ML19344E024

Forwards LER 80-026/03L-0

ML19344E024
Person / Time
Site:	Cooper
Issue date:	07/30/1980
From:	Lessor L NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19344E025	List: ML19344E024 ML19344E031
References
CNSS800451, NUDOCS 8008260529
Download: ML19344E024 (2)

Text

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COOPER NUCLEAR $7ATioN

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CNSS800451 July 30, 1980 Mr. K. V. Seyfrit U.S. Nuclear Regulatory Commission Of fice of Inspection and Enforcement Region IV 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011

Dear Sir:

This report is submitted in ,accordance with Section 6.7.2.B.3 of the Technical Specifications for Cooper Nuclear Station and discusses a reportable occurrence that was discovered on July 1,1980. A licensee event report form is also enclosed.

Report No.: 50-298-80-26 Report Date: July 30, 1980 Occurrence Date: J uly 1, 1980 Facility: Cooper Nuclear Station Brownville, Nebraska 68321 Identification of Occurrence:

A condition occurred which resulted in operation in a degraded mode permitted by the limited condition for operation establis*ed in Section 3.6.C.2 of the Technical Specifications.

Conditions Prior to Occurrence:

The reactor was operating at a steady state power level of approx-imately 92% of rated power.

Description of Occurrence:

During routine measurement of identified reactor leakage in the drywell, equipment drain sump flow instruments were found to be inoperable.

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9 Mr. K. V. Seyfrit July 30, 1980 Page 2.

Designation of Apparent Cause of Occurrence:

Instrument failure. The flow recorder had a damaged slide wire and the power supply had a blown fuse.

Analysis of Occurrence:

Identified reactor coolant leakage is determined by measuring the quantity of liquid pumped from the equipment drain sump. The flow measuring equipment (recorder and integrator) was found inoperative on July 1, 1980. Troubleshooting of the equipment revealed a broken recorder slide wire and a blown fuse in the power supply.

The latter fault was likely a result of the former. The cause of the broken slide wire is attributed to component age.

During this event, backup detection for small coolant leaks in the drywell was provided by an alarm associated with the frequency of -

ope. ration of the equipment drain sump pump. Also, a crude estimate of the leakage could have been made by monitoring the vaste col-lector tank level change while pumping the sump.

Corrective Action:

The slide wire and fuse were immediately replaced. The equipment was tested with satisfactory performance and the system was re-turned to service.

Sincerely, L. C. Lessor

Station Superintendent Cooper Nuclear Station l

LCL:cg Attach.

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