ML19256E030

LER 79-036/03L-0:on 791004,control Element Assembly 1 Dropped to Bottom of Core.Caused by Oscillation in 15-volt Power Supply,Resulting in Dip of Output Voltage & Decreasing Holding Current of Upper Grimper

ML19256E030
Person / Time
Site:	Calvert Cliffs
Issue date:	10/19/1979
From:	Bauer E, Lagiewski J BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19256E024	List: ML19256E023 ML19256E030
References
LER-79-036-03L-01, LER-79-36-3L-1, NUDOCS 7910250322
Download: ML19256E030 (1)

Text

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EVENT DATE 14 75 REPORT DATE 'O 7 8 60 61 DOCKET NuveER EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h 101 1 l Durina routine oneration control element asso-bly-01 dennend tn thn 1 0 3i [ bottom of the core at 0228. Per the reouirements of T.S. 3.1.3.1.f. I l 0 l41 ] reactor cower was reduced to 4 70% at 0310. At 0328, control i IOlsi eierent assembly-01 was restored to alianment with other CEA's I iOisi lof its crouo. LER's 79-24 (U-2) and 78-48 (U-1) describe similiar 1 0 7 levents. I o a I

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CAUSE DESCRIPTION AND CORREC'IVE ACTIONS i o lit is surroised that a t'orentarv oscillation in the reculatorv rortion of tha i, i, i [15V power sucolv cau3,{the outout voltaae of the oower suoplv to din somewhat I ii ,, j lbelcw 15V D.C. thus decreasino the "holdino" curren+ nf the rFa 'e n n n o ,- I

, 3 larioper. At this t;jme FCR 78-72 which adds redundant nnwer eunnlie<: with w I

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PERSONNEL E XPCsynES NU98 E R TYPE DESCRIPTION -

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