ML20247K016

Documents Closure of PRA Commitments in Rev 2,Section III.11.0 of Plant Nuclear Performance Plan & PRA Actions Required for Restart.Util Will Address plant-specific Accident Vulnerabilities Per Generic Ltr 88-20

ML20247K016
Person / Time
Site:	Browns Ferry
Issue date:	07/26/1989
From:	Michael Ray TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-88-20, TAC-63178, NUDOCS 8907310418
Download: ML20247K016 (2)

Text

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,W' 9 TENNESSEE VALLEY ' AUTHORITY CH ATTANOOGA, TENNESSEE 37401

, 5N 157B Lookout Place JUL 261889- .

, U.S. Nuclear, Regulatory Commission

' ATTN: Document Control Desk

-Washington, D.C. ?20555 Gentlemen:

In the Matter of ). Docket Nos. 50-259 Tennessee. Valley Authority ) 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - PROBABILISTIC RISK ASSESSMENT (TAC 63178)

This letter documents the closure of the probabilistic risk assessment (PRA) commitments contained in Revision 2 of the' Browns Ferry Nuclear Performance Plan (NPP) Section 111.11.0 and the PRA actions required for restart.

.As stated:in NRC's May 18, 1988 meeting summary, the staff's major concern for

' Unit 2 restart is.whether the BFN plant is an outlier in terms of core melt frequency compared to similar plants of similar vintage. To address this concern,,the NRC staff requested the submittal of:

=TVA's rationale for concluding that the revised PRA will reflect the configuration of Unit 2 at the time of restart, and a su'nmary document indicating the changes made between the January 1986 EdraftsPRA reviewed by the NRC staff in its October 1, 1987 letter and the Septeriher 1987 revision.

As committen in the NPP, TVA provided this information by letter from R. Gridley, osted August 25, 1988.

NRC's May 18, 1988 meeting summary also stated that upon completion of their scoping review cf the TVA submittal, the NRC staff would conduct an audit of the September 1967 revised draft PRA and the supporting documentation. NRC conducted this review on November 1-2, 1988 at TVA's offices in Knoxville, Tennessee. As a result of this audit, a concern was sent to TVA by letter from S. Black to 0. 3. Kingsley, Jr., dated March 29, 1989. TVA responded to this concern by letter from R. H. Shell to NRC, dated June 15, 1989.

'The NPP commitments to perform a full scope PRA and to provide the schedule

'for this update prior to restart were originally made by letter from S. A. White to NRC, dateo June 9, 1987. TVA considers these commitments to be

. closed as they have been saperceded by the issuance of Generic Letter 88 " Individual Plant Examinattan for Severe Accident Vulnerabilities -

10CF R50. 54(f.r. " The Generic Letter requests licensees to submit their

'8907310418 890726 PDR ADOCK 05000259 [D)Or p PDC >

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.h proposed program and schedule for completing the Individual Plant Evaluation 1 within 60 days of receipt of the final guidance documents. TVA is currently updating the September 1987 version of the draft BFN PRA as the basis for l responding to the Generic Letter.

In summary, TVA has responded to the NPP and restart commitment *; and is in the )

l process of updating'the NPP ,to reflect the closure of these cot,mitments. TVA {

i intends to address the issue of plant specific severe accident vulnerabilities I consistent with the requirements of Generic Letter 88-20. There are no (

l commitments 4 contained in this letter. TVA requests the issuance of a Safety I Evaluation documenting the resolution of this issue for restart.

.If you have any questions, please telephone Patrick Carier at (205) 729-3570.

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Very truly yours, TENNESSEE VALLEY AUTHORITY c ,9 Manage #,Nuclerl. Licensing and Regulatory Affairs cc: Ms. S. C. Black. Assistant Director for Projects TVA Projects Division.

U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Assistant Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nuclear Plant t Route 12, Box 637 Athens, Alabama 35609-2000 l

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