ML20050B266

LER 82-006/01T-0:on 820311,type B & C Valve Leakage Tests Exceeded Tech Spec Limits.Caused by Corrosion.Svc Air Check Valves Disc Replaced & Valve Cover Remachined

ML20050B266
Person / Time
Site:	Point Beach
Issue date:	03/25/1982
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20050B265	List: ML20050B264 ML20050B266
References
LER-82-006-01T, LER-82-6-1T, NUDOCS 8204050155
Download: ML20050B266 (3)

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EVENT DESCHIPTION AND PROB ABLE CONSEQUENCES o 2 l Review of Unit 1 Type "B" & "C leakage tests on 03/11/82 revealed that; on two occasions one valve had leakage such that the limit in TS g o 3 g o 14 ; [15.4.4.III.B was exceeded. During the 1979 refueling, the check valve l o ,, g(2-C) in the service air line to containment leaked 160 L/ min. During g "B" RCP a n [the 1980 refueling, the check valve (755B) in the CCW line to ,

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ATTACHMENT TO LICENSEE EVENT REPORT NO. 82-006/0lT-0 Wisconsin Electric Power Company Point Beach Nuclear Plant, Unit 1 Docket No. 50-266 On March 11 during the review and assemblage of 10 CPR 50 Appendix J, Type "B" and "C" testing data, it was discovered that on two occasions the combined leakage of the Type "B" and "C" tests exceeded Technical Specification 15.4.4 III.B acceptance criteria of 0.45 Lp. On each occasion, the Technical Specification acceptance criteria was violated because of gross leakage through one of the containment isolation valves. In addition, an investi-gation into the subsequent reporting of these events revealed that past reports have not been filed in strict accordance with the applicable Technical Specifications.

The first event occurred during the Unit 1 refueling outage in 1979. Operations refueling test ORT #49 revealed that the Unit 1 service air supply containment isolation valve (a Powell 4", 150 lb., carbon steel check valve) was leaking at 160,000 cc/ minute. The valve disc was replaced and valve cover remachined.

After the maintenance, leakage measured was 20 cc/ minute.

The second event occurred during the Unit 1 refueling outage in 1980. Operations refueling test ORT #69 revealed that the containment isolation valve in the component cooling water line to the Unit 1 "B" reactor coolant pump was leaking at 194,000 cc/ minute (a Velan 4", 150 lb., carbon steel check valve). The valve seat and disc were relapped. After the maintenance, leakage measured was 530 cc/ minute. The leakage was found during refueling testing and all repairs were made prior to system heatup.

In both cases, the as-found leakage of the subject valves was the major cause of exceeding 173,330 sec/ minute, which is the acceptance criteria in Technical Specification 15.4.4.III.B for the integrated Type "B" and "C" testing program.

In both cases, the exact cause of the valve degradation is not known. However, it appears that sealing surface corrosion was responsible for the excessive valve leakages.

At no time was the public health and safety jeopardized, as in each case the combined Type "A", "B", and "C" leakage was below the values assumed in the safety analysis report and the maximum allowable leakage established in Technical Specification 15.4.4.I.B.

The non-reporting of these events was an administrative oversight. The method used in tracing the overall Type "B" and "C" leakage incorporates the use of a computer. In these two events, the repaired leakage was used to update the running total of the Type "B" and "C" testing program, instead of using the as-found

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r Icakage. The method incorporated in tracking the total Type "B" and "C" Icakage is being changed to ensure timely identification and reporting of events exceeding the Technical Specification allowables.

It should be noted that the required 24-hour written notification of this event was made on March 12.

The Resident Inspector has been notified of this event.

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