ML20003C394

AO 50-219/74/17:on 740307,power Operation Continued W/Sb Startup Transformer Unavailable for Svc for Time Period Greater than Tech Specs Limits.Caused by Failure of Cam Switch Contacts.Corrective Action to Be Determined

ML20003C394
Person / Time
Site:	Oyster Creek
Issue date:	03/08/1974
From:	Roni A JERSEY CENTRAL POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
AO-50-219-74-17, NUDOCS 8103030487
Download: ML20003C394 (3)

Text

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3/P/74 Occurrence:

1700 OYSTER CITlil: SUC1. EAR GENElt\\ TING STATION FOPKED RIVER, Nill JERS!!Y 03731 Abnormal Occurrence Report No. 50-219/74/ 17 IDENTir1CKrION Violation of the Technical Specifications, paragraph 3. v.13, OF OCCUhkENCE:

when potter cperation af the reactor continued with the Su transforr.cr unavailable for service for a tir.e period preater tha; the Technical Specification limit of 7 days out of any 30 day period.

This event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph _ 1 j sr.

CONDIT1C:iS PRIOR TO OCLUMPJiNCE:

Steady State Power X _ Routine Shu.down 110 Standby Operation

_ _ Cold Shutdown Load Changes During Refueling Shutdown Routine Pewer Operation Routine Startup Other (Specify)

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Opeic. tion Powcr:

Elce., M 00 FVe 1

Reactor, ~300 1i.;t Flow:

Recire.,

7.5 x 10" ppm Feed., 1.2 x 10' lb/hr Stad; Gas:

=10,000 pCi/sec DESCRIPi10N On Thursday, liarch 7,1974, at 1700, as part of the roetine OF OCCURRENCE:

plant shutdown procedure, it was required to transfer pinnt power from the IP> auxiliary transformer to the SD startup transformer. The control room operator on duty operated the closing switch for the S1B hrtaker with no results. The reactor shutdown was tercinated, holding the generator c]ectric po. cr at approxinately 100 We in order to maintain a power supply path throur.h the IB au.xiliary transforrer.

Inspect ion Qw9 P00R BRIGINAI.

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.AhnO1Fal Occurrenc:.

Reli.)i't ;o..Yv-219/7 ;/17 Page 2 of the SIB breaker revealed that the closin; spring was not in the wound 1 osition; hence, breaker closure was not possible in either the nanual or autonatic node. Tne failure of the spring to wind has been traced to a failed spring cam switch t.hich closes when the sprin:; unuinds.

'lhe cau swit ch clo'ure normally causes a relay, 52'.',

to energi:e which in tum deene raiter the SIB breaker closing coil 52X, contacts freu 52X in t urn cause the spring winding notor to start ard re. ind the spring.

Since the cart switch contacts failcd to cause 52Y to energue, a con-tinuous current ucs npplied to 52X causin.o it to burn thich resulted in freezing the coil au.xiliary contacts in their energized position.

It is thought at this tire that the failure of the spr.ing to rewind occurred during th. Ja:tuarj 12,197' reactor shutdown operation, since this uns the Inst "ccessful operation of the breaker.

After replacing the 52X coil and the failed contact in the can switch, successful transfer of load frora IB ouxiliary transforr.er to the SD startup transformer was cchieved.

APPARENT CAUSE Design Proce.!ure OF OCCUP.PECE:

Manufacture th1 usual Service Co.udition Installation /

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Inc. Environnental

' Construction

_ Cc.ponent Failure Operator Other (Specify)

The failure of the cam switch contacts is presently uader investigati on.

P00R ORlGlNM

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Abriamel Octurrence Pey ort No. 50-219/74/17 Page 3 ANALYSIS OF The SIB breaker is intended to close tuto:r.ct i cally when the OCCURRiiSCE:

IB auxiliary t ransformr breaker trips. Ilad the brecker been required to perform this function, it would have resulted in a loss of power to the In and ID 4160 volt swi t ch gear. The 1-2 l'rcrgency Dic;cl Cencrator would have initiated in the fast start r. ode and assumed loud on the 1D ema gency bus.

CORRECTIVE The corrective action will bc deterniaed after PCaC evaluatien ACTIO":

of the incident.

FAILURE DATA:

1-!anufacturer data pertinent to the failed suitch:

General Electric Company Switch Part #456-A666S-5 4160V Seit ch. car t

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Prepared by: [.[g,M : vi,

/n.g Date:

3/8/74 P00R ORIGINAL

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