ML20128G455

Forwards Summary Rept of Results of GL 87-02, Verification of Seismic Adequacy of Mechanical & Electrical Equipment in Operating Reactors,Unresolved Safety Issue (USI) A-46

ML20128G455
Person / Time
Site:	Pilgrim
Issue date:	09/30/1996
From:	Boulette E BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20128G462	List: ML20128G455 ML20128G536 ML20128G562 ML20128G587
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR BECO-LTR#96-085, BECO-LTR#96-85, GL-87-02, GL-87-2, NUDOCS 9610090039
Download: ML20128G455 (3)

Text

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Boston Edison Pdgnm Nuclear Power Station s Rocky Hdi Road Plymouth, Massachusetts 02360 E. T. Boulette, PhD senior Vice President-Nuclear September 30, 1996 BECo Ltr. #96085 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Docket No. 50-293 License No. DPR-35 Summary Report 1

Generic Letter 87-02. Verification of Seismic Adeauacy of Mechanical and Electrical Eauipment in i Operatina Reactors. Unresolved Safety Issue (USI) A-46 This letter provides a summary report of the results of our USl A-46 review. As a member of the Seismic Qualification Utility Group (SOUG), we adopted the methodologies of the NRC approved Generic implementation Precedure (GIP) Revision 2 for conducting the USl A-46 reviews, documenting our findings, and reporting the results. The summary report is comprised of three enclosures as follows:

i Er. closure A," Safe Shutdown Equipment List Report for the Resolution of USl A-46,"(SSEL) provides the information recommended in GIP Section 9.2 for describing the assumptions, I methods, and results of the effort to identify equipment needed to accomplish the safe shutdown i functions of reactor reactivity control, reactor coolant pressure control, reactor coolant inventory control, and decay heat removal. It also describes the method used by the Operations Department for verifying the compatibility of the SSEL with the plant operating procedures.

Enclosure B, " Seismic Evaluation Report for the Resolution of USl A-46," provides the information recommended in GIP Section 9.4 for describing the methodology and results of the seismic revie6 of active mechanical and electrical equipment, selected tanks and heat exchangers, and cable and conduit raceways.

Enclosure C, " Relay Evaluation Report for the Resolution of USl A-46," provides the information recommended in GIP Section 9.3 for describing the results of the review of essential relays identified in the circuits of mechanical and electrical equipment needed for safe shutdown of the plant.

-l 9610090039 960930 PDR ADOCK 05000293 P PDR

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• Outliers, presently resolved and those to be resolved, are anessed utilizing the methodologies as described in these reports. We are pursuing resolution of the remaining outliers and will continue closure for on-line issues during the remainder of the current operating cycle as well as the next operating cycle. We expect to resolve the remaining outliers no later than RFO #12, currently scheduled to commence April 1999.

Also, during our identification of safe shutdown equipment, we determined the non-safety related equipment and piping in the nitrogen gas supply used to operate the NSSS safety relief valves for reactor pressure control are not sufficiently rugged to meet seismic requirements. GIP Section ,

2.2.3 calls for achieving and maintaining hot shutdown during the first seventy-two hours following l a safe shutdown earthquake. Each safety relief valve has a dedicated safety related nitrogen gas I accumulator that is sized for twenty valve actuations within the first eight hours after the normal supply is lost. Since each accumulator is sized to operate the associated safety relief valve for i only eight hours instead of seventy-two, the long term Residual Heat Removal (RHR) equipment is included on the SSEL. This equipment allows a reactor cooldown to be performed within eight hours and maintained indefinitely. However, long term RHR is performed by the Shutdown Cooling Mode of the RHR system which is not single failure proof. Therefore, modification of the plant to assure the capability to maintain the reactor vessel depressurized for at least seventy-two hovs without use of the RHR Shutdown Cooling Mode is planned and also will be completed no l later than RFO #12. Section 4.1.2 of the SSEL report discussos this situation in greater detail.

l Should you have any questions, please contact Mr. J. D. Keyes, Regulatory Affairs Department, ,

at (508) 830-7942. l

[E. T. Boulette, PhDLLWg I Commonwealth of Massachusetts)

County of Plymouth )

Then personally appeared before me, E. T. Boulette, who being duly sworn, did state that he is Senior Vice President - Nuclear of Boston Edison Company and that he is duly authorized to '

execute and file the submittal contained herein in the name and on behalf of Boston Edison Company and that the statements in said submittal are true to the best of his knowledge and belief.

My commission expires: 36 & MW V DATE ' (NOTARY PUBLIC 4 ~

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cc: Mr. Alan B. Wang, Project Manager

! Project Directorate I-1

Office of Nuclear Reactor Regulation Mail Stop

14B2 U. S. Nuclear Regulatory Commission i 1 White Flint North

11555 Rockville Pike l Rockville, MD 20852 1

! Regional Administrator, Region I i U.S. Nuclear Regulatory Commission

! 475 Allendale Road j King of Prussia, PA 19406 l Senior Resident inspector ,

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