05000311/LER-1982-145, Forwards Corrected LER 82-145/03X-1.Detailed Event Analysis Encl

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Forwards Corrected LER 82-145/03X-1.Detailed Event Analysis Encl
ML20070M885
Person / Time
Site: Salem PSEG icon.png
Issue date: 01/11/1983
From: Midura H
Public Service Enterprise Group
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20070M887 List:
References
NUDOCS 8301250367
Download: ML20070M885 (3)
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LER-2082-145, Forwards Corrected LER 82-145/03X-1.Detailed Event Analysis Encl
Event date:
Report date:
3112082145R00 - NRC Website
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text

e O PSEG Public Service Electric and Gas Company P.O. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station January 11, 1983 Mr. R. C. Ilaynes Regional Administrator USNRC Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406 Dear Mr. Ilaynes LICENSE NO. DPR-75 DOCKET NO. 50-311 REPORTABLE OCCURRENCE 82-145/03L ,

This letter is to correct errors in previously submitted

. Licensee Event Report 82-145/03L-(the report was erroneously distributed as LER 82-146/03L). The corrected report is attached.

Sincerely yours, l 1:fibu<-.J H. J. Midura General Manager -

Salem Operations RF:kls J CC: Distribution glho O S

The Energy People pd W 2189 (20M) 1181

Repott Number: 82-145/03L Report Date: 12-15-82 Occurrence Date: 11-29-82 Facility: Salem Generating Station Unit 2 Public Service Electric & Gas Company Hancock's Bridge, New Jersey 98038 IDENTIFICATION OF OCCURRENCE:

Reactor Coolant System Subcooling Margin Monitor - Inoperable.

This report was initiated by Incident Report 82-495.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 - RX Power 81% - Unit Load 910 MWe, DESCRIPTION OF OCCURRENCE:

At 0747 hours0.00865 days <br />0.208 hours <br />0.00124 weeks <br />2.842335e-4 months <br />, November 29, 1982, following a shift of No. 2B Vital Bus power source in preparation for planned maintenance on No. 1 Station Power Transformer, the Control Room Operator observed that the P-250 Computer had shut down. Since it utilizes computer data points and memcry, the Reactor Coolant System (RCS) subcooling margin monitor was declared inoperable and Technical Specification Action Statement 3.3.3.7a was entered.

RCS wide range temperature and pressure indication were available throughout the occurrence, allowing calculation of the subcooling

) margin through the use of steam tables.

APPARENT CAUSE OF OCCURRENCE:

Investigation revealed that a failure of the computer inverter power l supply had occurred, and the computer had apparently shifted to the l backup supply off of No. 2B Vital Bus. Transferring No. 2B Bus power source caused a momentary loss of power which resulted in a shutdown

(

of the computer, including the drum mass storage device.

l I Further investigation showed that the loss of the inverter was due to I

a failed oscillator circuit board. Following repair of the inverter, attempts to start the drum device were unsuccessful, however.

Inspection revealed that the air pressure to the drum heads was low.

The pressure had apparently decreased slightly during operation; it was sufficient while the drum was running but was not high enough for j starting the device. No cther problems were evident, and no recent l failures of these types were noted. The occurrence was therefore l assumed to be of an isolated nature.

ANALYSIS OF OCCURRENCE:

Operability of the accident monitoring instrumentation ensures that I sufficient information is available on selected plant parameters to l

l l

[

LER 82-145/03L ANAI?fSIS Of_.QCCFRRENCE: (cont'd) monitor and assess these variables following an accident. Since, as noted, wide range RCS temperature and pressure instrumentation was operable, allowing determination of the subcooling margin, the events involved no risk to the health and safety of the public. The occurrences constituted operation in a degraded mode permitted by a limiting condition for operation and are reportable in accordance with Technical Specification 6.9.1.9b.

Action Statement 3.3.3.7a requires:

With the number of operable accident monitoring channels less than the required number of channels, restore the inoperable channel (s) to operable status within 7 days, or be in at least hot shutdown within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

CORRECTIVE ACTION:

The failed circuit board was replaced, and the inverter power supply was regained. The drum head air supply regulator was adjusted for the proper pressure, and the device was restarted. The P-250 computer was returned to operation, and no further problems were observed. The RCS subcooling monitor was declared operable, and Action Statement 3.3.3.7a was terminated at 2030 hours0.0235 days <br />0.564 hours <br />0.00336 weeks <br />7.72415e-4 months <br />, November 29, 1982. No other corrective action was deemed necessary in view of the nature of the problem.

FAILURE DATA:

Solid State Controls, Inc.

10 KVA Inverter ^

Oscillator Printed Circuit Board Folio No. V081D Prepared By R. Frahm b1P[b Gen 6ral Manager -

Salem Operations SORC Meeting No.82-110

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