ML19317F459

RO 270/76-13:on 761014,valve LPSW-5 Found Inoperable.Caused by Defective Electrical Contact.Contact on B Finger Cleaned

ML19317F459
Person / Time
Site:	Oconee
Issue date:	11/12/1976
From:	DUKE POWER CO.
To:
Shared Package
ML19317F454	List: ML19317F453 ML19317F459
References
RO-270-76-13, NUDOCS 8001140693
Download: ML19317F459 (1)

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• -DUKE POWER COMPANY OCONEE UNIT 2 Report No.: R0d70/76-13 Report Date: November 12, 1976 Occurrence Date: October 14, 1976 4 Facility: -Oconee Unit 2, Seneca, South Carolina Identification of Occurrence: Defective electrical contact resulting in inoperable valve LPSW-5 Conditions Prior to Occurrence: Unit at 61 percent full power Description of Occurrence:

On October 14, 1976, while testing valve LPSW-5, it was determined that the electrically operated Limitorque valve could not be opened from the normal control switch in the Control Room. As required by Ocot.ee Technical Specification 3.3.7 the operability of the redundant valve, LPSW-4, was verified. The dirty electrical contact causing the problem was cleaned and LPSW-5 was tested and returned to service within the period allowed by Technical Specification 3.3.5.

Designation of Apparent Cause of Occurrence:

The incident was caused by a dirty electrical contact on the "B" finger of the l

closing coil of the Motor Control Center which energized LPSW-5.

Analysis of Occurrence:

Valve LPSW-5 supplies cooling water to the "B" low pressure injection cooler.

In the event of an ES actuation, the redundant valve, LPSW-4, would have supplied cooling water to the "B" LPI cooler as required. It is considered that due to l

L the brief period of time 'during which LPSW-5 was declared inoperable and the operability of.the redundant valve, that the health and safety of the public I was not affected by this occurrence.

Correc'tive' Action:

l The "B" finger on the closing coil in the Motor Control Center was cleaned.

It is considered that yearly preventive maintenance and monthly ES tests are sufficient to detect and prevent similar problems associated with ES Limitorque valves.

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