ML20027A258

Forwards LERs 78-004/03L-0,78-005/03L-0,78-006/03L-0 & 78-007/03L-0

ML20027A258
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/13/1978
From:	David Williams ARKANSAS POWER & LIGHT CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20027A259	List: 05000368/LER-1978-004-03, /03L-0:on 780916,during Mode 3 Operation,Prior to Initial Criticality,Autotransformer Tripped from Timed Overcurrent.Caused by Feeding Both Unit Auxiliary Loads After Unit 1 Reactor Trip.Overcurrent Adjusted 05000368/LER-1978-005-03, /03L-0:on 780916,during Mode 3 Operation Prior to Initial Criticality,Onsite AC Power Distribution Sys Deenergized.Caused by Bus Feeder Breakers Tripping on Low Voltage Due to Overloading.Setpoints Adjusted 05000368/LER-1978-006-03, /03L-0:on 780916,during Mode 3,prior to Initial Criticality,Raw Water Tank Level Dropped Below Tech Specs. Caused by ECCS Actuation Due to Loss of Relay Power to ECCS Components & Inverter Failure.Tank Level Increased 05000368/LER-1978-007-03, /03L-0:on 780917,RCS Chloride Concentration Reduced to Less than 0.15ppm.Engineering Evaluation Determined Condition Should Have No Effect on Structural Integrity of RCS Based on out-of-limit Condition ML20027A258
References
FOIA-79-149 NUDOCS 7811060145
Download: ML20027A258 (1)

Text

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v ARKANSAS POWER & LIGHT COMPANY POST OFFICE BOX 551 LITTLE ROCK. ARKANSAS 72203 (501)371-4000 October 13, 1978 2-108-6 Mr. K. V. Seyfrit, Director Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011

Subject:

Arkansas 1 e - Unit 2 Docket Nof. 50-968)

License NbT NPF-6 Reportable \\ ccurrence 0

Report Nos. '50-368/78 a,-

50-368/78-5, 50-368/78-6 and 50-368/78-7 (File:

2-0520) i Gentlemen:

In accordance with Arkansas Nuclear One - Unit 2 Techriical Specification 6.9.1 9, we have attached four (4) Reportab.le Occurrence Reports concerning:

the los3 of two independent off site power source = (78-4); AC Electrical buses n,o.t.

operable (78-5); the RWT level being less than the m,inimum required (78-6); and the Chloride concentration being out of limits (78-7).

As committed, we have also enclosed a-description of the sequence of events that transpired.on-September 16, 1978, associated with the above occurrences.

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Very truly yours, Daniel H. Williams Manager, Licensing DHW:REI:mh Attachments v m '. e 5 o t e 6 MEMBEA MtOOLE SOUTH UTIUTIES SYSTEM