NRC Generic Letter 1988-02
- a REeGUNITED SPATESA SNUCLEAR REGULATORY COMMISSIONWASHINGTON. 0. C. 20555January 20, .1988TO ALL POWER REACTOR LICENSEESGentlemen:Subject: Integrated Safety Assessment Program II (ISAP II)(Generic Letter 88-02)The Integrated Safety Assessment Program (ISAP) was a pilot program initiatedir May 1985 for Millstone Unit 1 and Haddam Neck. The program was designed toPiV provide a comprehensive review for operating reactors to address all safety4 Issues and to provide an integrated cost-effective implementation plan usingdeterministic and probabilistic techniques. ISAP also provided the technicalbases to resolve all outstanding licensing actions, established overall plantImprovement schedules, and served as a benchmark from which future regulatoryactions could be judged on a plant-specific basis. ISAP Is described in a pol-icy statement published in the Federal Register on November 15, 1984 (49 FR 45112)-and in Generic Letter 85-07.On November 4, 1987, the staff briefed the Commission on the status and resultsof ISAP and made recommendations for future activities relating to that program.At that meeting the staff recommended that the benefits of the ISAP approach bemade available to all licensees. Identified benefits of the ISAP program include(1) finding common elements in separate review areas and proposing a single inte-grated action to resolve the concerns, (2) addressing pending requirements on aplant-specific basis, and (3) dropping issues from further consideration becauseof low safety significance. The Commission deferred action on extending the ISAPconcept beyond the pilot program and, among other things, asked the staff to de-termine the industry's Interest in such a program. Accordingly, the staff isissuing this generic letter to describe ISAP II, a derivative of ISAP, and toascertain utility interest in participating in this proposed program.ISAP II Is a disciplined program to address regulatory issues within an integratedschedule based on two analytical tools: probabilistic risk assessment (PRA) andoperating experience review. The operating experience review will determine sys-tematic weaknesses and trends as well as provide actual historical plant operatinginformation against which to judge the reasonableness of PRA findings. An inte-grated assessment based on the two analytical tools will determine the rankingof issues from which the integrated schedule will be developed. The integratedschedule will allow regulatory issues and utility-initiated items to be priori-tized and scheduled within the framework of all scheduled items.ISAP II is designed to accomplish the same objectives as ISAP with certain pro-grammatic differences. Unlike ISAP, ISAP II would not again review issues againstcurrent Standard Review Plan sections. Therefore, incorporating lessons learnedfrom the Systematic Evaluation Program (SEP) would not be a requirement forparticipants in ISAP II as it was in ISAP. ISAP II would only include currentand future items for a plant. In addition, ISAP II participants would not beexpected to address unresolved generic issues ahead of the staff's generic reso-lution. Through the ISAP II process, it may be determined that certain issues(Zvoo21033 X'Z P 2§D b-60-6 Ky-2 --can be combined and resolved concurrently or that certain issues have a low safetysignificance, which would make them candidates for a lower priority or for beingdropped. Enclosure 1 provides additional details regarding ISAP II.An important advantage of ISAP II is that its minimum-required Level 1 PRA ccm-bined with a containment vulnerability assessment (or a Level 2 or Level 3 PRA)constitutes an acceptable method for a utility to perform its Individual PlantExamination (IPE). This examination is the means of satisfying certain require-ments of the Commission's Severe Accident Policy Statement, which was publishedin the FederLlRegister on August 9, 1985 (50 FR 32138). Therefore, by perform-ing a PRA for ISAP II, the licensee would have made substantial progress toward -completing its IPE.Benefits to those licensees participating in ISAP II include:o The integrated schedules for the ISAP II implementation of issues will providea predictable safety basis for the staff and licensee to manage current work-loads and to estimate the resources necessary to meet future requirements.Required resources are expected to be reduced in the long run by combiningissues and eliminating low safety significant issues.o Licensing and generic issues are treated on a plant-specific basis and areweighed against'all other pending actions. Through the ISAP II process,the licensee will have an opportunity to demonstrate, by using its PRA,that various generic issues are not justified at its facility on the basisof the safety significance of the issue.o Safety will be enhanced and the safety value for each dollar spent will beincreased because issues of highest safety significance will generally beworked on first.* ISAP II is a process that may form part of the basis to consider plant lifeextension requests and plant aging issues.o Bases for optimization of maintenance/surveillance intervals may be derivedfrom ISAP II. For example, a PRA analysis provided a basis for increasedsurveillance intervals and out-of-service times for Westinghouse reactor tripsystem maintenance and surveillance frequencies.o The process will help improve outage planning by providing a longer termoutlook of modifications for the upcoming outages. This could reduce outagedelays.o Participation in ISAP II will involve the licensee in a detailed PRP leadingto an enhanced understanding of plant capabilities for both it and the NRC.The ISAP II process will improve the interface between licensee engineeringand plant operations by fostering communications in areas of mutual respon-sibility addressed in the performance of a plant-specific PRA.I
-3-The staff wants to identify participants for ISAP II starting in 1988. Poten-tial interest will be assessed on the basis of utility response to the survey ofEnclosure 2. We request your response, indicating positive or negative Interestin participating, within 30 days of the date of this letter so that the staffmay meet its commitment to the Commission to evaluate industry interest by March1988. An expression of interest will not be construed as a licensee commitmentto participate. Since the staff is not seeking a particular cross-section ofplants or utilities, it will determine the participants through further communi-cation with those utilities expressing interest.If you have questions regarding the information discussed in this genericletter, contact Melanie Miller at (301) 492-1281.This request is covered by Office of Management and Budget Clearance Number3150-0011 which expires December 31, 19C9. Comments on burden and duplicationmay be directed to the Office of Management and Budget, Room 3208, NewExecutive Office Building, Washington, D. C. 20503.Frank ciate Directorfor ProjectsOffice of Nuclear Reactor RegulationEnclosures:As stated Enclosure 1Additional Details on Integrated SafetyAssessment Program II (ISAP II)A probabilistic risk assessment (PRA), operating experience review, andintegrated assessment are the bases of the ISAP II process for determining,ranking, and resolving issues. Licensees may need to perform deterministicevaluations of those plant issues that cannot be evaluated within the contextof a PRA. The minimum acceptable PRA would be a Level 1 PRA.* The utilitywould be expected to periodically update its PRA so that plant configurationand procedural changes are reflected in a timely manner. Periodic updateswithin 2 months of significant changes would be typical. The process of main-taining a PRA with appropriate management attention would favorably demonstratemanagement involvement. For multi-unit sites, the utility would need to havePRAs that consider the different features of each unit.The operating experience review would evaluate total plant operating experienceto determine any particular systematic weaknesses and trends. The experiencereview then would be used as a tool against which to compare the PRA findingsand validate their reasonableness. The staff has not yet determined whetherit or licensees will evaluate the operating experience review to identify trends.However, as part of the PRA, the staff would anticipate that utilities would makeuse of plant-specific equipment failure rates and performance data. The reviewof this type of information would be the first step in an operating experiencereview.The Level 1 PRA, along with completion of a containment vulnerability analysis,(or the Level 2 or 3 PRA) would allow a utility to complete its IPE for thatparticular facility because, as the Severe Accident Policy Statement requires,vulnerabilities would be identified and addressed on a plant-specific basis.For ISAP II participants, these vulnerabilities would be evaluated and rankedfor overall safety significance i.n order to assume their appropriate priorityas compared to other issues. ISAP II participants could address these vulner-abilities in the time frame of the IPE response and would not be penalized forparticipation in ISAP II by the staff requiring participants to address the vul-nerabilities ahead of the IPE schedule. Details of how a containment vulnera-bility analysis should be performed will be provided in the IPE generic letter.Issues required by regulation, order, or license condition and items committedto by the licensee would be included in ISAP II as a minimum. The utility,at its discretion, also may opt to include its own initiatives in ISAP II.The benefit of expanding the ISAP II list of issues is that licensee-initiateditems may have a higher safety significance than some NRC-specified items (andmay allow certain items to be deleted from the licensee's schedule) becauseof their greater contribution to overall plant risk reduction. For instance, a*The PRA levels are defined as follows: Level 1 is the determination of core meltfrequencies based on system and human-factor evaluations; Level 2 is the deter-mination of the physical ana chemical phenomena that affect the performance ofthe containment and other mitigating features and the behavior of the fissionproducts within the plant; and Level 3 is the determination of the offsitetransport, deposition, and health effects of fission product releases.
licensee could initiate a trip reduction modification that, although not an NRCrequirement, could significantly reduce plant risk and hence could rank higher inpriority than some NRC items.ISAP II also would include future issues that would be incorporated into theprocess as they arise. Future issues would include new utility and staffissues and newly resolved generic issues. The staff would not require ISAP IIparticipants to address generic issues ahead of the rest of the industry. In-stead, as resolution is achieved, these generic issues will be evaluated forthe specific facility within the overall context of ISAP II.A tentative schedule for initiation of ISAP II with a given utility is provided inTable 1. This schedule is subject to change as the program evolves. Once thescope of issues to be included in ISAP II has been determined by the NRC and thelicensee, the licensee would evaluate the issues on an integrated basis, proposeresolution of the issue, and place each issue into one of three categories basedon such criteria as safety significance and contribution to risk reduction, per-sonnel exposure, and ease of implementation. As a general rule, issues that areranked highest should be resolved in approximately one refueling outage, or twoat most; issues ranked in the middle should be resolved in two to four refuelingoutages; issues ranked lowest may be deferred to four refueling outages and maybe considered for dropping from the utility's schedule. The specific rankingcriteria would be developed by each utility.The licensee then submits its evaluation, solution, and ranking of each issueto the NRC for review. Following resolution of staff comments, the staff willissue an Integrated Safety Assessment Report (ISAR) documenting the agreed-uponresolution of each issue. In the pilot ISAP, this document was a draft ISARthat was circulated for peer review ana ACRS cornents. In ISAP II, the staffwill issue only a final ISAR. The draft ISiARs for Millstone Unit 1 and HaddamNeck are NUREG-iI8A dated April 1987 and NUREG-1185 dated July 1987, respectively.Following issuance of the ISAR, the staff and licensee will negotiate anintegrated schedule detailing milestones and completion dates for each issueor decide whether an issue should be dropped.To instill a certain amount of rigor to the process, the staff would requirethat the operating license be amended to include ISAP II by, at a minimum, out-lining the process for modifying accepted schedules. The staff also may opt toinclude the schedule for significant items in the license condition. The staffwill work closely with the licernsee prior to license amendment submittal to de-velop an acceptable application. The need to revise the integrated schedulewould likely be evaluated following each outage as an integral part of the prep-aration for the subsequent outage. Justification for schedule changes wouldinclude newly identified issues by the staff or licensee, changes in NRC regula-tions, modifications in the scope of scheduled work, and delivery or procurementproblems. The staff envisions a certain category of items for which staff approvalis not required to change schedules as long as the schedules of significant issuesare not negatively impacted. However, if the staff or licensee determines thatprompt action is required on an ISAP ' issue to protect public health and safety,the action must be taken on an accelerated schedule consistent with the item'snewly identified safety significance.
Table 1Tentative ISAP II ScheduleElapsedTime0TotalTime06 weeks 6 weeks4 weeks 10 weeks12 weeks 22 weeks10 weeks 32 weeksNRC selects participants, informs utilities, andrequests submittal of the licensee's PRA* and theproposed scope of ISAP II for each facility.Individual utility scope submittals received.NRC reviews and completes resolution of questions onscope.Utility evaluation, proposed resolution, and ranking ofeach issue submitted to NRC.Resolution of staff comments of utility evaluation andranking submittal complete; schedule negotiationsbegin.Schedule negotiations complete.Utility submits proposed license condition.Sholly notice for license condition is issued.License amendment is issued incorporating ISAP II.12 weeks2 weeks4 weeks4 weeks44 weeks46 weeks50 weeks54 weeks*The submittal time and staff review period for each facility would vary depend-ing on the status of the licensee's PRA and the extent of previous staff review.Therefore, the PRA schedule is not included in the tentative schedule which wouldhave to be modified to include the PRA review on an individual facility basis.
Enclosure 2Integrated Safety Assessment Program (ISAP) IIResponse Format to Generic Letter 88-02Facility Name:Utility:Individual Contact Name:Phone Number:An expression of interest will not be considered a commitment to participateon the part of the utility.1. Would you be interested in participating in ISAP II?frame?If so, in what time2. Do you believe that an industry/NRC seminar consisting of a brief discussionby NRC followed by a question and answer period would be beneficial prior,to making a decision?3. Would you be interested in a one-on-one meeting with the UPC to discussyour particular facility or facilities?4. If you remain undecided regarding participation, what additional informationdo you need in order to make a decision?5. Do you have any potential concerns about participating in ISAP II?6. Do you have any suggestions for program improvements or changes?
LIST OF RECENTLY ISSUED GENERIC LETTERSGenericLetter No.GL 66-01Date ofIssuanceSubiect"NRC POSITION ON IGSCC IN BWRAUSTENITIC STAINLESS STEELPIPING"Issued ToALL LICENSEESOF OPERATINGBOILING WATERREACTORS ANDHOLDERS OFCONSTRUCTIONPERMITS FORBWRSbL 87-16NUREb-1262. "ANSWERS TOQUESTIONS AT PUBLIC MEETINGSRE IMPLEMENlATION OF 10 CFR55ON OPERATORSLICENSES11 / 12/67ALL POWER ANDNONPOWERREACTORLICENSEES ANDAPPLICANTS FORLICENSES5L 87-15 POLICY STATEMENT ON DEFERREDPLANTS11/04/87ALL HOLDERS OFCONSTRUCTIONPERMITS FOR ANUCLEAR POWERPLANTGL 87-14GL 87-13REQUEST FOR OPERATOR LICENSESCHEDULESINTEGRITY OF REQUALIFICATIONEXAMINATIONS AT NON-POWERREACTORS08/04/8707/ 10/87ALL POWERREACTORLICENSEESALL NON-POWERREACTORLICENSEESGL 86-12 50.54(f) LETTER RE. LOSS OFRESIDUAL HEAT REMOVAL (RHR)DURING MID-LOOP OPERATION07/09/87ALL LICENSEESOF OPERATINGPWRS ANDHOLDERS OFCONSTRUCTIONPERMITS FORPWRS.L. 87-ilGL 87- 1RELAXATION IN ARBITRARYINTERMEDIATE PIPE RUPTUREREQUIREMENTSIMPLEMENTATION OF 10 CFRi'.57. REQUIREMENTS FOR FBICRIMINAL HISTORY CHECKS/ 3 ' e .E8 706/ 12/e7ALL OPERATINGLICENSEES.CONSTRUCTIONPERMITHOLDERS. ANDAPPLICANTS FORCONSTRUCTIONPERMITSALL POWERREACTORLICENSEESSECTIONS ;.1 ANID 4.0 OF THE31ANDARD TEEHNICALSPECIFICATiONS ON THE"PPLICABILIT'Y OF LCO ANDSURVEILLANCE RECUIREMENTS)6/ 04 /Ei'.AsLL LIGHTWATER REACTORLICENSEES ANDAPPLICANTS