ML19254E511

LER 79-031/03L-0:on 790930,control Element Assembly Motion Inhibit Circuit Declared Inoperable Following Loss of Metrascope Indication of Control Element Assembly Position. Caused by Metrascope Component Failure

ML19254E511
Person / Time
Site:	Millstone
Issue date:	10/25/1979
From:	Bates R NORTHEAST UTILITIES
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19254E498	List: ML19254E497 ML19254E501 ML19254E511
References
LER-79-031-03L, LER-79-31-3L, NUDOCS 7911010408
Download: ML19254E511 (1)

Text

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61 DOCK E T .N UMB E H EVE NT OATE HEPOa T DAT E EVENT DESCHIPTION AND PRO 9ABLE CONSEOUENCES h Ia 2 1 During routine operations, the CEA Motion Inhibit (CMI) circuit was declared I

! O l 31 l inoperable following a loss of metrascope indication of CEA position. In accordance [

O ,; g with technical specifications, section 3.1.3.1.b all CEA's were maintained fully l

[o ,o i i withdrawn and the CEA Drive System mode switch maintained in off. tihen metrascope  ;

o g j l repairs were completed the Cf1I was restored to operability. Total time out of  ;

,o;,y ; service was 7 days. l 10 a l z I 8 9 LO DE CODE S 3C E CC 'PDNENT COD 5 Sus 5 Su OOs 10 o g

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O l The loss of CEA position indication was due to a metrascope component failure. I ii i l The faulty part, an operational amplifier (UA747-14 pin chip) in the clock-amplifier i 3, ,, y j card, was replaced and metrascope indication and Ct1I operability were both restored. i

,,,3,  ; The requirements of Technical Specification 3.1.3.3 for CEA position were complied [

g , g i ; with during this event.  ;

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