ML20004D666

LER 81-033/03L-0:on 810427,helium Circulator 1C Speed/Wobble Modifier Malfunctioned Causing Loss of Plant Protective Sys Functions to High Speed Trip Circuits.Caused by Electronic Circuit Unbalance.Spare Speed Element Installed

ML20004D666
Person / Time
Site:	Fort Saint Vrain
Issue date:	05/27/1981
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20004D656	List: ML20004D655 ML20004D666
References
LER-81-033-03L, LER-81-33-3L, NUDOCS 8106090631
Download: ML20004D666 (1)

Text

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? 8 68 NUMSER 68 69 EVENT OATE tVENT DESCRIPTION AND PROSABLE CONSEQUENCES h l o 12 l l A malfunction of helium circulator 1C speed modifier caused loss of olant protective j g o ,3, l system function of high speed trips to one of three channels. Reportable per Fort St.l f to64l I Vrain Technical Specification AC 7.5.2(b)2 operation under a degraded mode of l 3 a ,3 ; lLC0 4.4.1, Table 4.4-3. No affect on plant operation. Probable consequence was loss l 1o is l I of high speed circulator trip function to one of three channels. Redundant system j i o 17 I I available and operable. No affect on public health or safety. Similar reports l l

,g,,,  ; RO 78-15, RO 79-41, and R0 80-71. l 60 7 8 9 0E Cc0E S SC E COMPCNENT CODE SL8 COD'E S E loisi 7 8 lIl B l@ W@ lE l@ l Il Nl Si Tl Rl Ul@ l T l@ lz lh 9 10 it 12 13 18 19 20 SEQUENTIAL QCOURAENCE REPORT REVtSION ggnino EVENT YE A R REPORT No. CCOE TYPE No.

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1 01 32 T N AC o C P NT ME HOURS SS I FOR 8. SUP LIE MANUFAC RER lx l@lz l@ l zi@ LIJ@ l 01 01 01 01 I vi@ l42N I@ l43Ni@ Ic 12 19 1047l@

33 34 JS M 31 40 44 44 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS lilol l General Atomic. Cocmany circulator soeed/ wobble modifiers caused a loss of olant pro- I t i ii l l tective system functions to high speed trip circuits due to electronic circuit un- I

,,,,, l balance caused by a resistance change in -he speed element cable assembly. Installed I i,,3, [ spare speed element and cable connected and speed modifier balanced. Nuclear Projects l

,, ,4j l Department is ar.aly::ing the problem to determine if new cables are needed. I 7 8 9 30 A  % power OTHER STATUS CI O RY OlSCoVfRY CESCRIPTioN Ii l 5* l l E l@ l0 l 5 10 lhlN/A l l" Alhl" Ooerator Observation l

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'ISCRIPTICN D @ 8106090(3/ '

NRC USE ONLY ,

L11o_JLslE81 N/A I ItIt!II!'!!!Ii WNXO 83 ECF96VSE3 [ PHONE:

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