ML20056E371

Requests Commission Approval of Revised Guidelines for Prioritization of Generic Safety Issues

ML20056E371
Person / Time
Issue date:	04/28/1993
From:	Taylor J NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:
References
SECY-93-108, NUDOCS 9308230261
Download: ML20056E371 (62)

Text

WMMMMMWNSSSS go

.. m...

,o m..........

7._:t 5xq 7 m:T rm p m rL

_s 3[A\\^

\\,,,,, /

{

j

._ cccm..-..cd /....:

POLICY ISSUE April 28,1993 SECY-93-108 (NEGATIVE CONSENT)

FOR:

The Commissioners FROM:

James M. Taylor Executive Director for Operations

SUBJECT:

REVISED GUIDELINES FOR PRIORITIZATION OF GENERIC SAFETY ISSUES PURPOSE:

To seek Commission approval of revised guidelines for prioritization of generic safety issues (GSIs).

BACKGROUND:

SECY-92-135, " Progress of Resolution of Generic Safety Issues," dated April 15, 1992, provided an overview of the Generic Issue Program.

A periodic briefing on the subject was presented to the Commission on April 24, 1992.

This paper is a part of the response to the Staff Requirements Memorandum, dated May 13, 1992, resulting from that briefing. The SRM suggested that the staff examine completed GSIs to determine opportunities for saving efforts without a significant difference in the outcome.

DISCUSSION:

In light of ten years of experience with the 1983 prioritization scheme, the staff proposes to make adjustments in the numerical prioritization formula by raising risk thresholds and simplifying the way in which costs enter the priority rankings.

SECY NOTE:

TO BE MADE PUBLICLY AVAILABLE WHEN THE FINAL SRM IS CONTACT:

Ronald Emrit, RES MADE AVAILABLE.

(301) 492-3731 I

9308230261 930428

?

PDR SECY

.UU 93-108 PDR

\\

k VMMMMMMMMMMMMMMMMA

r

. The motivation for raising the risk thresholds is the observation that only three of the 27 MEDIUM-priority issues resolved -- and only about half of the HIGH-priority resolved issues -- resulted in a decision to take regulatory

action, i.e., in retrospect, resources appear to have been devoted to j

resolving a large number of issues with no safety improvement resulting.

This outcome must be interpreted with the qualification that generic issue resolution efforts that have not led to regulatory action have, nevertheless, in many instances, produced safety benefits through voluntarily licensee actions -- in consideration of the issues raised -- or in response to interim guidance. However, the extent of these benefits, when they occurred, was generally in proportion to the priority rank, and MEDIUM-priority issues usually resulted in marginal improvements. The threshold adjustments are intended to cause the prioritization process to model the resolution process r

without the earlier, apparently excessive margin for initial uncertainties, to reduce resolution efforts that do not produce safety improvements, while still i

ensuring attention to issues that require it. The raising of the numerical safety thresholds will be accompanied by strengthened attention to uncertainties and special considerations, to help recognize instances when a priority rank higher than the indication from the new numerical formula is warranted, the objective being to improve the efficiency of the prioritizations without impairing their prudence. This should allow available i

resources to be focused on issues of higher priority and result in improved schedules for resolution.

The simplification of the way in which costs are used in the prioritization process reflects the confirmation from experience that risk significance is indeed the primary factor in priority ranking, with a more bounded role for i

safety-cost tradeoffs.

The GSI prioritization guidelines are delineated in the Introduction of NUREG-0933, "A Prioritization of Generic Safety Issues," which is periodically updated.

Enclosure I presents the proposed revised guidelines for inclusion in NUREG-0933. The revised sections of the proposed guidelines are shown in shaded text; text that has been deleted is shown lined-out.

L The proposed revised prioritization scheme has been applied to the 64 GSIs originally identified as HIG W or MEDIU Wpriority. The results of this evaluation are presented in Enclosures 2A and 2B; the titles of the 64 GSIs considered in this evaluation are given in Enclosure 2C.

The results summarized in Enclosure 2A show that 13 of the 17 HIGW and MEDIUWpriority GSIs that were resolved with reouirements would be ranked HIGW or MEDIUWpriority with the proposed criteria.

Three MEDIUM-priority issues that were resolved with requirements would be in the DROP category.

One HIG W priority GSI was ranked without quantitative estimates. An explanation of the disposition of these 3 GSIs is included in Enclosure 2A.

The results summarized in Enclosure 2B show that 21 of the 47 HIGN or MEDIUW priority GSIs that were resolved with no reouirements would be ranked HIG W or MEDIUWpriority with the proposed criteria.

Eighteen of the GSIs that were resolved with no requirements would be ranked LOW or DROP.

Eight of the 47 GSIs were ranked without quantitative estimates.

t aw--

I Overall, using the proposed revision to the prioritization guidelines would have resulted in pursuit of the resolution of 43 of the 64 GSIs originally identified as HIGH-or MEDIUH-priority.

1 COORDINATION:

The ACRS has reviewed the proposed revised guidelines and their comments are i

contained in Enclosure 3.

The staff response to these comments is contained in Enclosure 4.

RECOMMENDATION:

That the Commission:

Note that the staff intends to implement the proposed revised prioritization guidelines unless otherwise directed by the Commission.

i

-W s6k f ames M.

ylor Executive Director j

for Operations

Enclosures:

1.

Proposed Revised Introduction to NUREG-0933 2.

A. Comparative Priority Ranking of HIGH and MEDIUM Priority GSIs Resolved With New Requirements (11/83 to 9/92)

B. Comparative Priority Ranking of HIGH and MEDIUM Priority GSIs Resolved With No New Requirements (11/83 to 9/92)

C. Comprehensive Listing of 64 GSIs Resolved Up to 9/30/92 3.

ACRS Letter Dated November 12, 1992 4.

Staff Response to 11/12/92 ACRS Comments f

SECY NOTE:

IN THE ABSENCE OF INSTRUCTIONS TO THE CONTRARY, SECY WILL NOTIFY THE STAFF ON THURSDAY, MAY 13, 1993, THAT THE COMMISSION, BY NEGATIVE CONSENT, ASSENTS TO THE ACTION PROPOSED IN THIS PAPER.

DISTRIBUTION:

Commissioners OGC OCAA IG OPP EDO ACRS SECY

4 S

ENCLOSURE 1 l

PROPOSED REVISED INTRODUCTION TO NUREG-0933 l

5 Revision 4 f

INTRODUCTION I.

BACKGROUND

\\

l Historv On October 8, 1975, the Commission directed the staff to develop "a i

program plan for resolution of generic issues and completion of technical projects." The Commission further requested that "this plan should include: task schedules... task priority and manpower requirements (with 2

proportions of staff contract efforts explicitly identified)." On December 12, 1977, the Energy Reorganization Act of 1974 was amended by Congress through Public Law 95-209 to include, among other things, a new Section 210 as follows:

UNRESOLVED SAFETY ISSUES PLAN Sec. 210. The Commission shall develop a plan providing for specification and analysis of unresolved safety issues relating to nuclear reactors and shall take such action as may be necessary to implement corrective measures with respect to such issues. Such plan shall be submitted to the Congress on or before January 1,1978 and progress reports shall be included in the annual report of the Commission thereafter.

In order to meet both Commission and Congressional directives, the staff developed a generic issues program that provided for the identification of generic issues, the assignment of priorities, the development of detailed action plans, projections of dollar and manpower costs, continuous high level management oversight of progress, and public i

dissemination of information related to the issues as they progressed.

1 This program was published in NUREG-0410"' in Januar{"1978 and, shortly thereafter, the Commission issued a Policy Statement on the NRC

" Program for Resolution of Generic Issues Related to Nuclear Power Pl ants. "

The NRC generic issues program published in NUREG-0410"' was considerably broader than the " Unresolved Safety Issues Plan" required by Section 210.

It included plans for the resolution of generic environmental issues, for the development of improvements in the reactor licensing process, and for j

consideration of less conservative design criteria or operating limitations in areas where existing requirements might be unnecessarily restrictive or costly.

Oy2f/93 1

NUREG-0933 I

Revision 4 i

The first attempts by"the staff to implemeni. the generic issues program stated in NUREG-0410 were based largely on engineering judgments. This qualitative effort to rank unresolved generic issues continued through two phases:

(1)

In 1977, all issues were classified into four categories according to importance, from "significant" to "little or no importance."

(2)

In the early part of 1978, the issues were reclassified into Groups 1 through 8 by type rather than by order of importance.

Later in 1978, the staff began to take a quantitative approach by using risk assessment to place the issues into four categories ranging from I (potential high risk items) to IV (items not directly related to risk).

With increased confidence in this risk assessment approach, the staff introduced a more comprehensive quantitative system in early 1979.

Points were assigned to each issue based on an assessment of safety significance, environmental significance, licensing effectiveness, deadline pressure, and retrofit versus forward-fit. Although the point system was still quite subjective, it was nevertheless a major improvement over the previous methods used.

In the aftermath of the Three Mile Island Unit 2 (THI-2) accident, many new generic issues were raised and the staff came to the conclusion that the point system was too subjective to be used for ranking the issues.

One of the THI Action Plan'* items, IV.E.2, called for the staff to develop a plan for the early resolution of safety issues.

It was in resolving this issue that the staff developed a quantitative "prioritization" methodology whereby a numerical priority score could be assigned to each generic safety issue. With this approach, priorities were to be based on an evaluation of the estimated risk reduction as:ociated with the potential change in requirements that could result from resolution of an issue and the estimated costs to the NRC and the industry in implementing such a change.

This methodology was submitted to the Comission for information in SECY-81-513.* In April 1983, this approach was refined and resubmitted to the Comission for approval in S ECY-83-221. 22**

After Comission review, approval to use the methodology was given in November 1983.**"

T h36 sis'simiinf71992WiWillihU6f?h'ihs?iFIFs'7sFpsFIIHEs"M thTt.fisW983 p ri ori ti zat i onischeme n adj ds tment s +ere;made M n? the ?hume ri cal s tbres hold 5 whileietaining thsrba'sickfeatsesMfithelmeth'odidTheiadjustnnt's~~~~~1 i nvolfed irai s i ng ! ri sk)t hreshol dsland Simpl;t fyingi the} VajM ni whichsiiiG ente redithe ? prioFity rrankingsb What; motivated ithe r ra i si ng t o ff risk ~~~

thre shol ds? wa s sthe { observitio@thatiLohly! threelo fs thef 27j MED IUMsrf6Hff issuestresolved H-JandTonlyJaboutihalf"of;the?HIGH-prioritydresolved~~~ ~

i s s u es;-gesul ted dn[ajeci s_lonjg t akelregul atoryiacti on;lileMj n Oy22/93 2

NUREG-0933

Revision 4 FifF6spiEEDt?ippiiFid;thit@TsourcesJsys[SisE"ds;V5fedEE6TFis519]69?i largeinumberbf; issues withenossafety? improvement)resultinghGhis Fesolutionf effoEts(that?havernottled;to f regulatoryfactionihne" Missus outcomelmustibsVinterpreted!withithe qualificationsthatigsneric heverthel ess MinimanyJisstancesWproduced ;s afeti) bene fitsh thr6sih l i censee ?abti 6nsita ksn iv61 sntari lyM 31 nson' 'i dera ti oni oft iheli s sdsi s

rai'ed W o W n sesponssltofinterimiguidancefn Howese Q ths?extentsof s

the s sitHkne fi ts dwheni thei70dchffsd d wsigenerEl lfH s prop 6 Eti6hlt61thI pdi6rit$pnQjQEDItEjpi,orityjfssuesgesulted[ijr[ussa))P]mahihal^

3 improvements;g thTlfifi~shilTidjUilisiisEsiweredifli~ndidito[cassEIiHi?pTGEllTz'iYi3H 6 del utheirsssisti oW5roces s%ithoutithijsarlisMappsFsEfly prsesss%eargini fo@fsafetisimpfensentsMhn eistill eic#isiveY nitnlysheertaint'iesEtd?Fedscsifesblution?efforti that:idoin6t@ rods 6e totissues?thatWsquipetit " TtMfsis%glsfAthel%siesital4 safety ~fissTi63

~~~"

'hfisholditisEsscompanisdl istfe'nithsned%ttentiosit6FehditiiH t

iipscialsti>ssideFationiStot pifecognizelinstan6ei9 shen % phi'6B tys fan k higherdhanithisisdicatisnifromithfineWnGssricalsformalifisMifEantedf l

theYbbjectips;tsinsitogspfoiesthejffic] encMfithejrlojitJzatjbni;~ sit.houtijspaitigitheinprudgges TEs'YIapTiffciff55T4fsthe7wayziHWcli?cosisissreEFifTellT!Ih~s EbnfiFmation!fromiexp@rien' eitntM sEsigni ff ein6siisi;indesditWeTpEr c fastopinMrjhitigan g M(ithjf morelbopndedj lof$$4fetyjcosf^~ trade-offy ifie~ERTFWy7FiBEthiTeraFffiidTFfsEEftifiiroidiNsedWWFpaTrTffilfrEni comp,l et_edjbe fb?EOs t 5 EF~Ti~ 1002'sojfag[agjhownlidgpsjd,1gCf ~ ~ Operatina Plan The initial work in prioritizing issues was essentially done by various Staff Working Groups. Following a reorganization of the Office of Nuclear Reactor Regulation (NRR) in April 1980, the lead responsibility for prioritization was assigned to the Safety Program Evaluation Branch, Division of Safety Technology, Office of Nuclear Reactor Regulation (SPEB/ DST /NRR). The 1983 NRC Policy and Planning Guidance (NUREG-0885, Issue 2),"* in addressing the area of Coordinating Regulatory Requirements (Planning Guidance, Item.E, p.6) called for "...a priority list of generic safety issues including THI-related issues based on the potential safety significance and cost of implementation of each issue..." to be submitted to the Comission for approval. Using the prioritization methodology outlined below, this list was developed by SPEB in response to the Planning Guidance and forwarded to the Comission in SECY-83-221." After another NRR reorganization in November 1985, this task was assigned to the Safety Program Evaluation Branch, Division of Safety Review and M/2f/9) 3 NUREG-0933

l Revision 4 Oversight (SPEB/DSR0/NRR). Following an NRC reorganization in April 1987, the responsibility for preparing and maintaining the list of generic safety issues and their priority was assigned to the Advanced Reactors and Generic Issues Branch, Division of Regulatory Applications, Office of Nuclear Regulatory Research (ARGIB/DRA/RES). The prioritization of generic issues is an ongoing staff function that has been reflected annually in the NRC Policy and Planning Guidance.**" This document was superseded in 1987 by the NRC Five-Year Plan. II. GENERIC ISSUES PROGRAM After issuance of the Policy Statement"" in 1978, the NRC program to resolve generic issues underwent many reviews and changes. As a result, the Comission concluded in April 1989 that the 1978 Policy Statement no longer reflected the NRC's generic issues program and withdrew it from the public record."" The current generic issues program consists of six separate and distinct steps: identification, prioritization, resolution, imposition, implementation, and verification (See Exhibit A). An explanation of each of these six steps is given below. Identification Generic concerns may be identified by individuals or organizations within the NRC staff or by the Advisory Comittee on Reactor Safeguards (ACRS), the nuclear power industry, or the public. RES Office Letter No. 1 (0L

1. 1)"" provides a procedure and suggested content for individuals or organizational units within the NRC to request consideration of a concern as a new generic issue. This procedure may also be used by parties outside the NRC to express their concerns to the staff for consideration as potential generic issues. Sources of potential generic issues are many and varied and include, but are not limited to, the following:

evaluation of safety-related research, risk assessment analyses, and public and industry concerns. Prioritization This report focuses on the prioritization step of the generic issues program which is explained in detail in Paragraph III below. Resolution After an issue has been prioritized and approved for resolution, the first task is the development of a plan to delineate the work to be done, assignment of major responsibilities, identification of project resource needs, and scheduling of milestone detes. These activities vary in scope and depth in accordance with issue priority and the depth of information on a given issue. The second task involves development of a technical solution. Typically, the information used to resolve an issue comes from experience data, experiments, tests, analyses, and probabilistic risk I [4]2219] 4 NUREG-0933

4 Revision 4 GENERIC ISSUES PROGRAM IDENTIFICATION t V PRIORITIZATION i Y i RESOLUTION i i V J l IMPOSITION e l V \\ IMPLEMENTATION V P VERIFICATION Exhibit A 69I2M] 5 NUREG-0933

Revision 4 assessments (PRAs). The results of such work c;- the technical findings may be published in contractor and staff NUREG reports which are made Exhibit A available through the NRC Public Document Room (PDR), Washington, D.C., or the National Technical Information Service, Department of Commerce, Springfield, Virginia. In the final stage of resolution, the technical findings are used as a basis to develop a proposed resolution for the issue involving a change to NRC requirements or guidance. Several alternatives may be considered. A regulatory analysis, including a detailed cost / benefit analysis of each practical alternative, and consideration of the best methods of imposition, implementation, and verification are used in selecting a proposed resolution. If a backfit is proposed, first, a determination is made as to whether the backfit is required to provide adequate protection to the health and safety of the public or simply provides for enhancement of public health and safety. If it is determined that the backfit is necessary to provide an adequate level of protection, the backfit will be imposed regardless of the costs to achieve it. If it is determined that the backfit provides for enhancement of public health and safety, a generic analysis is required that treats the nine factors specified in 10 CFR 50.109(c).2 Once the cognizant NRC Office Directors have agreed to a proposed resolution, it is then forwarded to the Committee for the Review of Generic Requirements (CRGR), the ACRS, the Executive Director for Operations (EDO), and the Commission for review and approval as appropriate. Changes to regulations, Policies, the Standard Review Plan (SRP), and Regulatory Guides are published in the Federal Register for public coment. Comments received are then incorporated, as appropriate, with the fint1 product published in the Federal Register. Resolution of a generic issue can take from several months to a few years depending on the length of time required by the deliberations involved at each of the above steps. RES Office Letter No. 3"" describes the procedure to be followed in the resolution of a generic issue, denotes the required elements of the resolution plan and resolution package, and identifies review procedures i and organizational responsibilities for the approval of the resolution of a generic issue. Guidance for the preparation, review, and required content of the regulatory analysis portion of the resolution package is provided in RES Office Letter No. 2."" Milestone information and reporting requirements as well as organizational responsibilities for the tracking of generic issue resolution are provided in OL #1."" All issues scheduled for resolution are tracked through the resolution process by the Generic Issue Management Control System (GIMCS) which is updated quarterly and placed in the PDR. Imposition MImposition" is the step in the generic issues program where each Effected liEensee and/or applicant is required or:gsided to prepare a schedule for implementing the generic issue res51utish~Eonsistent with a Oy22293 6 NUREG-0933

Revision 4 Rule, Policy, Regulatory Guide, generic letter, bulletin, and/or licensing guidance developed during the resolution stage. Normally, NRC requirements, policies, and/or guidance will not provide for NRC consideration of a licensee's modifications prior to their implementation ~ at an affected plant. This facilitates completion of plant modifications to enhance safety within two refueling outages, not to exceed three years after issuance of NRC requirements, policies, and/or guidance.

However, in a few exceptional cases, licensees may be required eipeatid to submit (normally for NRC approval) their plans (including scheduT6)"for plant modifications prior to their implementation.

In all cases, licensees will be reg @ed bxpscted to certify in writing to the NRC that plant modifications have been completed. For the exceptional cases, the staff reviews each applicant's and/or licensee's submittal with regard to proposed modifications to site, equipment, structures, procedures, technical specifications, operating instructions, etc. and schedules proposed for the accomplishment of the modifications. For backfits, requirements fimposition" is complete when each affected licensee has Eommitted to com511ance act' ions and schedules for implementing these actions. Fornewforward-fitsirequirccats,the

• imposition" of a, generic,. issue resolution is complete when the new requirementM orfguidance becomes effective as an integral part of NRC regulations, polifdsT ihd/or guidance.

During the imposition Ws stage, a resolved GSI is identified as a Multiplant Action (MPA)~for licensee action. The allMPAsistrackedintheSafetyIssueManagement'fimposition!statusof System (SIMS). Imolementation Implementation is the step in the generic issues program where the affected licensees perform the actions on existing plants to satisfy the commitments made during the imposition stage. These may include modifications / additions to equipment, structures, procedures, technical specifications, operating instructions, etc. No later than 30 days after each affected licensee has completed all of the actions required for a particular generic issue resolution, and the modified / additional system is fully operational, the licensee is required to certify in writing to the NRC that plant modifications have been completed in accordance with NRC requirements, policies, and/or guidance. When all affected licensees have officially notified the NRC of completion of all required / committed actions, the implementation stage is complete, unless it is determined by the staff from subsequent verification inspection that additional licensee actions are needed for compliance. Verification The verification step consists of three parts. First, the portions of a licensee's actions, if any, that warrant NRC inspection must be determined. This decision is made during the resolution stage based on OM2Q93 7 NUREG-0933

i Revision 4 the judgment of the safety significance of the issue relative to other matters in the inspection program, licensee performance, and the resources needed to accomplish a meaningful inspection. Next, as necessary, inspection instructions are prepared to ensure that the NRC inspection is performed in a consistent and appropriate manner at all affected plants; the inspection, by its very nature, is an audit. Therefore, carefully thought-out instructions must be provided to the NRC inspectors so that the maximum safety benefit is achieved for the limited resources devoted to this effort. The third part of the verification process is the actual verification and documentation of the results in an inspection report. Physical inspections are performed on an audit basis in a manner consistent with general inspection procedures which involve a sampling of changes made by licensees or applicants, as opposed to a 100% inspection of all actions. Verification of licensee implementation of generic issue resolution is reported by the staff in SIMS. III. PRIORITIZATION Purpose and Scope The primary purpose of prioritization is to assist in the timely and efficient allocation of resources to those safety issues that have a high potential for reducing risk and in decisions to remove from further consideration issues that have little safety significance and hold little promise of worthwhile safety enhancement. However, issues of such gravity that consideration of immediate action is called for are excluded from prioritization because of the compressed time scale in which decisions for such issues must be made. NudRiii"FiiBTTiET65Eofss5WREsififfifissi'i[S5;ERisidfTGif5fdii~rFsn] r p1 antsiand sappl i cati on ttos fdture! pl antsrare? considered A~thes p~rioirity ~ ~ ~~ rankingMsfdeletminsdionithMograting&lintiitdsist ~ Prioritization focuses on generic safety issues (GSIs) 1.e., safety concerns that may affect the design, construction, or operation of all, several, or a class of nuclear power plants and may have the potential for safety improvements and promulgation of new or revised requirements or guidance. However, the method can be used to identify changes in current requirements that could significantly reduce the impact (usually cost) on licensees without any substantial change in public risk. Issues of this type are classified as Reaulatory Impact issues (RI) to clearly differentiate them as not improving the safety of nuclear power plants but, nevertheless, possibly worthwhile. In order to identify GSIs, all issues originated in accordance with OL

1. I"" are reviewed to determine their safety significance.

Issues that primarily concern environmental protection or the licensing process and do not involve significant safety improvement elements are classified i accordingly and noted for separate consideration outside the GSI priority ranking scheme. These issues are classified as either environmental 0_4222/93 8 NUREG-0933

s t Revision 4 issues or licensing issues. Environmental issues (EI) involve impacts on the human environment and the values sought to be protected by the National Environmental Policy Act (NEPA). Licensina issues (LI) are not 4 directly related to protecting public health and safety or the envi-ronment, but relate to: (1) increasing the staff's knowledge, certainty, t and understanding of safety issues in order to increase its confidence in assessing levels of safety; (2) improving or maintaining the NRC i capability to make independent assessments of safety; (3) establishing, I revising, and carrying out programs to identify and resolve GSIs; (4) documenting, clarifying, or correcting current requirements and guidance; and (5) improving the effectiveness or efficiency of the review of applications. 1 The list of issues sabjected to prioritization contains the following l groups: j (1) TMI Action Plan items identified for development in NUREG-0660" these issues are covered in Section 1. The priority recommendations in this report exclude those issues that were designated for implementation in NUREG-0737." (2) Task Action Plan items identified in NUREG-0371' and NUREG-0471,* plus the subsequently added issues A-42 through A-49 that were designated as Unresolved Safety Issues (USIs); these issues are covered in Section 2. However, issues designated as USIs were 4 excluded from prioritization because of the high-priority attention they were given based on priority decisions previously made. In the future, USIs will come from issues-that have been prioritized. (3) New Generic issues identified by the staff, ACRS, or others; these ) issues are covered in Section 3. All new issues identified will be l prioritized and included in Section 3 and published in future supplements to this report. (4) Human Factors Program Plan (HFPP) items identified for development in NUREG-0985"'; these items are covered in Section 4. I (5) Chernobyl Issues identified in NUREG-1251 '"; these issues are 2 l covered in Section 5. A comprehensive listing of all issues in the above five groups is given in Table II which includes the following information for each issue: (1) -l the NRC person responsible for the prioritization evaluation; (2) the j lead NRC office, division, and branch responsible for reviewing the prioritization analysis and/or resolving the issue; (3) the priority - ranking or status; (4) the latest version of the evaluation; (5) the issuance date of the latest version of the evaluation; and (6) the MPA 4 number for those issues that have been resolved and require licensee - actions. A summary of the number of issues in each category is shown in Table III. A cross-reference listing of reports prepared by the Office $Q2QS3 9 NUREG-0933 v--.e- ,?-e .a p-..,

Revision 4 for Analysis and Evaluation of Operational Data (AE00) and their corresponding generic issues is provided in Table IV. How the Work Is Done The work is done, in accordance with the criteria described below, by the responsible NRC Branch in consultation with others in the NRC with knowledge of the issues or expertise in the Lechnical disciplines involved. In a number of instances, technical or cost information is obtained from industry and other outside sources. The Battelle Pacific l Northwest Laboratories (PNL), under a teckc. al-assistance contract, developed detailed methods to quantify safety benefits and costs and provided safety-benefit analyses and cost information for many of the issues. The responsible NRC Branch, with internal consultations as necessary, reviews and applies the PNL-supplied technical factors, in conjunction with additional factors, in developing the priority rankings and recommendations. Systematic peer review of each prioritization evaluation within the NRC contributes to the assurance that the analysis is complete and accurate and that the judgments are soundly based. This review is done in two stages. First, each analysis is reviewed by the NRC organizational unit or units whose area of responsibility or specialized knowledge is substantially involved. Second, any comments made are then resolved, where practical, and factored into the analysis, as appropriate. Upon completion of peer review, the analysis is then finalized and prepared for approval by the responsible Office Director. Once approved, it is placed in the PDR and published in a future supplement to this report, after which, additional comments from the ACRS, the industry, and the public are considered in any further reassessment of the issue's priority. Priority Cateaories: Their Meanina and Proposed Use Four priority rankings are used: HIGH, MEDIUM, LOW, and DROP. They are intended for use in guiding allocation of NRC resources and scheduling of efforts to resolve the various issues, in conjunction with other pertinent factors such as: (1) the nature, extent, and availability of manpower and material resources estimated to be required; (2) length of time needed to resolve; (3) conflicts in resource allocation and sche-duling among items of comparable priority; (4) status cf affec'ed rear-tors; and (5) budget constraints. A BlGH priority ranking means that strong efforts to achieve the earliest practical resolution are appropriate. This is because: (a) an important safety concern may be involved (though generally the concern is not severe enough to require prompt plant shutdown); (b) cb:tantial ::fety imprcvement i: likely tc bc :ttain:ble at : lcw encugh cc t 10 m ke the imprcycmntwcrthwhile;or(cf{b7theuncertaintyofthesafety assessment is unusually large and an upper-bound risk assessment would 03/2f/9) 10 NUREG-0933

1 Revision 4 i indicate an important safety concern. All unresolved HIGH priority issues are periodically reviewed in accordance with the criteria stated l in NUREG-0705" for possible designation as USIs. A ILS1 is defined as a matter affecting a number of nuclear power plants that poses important questions concerning the adequacy of existing safety requirements for which a final resolution has not yet been developed and that involves conditions not likely to be acceptable over the lifetime of the plants affected." In accordance with Section 210 of the Energy Reorganization l Act of 1974, progress on the resolution of USIs is reported to Congress in each NRC Annual Report. 1 A MEDIUM priority ranking means that no safety concern demanding high-l priority attention is involved, but there is believed to be potential for safety improvements or reductions in uncertainty of analysis that may be substantial and worthwhile. thcugh le:: ;c then for item: :ssigned c HICH pricrity. Efforts at resolution should be planned, perhaps over the ensuing years, but on a basis of not interfering with pursuit of HIGH-priority generic issues or other high-priority work. A LDLW priority ranking means that no safety concerns de'nanding at least MEDIUM-priority attention are involved and there is little or no prospect of safety improvements that are both substantial and worthwhile. When the prioritization process results in a LOW priority ranking for an issue, approval of this ranking by the responsible Office Director signifies that the issue has been eliminated from further pursuit. The DROP category covers proposed issues that are without merit or whose significance is clearly negligible. Issues are also DROPPED from further consideration if it is determined that their safety concerns have been addressed in previously prioritized or resolved issues. When the prioritization process results in a DROP priority ranking for an issue, approval of this ranking by the responsible Office Director signifies that the issue has been eliminated from further pursuit. An issue is considered resolved, indicated by NOTE 3 in Table II, when its resolution has resulted in the establishment of regulatory require-ments or guidance (by Rule, SRP" change, or equivalent) or a documented authoritative decision that no change in requirements is warranted. Priority rankings are not assigned to issues that have been resolved. However, in those cases where issues were resolved after having been identified for further pursuit by the prioritization process, the related i calculations have been retained in the text of this document for future l use. Priority rankings are not assigned to issues that are nearly-resolved (denoted by NOTES I and 2 in Table II) because approval of changes to requirements, based on the resolution of an issue, requires that a detailed value/ impact evaluation of the safety benefit, implementation costs, and other relevant factors be made. Prioritization would duplicate this value/ impact analysis, but in a less comprehensive manner. $/2Y/93 11 NUREG-0933

i Revision 4 i l l Therefore, the effort that would be needed to prioritize an issue is devoted to completing the final evaluation of the issue, rather than i 1 making a tentative judgment as to the importance and value of the issue. Possible resolution of an issue is considered to be identified, indicated by NOTE 1 in Table II, when a possible technical resolution is under 4 evaluation and the evaluation is nearing completion. Further work may be required as part of the review and approval process before a change in i requirements or guidance is issued. Resolution of an issue is considered i available, indicated by NOTE 2 in Table II, when proposed or recommended changes to requirements or guidance are documented in a NUREG report, NRC memorandum, Safety Evaluation Repor! (SER). or equivalent. I Priority rankings are also not assigned to those issues whose safety concerns are determined to be covered (at the time of prioritization) in other issues of broader scope that are being prioritized or are being resolved. Issues in this category are integrated into the issues of j broader scope. A detailed listing of all such issues is given in Table v. l Criteria For Assionino Priorities 1 l 1. Basic Acoroach j The method of assigning priority rank involves two primary elements: (i) the estimated safety importance of the issue; and (ii) the esti-mated cost of developing and implementing a resolution. Special considerations may influence the proper use of the estimates. These elements are applied as follows: (a) The issue is identified and defined. Since issues are often complex and interrelated with other issues, careful definition of an issue's scope and bounds is essential in arriving at a sound and applicable assessment. i (b) A quantitative estimate is made of the safety importance of the issue, measured in terms of the risk (the product of accident probabilities and radiological consequences) attributable to l the issue and the decrease in that risk that may be attainable by resolving the issue. l (c) A quantitative estimate is made of the cost of resolution. I (d) A numerical v luef' ract ;;cre iiipiEENilsiVitis is calculated bydividingthebsk5katidTE65tTentailedibyithe~~eitimated potential risk ridudti66.bTtE3Etiihtid 25H cnt:11cd. Tht ~ l s Orc d nctt; ; V:lu /im' pact rel: tion, i.e., On ::timated r; tic cf : fet improvement value te cost impact. Tiii~faf151ssiiUFEi thi sifek"f}valskrec!hMsdj% fit 6FnlferjthE30s([impag ~^ ~ incurred: 1 04/22/93 12 NUREG-0933 l

i d D I 1 ~ Revision 4 (e) A priority rank (HIGH, P...10M, LOW, or DROP) is obtained by application of criteria in which both the safety significance l; of the issue and. the vphc/ impact based umerical <reeeeimpact/valueiratio are taken into account. The seeeeratio is not' always dirSctly applied to determine the priority ~~ rankings. In some cases, the safety significance of the issue is so great that it demands a HIGH priority, or so winor that is w ited only a LOW priority (or a decision to DROP)i a n e a ment. irrespective of the vehc/impcct;isp^aEQpallu (f) The priority ranking is reviewed and modified, if apprupriate, in light of any special factors (discussed below) that: (i) might bring into question the applicability of the necessarily simplified calculation technique; and (ii) call for special consideration of NRC management decisions or large uncertainties in the quantitative estimates. 1 In summary, while the method has a quantitative emphask, the calcu-i lated numerical values are used as an aid to judgment M r.ot as j determinative of the ranking results. The nature of the specific issue, the quality c' the data base, and the scope of the l necessarily limited vsis determine in each case the dependability of the . erical indications as a judgment aid. 2. Safety Sjgnificance The s:'ety significance of an issue is represented by the reduction in rit m t resolution could effect. Risk is ordinarily expressed here it. erms of the product of the frequency of an accident i occurrence and the public dose (in maehefjbn-rem) that would result in the event of the accident. If more than one accident.:enario is l l important within the necessarily rough risk estimates, the risks are summed. The potential risk reduction calculated in this way is used in j calculating the "vchc/impcct_sj; crc *lsiIa@QW15Qalls as part of the simplified vehe/impcctimpactFTilue analfils, discussed in Paragraph III.3 below. It 'is also used directly as a measure of i safety significance, as discussed in Paragraph III.4 below, in j arrivir.J at a priority rank that is influenced by the safety significance of an issue as well as by the estimated value/~6aitsFif impact relation of a projected soletionM' ~6MWdsisisf6sC66fthe l ~ ~ ~ ^ ~ ~ ~ ^ ~ ~ ~ ^ ~ " ~ " ~ ~ ^ ^ sifetyis@ificancdisl66sj The maapiFs6ii-rem-based risk reduction estimate may not be the only appropriati measure of an issue's safety significance in all cases. For evsmple, when a possible core-meh disgs is involved but i relt outside containment would be miiiBF^of highly improbable, i contrn uion to the core-meM disjE probability may well be more l j indicat.ve of safety significance. Provision is made, as described 0922/93 13 NUREG-0933 i i e

t Revision 4 in Paragraph III.4 below, for use of alternative measures of safety significance in determining a priority ranking when such alternative measures are useful. 3. Wlue/ Ira ct 16sEDV~ lde Relation a The Value/I acct Sccre liii;iiEQyslEE[RifiWFormula a. To the extent reasonably possible, quantitative estimates are made of the possible solu';ons to a GSI by calculating a "pricrity :ccre IspiEQVa'lhelRitjj" that reflects the relation between the risk reduEtion value expected to be achieved and the associated cost impact. The formula for the vclue/ imp;ct SC^rc (S) {p R Qji]Ne j {t Q $ D1s-S - S:f^t, Benefit Sc t pmpgemy [a,fetgeneDj where the safety benefit is the estimated risk reduction (event frequency x public dose averted) that may be achieved, and the cost is that thought necessary to develop and implement a resolution in the number of plants involved. The scoring computation for any issue is then: 3 _ pr7n G gpMC'F where N - number of reactors involved T = average remaining life of the affected plants (years) F = the accident frequency reduction (events / reactor-year) D - public dose from the radioactive material released C - total cost of developing and'iniplE5Fa) ting the from containment (m:n rc )l(person!Fiiii resolution of the issue for all plants affected (=illicas of dollars). The total cost (C) includes both the cost of developing the generic solution, which are typically NRC costs, and the cost of implementing the possible solution at all affected plants, which include design, equipment, installation, test, operation, and maintenance, and are typically industry costs. The QQ22293_ 14 NUREG-0933

Revision 4 priority :ccre (" FatioT(Rphas the units of n rc per millica dollars.bbllar[perjefshhym2 silijWiffididiEulifi6hi"EisillyliiffiEs?iisis" bel)TER approximate si mpact/ val ue i rati oif fi requi red M Rsfef enesishiUl'd be cuadeltM theicurrent2 vsrsion7of et_he tValusilmpacttHandbdok'F ' herejnecessary34supplementithe[genegguidelinesiprojidsd w 5010 % b. Rationale for the Formula The qualitative diversity of factors entering value/ impact analyses in support of GSI prioritization, together with inevitable quantitative uncertainties, make any of various possible value/ impact score formulas necessarily imperfect. Accordingly, provisions are made to compensate for those imper-fections to the extent practical (as discussed in Paragraph III.5 below). The formula selected measures a lifilfio~s~Q" total-safety-benefit tct:1 cost relation. As discussidliEfhis, it is applied within limits set by other possible considerations where a safety issue is either too important to depend on safety-cost tradeoffs or too trivial to merit attention at all. Two principal arguments favor a formula of this type: (1) The w= rat r jfs~nTrilhif5iiis designed as a direct measure of the safety values thif it is NRC's primary mission to protect. The deeMnat+e-numenf6r~3 is designed to measure the overall cost iiiipiEC"^ihiluding industry as well as NRC costs, and should thus reflect the entire public interest in economy. The resulting r: tic (the value/ imp;ct scorc) liii;iaif/Wilie]N)l6}should, subject to the stated caveats, reasonably approximate measuring the overall public interest in safety value received for total resources expended. (2) The allocation of national resources, which in most cases are primarily industry resources, is optimized. c. Risk Estimates The risk estimates developed for GSIs are useful as rough approximations for comparative purposes, but are not necessarily applicable to the assessment of absolute levels of articular issues. Similarly, the risk attributable to p'i6i seeres-provide, for the limited value/ impact /'i~allis7it piirpose of pr16FitTiitioh, tentative assessments of relative potential for cost-effective resolution. They are not intended tobeappliedasvalue/impactdiluedeterminationsforany 0Q22/{3 15 NUREG-0933

\\ 4 Revision 4 regulatory proposal that may ultimately result from efforts to resolve an issue. In addition, the assumed resolutions are not intended to prejudge the final resolutions, but are only assumptions that are necessary to perform quantitative analyses. The basis of frequency estimates generally involves the following: (1) nientification of the specific events which are the basis for the concern, for which the consequences are to be established, and which are to be eliminated or ameliorated by a proposed tecnnical solution (2) Use of event sequence diagrams, fault trees, or decision trees, if possible (3) Identified references and calculations, or stated assump-tions for the numbers used (4) Consideration of the probability of comon mode as well as random independent failures. Exhibit B Release Release Estimated Public Dose" Category (Curies) (Person-rem) PWR-1 1.2 x 10' 5,400,000 PWR-2 9.3 x 10' 4,800,000 PWR-3 5.2 x 10' 5,400,000 PWR-4 2.8 x 10' 2,700,000 PWR-5 1.3 x 10' 1,000,000 PWR-6 1.0 x 10' 150,000 PWR-7 2.1 x 10' 2,300 PWR-8* 7.7 x 10' 75,000 PWR-9* 1.1 x 10' 120 BWR-1 1.1 x 10' 5,400,000 BWR-2 1.1 x 10' 7,100,000 BWR-3 5.0 x 10' 5,100,000 BWR-4 2.1 x 10' 610,000 BWR-5* 1.7 x 10' 20 . Non-core-melt (Other release categories involve core-melt). MThTW10Ef6EC5HiDETeasedIEnd Estimated!Publ i ctD6 set (PersonWsm)Nf1Hbs ~ hpdateditos be Mossi stsntssithi the Mg~si ng" IsllhdD91MPpstvlatpd;g[yere$jagcjdeli[p svaluation3ttilrevise}the soin eMerm i I l OT/2f/93 16 NUREG-0933 6

Revision 4 Where possible, numerical estimates are made based on operating experience, usually Licensee Event Reports (LERs). Other 4 sources include prior PRAs and other risk and reliability studies. Some numbers are based on engineering judgment; in such cases, the basis for that judgment is stated. For the identified end event (s),_the expected radiological con-sequences are expressed in manperson-rem generally based on the radioactive release categories disdibed in WASH 1400** (Appendix VI, pp. 2-1 to 2-5), reproduced as Appendix A to this report. Exhibit B gives estimated C4uries released and approximate population doses for each release category. The computer program CRAC2, applied to a typical midwest site (Braidwood) meteorology, was used for the dose calculations. However, the calculated doses were adjusted to reflect the mean of the population density within a 50-mile radius of U.S. nuclear power plants." Assumptions and a t used for Approach *jations stMKiQtasel(Sti[(b}}p rame ers th_e calcul diijti M [uhde Q BI Qj were as follows: Consequences are represented by the whole body population dose (manpegon-rem) received within 50 miles of the site. An exclusion area of 1/2 mile was assumed with a uniform population density of 340 persons per square mile beyond ) 1/2 mile. This is the mean 50-mile radius population density projected for the year 2000 (NUREG-0348, p.T52)." Evacuation of people was not considered because of the possible large variations in evacuation capability for each plant site. l All exposure pathways were included in the basis of the tabulated numbers except ingestion pathways, i.e., inter-diction of contaminated foods was assumed. (Farmland usage parameters for the State of Illinois were used for separate ingestion pathway calculations where made.) Meteorological data was taken from the U.S. National Weather Service station at Moline, Illinois. ThemanpiFich-remfactorsforeachreleasecategoryaregiven in Exhibit"B'.' Although generally used, consequence estimates were not solely based on these factors. Other factors were used in some cases when more appropriate. An estimated occupational dose of 20,000 manpii~56W-rem from ~~ postaccident cleanup, repair, and refurbishment is also considered. 0Q22/9.3 17 NUREG-0933

Revision 4 Where significant occupational radiological exposure (ORE) is incurred or averted in implementing current requirements or the proposed resolution of a GSI, such exposure is taken into account but stated separately. Where more direct issue-specific ORE information is lacking, dose estimates are obtained by assuming an average dose rate of 2.5 millirem / hour (based on the PNL analysis" cited above) and multiplying by the estimated number of man-hours involved. A second factor is that the risk associated with an issue is more likely to be overestimated than underestimated. Where risk estimates are widely uncertain, a reasonably conservative value of risk reduction is generally selected to help assure adequate priority to issues that may warrant attention. The sum of the estimated risks of all the separate issues will likely exceed the present estimate of the total risk of nuclear power plants because of two facto'rs. First, individual accident sequences can be affected by more than one issue. The resolution of one issue would reduce the probability or consequences of a certain set of accident sequences. Some or even all of these sequences could be the same as some or even all of the sequences affected by another issue. However issues are assessed independently and this interaction ik'IGIE ~~~~ FisEs'ig6ifiEi6Esjis not ifdinirilf~fconsidered. This istWaitidfi"is~itrongest 'f6F~15'5iies related to human factors, since human error affects almost all sequences. The sum of the reductions in core-melt frequency estimated for all of the human factors-related issues may be as much as twice as great as the total human factors contribution to total risk. However, most of the issues not related to human factors are much less strongly interrelated. d. Cost Estimates Because cost estimates are used here only in relation to risk estimates which are generally subject to more or less wide uncertainties, only approximate costs are needed. No separate estimates are generally made for offsite property damage; reasonably conservative use of the public dose estimates is an adequate surrogate in this application. Furthermore, there s no readily-available data on offsite damage that is realistic and detailed enough to make estimates meaningful, reasonably accurate, and generically applicable. If unusual or special offsite effects are not adequately represented by the public dose in some issues, this fact will be considered separately and explicitly in evaluating such issues. 0Q2f[93 18 NUREG-0933

l Revision 4 The expected technical solution on which the cost estimate is based is identified. Estimated costs are established by i collecting available data regarding engineering, procurement, installation, testing, and periodic inspection and maintenance. 1 Where data are non-existent, estimates are based on judgments by the experts involved. Assumptions and estimated uncertainties are identified. Costs are estimated in 1982 dollars. NRC costs include the following: (1) issue identification, analysis, resolution, and report issuance; (2) research to establish proposed specific changes to licensing requirements (or to determine that no change is required); (3) technical assistance contracts (including associated NRC effort); (4) discussions and correspondence with industry owners' groups; (5) plant reviews; and (6) preparation and review of SERs and requirement documents. The estimated cost of NRC professional time is based on $100,000 per person-year. The costs to industry generally consist of some combination of the following: (1) licensing; (2) design; (3) equipment procurement; (4) installation; (5) testing, inspection, monitoring, and periodic maintenance; and (6) plant downtime to effect a change, taken as the cost of replacement power at $300,000/ day. Industrymanpowercostsare6M5I[ij)takenas $100,000 per person-year. In 00mc cc;c, Averted plant damage costs may affect the priority of a GSI. Estimates for such averted costs are devc1 oped and c:cd in : par;tcly :t ted calcul: tion: : that the pricrity :: crc:, both with and without djustment for averted plant d:m:ge cc:t:, Orc rc:dil 531tipTlidi6filhi aEEident?fruijde6EffEd?disdlTdg pp;re n t.negatiYifEistsWUeSiubthbG fromlthsV(positiveFeoitP6ffiiij lementingtihedsb1'utionibfIths~ p issue?" Thi^aurtid'E6Its niiy~1h~cliids tF6ssif~nsFfiid"~~ eqEipinent failures, limited-time plant outage, or limited plant-contamination cleanup. In the extreme, they can also include averted permanent loss of c:e of the plant, estimated at approximately $12 billion present worthd and plant wide cicanup,ctim:tedicn: b::i; con;i: tent dith TMI c: tim:te',") at present worth Of about $'00 million both b :cd en : 5% real di:ccunt rate and EThlffsitlistiTf6NQii6FFIERETEt in615desiths~EastsibF 66thipl antywide%1sAnupdndipennahent loss %ffneisf;the plintydiscountednofpresentiorthibTshdT6s l sv7p realid isc!ountfratesidThisifigure d sWul ffpilid~iH~^EiEh Else by"thi~fEddEtI66'lh~freq5ihEy of~iiich~ivents that would be brought about by resolution of the GSI. The plant loss estimate includes allowance for typical plant age at the time i of the accident as well as replacement power costs together with apportioned cost of a replacement plant. The plant-wide 04/22/93; 19 NUREG-0933 I

Revision 4 vakefimpact/ val lUETFitto pricrity ccre is presented in Figure 1. The thresholdidn the chart are discussed in Paragraphs III.4(b) and III.4 ATriVisi6nft61thif$f;000/peFi6h FemTfiguFefii3hFre(c)below.ntl y1 bei nfc6nsidered j d part Ho f?the 5 programito reviseithe.NRC?siguldelines?for thelperformanchfof" regulatoryyanalysesMThistfigureiwill!befupdatedRas ~ ~~ necessarykwhenjpejrevi.lsedigujdelinesjarejapprovedf ~ IMPACT /VALUET " " 7 "^ " * " ", P " "" SlEGENDi ""^ N"" S/ PERSON-REM w ^ FPRIORITY i ^^ 3 3000j (Ds ~ bl Di k - "- TEl.0Wb . idi. [

. DW D. ROP"~

' ^ ^

• 41l000lt.

g .~ 1-N = f

-=.s..s

., v o.;,

I _ = - + -. $ M'

• i i H' > -;..,..?

/..e C1;000'1

. D. N,. Y M.~j

• lMe v

g ^ s rv .m.mmm%u.' J doi'A-. M0'53.-.. :.2.1._0%.. ~ t,,i, ...-....310 m .m -m u m.m ,{]Zi[RydEitTo')]i[ME[nlCyf6Me4 Diiiiji]FEysihiy2RnY Eii5FEEPFlpF[tDihM65 (b) Preliminary Screenino for Safety Sionificance The value/ imp;ct b;;cd pricrity Occre i Opplied after ; preliminary :creening en the b;;i: cf : fety significance, i.e., the incremental ri k :::cciated with the i::uc. The a:c rdcd a TfiefasssfalHatT3nio65{y bc uch th:t it should bepFioFitij'IF

fety signific nce of en is

ue m:

tFi ss~siliisid s chi safetyls ignifi cance$neNthDiscrsmentab rlik as soci ated :wi thithe /i ssue ;UMHI Gf pFf 6Fi ty~3 sias si gned 9 eni thi~ iinp6rtance i al oiie~Wreg a rdi e s s"6 f" ot he F"^~~~ basisj of safetf"such~ii~in'~iiiitially estimated high cost, which ionsiden.fi6ns, might result in a low priority score. When a GSI is considered important from the safety viewpoint, the assignment of a HIGH priority to its resolution should not be deterred by the initial absence of an identified solution that could be implemented with a moderate cost. At the c.ther extreme, an issue's safety significance could be too minor to warrant diversion of attention from more important safety issues even if it has a 15illispiEfNs1EET^Fitib M9h pricrity :: crc because an inexpihifve sbluti6n~I5bilieved to be available. Below a minimal safety significance threshold, the priority would always be DROP; where the potential risk 04/22/93 21 NUREG-0933 i

v Revision 4 1 reduction is trivial, there can be no basis for regulatory action on safety grounds. In between, there ;y be i',;ue: cf les: extreme import:nce or ,+ 1,. %,+, /mm.+ imo,+ s i n a m m m 4 m,. a 4L4 Aa.m,mA u rn f i tu. f AUi un7 s a wu. vi gvi us s w u s a. u w a s i snyv e susiww wiiu s w w uu s sw u6 i w u s e, u fam .4 m.a, 4 . f Atti U rn f.ttu m m i a 4 4 i. am ...4 =+ ma,4 u vsw u w v er y ya sui 3 6j wi vi v i i usi s us ow s w u i m s.- was gwa um a4+o. avi a wj i ye A ,Lmm TLa m1,b L.,mA mmiam!+o --mL4-n + L - -, L a l w.,, 4.1. =ma v ary 6:si waisv u> w., o w n s i i iiw , isn v u., w w ye avi i 6j i urr T L m m, L,._1 A, ,I onA =I T k1 a maria,+ 4La 4 m., T s k1 a f. u g.o \\ u g,A \\ J. i s .f suwiw i r s e w s riv r u s .j unaw j muuss . ws awws waiw , swn 4,,..a o t ra,4 4 m,. 1, m,. a ...mbam af mm ,+am,

moi,

..,mmsm+ +L.* .m suu. usi issuw un 1 ww w s e ry u aus yw s i wu nw w i vi a 6. u w 6 v 4 s su uj vv u s iuns L. e a k. mmimm4+u 2...a eks+ i n o m 1..., c a m,u., L + n a.+am. s yis u yi sus i.j u., wa r issuw wis u s siiwi rws a vsirw n n iu w ya wwww us i "Cr rcce cI IiCk bU CffCCtb cn y c eM IccC CIO. y TL,w,LalA, /-i U

1. i m /T-no,4 C,. a m. a m

nv w is .r i m i u s gwy vuuvwi a vuws , a m., 4, 4 a a +

n. 4 + L.

4La ,,fa+o -inmitte, mea 4 L. a a a m t m,. Ta av+ame ,,m. 6 w w r. + w a e w wvs saawwai= n i 6> w.ew s u i w a.y s a pie e i a w ui s w w sv w s si i sig v f4a 4. A ,,..,aA .kama 4La ..1..a

1. 1-m 4

m Ja 24o --ama /e1 wi wwi su wiswussww

wavvw, viiw w u s u w f a s.iy u w w ya ave s wy swwi w gwy

. m,1._ 4 a A 4m+a m ta 44o m

mb4ma, J.

,,,mmA. mea .44L +Lm u s a n e i s y., sie w w w u r w w. n e w w n a sii m asw .uessiuwww issww ya swa a sj i tm,1 1 a _. 2 m m 4L m,LalA,. s a s vw i nny wir. wsievius. . id +w 9, Ann--, wo.f.

2114am, it 2,,...

+L4 2, .Lmoa 1 Itt fr 1as,+ m mm g.j uwus= w vvv eu w s a ui s i a a vis usi assuw

m. i e u w is uuwww

1. AW.a f.

4. L a U f. t' U.

4.,s m

4. i. m.w., k a l.A

._.,m. . m. 4 L L ..a.1A Ui. f.* U. T.. ne .~ .m is .i. imi .~ u i . u u m J..- !. +,.. 4 L. ma. 4. L. . u rn. f I.tu y,. 2..a 4 + o. , uw inw.i u .m. si m. . i., y. s f r. i. w,.,, 4. L,, ino 19 m m.w iii,f.t 41 1 4. a,

1. s,,,,u, - e k. u, 4

2.,.

L,m..m m ai a- ,m .iu ...i..... ii. us. w v. n i nY,. .a f. 4La .. - s i. =iw., L..a 1. w

4.,, f,

.. m u 1. wA.a

1.,..._am.+.

U. f r* U., 4L A fAU s, wim .w ..u. u - ..m,i.a m 4 4 u,

4. k.. u m, m

6 L,s = u rn f t tu y

d. a. m.44.o, y i s i. i u mim i i

u .m ..i s i m,

f. r.,ne.,,

4. L - m,, i n. _,m.

m.w i.,, t _,, 4..- m.,.- 4...a 4L+

4..,

km,m g .w. .iu ...u. u i, s u.i i .~ v.iu, ..~.. _ i 1W t

4. L a U.. t. w* U. i., 4..,, L + k. m,a, L a 1, A, m._. m. 1, A,.a m. i.,o r

e.i u,,s n,,nn n .+. .a. .~ wi w., i m, us u imi

p. 4., 4 4,,o m,+ Lam,

e. k. m -

f_nD m m,t.a m.4 4.,o. s i i u.i m m u r i iwn i between de ~hw.m...ere:mayJ. %ds ussuesioM,e.w,essiextremetimporf... mymance;or ww w wm m.-m% e Un importanceRfo@vhi chWMEDIUNiorit0W!priod tilinabbe appropriateMbasedfo@c6nsiderationiofdtheWalue4mpact rel sti oni as ?wel l ?as. isafeti.lsign i, fi c_a. d..t mas s.isd_ida.tedHH nch m aEHIGH;prioritysistassigne L oran11 m Figu re~11p~si no fisafet%sisnif1 Esnce k NThif t&eshol d ?shbwMs on:thesba thilchartM s7aYcore%eW dansge7freq6e6cyQCMCDE)nedsstibnT6f si nificancel.l.rs~Ath~anith~elth~reshold sfo.atidfWit.hW~hafsti,~^* 10WpeWe. acto eaissiForYandisues soci g . ower t rtaTHIGH:prio. n ~y;but .~ r i10foflthit?thfesholdf(WrCDFsfl10%ier2RY)1 he-at leastdicatesfasMEDIUMfpriority9 b t. n. sregardlen_,f;c ; trade,4 ch=artsin sswo ostt offs?AtttheAoir4istend?ofnhe a scissa#thelpHoritiirask ndidated fispalssis; DROPifo6MIC0Fsbul owfl0% ped RY$ EC6st tra deaffs l enterf~i n_i theY10%f6.11_0% p_eB._RYEC#m.D_E_&angha_s~ C r. discussedjinise tiongckbelow<s i 04_/ _22/93 22 NUREG-0933 1

l Revision 4 A distinction has been maintained.between 1.0W and DROP issues. i Although neither_ is con'sidered further for current -rea'etors, the Commission believes that, foriadvanced reactors, LOW-priority issues should be considered:in the. design cf advchced rcccior ;, whereas DROP -issues are.of such 1ow consequence that they need not be consi_dered.' The abscissa' on the' Figure 1 chart pfovides a nieasurel6f(the L 7 issue's estimated: safetyL significance..in terms of:the change'in core-me44<!amage frequency attributable toLresolutionf of the issue. : This is often:the most useful. safety.' significance ~ measure.In GSIlpri oritization,.' though l for b some :i s sues, other measures may be Vequired or appropriate. : For example / a measure based oniradiological. consequences (probability _ averaged over;the' remaining;reactorL.: life)fis-used when the l issue under consideration involvesicontainment~: bypass!or relatestojcontainment.: performance lorother: features.or[ actions toimitigate thel rsdiologicel? consequencesiof. a lcoreimek damage. : Also',1tne; thresholds-may:need td:accommodateRthe_ _ possible influence of themumbertofsreactorsi:affectedlonsthe, therefore, repeated in: Figure"2:withiauxiliarpsabscissae ' Dis, appropriate priority' ranking. ?The" simple chartiof; Figure:;1 "~ ~ providing additional 7measuresiofssafetyisignificance. :Thsse are " used when thel principal iabsci ssa ti siinappl icabl e or! when~as auxiliary abscissa leads to"a'higheripriority indication):. Thus,. the' absc1ssae::for. totall effect C onTall:1 plants *come: into effect when more thanC30! plants :are'affected. " (c) Impact-Value Ratio Thresholds Wh'enithe 'safetiL:significanseTisiin'thiiintirmediateirange discussed above, ci.e!, GMFCDF betweenT10$ and110$per RYdst between 0.1)and110% of the : threshold lforfaiHIGHiriorit9,ithe impact /value'ratiou(R)fLis taken into account;in:theiranking indicatedby;thelcharti(Figurel1);.:Thislisidonelas*fol_.lowsii (1)1 In th'e rangs 6f;11tb"10%?6f th6TthFesh61diforTa:HIGH priority,thefindicated:prioritifisMEDIUM::if!Ris;bsisw 51,000/ person-rem. Otherwise:thefindicated priority 1is DROP. ~ (2) In!the~ range'of'0.136~1Fof'theH'IGfthresh'61dVths indicated priorityTis LOW or DROP, depending en whetheFR is below or'above-$1,000/ person-rem. i 04/22/93 23 NUREG-0933 P

i 1 IMPACT /VALUET ~ ?LEGENDin $/ PERSON-REM ~ PRIORITY- .: H = =4 HIGH - > 1,000f D; D- .Di M.- .H ! M 4 MEDIUM: L'L-- LOW '1,000/

D i= : DROP '-

-<:1,000- .DL ts 'M iMt. f H 1: l 110 7 l107 [10? 110y ~ ^ ~^ LA CDF:-per RY; .3Lxt104 L3fx110 N d..x110E 73 ^:'k?10'..',7 "'~' n YCDF]per;iYearf(Tokallj All? AffEAtAdl Reactibis)j ]. ' _[ 110Y - 210Y

d6Y dd'$

YPeEson-Rsm/Rektor'(OffAtte)/ i3ANO$ l3)x'109 53%20I T3(xdOY M PSrs6n-Rem [(Tod1? df fsits[ Al.1[ Affestid[RiactArd ~ ~ Figud 2 ? PFi6~ritElihEt hE3ithTAiixilliWAbsnii~ sis ^ 5. Other Considerations The formula-based rankings represent the primary concern of the NRC: public safety. The secondary concern is the impact on licensees, evaluated in terms of cost. However, the tentative priority rankings are subject to the limitations of an often incomplete and imprecise data base and to possible distortions due to the nature of the necessarily highly simplified quantitative formula underlying them. (Thi is the principal nasen-for c:t:bli:hing ice thrc: held v:1ce: for the LOW :nd DROP eategorie:.) Special situations with respect to some issues may cause added difficulty in priority assignment. While the formula-based tentative rankings must generally indicate that the safety significance is sufficient to justify NRC action, other considerations not adequately reflected, or not reflected at all, in the numerical formula are often needed to corroborate or adjust the results. Decision-making is helped by explicit identification of such other considerations and explanation of how they bear on the resulting final priority ranking, whether the effect is one of corroborating or of changing the estimates. Listed below are some factors that may be important in arriving at a sound priority ranking and may lead to adjustment of a tentative, formula-derived ranking. Possible effeets of occupational doses, averted plant-damage costs, and uncertainty bounds [(a)(1), (a)(2), (a)(3), and (b)(1) below) require particularly careful consideration for all issues. The factors listed are not considered all inclusive. Others thought significant are discussed 04/22/93 24 NUREG-0933

and, when practical, quantified appropriately in the overall rierit score :nd it; iisantifiedirliklsignificihesimea5&rifiddIispictf~iiliiih"itT6 anditheiriassociated"6ncertainties. "Sometimes7theFs~ ire special~ ^~~~ consideFations that are quite specific to an issue or some aspect of it. The partial list of other factors is listed below. IFshohldfbs3 odd inlii sssil66uld TFiciiViTT HIGH i pri ohi tisnli thit fis?detiimihfWetiSE?jei aistojsafeti;apejiv_en; con)J deratioK{~ ~ thosefof;thelfactorsithat (a) Special risk and cost aspects not included in or potentially masked by the numerical formulas: (1) The net change in occupational doses i=plicit in EdfQfiyy implementing the current versus the proposed requirements;

100, n n r:di:1 gie:1 :: cup tion:1_h:::ed; inherent in, er affected by, the prep :cd re:Clution:.J (2) Any significant non-radiation-related occupational risk pffjetedibKthfR@6fedjejjlstMsi (3) herted :::t of pl:nt d:::ge frc= the p :tulated :: identy (43) Loss or severe degradation of a layer in the defense-in-depth

'~ concept (e.g., one mode of core cooling or containment cooling). (53) Issues for which solutions of widely differing costs may be applicable to different classes of plants or various plants are otherwise affected in vastly different ways. (b) Factors related to uncertainties stemming from an incomplete or imprecise data base for the priority formula: (1) Uncertainty bounds, imbalance in uncertainty factors, certainty of cost to fix versus uncertainty that safety is really improved and the true extent of such improvement. (2) Situations where uncertainty is extraordinarily large (in accident probability, consequences, or cost, or any or all of these). (3) Problems which are ill-defined and problems for which solutions are not evident so that at least the resources necessary to understandtheproblemareassignedl (4) The potential for a proposed change to affect more than one accident or transient sequence, thus affecting risk to a greater or lesser degree than assessed in the description of the issue; notably, the potential for a new safety decrement, or increase in risk, due to unidentified effects of a proposed change, or addedcomplexity,orforotherreasonsy (5) Circumstances imparting unusual significance to accident consequences (such as ingestion-pathway effects) or mitigating measures (such as evacuation} that are not directly included in the public dose calculations; $4/22/93 25 NUREG-0933

l (6) Potential for human intervention, using available equipment. {c) Perception; :nd judgment: that-eennet (er c:nnet re:dily) bc quantified: (1) Public cencern bcut : particular i::uc, er :pect:1 Cc=i::ica cr Ocngres;ien:1..ncern (27) Acute knowledgeable professional controversy concerning the importance of an issue or modes of dealing with it. (ds) Change with passage of time: yJ'CWiffifef4EenisTFs6iiisil7sE651T6sT65Hif6FFMIWe7f ~sR ~~'pridriti zati o6MThel'e ffectN i f fa'nyNon'ithe t pri oritiMankt oN ad,ditiohalj20MaQQperatJ@3houldIbejehsratelfytaileQj (M) Potential substantial deterioration of the v:1ue/iapaetl#16Qjj]Is ratio while awaiting regulatory resolution (e.g., a potential design fix that is inexpensive to apply before construction, much more expensive after the plant i is largely built, and extremely expensive and problematical to apply to an operating plant)? (23) The amount of resources already spent on an issue, and how close to completion it may be; the value of continuity in efforts to resolve an issue! (Bf) The span of time predicted to resolve an issue and imphment the resolutiong (4$) The clarity of an " issue" and the objectivity with which it is currently defined?s' (PPerhaps additional research effort is necessarytoidendYya5ddefineaspecificriskreductionof interestj[) (66) Change of perceptions (of safety importance or value/ imp;ct b ret?Vilue relation or some special issue-peculiar factor) in rse of time. Generally a ations of large doubt or conflicting indications, the highest priority rank reasonably consistent with the nature of an issue is assigned. 1hus, where no solution is evident, assignment of a priority consistent wtth the safety significance of the issue may lead to a search for resolution or mitigation at an acceptable cost. Generally, should un-certainties narrow or perceptions change in the course of time, the priority rankings can be reexamined in the light of new developments and retained or changed. When different classes of plants are expected to be very differently affected by a potential resolution, the priority assign-ment is governed by the class of plants for which resolution is most worthwhile and urgent. (R.esolution in such cases can involve a new requirement for some class of plants and no action for others.) Where resolution differs for different classes of plants, differing priorities may be assigned. @/2Q9) 26 NUREG-0933

i 6. Concludina Remarks The criteria and estimating process on which the priority rankings are based are neither rigorous nor precise. Considerable application of professional judgment, sometimes guided by good information but often tenuously based, occurs at a number of stages in the process when numerical values are selected for use in the formula calculations and when i other considerations are taken into account in corroborating or changing a priority ranking. What is important in the process is that it is l systematic, that it is guided by analyses that are as quantitative as the situation reasonably permits, and that the bases and rationale are explicitly stated, providing a " visible" information base for decision. I The impact of imprecision is blunted by the fact that only approximate rankings (in only four broad priority categories) are necessary and sought. l IV. RESULTS OF PRIORITIZATION The results of the prioritization and resolution of all issues contained in i this report are summarized and tabulated by group in Table III. In addition, a listing of those issues that affect operating and future plants is given in Appendix B. This appendix reflects the results of prioritization and resolution and only includes: (1) issues that have been resolved with new requirements [ NOTE 3(h)]; (2) USI, HIGH and MEDIUM priority issues that are being resolved; (3) nearly-resolved issues (NOTES 1 and 2); and (4) issues that E sfidI(5HisiussiOsitTsiifiiBFisslilidisiiWiistIFeiluiriiioidsift_y,et known (NOTE 4)iSUt are scheduled for prioritization and whose impact is no wigntsffdmiuitemenslfoyjfutsipligsfu)! eridegelog!nge gj-~~ ort 6jis?istii fiii~ts d l REFERENCES-1. SECY-81-513, " Plan for Early Resolution of Safety Issues," August 25, 1981. 2. NUREG-0371, " Task Action Plans for Generic Activities (Category A)," U.S. Nuclear Regulatory Commission, November 1978. 3. NUREG-0471, " Generic Task Problem Descriptions (Categories B, C, and D)," U.S. Nuclear Regulatory Commission, June 1978.

11. NUREG-0803, " Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants," U.S. Nuclear Regulatory Commission, (1st Edition) November 1975, (2nd Edition) March 1980, (3rd Edition) July 1981.

16. WASH-1400 (NUREG-75/014), " Reactor Safety Study, An Assessment of Accident itisks in U.S. Comercial Nuclear Power Plants," U.S. Nuclear Regulatory Commission, October 1975.

44. NUREG-0705, " Identification of New Unresolved Safety Issues Relating to Nuclear Power Plant Stations," U.S. Nuclear Regulatory Commission, March 1981.

l r 6Q22/93 27 NUREG-0933 j i

48. NUREG-0660, "NRC Action Plan Developed as a Result of the TMI-2 Accident," U.S. Nuclear Regulatory Comission, May 1980.

64. NUREG/CR-2800, " Guidelines for Nuclear Power Plant Safety Issue Prioritization Information Development," U.S. Nuclear Regulatory Comission, February 1983.

70. NUREG-0348, " Demographic Statistics Pertaining to Nuclear Power Reactor Sites," U.S. Nuclear Regulatory Comission, November 1979.

98. NUREG-0737, " Clarification of TMI Action " m Requirements," U.S. Nuclear Regulatory Commission, November 1980.

186. NUREG-0510, " Identification of Unresolved Safety Issues Relating to Nuclear Power Plants," U.S. Nuclear Regulatory Comission, January 1979. 197. Code of Federal Regulations, Title 10, Energy. 210. NUREG-0885, Issue 2, "U.S. Nuclear Regulatory Comission Policy and Planning Guidance," U.S. Nuclear Regulatory Commission, January 1983. 387. NUREG-0410, "NRC Program for the Resolution of Generic Issues Related to Nuclear Power Plants," U.S. Nuclear Regulatory Comission, January 1978. 393. "TMI-2 Recovery Program Estimate," Rev. 1, General Public Utilities Corp., July 1981. j 603. NUREG-0985, "U.S. NRC Human Factors Program Plan," U.S. Nuclear Regulatory Comission, August 1983. 1188. SECY-83-221, "Prioritization of Generic Safety Issues," June 7, 1983. 1189. Memorandum for W. Dircks from S. Chilk, "SECY-83-221 - Prioritization of Generic Safety Issues," December 9, 1983. i 1190. Federal Register Notice 43 FR 1565, " Program for Resolution of Generic Issues Related to Nuclear Power Plants," January 10, 1978. i 1191. Fedtral Register Notice 54 FR 24432, " Program for Resolution of Generic Issues Related to Nuclear Power Plants; Policy Statement," June 7,1989. 1192. Memorandum for R. Fraley, et al., from E. Beckjord, "RES Office Letter No. 1, ' Procedure for Identification, Prioritization, and Tracking of the Resolution of Generic Issues,'" December 3,1987, (Rev.1) March 22, 1989. 1193. Memorandum for R. Fraley, et al., from E. Beckjord, "RES Office Letter No.2, ' Procedures for Obtaining Regulatory Impact Analysis Review and Support,'" November 18, 1988. 1194. Memorandum for R. Fraley et al., from E. Beckjord, "RES Office Letter No. 3 Procedure and Guidance for the Resolution of Generic Issues," May 10, 1988, (Rev. 1) December 21, 1988, (Rev. 2) March 27, 1989. 0J/22/93 28 NUREG-0933

1195. NUREG-1251, " Implications of the Accident at Chernobyl for Safety Regulation of Commerical Nuclear Power Plants in the United States," U.S. Nuclear Regulatory Commission, (Vol.1) April 1989, (Vol. 2) April 1989. NUR.EG/CR.I3568RfA H. ion;L_De. c.e. m_b.E..v, iTE.Im,..isiE.Usu ih. d. S56E..>.f6 n X n < PAllI IN-lliN ~

9. 7.. 0., H.a.u.

w vs ~r e e Regu_.l_ato.r.<ya.i c._o_mm...i s.-._.;._% er_<19_8_3_;. ~ 9 ~ a 1473 EMemoraiWGEIf61F7CTiy15FIffiiiTsXcM ik7]jjSECT1 92I0iM7faiip~1 ement afi3H"f~D i -._f?of..d t.~h.e_lSaf.etyiG.o.~alsWJ. une. ?.15#~;19. 90.._1s j - " ~ ~ ^ ' ~ ~ ~ " ~ ~ ~ ~ ~ ~ ^ " ~ ^ ~ ~ ~ " R ~ ~ ~ h ~; h i l I 1 i t l i ? e 4 i 0 I e 4 4 i f t t h I 01F22.793 29 NUREG-0933 f I. i t

Aa7 i_._._# ss .,.-w.m. ..m.- %e.. u _.a. l l i l l APPENDIX _C 1 W ICAL~ THRESH 0LDS".FOR PRIORITY RAK ING USED IN PRIORITIZATimS~ COMPLETED BEFORE OCTOBER T F 1992 i i l i 1 l l 1 I i i l i 6 6 l b l '1 l ( 2 l A l l 1 1 1 4 i l i 1

i 4 l [ l TABLE 1 l l 1 RISK THRESHOLDS (a) The priority rank is always HIGH when any of the following risk (or I risk related) thresholds are estimated to be exceeded (or when extraordinary uncertainty suggests that they may well be exceeded): i ) (1) 1,000 person-rem estimated public dose per remaining reactor lifetime i (2) 50,000 person-rem total estimated for all affected reactors for j i their remaining lifetime (e.g., 500 person-rem / reactor for 100 t reactors) (3) 10"/ reactor-year large-scale core-melt i (4) 5 x 10"/ year large-scale core-melt (total for all affected i reactors) (b) Always at least MEDIUM priority: 10 or more percent of the always-HIGH criteria (c) Always at least LOW priority: 1 or more percent of the always-HIGH Criteria i l (d) Never hiaher than MEDIUM priority-i Less than 10% of the always-HIGH criteria i (e) Never hiaher than LOW priority: f Less than 1% of the always-HIGH criteria I (f) Aways DROP category: i s Less than 0.1% of the always-HIGH criteria f i f 1 i; e I i l f d l l b n

Legend: H =HIGH priority I D L M H H M = MEDIUM priority L = LOW priority D = DROP 3,000 2

• s!

D L M M H m a: I 8 3 2 ? vi 1# 2 d R B E E D L L M H .n y E g E e 3 10 D D L M H if 10' 19 10" Man-Rom / Reactor 5x10' 6x10' 6x10' 6x10' Man-Rom (Total, All Reactors) 4 10 10* 10 Core-Melt /RY 8 10 8 8 6x10* Core-Melt /Yr. 5x1C 6x19 6x10 Change in Risk -l 1 l -.-.--,4 .m .m -....,_.....m...s... g.., m..--.-.+,,,,n,,,,.. ms..,_r.y.....,w._c---, ew e--. *

-_+,n. c.--- -,n.-.-...u -. - ~ -~..- + <. >. -~v .2a-~n.--.a--ntns-a ---~ ~ w +=w.-mu..>a, .w+.u.=--.-w.,au.u n - u-- s a-p )'- k 1 i-b a i i ) 1 ? i I d l l. d i o i 1 i n f 4 !~ J l 8 i I 1 I ' l 4 h 1 I l 1 i i l l-I I i l 4 ? i l I I i I I P I B 9 --..m't.we~ - ~ ~. O----...-.- e .~... ~ ..--e-. .r.~. svm--,~~,.

t i i 1 k l i ENOLOSURE 2 t A. COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NEW REQUIREMENTS (11/33 TO 9/92) B. COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NO NEW REQUIREMENTS (11/83 TO 9/92) C. COMPREHENSIVE LISTING 0F 64 GSIs RESOLVED UP TO 9/30/92 i i 1 1 s ? + i

ENCLOSURE 2A COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NEW REOUIREMENTS (11/83 TO 9/92) A RISK (man-rem) COST ($M) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACll PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY 1 1.A.2.6.l(l) 130,000 2,210 H 17,000 M 2 I.A.4.2(1) 150,000 1,010 11 6,733 M 3 I.A.4.2(4) 150,000 1,010 H 6,733 M 4 II.B.8 1,600 10 H 6,250 M 5 B-10 750,000 39 H 52 11 6 HF1.1 H' 7 43 65,000 19.7 H 303 M 8 87 52,000 8 H 154 M 9 93 96,000 11.6 Il 121 M 10 94 6,600 1.2 H 182 M 11 99 20,000 2.7 H 135 M 12 128 (A-30) 530,000 14.6 H 28 H 13 130 9,700 0.05 H 5 M 14 I.G.2 25,800 240 M 9,302 D' 15 II.E.6.1 30,000 68 M 2,267 M M 3,022 D* 16 51 22,000 66.5 17 70 31 0.27 M 8,77.0 D' Priority Ranking Based on Other Considerations Page 1 of 2 .. - ~.. -

_= ENCLOSURE 2A (CONTINUED) COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NEW RE0VIREMENTS (11/83 TO 9/92) NOTES: 1. The resolution of Issue I.G.2 resulted in changes to SRP Section 14 and the staff's Inspection and Enforcement Manual. No backfit was warranted on operating plants. 2. The resolution of Issue 51 was the issuanca of GL 89-13 which covered a broader scope than was originally identified. GL 89-13 was not justified on a value/ impact basis, but was deemed to be compliance. 3. The resolution of Issue 70 resulted in the issuance of GL 90-06 which required TS revisions at operating PWRs with PORVs and block valves. For future plants, revisions to SRP 3.2.2, 5.2.2, and 5.4.7 were proposed. i Page 2 of 2 _--,,,i. --~~_..r_.,._..., ..-.we -m, ..-,.-,.-r,.y. _, _ --r_ -,-.m,y,,. , ~., - - -.- 6--4.. ..,-c-, .r,,-%.,..-,-

ENCLOSURE 28 COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NO NEW RE0VIREMENTS (l1/83 TO 9/92) A RISK (man-rem) COST ($M) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACH PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIOP,ITY 18 I.A.2.2 122,000 691 H 5,660 M 19 I.A.3.3 16,000 1,19F H 74,750 D 20 I.F.1 li' 21 II.B.6 40,500 4.02 H 99 11 22 II.C.1 12,000 13.2 11 1,100 0 23 II.C.2 79,000 82.8 H 1,048 M 24 II.C.4 267,100 558.7 H 2,092 M 25 II.E.4.3 35,000 159.8 H 4,566 M 340.5 H 532 H 26 III.D.3.1 640,000 27 IV.E.5 80,000 74 H 925 M 28 C-8 10,900 15.5 H' 1,422 0 29 HF.1.2 H' 30 liF.1.3 IT 31 HF.4.1 H' 32 HF.8 310,000 12,318 H 39,735 H 33 29 450,000 387 H 860 H i Priority Ranking Based on Other Considerations i Pa9e 1 of 3

ENCLOSURE 2B (CONTINUED) COMPARATIVE PRIORITY RANKING 0F HIGH AND MEDIUM PRIORITY ISSUES RESOLVED WITH NO NEW RE0VIREMENTS (11/83 TO 9/92) A RISK (man-rem) COST ($M) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACH PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY 34 101 1,000 1 H 1,000 M 35 113 430 6 H 13,953 0 36 115 5,500 1.12 H 204 M 37 121 H' 38 122.2 6,500 3 H 462 M 1 39 125.11.7 1,300 1.18 H 908 L 40 134 H' 41 1.A.2.6(4) 7,100 43.2 M 6,050 D 42 I.A.2.7 26,200 402.4 M 15,359 D 43 1.A.3.4 10,100 490 M 48,514 0 44 I.B.I.l(l) M M 45 I.B.I.1(2) 50,400 66.1 M 1,312 M 46 1.B.1.l(3) M M 47 1.B.I.l(4) M M 48 I.C.9 210,000 456 M 2,171 M M 1,655 0 49 1.D.4 840 1.39 Priority Based on Other Considerations Page 2 of 3.

ENCLOSURE 2B (CONTINUED) COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY ISSUES RESOLVED WITH NO NEW REQUIREMENTS i (11/83 TO 9/92) A RISK (man-rem) COST ($M) IMPACT / VAulE OLD SCORE NEW GSI NO. All PLANTS EACH PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY 50 II.A.1 6,000 100 M 16,667 M 51 II.E.2.2 41,000 41 M 1,000 M 52 III.A.3.4 18,000 8.5 M 472 M 53 A-29 24,000 725 M 30,033 D 54 A-41 M' 55 8-5 5,200 10.5 M 2,019 D 56 B-26 373 1.2 M 3,217 D 57 B-54 4,700 208 M' 44,255 D 58 B-58 4,000 19.05 M 4,763 D 59 C-11 66,000 723 M 10,955 M 60 12 850 64 M 75,300 D 61 61 6,300 36.6 M 5,810 D 62 82 700 1 M 1,429 D 63 135 M' 64 151 12,000 13 M 1,560 D i Priority Ranking Based on Other Considerations Page 3 of 3

ENCLOSURE 2C COMPREHENSIVE LISTING OF 64 GSIs RESOLVED UP TO 9/30/92 GSI NO. TITLE I I.A.2.6(1) Revised Regulatory Guide 1.8 2 I.A.4.2(1) Research on Training Simulators 3 I.A.4.2(4) Review Simulators for Conformance to Criteria 4 II.B 8 Rulemaking Proceeding on Degraded Core Accidents 5 B-10 Behavior of BWR MARK III Containments 6 HF1.1 Shift Staffing 7 43 Reliability of Air Systems 8 87 Failure of HPCI Steam Line Without Isolation 9 93 Steam Binding of Auxiliary Feedwater Pumps i 10 94 Additional Low Temperature Overpressure Protection for Light Water Reactors 11 99 RCS/RHR Suction Line Valve Interlock on PWRs 12 123 (A-30) Electrical Power Reliability (A-30: Adequacy of Safety-Related DC Power Supplies) i 13 130 Essential Service Water Pump Failures at Multiplant Sites 14 I.G.2 Preoperational and Low-Power Testing: Scope of Test Program m -4 .,w.

ENCLOSURE 2C (CONT) COMPREHENSIVE LISTING OF 64 GSIs RESOLVED UP TO 9/30/92 GSI NO. TITLE 15 II.E.6.1 In-Situ Testing of Valves: Test Adequacy Study 16 51 Proposed Requirements for Improving the Reliability of Open Cycle Service Water Systems 17 70 PORV and Block Valve Reliability 18 I.A.2.2 Training and Qualifications of Operations Personnel 19 I.A.3.3 Requirments for Operator Fitness 20 I.F.1 Expand QA List 21 II.B.6 Risk Reduction for Operating Reactors at Sites with High Population Densities 22 II.C.1 Interim Reliability Evaluation Program 23 II.C.2 Continuation of Interim Reliability Evaluation Program 24 II.C.4 Reliability Engineering 25 II.E.4.3 Containment Design: Integrity Check 26 III.D.3.1 Radiation Protection Plans 27 IV.E.5 Assess Currently Operating Reactors 28 C-8 Main Steam Line Leakage Control Systems

a I l ENCLOSURE 2C (CONT) COMPREHENSIVE LISTING OF 64 GSis RESOLVED UP TO 9/30/92 GSI NO. TITLE 29 HF.1.2 Engineering Expertise on Shift 30 HF.1.3 Guidance on limits and Conditions of Shift Work 31 HF.4.1 Inspection Procedure for Upgraded Emergency Operating Procedures 32 HF8 Maintenance and Surveillance Program 33 29 Bolting Degradation or Failure in Nuclear Power Plants 34 101 BWR Water level Redundancy 35 113 Dynamic Qualification Testing of large Bore Hydraulic Snubbers 36 115 Enhancement of the Reliability of Westinghouse Solid State Protection System 37 121 Hydrogen Control for Large, Dry PWR Containments 38 122.2 Initiating Feed-and-Bleed 39 125.II.7 Reevaluate Provision to Automatically Isolate Feedwater from Steam Generator During a Line Break 40 134 Rule on Degree and Experience Requirement 41 I.A.2.6(4) Training and Qualifications of Operating Personnel: Operator Workshops 42 I.A.2.7 Accreditation of Training Institutions -m a -. = -. e e m m m

ENCLOSURE 2C (CONT) COMPREHENSIVE LISTING OF 64 GSIs RESOLVED UP TO 9/30/92 GSI NO. TITLE 43 I.A.3.4 Licensing of Additional Operations Personnel 44 I.B.I.l(l) Organization and Management Long-Term Improvements: Prepare Draft Criteria 45 I.B.I.l(2) Organization and Management Long-Term Improvements: Prepare Commission Paper 46 I.B.1.l(3) Organization and Management long-Term Improvements: Issue Requirements for the Upgrading of Management and Technical Resources 47 I.B.I.l(4) Organization and Management long-Term Improvements: Review Responses to Determine Acceptability 48 I.C.9 Long-Term Program Plan for Upgrading of Procedures 49 1.D.4 Control Room Design Standard 50 II.A.1 Siting Policy Reformulation 51 II.E.2.2 Research on Small-Break LOCAs and Anomalous Transients 52 III.A.3.4 Nuclear Data Link 53 A-29 Nuclear Power Plant Desgin for the Reduction of Vulnerability to Industrial Sabotage 54 A-41 Long-Term Seismic Program 55 B-5 Ductility of Two-Way Slabs and Shells and Buckling Behavior of Steel Containments 56 B-26 Structural Integrity of Containment Penetrations

i. e s s R t W n B e m n n i m i a p t m n u o P C n e l o I i 2 t 9 d a / n l 0 a u 3 s c / e I r 9 v i l k c O a r e T V a R M P d M U n f s A a o l R D o C E s e o S V E p c P L L m a t ) O T u p l u T S I P s e o N E T r u h s O R f i F t C o A l i ( s t l W I y l n i C S t l e f t 2 G i e p r n l w S e e E 4 i t v i R 6 b e n O s U a W i n S F i e a O O l R s n r r L e W t i T C G s R B n l N N s e e d E I t r d e d m e m T n u n h i a t S e l a t c e a I m i c t p L n a e y e A S i i F r t d c E a u i i s d i V t l l r s i n t I n a i g n s a n S o c a e I a A N C i F t B r E n n k o f H r a f I a n t o E e h o e g a R s c p r i r y P n e t m B s e t M e M n u e n i O d e P e D e l C n e m n G i d b o v s t i i s e L n m a C s e J o a i e s s V y e l c a s R R e t e I P A W S B S R B O w N 1 I 4 8 1 S 5 5 5 1 G C 2 1 2 3 5 B B 1 6 8 1 1 7 8 9 0 1 2 3 4 5 5 5 6 6 6 6 6 + l l l'

I J 4 I L I ENCLOSURE 3 ACRS LETTER DATED NOVEMBER 12. 1992 b L J h ? t

r l f OECy / 'o UNITED STATES NUCLEAR REGULATORY COMMISSION ACRSR-1501 'g -n I 0 -,E { ADVISORY COMMITTEE ON REACTOR SAFEGUARDS pgp WASHINGTON, D. C. 20555 v...../ November 12, 1992 l l Mr. James M. Taylor Executive Director for Operations U.S. Nuclear Regulatory Commission Washington, D.C. 20555 l

SUBJECT:

REVISED GUIDELINES FOR PRIORITIZATION OF GENERIC SAFETY ISSUES During the 391st meeting of the Advisory Committee on Reactor Safeguards, November 5-7, 1992, we reviewed a proposed draft Revision 4 of NUREG-0933, "A Prioritization of Generic Safety Issues." Our Subcommittee on Safety Philosophy, Technology, and Criteria considered this matter during a meeting on October 28, 1992. During these meetings, we had the benefit of discussions with representatives of the NRC staff, and of the documents, referenced. As part of the program for resolution of Generic Safety Issues (GSIs), the staff historically has attempted to prioritize the issues in order to appropriately focus resources. After considerable experience (9 years) in using this prioritization methodology, the staff has concluded that the conservatisms provide too much margin and that " resources appeared to have been devoted to resolving a large number of issues with no safety improvement resulting." The revised guidelines being proposed by the staff are intended to reduce the perceived excessive margins in the prioritization criteria, presumably so that a higher fraction of those-issues subjected to the full Regulatory Analysis (RA) would also require some regulatory action as a result of the RA. The staff's proposal is to modify the "prioritization formula" by increasing the risk-reduction thresholds by an order of magnitude (10Y) and to simplify the way in which costs enter into the priority ranking. We agree with the basic concepts that underlie a prioritization scheme based on risk reduction potential and impact /value criteria, but believe additional work is needed before the specific proposed modifications are brought to the Commission for approval. The proposed modifications are mostly arbitrary and do not have firm technical bases. We submit that the objective of such a prioritization scheme should be to essentially capture as many as l 9212010254 921112 PDR ACRS R-901

i i Pr. James M. Taylor 2 November 12, 1992 i possible of those issues for regulatory analysis that will result in some regulatory action (i.e., would pass the RA criteria) while i at the same time screening out as many issues as possible that i would not pass the RA criteria. This is not an easy objective to accomplish because, with any scheme approximating risk and costs, t some significant issues that would have required regulatory action will likely be lost (relegated to LOW or DROP priority) whereas l some number of issues that will not require any regulatory action will be prioritized to be given an RA. l The proposed modifications will surely result in a much higher percentage of " hits" but will also likely result in a higher number of issues being discarded that would have proven to have been significant if given an RA. We recommend that all of those GSIs that have already been given a I full regulatory analysis with the result being that regulatory action was called for (there are apparently 16 of these) be placed on the decision chart grid (impact /value vs. delta-risk) and that empirical boundaries be drawn for thresholds that would capture a]1 ) of these. For insight, it would be useful also to put on the grid j all the other already-screened issues. This empirical i determination of the thresholds will not guarantee optimization of + the process for future issues, but we think it would go a long way-toward removing the arbitrariness of the proposed thresholds presented in the draft document. i Sincerely, 4 PJ G 1 4 l Paul Shewmon Chairman i

Reference:

Memorandum dated August 5, 1992 (corrections dated August 19, 1992), from C. J.

Heltenes, Jr.,

Office of Nuclear Regulatory Research, for Raymond F. Fraley, Advisory Committee on Reactor j Safeguards,

Subject:

Request for ACRS Review of Revised Guidelines j for Prioritization of Generic Safety Issues, transmitting: f (a) Draft SECY paper for the Commission'from James M.

Taylor, I

Executive Director for Operations,

Subject:

Revised j Guidelines for Prioritization of Generic Safety Issues (Predecisional) (b) Draft Markup of Introduction Section, NUREG-0933, Revision 4, t "A Prioritization of Generic Safety Issues," August 5, 1992 l (Predecisional) t l I i P r i i

ENCLOSURE 4 STAFF RESPONSE TO !!/12/92 ACRS COMMENTS i

ENCLOSURE 4 b/ ,cro &~ 4* 3 UNITED STATES 3 Ys InE NUCLEAR REGULATORY COMMISSION o WASHINGTON, D.C. 205E6 April 28, 1993 Dr. Paul Shewmon, Chairman Advisory Committee on Reactor Safeguards US Nuclear Regulatory Commission Washington, D.C. 20555

Dear Dr. Shewmon:

In accordance with the ACRS recommendation of November 12, 1992, the proposed revision to the prioritization guidelines transmitted to the ACRS on August 5, 1992, was used to develop a comparison between the existing and proposed priority rankings for the 17 generic safety issues (GSIs) that have been resolved with requirements. These GSIs were given HIGH-or MEDIUM-priority rankings and scheduled for resolution after being subjected to the original prioritization guidelines developed by the staff and approved by the Comission and the ACRS in 1983. The results of this comparison are shown in, which includes all GSIs resolved between November 1983 and September 1992. It should be noted that the proposed prioritization guidelines were modified subsequent to the ACRS comments to reflect the current value of $1,000/ person-rem. Figure 1 displays this value which will be updated when a revised $/ person-rem value is approved by the Commission. t In addition to the 17 GS:s that resulted in new requirements, the other 47 already-screened GSIs that were resolved with no new requirements were subjected to the proposed revised guidelines; the results are shown in. The titles of all 64 GSIs considered in this evaluation are given in Enclosure 3. i The results summarized in Enclosure I show that 13 of the 17 HIGH-and MEDIUM-priority GSIs that were resolved with requirements would be ranked HIGH-or MEDIUM-priority with the proposed criteria. Three MEDIUM-priority issues that were resolved with requirements would be in the DROP category. One HIGH-priority GSI was ranked without quantitative estimates. An explanation of the disposition of these 3 GSIs is included in Enclosure 1. The 3 GSIs that would not be pursued (I.G.2, 51, and 70) are noted to have relatively low risk reduction potential (< 30,000 person-rem for GSIs I.G.2 and 51 and 31 person-rem / plant for GSI 70). In addition, the impact /value score (5/ person-rem) is greater than $1,000/ person-rem for each issue. On this basis, these issues are not considered significant and would have a marginal impact on public s&fety. The results surnkrized in Enclosure 2 show that 21 of the 47 HIGH-or MEDIUM-priority GSIs that were resolved with no requirements would be ranked HIGH-or MEDIUH-priority with the proposed c iteria. Eighteen of the GSIs that were

. resolved with no requirements would be ranked LOW or DROP. Eight of the 47 GSIs were ranked without quantitative estimates. Overall, using the proposed revision to the prioritization guidelines would have resulted in pursuit of the resolution of 43 of the 64 GSIs originally identified as HIGH-or MEDIUM-l priority. Your continuing interest in the ongoing revision to the prioritization guidelines is appreciated and the staff would be pleased to respond to any further ACRS recomendations on the subject. Original @MY Ames K.TayW James M. Taylor i Executive Director for Operations

Enclosures:

1. Comparative Priority Ranking of High and Medium Priority GSIs Resolved With Requirements 2. Comparative Priority R6nking of High and Medium Priority GSIs Resolved With Eg Requirements. 3. Comprehensive Listing of 64 GSIs Resolved up to September 30, 1992 cc: The Chairman Comissioner Rogers Comissioner Curtiss Comissioner Remick Comissioner de Planque SECY t

• See Previous Concurrence OFFICE: RPSIB/DSIR: RPSIB/DSIR: RPSIB/DSIR: D/DSIR : DD/RES NAME :*REmrit/bgj:*PNorian

• GMazetis
• WMinners:*CHeltemes:

DATE :11/24/92

11/24/92

11/24/92

3/2/93 : 3/17/93 OFFICE: D/RES

E M JT. lor :

NAME :*EBeckjord: a y)f/93: DATE : 3/18/93

a L ENCL 0SURE 1 COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NEW REQUIREMENTS (11/83 TO 9/92) T A RISK (man-rem) COST ($M) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACH PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY I I.A.2.6.1(1) 130,000 2,210 H 17,000 M 2 I.A.4.2(1) 150,000 1,010 H 6,733 M 3 I.A.4.2(4) 150,000 1,010 H 6,733 M 4 II.B.8 1,600 10 H 6,250 M 5 B-10 750,000 39 H 52 H H' 6 HF1.1 19.7 H 303 H 7 43 65,000 8 87 52,000 8 H 154 M 9 93 96,000 11.6 H 121 M 10 94 6,600 1.z H 182 M 11 99 20,000 2.7 H 135 M 14.6 H 28 H 12 128 (A-30) 530,000 13 130 9,700 0.05 H 5 M 14 I.G.2 25,800 240 M 9,302 D' M 2,267 M 15 II.E.6.1 30,000 68 M 3,022 D' 16 51 22,000 66.5 17 70 31 0.27 M 8,710 D' Priority Ranking Based on Other Considerations Page 1 of 2

ENCLOSURE I (CONTINUED) COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NEW REQUIREMENTS (11/83 TO 9/92) NOTES: 1. The resolution of Issue I.G.2 resulted in changes to SRP Section 14 and the staff's Inspection and Enforcement Manual. No backfit was warranted on operating plants. 2. The resolution of Issue 51 was the issuance of GL 89-13 which covered a broader scope than was originally identified. GL 89-13 was not justified on a value/ impact basis, but was deemed to be compliance. 3. The resolution of Issue 70 resulted in the issuance of GL 90-06 which required TS revisions at operating PWRs with PORVs and block valves. For future plants, revisions to SRP 3.2.2, 5.2.2, and 5.4.7 were proposed. l l l I Page 2 of 2 1

ENCLOSURE 2 COMPARATIVE PRIORITY RANKING 0F HIGH AND MEDIUM PRIORITY GSIs RESOLVED WITH NO NEW RE0VIREMENTS (11/83 TO 9/92) A RISK (man-rem) COST ($M) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACH PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY 18 I.A.2.2 122,000 691 H 5,660 M 19 I.A.3.3 16,000 1,196 H 74,750 0 20 1.F.1 li' 21 II.B.6 40,500 4.02 H 99 H 22 II.C.1 12,000 13.2 H 1,100 D 23 II.C.2 79,000 82.8 H 1,048 M 24 II.C.4 267,100 558.7 H 2,092 M 25 II.E.4.3 35,000 159.8 11 4,566 M 26 III.D.3.1 640,000 340.5 H 532 11 27 IV.E.5 80,000 74 H 925 M L 28 C-8 10,900 15.5 H' 1,422 0 29 HF.1.2 H' 30 HF.I.3 H' 31 HF.4.1 H' 32 HF.8 310,000 12,318 H 39,735 H 33 29 450,000 387 H 860 H Priority Ranking Based on Other Considerations Page 1 of 3

h .e 24 L 2 .h -a a e h ENCLOSURE 2 (CONTINUED) COMPARATIVE PRIORITY RANKING OF llIGH AND MEDIUM PRIORITY ISSUES RESOLVED WITH NO NEW REQUIREMENTS (11/83 TO 9/92) A RISK (man-rem) COST ($H) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACil PLANT All PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY 34 101 1,000 1 H 1,000 M 35 113 430 6 11 13,953 0 36 115 5,500 1.12 H 204 M H' 37 121 38 122.2 6,500 3 H 462 M 39 125.II.7 1,300 1.18 H 908 L 40 134 H' 41 I.A.2.6(4) 7,100 43.2 M 6,050 0 42 I.A.2.7 26,200 402.4 M 15,359 0 43 1.A.3.4 10,100 490 M 48,514 0 44 I.B.I.I(1) M M 45 1.B.1.l(2) 50,400 66.1 M 1,312 M 46 I.B.I.l(3) M M 47 I.B.I.l(4) M M 48 I.C.9 210,000 456 M 2,171 M 49 I.D.4 840 1.39 M 1,655 0 Priority Based on Other Considerations Page 2 of 3 '

ENCLOSURE 2 (CONTINUED) COMPARATIVE PRIORITY RANKING OF HIGH AND MEDIUM PRIORITY ISSUES RESOLVED WITH NO NEW REOUIREMENTS (11/83 10 9/92) A RISK (man-rem) COST ($M) IMPACT / VALUE OLD SCORE NEW GSI NO. ALL PLANTS EACH PLANT ALL PLANTS EACH PLANT PRIORITY ($/ man-rem) PRIORITY 50 II.A.1 6,000 100 M 16,667 M 51 II.E.2.2 41,000 41 M 1,000 M 52 III.A.3.4 18,000 8.5 M 472 M 53 A-29 24,000 725 M 30,033 D 54 A-41 M' 55 B-5 5,200 10.5 M 2,019 0 56 B-26 373 1.2 M 3,217 0 57 B-54 4,700 208 M' 44,255 0 58 B-58 4,000 19.05 M 4,763 0 59 C-11 66,000 723 M 10,955 M 60 12 850 64 M 75,300 0 61 61 6,300 36.6 M 5,810 0 62 82 700 1 M 1,429 D M' 63 135 64 151 12,000 13 M 1,560 0 Priority Ranking Based on Other Considerations Page 3 of 3

ENCLOSURE 3 COMPREHENSIVE LISTING OF 64 GSIs RESOLVED UP TO 9/30/92 GSI NO. TITLE 1 1.A.2.6(1) Revised Regulatory Guide 1.8 2 1.A.4.2(1) Research on Training Simulators 3 I.A.4.2(4) Review Simulators for Conformance to Criteria 4 II.B.8 Rulemaking Proceeding on Degraded Core Accidents 5 B-10 Behavior of BWR MARK III Containments 6 HF1.1 Shift Staffing 7 43 Reliability of Air Systems 8 87 Failure of HPCI Steam Line Without Isolation 9 93 Steam Binding of Auxiliary Feedwater Pumps 10 94 Additional Low Temperature Overpressure Protection for Light Water Reactors 11 99 RCS/RHR Suction Line Valve Interlock on PWRs 12 123 (A-30) Electrical Power Reliability (A-30: Adequacy of Safety-Related DC Power Supplies) 13 130 Essential Service Water Pump Failures at Multiplant Sites 14 I.G.2 Preoperational and low-Power Testing: Scope of Test Program

re t s a e i W t i e s c n iv e r D e S no i e t lc a l y u 2 C p 9 / n o P 0 e 3 p / O hg 9 m i f O o H ar T y l h g P t e t o U i n i r l n w P i o D E y b s s n V E d a r e o L L u i e t i O T t l P i t S I S e S a ) E T R s u T N R y n t l O c e o a a s m v m C s a h i I u t t s a E e ( S q a r r t 3 G e g r o g y k s s d n e t o t c r y 4 A i p c r i e o S E 6 v y O s a P l h t RU t o t s e i C c l F s r i f e R n b a o SO O e p l o n o a y e r i t g i i t R t L T m G I b s i n t l i n C a n F i a e r s g o N N E s r i o t u R g n n C I T e o l i r a l e a i S v f e t o r a m g t l t e I l R a t e v i n n P a g L a s c a p E r i I r a V t e i r O e r n e k E n v f e y t e o p a O e V f e l i p r t n e n i I o m a l O o i I n g t L S e V a f l i i c y N g r u r i f g s e l e E n i k Q o t n b o n e t t n i u c f s o a E D o n i H E t q o d i i i n r e L R s e l n s L t l o y t P r P e R B a t c e i t n r m M T n A u R t i e n u a O d d g e Q d a l m o C e C u es n n m e m u i n i t t sm a i r d R i n b i t s S i oe n i n r i a a a s S pt Y i u a k e t i t i e n os R a q p s t n l n d s i n ry O r e x i n o e o a s a I PS P T R E R I C R C R A M 1 3 1 3 2 3 6 2 4 4 5 O 1 N 6 2 3 D. 1 B. C. C. C. E. E. E. A. A. F. I I 8 S I I I I I I V G I 1 0 I 5 7 1 1 1 I I I I I I I C 5 6 7 8 9 0 1 2 3 4 5 6 7 8 1 1 1 1 1 2 2 2 2 2 2 2 2 2

t ENCL 0SURE 3 (CONT) COMPREHENSIVE LISTING OF 64 GSIs RESOLVED UP TO 9/30/92 GSI NO. TITLE 29 HF.1.2 Engineering Expertise on Shift 30 HF.1.3 Guidance on Limits and Conditions of Shift Work 31 HF.4.1 Inspection Procedure for Upgraded Emergency Operating Procedures 32 HF8 Maintenance and Surveillance Program 33 29 Bolting Degradation or Failure in Nuclear Power Plants 34 101 BWR Water level Redundancy 35 113 Dynamic Qualification Testing of large Bore Hydraulic Snubbers 36 115 Enhancement of the Reliability of Westinghouse Solid State Protection System l 37 121 Hydrogen Control for large, Dry PWR Containments l l 38 122.2 Initiating Feed-and-Bleed l 39 125.11.7 Reevaluate Provision to Automatically Isolate Feedwater from Steam Generator During a line Break 40 134 Rule on Degree and Experience Requirement 41 I.A.2.6(4) Training and Qualifications of Operating Personnel: Operator Workshops 42 I.A.2.7 Accreditation of Training Institutions

.o s ENCLOSURE 3 (CONT) COMPREllENSIVE LISTING OF 64 GSIs RESOLVED _UP TO 9/30/92 GSI NO. TITLE 43 1.A.3.4 Mcendng of Additional Operations Personnel 44 1.B.1.1(1) Organization and Management Long-Term Improvements: Prepare Draft Criteria 45 I.B.I.l(2) Organization and Management long-Term Improvements: Prepare Commission Paper 46 I.B.I.l(3) Organization and Management long-Term Improvements: Issue Requirements for the Upgrading of Management and Technical Resources 47 I.B.I.1(4) Organization and Management Long-Term Improvements: Review Responses to Determine Acceptability 48 I.C.9 Long-Term Program Plan for Upgrading of Procedures 49 I.D.4 Control Room Design Standard 50 II.A.1 Siting Policy Reformulation 51 II.E.2.2 Research on Small-Break LOCAs and Anomalous Transients 52 III.A.3.4 Nuclear Data Link 53 A-29 Nuclear Power Plant Desgin for the Reduction of Vulnerability to Industrial Sabotage 54 A-41 Long-Term Seismic Program 55 B-5 Ductility of Two-Way Slabs and Shells and Buckling Behavior of Steel Containments 56 B-26 Structural Integrity of Containment Penetrations

l ENCLOSURE 3 (CONT) i COMPREHENSIVE LISTING OF 64 GSIs RESOLVED UP TO 9/30/92 GSI NO. TITLE 57 B-54 Ice Condenser Containments 58 B-58 Passive Mechanical Failures i t 59 C-Il Assessment of Failure and Reliability of Pumps and Valves 60 12 BWR Jet Pump Integrity 61 61 SRV Line Break Inside the BWR Wetwell Airspace of Mark I and II Containments 62 82 Beyond Design Basis Accidents in Spent Fuel Pools 63 135 Steam Generator and Steam Line Overfill t 64 151 Reliability of Anticipated Transient Without SCRAM Recirculation Pump in BWRs l ~ b .mm. ,.m -..,_m.. .,..,m...im,. .,,m..m,,,,.._,,,.,m_m. _ _,, -,,.. ,,.,m. ...,,..,,,,3 y_,.. _,., ,,m,., ,,..,,.,.m....g .,.m ,,,_,_,,.,.}}