ML20083R142

Ro:On 720615,odor of Warm Electrical Insulation in Control Room Investigated & Traced to Relay 6K28.Relay Replaced

ML20083R142
Person / Time
Site:	Oyster Creek
Issue date:	06/26/1972
From:	Finfrock I JERSEY CENTRAL POWER & LIGHT CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20083R146	List: ML20083R142
References
NUDOCS 8303310459
Download: ML20083R142 (1)

Text

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M ADISoN /sVENUE AT PUNCH BOWL Ro AD e MoRRISTOWN N.J. 07960 e 539 6111 June 26, 1972 ,

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Mr. A. Giambusso d, ')

Deputy Director for Reactor Projects Directorate of Licensing

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United Ste.tes Atomic Energy Commission

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Washington, D. C. 20545 %5*? X- '

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Dear Mr. Giambusso:

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Subject:

Docket 50-219 Oyster Creek Station Relay Failure The purpose of this letter is to report to you, as a matter of interest, a relay failure which occurred at the Oyster Creek Station.

On June 15,1972 at 7:30 p.m. , an odor of warm electrical insulati'on in the Control Room was intestigated and traced to relay

, 6K28. The function of this relay is as follows:

a. Seal in a trip signal in the AC control circuit for main steam isolation valves NSO4A and NSO4B, and *

b. Trip recirculation loop sample valve V-24-30 upo'n an isolation signal The reactor was suberitical, depressurized and vented at the time of discovery of the failure with the mode switch in " REFUEL" and one shutdown cooling system pump in service maintaining reactor water temperature at approximately 1250F. The main steam isolation valves and the isolation condemer vent valves were shut prior to the failure /

and remained shut. The power supply fuse, 6F6, was removed causing the relay to be deenergized placing it in a safe conditionp The main steam isolation valves and recirculation loop sampic valves were already shut; +

thus, doenergizing the circuit had no effect except interrupting power to the relay. A new relay was inctalled and checked for proper operation.

We are enclosing twenty-five copics of this letter.

Very truly yours, g B303310459 720626 -

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DR ADOCK 05000 gjgn , ,a .),nMg)

Ivan R. Finfr, , J/. ,

Manager, Nuclear Generating Stations IRF/pk Enclosures 3576 cc: .Mr. J. P. O'Reilly, Director

, Regulatory Operations,= Region'I L _

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