05000206/LER-1981-017, Forwards LER 81-017/03L-0.Detailed Event Analysis Submitted

Forwards LER 81-017/03L-0.Detailed Event Analysis Submitted

ML20010C983
Person / Time
Site:	San Onofre
Issue date:	08/12/1981
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20010C984	List: 05000206/LER-1981-017, Forwards LER 81-017/03L-0.Detailed Event Analysis Submitted 05000206/LER-1981-017-03, /03L-0:on 810714,lube Oil Spraying from Cracked Instrument Line Ignited by Hot Exhaust Piping Above Diesel Engine.Caused by Instrument Line Cracking Due to Postulated Fatigue Failure Due to Vibrating Pressure Gauge
References
NUDOCS 8108210333
Download: ML20010C983 (2)

LER-1981-017, Forwards LER 81-017/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
2061981017R00 - NRC Website

text

,

i RWA 0 (E

Southem Califomia Edison Company $ i, SU 13.J l IF 0 S AN ONQFR C NUC LE AR GENE R A llNG S T ATION P.O. B O A 128 S AN C LEME N T E. C A LIF ORNI A 92672 August 12, 1981 U. S. Nuclear Regulatory Comission Office of Ir.spection and Enfor'.ement

( l r(Oh R:;gion V e,>

/y 1990 North California Boulevard Suite 202, Walnut Creek Plaza h

/(

Walnut Creek, California 94596

/1 9

w

/o a

_t e, j o-i Attention: Mr. R. H. Engelken, Director

\\ 6/,

/d/

DOCKET No. 50-206 b: ' i @ '

SAN ONOFRE - UNIT 1

Dear Sir:

This letter describes a reportable occurrence involving a fire in the No.1 (South) diesel generator building. Sul aittal 1s in accordance with the reporting requirements of Section 6.9.2.b. of Appendix A to Provisional Operating License DPR-13.

On July 14,1981 at 6:12 p.m., during diesel generator operability testing, the No.1 Emergency Diesel Generator caught fire when lube oil spraying from a cracked instrument line came in contact with hot exhaust piping and ignited. The building sprinkler system was out of service at the time, due to modifications being conducted on a fire main header. However, in accordance with the Technical Specifications, a continuous fire watch was being maintained utilizing a _ security guard who was assigned the sole responsibility of patrolling the Diesel Generator building.

The fire was imAdiately detected and extinguished within eight minutes by the station fire brigade using fira water hores. Operability of two off-site transmission lines and the remaining diesel generator was demonstrated as required by Technical Specification 3.7.2.B.

The instrument line failed during investigation of an oil leak. The leak, and subsequent <line failure during investigation is believed to have resulted from metal fatigue caused by vibration. A metallurgical examination of the failure location is being conducted. The instrument line was not documented on system drawings. As a result, an investigation is in progress to determine the source of the unauthorized installation.

The results of this review are expected to be available by September 15, 1981. A follow-up report $8N documenting our findings will Le forwarded to you at that time.

g 8108210333 810812 PDR ADOCK 05000206 S

PDR i

v

~.

U. S. Nuclear Regulatory Commission Page # 2 During the process of repairing the fire damage on the No. 1 Diesei Generator, any discrepancies from design drawings will be documented and dispositioned in accordance with the San Onofre Unit 1 Quality Assurance Manual. This includes an engineering review of nonconformances to assure proper disposition and documentation. Additionally, the No. 2 Diesel Generator Piping and Instrumentation Diagrams (P&ID's) were reviewed through the mechanism of walking down the various systems associated with this diesel.

The walkdown revealed several discrepancies between the P&ID's and the as-built configuration. However, our preliminary review indicates that none of the deviations are unauthorized, do not compromise the operability of the systems, and in fact, appear to be errors in the drawings. These items will be investigated further to confirm this conclusion.

1 The fire was confined to the governor end of the diesel generator.

Initial inspection revealed that fire damage to structural and mechanical components was minimal. Heat damage ta instrumentation, control and electrical equipment appears to be confined to areas in the vicinity of the fire. Smoke damage to sensitive electrical equipment was found in areas further from the fire.

The fire damage throughout the diesel building will be systematically evaluated to ensure that all affected equipment is included in a testing and inspection program. Damaged equipment will be repaired or replaced as 2

necessary. Pre-operational tests on the diesel generator and systems that may have sustained damage will be performed prior to returning the diesel generator to an operable status.

There was no degradation of plant safety during this incident as redundant systems were available and were tested at the frequencies delineated j

in the Technical Specifications.

If you should reauire additional information concerning this i

occurrence, please contact me.

Sincerely, O

/

1 l

H. B. R l

Stati anager i

Attachments:

Licensee Event Report 81-017' SS:dh:91U cc:

U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Office of Management Information & Program Control Nuclear Safety Analysis Center L. F. Miller - USNRC Resident Inspector i