ML20084E208

AO 50-244/74-09:on 740530,during Surveillance Test PT-9, One Underfrequency Relay on Bus 11A Failed to Transmit Signal of Simulated Fault Condition.Relay Replaced

ML20084E208
Person / Time
Site:	Ginna
Issue date:	05/30/1974
From:	Platt C ROCHESTER GAS & ELECTRIC CORP.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20084E207	List: ML20084E206 ML20084E208
References
AO-50-244-74-09, AO-50-244-74-9, NUDOCS 8304140437
Download: ML20084E208 (1)

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ROCHESTER GAS f.!!D ELECT.?!C CORPORATION e 69 EAST AVEllUE, RCCHESTER. N.Y.14649 Ginna Station , ,,u..,

May 30, 1974 ^". m m 2700 Mr. James P. O'Reilly, Director [ .._~[ ^

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Directorate of "egulatory Operations '

Region 1 U.S.A.E.C.

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631 Park Avenue King of Prussia, Pennsylvania 19406 g6 W d

Subject:

Abnor-al Occurrence 74-9: Failure of Underfrequency E.

Relay During Surveillance Test 6Af h,. A f/

I \c; Ginna Station Docket 50-244

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Dear Mr. O'Reilly:

This is to confirn c.y convercation with Mr. A. D. Davis today to report Abnorn.a1 occurrence 74-9 at Ginna Station.

During the norning of May 30, 1974, while conducting the routine Monthly PT-9 Surveillance Test (Periodic Test - Undervoltage and Underfrequency Protectica 11A and lin - 4160 Volt Busses) one of the underfrequency relays ec. ::.c. 11.'. hu faild to tran:rit a rian:1 t^ the ' "O " a d a "l* "

i a fa"1" condition was being sinulated. This failure defeated one of the two channels of redundancy provided for underfrequency protection o,f this bus.

Inc faulty relay was replaced with a sparc relay. The spare relay vaa tested satisfactorily and declared operable at 1125 on May 30, 1974.

Very truly yours, j, C. f4w Charles E. Platt Superintendent CEP:bg --

xc :.lMr. _J . F. O ' Leary , AEC Mr. G . J . Swar thou t , RCLE L-rp.

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