05000298/LER-1980-028, Forwards LER 80-028/03L-0

Forwards LER 80-028/03L-0

ML19331E041
Person / Time
Site:	Cooper
Issue date:	08/11/1980
From:	Lessor L NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19331E042	List: 05000298/LER-1980-028, Forwards LER 80-028/03L-0 05000298/LER-1980-028-03, /03L-0:on 800713,while Increasing Power During Normal Operation,Ge Reactor Vent Monitor Failed Downscale. Caused by Two Failed Capacitors.New Capacitors Installed & Unit Returned to Operable Status
References
CNSS800457, NUDOCS 8009050260
Download: ML19331E041 (2)

LER-1980-028, Forwards LER 80-028/03L-0

Event date:
Report date:
2981980028R00 - NRC Website

text

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- Q COOPER NUCLEAR STATtoN

.'i X Nebraskas Public Power District

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'a=51 CNSS800457 August 11, 1980 Mr. K. V. Seyfrit U.S. Nuclear Regulatory Commission Office 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.2 of the Technical Specifications for Cooper Nuclear Station and discusses a reportable occurrence that was discovered on July 13, 1980. A licensee event report form is also enclosed.

Report No.:

50-298-80-28 Report Date:

August 11, 1980 Occurrence Date: July 13,1980 Facility:

Cooper Nuclear Station Brownville, Nebraska 68321 Identification of Occurrence:

A condition occurred which lead to operation in a deg ndeo mode as permitted by Table 3.2.D of the Technical Specifications.

Conditions Prior to Occurrence:

i Routine power operation with the plant power at approxirmtely 97%

1 thermal power.

Description of Occurrence:

A downscale alarm occurred on the General Electric Reactor Building Vent Monitor, RMP-RM-452A.

l Designation of Apparent Cause of Occurrence:

The cause for the downscale reading was due to low voltage from the power supply. The power supply was checked and two electrolytic capacitors were found defective.

It is believed that the subject capacitors failed due to aging.

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Mr. K. V. Seyfrit August 11, 1980 Page 2.

Analysis of Occurrence:

The function of the Reactor Building Vent Monitor, RMP-RM-452A, is to monitor exhaust air for airborne radiation. The radiation reading was normal prior to and during this failure as indicated by the redundant system that was operable at the time af this occur-rence. This occurrence presented no adverse potential consequences from the standpoint of public health and safety.

General Electric SIL No. 290 describes a failure mechanism for electrolytic capacitors and recommends testing that can be per-formed to detect deterioration. However, the testing had not been performed on these capacitors because it requires unsoldering and resoldering connections which can also lead to potential problems.

Corrective Action

The two electrolytic capacitors that failed were replaced and the unit was placed back into service. The correroonding capacitors in the redundant channel will be removed and checked during the next quarterly surveillance test.

Tested capacitors will be installed.

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

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