ML19309F175

Forwards LER 80-007/03L-0

ML19309F175
Person / Time
Site:	Cooper
Issue date:	03/25/1980
From:	Lessor L NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19309F176	List: ML19309F175 ML19309F181
References
CNSS800194, NUDOCS 8004280574
Download: ML19309F175 (2)

Text

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Jy ;j m Nebraska Public Power District o CNSS890194 March 25, 1980 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 March 10, 1980. A licensee event report form is also enclosed.

Report No.: 50-298-80-07 Report Date: March 25, 1980 Occurrence Date: March 10, 1980 Facility: Cooper Nuclear Station Brownville, Nebraska 68321 Identification of Occurrence:

A condition which could have resulted in operation in a dagraded mode permitted by the limiting condition for operation es:ablished in Section 3.4. A.1 of the Technical ?rscifications.

Conditions Prior to Occurrence:

The reactor was shutdown and vented. Removal of fuel frr m the reactor was in progress. (The 19?d Refueling and Mainte'iance Outage started on March 1, 1980.)

Description of Occurrence:

During surveillance testing of the Standby Liquid Contrcl Pumps, SLC Pump "1B" would pump only 36.5 gpm at 1220 psig. The Technical Specifications require the SLC System to provide 38.2 gym at 1215 psig from each pump.

Designation of Apparent Cause of Occurrence:

Wear and pitting to the seating surfaces of the internel suction and discharge valves allowed backward leakage in the pomp through the suction valve and thus reduced the flow provided b; SLC Pump Q~),

"1B". 3 lb l

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s Mr. K. V. Seyfrit March 25, 1980 Page 2.

Analysis of Occurrence:

The Standby Liquid Control Pump "lB" is one of two redundant pumps used to inject boron into the reactor to shutdown the reactor during emergency conditions (such as failure of the CRD System).

Each pump is tested monthly to verify operability and capacity as required by the Technical Specification. During performance of Surveillance Procedure 6.3.8.2, Standby Liquid Control Pump Op-erability Test, Pump "1B" provided only 36.5 gpm at 1220 psig which did not meet the Technical Specification for SLC flow capacity of 38.2 gpm at 1215 psig. The internal suction and discharge valves for SLC Pump "lB" were removed and inspected revealing wear and pitting on their seating surfaces. This wear to the valve seats was caused by normal pump operation and allowed backward leakage from the pump through the suction valve reducing the capacity of the pump.

Redundant SLC Pump "1A" tested at the same time did provide a flow capacity in excess of Technical Specification requirements and was therefore operable. The reactor was in cold shutdown and vented and removal of the fuel from the core was in progress. At the time of the occurrence, the SLC System was not required to be operable by the Technical Specifications. This occurrence presented no adverse consequences from the standpoint of public health and safety.

Corrective Action:

The SLC pump is a type TD-60 TRIPLEX manufactured by Union Pump Company. The internal suction and discharge valves seating sur-faces were machined as recommended by the pump instruction manual and reinstalled in the pump. The surveillance procedure for pump operability was run again and a capacity of 52 gpm at 1220 psig was attained by SLC Pump "1B" satisfying Technical Specification Sec-tion 4.4. A.2.b for SLC System capacity.

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

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