05000361/LER-1982-023, Forwards LER 82-023/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-023/03L-0.Detailed Event Analysis Submitted

ML20055A587
Person / Time
Site:	San Onofre
Issue date:	07/09/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20055A588	List: 05000361/LER-1982-023, Forwards LER 82-023/03L-0.Detailed Event Analysis Submitted 05000361/LER-1982-023-03, /03L-0:on 820608,fire Suppression Water Spray & Sprinkler Sys Initiated by Manual Actuation of Deluge Valve. Cause Not Determined.Alternate Manual Actuators Being Considered
References
NUDOCS 8207190215
Download: ML20055A587 (2)

LER-1982-023, Forwards LER 82-023/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3611982023R00 - NRC Website

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S AN ONOFRE NUCLE AR GENER A TING S T A TION P.O. ISO R 128 S A N C LEMEN T E. C A LIFOR NI A 92672 di, H.s.nAv July 9, 1982 ST A tlOM M AN AGS A (7143497 7700 j

U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 92596-5368 Attention:

Mr. R. H. Engelken, Regional Administrator

Dear Sir:

1 Subject: Docket No. 50-361 l

Licensee Event Report No.82-023 San Onofre Nuclear Generating Station, Unit 2 This letter provides a written report, for information only, of an event involving inadvertent actuation of the Unit 2 automatic sprinkler system deluge valve in the Cable Tunnel on June 8, 1982. A completed Licensee Event Report (LER) is enclosed concerning this event.

I j

At approximately 0900, on June 8,1982, Control Room Operators noted a plant Fire Protection Computer alarm associated with deluge valve 2TSH8953, as well as indication of fire pump actuation. Simultaneously, I

a previously_ assigned Fire Watch Patrol was entering the Cable Tunnel on elevation 30 of the Cable Spreading Room and upon reaching the bottom of the ladder, observed water running over cable tray fire blankets apparently i

coming from the sprinkler nozzles at the 30 ft. elevation. The Control i

Room was notified and water flow halted by manually isolating the deluge l

valve after approximately 9 minutes of spray system flow.

- Collected water was removed and affected cable tray. fire blankets dried by forced hot air circulation. An investigation into the reason for the deluge valve actuation concluded that intentional manual actuation had occurred, for reasons and by persons unknown, at the pull station located at elevation 30 of the Turbine Building. Automatic actuation of the valve was ruled out since no early warning alarm had been received and inspection of the area revealed no indication of fire or excessive heat.

4 8207190215 B20709 PDR ADOCK 05000361 S

- PDR [fk

Mr. R. H. Engelken July 9, 1982 S^ction Emergency Preparedness and Engineering organizations are presently evaluating the manual actuation of all Fire Suppression Water Systems in an attempt to define design changes to reduce such occurrences. Consideration is being given to manual actuating devices requiring two separate intentional actions to open deluge valves manually.

Though no safety related equipment or systems were affected by this event, such systems could have been affected had the associated deluge valve for areas containino such systems been manually activated.

If there are any questions regarding the above, please contact me.

Sincerely,

Enclosure:

LER No.82-023 cc:

Mr. A. E. Chaffee (USNRC Resident inspector, San Onofre Unit 2)

U. S. Nuclear Regulatory Commission Office of inspection and Enforcement U. S. Nuclear Regulatory Commission Office of Management Information & Program Control Institute of Nuclear Power Operations J