ML20125C853

Forwards LERs 79-094/03L-0,79-095/03L-0 & 79-096/03L-0

ML20125C853
Person / Time
Site:	Arkansas Nuclear
Issue date:	01/04/1980
From:	Trimble D ARKANSAS POWER & LIGHT CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20125C855	List: 05000368/LER-1979-094-03, /03L-0:on 791207,during Mode 1 Operation,Channel B Pressurizer Pressure Variable Setpoint Oscillated Between 0 & 1,000 Psia,Causing Low Pressurizer Pressure Trip on Channel B.Caused by Power Supply Failure.Card Replaced 05000368/LER-1979-095-03, /03L-0:on 791211,during Mode 1 Operation,Battery Charger 2D32 Discovered to Have Low Output Voltage,Rendering Bus Inoperable.Caused by Current Surge While Readjusting Output Voltage.Ac Breaker Reset & 2D32 Returned to Svc 05000368/LER-1979-096-03, /03L-0:on 791211,during Mode 1 Operation,Core Protection Calculator C Failed,Causing Low DNBR & High Linear Power Density Trips.Caused by Data Link Failure Between Calculator & Operator Console.Sys Restarted ML20125C853
References
2-0520, 2-520, NUDOCS 8001110587
Download: ML20125C853 (1)

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ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK, ARKANSAS 72203 (501) 371-4000 January 4, 1980 2-010-2 Mr. K. V. Seyfrit, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Conmission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011

Subject:

Arkansas Nuclear One - Unit 2 Docket No. 50-3G8 License No. NPF-6 Licensee Event Report Nos.

79-094/03L-0, 79-095/03L-0 and 79-096/0?L-0 (File:

2-0520) l Gentlemen:

In accordance with Arkansas Nuclear One - Unit 2 Technical Specification 6.9.1.9.b, attached are the subject reports concerning a lov.> pressurizer pressure trip (79-094/03L-0), an inoperable DC bus train (79-095/03L-0) and the inoperability of a core protection calculator channel (79-096/03L-0).

Very truly yours, A ONtd 0 T k David C. Trimble Manager, Licensing DCT: MAS:skm Attachments cc:

Mr. Norman M. Haller, Director Mr. Victor Stello, Jr., Director Office of Management and Office of Inspection and Program Analysis Enforcement U. S. Nuclear Regulatory Comm.

U. S. Nuclear Regulatory Comm.

Washington, D. C.

20555 Washington, D. C.

20555 Mr. W. D. Johnson U. S. Nuclear Regulatory Comm.

P. O. Box 2090 Russellville, AR 72801 90022297 8 00111 o f8 7 MQMBER MtDOLE SOUTH UTILITIES SYSTEM

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