ML17272A461

Deficiency Rept on 780413:defective Solder Connections on Electrical Penetrations X100,A,B,C & D.Reported on 790504. Repair & QC Procedures Provided by Westinghouse

ML17272A461
Person / Time
Site:	Columbia
Issue date:	05/31/1979
From:	WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
Shared Package
ML17272A460	List: ML17272A458 ML17272A461
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 7906080313
Download: ML17272A461 (2)

Text

Attachment G02-79-110 REPORTABLE DEFICIENCY AND CORRECTIVE ACTION MPPSS NUCLEAR PROJECT NO. 2 DEFECTIVE TERMINATIONS ON ELECTRICAL PENETRATIONS lrlASHINGTON PUBLIC POllER SUPPLY SYSTEM DOCKET NO. 50-397 LICENSE NO. CPPR-93 Descri tion of Deficienc Defective solder connections were found on pin connectors on pene-trations X100, A, B, C, and D. The defects consisted of cold solder joints and lack of adequate solder. The deficiency was noted (April 13, 1978 and documented at the time by a Nonconformance Report (NCR). The NCR was dispositioned April 24, 1978 with corrective procedures provided by the manufacturer. On May 4, 1979, the subject was reported as a deficiency under 10CFR50.55(e) to Region V of the NRC.

Anal sis of Safet Im lications The referenced penetrations interconnect the following incore neutron monitoring sensors with their respective conditioning equipment: average power range monitors (APRM), intermediate range monitors (IRM) and source range monitors (SRM). A degraded solder connection for the APRM's and SRM's does not present a safety problem as the failure would be detectable and be in the safe direction. However, with the IRM's, it is conceivable that an increase in resistance across a cold solder connection could go undetected and provide an output that would be in the inverse of the actual output, thus not providing an input to the reactor protection system (RPS) as required.

Corrective Action Taken The disposition of the NCR include repair and quality control procedures which were provided by Westinghouse to the site organization that will perform the work.

The subject defects are not generic in nature. However, the affect to other facilities is not known.

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