05000335/LER-1979-025-03, /03L-0 on 790720:variable High Power Trip Setpoint in Core Protection Calculator Failed to Track Reactor Power. Caused by Power Supply in Core Protection Calculator Failing Due to Filter Capacitor Failure

/03L-0 on 790720:variable High Power Trip Setpoint in Core Protection Calculator Failed to Track Reactor Power. Caused by Power Supply in Core Protection Calculator Failing Due to Filter Capacitor Failure

ML17266A091
Person / Time
Site:	Saint Lucie
Issue date:	08/17/1979
From:	Schoppman M FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML17207A322	List: 05000335/LER-1979-025, Forwards LER 79-025/03L-0 05000335/LER-1979-025-03, /03L-0 on 790720:variable High Power Trip Setpoint in Core Protection Calculator Failed to Track Reactor Power. Caused by Power Supply in Core Protection Calculator Failing Due to Filter Capacitor Failure
References
LER-79-025-03L, LER-79-25-3L, NUDOCS 7908300711
Download: ML17266A091 (1)

LER-1979-025, /03L-0 on 790720:variable High Power Trip Setpoint in Core Protection Calculator Failed to Track Reactor Power. Caused by Power Supply in Core Protection Calculator Failing Due to Filter Capacitor Failure

Event date:
Report date:
3351979025R03 - NRC Website

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~10 Ouring power reduction, the variable high power trip setpoint on channel "C" in the core protection calculator failed to track reactor power.

~03 Action in accordance with Technical Specification 3.3.1.1 was initiated.

A;0 5 volt power supply was repaired and the channel restored to operable condition within the time 'limit s ecified.

There was no adverse affect

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Three channels remained operable and no additional action

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The variable high power trip setpoint did not track the power level reduc-tion due to a failed power supply in the core protection calculator.

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failed because of a failed filter capacitor.

The cause of. the capacitor failure is not known.

The most probable cause is normal end of life of an electronic component.

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