ML20006D097

Provides Update to 880721 Ltr Re Performance of Seismic Margin Evaluation.Util Awaiting Issuance of Individual Plant Exams of External Events Generic Ltr Prior to Proceeding W/ Seismic Margins Study

ML20006D097
Person / Time
Site:	Perry
Issue date:	02/02/1990
From:	Kaplan A CLEVELAND ELECTRIC ILLUMINATING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
PY-CEI-NRR-1126, NUDOCS 9002120087
Download: ML20006D097 (2)

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% THEiCLEVELAND! ELECTRIC ILLUMINATING COMPANY y .P.O. Box 97 ' E : . PERR% OHIO 44081 5 TELEPHONE (216) 269 3737 l ADDREs8-10 CENTER ROAD ^

FROM CLEVELAND: 479 1200 3 TELEX:241099 ANSWER 8ACK: CEIPRYO

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. . .'Al Kaplan Serving The Best location in the Nation PERRY NUCLEAR POWER PLANT

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. February 2, 1990 f PY-CEI/NRR-1126 L '

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i I U.S. Nuclear Regulatory Commission-Document Control ~ Desk Washington, D..C., 20555 ,

Perry Nuclear Power Plant Docket No. 50-440 i Follow Up to Letter on Seismic Margins Evaluation LGentlement' .

1 This letter provides an update'related to the performance of a seismic margin evaluation for:the Perry Nuclear Power Plant (PNPP). The Cleveland Electric l Illuminating Companyj(CEI) has been following the developments in technical

.^ bases-for. conducting seismic margin evaluations.at nuclear facilities since t

1982 when the ACRS'first raised the issue for Perry, and again at the March-

. '13, 1986LACRS.'311th meeting which reviewed >the January.31, 1986 earthquake

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InlourJuly .21,.1988 letter to the staff (PY-CEI/NRR-0876 L) we indicated our~ .

' intent'.to carry out a seismic margins study when clear and final guidance was -

i 'e .available,'and.with the understanding that the study could resolve multiple t ' seismic issues. including seismic severe accidents. Based on the knowledge '

x .available at: that. time we anticipated a schedule consisting of completion of i the preparatory work, walkdowns and specific system / component / structure evaluations by=end ofLthe second refueling outage, and implementation of any .

required modifications by end of the third refueling outage. This schedule [

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.was. based on final NRC guidan'ce becoming available in 1989. j i ~In the interim time frame we have followed closely the NRC staff's development

=of guidance in this area and have continued participation in the Seismic

'0wners Group.(SOG) activities and the Seismic Issues Working Group (SIWG) of

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NUMARC. Additionally we reviewed and commented (through NUMARC) on the draft Generic' Letter on Individual Plant Examinations of External Events (IPEEE) which. addresses seismic margins as a resolution mechanism for the seismic portion'of;IPEEE.

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y. y gr Document Control Desk February 2, 1990 PY-CEI/NRR-1126 L As a. result of these activities, we have concluded that sufficient guidance is not available to proceed with'this activity on the schedule proposed in our r

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July 21,.1988 letter. Instead, CEI believes it prudent to await issuance of  ;

the-IPEEE Generic Letter (which we understand will contain the final guidance E on seismic margin methodology) before further developing our program. As noted in NRR letter dated March 30, 1989 (TAC No. 72197), there is a need to inject-industry and regulatory guidance into the seismic margin study. We >

have informed our consultants of our intent to put this project on hold until final guidance is available.

Additionally, there are several benefits to scheduling analysis of externally

. initiated severe accidents after preliminary development of the internal IPE which will commence in early 1990. Those benefits are (1) definition of potential " success paths" within the normal IPE development, (2) development of CEI personnel in severe accident analysis concepts and techniques which can be applied to IPEEE and (3) balancing of resources-to avoid overlapping proj e cts.

Therefore it is our intent to conduct our seismic margin study within the context of. resolving severe accidents under the IPEEE program following issuance of the related Generic Letter. We will evaluate our options within this program as it evolves and may elect to identify seismic margins at PNPP ,

by either seismic probabilistic risk ' assessment (SPRA) techniques'or the .

EPRI/NRC " seismic' margins" approach. Our approach will depend upon our. ,

understanding of the technical issues at that time. This represents the normal progression of conducting IPE and IPEEE studies in a logical and prudent path.

Please contact us by March 5, 1990 should this schedule change not be acceptable to the staff or the ACRS.

Should you have any questions, please feel free to call.  ;

Very truly yours, Al Kaplan Vice President Nuclear Croup ,

AK:njc Attachment cc: T. Colburn P. Hiland U.S. NRC Region III A. B. Davis T. E. Murley J. E. Richardson L. Reiter ACRS Subcommittee on Extreme External Phenomena