05000298/LER-1979-034, Forwards LER 79-034/03L-0

Forwards LER 79-034/03L-0

ML19256G541
Person / Time
Site:	Cooper
Issue date:	12/06/1979
From:	Lessor L NEBRASKA PUBLIC POWER DISTRICT
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19256G542	List: 05000298/LER-1979-034, Forwards LER 79-034/03L-0 05000298/LER-1979-034-03, /03L-0:on 791107,base for Diesel Generator 2 Lube Oil Header to Cam Chain Tensioner Broke.Caused by Hose Proximity to Cam Chain & Tensioner Sprocket.Hose Replaced & Clamped Away from Cam Chain
References
CNSS790637, NUDOCS 7912310447
Download: ML19256G541 (2)

LER-1979-034, Forwards LER 79-034/03L-0

Event date:
Report date:
2981979034R00 - NRC Website

text

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COOPER NUCLEAR STATeoN P.O. Box 98, BRoWNVILLE, NE DR ASKA 68 321 Nebraska Publ.ic Power D. tr. t TELEP-oNE em 423 3.n is ic CNSS790637 December 6, 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 November 7, 1979. A li-censee event report form is also enclosed.

Report No.:

50-298-79-34 Report Date:

December 6, 1979 Occurrence Date: November 7, 1979 Facility:

Cooper Nuclear Station Brownville, Nebraska 68321 Identification of Occurrence:

A condition which may have led to operation in a degraded mode permitted by a limiting condition for operation as delineated in Section 3.9.B.3 of the Technical Specifications.

Conditions Prior to Occurrence:

Steady state power operation at approximately 98% reactor power.

Description of Occurrence:

During the annual inspection of the No. 2 diesel generator, a woven wire lube oil hose that feeds the can shaft chain tightener was found broken.

Designation of Apparent Cause of Occurrence:

The apparent cause of the hose failure was that the hose had been positioned too close to the cam chain tightener sprocket.

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Mr. K. V. Seyfrit December 6,1979 Page 2.

Analysis of Occurrence:

During operation of the diesel generator, the hose was caught in the sprocket which caused the hose to be ripped from the connection to the lube oil header.

Failure of this hose may have prevented long term operation of the diesel.

It is not known the length of time the hose had been broken since the last annual inspection but there had been sufficient lubri~ cation for the cam chain tightener since the hose broke.

The hose connection to the lube oil header is orificed which prevented loss of lube oil to the other lubri-

~

cating points.

In the event this hose would have caused a diesel generator failure, the No. 1 diesel was operable.

This occurrence presented no adverse consequences from the stand-point of public health and safety.

Corrective Action

The affected cam chain tightener and cam chain were inspected and there was no abnormal wear present. With the concurrence of the diesel generator manufacturer, the hose and the connection to the lube oil header for No. 2 diesel generator were replaced and a clamp was installed anchoring the hose away from the can chain tightener sprocket. The same hose on No. 1 diesel generator was inspected an no abnormalities were noted. A clamp was also in-stalled on No. 1 diesel generator to prevent the occurrence of a similar event.

Sincerely,

~

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

1657 174