ML17266A141

LER 80-003/03L-0:on 800106,during Normal Operations,Control Element Assembly 30 Reed Switch Indication Channel Failed, Eight Days After Repair for Same Problem.Cause Unknown;Will Be Investigated During Refueling Outage

ML17266A141
Person / Time
Site:	Saint Lucie
Issue date:	02/05/1980
From:	Schoppman M FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML17207A831	List: ML17207A830 ML17266A141
References
LER-80-003-03L, LER-80-3-3L, NUDOCS 8002210378
Download: ML17266A141 (3)

Text

NRC FORM 366 U. S. NUCLEAR RKCULATORY COMMISSION g 77)

LICENSEE EVENT REPORT

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CONTROL BLOCK: I Ql (PLEASE PAINT OR TYPL'LL RKOUIAEO INFORMATION)

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QQCKET NUMSER 44 EVENT CATE 14 IS ASSORT QA E 40 Q

EVENT OKSCRIPTION ANO SRQBABLK CONSKOUEiNC'KS QIO Durin normal o erations CEA 30 reed swi tch os i ti on indi cati on channel

~03 failed. The channel was declared INOPERABLE. In accordance with TS 3 w withdrawn i i n once er 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> at this position. The channel was repaired and returned to service. This channel failed a ain 8 da s after returnin to service.

~07 The same action er TS 3.1 3.3 was a ain erformed but the channel has no

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~08 been re aired et. This is the first event of this t e.

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0 The cause of these channel fail es 's tiall re aired b re lacin a shorted this was the second s are cable that was tried the channel remained failed when the first s are cable was installed . The channel failure cause and re air will be investi ated durin the 1980 refueling outage.

9 9 FACILITY METIIOQ OF OTIIEA STATUS P/

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~ ERSQNNEL INIURIES

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' M. A. Schoppman PH0NE: 305 552-3802 800$ BEO

4 Reportabl e Occurrence 335-SO-3 Licensee Event Report Pa e Two Additional Event Description and Probable Conse uences During normal 100K power operation, CEA 830 reed switch position indication channel failed. The channel was declared INOPERABLE. In accordance with Technical Specification 3.1.3.3, CEA 830 was withdrawn to the Upper Electric Limit position (" Full Out"), CEA 430 was verified at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> at this position as power operation continued. Eleven days later, following an unrelated plant trip, investigation of the cause for the channel failure seemed to .ndicate a shorted power cable in the vicinity of the reactor vessel head. This cable was replaced with a spare cable, but the failed channel remained INOPERABLE. A second spare cable was installed and thy channel became operable. The channel was successfully tested for satis'factory operation and declared OPERABLE. The plant was started up and returned to 100Ã power operation.

Eight days after returning this channel to OPERABLE status, it failed again.

The same appropriate actions stated above were performed again. CEA 430 reed switch position indication channel is presently INOPERABLE.

CEA 830 is in regulating CEA group number 1 which is not used for power shaping. Also, it is the last regulating group to move during insertion.

Therefore, CEA $ 30 can be maintained fully out at the Upper Electric Limit without any effect on operations or group alignment. All CEA's were trippable during the event.

This problem will be investigated and resolved during the refueling outage scheduled Harch 15, 1980 or prior to restarting from any unplanned outage, whichever is first.