ML13319A793
| ML13319A793 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/06/1987 |
| From: | Medford M Southern California Edison Co |
| To: | NRC Office of Administration & Resources Management (ARM) |
| Shared Package | |
| ML13319A794 | List: |
| References | |
| NUDOCS 8711100271 | |
| Download: ML13319A793 (4) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M. 0. MEDFORD TELEPHONE MANAGER OF NUCLEAR ENGINEERING (818) 302-1749 AND LICENSING November 6, 1987 U. S. Nuclear Regulatory Commission Attention:
Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 ESF Single Failure Analysis San Onofre Nuclear Generating Station Unit 1 By letter dated October 16, 1987, the NRC was provided with a report describing the significant findings of the then ongoing single failure analysis of the Engineered Safety Features (ESF) for San Onofre Unit 1. The analysis was performed as requested by NRC letter dated September 23, 1986 and resulted from the failure of PT-459 on July 30, 1986. The final report documenting the ESF single failure analysis was committed to be provided by November 6, 1987. The purpose of this letter is to submit the final report for NRC review.
Accordingly, the report entitled, "Engineered Safety Features Single Failure Analysis, San Onofre Nuclear Generating Station, Unit 1," dated November 1987, is enclosed. This report describes the methodology used to perform the single failure analysis and documents the results obtained.
The design of the auxiliary feedwater system used in the analysis is the design which will be implemented at the next refueling outage. It incorporates the addition of a third auxiliary feedwater pump and eliminates the existing single failure susceptibilities of the system. Also, credit was taken for the steam/feedwater flow mismatch trip modifications which will be implemented at the same time.
The design descriptions for the modifications to the auxiliary feedwater system and the steam/feedwater flow mismatch trip will be provided to the NRC by November 20, 1987. Design descriptions for additional modifications, to resolve other single failure concerns identified by this effort, will be 8711100271 871106 PDR ADOCK 05000206 S
Document Control Desk November 6, 1987 provided with the November 20, 1987 submittal to the extent that they.are available. If necessary, a schedule for submittal of additional information will be provided at that time.
If you have any questions or desire additional information regarding this subject, please contact me.
Very truly yours, Enclosure cc:
- 3. 0. Bradfute, NRR Project Manager, San Onofre Unit 1 J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3
ENGINEERED SAFETY FEATURES SINGLE FAILURE ANALYSIS SAN ONOFRE NUCLEAR GENERATING STATION UNIT 1 NOVEMBER 1987
REGULA#Y INFORMATION DISTRIBUTIq SYSTEM (RIDS)
ACCESSION NBR:8711100271 DOC.DATE: 87/11/06 NOTARIZED: NO DOCKET #
FACIL:50-206 San Onofre Nuclear Station, Unit 1, Southern Californ 05000206 AUTH.NAME AUTHOR AFFILIATION MEDFORD,M.O.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Forwards "ESF Single Failure AnalysisSan Onofre Nuclear Generating StationUnit 1,"
final reptoper 871016 ltr.
Analysis performed per NRC 860923 ltr re failure of PT-459 on 860730.
DISTRIBUTION CODE: AOO1D COPIES RECEIVED:LTR ENCL SIZE: 0 TITLE: OR Submittal: General Distribution NOTES:License Exp date in accordance with 10CFR21 2.109.
05000206 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1
0 PD5 PD BRADFUTEJ
- L %L INTERNAL: ARM/DAF/LFMB 1
NRR/DEST/ADS 1
NRR/DEST/CEB 1
NRR/DEST/MTB 1
NRR/DEST/RSB 1
NRR/DOEA/TSB NRR-/PM4A-SILRB 1
OGC/HDS2I JRB 01 1
1 RES/DE/EIB 1
EXTERNAL: EG&G BRUSKE,S 1
LPDR 1
NRC PDR 1
1.'
NSIC 1i 1 COIE TOTAL NUMBER OF COPIES REQUIRED: LTTR 21 EN