ML19256E473

LER 79-055/03L-0:on 790930,channel a Lower Positive Power Distribution Setpoint Found Decreasing.Caused by end-of-life Type Failure of Adjustment Potentiometer of Dual Potentiometer/Buffer Module Model 384612-01

ML19256E473
Person / Time
Site:	Calvert Cliffs
Issue date:	11/02/1979
From:	Heibel R, Rizzo P BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256E472	List: ML19256E471 ML19256E473
References
LER-79-055-03L, LER-79-55-3L, NUDOCS 7911070481
Download: ML19256E473 (1)

Text

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. . _ . . LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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• 60 61 COOK ET NUP/8 ER 68 69 EVENT DATE EV ENT CESCRIPTION AND P ACB ABLE CONSECUENCES~h 3121 l Durino routine oower observatinn tha enntrn1 onn- neer3ter nntad +83+ l o ;3 the Channel A Lower Positive Power Distribution sarnnint was da c ran c i n n I o A Channel A Hich Power Level. Therral Marnin/ Low Prassura and Avial 1 ois L wer trip units cre bypas ed oer T.S. '.3.1.1 action 2 and tha +rin I o e setpoint returned to the correct value. inis is nnt a ranatitiva I o , ; occurr?nce. All trip units were returned to service on October 1, I o e 1979 at 1115. 80 I

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(,y_j@ ( Njh 43 4 FI a ofnlh 47 33 34 35 42 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i C l Found faulty Dual Potentiometer /Buffar un dulp f un dal t'oa619 n1) which I 1

, i affects positive slope 3 sional within Axial Power Drawer. Failt e is I

, ,  ; considered to be a natural end of life tvoe of fa.E re a dit mndula's 1 2 l adjustrent notentiometer. No oreventive action 9 daa-ad nar w a rv

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3 9 80 STA L NPO?.ER CTHER STATUS htSCOV RY CISCOVERY CESCRIPTION i s [gj@ l - ninl@lN/A lA l@[_p jerator Observatinn l ACTIVITY CO?, TENT AvouNT On ACTiviTv @ LOC ATiON Os aEtEASE @

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