ML19261A705

LER 79-001/03L-0 on 790105:during Normal Operation,Failure of Inverter 4 Interrupted 120V Vital AC Power to Channel D Components.Inverter Malfunction Caused by Failure of Several Capacitors (C1) & Oscillator Board (SC1-PL-1163)

ML19261A705
Person / Time
Site:	Millstone
Issue date:	02/02/1979
From:	Bates R NORTHEAST UTILITIES
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML19261A702	List: ML19261A701 ML19261A705
References
LER-79-001-03L, LER-79-1-3L, NUDOCS 7902060296
Download: ML19261A705 (1)

Text

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Ia 2 l During routine power operation, the failure of inverter No. 4 resulted in an The ,

,o 3 l interruption of 120 volt vital AC power to channel D RPS and ESAS cc -ponents.

g io a l channel D RPS trips for High Power, local Power Density, High Pressurizer Pressure I and High Containment Pressure, and the ESAS trip for High Containment Pressure were ,

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.o 3 disabled, were subsequently inhibited and operation continued in accorJance with _ ,

3 action 3.3.2.1, ia 7 l Technical Specifications Section 3.3.1.1, Table 3.3-1, Action 2b, and Inverter: Solid State Controls, Inc.; Model SV12150/TS-150NB.

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, , l ferring .the vital AC to the alternate source, until th'e inverter was fully deenergized. ,

1 3 l The voltage surge following the delayed transfer caused failures of several components ;

i 4 I in the channel D RPS and ESAS cabinets which were replaced and operation continued. g 80 7 8 9 STA US  % POWER OTHER STATUS IS OV RY DISCOVERY OESCRIPTION i 5 LE_j@ l 1 l 0 l 0 l@l NA l [A_j@l Operator observation [

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, Y) 1 StJE E CHiPTION 7QQ a 68 69 CO-e 8 9 10 R. U. Bates . 203/447-1791