ML19249C779

LER 79-074/03L-0:on 790821,during Mode 1,core a Projection Computer Trips Bypassed,Allowing Change Out of Power Supplies & Causing Erroneous Position Indication Inputs.Core a Projection Computer Supplies Replaced

ML19249C779
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/12/1979
From:	Shively C ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19249C777	List: ML19249C776 ML19249C779 ML19249C781
References
LER-79-074-03L, LER-79-74-3L, NUDOCS 7909180492
Download: ML19249C779 (1)

Text

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NRC FORM 366 U. 5. NUCLE AR REGUL ATORY COMMISSION 17 77)

LICENSEE EVENT REPORT EXHIBIT A CONTROL BLOCK: l (PLE ASE PRINT OR TYPE ALL REQUIRED INFORMATION1 i

l l l l ! lh e o i A R l Al Nj 0 l2 lgl 010 l -l0 l 0 l 0l 0l O j- l 0 ]O lgLKLNat teCE NSE Nuv6E84 26 20 l1 l ivri 1 l1JJ l 1biCATbe lg[ l ;g 3 8 9 LICEN5E E CODt 1. 15 C ON'T A ,"I'!% LL_J@l0 i s p 10 i o is i 6 l sigl 0l 8 l 2 l1 l 7 l 9l@l 0l 9 l1 l 2 l 7 l980l@ J8 I 8 6G 65 Docat?Nuwgga te 69 tvtNT DATE #$ HFPOstTOATE EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES Oio o 2 1 Durinn Mode 1 operation, the "A" CPC trips were bypassed to  ;

o 3 1 allow the change out of the RSPT power supplies which ,

lo 1 1 I were causine erroneous position indication inputs to the l n s i CPr. The pulse counter from CEAC #2 and the upper  ;

lo p l I electrical limits were available for CEA position indications.

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[ There have been no similar occurrences. This occurrence is ,

o , i related to LER 50-368/79-073. Reportable per T.S.6.9.1.9b. "

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C AUSE CESCR " TION AP.D CORREC HVE ACTIONS h o The "A" CPC was taken out of service as a precautionary ,

, , i step during the maintenance activity in the CPC i i 2 1 cabinet. The PSPT wwer supplies were chanced out and i gii3i i the "A" CPC was returned to service within three hours l g I meeting the reouirements of Action Statenent T.S. Table 3.3-1 Action 2a. ;

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