ML13336A044

Summary of 871009 Meeting W/Util in Bethesda,Md Re Licensee Identified Possible Failure in ESF Equipment.List of Attendees & Slides Used by Licensee Encl

ML13336A044
Person / Time
Site:	San Onofre
Issue date:	10/20/1987
From:	Knighton G Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
TAC-66405, NUDOCS 8710220169
Download: ML13336A044 (24)

Text

DCT 2 0 1987 Docket Nc.:

50-206 LICENSEE: Southern California Edison Company FACILITY:

San Onofre Nuclear Generating Station Unit 1 (SONGS-1)

SUMMARY

OF MEETING REGARDING LICENSEE IDENTIFIED POSSIBLE SINGLE FAILURES IN ENGINEERED SAFETY FEATURES (ESF) EQUIPMENT On July 30, 1986, SONGS-1 experience a transient event resulting from the failure of a pressure transducer (PT 459) in the Steam Flow/Feed Flow Mismatch Trip Circuitry. It was the staff assessment that the design of the steam/feedwater mismatch protection did not conform to the design capability with regard to single failure criterion as described in the Final Operating License Application. In a letter to the licensee on the subject dated September 23, 1986, the staff took the position that modification should made to bring the system into conformance with it's design basis. As a result of the identified deficiency, the staff also requested that the licensee perform a review of the Reactor Protection System (RPS) and the Engineered Safety Features Actuation System (ESFAS) for conformance to the single failure criterion and control/protection-interaction criterion. The results of the reviews were to be submitted to the staff for review.

In performing these reviews, licensee identified a number of previously unknown potential single failures associated with the ESF equipment for certain LOCA and main steam line break events. As required by NRC regulation 50.72, the licensee reported his finding by telephone on October 7, 1987. As a result of the discussions it was decided that an early meeting with the technical staff to describe the findings, their significance to safe operation, interim corrective actions to assure adequate safe operations and plans for final resolution. The meeting was scheduled for 8:30 AM October 9, 1987 at NRC Offices in Bethesda, Maryland.

The meeting was held as scheduled.. Enclosure 1 provides the list of attendees. provides the slides used by the licensee to brief the staff on the possible single failure identified, their significance to safe operation and interim corrective actions to assure adequate safe operation.

SUMMARY

Mr. Medford, the Licensing Manager for Southern California Edison Company (SCE), briefly described the Safety Injection System, Charging System and Main Feedwater System and their interaction under LOCA and Main Steam Line Break 8710220169 871020 PDR ADOCK 05000206 S

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-3 After a staff caucus, the licensee was advised, based upon their description of the problems found and the interim corrective actions that the staff concurs that public health and safety is maintained with continued plant operation while the staff reviews the reports to be submitted.

Original signez b:

Seorge W. Knigitn George W. Knighton, Director Project Directorate V Division of Reactor Projects -III, IV, V and Special Projects Office of Nuclear Reactor Regulation 10Ao/ 8 7

Mr. Kenneth P. Baskin San Onofre Nuclear Generating SouthErn California Edison Company Station, Unit No. 1 cc Charles R. Kocher, Assistant Mr. Joseph 0. Ward, Chief General Counsel Radiological Health Branch James Beoletto, Esquire State Department of Health Southern California Edison Company Services Post Office Box 800 714 P Street, Office Bldg. 8 Rosemead, California 91770 Sacramento, California 95814 David R. Pigott Mr. Hans Kaspar, Executive Director Orrick, Herrington & Sutcliffe Marine Review Committee, Inc.

600 Montgomery Street 531 Encinitas Boulevard, Suite 105 San Francisco, California 94111 Encinitas, California 92024 Mr. Stephen B. Allman Dennis M. Smith, Chief San Diego Gas & Electric Company Radiological Programs Division P. 0. Box 1831 Governor's Office of Emergency Svcs.

San Diego, California 92112 State of California 2800 Meadowview Road Sacramento, CA 95832 Resident Inspector/San Onofre NPS c/o U.S. NRC P. 0. Box 4329 San Clemente, California 92672 Mayor City of San Clemente San Clemente, California 92672 Chairman Board of Supervisors County of San Diego San Diego, California 92101 Director Energy Facilities Siting Division Energy Resources Conservation &

Development Commission 1516 - 9th Street Sacramento, California 95814 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane Walnut Creek, California 94596

ENCLOSURE 1 SONGS 1 ATTENDANCE OCTOBER 9, 1987 NAME ORGANIZATION TELEPHONE G. W. Knighton NRR/PDV 492-7331 R. Dudley NRR/DRSP 492-7685 Faust Rosa NRR/DEST/SELB 492-9466 Dom Tondi NRR/DEST/SELB 492-9490 S. Israel NRR/AEOD 492-4437 A. Thadoni NRR/DEST 492-7687 R. Jones NRR/SRXB 492-9461 Om Chopra SELB/DEST 492-9488 Rick Ornelas SCE/Licensing (818) 302-2672 Steve Root SCE Nuclear Engineering Jack Rainsberry SCE Nuclear Licensing (818) 302-1897 Mark Medford SCE/NESL (818) 302-1749 Gary Holahan NRR/DRSP 492-9411 Eileen McKenna OSP 492-7745 Walton Jensen NRR/OEAB 492/7380 Daniele Oudinot NRR/OEAB 492/8164 Tom Martin OEDO/REG OPS STAFF 492-8841

ENCLOSURE 2 SINGLE FAILURE ANALYSIS RESULTS SAN ONOFRE UNIT I OCTOBER 9, I987

AGENDA I.

BACKGROUND II.

SINGLE FAILURE PROBLEMS A.

480 VOLT SWITCHGEAR NO. 3 B.

MAIN FEEDWATER ISOLATION Ill.

SUMMARY

OF RESULTS

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BACKGROUND 0

PT 459 FAILURE JULY 30, 1986 o

REACTOR PROTECTION SYSTEM SINGLE FAILURE ANALYSIS o

ENGINEERED SAFETY FEATURES SINGLE FAILURE ANALYSIS

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SUMMARY

OF RESULTS RECIRCULATION Single Justification for Failure Event Results Continued Operation 4KV Bus IC LOCA Loss of Power to Align Recirc Using train I as lead CP and With or without LOP Loss of 2 CP's crediting operator action to SF prior to SI One train of SI available restore power, recirc is made Train 2 lead CP ovailab.le within 2Q minutes.

DC Bus #Il LOCA Loss of Power to Align Recirc Crediting operator action to LOP One Train of SI available restore power, recirc is made SF prior to SI available within 20 minutes.

Train I lead CP DC Bus #2 LOCA Loss of Power to 2 of 3 Crediting operator action to LOP Recirc discharge valves restore power, recirc is made SF after SI One Train of SI available available within 20 minutes.

'Before Recicr Train I Lead CP LOCA Loss of Power to 2 of 3 Using train I as lead CP and LOP Recirc discharge valves crediting operator action to SF ofter SI One Train of SI available restore power, recirc is made Before Recirc available within 20 minutes.

Train 2 Lead

SUMMARY

OF RESULTS FW ISOLATION Justification for Single Results Continued Operation Failure EventReut SEQ I or 2 MSLB FW flow to one or two Transient analysis criteria is met No LOP SG's continues up to 90 sec.

using better estimate analysis.

Inside containment LOCA FW flow to one or two SG's Steam generator overfill can be No LOP continues up to 90 sec.

terminated within acceptable limits by crediting operator action within 5 minutes.

DC Bus #1l MSLB FW flow to two or three SG's This event is not considered to be No LOP continues beyond 90 sec.

a significant contributor to risk.

Inside or Outside (P =06 )

Containment HV-852A or B MSLB inside containment Sl flow to three SG's for Transient Anslysis criteria is met With or without LOP 90 sec.

using better estimate analysis.

HV-852A or B MSLB outside containment Sl flow to three SG's beyond Transient Analysis criteria is mel With or without LOP 90 sec.

using better estimate analysis.

DISTRIBUTION Docket File NRC & L PDRs PD#5 Reading RDudley GKnighton OGC-Bethesda Eordan JPartlow ACRS (10)

TOMartin-EDO MRJohnson-EDO FRosa DTondi SIsrael AThadoni RJones GHolahan Wdensen DOudinot