification of the role of ARARs at superfund sites.
In addition, the NRC sent a letter to the Agency on 7/31/97 informing us that a nuclear reactor at the Curtis Bay Depot Site in Anne Arundel County, MD has been decommissioned. Do you have information regarding the dose levels to which that site was cleaned? I would appreciate any information you could share on that site.
Please give me a call if you have any questions regarding the attached documents.
G
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UNITED STATES ENVIRONMENTAL PROTECTION AOENCY WASHINGTON. D.C. 20460
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AUG 2 2 sg7 OSWER No.9200A 18 MutORANDUM
SUBJECT:
Establishment.of Cleanup Levels for CERCLA Sites with Radioactive Contaminatior
{y' bf FROM:
Stephen D. Luftig, Director
/
Office of Emergency and Remedial Response Larry Weinstock, Acting Director fq, Office of Radiation and Indoor Air s
TO:
Addressees PURPOSE This memorandum presents clarifying guidance for establishing protective cleanup levels' for radioactive contamination at Comprehertsive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) sites. The policies stated in this memorandum are inclusive of all radioacuve contaminants of concern at a site includws c.6n.' The directne is.'.mitei to providing guidance regarding the protection of human health and does not address levels necessary to protect ecological receptors.
'This directive provides guidance on cleanup levels expressed as a ruk, exposure, or dose level and not as a soil concentration level, The concentration level for vanous media such as soil, that corresponds to a given risk level should be determined on a site-specific basis, based on factors such as the assumed land use and the physical characteristics (e.g.,
important surface features, soils, geology, hydro geology, meteorology, and ecology) at the site. This guidance does not alter the National Oil ano Hazardous Substances Pollution Contingency Plan (NCP) expectauon.s regarding treatment of priticipal threat waste and the use of containment and institutional controls for low level threas waste.
2 Since redon is not covered in some Federal radiabon regulations it is important to note that the cleanup guidance c!anfications in this rnemorandum include radon. Attachment A is a listing of standards for radionuclides (including radon) that may be applicable or relevant and appropriate requirements (ARARs) for Superfund sites.
R, - '--it
%ee man sov4.enea arm on paper tr.u coetana at w ses recyoea 0C**
This document provides guidance to EPA staff. It also provides guidance to the public and to the regulated community on how EPA intends that the Natmnal Oil and 1
llazardous Substances Pollution Contmgency Plan (NCP) be implemented. The j
guidance is designed to describe EPA's national policy on these issues. The document does not, however, substitute for EPA's statutes or regulations, nor is it a regulation itself. Thus,it cannot impose legally binding requirements on EPA, States or the regulated community, and may not apply to a particular situation based upon the circumstances. EPA may change tius guidance in the future, as appropriate.
MCKGROUND All remedial actions at CERCLA sites must be protective of human health and the environment and comply with Applicable or Relevant and Appropriate Requirements (ARARs) unless a waiver is justified. Cleanup levels for response actions under CERCLA are develyd based on site specific tisk assessments ARARs, and/or to be consideted matenal'(TBCs).
A listmg it attached of radiation standards that are hkely to be used as ARARs to establish cleanup levels or to conduct remedial actions. Cleanup standards have been under development by EPA under the Atomic Energy Act (AEA) and will be ARARs under certain circumstances ifissued.
ARARs are often the determimng factor in establishing cleanup levels at CERCLA sites. However, where ARARs are not available or are not sufficiently protective, EPA generally sets site specific remediation levels for; l) carcinogens at a level that represents an excess upper bound lifetime cancer risk to an indisidual of 4
between 104 to 10 ; and for 2) non-carcinogens such that the cumulative risks from exposure will not result in adverse effects to human populations (including sensitive sub-populations) that may be exposed during a lifetime or part of a lifetime, incorporating an adequate margin of safety. (See 40 CFR 300.430(e)(2)(i)(A)(2).)
Since all radionuclides are carcinogens, this guidance addresses carcinogenic risk. If
.un-carcinogei risks a a med by spdfic raiianuclides, those risks should be taken mto account in establishing cleanup levels or suitable remedial actions. "the site-specific level of cleanup is determined using the nine criteria speci6ed in Section 300.430(c)(9)(iii) of the NCP.
ho-be-considered material (TBCs) are non promulgued advisones or guidance issued by Federal or State governmenu that are not legally bindmg and do not have the status of potential ARARs However, TBCs will be considered along with ARARs as part of the site ruk assessment and may be used in determmmg the necessary level of
. cleanup for protection of health and the environment.
2 -
i
f, NRC's Radiological Criteria for License Terminatio u gated :
1997). We expect that NRC's implementation of the rule for Licens T
, u y 21, (decommissioning ruje) will result in cleanups within the Sup f d e ermination vast majonty of NRC sites. Ilowever, EPA has determined that th d er un nsk range at the established in this rule as promulgated generally will notprovide a prot e ose limits an allowable cleanup level of 25 millirem per year ective basis for e
rule set increased lifetime nsk) as the prunary standard with exemptions all mately 5 x 10" risk) Accordingly, while the NRC rule standard mu owing dose limits of et me it is applicable or relevant and appropriate, cleanups at thes s tes where be more stringent than required by the NRC dose hmits in order toe sites will ty and NCP requirement to be protective.5 meet the CERCLA risk range (in general, cleanup levels exceeding 15 millirem per year CERCLA and generally should not be used to establi which equates to c ve under e e s.
radiation, together with the possibility of confusion as to e s or Agency regulations and guidance as ARARs or TBCs may cau s of other Federal cleanup levels deemed protective under CERCLA. Until a protectiv se uncertainty as to the CERCLA cleanup levels for radiation. radiation cleanup rule is avai e comprehensive position on OBJECTIVE I
range for all carcinogens established in the NCP wh e risk not sufficiently protective. This is to say, such cleanups should generally a aa e or are 1 vels in the 10d risks and determining PRGs at CERCLA sites no ma ter the eve risk ss ng cancer ontamination.'
'See leude, Carol Browner Adminir,trator, EPA, to Shirley Jackson Chairma February 7,1997.
n, Nuclem ReEutatory Commasion, 5
See scachment B for a detailed ducussion of the basts for the con:lusi adequately protec:ive.
on that the dose limits in the NRC rule are not
'U.S. EPA, " Risk Assessment Guidance for Superfund Volume 1 Huma H Final, EPA!/54o/189/002. December 1989. U.S. EPA " Risk Asses m ealth Evalumuou Manual (Part A) Interim n
Health Evaluanon Manual (Part B, Development of Risk based Prcli i s ent Guidance for Superfund: Volume ! - Human Demnber 1991.
m nary Remediation Goals". EPA /540/R 92/003, 3 _
Cancer risks for radionuclides should generally be estimated using the slope factor approach identified in this methodology. Slope factors were developed by EPA for more than 300 radionuclides in the Health Effects Assessment Summary Tables (ILEAST).' Cleanup levels for radioactive contamination at CERCLA sites should be established as they would for any chemical that poses an unacceptable risk and the risks should be characterized in standard Agency risk language consistent with CERCLA guidance.
Historically, radiation exposure and cleanup levels have often been expressed in units unique to radiation (e.g., millirem or picoCuries), it is important for the purposes of clarity that a consistent set of existing risk-based units (i.e., # x10') for cleanups generally be used. This will also allow for ease and clanty of presenting cumulative risk for all contamir.:nts, an objective consistent with EPA's policy on risk characterization.:
Cancer risk from both radiological and non radiological contaminants should be summed to provide risk estimates for persons exposed to both types of carcinogenic contaminants. Although these nsks initially may be tabulated separately, risk estimates contained in proposed and final site decision documents (e.g., proposed plans, Record of Decisions (RODS), Action Memos, ROD Amendments, Explanation of Significant Differences (ESDs)) should be summed to provide an estimate of the combined risk to individuals presented by all carcinogenic contammants.
IMPLEMENTATION The approach in this guidance should be considered at current and future CERCLA sites for which response decisions have not been made.
Overall Exposure Limit:
Cleanup should generally achieve a level of risk within the 104 to 104 carcinogenic ik range based < i N easonable m utimum exposure for an individual.
t The cleanup levels to be specified include exposures from all potential pathways, and through all media (e.g., soil, ground water, surface water, sediment, air, structures, 7U.S. EPA," Health Effects Assessment Summary Tables FY 1995 Annual," EPA /54o/R 95/036, May 1995; and U.S.
EPA," Health Effects Assessment Summary Tables FY-1995 Supplement," EPA /54o/R-95/142, Nov.1995.
"For further discussion of EPA's policy, see memorandum from EPA Administrator Carol Browner entitled:" EPA Risk Characterization Program." March 21,1995. l
biota). As noted in previous policy, "the upper boundary of the risk range is not a discr'ete line at 1 x 10*, although EPA generally uses 1 x 104 in making tisk management decisions. A specific risk estimale around 104 may be considered acceptable ifjustified based on site specific conditions"'
If a dose assessment is conducted at the site" then 15 millirem per year (mrem /yr) effective dose equivalent (EDE) should generally be the maximum dose limit for humans. This level equates to approximately 3 x 10" increased lifetime risk and is consistent with levels generally considered protective m other governmental actions, particularly regulations and guidance developed by EPA in other radiation control programs."
Background Contamination:
Back round radiatiou levels will generally be determined as background levels 6
are determined for other contammants, on a site specific basis. In some cases, the same constituents are found in on site samples as well as in background samples. The levels of each constituent are compared to background to determine its impact, if any, on site-related activities. Background is generally measured only for those radionuclides that i
are contammants of concern and is compared on a contaminant specific basis to cleanup level. For example, background levels for radium 226 and radon 222 would generally not be evaluated at a site if those radionuclides were not site related contaminants.
' Memo from Asstatant Administrator Don Clay to the R i
Remedy Selecuon Decisions'" OSWER Direcuve 9355.0 30, Apnl 22,1991.e6 ons;" Role of the Baseline Risk A
" Cleanup les :h not bwd on ARARs.. 09"
- etr tssed as e raillitem.
sk, altheuoh 6cvels may at the same 11 be expressed "Funber discussion and analysis of the basis for this recommendation is contained in the mate the AEA standard under development by EPA, which is available at the following address:
Room M1500, Air Docket No. A 93 27, Washington D C. 20460. 'the maaarial is alm available via coa.p through the Clannup Regulation Electronic Butieun Board (s00 700 7837 outside the Washington area and 7 locally), or on-line through the Radiation Site Cleenup Regulasion HomePase (httpJtwww.epassovira Cleanup levels based on some olde< ARARs that use a 2505/25 mrumtyr standard (i.e.,25 mremtyt mrem /yr to the thyroid, and 25 mrem /yr in any other critacal organ) may appear to pennd gresact risk than tho ARARs based on a25n5 mesm/yr standard used as an ARAR (i e.,2 m
critical organ) would on average correspond to those cleanups based on 15 mrum/yr EDE. (See also "
Critical Organ and EDE Radiation Dose Rate Limits for Situanons involving Contaminated Land;" Office of R and Indoor Air; April 1997.) See also Attachment B.
-5
4 6
In certain situations background levels of a site related contaminant may equal or exceed PRGs established for a site. In these situations background and site related levels of radiation will be addressed as they are for other contammants at CERCLA sites."
Land (1sc and Institutional Controls:
The concentration levels for various media that correspond to the acceptable risk level established for cleanup will depend in part on land use at the site. Land uses that will be available following completion of a response action are determined as part of the remedy selection process considering the reasonably anticipated land use or uses along with other factors." Institutional controls (ICs) generally should be included as a component of cleanup altematives that would require restncted land use in order to ensure the response will be protective over time. The institutional controls should prevent an unanticipated chang-in land use that could result in unacceptable exposures to residual contamination, or at a minimum, alert future users to the residual risks and monitor for any changes in use.
l Future Changes in Land Use:
Where waste is left on site at levels that would requue limited use and restricted exposure to ensure protectiveness, EPA will conduct reviews at least once every five years to monitor the site for any changes including changes in land use. Such reviews should analyze the implementation and effectiveness of any ICs with the same degree of care as other parts of the remedy. Should land use change in spite ofland use "For further informauon segnadmg EPA's approach for addressing background at CERCLA sites see: National Oil
.d llaardous SMtances Pollution Contingenev Pim 55 FR 8717 8718, March 8,1990; U.S. EPA " Guidance on nemedial Actio, for Contamu.. t Gmund Water at Syerfund Snes," EPA /s43 G-ss!oo3, December 19F', 3 4-9, U.S. i'A " Soil Senerung Guidance: User's Gmde," EP A/540/R 96M1s. Apnl 1996, pg. s; and U.S. EPA *tCsk Assessment Guidance for Superfund Volume I fluman licalth Evaluation Manual (Part A)," EPA /540/l 89/02, Decernber 1989, pp. 4-5 to 4-10 and 5 18 to 519. It should be noted that certain ARARs specifically address how to factor background into cleanup levels. For example, some radiation ARAR levels are catablished as meremer ts above backgrotmd concentrations. (See atsached chart for a hstmg of radiation standards that are likely to be used as ARARs.)
la these circumstances, rasher then fotlow the general guidance cited above, background should be addressed in the manner prescribed by the ARAR ARARs, such as 40 CFR 192, are available to establish cleanup levels for those naturally occurring radionuclides that pose the most ruk (such as radium-226 or norium in soil, and indoor radon) when those radionuclides are site related contaminants.
tn developing Land use assumptions, decision makers should consult the guidance provided in the memorandum U
from Elliott Laws A.A., OSWER aantled " Land Use in the CERC1,A Remedy Selectian Process"(OSWER Directive No. 9355.7 04), May 25,1995.
6
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restnetions, it will be necessary to evaluate the implications of that change for the selected remedy, and whether the remedy remains protective (e.g., a greater volume of soil may need to be removed or rnanaged to achieve an acceptable level of risk for a less restrictive land use).
Ground Water Levels:
Consistent with CERCLA and the NCP, response actions for contaminated ground water at radiation sites must attain (or waive as appropriate) the Maximum Contaminant Levels (MCLs) or non-zero Maximum Contaminant Level Goals
. (MCLGs) established under the Safe Drmking Water Act, where the MCLs or MCLGs are relevant and appropriate for the site. This will typically be the case where ground waters are a current or potential source of drinkmg water." The ARARs should generally be attamed throughout the plume (i.e., in the aquifer).
{
Modeling Aasessaient of Future Exposures:
Risk levels, ground water cleanup, and dose limits should be predicted using appropriate models to examine the estimated future threats posed by residual radioactive material following the completion of the response action." The modeling assessment should: (1) assume that the current physical characteristics (e.g., important surface features, soils, geology, hydrogeology, meteorology, and ecology).will continue to exist at the site; (2) take into account for each particular radionuclide that is a site-related contaminant, the following factors:
radioactive decay and the ingrowth of radioactive decay products when asseasing risk levels;
- the year of peak concentration in the ground water when assessing protection (e.g., remediating previous contamination and preventing future contamination)
- of ground water, andt the year of peak dose when assessing dose limits; and, (3) model the expected movement of radioactive material at the site both within media (i.e., soil, ground water, surface uter, sediment. stractures, air, biota) and to other -
media.'
"la malung decisions on ground wuser protection, decision makers should consult the guidance provided in
Presunpuw Response Strassy ad Ex Situ Trumanent Technologies for Conta:niassed Ground Waser at CERCLA Shes" (OSWER Directive No. 9355.7-04) October 1996.
"For further information regarding the basis for this recommendation, see U.S. EPA," Risk Assessment Guidance for Superfund Volume 1 Human Health Evaluanon Manual (Part A) Interim Final," EPA //540/t 49/002, December t989, pp.
10-22 and 10 24.
7
EURIIER INFORMATION The subject matter specialists for this directive are Jeffrey Phillips of OERR and John Karhnak of ORIA. General questions about this directive, should be directed to 1 800-424 9346.
Attachments Addressees National Superfund Policy Managers Superfund Branch Chiefs (Regions 1-X)
Superfund Branch Chiefs, Omcc of Regional Counsel (Regions I-X)
Radiation Program Managers (Regions I, IV, V, VI, VII, X) l Radiation Branch Chief (Region II)
L Residential Domain Section Chief (Region III) i Radiation and Indoor Air Program Branch Chief (Region Vill)
Radiation and Indoor Office Director (Region DO Federal Facilities Leadership Council OERR Center Directors CC:
Jim Woolford, FFRRO Elimbeth Cotsworth, OSW Craig Hooks, FFEO Barry Breen, OSRE Joanna Gibson, HOSC/OERR Earl Salo,- OGC 8--
Attachment A:
Likely Federal Radiation Applicable or Relevant and Appropriate Requirements (ARARs)
I he attached drafi table of Federal standards is a listing of Federal rad:ation regulations that may be " Applicable or Relevant aml Appmpriate Requirements"(AR/ Rs) for Supesfund response actions. ~1 his list is not a comprehensive list of Federal radiation i
standards. It must also be cautirned that the selection of ARAlb is site-specific and those site-specific determinations may ditTer f ram l
the attached analysis for some of the following ARARs Likely Ft dcral Radiation (AFA, UMTRCA, CAA, CWA, SDWA) ARARs When is standard When.is standard Applicable potentially a Relevant Standard Citat. ion (Conduct /Operat. ion and Appropriate or Level of Requiremnt Clea nup')
Maximum contaminant levels (MCLs). Drinkmg 40 CFR 141 Rarely At the tap where Where ground or surface water water regulations designed to protect human water will be provided is considered a potential or health from the potential adverse effects of directly to 25 or more current source of drinking drinking water contaminants.
people or will be supplied water to I 5 or more service connections.
Concentration limits for liquid cDluents from 40 CFR 440 Very Unlikely: Applies to Discharges to surface waters facilities that extract and process uranium, Subpart C surface wakw discharges of some kinds of radioactive radium, and vanadium ores.
from certain kind of waste.
mines and mills 1
Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs i
When is standard Standard AppItcable When is standard Citation (ConducuOperation potentially a Relevant or Level of and Appropriate j
Cleanup.)
Requirernent 1:cdeial Water Quality criteria - WQC) and Water Qaahty Dacharge f om a
)
State Water Quality Standards i WQS)
Criteria; Repmt CERCLA ute to surface surface water. (l.C) j Restoration of contaminated
('nieria/ standards for protection of aquatic lite of the National water (C/0) aind/or hurnan health depending upon the Technical designated water use.
Advisory Cornmittee to the Secretary of the Interior, April 1 1968 Concentration limits for cleanup of radiurn-226, 40 CFR i
i radium-228, and thorium in soil at inactive Never: Standeds are Sites with soil contaminated 192.12(4),
applicable only to with rad:um-226. radium-228 uranium processing sites designate d for reinedial 192.32(b)(.2), and UMTRCA sites that are and/or thorsurn action '
192.41 exempt from CERCI A 1
Tor funher information, set OSWER directive entitled "Use of Soil Cleanup Criteria in Su Remediation Goals for CERCLA sites."
e
.,. :. i Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs When is standard When is standard Applicable potentially a Relevant Standard Citat. ion (Conduct / Operation and Appropriate 1
or Level of Requirement l
Cleanup,)
l Combined exposure limits for cl anup of radon 40 CFR Never: Standards are Sites with radioactive decay pmdocts in buildings at in. tive uranium 192.12(b)(1) and applicabie only to contamination that is currently, piecessing sites designated for remedial action 192A1(b)
('M1 RCA sites that are or may potentially, result in exempt fmm 7ERCLA
. radon that is caused by site related cortamination migrating fmm the soilinto buildings Contentration limits for cleanup of gamma 40 CFR Never: Standaris are Sites with radioactar radiation in buildings at inactivt uranium 192.12(b)(2) applicable only to contamination th.n is current:y, processing sites designated for remedial action UMTRCA sites that are or may potentially, emit exempt from CERCLA gamma radiation Design requirements for remedial actions that 40 CFR 192.02 Never: Standards are Sites with radan-220 or radon-f involve disposal for controlling combined applicable only to 222 as con:aminants which releases of radon-220 and radon-222 to the UMTRCA si:es that are will be disposed of on-site.
atmosphere at inactive uranium processing sites exempt from CERCLA designated for remedial action W _ _ _ _ _ _ _ _ _ _ _ _ _ _
Likely Federal Radiation (AEA, UMTRCA, CAA, CWA, SDWA) ARARs When is standard
- When.is standard Appl.icable potentially a Relevant Standard Citation (Conduct / Operation and Appropr. te ia or level of Requ.irement Cleanup,)
Performance objectives for the md di.spoul of 10 CFR 6141 thrhAely Existing Previcusly closed sites I
low lesel nidioactive waste (I.1 /).
!icensed f 1,W disposal containing 11W if the waste 3 tes at the time oflicense will be permanently left on renewat (I.C) site.
l
[hshkelyIhat Ihis would occur.
National Emission Standards for llanstdous Air 40 CFR 61 Airborne emissions Cleanup of other sites with Polictants (NF.SilAPs) under the Clean Air Act, Subparts 11 and I daring the cleanup of radioactise contamination Federal Facilities and that apply to radionuclides _
licensed NRC facilities.
(CO)
Radiological criteria for license termination.
10 CFR 20 Existing licensed sites at Previously closed sites Subpart E the time oflicense termination. (LC)
- 1. Conduct / operation (C/0) refers to those standards which are typically ARARs for the conduct or operation of the remedial Level of Cleanup (ljC) refers to those standards which are ty pically ARARs for determining the final level of ticanup...
)
1, August 20,1997 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)
Introduction The Nuclear Regulatory Commission ("NRC") has finalized a rule titled
"_ Radiological Criteria for License Termination"(see 62 FR 39058, July 21,1997) EPA has determined that the dose limits established in this rule generally will not provide a l
protective basis for establishing preliminary rernediation goals ("PRGs")under the Comprehensive Emironmental Response. Compensation and Liability Act
(" CERCLA") ' The NRC rule sets an allowable cleanup lesel of 25 millirem per year I
effective dose equivalent (EDE)(equivalent to approximately $ x lod lifetime cancer risk) as the primary standard with exemptions allowing cleanup levels of up to 100 millirem per year (mremlyr) EDE (equivalent to approximately 2 x 104 lifetime risk).2 While the NRC standards must be met (or waived) at sites where it is applicable or -
relevant and appropriate, cleanups at these sites will typically have to be more protective than required by the NRC rule dose limits in_ order to meet the requirement to be protective established in CERCLA and the 1990 revisions to the National Oil and Hazardous Substances Pollution Contingency Plan ("NCP").3 Protectiveness for carcinogens under CERCLA is generally determined with reference to a cancer risk range of 10" to 104 deemed acceptable by EPA. Consistent with this ri:k c=;;e, EPA h9 consider, a car.er -isk from radiation in a number of difTerent contexts, and has sensiitently concluded that levels of 15 mrem /yr EDE (which
'See letter, Carol Browner. Admininrator, EPA, to Shirley Jackson, Chairman, Nuclear Regulatory Commission
_ February 7,1997.
3 Throughout this analysis nsk cstmares for dose lev cls wtrs denved using a risk assessment methodology consistent with CERCl,A guidance for assessing risks.
Similarly, gwdance that provides for radiahon cleanups otaside the risk range is generally not protective and should not be ssed to establish preliminary emediation goals..,s m__.
___D
v Augu.st 20.1997 equate to approximately a 3 x 10d cancer risk) or less are protectn e and achievable '
EPA has explicitly rejected levels abme 15 mrem'yr EDE as being not sufficiently protective.
The dose lesels established in the NRC Decommissioning rule, however, are not based on this nsk range or on an analysis of other achievable protective cleanup levels used for radiation and other carcinogenic standards. Rather, they are based on a different framework for risk management recommended by the International Commission on Radiation Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP). NRC's application of this framework starts with the premise t. hat exposure to radiation from all man made sources, excluding medical and natural background exposures, of up to 100 mrem /yr., which equates to a cancer nsk of 2 x 104 is acceptable. Based on tuat premise, it coxludes that exposure from decommissio ned facilities of 25 mrem <yr, which equates to a cancer nsk of approx.imately 5 x 10", is acceptable, and allows the granting of exceptions tn certain instances permirtmg exposure up to the full dosage of 100 mremey r from these facilities. EPA has carefully reviewed the basis for the NRC dose lesels and does not believe they are generally protectise within the framework of CERCLA and the NCP. Simply put, NRC has provided, and EPA is aware of, no technical, policy, or legal rationale for treating radiation nsks differently from other nsks addressed under CERCLA and for allowing radiation risks so far beyond the bounds of the CERCLA risk range.
- lt should be noted the is mrem /yr is a dose level, not a media remediation level. Accordingly, this achieved at CERCLA sites through appropnate site specstic combinations of active remediation and land-use rest ensure no une:eptable exposures.
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9 August 20.1997 1.
Rat!onale for 15 mremlyr as Minimally Acceptable Dose Limit To determine an acceptable residual lesel of nsk from residual radioactive materials followmg a response action that would be protective of human health, EPA exarmned the precedents established by EPA for acceptable exposures to radiation in regulations and site-specific cleanup decisions in light of the CERCLA risk range for carcinogens. EPA's conclusion is that to be considered protective under CERCLA, remedial actions should generally attain dose levels of no more than 15 mrenVyr EDE for those sites at which a dose assessment is conducted. This dose level corresponds to an excess lifetime cancer risk of approximately 3 x 10" 1,1 The CERCLA risk range Under CERCLA, all remedies are required to attam cleanup levels that "at a minimum
, assure protection of human health and the environment." CERCLA Q121(d)(1). The NCP provides that, for carcinogens, prehminary remediation goals should generally be set at levels that represent an upper-bound hfetime cancer nsk to an individual of between 10d and 104 40 CFR s 300.430(e)(2)(1)(A)(1). This regulatory level was set based on EPA's conclusion that the CERCLA protectiveness mandate is complied with "when the amount of exposure is reduced so that the risk posed by contaminants is very small, i.e., at an acceptable level. EPA's risk range of 104 to 10*
represents EPA's opinion on what are generally acceptable levels." 55 Fed. Reg. at 8716 (March 8,1990). EPA's adoption of this risk range was sustained in judicial review of the NCP. State of Ohio v. EPA,997 F.2d 1520,1533 (D.C. Cir.1993).
Under appropriate circumstances, nsks of greater than 1 x 10dmay be acceptable.
CERCLA guidance states that "the upper boundary of the risk range is not a discrete line at ! x 10d, although EPA generally uses I s lod in making nsk management decisions.
A specific risk estimate around 104 may be considered acceptable ifjustified based on site-specific conaions7 Cther EPA regulatory programs have developed a similar spproach to determining acceptable levels of cancer risk. For example, in a Clean Air Act rulemaking establishing NESHAPs for NRC licensees, Department of Energy facilities, and many other kinds of sites, EPA concluded that a risk level of"3 x 10' is essentially equivalent to the presumptively safe level of 1 x 10"," 54 Fed. Reg. at 51677 and 51682 (December 15,1989). EPA explicitly rejected a risk level of 5.7 x 10d being equivalent to the presumptively safe level of I x 10' (in the case of elemental as not phosphorus plants) in this rulemaking. 54 Fed. Reg, at 51670.
- s. Role of the Bascime Risk Assessment m Superfund Remedy Se'mion Decisionv' from EPA A R. Clay, April 22,1991.
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August 20.1997 1.2 Prior rulemaking decisions EPA has examined the pru.?ctiveness of various radiation les els on a number of occasions in each case. EPA's determination of what constitutes an adequarc lesel of protection was reached in a manner consutent with EPA's regulation of other carcinogens. The conclusions from these efforts support the determination that 15 mrem'yr EDE should generally be the maximum dose level allowed at CERCLA sites.
For example, EPA's Environtnental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High Level and Transuranic Radioactive Wastes ("High-Level Waste Rule," 40 CFR Part 191) sets a dose limit of 15 mrem /yr EDE for all pathways.
In addition, EPA set an effective dose equivalent of 10 mrem'yr EDE (excluding radon-222) for air emissions of racionuclides from federal facilities, NRC licensees, and uranium fuel cycle facilities under the National Emissions Standards for Hazardous Air Pollutants (NESHAP,40 CFR Part 61). This lower limit included all air pathways, but excluded re' eases to surface and ground waters.
1 Not all EPA rules apply the cunent dose rnethodology of effe<.tise dose equivalent (EDE). A dose limit of 15 mrem'yr EDE is also consistent with the dose levels allowed under older multi media standards that were based on the critical organ approach to dose limitation. Critical organ standards developed by EPA and NRC consist of a combination of whole body and entical organ dose limits. Three of these critical organ standards (EPA's uranium fuel cycle rule,40 CFR 190.10(a), developed for NRC licensees; NRC's low level waste rule,10 CFR 61.41; and EPA's management and storage of high level waste by NRC and agreement states rule,40 CFR 191.03(a)), referred to here as
'25/75/25 mrem /yr' dose limits, are expressed as 25 mrem /yr to the whole body, 75 mremlyr to the thyroid, and 25 mrem /yr to any critical organ other than the thyroid. One standard (EPA's management and storage of high level waste by DOE rule,40 CFR 191.03(b)), referred to here as a "25/75 mrem /yr" dose limit, is expressed as 25 mremlyr te the whole lx. iy and 75 mrer,. jr to any critical or.;2n (including the thyroid). To compare the dose level allowed under standards expressed in terms of EDE with the dose levels allowed under the critical organ approach to dose limitation, EPA has analyzed the estimated effective dose equivalent levels that would result if sites were cleaned up to the numerical dose limits used in these standards.' The analysis indicates that if sites were cleaned up under a 2505/25 mrem /yr dose limit, the residual contamination would correspond to approximately 10 mrem /yr EDE. For sites cleaned up under a 25/75 mrem /yr dose limit, the residual contamination would correspond to approximately 15
- Comparison of Critical Organ and EDE Radiation Dose Rate Limits for Situations involvmg Cantaminated Land" Office of Radiation and Indoor Air; April 1997.
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s August 20,1997 mrem /yr EDE. These lindings are similar to those mentioned in the preamb!c to the high.
level waste rule (40 CFR Part 191; December 20.1993; 58 FR 66402) In that rulemaking, EPA noted that the dose limit of 25 mretn'yr to the whole body or 75 mrcm/yr to any critical o gan. which was used in a previous high level waste rule (September 19,1985; 50 FR 38066) conesponds to the same level of risk as that associated with a 15 mremlyr EDE. A cleanup level of 15 mremlyr EDE is thus generally consistent with all of these other standards, although there are minor differences.
Finally, standards for the cleanup of certain radioactively contaminated sites have been issued under the Uranium Mill Tailings Radiation Control Act (UMTRCA), P.L.
'i 95-604. Those standards are codified at 40 CFR Part 192. Among other provisions, tne UMTRCA standards limit the co..;cntration of radium 226, radium-228, thorium 230 and thorium 232, within 15 centu.eters (cm) of the surface to no more than 5 picoCuries per gram (pCi/g) over background. They also limit the concentration of these radionuclides below the surface to no more than 15 pCi/g over background. Since these standards were developed for the specific conditions found at the mill sites to which they apply (for example, all mill sites are required by law to remain in federal control), correlating these concentrations to dose requaes a site-specific determination considering both the distribution and nature of contaminants at the site and the selected land usc. - Therefore, those standards are less relevant for determining if 15 mrem /yr EDE is consistent.
However, analysis indicates that the cleanup of UMTRCA sites is consistent with the minimally acceptable dose limit of 15 mrcm/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.'
1.3 Site-Specific Decisions EPA has examined the cleanup Jecisions made undct Superfund to address si.e contaminated with radioactive wastes. Many of these cleanup actions used the UMTRCA
' Reassessment ofRadhm and Thorrum Sou Comentration and AnnualDase Rates. Omce of Radiation and ind Air, July 22,1996.
'A level of 15 mnem/yt is also suppocod by EPA's draft Federal Radiation Protection Guidance for Exposure of the Gcricral Public (59 FR 664I4, Decemoct 23, t994). The draft guidance recommends that the maximum dose to individuals from specific sources or categories of sources be established as small fractions of a 100 mrem /yr upper bound on doses from all current and potential future sources combined, and cites the regulations that are discussed in Section 1.2 of this paper as appropriate implementation of this recommendation. All of the regulatory examples cited support the selection of cleanup levels at 15 mrorrvyt or less. However, because this guidance is in draft form and is subject to contmued review within EPA prior to finalization. it should not be used as a basis for estabhshing acceptable cleanup levels.
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t August 20,1997 cleanup standard (40 CFR Part 192) as an ARAR. Some of the sites used State regulations as ARARs For a number of major DOE cleanup actions such as those at the Hanford reservation and Rocky Flats, a 15 mrem'yr EDE cleanup level has been decided upon or proposed. In other cases of CERCLA radiation cleanup actions that are not based on ARARs, cleanup le' els between 1 x 10 and I x 10' have been selected (Bomark, NJ; Fernald, OH; Charleston Naval Shipyard, SC; and Mare Islar.d Naval Shipyard, CA).
Overall EPA finds that a !$ rnrem/yr EDE level (with a risk of 3 x 10")is at the upper end of remediation levels that have generally been selected at radioactively contaminated CERCLA sites.
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August 20,1997 2,0 Dose Limits in NRC's Rule are not Protective EPA reviewed the dose hmits that tre contained in SRC's Radiological Cntena for 1.icense Termination (see 62 FR 39058. July 21.1997) The NRC rule allows a cleanup level of 25 mrerwyr EDE (equivalent to approximately 5 x 10" lifetime risk) with exemptions allowing cleanup levels of up to 100 mrerwyr EDE (equivalent to approximately 2 x 104 lifetime risk). These limits 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. EPA has no technical or policy basis to conclude that these levels are protective under CERCLA.
The risk lesels corresponding to the 25 to 100 mrem /yr EDE range allowed by the NRC rule (5 x 10"to 2 x 104) are unacceptably high relatise to 1 x 10', which is the risk level generally used as the upper boundary of the CERCLA risk range for making risk management decisions at CERCLA sites. This determination is consistent with EPA's explicit rejection of a risk lesel of 5.7 x 10' for elemental phosphorus plants in the preamble for a NESHAP rulemakmg (54 FR 51670). In the same preamble, EPA stated t
that a risk level of"3 x 10" is essentially eqtusalent to the presumptively safe level of 1 x 10d"(54 FR 51677). It was dunng this same NESHAP rulemaking that NCRP first recommended to EPA its regulatory scheme (a dose limit of 25 mrem /yr EDE for a single source that if met would not require analyzing other sources, otherwise a dose lanit of 100 mremlyr EDE from all sources combined) that NRC cites as a source for the regulatory approach taken in its decommissioning rule.' EPA rejected NCRP's recommended regulatory scheme, and promulgated dose limits of no more than 10 mremlyr EDE in its NESHAP rulemaking for radionuclides, while concluding that
" individual dose levels greater than 10 mremly ede are inconsistent with the requirements of section 112" of the Clean Air Act. 54 Fed. Reg at 51686.
The documentation and analysis supporting the NRC rule dose levels provide na basis for such a significam hpan. e from the CERCLA risk range. Indeed, as discussed tbove, EPA's past analyses and expenence have demonstrated that exposures of 15 mremlyr EDE or less are attainable and that such a departure is unwarranted. A dose limit of 25 mrern/yr EDE represents almost a doubling of the allowable risk from previous radiation rulemakings; the risk represented by a dose limit of 100 mrem /yr EDE is seven times as high as previously allowed. As note in Section 1.2, a dose limit of 25 mremlyr effective dose equivalent is inconsistent with the dose levels allowed under older
Control of Air Emissions of Radionuclides" NCRP Position Statement No. 6. The report cited by NRC. SCR No,116. merely refennees this previous NCRP position statement. '
August 20.199.7 standards using a previous dose methodology (multi media standards that were based on the critical organ approach to dosc limitatient if these older dose standards were to be applied to the c!canup of contanunated sites, the aserage dose level would correspond to approximately 10 or 15 mrem'>r EDE on ascrage
- Also. analy sis indicates that the cleanup of UMTRCA sites usir.g the 5 pCi<g and 15 pCi/g soil standards under 40 CFR 192 is consistent with an upper bound of 15 miem'yr EDE under a rural 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 cicanup standards are more stringent for all four radionuclides.
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- Companson of Cntacal Organ and EDE Radtation Dose Rate Lirmts for Situations involving Contaminated Land" OfUce of Radiation and Indoor Alt; April 1997.
'Reassenment ofRadwm and Thormm Sod Com entratiora and Annual Dose Rates. OtDec of Radiation and indoor Air, July 22,1996.
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