ML20217A595
| ML20217A595 | |
| Person / Time | |
|---|---|
| Issue date: | 10/02/1997 |
| From: | Advisory Committee on Reactor Safeguards |
| To: | Advisory Committee on Reactor Safeguards |
| References | |
| ACRS-3075, NUDOCS 9803250137 | |
| Download: ML20217A595 (13) | |
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1, R. L.Seale, Chairman October 3, 1997 o
CdAS-3675 October 2, 1997
SUMMARY
/ MINUTES OF THE ACRS PLANNING AND PROCEDURES SUBCOMMITTEE MEETING OCTOBER 1, 1997 The ACRS Subcommittee on Planning and Procedures held a meeting on October 1, 1997, in Room 2B1, Two White Flint North, Rockville, Maryland.
The purpose of the meeting was to discuss matters related to the conduct of ACRS business.
The meeting was convened at 10:30 A.M. and adjourned at 12:00 noon.
ATTENDEES R. L. Seale, Chairman D. A. Powers T. S. Kress ACRS Staff J. T. Larkins, ACRS Executive Director S. Duraiswamy C. Harris R. Summers J. Sorensen, ACRS Fellow (part time) f J. Mitchell, NRC Staff j
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1.
Annointment of New Members (Open) jo/
The Commission, in a May 6, 1997 SRM, requested the Screening Panel to recommend additional candidates for consideration by the Commission for appointment to the ACRS.
The candidates were to have expertise in the areas of thermal hydraulics / computational fluid dynamics and nuclear power plant operations.
A memorandum recommending three I
additional candidates with expertise in thermal hydraulics / computational fluid dynamics was sent to the Commissign on September 30, 1997.
The Screening Panel is still seeking qualified candidates with expertise in the 9803250137 971002
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cron of nuclecr plcnt oparations and expacto to provida a list of candidates to the Commission in the near future.
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2.
.Mmeting with Individual commissioners (Open)
Commissioner Dieus is scheduled to meet with the Committee during the December ACRS meeting, and we have tentatively scheduled a meeting with the Chairman during the November ACRS meeting.
Commissioner Diaz was.previously scheduled to meet with the Committee in December.
He has canceled that meeting.
We plan to schedule a meeting with Commissioner Diaz during the February ACRS meeting.
Dr. Larkins met with the NRC Chairman on September 19, 1997 and will brief the Committee on issues discussed with the Chairman.
4 3.
AENW Renort on Defense-in-Denth (Open)
The ACNW met on September 23-25, 1997, to discuss defense-in-depth (DID) principles, and drafted a report (pp.1-7) to the Commission proposing that DID be employed in the licensing of a high-level waste. repoeitory.
The ACNW plans to continue its discussion of this report during its October 21-23, 1997 meeting.
Dr. Larkins attended this meeting and will brief the subcommittee.
Recommendation The Subcommittee recommends that the members review the attached ACNW draft report and provide comments to Dr.
Larkins by October 15, 1997.
4.
Proposed Rulemakine on shutdown and Fuel Storage Pool Operatinna (Open)
We have received a September 19, 1997 memorandum from the EDO to Chairman Jackscn (pp. 8-50) which provides staff responses to issues related to this proposed rulemak1ng identified by Chairman Jackson and Commissioner Diaz. The members should review the above-mentioned document in preparation for meeting with the Chairman in November.
Recommendation The Subcommittee recommends that members review this i
document and subsequent correspondence from the EDO in M
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, preparation for the meeting with the Chairman in November.
5.
Operatina plan (open)
Operating Plans are being developed for all of the NRC offices.as required-by the Government Performance and Results Act.
The ACRS/ACNW Operating Plan is being prepared and the schedule for submitting this plan is October 10, 1997.
I We are anticipating that the Operating Plan will replace the requirement for an ACRS/ACNW Performance Report.
A memorandum was forwarded to the Commission making this request.
Recommendation The Subcommittee recommends that all members receive a copy
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of the Operating Plan when it is completed.
1 6.
status of Meetinos with Representatives of Foreien Countring (open)
R.
Summers received a reminder from the German RSK Committee for the ACRS to pay a return visit to Germany in 1998.
R. Summers replied that a visit may not be possible in 1998.
On September 26, 1997, Prof.
Birkhofer forwarded a fax'to Dr. Larkins, ACRS Executive Director, stating that he had talked with Pir. Sato, Vice-Chairman of the Japanese Safety Committee, rand that we should anticipate a response shortly from the Japanese on the Quadripartite Maeting.
Recommendation The Subcommittee recommends that the ACRS no longer consider the possibility of holding a Quadripartite Meeting in Japan in January 1998 but to further consider the possibility of a meeting with the RSK Committee in Germany and/or the Committee for the Safety of Nuclear Installations (U.K.)
in 1998.
Dr. Kress and Dr. Powers will prepare a list of 1
.possible topics for these two proposed meetings for discussion at the next Planning and Procedures Subcommittee 1
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' meeting.
7.
ACRE Pull comm4 tree Meeting Dates for 1998 (Open)
'A calendar of meeting dates has been distributed with a request for member comments by september 26, 1997.
No comments on the proposed meeting dates have been received; therefore this schedule is considered final with the exception noted below.
One additional meeting should be scheduled in the February / March time frame to review the NRC
-Safety Research Program and provide comments to the Commission.. We suggest that the 450th meeting be scheduled for March 2-4, 1998, to discuss the NRC Safety Research Program, just prior to the 451st ACRS meeting on March 5-7,
1998.
j Recommendation I
The subcommittee recommends that the additional meeting to discuss the NRC Safety Research Program be scheduled'for March 2-4, 1998.
8.
Status of ACRE /NRC Staff Interaction on the safety Immuna Ammoeinted with the Une of High-Burnun Fuel (Open)
The Reactor Fuels Onsite Fuel Storage and Decommissioning subcommittee scheduled a meeting on October 9, 1997 to discuss-the safety issues associated with the use of high-burnup fuel.
The NRC staff, however, was unable to support the meeting and requested an additional two months to respond to the Subcommittee's concerns.
Dr. Powers is concerned that these continued delays will significantly impact on the. Committee's ability to advise the commission on this important subject.
It shon1d be noted that, as' a result. of the subcommittee
-discussions, staff was able to focus on and initiate its review of:the safety issues related to the use of high-
.burnup fuel in commercial light water reactors.
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Recommendation h
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JThe Subcommittee recommends that a meeting of the Reactor Fuels, Onsite Fuel Storage and Decommissioning Subcommittee meeting be held in December 1997 and that a briefing for the full Committee be scheduled for the February 1998 full Committee meeting.
9.
Anticipated AERE Activities Related to the Review of the AP-soo nemian (open)
Dr. Powers is concerned as to the impact of these activities on ACRS workload and the need to plan.
Proposed schedule for ACRS review of the AP600 design is attached (p.
51).
Recommendation i
The Subcommittee recommends that interim reports be issued as ACRS partial, reviews of the design are completed, rather than waiting until the conclusion of the review to issue one final report.
10.
Member Tamune (Open)
One travel request was received for Dr. Fontana to attend the ANS meeting in Albuquerque on November 16-20, 1997 (p.52).
The ACRS retreat is scheduled for January 30-31, 1998 at Lansdowne Resort in northern Virginia.
Recommendation The Subcommittee recommends that the travel request for Dr.
Fontana be approved.
The Subcommittee recommends that members confirm their availability for the Retreat so that arrangements can be finalized.
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1 September 30,1997 Note to:
ACNW Members T
4D FROM:
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SUBJECT:
DRAFT 4 OF 'A RECOMMENDED APPROACH TO IMPLEMENT THE DEFENSE-IN-DEPTH CONCEPT IN THE REVISED 10 CFR 60" Enclosed for your review is a copy of the subject letter. This draft reflects the changes made during the meeting in Las Vegas. If you have additional thoughts, please provide them to George or me by October 10,1997. Thank you.
Enclosure:
As Stated cc:
J. Larkins R. Savio ACNW staff i
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The Honorable Shirley Annlackson 1
U.S. Nuclear Regulatory C==ission
- Washington, DC 20555-0001
Dear ChairmanJackson:
SUBJECT:
A RECOMMENDED APPROACH TO IMPLEMENT THE DEFENSE-IN-DEP1H CONCEPT IN DIE REVISED 10 CFR PART 60 This letter communicates the ACNW's ramenmandarians for adopting a revised approach to 1
existing subsystem performance criteria in 10 CPR Part 60 to implement the defense in-d 2
(DID) concept This letter is one in a series ofletters to the NRC Chairman conveying the 3
ACNW's views on aspects of the NRC staffs strategy for revising 10 CFR Part 60. Previous 4
letters on the staffs strategy for revising 10 CFR Part 60 include " Issues and NRC Activities 5
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A* Hated with the National Research Council's Report, Technical Bases for Yucca Mountain 6
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Standards'," February 9,1996, ' Time Span for C= phae
- of the Proposed High-I.evel Waste 1
s Repository at Yucca Mm=*=ia Nevada," June 7,1996, and the ' Reference Biosphere and Critical Group Issues and Their Application to the Proposed HLW Repository at Yucca Mountain, i
9 Nevada," Apri! 3,1997. Our recommendations are formal +M on the basis ofpresentations ma 10 to the Connaittes during the 90th, 91st, 92nd, and 93rd meetings fkom the NRC stafE the DOE 11 staff and its contractors, the State ofNevada, the National Research Ce='1. and repr==antat 12 from industry, as well as the C==taaton's policy on risk-informed, performadased regulat 13 34 15 4
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15. In this letter the concept cf ' defense in depth" refers to the methods cf design, construction and 17 geological repository for HLW in ways that aim to ensure safety in the face of considerable
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!s ' uncertainty in our knowledge ofvarious processes. The application orimplementation of DID in g
the repository context entails an analysis that exposes the contribution of each design element, 9
20 each process (or set of processes) in the natural geological setting, and each operational technique at to the safety of the repository. The DID concept embodies the notion ofmultiple barriers that act 22 to isolate the waste. One of the nWorissues regei4 regulation within the DID framework is 23 whether and how prescriptive requirements (so called subsystem requirements) abould be placed 24 on classes of these barriers.
25 26 The Nuclear Waste Policy Act of1982, as amended, mandates NRC to develop technical criteria
-27 for high-level waste (HLW) disposal that are consistent with the EPA generic standards and 2s provide for a system ofmuhiple barriers. He Energy Policy Act of 1992 mandates NRC to 29 conform its regulation to the fins! EPA standards for Yucca Mountain, the latter of which are to I
J be based on and consistent with recommendations made by the National Academy of Sciences u. Committee on Technical Bases for Yucca Mountain Standards (TBYMS). As directed by the 32 Commission, the NRC staffis presently pursuing development of site-specific regulations for 33 Yucca Mountain to implement the forthcoming EPA site-speci5c standards for Yucca Mountain.
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35 The present form of 10 CFR Part 60 partly implements the DID approach by prescribing l
36 performance requirements of"particular barriers". As noted in the Statement of Considerations 37 (SOC) to 10 CFR Part 60, this multiple banier approach identifies two engineered baniers; the 3:
waste package, and the underground facility, in addition to the naturs! barrier provided by the
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39'. geologic setting. The SOC cotes that the multiple harder concept is implemented by the t.
40 performance objectives or requirements as well as by more detailed siting and design criteria.
41 The Committee recognizes that inclusion of the ;'='*haWe subsystem performance requirements g
1 in the rule was intended to provide additional con 5dence to sg=we for uncertainties 43 associated with prMag the behavior of a repository over th===ade ofyears, and for NRC's lack of experience and con 6dence in analyzing repository performance. The Commhta= believes 44 45 the adoption of a risk-informed approach eliminates the need for sped 5 cation of subsystem 46 requirements for Yucca Mountain.
47 4s Having both engir.eering and geology contribute to waste isolation is a reasonable regulatory goal 49 for providing reasonable assurance offepository safety overlong time spans. That is, the 50 Committee realizes the need for muhipit barriers within the DID wecept. However, we do not l
si endorse the implementation of the DID concept via inclusion ofpi.dpuve subsystem criteria.
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- 2 The DID concept has been a fundamental tenet ofregulatory practice since nuclear licensing I
began. It is a sound concept r,w ty supported over the years by the ACNW. Thus, the issue is
._s4 not the validity of the concept ofDI, but rather.how the.:encept abould be implernented...
55 56 A major problem with the current version of10 CFR60.113 is that it is not clearjust how relevant 57 any subsystem performance requirement is to the overall safety performance of the repository.
5 The connection between barrier performance and overa!! performance is very site-and design-59 speci5c. Prw?4 individual barrier p.Tv.w.escs may create a design imhalaarmd in terms of i
l 60 individual barrier effectiveness and =&*=hL1hy. Subsystem requirements may also result in l
61 very poor designs tom an economic F==-t-?^ The ACNW's viewis consistent with the l
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{,,., 61 - TBYMS, which cautioned against knposing subsystem repw.s that may inadvertently r 63 in a suboptimalrepository design.
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a 5 JtECOMMENDATIONS 66 1.
The Cc' mnittee endorses the concept of defense in depth, particularly in' regard to the use ofnadtiple barriers ofpr-M but reco==n=le changes in the application of the 67 es e-*. The Committee roccannends that sound principles be set forth ; Mag the 69 implementation of the concept of defense in depth.
70 71 We believe that guidance will depend to a large extent on proper construction 'of a PA to 72 expose the role of design elements, operati,onal elements, and mukiple barriers.
The 73 regulations should be clear on how the defense-in-depth concept should be implemented.
74 The Committee recommends that an overall perfonnance standard that directly relates to
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15 the safety of the public be set. Iicense applicants should be directed to fbrnish I
6 documentation that shows how the DID W has been implemented in meeting the 77 overall perfornunce goal. The Commines realizes that crafting guidance to the license applicant on " nplementation ofDID is a critical task that we do not fbily detail here. The 7s u
79 Committee plans to consider these issues in the fbture.
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The Commines recommends that the need for qu J/c4 the effectiveness ofindividual s2 barriers in relation to implementing DID be a prime consideration in the NRC stafPs hrmance asamnenwr* capability.
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The performance assessment should clearly expose the effeedveness and r;;1e cfselected
,s e6 individual barriers such as the engineered systems and the natural geologic setting. The s7 '
' assessmem ofirsdividual barriers should include a quanti 5 cation of the uncetainties
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w involved. The Committee believes that there are methods for quantifying the role of s9 individual aapad barriers ifuncertainty analysis is employed and there are methods of 90 assessing the contaiarnant capacity of the natural seedng and therefore its depaaA-on 91 engineered systems to meet performance goals. To achieve the capability to assess the 92 affectiveness of individual barriers, geologic and engineered, it may be nar=mry to 93 modify the analysis methods, including the PA models, and to enhance the database to 94 better expose the performance ofindividual barriers.
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SUMMARY
97 The ACNW believes that the level of uncertainty associated with the safe disposal ofHLW in
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9 Yucca Mountain warrants the continued implementation of the defense-in-depth (DID) wisept of
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7 regulation. The Committee believes that the regulations should not specify r=a*=4e subsystem 100 requirements, but we.strongly believe that there should be multiple baniers ofprotection and that 101 guidance to the license applicant should state that the contribution of each barrier (both geological 102 and engineered) should be quantified (measured) in terms ofits importance to meeting an overall los standard ofperformance. The method ofmeasurement should be supported by a set ofprinciples los and analyses, bued on chemical and physical phenomena, that clearly expose the models and the los supporting information and data. In this regard it is vad hat performance assessment and t
los the lessons learned th.
, W Hy about physical process modeling, should be a major tool 107 in providing this measursment.
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4-losi.The Committee believes the approach recommended by the C-mittee effers many advantages 13 over prescriptive subsystem requirements. First, h allows taking mavimum advantage of site-and y
11o design-specific pregrJes and features. Second, it is a clear example ofrisk informed,
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performance-based regulation. The important contnhators to risk can be ranked, thus providing a.
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112 basis for prioritizing corrective actions and risk management activities. Third, it reduces the q
113 mystery of the dependence of overall repository performance on individual barriers. In a sense, the safety margins of the various baniers are made more explicit through quantification.
114 115 116 g,
117 Ils B. John Garrick
. 33'
_... _. Chairman
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-1 Upd(ited:9-29-97
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AP600 DESIGN REVIEW SUBCOMMITTEE MEETINGS PLANNED ACTIVITIES 12/9-10/97 Thermal Hydraulic Phenomena:
PIRT: Scaling of RCS: 'NOTRUMP Code i
f 12/11-12/97 Thermal Hydraulic Phenomena: WGOTHIC Primary Coolant System Code 2/4/98 Advanced Reactor Designs:
Chap. 6: Engineered Safety Features [3.0]
Chap. 7: Instrumentation and Controls [2.0]
Chap. 8: Electrical Power [1.0]
Chap. 10: Steam and Power Conversion System [1.5]
Chap. 18: Human Factors Engineering [2.0]
4/1/98 Advanced Reactor Designs:
Chap. 9: Auxiliary ystems [2.0]
Chap. 12: Radiation rotection [1.5]
' Chap. 13: Conduct of Operations [1.5]
Chap.16: Technical Specifications [1.0]
Chap. 17: Quality Assurance [1.5]
5/13-14/98 Advanced Reactor Designs:
Chap. - 2: Site Characteristics [1.0]
Chap. 3: Design of Structures. Comp., Equip., and Systems [1.0]
Chap. 14: Initial Test Program [1.0]
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Chap. 15: Accident Analyses [3.0)
Probabilistic Risk Assessment [3.0]
ITAAC [2.0]
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RTNSS [2.0) 6/10/98 Staff Issues FSER The f 3110 wino meetinos will be held a s needed to comoete the desian review.
-7/7/90 Acvanced Reactor Designs:
Review FSER Chapters 1-5 9/1/98 Advanced Reactor Designs: Review FSER Chapters 6-10 9/2/98 Advanced Reactor Designs: Review FSER Chapters 11-15 9/29-30/98 Advanced Reactor Designs: Review FSER Chapters 16-18 and Probtbilistic Risk Assessment 10/1/98 Full Committee: Review FSER and write letter 10/1/98 Full Comittee: Issue letter 11/ /98-Comission approval 11/ /98 Staff. issues Final Design Approval 'and Federal Register Notice e
Westinghouse submits Design Certification Document Staff, issues Design Certification y
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