ML19274F046

Forwards LER 79-009/03L-0

ML19274F046
Person / Time
Site:	Cooper
Issue date:	05/22/1979
From:	Lessor L NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19274F047	List: ML19274F046 ML19274F048
References
CNSS790235, NUDOCS 7906080255
Download: ML19274F046 (3)

Text

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COOPER NUCLEAR ST ATioN g P.o. Box 98, B ROWN VILLE, NE BR ASKA 68321 Nebraska e.u bl.ic Power Distr.ic t ------ ---

1cLemoNe om .2s.ae n CNSS790235 May 22, 1979 Mr. K. V. Seyfrit U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region IV 611 Ryan Plaza Suite 1000 Arlington, Texas 76011

Dear Sir:

This report is submitted in accordance with Section 6.7.2.B.2 of the Technical Specifications for Cooper Nuclear Station and discusses a reportable occurrence that was discovered on April 30, 1979. A licensee event report form is also enclosed.

Report No.: 50-298-79-9 Report Date: thy 22,1979 Cccurrence Date: April 30, 1979 Facility: Cooper Nuclear Station Brownville, Nebraska 68321 During the April 1979 refueling outage, all primary containment double "0" ring seals, testable expansion bellows, electrical penetrations, and testable isolation valves were tested in accordance with Technical Spec ifications Section 4. 7. A.2. f and Tables 3.7. 2 through 3. 7. 4. This report describes a condition which may have resulted in the limiting condition for operation established in Section 3.7.A.2 of the Technical Specifications. There were a total 47 Type "B" penetrations and 46 Type "C" penetrations tested. There were 4 Type "C" penetrations that were found to be leaking above established limits which necessitated repair and retest. Leak rate limits for each penetration are arbitrary limits established from the preoperational local leak rate test results. No electrical penetrations, double "0" ring seals, or testable bellows wert  ;

leaking excessively. Listed is a sucacry of each primary containment penetration which was repaired due to a high leakage rate.

X-10 RCIC Turbine Steam Supply line, RCIC-MO-15 (inboard isolation valve) and RCIC-MO-16 (outboard isolation valve)

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Mr. K. V. Seyfrit May 22, 1979 Page 2.

Initial leakage was found to be 2135.5 scfh. The established limit was 2.0 scfh. Investigation showed RCIC-MO-16 not fully shut. The torque switch was replaced on the motor operator. After repair of RCIC-MO-16 the leak rate was reduced to 1.24 scfh. RCIC-MO-15 was not repaired or adjusted. Therefore, primary containment would have been maintained by the inboard isolation valve RCIC-MO-15. The leaking valve is an Anchor 3" gate valve with a Limitorque motor operator.

X-205 Purge and Vent Supply to the Suppression Chamber, PC-233 MV (inboard isolation valve) and PC-237 AV (outboard isolation valve)

Initial leakage was found to be 80.5 s:fh. The established limit was 5.0 scfh. PC-233 MV and PC-237 AV we.e disassembled and the rubber seating rings were replaced. Af te- repair of PC-233 MV and PC-237 AV the leak rate was reduced to .34 scfh. PC-233 MV and PC-237 AV are Allis-Chalmers 24" b'utterfly valves.

X-205 ACAD Purge Supply line to the Suppression Chamber, ACAD-1303 MV (out-board isolation valve) and ACAD-1304 >N (inboard isolation valve)

Initial leakage was found to be 72.7 scfh. The established limit was 0.1 scfh. ACAD-1303 MV was found to be not shutting tightly. The torque switch on the operator was cleaned and adjusted. After adjust-ment of ACAD-1303 MV the leak rate was reduced to .07 scfh. ACAD-1304 MV was not repaired or adjusted. Therefore, primary containment would have been maintained by the inboard isolation valve ACAD-1304 MV. The leaking valve is an Anchor 1" gate valve with a Limitorque operator.

X-212 RCIC Turbine Exhaust to the Suppression Chamber, RCIC-15 CV and RCIC-37 The test volume for this penetration is between RCIC-15 CV and RCIC-37.

RCIC-37 is a manually operated globe stop check valve. Initial leakago  ;

was found to be 33.9 scfh. The established limit was 1.0 scfh. Both RCIC-15 CV and RCIC-37 were disassembled for repair and it was found the seating surfaces were rough. The seate were lapped on both valves.

Af ter repair of both valves the leak rate was 4.4 scfh. Even though the leakage was above the established limit, further repair was not init-iated because of the safety margin in the established limits. RCIC-15 CV is an Anchor 8" swing check valve. RCIC-37 is an Anchor 8" globe stop check valve.

Mr. K. V. Seyfrit May 22, 1979 Page 3.

Thirteen Type "B" penetrations were tested which had not previously been tested. These penetrations were identified in LER 78-30. All 13 pen-etrations tested satisfactory with zero leakage.

All test volumes were tested at greater than 58 psig and pressure decay or water collection was used to determine the leak rate. The total uncontained, as found, leakage was less than 230.44 scfh or 3.84 scfm.

This leakage is less than 1/47. of the capability of the standby gas treatment system. The total leak rate after repair was reduced to 120.44 scfh.

Sincerely, h .-

L. C. Lessor Station Superintendent Cooper Nuclear Station LCL:cg Attach.

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