ML20237L292

Recommends That Commission Approve Staff Plan to Extend Benefits of Isap Approach to All Licensees as Element of Implementation Program for Severe Accident Policy Statement

ML20237L292
Person / Time
Issue date:	08/31/1987
From:	Stello V NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO)
To:
References
TASK-PINV, TASK-SE SECY-87-219, NUDOCS 8709080332
Download: ML20237L292 (11)

Text

-

N>

l ^

! e 1

. ., l

\...../

POLICY ISSUE i August 31, 1987 SECY-87-219 gg For: The Commissioners ,

From: Victor Stello, Jr. I Executive Director for Operations

$ubject:

INTEGRATED SAFETY ASSESSMENT'P.R0 GRAM

Purpose:

To inform the Commissioners of the experience gained in I the Integrated Safety Assessment Program (ISAP) pilot' l program and to recommend continued use of the ISAP l

methodology as part of other NRC' programs.

1

Background:

SECY 84-133 describes the concept and implementation of i the Integrated Safety Assessment Program (ISAP) in detail. i To summarize, the objective of ISAP was to provide a I comprehensive review for operating reactors which would address all safety issues and provide an integrated, cost-effective implementation plan using both deterministic and probabilistic techniques. ISAP was also to provide the technical bases to resolve all outstanding licensing actions, I

establish overall plant improvement' schedules and serve as  ;

a benchmark from which future regulatory actions could' be  !

judged, on a plant-specific basis.

)

l The ISAP pilot program was_ initiated in November 1984 with I

the issuance of the Commission'.s Policy Statement on the ,

i Systematic Safety Evaluation of Operating Nuclear Power l l- Reactors (49 FR 45112). The major' elements of ISAP, as presented in the policy statement, are: ~(1) a review of the lessons learned from the Systematic Evaluation Program (SEP), pending regulatory requirements, licensing actions

' and licensee plant improvement initia'ives; (2) performance of a plant-specific probabilistic safety assessment (PSA);

(3) a compilation and analysis of plant operating experience data; (4) the' analysis in an integrated assessment of the topics resulting from (1), (2) and (3); and (5) the issuance of an integrated implementation schedule.

CONTACT:

M. Boyle, ISAPD x27636 g7ogo332 M

i As a result of changes in the FY 1986 budget appropriations, the staff did not start the implementation of ISAP until l

May 1985 when the pilot program was revised (SECY 85-160). '

The revised pilot program provided for the review of two plants that had participated in SEP and limited the review of the PSA to immediate ISAP considerations. Northeast Nuclear Energy Company and Connecticut Yankee Atomic Power Company (the licensees) volunteered Millstone Unit 1 and Haddam Neck, respectively, to participate in the pilot program. Since both plants had already participated in SEP, the technical review of the SEP lessons learned had been completed when the pilot program began. .The milestones associated with the ISAP actions completed thus far and those necessary to complete the pilot program are presented in Enclosure 1. ,

Discussion: From an examination of the ISAP pilot program milestones listed in Enclosure 1, it can be seen that the technical review work, the PSA and operating experience reviews have j been completed for both plants. The draft Integrated Safety Assessment Report (ISAR) for Millstone Unit 1 (NUREG-1184) was issued for comment on April 14, 1987 with the final report and integrated implementation schedule to be issued in September 1987. The draft report for Haddam Neck was issued on August 18, 1987 and the final report is scheduled to be issued in October 1987. The draft ISARs for both l

plants are provided to the licensees, an independent peer review group, and the ACRS for comment. The license ~es are to use the draft reports as the bases for developing the integrated schedules and as part of the bases for the possible elimination of low importance actions from the schedules. The final ISARs will address the comments as appropriate and will incorporate the integrated schedules.

The integrated schedules or the methodology for developing

)

an integrated schedule are expected be made part of the operating licenses.

One of the tenets of the ISAP program was the deferral of-issues until they could be evaluated in an integrated assessment. However, if, during the ISAP review, the staff or licensee explicitly determines that, to protect the public health and safety, prompt action is required to be

' taken on an ISAP issue, then the deferral will be lifted and the action must be taken.

In this regard, two of the major findings in ISAP were iden-tified upon the completion of the PSAs by the licensees.

For Millstone Unit 1, the licensee oported that 60% of the total calculated core melt frequency was due to a failure to maintain adequate long-term decay heat removal capability.

The licensee identified and implemented the immediate cor-rective actions it could take to reduce this contribution to

.8 :v 1 .. . ,,

'. .c 5 '

. /

/ e s

' risk.- The licensee.also' initiated -an evaluItion! Program to '

determine'what other actions could be taken;in the longer j term. -The ISAP review'identifidd this evaluation' program-- 1 to be a high priority activity.= For Haddam Neck, the! '

H

. licensee reported.that the lossLof motor control center..

MCC-5'in'the switchgear room.would cause;a loss of;..

function of critical equipment 'and prevent-safe' shutdown . <

of the~ plant.:.This'shows<up asa major transientLinitiator 'l and dominant contributor to. the core melt:frequencylinsthei .;

PSA. ~The licensee took'immediate corrective actionsitoi >

reduce this~ source of_ risk..

1 The performance of a PSA by the licensees' not Lonly identik fied areas of significant risk ~ where immediate corrective c :l actions were necessary,- but the PSA also' identified ' areas,_ .

such as plant-specific design changesJ resulting from' . .

1

igeneric NRC requirements .or-licensee initiatives.. that, while developed to increase plantisafety or availability, actually increased risk.L For Millstone Unit 1.-thel licensee reported, after performing a probabilisticievaluation, that

! the system the licensee designedL using deterministic' methods, to _ meet NRC generic requirements. for degraded grid: voltage protection for Class 1E power systems'would increase the>

~ likelihood of station-blackout:by 240L * 'The degraded grid.

protection system has been. redesigned byLthe licensee taking-into account the PSA findings and implementation is planned for the next: refueling. outage. For~ Haddam _ Neck, the licenseefwas planning to add a new system to: supply;the

~

nitrogen blanket for the demineralized water storage tank l due to availability' problems ,in'the~old system..>However, the PSA indicated that'the new system would be proneito a ,

single failure that might. lead toEloss.of.this storage tank..

In this case, the licensee is modifying;the current system '

l rather than adding a new system. .

~

.The staff's review of the PSA and the' operating experience'-

analysis identified several< areas, although.not requiring j imediate' actions, that could be significant contributors -  !

to risk. .These areas-.were included .in the integrated:

, analysis for each plant and will te implemented accordingm c to the priority determined in the integratediassessment. -

]

1 I

• The licensee reported that the Mil.1 stone Unit ~ 1 electHeal bus arrangement,' due to its lack of symmetry, is~ not readilyLeompatible .  !

with a modification which requires an auto-reinstatement of load-shed-feature. The ' staff has investigated the-generic implications of _ the licensee's^ degraded grid protection: findings a'nd,' based'on the unique

-design of the Millstone 1 electrical. bus arrangement, has concluded d that the identified problem is plant-specific. 1 1

e a 4 i >

s,

+

-]

~

Perfonnance of the PSAs by the licensees, and review of the PSAs and operating experience analyses by the staff have led to better understanding of the plant's operating char-acteristics and capabilities by both the licensees.and the staff. It should be noted that the performance of an operating experience review by the staff not only identified new areas to be evaluated in the integrated' analysis and a better understanding of the plant, but also ~ served to verify the findings in the PSA.

The ISAP integrated assessment performed by the licensee has the potential to identify what were originally separate review a singleareas, find common integrated action toelements between resolve the them separate and propose'.

concerns, For Millstone Unit 1, it was found that a single modification..

could resolve separate staff concerns in the areas'of tornado missile protection, station blackout and fire protection.

The integrated assessment also provided an opportunity for the staff and licensee to address pending requirements on a plant-specific basis. For example, the staff and licensees discussed potential requirements for topics such as. severe accidents, station blackout and Mark-I containments in -light of existing plant design and the plant-specific PSA to provide a greater understanding of plant operating characteristics and to make additional recommendations for plant modifications to effect an immediate reduction in risk in advance of resolution of these topics and formal issuance of the.

requirements.

The result of the integrated assessment 'is the list of actions to be implemented by the licensees.. The development by the licensees of an action prioritization methodology, using the PSA and operating experience.as prioritization tools, allows the licensees for the first time in a fonnal documented manner. to evaluate the priority of all proposeo actions in light of the significance of all other existing actions. The resulting integrated implementation. schedules will provide a stable and predictable basis for both the licensees and staff to manage current workloads to estimate resources for future projects.

In sumary, the benefits 'of performing a PSA and operating-  :

experience review are-demonstrated by the. identification of-areas of significant risk requiring immediate action, the identification of areas designed to increase safety but which actually increase risk and the identification of areas for consideration in the integrated assessment. The ISAP integrated assessment demonstrated the benefits of proposing a single resolution'to severai issues. The ISAP prioritization of actions . benefits the licensee and the NRC by providing a rational schedule for implementation of actions' l and provides a basis for the possible elimination of actions that were determined to have low safety significance.

i

n s - - --

1 c- -; 7

~

., q w w .

~

1 1 -

The . staff believes that;the experience:with the ISAP. pilat 1 program has demonstrated the potential benefits to licensees, l the public and the NRC of-integrated assessments utilizing plant-specific PSAs and operating experience reufews. tThe.

staff has concluded that the most cost-effectivf.way to- )p extend those benefits to additional l plants wou',d be to combine the features of the ISAP approach with the imple 1 1 mentation of the. Comission's. severe accident. policy. [ i In'theSevereAccident'PolicyStatement(50FR.32138)2the-Comission mandated that each licensee perform 'a systematic plant ~ examination to-search for vulnerabilities to' severe  ;

-accidents. The concept of systematic plant examinations; J has featureslin comon with11 SAP. , That is,2 both programs i

.are :trying 'to: identify plant . vulnerabilities and develop .

plant-specific methods of resolving the vulnerabilities..

~

The severe accident systematic plant examinations will be used -to identify vulnerabilities that. are beyond the'- .

defined. design' basis events and the~ single; failure criteria-which are the principal bases'of the ISAP evaluation.'lIn:

the ISAP approach, all -issues.are analyzed at one time.

An operating. experience analysis is performed,which serves to identify plant vulnerabilities, to validate the PSA'and j together with the PSA serves.as a tool-in the development of implementation schedules.. If the ISAP approach is combined with the implementation of the severe. accident:

policy, then once' theisystematic' plant? examination has.been completed for a plant, tho' identified vulnerabilities ~and . q current licensing actions would be prioritized for the j development of a cost-effective, risk-based implementation -

plan. ~ This combination of programs' would require that the' il systematic plant examination provide information.not only on severe accidents, but also on design basis events'as ]

y required in ISAP.' j a

The Comission presently has beforelit SECY-87-172,

" Integrated Schedules Policy Statement.". The program addressed by that policy statement provides licensees i the opportunity to develop integrated schedules based  :{

upon a prioritization process developed by;the licensee '

-and approved by the staff. It' is not presently a re-quirement of this program that a PSA belperfomed and a used in the prioritization process. Experience with the ISAP. pilot program has shown.the benefits of using) L i

a plant-specific PSA in prioritizing implementation j schedules, including the-opportunity to ju'stify ,

j!

elimination of items from the. schedule because of their low impact on safety improvement.~ Continuation lof the-ISAP program in combination with the! severe accident program, as discussed above,'would providellicensees 1 with valuable insights that could'be used.in the-  !

development of integrated schedules for NRC= requirements -

as well as. licensee initiatives. ,

j a

-l

_ _ _.m .E_.__________i__ _ih d

, s

\

The staff believes that it is in the best iinterest of.the public, the' industry and the NRC'to extend;the benefits of-

'the ISAP approach by continuing ISAP.not as a separate.

. program, but rather as an important element-of,the . -

implementation program for the severe accident policy.

The objective of this new program would be to perform a comprehensive review of. plants for vulnerabilities' to severe accidents and to address. current safety issues to provide an integrated. cost-effective implementation plan..

The program _would also serve as a benchmark from which a future proposed regulatory actions could ie' judged ~on a.

plant-specific basis. The results of the program could 4 j

also be used by licensees to-develop integrated schedules.-

The staff met with the Advisory Comittee on Reactor' Safeguards (ACRS) on July 7 and 9,1987, to' discuss the j

results of the Millstone Unit 1.ISAP review and to. discuss potential approaches for.the continuation' of ISAP ' The .

ACRS met with the Comission on August 6,1987,. to discuss, among other things, the ACRS's evaluation of the ISAP pilot program. The staff's proposal.in this paper is consistent with the ACRS's conclusions.

Recomendaticn: That the Comission approve the staff plan to extend the j benefits of the ISAP approach to all licensees as an. '

i element of the implementation program for the Severe-Accident Policy Statement; that.is, tc combire the . l features of the ISAP pilot program and the systematic plant examination provision of the. Severe Accident Policy i

Statement.-

&[

/- -

ictor. Stello, Jr. i Executive / Director l

'for Operations -

j s

Enclosure:

ISAP Pilot Program Milestones {

3

~

')

i 1

3

.(q ,)

i___'__i._____.=___..=-

__ _ - - - _ =

=. ,

Commissioners' to-SECY by c.o.b.comments Septemberor16, consent 1987.should be provided directly-Commission staff office comments, if.any, should be'. submitted to thetoCommissioners copy SECY. NLT September-7, 1987,.-with an1information additional time for analytical review and comment, theIf the paper i Commissioners and the Secretariat should be apprised of when comments may be expected.

l

' DISTRIBUTION:

l Commissioners l

i OGD (H ST)

OI '

OIA GPA OCA SP OPA REGIONS 4 EDO j DEP EDO DEP EXEC DIR FOR' REGIONAL OPS ARM I CENTRAL FILES AEOD NMSS NRR .

RES OFF OF ENFORCEMENT OGC (MNBB) '

OSP DMB ACRS ASLBP '

-ASLAP SECY

\

Enclosure 1 ISAP PILOT PROGRAM MILESTONES i i

March 23, 1984 )

SECY 84-133 described a four plant ISAP pilot program in lieu j of SEP Phase III and the National Reliability Evaluation -

s Program.

l November 15, 1984 ISAP policy statement was published in the Federal Register (49 FR 45112). i May 6, 1985 SECY 85-160 described a revised ISAP pilot program for two plants: Millstone Unit 1 and Haddam Neck.

May 17, 1985 Northeast Utilities (NU) submitted a proposed set of " topics"  !

for both plants; the proposed scope was a revision and I update to two previous proposals (June and December 1983).

June 1985 Meetings held with NU to discuss scope of topics, pending licensing actions, generic issues, and plant improvements.

July 10, 1985 Millstone 1 Probabilistic Safety Analysis (PSA) submitted; 4

immediate corrective action (long-term cooling) and topic-related issues were defined in the forwarding letter.

July 31, 1985 Staff evaluation identified 80 topics for Millstone 1 and 70 topics for Haddam Neck, as well as projects that were to be completed independent of ISAP. Documentation requirements were defined for deterministic, probabilistic and plant improvement summaries.

August 13, 1985 to NU submitted individual topic safety analyses for Millstone 1 i i February 4, 1986 together with applicable topic probabilistic summaries. j August 19, 1985 NRC issues draft Millstone 1 operating experience report for comment. fi September 23, 1985 Draft SAIC PSA evaluation report for Millstone 1 issued to NU for factual corrections and comments. j October 3, 1985 NU submitted comments on ISAP operating experience review analysis, l j!

October 21, 1985 NU submitted comments on draft SAIC Millstone l'PSA evaluation 3 report.

I November 20, 1985 Commission Memorandum and Order issued granting a schedular extension to 10 CFR 50.49 for the environmental qualification of eleven valve operators to be resolved under ISAP for  !

Millstone 1 but not later than August 30, 1987. l i

e

n ,

e ', '

2- I January 3, 1986 Final SAIC PSA evaluation report issued to NU for use in the Millstone 1 integrated assessment.

February 14, 1986 NU submitted a proposed ISAP schedule for Haddam Neck. l l

February 19, 1986 Commission briefing.on ISAP status. l March 3, 1986 Safety evaluation for Millstone 1 issued which describes the results of the topic reviews: (1) specific issues to be.

addressed in the integrated assessment, (2) resolved topics, {

and (3) three new topics and the related issues resulting -

from the PSA and operating experience review.

March 26, 1986 NU submitted the supplemental fire analysis for the Millstone 1 PSA. 1 I

March 31, 1986 Haddam Neck PSA submitted by NU; immediate corrective actions l (small break LOCA) and topic related issues were defined 1 in the forwarding letter. l April 22, 1986 SECY 86-121 presented first annual ISAP. progress report. {

s June 13, 1986 to NU submitted individual topic safety analyses for Haddam Neck l November 18, 1986 together with applicable topic probabilistic summaries, j July 3, 1986 Draft Haddam Neck operating experience. report issued to NU for comment. j July 31, 1986 NU submitted their proposed resolution of the Millstone 1 integrated assessment issues together with a priority l ranking for each issue. q l

August 19, 1986 NU submitted comments on draft Haddam Neck operating i experience report. I September 30, 1986 Staff issued final Haddam Neck operating experience  !

report.

November 16, 1986 Draft SAIC PSA evaluation report for Haddam Neck issued j

to NU for factual corrections and comment. -

I December 12, 1986 NU submitted their proposed resolution of the Haddam Neck j integrated assessment issues together with a priority 3 ranking for each issue.  !

I January 14, 1987 NU submits comments on draft SAIC Haddam Neck PSA evaluation l report.

April 14, 1987 Staff issued draft Millstone 1 Integrated Safety Assessment  ;

Report (NUREG-1184) for comment. I May 27, 1987 Final SAIC PSA evaluation report issued to NU for use in the l Haddam Neck integrated assessment.

r ,, ,

, .q

/

. 1

-l May 26, 1987 Comments on M111 stone'1. draft ISAP received from peer -!

review group. Comments from NU due at 'end of month.

May 1987 Staff issues second ISAP progress report and recommendations .,

for future ISAP Actions. '

July 1987 Staff to present ISAP experience and recommendations to ACRS; ACRS to issue letter report.

I August 18, 1987 Staff issued draft Haddam Neck ISAR to NU and peer review '

group. ,

• September 1987 Staff to issue' final Millst'one 1 ISAR and start process'for Millstone 1 license amendment to incorporate integrated I schedule plan.

)

• September 1987 Comments on Haddam Neck draf t ISAR due.

• September 1987 Staff to present Haddam Neck ISAP and proposal for the continuation of ISAP to ACRS.

• 0ctober 1987 Staff to issue final Haddam Neck ISAR and; start process . i for Haddam Neck license amendment to incorporate integrated  !

schedule plan. '

• Current completion schedule. l 1

- - - _ - _ _ _ _ - _ . _ _ _ . _ _ _ _ - - - - . _ - _ _ _ - - - - - - . _ - _ _ _ _ _ _ - - - _ _ . -- _ _ - - . . _ . - _ . _ _ - _ -- _ _ _ - - . ----..--..-_J

,- "vvvvvvyyyy Document Control Desk, 016 Phillips TRANSMITTAL TO:

t i i ADVANCED COPY TO: The.Public Document Room 1 E

E DATE: //[d /f 7 SECY Correspondence & Records Branch i FROM:

." I I I t

t Attached are copies of a Commission meeting transcript and related meeting document (s). They are being forwarded for entry on the Daily Accession List and i placement in the Public Document Room. No other distribution is requested or- h R-t required.

Meeting

Title:

N M Md -l i Q% AL ' aend] i Meeting Date: //,/c,4// 7 Open N Closed i

- l Item Description *: Copies Advanced DCS

@ I I"

Copy,

' l to PDR_

3

$ ~

1

!f i

1. TRANSCRIPT 1

b*

gl 4)l4&Y

/ V

/ \

N9 1

\

2.& ~f .

3.

q G N

4.

2 il=

s. $

6.

i

• PDR is advanced one copy of each document, two of each SECY paper.

t C&R Branch files the original transcript, with attachments, without SECY g l  ;

i papers.

8 9

alm h hYlYbYlYbYl bI bbblflflhshbbhhkl

_