ML19323B047

Interim Deficiency Rept Re GE 4160 Volt Circuit Breaker Limit Switches.Various Switches on Several Breakers Became Loose During Operation.Caused by Backing Out of Mounting Screws

ML19323B047
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	03/05/1980
From:	Novarro J LONG ISLAND LIGHTING CO.
To:
Shared Package
ML19323B043	List: ML19323B047
References
SNRC-466, NUDOCS 8005090164
Download: ML19323B047 (2)

Text

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• H IC K SVI LLE. NEW YORK 11801 Direct Dial Number SNRC-466 March 5, 1980 Mr. Boyce H. Grier Office of Inspection and Enforcement, Region 1 U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 LONG ISLAND LIGHTING COMPANY SHOREHAM NUCLEAR POWER STATION - UNIT 1 DOCKET NO. 50-322

Dear Mr. Grier:

On February 6,1980, in accordance with 10CFR50.55 (e), we reported verbally to Region 1 a deficiency with limit switches associated with General Electric 4160 volt circuit breakers.

This letter serves as our 30 day written report of this deficien.cy.

Description of Deficiency The 4160 vole circuit breakers are General Electric type 1200 and 2000 ampere magne-blast breakers with ML-13 mechanisms, as manufactured by GE in their Philadelphia facilities . I During field checkout of the subject circuit breakers, it was I noted that various limit switches on several breakers had become loose during operation of the breakers. T'.te breakers had been recently returned by GE after rework for other I deficiencies (Ref. SNRC-335 November 17, 1978). Those breakers i surveyed and found to have this deficiency had undergone an l average of 32 to 125 operations since their return to Shoreham. l The loose switches were caused by backing out of the mounting screws, presumably a result of shock or vibration caused by the breaker operation. This enabled the limit switches to back away from their operating levers and permitted the limit switch contacts to return to their normally open state. The resulting loss of continuity in the breaker control would result in the inability of the breaker to close.

' March-5, 1980

'Mr. Boyce H. Grier Page two '

This deficiency was noted on safety and non-safety related breakers. However, circuit breakers presently installed in non-safety related cubicles have been qua_ified for Category I use, and therefore, circuit breaker substitutions may be made.

Routine breaker inspections do not require limit switch inspection.

Failure of a Category I breaker to close will prevent actuation of safety related equipment.

Corrective Action General Electric engineering and quality assurance have been apprised of this problem.

Since final corrective actions have not been developed at this time, a supplemental report will be submitted in 90 days. Final Corrective Action, Corrective Action to Prevent Recurrence and Date of Full Compliance will be provided at that time, i Very truly yours, rrdwo

. P. Novarro roject Manager Shoreham Nuclear Power Station MAG /mc cc: Mr. Victor Stello, Director NRC Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.C. 20555 cc: Mr. J. Higgins Site NRC Trailar 1

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