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8 NUCLTAR MEGULATORY COMMLSSIOh[_
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l MEMORANDUM FOR:
F. Gillespie, Director Program Management Policy Development and Analysis Staff, MRR
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r M. Knapp, Director j
Division of Low Level Waste Management-and Decomissioning, NMSS l
R. Cunningham, Director
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Division of Industrial & Medical j
- l' Nuclear Safety, NMSS F. Congel, Director Division of Radiation Protection and Emergency Preparedness, NRR FROM:
Bill M. Morris, Director Division of Regulatory Applications, RES
SUBJECT:
DE MINIMIS, BELOW REGULATORY CONCERN AND RESIDUAL RADIOACTIVITY RELEASE STANDARDS -- COMMISSION REQUESTED-REPORT /0PTIONS PAPER.
In the-staff requirements memorandum of November 24, 1987 (Enclosure 1), which responded to-SECY-87-186A, the Commission directed the staff to "... develop a proposed Commission policy statement that will identify a level of radiation risk below which government regulation becomes unwarranted." The Commission requested that a status report / options paper on the "de minimis or below regulatory concern question" be provided for Commission review by January 29, 1988. EDO subsequently assigned RES the task of preparing the paper in coordination with all affected offices.
Our preliminary discussiont kith NMSS and NRR staff indicate that regulatory implementation of the concepts of de minimis and below regulatory concern can have a significant impact on regulatory policy. The first step to be taken to achieve participation of all affected Offices is (1) to define de minimis, below regulatory concern and residual radioactivity terms and concepts, (2) to discusstherelationshipsbetweentheseconceptual" release"standardsand(3) to describe NRC staff initiatives with regard to the development of these concepts. Enclosure 2 represents a first draft attempt to address these subjects and also contains a proposed framework for consistant regulatory dose l imitations and policy options which could be presented to the Commission for their consideration.
I would appreciate your critical review of Enclosure 2.
My short-tenn plan is to convene a Divisional meeting the week of January 4. 1988 to discuss our
- thoughts on this draft paper with you. We would then use your coments to s
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O ' s * - facilities and (2) 40 CFR Part 61 which applies to 1.g y it, . -l, - airborne effluents from all licensees. Both of these Y o s' regulations impose dose limits whic eagnitudherea s ( small fraction of Federal guidance limits. Appendix I of \\ 10 CFR Part 50 also establishes annual whole body and g'h thyroid dose equivalent design objectives lower than the f EPA-established limits. 11/05/87 SMN ~ V. 4 { ' -r ~ v' } . ' ~ ~ ~ ~- ~ L*f -The Commissioner's, 4,,-~ ,' ~ ~_ a ~ ~ ~ i To date,-the EPA..NRC, DOE, 000, D0T, State,agensies and-l others ha've established and enforced standards applicable l ~ within' their mandated jurisdictions. There has been a tendency to develop specific standards on the basis of cost-risk reduction analysis that considers only the source under study. However, no coordinated action has been initiated to establish an acceptable level of collective risk for public exposure to multiple sources i of ionizing radiation or to allocate appropriate f fractions of this risk to each contributing source. ) L A Federal interagency committee has been formed under the L lead of the EPA to prepare new presidential guidance to l. , !c't e Federal agencies on protection of the public from all r .e sources of radiation subject to governmental control. An ' f,t ' g' objective of the guidance is to assure consistency l E throughout the nation in the control of these sources, which include facility effluents, radioactive wsste, transportation, decommissioned lands and structures, p 1 o ,p unrestricted release of materials and equipment, and radioactivity in consumer products, among others. L. The NRC staff is participating in these standards l the development activities with EPA on several levels: Federal interagency committee, the NRC> EPA Interface y- [ Council which is responsible for overall coordination between the two agencies, and direct staff contacts, ),p/ Within NRC, coordination between RES, NRR and fMSS is g *, f Several meetings of the interagency committee t ongoing. / have already been held. A logical framework for N radiation protection standards for the public has been proposed for the working group's consideration and is [ also being reviewed by the NRC staff as a starting point i s SMN 11/05/87 .Y -. - - - _ l ~- ~,. .".';l The tomm'issioners -5 ' foh the possible development of a more cor,sistent overali -i ~ policy for radiation protect. ion criteria. f ~ The Data Base for the Dose Limitation System Regulatory decisions regarding radiation protection depend to a great extent on radiobiological and j epidemiological data. The principal data base supporting, the dose limitation system comes from an epidemiology i study of over 91 thousand Japanese atomic bomb survivors. Of these survivors, 54 thousand received absorbed doses between 1 and 600 rad. According to the 1980 report by the Committee on the Biological Effects of Ionizing Radiation (BEIR) of the National Academy of Sciences, an approximate sample size of 50',000 subjects exposed to a single exposure of 10 rad or more was considered statistically acceptable to tes,t for a small absolute cancer excess. For reasons evident from these statistical considerations,.the BEIR Committee did not provide radiation risk coefficients for populations in which single exposures of less than 10 rad are received. However, to assist government agencies in the establishment of radiation protection standards, the Committee did provide similar risk coefficients for use with large populations subjected to continuous, lifetime exposure rates of 1 rad /yr or more. The BEIR report does aM. state that there are no risks below these exposure levels. Rather, for lower exposures, the uncertainties of extrapolation of risk were believed to be too great to justify calculation. In the development of preventive standards for facility + design and operation, gaps in technology are normally compensated for by adopting conservative assumptions. SMN 11/05/87 ~~ ^ ~~ ~ . f. ' _ ~ ~ - ~ _. 1 t .~ The Commissioners 6.' t F.or. this purpose, hypothetical extrapolation of t'he risk coefficients'for single exposures 'less than 10 red and l continuous, lifetime exposures less than 1 rad /yr have ,j been made for determining radiation-protection policy or j[ prioritizing regulatory programs. However, such ./. extrapolation for predicting the consequences of f (,V 4 exposures to individuals or small groups to small doses .[ cr in establishing below-regulatory-concern and de minimis risk levels should be thoughtfully considered and thoroughly understood since the technical uncertainties are significant. In summary, it is not known whether exposure rates of r j j' about 100 saillirad per year are detrimental to man. O j,' ' Americans receive an average annual dose of about three times this level from the natural environment and man-made sources. Any somatic effects at the 100 s' millirad per year exposure rate would be masked by l environmental or other factors that produce the same types of health effects as does ionizing radiation. O DEFINITIONS, CONCEPTS AND CURRENT ACTIVITIES I Below Regulatory Concern (BRC) 1 . i.Y ' l In recognition of the existence of radiation risks that >e .p c j are sufficiently low to warrant only limited government ,(r' e' J -regulation and attention, Federal and State agencies are attempting to define appropriate BRC thresholds. The risks associated with BRC thresholds are not necessarily l: trivial. However, regulatory implementation of the ALARA concept below these thresholds cannot be justified. -11/05/87 SMN -,.. ~.. ~. ~l .a ' - ~ '. j j e 7 ~ The Commissioners. ~ ) o A BRC threthold pr level may be specified in tems,9f 'j
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~ radionuclide concentration. Current NRC regulations include several instances of the implied use of SRC levels, although they are seldom referred to as such. f i Examples include exempt quantities and concentrations in 2 various consumer and industrial products (Part 30), exempt concentrations of tritium and carbon-14 in animal j carcasses and scintillation fluids ($20.306), and exempt i L quantities of soluble or dispersible radioactive material I for release into sanitary sewer systems ($20.303). These l 1 exemptions were promulgated by previous Commissions, not because they are believed to be risk free but b'ecause the degree of risk is too small to justify the cost of anything more than minimal regulatory requirements. i For example, under $20.306, Disposal of Specific Wastes, 0.05 microcuries or less of hy'drogen-3 or carbon-14, per gram of animal tissue, averaged over the weight of the entire animal, may be disposed of without regard to its i radioactivity. This regulation relieves the licensee of complying'with the regulations governing radioactive waste disposal. However, limited government requirements e remain in effect whereby the licensee is required (1) to perform surveys ($20.201), (2) to maintain records ($30.51), (3) to afford to the Commission opportunity to inspect the material, premises and facilities ($30.52), and (4) to perform, or permit the Commission to perfom, j such tests as the Commission deems appropriate or necessary for the administration of the regulations ($30.53). The licensee must also continue to comply with other applicable Federal, State, and local regulations (S?0.306(d)). Enclosure 1 lists the de facto BRC levels [,., f. already in effect. It should be noted that conceptually 11/05/87 SMN 7,,. ,5 ~ ~ ( . ~ ' f.- The Co'aimissioners -8 l, the'-vJrious BRC levels-cs%-and of te'n do,' differ to 'some d ~W
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degree with respect to the iinplied limiting dose criteria ' J [l[f(.I to individual members of the public. ,.( P p ' "..* g [ y t,., I . Recent Federal actions with regard to SRC include the b[(publicationinAugust1986ofNRCpolicyfort 4.. , I, ,/ deregulation of radioactive waste streams with dose rates .{ .I ' [ no more than a few millirem per year ($1 FR 30839). 3,hI( ' ' ($'/ /? During the latter part of 1988, staff expects to receive l f j, . ',,.. n several petitions for rulemaking to deregulate certain q reactor waste streams under this policy. The U.S. l g Environmental Protection. Agency (EPA) is developing v' generally applicable environmental standards, for land disposal of low-level radioactive waste, which include L* criteria for BRC wastes. EPA is considering a 4 area /yr l BRC individual dose standard. These standards are expected to be proposed in early 1988. I I The NRC published an Advanced Notice of Proposed Rulemaking (ANPRM) in December 1986 ($1 FR 43367), asking for public comment on whether to proceed on generic i: (l deregulation of slightly contaminated (BRC) wastes. The NRC has recently received an unsolicited proposal from Ii the Texas Low Level Radioactive Waste Disposal Authority in collaboration with the University of Texas, to provide technical assistance to compile the necessary data base, estimate the public. health impacts from e variety of disposal options and develop standards and procedures needed for a generic rulemaking. The staff is studying the feasibility of this project and based on the conclusions reached and the evaluation of comments (93 4 11/05/87 SMN h ,g . c4 c 4 s I L'L C. a u N ? alfu4 m Lee.e(.'.'. .ry; idv
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,$lY 4'th it. hisW c.$.'.C48 / kl%/ k $sv/ 44&rA ft/rf G W f bd/ .$.%;ysbj 0Q/ h CCs.Aic$.4tLt*Uh4 (012l't. ,;C 4 /[6 'C.'M v I 44.t.< M id hM Anx m/w.? 9 I I i l l r l l n ) i ~' .~ The Commission _rs e 9 received)ontheANPRM,arecommendationwillbe.madeto the ' Commission for future action. ^ A conceptually related effort ongoing within the NRC is l focused on developing residual radioactivity criteria for decommissioning which would allow termination of licenses and unrestricted release of property. These criteria would, in effect, estabitsh BRC levels for release of slightly radioactive lands, structures, materials and equipment. De minimis This term is usually used in reference to risks considerably lower than BRC levels *, i.e., risks so low that they should be below persona.1 Interest. The tem i "de minimis" is taken from a Latin phrase often translated as '"the law is not c'oncerned with trifles." The word " law" gives the phrase a "Below Regulatory. Concern" connotation, but the word " trifles" disqualifies the phrase for BRC purposes because SRC risks are not necessarily negligible. In common usage, the triviality connotation outweighs the legal connotation, and many people associate the tem de einfais with radiation risks that are negligible or below personal interest. For example, in the United Kingdom the National Radiological Protection Board considers that doses up to 5 aree per year, i.e., 1 percent of the annual dose limit for members of the public, are insignificant as far as the individual is concerned and describes the associated L fatality risk (10.s per year)as too low to be considered I in personal decision-making processes. This number is reduced to 0.5 millirem for individual sources to account for potential exposures from multiple sources. For the 11/05/87 SMN l , _ - _ _.. _.... _ _ -. _. _, _ _. ~,. ~. ~ 1 o
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~, _. l ~ .J -- Tb6 toamissionFrs - 10 ~ ~ ~ j DJorrevision.ofipCFR,Part20;now' underway,NRCstaff, is proposing that doses to individual members of the j public receiving 1 area or less in a year be emitted 'in j collective dose evaluations to prevent an unwarranted-commitment of resources for controlling.or regulating j exposures at levels where calculated risks are negligibly j small. I Use of the term "de minimis" is falling inte disuse. I l Recently, the National Council for Radiation Protection (NCRP) has recommended 1 millires per year as a -" Negligible Individual Risk Level." The decision by the o (. NCRP t.o bypass the tets de minimis has been welcomed by 1. many as the best way to avoid the intrinsic implication. l that it is' appropriate for,the law'to be concerned at risk levels immediately above those that are trivial, L leaving no range in which people are allowed to provide protection on an entirely voluntary basis. Radiological Criteria for Decommissioning Decommissioning refers to removing nuclear facilities safely from service and reducing residual radioactivity to a level that permits release of the property for 1.- unrestricted use and termination of license. Nuclear facilities refers to the site, buildings and contents, ? and equipment associated with the licensed activity. The NRC published an ANPR on decommissioning in March 1978 e i (43 FR 10370) requesting comments on a number of issues j related to decommissioning, including residual radioactivity criteria. However, radiological criteria were separated from this decommissioning rule effort in February 1983. The proposed rule on decommissioning was published in February 1985 (50 FR 5600) and a separate 11/05/87 SMN mr m s tiv n-we r-e. e. w e g --n-e w ,-..--a_ ~' ~~ 'R ^^ .. ' _ J - ~
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11 .~ i_ proposed l rule on. radiological criteria was then develope'd. however, the, supporting draft Generic Environmental. Impact Statement published in January 1981 as NUREG-0586 was not accepted by EPA on the basis that it does not include an adequate analysis of alternatives for criteria for residual radioactivity. A final rule on i decommissioning and a final version of NUREG-0586 are .l scheduled to be published in early 1988. The final rule does not include generic guidance for acceptable levels l of residual radioactivity. s ^ Existing generic guidance for the release of residual levels of radioactivity only provides limits.on-acceptable surface contamination levels. NRC regulations do not contain criteria for acceptable levels of residual contamination in soils. Past decommissionings of reactor facilities have relied on the 1,evels for acceptable surface contamination given in Regulatory Guide 1.86, and, in addition, an imposed limit on external gamma radiation of SpR/hr above natural background, measured at one meter from the contaminated surface. The 5pR/hr exposure rate is an imposed criterion designed to limit the dose to an individual to less than 10 millires per year. The EPA published an ANPR in June 1986 ($1 FR 22264) concerning residual radioactivity in buildings and soils in which it requested comments on several questions concerning the approach that might be taken in criteria development. Although some progress has been made. EPA staff limitations have caused serious delays, suggesting that the guidance may not be ready for at least four years. Since there is a need for near-ters, guidance for current and future decommissionings of nuclear 11/05/87 SMN
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i s. ~ e ~ ) The-Commissioners ' 12 facilit'tes) tie NRC 4taf'f.is' proposing to deveisp for ] ~~ ~ ~~ Commission consideration, an interim policy statement to l be issued in the Spring of 1988, for use until Federal interagency guidance is estabitshed.. As a minimum, the guidance would be expected to establish allowable individual dose limits and would propose a set of acceptable models which can be used to convert contamination levels into dose estimates. The NRC staff. is also developing information which will establish i - acceptable limits for residual contamination at various J types of riuclear facilities in terms of radionuclide concentrations. Staff anticipates that a 10 aren/yr limit for release of residua 11y contaminated facil,ities can be i met by most licensees except in the case of facilities-contaminated with naturally occurring radionuclides. However, for such facilities, higher dose limits may be considered based on cost-risk reduction considerations. A Battelle PNL study is underway to develop a cost 3 l. analysis and to assist with the longer-ters development of implementation guidance. The cost analysis will also be used in the development of Federal interagency guidance. It is expected that contamination levels considered suitable for property release for unrestricted use, as developed in the guidance, will not involve changes to current guidance. As a result, cost estimates for decommissioning would not be expected to be affected. A FRAMEWORK FOR CONSISTENT RADIATION PROTECTION STANDARDS l L The Proposed Framework l As with recently issued Presidential guidance for the protection of radiation workers (January, 1987), presidential guidance will establish a limit on the 11/05/87 SMN r~, -i~ - y ~. ~ ~ 8 - The-Commissioners ~ ~ 13 l ~,. acceptable' annual r.isk hvel for members of'the pub.lic. - For example, a level of 1,00 mren/yr is bein's considered. e ? This level would correspond to a dose limit that.any fndividual may receive from all combined sources subject to regulatory control. The ICRP, for example, recommends 100 area /yr. The ICRP also recommends 500 area /yr if the j lifetime average does not exceed 100 aren/yr. These are - i upper limits and regulatory Al. ARA would be implemented to, reduce risk. A framework has been proposed to account for doses from l multiple sources of exposure and which could include the concept of de minimis or BRC risk levels. Multiple L sources of exposure include, for example, liquid and gaseous effluents from nuclea'r facilities, shipments of. j radiokctive material, waste disposal operations, decommissioned lands and struct,ures, recycled materials and equipment, and radioactivity in consumer products. /, Foreachoneofthesesources,anupperlim5tof. [ one-fourth the annual dose limit would be established. f This is based on the assumption that the probability of 4 / 0[h[ exposing an individual to more than four sources at that c 0 ? level is vanishingly small. In terms of the example \\@, above. each source would be assigned an upper dose limit g e of 25 aren/yr. This would be consistent with existing S regulations as, for example, 25 area /yr from wasta N disposal operations (10 CFR Part'61), 25 aren/yr fres fuel cycle facilities (40 CFR 190), and 25 area /yr from other types of facilities (Clean Air Act). In addition, regulatory Al. ARA (e.g., Appendix I,10 CFR Part 50) would be required for each source in order to control risk. A generic BRC level, if developed, would be expected to be of the order of a few arem/yr (for example, 5 11/05/87 SMN r+- , '. <, [ *.,.. 0.3 ~ ~ -The Comissioners ' .~ R ~ mrom/yr), _This.would be.a sah11_,fract' ion of.the annual dose limit to the individual (100 mrom), and a very small. fraction of the average annual dose to the individual from natural background and man-made sources (300 ares). An established generic BRC level would avoid large-expenditure requirements and unnecessary deployment- - of resources for the protection against very low risks. I An established BRC level night also serve to reduce ,public concerns about small doses. Selow the SRC level, risk reduction would be entirely voluntary. For a p'articulaf source 'witVan.associatedYxposurilevel below the BRC level, regulatory decisions and licensing actions L can be made'in an' expeditious manner and licensing l requirements would be limited. ' Regulatory decision criterta to accept or reject t$e risk associated with possession, use, transfer or disposal of radioactive materials would geiwrally.be based on the. x impact on public health and safety and the environment and on cost-risk reduction' considerations. In the dose framework, any operation associated with a risk level greater than the established acceptable annual health risk limit would not be authorized. - An operation associated with a risk level less than the acceptable annual risk, but greater than the risk associated with a L generic BRC, or de minimis risk level could be authorized t based on a sound ALARA analysis.- An operation associated with a risk level less than the risk associated with.tRC or de miniais would be acceptable and authorized without cost-risk reduction considerations. For example, assume that the BRC level has been established at 5 mrom/yr and that* residual radioactive contamination at a decommissioned reactor facility results in dose projections of 10 arem/yr to an individual member of the 11/05/87 SMN l ' ~ .g.~ ~ ~ n ** ) .~ ~ The Comitssioners 15 ~ ~ L., r \\ ~ l ' public. The~ facility inay,be authorized for. release for ~ unrestri$ted use if'it is economica11y lmpractical to ~ ~ ~ attain further reduction of contaminant levels. As a r second example, a consumer product such as radioactive [ gemstones may be exempted from certain parts of the regulations on the basis of projected annual dose being 'less than the de minists risk level. Cost-risk reduction l considerations would be unnecessary in this case. To pemit a comprehensive treatment of the subject, the de minimis risk concept could be included in the framework.,This level would be a fraction of the BRC l' vel. In the range between BRC and de minimis, e conditions may be imposed, but governme'nt, requirements [ ' for imposition of ALARA is not justified and risk control is' voluntary.' In the range be16w de minimis, risks should be of no interest to anyone. POTENTIAL POLICY OPTIONS l The staff has identified four broad conceptual options for application of de minimis and below regulatory concern concepts into Commission policy. Under all l options, regulations would continue to be based on the following principles: (1) the benefits to individuals or society should justify the imposition of the calculated radiological risks and (2) the exposures to members of the public shoul,d not exceed recommended dose equivalent limits. The principal objective of these options is to present a set of logical bases for establishing levels of risk below which' government regulation should be limited or unwarranted. As a result, the options provide, as a minihium, thresholds of risk below which ALARA principles G k 11/05/87 SMN -m m ~ ._,------...,..u A fp ~sj.g -F.. ~
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. \\.. ~ .'~ ' ~ ~ ~ ~~ The, Commissioners '16, e. no, longer need to be applied'to reduce potential.., 4 radiological exposures. OPTION 1 - Continue t'o Implement the Current Dose Limitation System Without Modification The current system for limiting-' exposure, i.e.,- regulatory dose limits and ALARA policy, continues to be, implemented without establishing risk levels below which government regulations are limited or unwarrante.d. . Regulatory act' ions such as special exemptions from parts of the regulations and the enablishment of case-specific. "8RC" levels are implemen'ted as needed.- . OPTION 2.- Implementation of the De.Minimis or, Negligible Risk Level l ~. .Add a single lower-cut-off level i.e., a de minimis risk level to the current dose limitation systas. The-establishment of a-de minimis risk level would provide a cut-off below which any health risk, if present, could be 5 considered negligib'le. As a result, gover mlot regulation of any kind would not be warrantwo-for operations with associated radiological impacts below the de minimis level. The determination of a de minimis risk level would be E.I based.on individual and. societal risk considerations. Neither, the benefit of the activity nor the monetary costs associated with " activity-related" dose reductions would be pertinent to the negligible, risk determination. Rather, comparative risk arguments such as comparisons to natural background and its fluctuations, and a reexamination of the dose / health' effects dat'a base would 11/05/C'! SMH ~_ u M.7., o,4,..,,.. p .I f w . e -w ,_~ .. t - '- The' Commissioners- .~ 17.*- ~' ~ ~ +n be expected to provide major justifications f'or a de * ~ -i Tminimis risk deterairiat4on. OPTION 3 -Development and Implementation of j Beinw-Regulatory-Concern Concept on a " Source-Specific" or Generic Basis j Source-specific BRC levels exist in the regulations and the concept continues to be reflected in current Commission activities. For example, the design-objectives for effluent releases from light water nuclear power reactors can be considered a " source-specific" 8RC standard. Other examples include the established regulatory criteria for' declaring waste streams to be below regulatory' concern and the developing of interin'. , criteria for the release of residual radioactivity. The conc'ept of BRC is based on'*an acceptable or justified ' '~ ( risk as opposed to a de minimis or negligible risk. L Costs, benefits and potential health risks are considered in establishing a source-specific BRC level. As a-result, BRC levels would generally be less restrictive r -(i.e., greater risk) than limits established under de minimit or liegligible r'isk principlet.. ' ,l [ * ,f., A single gener.ic BRC limit would be subsequently j established by 'xt'rapolation from existing, individual l e " source-specific" BRC levels. Since cost-risk a'nalysis 'has been considered in establishing.the cost-specific 1evels, regulatory implementation of Al. ARA would cease at L the generic BRC' level. The difference between a generic L BRC risk level and a de minimis or negligible risk level would be one of degree, where the risk associated'with 11/05/87 SMN e ~ _~
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_ - = r g,..op_ - Lr.-; r s - The Cosimissioners '. 18 ,.; =,. ' the generic BRC level 'is greater t.han that considered. -a ~. ~ ~ de minish. w OPTION 4 - Implementation of Both De minimis and BRC. Concepts This option provides the greatest number of." risk zones"- into which the potential exposures associated with a nuclear activity can be placed. Between the maximum. individual _ dose limit and a generic BRC level, the ALARA approach to dose li,sitations would apply.- For " sources" associated with, individual or population. doses below the BRC level,-regulatory involvement would be limited - and regulatory imp 1ementation of At. ARA not be re, quired. v.. n 4 s c g 11./05/87, SMN -