05000361/LER-1982-089, Forwards LER 82-089/03L-0.Detailed Event Analysis Submitted

Forwards LER 82-089/03L-0.Detailed Event Analysis Submitted

ML20065A751
Person / Time
Site:	San Onofre
Issue date:	09/03/1982
From:	Ray H SOUTHERN CALIFORNIA EDISON CO.
To:	Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
Shared Package
ML20065A753	List: 05000361/LER-1982-089, Forwards LER 82-089/03L-0.Detailed Event Analysis Submitted 05000361/LER-1982-089-03, /03L-0:on 820812,discrepancy Noted Between as-built Software & Core Protection Calculator Functional Requirement,Involving Penalty Errors Associated W/Failed Calculators.Caused by Software Error.Software to Be Changed
References
NUDOCS 8209140102
Download: ML20065A751 (2)

LER-1982-089, Forwards LER 82-089/03L-0.Detailed Event Analysis Submitted

Event date:
Report date:
3611982089R00 - NRC Website

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Southern California Edison Company

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September 3, 1982 U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596-5368 Attention:

Mr. R. H. Engelken, Regional Administrator

Dear Sir:

Subject: Docket No. 50-361 30-Day Report Licensee Event Report No.82-089 San Onofre Nuclear Generating Station, Unit 2 Pursuant to Section 6.9.1.13a of Appendix A, Technical Specifications to i

Operating License NPF-10 for San Onofre Unit 2, this submittal provides the required 30-day written report and copy of Licensee Event Report l

(LER)82-089 for an occurrence, involving the Core Protection Calculator (CPC).

l The NSSS Vendor, CE Power Systems recently revealed to SCE a discrepancy between the "as-built" software and CE's functional requirements for the CPC.

Recent testing of CPC's at another plant has revealed that the appropriate Local Power Density Penalty Factor (LPD PF) is not applied when Control l

Element Assembly Calculators (CEAC's) both send " fall" signals, or one sends " fall" signal and the other is placed in a test status. The SONGS l

2 CPC software has this same condition.

This is not a safety concern as other factors will cause a plant trip in almost all plant operating conditions. Certain initial conditions involving low power operation would not experience a trip, but at these low powers, a trip is not necessary for plant safety. A formal, documented, confirmatory analysis of this will be available about September 30, 1982.

8209140102 820903

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PDR ADOCK 05000361 N -29 S

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4 R. H. Engelken September 3, 1982 Modifications to the software to correct this condition will be accomplished at a future date. The schedule for this modification has not been established.

If there are any questions, please contact me.

Sincerely, d.

l y

Enclosure:

LER 82-089 cc:

A. E. Chaffee (USNRC Resident Inspector, San Onofre Unit 2)

U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement O. S. Nuclear Regulatory Commission Office of Management information and Program Control Institute of Nuclear Power Operations