ML20199C746
| ML20199C746 | |
| Person / Time | |
|---|---|
| Issue date: | 11/13/1998 |
| From: | Mcgaffigan E NRC COMMISSION (OCM) |
| To: | Hoyle J NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML20199C723 | List: |
| References | |
| SECY-98-225-C, NUDOCS 9901190102 | |
| Download: ML20199C746 (28) | |
Text
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NOTATION VOTE RESPONSE SHEET
- TO: John C. Hoyle, Secretary FROM: COMMISSIONER MCGAFFIGAN
SUBJECT:
SECY-98-225 - PROPOSED RULE: 10 CFR PART 63
- DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN A PROPOSED GEOLOGIC REPOSITORY AT YUCCA MOUNTAIN, NEVADA" Approved x Disapproved Abstain Not Participating COMMENTS:
See attached comments.
0 .
1.I Edward McGaffiqan, JE
- SIGNATURE November 13. 1998 DATE I Entered on "AS" Yes x .No ._
9,.,,;,conceen"!8Mi38P2 poace m
Commissioner McGaffican's Commems on SECY-98-225:
I approve publication of the notice of proposed rulemaking for 10 CFR Part 63 specific to the proposed geologic repository for high-level waste at Yucca Mountain (YM), Nevada. I also commend the staff for meeting an extremely tight schedule for submitting the proposed rule for Commission approval and, in response to recent Commission direction, making the staff paper available on NRC's website. I offer the following comments for the staff's consideration.
General Comments:
I am convinced that now is the most appropriate time for NRC to publish its proposed rule for public comment. NRC clearly has an important statutory role in the development of technical criteria and requirements for the geologic disposal of high-level waste. NRC's role was first defined in the 1982 Nuclear Waste Policy Act and again in the 1992 Energy Policy Act (EnPA).
In 1995, the National Academy of Sciences' (NAS) issued its recommendations on the appropriate technical basis for health and safety standards for the YM site, as mandated by the EnPA: The EnPA charged the Envircnmental Protection Agency (EPA) with promulgating generally applicable standards consistent with the NAS findings and recommendations not later l than one year after the NAS report was made available to EPA. EPA is now more than two years overdue in meeting this deadline. The EnPA also charged NRC with promulgating conforming standards consistent with EPA's to be issued one year after EPA's final standards are l
promulgated. The EnPA in no way prohibits NRC from starting its rulemaking in the absence of EPA standards. Ind:ed, the time for netting started is now. The Department of Energy (DOE)is facing major milestones and decision tuming points in the YM proicct and DOE has made clear its need for the availability of NRC standards by 20u). In order to meet this schedule and not negatively impact the nationai waste program, and allow ample opportunity for participation and comment by all stakeholders and other interested parties, NRC must proceed expeditiously with issuance of this rule for public comment. It is through a public process that NRC can ensure the establishment of sound and scientifically defensible standards for YM. Eventually, NRC must make sure that its standards are consistent with whatever standards EPA ultimately issues or Congress ultimately mandates, but that eventual conforming, if needed at all, will go more quickly and easily,if NRC begins its work now.
Specific Comments:
Use of an all-pathways standard: I firmly believe that adequate protection of the public is fully afforded by use of an all-pathways expected dose limit of 25 millirem per year to an average member of the critical group. The all-pathways approach is consistent with recommendations of the Congressionally-chartered National Council on Radiation Protection (NCRP), the Intemational Commission on Radiation Protection (ICRP), the NAS study on YM, and the most l
! recent House and Senate versions of high-level waste legislation. The all-pathways approach was also supported by the Health Physics Society, the NRC's Advisory Committee on Nuclear l Waste, and many commenters during promulgation of NRC's license termination rule (LTR) in 1997. As the staff points out, the 25 millirem per year starGrd is also consistent with existing requirements for management and disposal of other waste facilities including to CFR Parts 61
2 (low-level waste) and 72 (spent fuel) and EPA's 40 CFR 191 (spent fuel, high-level and transuranic wastes).
The grmmd water pathway: The all-pathways approach fully considers the dose contribution
! from the groundwater pathway and therefore the need for a single, separate standard for ground water is obviated and cannot be justified on a health and safety or cost-benefit basis. Unlike the
! Waste Isolation Pilot Plant (WIPP) m New Mexico where the ground water pathway is not an l issue, there is potable water at the YM site and therefore, the ground water pathway must be l adequately protected. Implementation of an all-pathways approach effects this. Singling out the ground water pathway and applying a more restrictive standard as recommended by EPA has the effect of convening an overall system performance standard in the millirem range to a sub-millirem standard that may not be implementable at a site with potable water and far exceeds any requirement for public health and safety. Specifically, applying EPA's Maximum Contaminant Level for iodine-129 in ground water, results in an individual dose of approximately 0.2 millirem per year. This dose is extremely small when compared to typical exposures to an individual from various sources of natural background radiation. For example,0.2 millirem per year is u approximately two orders of magnitude smaller than the difference between the individual dose
! received from natural background when living at sea level versus living at the altitude in the vicinity of YM. and is approximately one twenty-fifth of the average dose from a transcontinental flight. In my opinion, applying a separate ground water standard unnecessarily adds complexity and costs and results in duplication of the all-pathways analysis for no value or
- health and safety benefit. I do not believe that it is good public policy to expend significant l
resources to regulate at a level that represents such an extremely low tisk to the public.
" Average member of the critical group" aproach: I fully support the use of the " average t member of the critical group" approach. This approach is consistent with the ICRP practice of defining and using a critical group approach based on cautious but reasonable assumptions when assessing individual public exposure from low levels of radiation. It is also corsistent with NCRP recommendations, the NAS findings, and it has been adopted by both NRC in i's cleanup mle and EPA in its 1994 draft Federal Radiation Protection Guidance for Exposure of the General Public.
l Time of compliance: I also fully support the proposed time of compliance of 10,(X)0 years since the inherent radiological hazard of spent fuel decreases rapidly and significantly during the initial 10,000 year period (99.9 % of the hazard has diminished at 10,00() years). It is also sufficiently l long such that a range of geologic conditions can be assessed during this time period, and EPA l has already codified a 10,000-year compliance period in 40 CFR 191 applicable to WIPP.
I Human intrusion: I look forward to public comments on the proposed stylized human intrusion scenario since certain assumptions could be considered by some to be overly conservative, e.g.,
borehole drilled through a waste package all the way to the saturated zone. Also, the statements of consideration indicate that DOE is to assume that the borehole is not adequately scaled
- however, section 63.113 is silent on this issue. These sections need to be made consistent for clarity.
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Changes to the safetyprogram: It appears that proposed section 63.44 applies a 10 CFR 50.59- f like change process to the entire contents of the license application rather than only the Safety l
Analysis Report (SAR). As a result, implementation of the proposed requirements for Commission approval, reporting and recordkeeping of certain program changes has the potential to be quite burdensome for both the applicant and regulator. Proposed language for Parts 50,52, l and 72 would all suggest that the 50.59-like change process be applied only to the SAR. Also, l the staff should consider Commission direction in a staff requirements memorandum dated l September 25,1998 (SECY-98-171) to modify 10 CFR Parts 50,52 and 72 to allow minimal l
increases in the probability of occurrence or consequences of an accident or malfunction of equipment and minimal reduction in the margin of safety without the necessity of submitting a license am ndment. The staff should modify section 63.44 to incorporate language equivalent to that proposed for 10 CFR 72.48, including making conforming changes to sections 63.44 and 63.46 to climinate the concept of an "unreviewed safety question."
The Federal Reelster notice: Like the recerit proposed rulemaking package on Part 35, the staff l should consider consolidating all the questions soliciting public comment located throughout the FRN into one section for case of the reader. The questions should not necessarily be removed from their respective subject areas so as to keep them in context.
Specific edits on the Federal Recister notice, press release and letters to Congress are indicated on the attached pages.
The IIcaring Process:
In the HLW context we have an opportunity to take decisive steps toward more open, less formal, hearings, for both construction authorization and licensing to receive and possess waste.
No statute dictates what sorts of hearings we have in these two contexts, and no tradition of formal hearings carries an inertial force against needed change. To the contrary, EPA's non-adjudicatory handling of the Waste Isolation Pilot Project is a precedent for change.
Although Part 2 Subpart J, which covers hearings on an application for a license to receive and possess waste,is a well-considered set of regulations, with many of the virtues praised in our recent Policy Statement on Adjudications, proceedings under Subpart J are still formal. As the SECY paper notes, cross-examination is said to be a virtue of formal hearings. While it may have its uses, it is strikingly enough not a widely valued tool in technical and scientific professions, where inquiry and sustained questioning are nonetheless crucial. Our procedures.
whether in hearings or in the staff's reviews of the application, should leave plenty of room for l
inquiry and questioning; but it is not clear that those procedures must leave room for crow l
j examination, which is a specialized form of questioning that has evolved within the contenuous, but not always inquiring, atmosphere of the courts.
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Doing away with the unnecessary trappings of trial is not enough, however. I have argued before that formal processes are too restrictive as to who may speak, where they may speak, what they may say, and how they may say it. It will not be enough to make hearings less formal. We must also make them more open. I focus here on one aspect of openness, namely, standing. If we make the two repository hearings less formal but retain current formal standing requirements, !
which are essentially those of Part 2 Subpart G for formal hearings, we will have succeeded in i ruling out as interveners organizations that do not have a base near the repository or do not have the time for a tria.1 (UCS, NRDC, and Public Citizen among them), but who nonetheless might make a contribution to the technical and policy discussions involved in the licensing of the repository. I have said before that we should look to Icgislative hearings as one model for )
informal hearings. It is common in legislative hearing 3 for relatively disinterested but nonetheless expert persons to participate. Contrast that with the approach that is too often taken in formal hearings, where the party must always be interested and is sometimes very inexpert.
The advantages of formality are not obvious in such cases.
1 I believe that the FedcM Recister notice in which the proposed Part 63 is published should say that the Commission's present inclination is to conduct rulemaking that would provide for informal hearings for both authonzation of construction and licensing of receipt and possession of waste. Attached is one way of saying that.
I would also direct OGC to develop a proposed rule for mformal hearings for both of these '
stages. Because the licensing p ecess for the HLW repository is broken into stages and opportunity for hearings attach to raore than one of the stages, the proposed rule should include, among other things, some provision that gives the appropriate degree of finality to decisions made in earlier hearings. For example, such a provision might say that issues that were, or could I have been, litigated and resolved in a hearing on construction authorization would be revisited only if significant new information that could alter the original findings was brought forward.
The same provision could also say, drawing on 10 CFR 52.103(c), that only the Commission had I
the authority to reopen an issue. The provision might also say under what circumstances,if any, operation could go forward while the original finding was being revisited.
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1 Attachment
[ Revision of paragraph over the break between page 7 and page 8 in the FRNi As part of its broader. efforts to improve the effectiveness of its programs and processes, the Commission has a study of the NRC hearing process underway which includes the process that would be used for repository licensing. If, on the basis of this study, the Commission inlc w concludes that changes to the hearing process are warranted, it will propose them for adoption in a separate notice and comment rulemaking. Ilo,w,u, iln this rulemaking, the Commission is not seeking comment on potential changes to the hearing process. However,in the interests of openness, the Commission wishes to say that, at present, the Commission is inclined to provide for informal hearings for both construction authorization and licensing to receive and possess waste. No statute requires formal hearings in either case; EPA conducted none in certifying the Waste Isolation Pilot Project; and informal hearings allow for both greater efficiency and greater openness. The Commission has directed the staff to prepare a draft rule that could be issued for public comment should the Commission conclude that changes to the hearing procedures for construction authorization and licensing to receive and possess waste are warranted.
development in parallel with development of EPA's standards. Following publication of the NAS l i 1
report, NRC staff met frequently with EPA staff to discuss the report and associated issues l
relating to development of new EPA standards and NRC regulations. NRC is continuing to work with EPA in the development of reasonable and implementable standards for Yucca Mountain that are protective of public health and safety. The Commission believes, as noted below, that it is in the best interest of the national program to proceed with promulgation of its l implementing regulations. It is recognized that when EPA issues its final standards, or if e ocleA' d h pending legislation affecting the regulation of the nation's HLW program is pa;;cd and-sxjned'
. M he Iicsicsat,Wthese proposed regulations may need to be amended.
At the same time, the DOE program for charactenzing the Yucca Mountain site as a potential geologic repository is continuing. A viability assessment of the site will be completed in late 1998. Following that, it is expected that DOE will' publish a draft envircnmentalimpact statement (EIS) in 1999. with a final EIS to be completed in 2000, such that a site suitability recommendation can be made in 2001. Assuming that the Yucca Mountain site can be J l
recommended for development as a geologic repository, DOE would then submit a license l
application to NRC in 2002.
In order for DOE to commence preparation of a license application and to permit timely and significant public involvement in the development of implementing regulations, the Commission believes it has an obligation to make public now how it would implement dose- or risk-based standards for Yucca Mountain.
As part of its broader efforts to improve the effectiveness of its programs and processes, l the Commission has a study of the NRC heanng process underway which includes the process that would be used for repository licensing. If, on the basis of this study, the Commission believes that changes to the heanng process are warranted. it will propose them for adoption in l 7 i
Ill. Development of a New 10 CFR Part 63 As discussed above, the Commission is directed by EnPA to modify its requirements for geologic disposal within a very short time to implement site-specific standards for Yucca Mountain. The legislation also specifies the type of standards NRC is to implement (i.e.,
standards which limit individual dose, and which are based on and consistent with the NAS recommendations). In view of these constraints, the Commission is proposing to establish a new, separate part of its regulations at 10 CFR Part 63 that will apply only to the proposed repository at Yucca Mountain. The Commission is also proposing to leave its existing, genene regulations at 10 CFR Part 60 in place, modified only to indicate that they do not apply, nor may they be the subject of litigation, in any NRC licensing proceeding for a repository at Yucca Mountain. The Commission believes this to be the most direct and time-efficient approach to the specification of concise, site specific critena for Yucca Mountain that are consistent with current assumptions, with site-specific information and performance assessment experience, and with forthcoming EPA standards that must also apply solely to Yucca Mountain.
In establishing these enteria, the Commission seeks to establish a coherent body of risk- )
l informed, performance-based enteria for Yucca Mountain that is compatible with the i
Commission's overall philosophy of nsk-informed, performance-based regulation. Stated ;
succinctly, risk-informed, performance-based regulation is an approach in which risk insights, engineering analysis and judgfment, and performance history are used to (1) focus attentica on X e
the most important activities, (2) establish objective enteria&5cd upon risk insights'for x l evaluating performance, (3) develop measurable or calculable parameers for monitoring
! O system and licensee performan]ce and % focus on tie results as the pnmary basis for regbtory decision-making. The Commission believes that the creation of a new part of its (4) pole _ b4 h A t6 m^ u hw M n cc +- % es twheA d fbMS
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p-V. Individual Protection Standard for Postclosure Repository Performance As already stated, the authority and responsibility for setting public health and safety standards for radioactive waste disposal at Yucca Mountain rest with EPA. It is NRC's l
responsibility to implement those standards in its licensing actions and ensure that public health and safety are protected. The Commission is proposing an individual dose limit which it believes is generally consistent with EnPA and with the conclusions and recommendations of NAS. Although EnPA required that EPA specify a limit based on individual dose, NAS recommended a limit be established on risk to individuals (i.e., the probability that an !ndividual or individuals receive an adverse health effect). An equivalent level of radiation protection is afforded individuals by a standard expressed either as a nsk or a dose limit when the evaluation l l
of dose or risk considers the probability of incurring a dose and both limits are based on similar )
dosimetry assumptions (i.e., consistent dose to health effects conversion). In previous ;
I rulemakings, the Commission has used either implicitly or explicitly a constant total effective dose equivalent to health risk coefficient (i.e., FR 39061; July 21,1997), and thus, for a given probability of occurrence, the health risk can be related to a unique value of dose. Additionally, the Commission is proposing an individual dose limit because the Commission believes that a ;
dose limit may be more readily understood by the public and is the form of a standard more frequently used to regulate nuclear activities. When EPA issues final standards for Yucca Mountain, the Commission will amend its entena at 10 CFR Part 63, if necessary, to be consistent with the final standards As a licensed. operating facility, a repository at Yucca Mountain would be subject to the existing regulations at 10 CFR Part 20 that require. among
\ other things, doses to members of the general publ':1) not exceed a total effective dose x 4; HLU 16
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, y ar a k x r .? t L.t equivalent of (TEDE) 1 mSv (100 mrem) per year in addition, prior to permanent closure, g l . n \, <, M l repository operations would need to be conducted such that public exposures be maintained as epe A N V .<
low as reasonably achievable. When the repository is closed, surface facilities must be 6 4 ,J l
6~ck wt decommissioned in accordance with 10 CFR Part 20, Subpart E. Finally, during normal rd. <s
.w ,,,4 I operations and anticipated operational occurrences, the annual dose to any real member of eg public, located beyond the boundary of the site, shall not exceed a TEDE of 0.25 mSv # "~' I
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(25 mrem). This final dose limit, used in this regulation, is adapted from the dose limits N .b 7 c
.g y ,< A specified in 10 CFR Part 72, for effluents and direct radiation during normal operations and \,wr el i 2 hwies rv anticipated operational occurrences, associated with a monitored retrievable storage installation %u f~ p c L.
(MRS) Like an MRS facility, the operations area at Yucca Mountain is expected to be a large g industrial facility equipped to handle the loading, unloading, and decontamination of spent fuel i'
! and HLW shipping casks; the removal and packaging or repackaging of spent fuel assemblies and HLW canisters; and the sealing, handling, transport, stowage and penodic monitonng of canisters to contain the spent fuel and HLW during operations. Because the activities contemplated for the operations area prior to repository closure pose similar radiological hazards, during normal . operations and anticipated operational occurrences, to those posed at an operating MRS, the Cornmission is proposing that the dose limits for the operations area be i
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A those applicable for the MRS, from planned discharges and from direct radiation during operations. (Radiation from other fuel cycle operations, anticipated for an MRS or independent L spent fuel installation (ISFSI) that might be co-located with other operating nuclear facilities, is not anticipated at the operations area, because fuel cycle operations are not likely to be located in the region). The 0.25 mSv (25 mrem) limit also provides consistency with requirements for
[ other waste management facilities (e g. 40 CFR 191.03(a),10 CFR 72.104. and 10 CFR 6140) ns . r4 A pi, , nec- wm n - Tutw a m gre.a dew lim w din JL w e d pet abd dues r qy s,A A L, ne eu , a ic ca u . i q 1,4 J p5 - ( u , u a p , m ,m,m c y
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To identify an appropriate objective for repository performance after permanent closure, the Commission seeks to establish a constraint that, if met, would provide reasonable assurance that doses to members of the general public will remain below acceptable levels.
International guidance on dose limits suggests establishing constraint limits for specific sources (such as a HLW repository) to ensure that exposure to members of the public from ALL sources G elud y bc.c k ycad mh6m , 3 x is less than the public dose limit. In the case of operational releases, compliance with the requirements of 10 CFR Part 20 can be expected, based on Commission experience with its other licensed facilities. to limit effluents far below the public annual dose limit of 1 mSv (100 mrem). For postclosure exposures, the performance of the repository must depend on passive systems limiting the exposure. Therefore, the perfor,*,anca objective for postclosure l
y must be established such that the public would not receive doses, from al' possible sources, in T
excess of 1 mSv (100 mrem) per year. ey d&c, bany d I v Na h en The Commission proposes a limit of 0.25 mSv (25 mrem) to the total effective dose equivalent, received in a single year and weighted by the probability of occurrence, by the average member of the entical group, as the overall system performance objective for the repository, following permanent closure. This criterion would limitthe dose received from all possible pathways to the entical group at Yucca Mountain, including direct exposure, dnnking of contaminated water, eating food that was irrigated with contaminated groundwater or grown in contaminated soil, exposure to airborne releases, etc. The Commission believes that application of a single, all-pathway standard is protective of public health and safety, and obviates the need for separate, single pathway limits. The Commission established the 0.25 l mSv (25 mrem) annual dose limit as the overall safety objective for both decommissioning of i nuclear facilities (10 CFR 20.1402) and for low-level radioactive waste disposal facilities (10 CFR 61.41). It is within the range of intemational constraints that allocate doses from high 18
i level waste disposal to between 0.1 and 0.3 mSv (10 and 30 mrem) per year, and is comparable to the risk range recommended by NAS as a reasonable starting point for EPA's rulemaking (a risk range of between 104 and 104 per year, approximately equivalent to annual doses between 0.02 and 0.2 mSv (2 and 20 mrem)). The Commission believes that 0.25 mSv (25 mrem) per year is sufficiently below the pub lic dose limit that no members of the public near c4dq bck nwl la Ukm '
Yucca Mountain would be expected to receive doses from all source in excess of 1 v (100 mrem) per year. Estimates of potential exposures at Yucca Mountain are expected to be probabilistic because these estimates will consider variability and uncertainty in the features and processes, and a range of events each with specific probability of occurrence over the time period of interest at the site. The Commission proposes that an expected annual dose, based on the probabilistic results, is representative of individual risk and would be compared to the individual protection standard for determining compliance. Calculation of the expected annual dose incorporates the probability that the estimated dose will occur (i.e., annual dose estimates consider the probability of the occurrence of the events and the uncertainty and variability of the parameter values used to desenbe the behavior of the geologic repository).
VI. Reference Biosphere and Critical Group for Yucca Mountain in addition to establishing an individual protection limit as an overall system performance objective, as discussed above, it is necessary to specify the individual or individuals for whom the performance calculation is to be made, as well as the environment in which the individual (s) reside, and the relevant pathways for potential exposure. In this regard, the NAS observed that the appropriate objective should be to " protect the vast majonty of members of the public while also ensuring that the decision on the acceptability of a repository is not prejudiced by the risks 19
development of exposure scenanos because such exposure scenarios can be based on empirical knowledge rather than unconstrained speculation. The use of current information is intenced to placa primary emphasis on the provision of a framework for analysis of repository performance, rather than on the precise prediction of possible futures.
Requirements that the biosphere be based on arid or semiarid conditions and that climate evolution be consistent with present knowledge of natural climate change reflect a philosophy that, while societal behaviors cannot be predicted, certain aspects of the evolution of natural systems over long time frames can be predicted based on the geologic record. Climate change studies for the Yucca Mountain region indicate that the Yucca Mountain climate could become cooler and wetter following the next ice age; however, analyses of the fossil records from the previous ice age indicate that the climate in the area south of Yucca Mountain is likely to change. at most to conditions consistent with a semrarid climate classification. Decause the current interpretations of the fossil record support these choices for local climate now and into the future, it is reasonable to limit the scope of assumed climate change to these possibilities.
The change from and to semiarid conditions is not expected to alter the biosphere sufficiently to cause major changes in potential exposure pathways to the entical group. For a farming critical group, a semiaod farming region would be expected to support agricultural crops similar to those grown in present day Amargosa Valley. Although specific biosphere and critical group parameters may change slightly with climate, major changes in behavior and exposure pathways for the critical group are not assumed.
DOE will need to establish and defend the particular characteristics, behaviors and attnbutes it assumes for the critical group and referen:e biosphere subject to the requirements and specifications of 63.115. Then, as suggested by ICRP, a hypotheticalindividual 25
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technical, policy, and legal considerations. In fact. NAS noted that EPA might elect to establish consistent policies for managing comparable nsks from disposal of long-lived hazardous materials. From a technical perspective, for example, the time-dependent variation of the hazard, along with the time required to evaluate adequately the waste isolation capability of both engineered and natural barriers, are of significance. From a policy perspective, on the other hand, the practical utility and relative uncertainty of extremely long projections of health consequences, along with the need to maintain a consistent regulatory approach for like hazards, need to be weighed. Having considered both technical and policy concerns, the Commi3sion is proposing the use of 10,000 years for evaluating compliance with the system g g en performance objective at 5 63.113. Should EPA issue final standards for Yucca Mountain that "
put,q specify a different compliance penod, the NRC will amend its cntena at 10 CFR Part 63, as HwJ ig,sk6 necessary, to comply with EnPA requirements for consistency with final EPA standards. A tw The Commission makes its proposal on the basis of three considerations First, the inherent radiological hazard of spent fuel decreases rapidly and significantly during the initial 10,000 years due to radioactive decay dominated by fission products, with the relative hazard diminished by approximately 90 percent at 100 years,99 percent at about 1,000 years and i 99.9 percent at 10,000 years. At 10,000 yoars following waste emplacement, the relative radiological hazard is within a factor of ten of the hazard posed by a quantity of 0.2 percent uranium ore equivalent to that which was necessary to produce the spent fuel (Final l Environmentalimpact Statement on the Management of Commercially Generated Radioactive Waste, DOE,1980; NRC High-Level Radioactive Waste Program Annual Progress Report; l
Fiscal Year 1996, NRC,1997). Beyond 10,000 years the relative hazard of t'e disposed waste diminishes very slowly over several hundreds of thousands of years because decay at such late times is controlled by the activity of longer-lived radionuclides. A 10,000-year compliance l
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features of a specific site or design. This flexibility was provided at S 60.113 (b).
Since their promulgation, the subsystem criteria in 60.113, in particular, have not gained broad acceptance in the technical community. These enteria have been criticized as
.T overly prescriptive, lacking in both a strong technicci basis and a clear technical nexus to the overall performance objective (i.e., the EPA standards), and unclear in their wording.
In contrast to the state of performance assessment technology assumed at the time Part 60 cnteria were put in place, the NAS Committee on Technical Bases for Yucca Mountain Standards found, in 1995, that the physical and geologic processes relevant to a Yucca Mountain repository. " ..are sufficiently quantifiable and the related uncertainties sufficiently boundable that the performance (of a repository) can be assessed over timeframes dunng which the geological system is relatively stable or varies in a bounc:able manner." As has been described earlier, it was a lack of confidence in this capability to quantify overall performance and adequately bound uncertainty that factored prominently in the Commission's decision to include quantitative subsystem requirements in the Part 60 regulations. Also, as discussed earlier, NAS cautioned against implementation of multiple barriers through the use of subsystem performance requirements. In addition, the Commission's Advisory Committee on Nuclear Waste (ACNW) recently recommended that the Commission implement the concept of defense in depth by ensuring that the effectiveness of individual barriers be identified explicitly in the total system pedormance assessment (TSPA), but specifically did not endorse the establishment of rule-based subsystem requirements for Yucca Mcuntain. The ACNW noted that " ..an overall performance-based regulation in the context of a nsk based standard is a superior tool for promoting safety relative to imposed subsystem requirements (see letters
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of waste at Yucca Mountain, so tnat the Commission may find, with reasonable assurance, that i l'
the repository system will be able to achieve the overall safety objective over timeframes of thousands of years. Geologic disposal of HLW is predicated on the expectation that a portion of the geologic setting will act as a barrier, both to water reaching the waste, and to dissolved radionuclides migrating away from the repository, and thus, contribute to the isolation of radioactive waste. Although there exists an extensive geologic record ranging from thousands to millions of years, this record is subject to interpretation and includes many uncertainties.
These uncertainties can be quantified generally and are addressed by requiring the use of a multiple barrier approach; specifically, an engineered barrier system, consisting of one or more distinct engineered barriers, is required in addition to the natural barners implicit in a geologic setting. Similarly, although the composition and configuration of engineered structures, as well as their capacity to function as bamers. can be defined with a degree of precision not possible !
for natural barriers, it is recognized that except for a few archaeologic analogues, there is no j i
experience base for the performance of complex, engineered structures over periods longer than a few hundred years. It is expected that DOE will demonstrate that the natural barriers and the engineered barrier system will work in combination to enhance overall performance of the geologic repository.
The Commission believes that tnis approach to multiple barriers is consistent with the NAS' conclusions and recommendations cited above. The Commission also recognizes, and
< believe t is important to acknowledge that expenence and improvements in the technology of performance assessment, acquired over more than 15 years. now provide significantly greater confidence in the technical ability to assess comprehensively overall repository peric"qcnce, and to address and quantify the correspond'og unceainty in addit;on to extensive reviews of evolving TSPAs produced by DOE and its contractor! . the Commission. uself, has developed 36
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proposes that the results of performance assessment shall be the sole quantitative measure used to demonstrate compliance with the postclosure individual dose limit.
In order to find that issuance of a license will not constitute an unreasonable risk to the health and safety of the public, the Commission must have reasonable assurance that the l
required performance assessment has demonstrated that, following permanent closure, for the duration of the compliance period and considering the likelihood of occurrence of adverse e g d ed.
natural events,pannuakexposures to the average member of the critical group will not exceed j the individual dose limit of .25 mSv (25 mrem) TEDE. Although the performance objective for the geologic repository after permanent closure (& 63.113) is generally stated in unqualified l terms, it is not expected that complete assurance that the requirement will be met can be presented. A reasonable assurance, on the basis of the record before the Commission, that the performance objective will be met is the general standard that is required. Proof that the geologic repository will be in conformance with the objective for postclosure performance is not to be had in the ordinary sense of the word because of the uncertainties inherent in the !
understanding of the evolution of the geologic setting, biosphere, and engineered barner system. For such long-term performance, what is required is reasonable assurance, making allowance for the time penod, hazards, and uncertainties involved, that the outcome will be in l
conformance with the objective for postclosure performance of the geologic repository.
Demonstrating compliance, by necessity, willinvolve the use of complex predictive models that are supported by limited data from field and laboratory tests, site-specific monitoring. and l
natural analog studies that may be supplemented with prevalent expert judgment. Further, in reaching a determination of reasonable assurance, the Commission may supplement numerical analyses with qualitative judgments including for example, consideration of the degree of l
! diversity or redundancy among the multiple barners of the geologic repository. ,
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l or engineered barriers over a period of 10,000 years. The NAS report recommended that l human intrusion be excluded from the performance assessment, but that the consequences of L an assumed human intrusion scenario should be calculated to determine if repository l
performance would be substantially degraded as a result of the intrusion.
The Commission agrees with the NAS recommendations to consider human intrusion apart from the risk-based performance assessment. To permit consideration of the potential detriment from human intrusion in the evaluation of repository performance, the Commission proposes that DOE be required to perform a consequence analysis that includes an assumed intrusion scenario as specified at @ 63.113(d). This consequence analysis would be identical to the performance assessment, except that a specified human intrusion scenano is assumed to
. occur. In the event of this assumed scenario the repository is required to perform such that the T
conudd .(o the average member of the entical group is also within allowable limits. Haz j A ose l intruders themselves (drillers, miners, etc.) or to the public from material brought to the surface 1
by the assumed intrusion should not be included in this analysis, according to NAS This is because, NAS asserts, analyses of these hazards would be unlikely to provide any useful basis for judging the resilience of a particular repository or design to intrusion.
The Commission does not intend to speculate on the virtual infinity of human intrusion scenarios that could be contemplated, nor does it intend for this analysis to address the full l
range of possible intrusions that could occur. Rather, the Commission intends that this analysis l show that the repository exhibits some resilience to a breach of engineered and geologic barriers from events that are reasonably of concern. Therefore, the Commission is proposing an assumed human intrusion scenar:o that results in the breach of both engineered and geologic barriers. The Commission believes that current practices provide a solid basis for establishing properties for the intrusion scenano that avoid speculation Therefore the 44
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Commission is proposing that DOE use current practices for resource exploration to establish properties (e g., diameter of the borehole, dnlling rate, composition of dritiing fluids) for the intrusion scenario. However, because the Commission intends for this analysis to show that i N L the repository can still g
L l . adequately perform if its barriers are breached, the Commission is requiring DOE to assume that the borehole is not adequately sealed to prevent infiltrating water.
Elsewhere in its regulations (e.g.,10 CFR Part 60), the Commission has limited the extent to which reliance may be placed on active institutional controls to prevent unacceptable radiological exposures from the disposal of other radioactive wastes. Consistent with this approach the Commission is proposing that the intrusion scenano be assumed te occur 100 years after repository closure.
. The Commission is mindful that a single stylized intrusion scenario should not be taken as a prediction of the likely manner or frequency of intrusion. As NAS stated in its report, a
' calculation of consequences for such an intrusion removes from consideration a number of !
imponderables, each of which would otherwise need to be treated separately, including the probability that an intrusion borehole would intersect a waste canister, the probabilities of detection and remediation, and the effectiveness of institutional controls and markers to prevent
~ intrusion. This scenario should not be interpreted as either an optimistic or pessimistic estimate of what'might actually occur...We believe that the simplest scenario that provides a measure of the ability of the repository to isolate waste and thereby protect the public is the most I.
appropriate scenario to use for this purpose."
I Beanng this in mind, the Commission solicits comment on the appropriateness of its 7
proposed intrusion scenano,' and the assumed timing of its occurrence, as a reasonable l
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i measure for evaluating the consequences of intrusion at a repository at Yucca Mountain. i i
Xil. Preclosure Performance Objective :
)
l The Commission is proposing performance objectives at 63.111 to ensure that the geologic repository operations area is designed and operated to protect against radiation !
l exposures and releases of radioactivity prior to permanent closure. Specifically, protection of I
the worker and general public is ensured by requiring that 1) the exposure limits codified at I
10 CFR Part 20 are maintained. and 2) during normal operations and anticipated operational occurrences, the annual dose to any real member of the public, located beyond the boundary of l the site, shall not exceed a TEDE of 0.25 mSv (25 mrem). The 0.25 mSv (25 mrem) limit was included to provide consistency with requirements for the MRS and other waste management facilities (e.g.,40 CFR 191.03(a),10 CFR 72.104, and 10 CFR 61.40). Additionally, numencal guides for design objectives have been specified for Category 1 design basis events and Category 2 design basis events. Category 1 design basis events are those events that are expected to occur one or more times before permanent closure. Included in Category 1 design i basis events are event hat occur regularly or moderately frequently, and that are sometimes identified as " normal operations" associated with receiving, handling, packaging, stonng, emplacing, and retrieving high-level waste. Also included in Category 1 design basis events
't- are those event that occur one or more times during the operating lifetime of a facility, and that are sometimes identified as " anticipated operational occurrences" or " accidents."
Category 2 design basis events are those events that have at least one chance in 10.000 of occurring before permanent closure. For an operational penod of 100 years. this corresponds I
4 Category 2 design basis events are unlikely, but to an annual probability of occurrence of 10 46
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specified in S 63.111. As used here, integrated means joint consideration of safety measures 1
that, considered separately, might not achieve the overall health and safety protection desired. l Such integration would include, but not be limited to, integration of fire protection, radiation safety, criticality safety, and chemical safety measures.
A fundamental aspect of the ISA is the identification and analysis of Category 1 and l Category 2 design basis events. Category 1 events as described above represent " normal operations" while Category 2 events represent unlikely but credible events which would challenge the design of the GROA to maintain exposures within allowable limits. The analysis ;
of a specific Category 2 design basis event would include an initiating event (e.g., an earthquake) and the associated combinations of repository system or component failures that can potentially lead to exposure of individuals to radiation. An example design basis event is a l postulated earthquake (the initiating event) which results in (1) the failure of a crane lifting a spent fuel waste package inside a waste handling building, (2) damage to the building ventilation (filtration) system, (3) the drop and breach of the waste package, (4) damage to the spent fuel, (5) partitioning of a fraction of the radionuclide inventory to the building atmosphere, (6) release of some radioactive matenal through the damaged ventilation (filtration) system, and (7) exposure of an individual (either a worker or a member of the public) to the released radioactive matenal.
The Commission believes the proposed approach, which does not include specification of general design criteria, is appropnate because presenptive design entena may unnecessarily encumber DOE, given the ongoing nature of site characterization of the underground facility and evolution of facility design. The information the Commission needs to make a finding of
- reasonable assurance that the GROA will inbe" comply witrequirements reclosure 1 the risk-bessd@
at 63.111, will be provided by the ISA The Commission proposes enteria, at @ 63.112. for the 48
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l content of the ISA.
XIV. Quality Assurance l
As is currently required by the generic cnteria at 10 CFR Part 60, the Commission is proposing that DOE implement a quality assurance program, for the geologic repository, based 1
on the critena of Appendix B of 10 CFR Part 50. Although an essentially equivalent quality assurance program for the independent storage of spent nuclear fuel and HLW is specified at I Subpart G of 10 CFR Part 72, the Commission believes it to be appropnate to continue to reference Appendix B for the geologic repository at Yucca Mountain for purposes of maintaining continuity between data collected. dunng site charactenzation, pursuant to Part 60 requirements and those that will be collected once Part 63 requirements take effect. The Commission is seeking comment on the ments of this approach.
XV. Emergency Planning When the Commission published final generic criteria for geologic disposal in 1983, licensing requirements for emergency planning were reserved for a later date. On June 22, 1985 (60 FR 32430), the Commission published final amendments to 10 CFR Part 72 that codified generic emergency planning licensing requirements for independent spent fuel storage installations (ISFSis) and monitored retrievable storage facilities (MRS). These amendments l
provided for enhanced requirements for offsite emergency planning at MRS facilities (as v.all as at any ISFSis that conductf similar operations) because of the broader scope of activities that ,
could be performed at these facilities relative to those conducted at simpler storage 49
$ 63.1 Purpose and scope.
This part prescribes rules governing the licensing of the U.S. Department of Energy to receive and possess source, special nuclear, and byproduct material at a geologic repository operations area sited, constructed, or operated at Yucca Mountain. Nevada, in accordance with the Nuclear Waste Policy Act of 1982, as amended, and the Energy Policy Act of 1992. As Mie provided in S 60.1, " Purpose and scope " the regulations in Part 60 of this M.do not apply 3
to any activity that is subject to licensing under this part. This part does not apply to any activity licensed under another part of this chapter. This part also gives notice to all persons who knowingly provide, to any licensee, applicant, contractor, or subcontractor, components, equipment, materials, or other goods or services, that relate to a licensee's or applicant's activities subject to this part, that they may be individually subject to NRC enforcement action for violation of 9 63.11.
9 63.2 Definitions.
As used in this part:
Affected indian Tribe means any Indian Tribe: (1) within whose reservation boundaries a repository for high-level radioactive waste or spent fuelis proposed to be located; or (2) whose Federally defined possessory or usage rights to other lands outside of the reservation's boundaries arising out of Congressionally ratified treaties or other Federallaw may be substantially and adversely affected by the locating of such a facility; Provided, that the Secretary of the Interior finds, on the petition of the appropriate governmental officials of the Tribe, that such effects are both substantial and adverse to the Tribe i.
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D Annual dose means the total effective dose equivalent (TEDE as defined at S 20.1003) received in a single year by the average member of the critical group as a result of, radioactive A materials released from the geologic repository.
Barrier means any material or structure that prevents or substantially delays movement of water or radioactive materials. ,
Commencement of construction means cleanng of land, surface or subsurface excavation, or other substantial action that would adversely affect the environment of a site. It does not include changes desirable for the temporary use of the land for public recreational uses, site charactenzation activities, other preconstruction monitoring and investigation necessary to establish background information related to the suitability of the Yucca Mountain site or to the protection of environmental values, or procurement or manufacture of components of the geologic repository operations area.
Commission means the Nuclear Regulatory Commission or its duly authorized I representatives.
Containment means the confinement of radioactive waste within a designated boundary.
Cntical group means the hypothetical group of individuals reasonably expected to receive the greatest exposure to radioactive materials released from the geologic repository.
Design bases means that information that identifies the specific functions to be performed by a structure, system, or component of a facility and the specific values or ranges of values chosen for controlling parameters as reference bounds for design. These values may be restraints derived from generally accepted " state-of-the-art
- practices for achieving functional goals or requirements derived from analysis (based on calculation or expenments) of the effects of a postulated event under which a structure, systeri or component must meet its functional goals. The values for controlling parameters for ext'rnal events include:
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., l (xiii) Means to inspect, test, and maintain structures, systems, and components important to safety, as necessary, to ensure their continued functioning and readiness.
(6) A description and discussion of the design, both surface and subsurface, of the geologic repository operations area, including:
(i) The relationship between pnncipal design enteria and the requirements specified at
@ 63.111(a) and (b); and (ii) The design bases and their relation to the principal design enteria.
l 9 63.113 Performance objective for the geologic repository after permanent closure.
(a) The geologic repository shallinclude multiple barriers, consisting of both natural barners and an engineered barrier system. .
(b) The engineered barrier system shall be designed so that, working in combination with natural barners, the expected annual dose to the average member of the entical group shall not exceed 0.25 mSv (25 mrem) TEDE at any time during the first 10.000 years after ,
permanent closure, as a result of radioactive matenals released from the geologic repository.
(c) The ability of the geologic repository to limit radiological exposures to those
$ specified in paragraph (b)shall be demonstrated through a performance assessment that meets the requirements specified at @ 63.114, uses the reference biosphere and cntical group specified at @ 63.115, and excludes the effects of human intrusion.
(d) The ability of the geologic repository to limit radiological exposures to those 4 specified in paragrap(b in the event of limited human intrusion into the engineered barner I
system, shall be demonstrated through a separate performance assessment that meets the requirements specified at @ 63114 and uses the reference biosphere and critical group specified at @ 63.115. For the assessment required by this paragraph, it shall be assumed tnat 148
9 4 J
NRC PROPOSES CHANGES TO REGULATIONS FOR LICENSING t i
PROPOSED RADIOACTIVE WASTE REPOSITORY IN NEVADA L The Nuclear Regulatory Commission is proposing to revise its regulations to add site-specific cntena for licensing a proposed geologic repository at Yucca Mountain, Nevada, for the l disposal of spent nuclear fuel and high-level radioactive wastes.
l The criteria, which are being issued for public comment, would be contained in a new l Part 63 of the Commission's regulations.
A different part of the Commission's regulations, Part 60, issued in 1983, contains enteria l for licensing the disposal of spent fuel and high-level radioactive wastes in_itny n geologic repository. The NRC proposes to modify that regulation to make clear that it no longer applies to 1
a repository at Yucca Mountain. f (eg t hich directed the i The proposed changes are in response to the Energy Policy Ac NRC to modify its technical requirements and entena to be consistent with health and safety l standards to be issued by the Environmental Protection Agency (EPA) specifically for Yucca N M d ue_ h h no.J nu l-t n A e m w J+u N. N hs M qs e ' o v~MlifA*
i Mountain.
/(Yh %s y.+ h cMty e.d % s k t eL%A The E A standards re to be based on 1995 recommendations of the National Academy s
of Science The Act als directed NRC to make its modifications within one year after issuance of final EPA standards. To meet this schedule, NRC must develop regulations containing the modified criteria in parallel with EPA's development of standards.
Therefore, the NRC is proposing new site-specific criteria for the proposed repository that it believes are consistent with the requirements of the Energy Policy Act an'd the Nuclear Waste Policy Act. The NRC recognizes that when EP.A issues its final standards. NRC's s
proposed regulations may need to be amended. or if eu euch hn&) itLW l 1,i.h m
,o h w ~
. The proposed new regulations specify that the repository system at Yucca Mountain l
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2 l must include both natural and engineered barriers to the release of radioactive material. They also address licensing procedures, enteria for public participation, record and reporting, monitoring and testing programs, performance confirmation, quality assurance, personnel l training and certification, and emergency planning.
The performance objectives for the repository would include these provisions:
(1) After high-level waste has been placed in the repository and the facility has been e(perf ed C permanently closed, the[Jnnual radiation dose to the average member of the " critical group" fro i
the radioactive material would not exceed 25 millirems per year. (Critical group is defined as the j hypothetical group of individuals expected to receive the greatest expocure to radioactive 7-t'.'ll f a q s y materials released from the repository.) The 25-millirem' limit may be compared to the i e Commission's overall annual pubhc dose limit of 100 millirems. I ' d ' MI "U Mp m ,alu % dvw Mk A sw kw -ik (2) The repository's engineered barrier system, working in combination with natural 7 o p s ed 4.Q l A
bamers, would prevent the 25-millirenfannual dose limit from being exceeded at a the first 10,000 years after permanent closure.
(3) Active and passive controls would reduce the potential for inadvertent human intrusion into the site. If those controls failed 100 years after permanent closure, and someone drilled a single, nearly vertical borehole into the repository and penetrated the waste packa ,
op4e6 y the 25-milllirem nnual dose limit would not be exceeded dd*' b 3,,b.a,"<l] tone _,
(4) During normal repository operations, before permanent closure, radiation exposures le bd d v b l
K to members of the publi would not exceed illirems. 25 r)c4 N M t bah)
In addition, the proposed regulations would preserve the option for retneving waste on a reasonable schedule starting at any time up to 50 years after waste emplacement begins, unless a different time penod is approved by the Commission.
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.paCecg J*, UNITED STATES ;
a o NUCLEAR REGULATORY COMMISSION O I WASENGTON, D.C. ""1
% # es (heJ dic k led. $ 1h ht htW e A
% h L ,<ew<*% ^ } , E The Honorable Dan Schaefer, Chairman ,% 1 Subcommittee on Energy and Power Committee on Commerce United States House of bM"') dA
Representatives %A pi,pb . ,
l Washington, DC 20515 l
Dear Mr. Chairman:
The U.S. Nuclear Regulatory Commission intends to publish the enclosed proposed l
amendments to the Commission's rules in the FederalReaister, shortly. The proposed i amendments would establish risk-informed, performance-based criteria for the disposal of high-level radioactive waste at the proposed geologic repository at Yucca Mountain, Nevada.
The Commission was directed by the Energy Policy Act of 1992 (Public Law 102-486) to modify its technical cnteria, as necessary, to be consistent with health and safety standards, for Yucca Mountain, that are to be issued by the U. S. Environmental Protection Agency (EPA) pursuant to ,
the same statute. According to the Act, these standards are to presenbe the maximum annual l effective dose to individual members of the public; are to be based on and consistent with, recommendations of the National Academy of Sciences (NAS), issued in 1995; and are to be the only standards applicable to Yucca Mountain. NRC is continuing to work with EPA in the development of reasonable and implergentable standards for Yucca Mountain that are protective of the public health and safety. NeveGhq[ess, the Commission believes that it has an X obligation to make public how it would implement the dose-based standards required under the Energy Policy Act, and believes that it must move forward in developing its own regulations so as not to delay the Nation's repository program. The proposed NRC regulations are generally consistent with the risk limits recommended by the NAS, international standards, and NRC regulations for other waste management facilities. Furthermore, the Commission believes that its proposed approach ensures protection of public health and safety and provides appropriate flexibility to DOE for demonstrating compliance, while ensuring that the information required to make a licensing decision will be provided to the Commission.
Sincerely, l Dennis K. Rathbun, Director Office of Congressional Affairs l
t l
Enclosure:
Federal Reaister Notice cc: Representative Ralph Hall