05000336/LER-1979-030-03, /03L-0:on 790929,engineered Safety Feature Channel a Sensor Cabinet Trip Bistables All Tripped Due to Loss of Power.Caused by Failed Overvoltage Protector on Channel A-15 Volt Power Supply,Causing Fuse to Blow.Parts Replaced

/03L-0:on 790929,engineered Safety Feature Channel a Sensor Cabinet Trip Bistables All Tripped Due to Loss of Power.Caused by Failed Overvoltage Protector on Channel A-15 Volt Power Supply,Causing Fuse to Blow.Parts Replaced

ML19254E501
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: 05000336/LER-1979-030-03, /03L-0:on 790929,engineered Safety Feature Channel a Sensor Cabinet Trip Bistables All Tripped Due to Loss of Power.Caused by Failed Overvoltage Protector on Channel A-15 Volt Power Supply,Causing Fuse to Blow.Parts Replaced 05000336/LER-1979-031-03, /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 ML19254E497
References
LER-79-030-03L, LER-79-30-3L, NUDOCS 7911010401
Download: ML19254E501 (1)

LER-1979-030, /03L-0:on 790929,engineered Safety Feature Channel a Sensor Cabinet Trip Bistables All Tripped Due to Loss of Power.Caused by Failed Overvoltage Protector on Channel A-15 Volt Power Supply,Causing Fuse to Blow.Parts Replaced

Event date:
Report date:
3361979030R03 - NRC Website

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flEPORT DATE B0 EVENT DEscillPTION AND PHO9 ABLE CONSEQUENCES h lo l 21 ' During routine plant opr 1tions the Engineered Safety Features (ESF) channel A sensor 1

j o l3 l l cabinet trip bistables all tripped due to a loss of powere In accordance with technica1l lo i,i i specificatior.s, section 3.3.2.1.b,~ the channel A ESF bistables were inhibited and I

g o j o; i plant operation continued while the failure was investigated and repaired.

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o is ; 1 out of service was 17 hours1.967593e-4 days <br />0.00472 hours <br />2.810847e-5 weeks <br />6.4685e-6 months <br />.

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