05000311/LER-1982-116, Forwards LER 82-116/03L-0.Detailed Event Analysis Encl

Forwards LER 82-116/03L-0.Detailed Event Analysis Encl

ML20065S946
Person / Time
Site:	Salem
Issue date:	10/20/1982
From:	Midura H Public Service Enterprise Group
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20065S948	List: 05000311/LER-1982-116, Forwards LER 82-116/03L-0.Detailed Event Analysis Encl
References
NUDOCS 8211020107
Download: ML20065S946 (3)

LER-2082-116, Forwards LER 82-116/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3112082116R00 - NRC Website

text

A o O PSEG Public Service Electric and Gas Company P.O. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station October 20, 1982 Mr. R. C. Haynes Regional Administrator USNRC Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Haynes:

LICENSE NO. DP R-75 DOCKET NO. 50-311 REPORTABLE OCCURRENCE 82-116/03L Pursuant to the requirements of Salem Generating Station Unit No. 2, Technical Specifications, Section 6.9.1.9.b, we are submitting Licensee Event Report for Reportable Occurrence 82-116/03L. This report is required within thirty (30) days of the occurrence.

Sincerely yours, ll, Wwb ' ' ' '

H. J. Midura General Manager -

Salem Op,erations RF:ks f CC: Distribution 8211020107 821020 PDR ADOCK 05000311 S PDR The Energy People N OS 2189 (20M} 1181 L

• i Report Number: 82-ll6/03L Report Date: 10-20-82 Occurrence Date: 09-27-82 Facility : . Salem Generating Station, Unit 2 Public Service Electric & Gas Company Hancocks Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Reactor Coolant' System Subcooling Margin Monitor - Inoperable.*

This report was initiated by Incident Reports82-310 and'82-313.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 - Rx Power 82% - Unit Load 900 MWe.

DESCRIPTION OF OCCURRENCE:

At 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />, September 27, 1982, during routine operation, the Control Room Operator observed a malfunction of the P-250 process computer. The computer was declared inoperable, and because it supplies the inputs to the Reactor Coolant System (RCS) subcooling margin monitor, the monitor was also declared inoperable. Technical Specification Action Statement 3.3.3.7.a was entered retroactive to the time of discovery of the problem.

I The computer was repaired and the subcooling monitor satis-i factorily tested. At 0815 hours0.00943 days <br />0.226 hours <br />0.00135 weeks <br />3.101075e-4 months <br />, September 28, 1982, the monitor j was declared operable, and Action Statement 3.3.3.7.a was terminated.

Later that day, at 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br />, the Control Room Operator observed that the subcooling monitor had failed for a second time. The j instrument was declared inoperable and Action Statement 3.3.3.7.a was re-entered.

RCS wide range temperature and pressure indication were available i throughout both occurrences, allowing calculation of the subcooling i margin through the use of steam tables.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

On the first occasion, the malfunction of the P-250 computer resulted from failure of a computer logic board. No recent failures of the type of board involved had been observed, and the incident was assumed to be an isolated one.

LER @2-ll6/03L 4 DESIGNATION OF APPARENT CAUSE OF OCCURRENCE: (continued)

In the second instancg, Thermocouple T0045A (Tsat) was found to be indicating 1300 F. A new value was entered, the channel was reset, and the thermocouple indication returned to normal.

No further problems with the Tsat indication were noted. The computer had not been flushed during maintenance following the first occurrence; the failure apparently involved an isolated malfunction of the point associated with the repair.

ANALYSIS OF OCCURRENCE:

Operability of the accident monitoring instrumentation ensures that sufficient information is available on selected plant parameters to monitor and assess these variables following an accident. Since, as noted, wide range RCS temperature and pressure instrumentation was operable, allowing for determination of the subcooling margin, no risk to the health or safety of the public was involved. The occurrence constituted operation in a degraded mode permitted by a limiting condition for operation, and is reportable in accordance with Technical Specification 6.9.1.9.b.

Action Statement 3.3.3.7.a 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:

In the first case, the failed logic board was replaced and the computer was satisfactorily tested. As noted, the subcooling margin monitor was declared operable on September 28, 1982.and Action Statement 3.3.3.7.a was terminated. In the second instance, as discussed, a value was entered into the point and the point cleared to restore the Tsat input. At 1929 hours0.0223 days <br />0.536 hours <br />0.00319 weeks <br />7.339845e-4 months <br />, September 28, 1982, the subcooling monitor was declared operable and Action Statement 3.3.3.7.a was terminated. No further action was deemed necessary in view of the nature of the occurrence.-

FAILURE DATA:

Westinghouse Electric Corp.

PRODAC 250 Computer Logic Board Prepared By R. Frahm Mh[s Gsnerhl Manager -

Salem Operations

, SORC Meeting No.82-94B

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