ML20070A686

Part 21 Rept Re Failure of 4.16 Kv vertical-lift Switchgear Cell Mounted,Auxiliary Contacts to Operate on Demand During Testing of Auxiliary Standby Switchgear at Facility. Initially Reported on 901101.New Test Link Sent to Facility

ML20070A686
Person / Time
Site:	Callaway
Issue date:	01/17/1991
From:	David Jones GENERAL ELECTRIC CO.
To:	Baker E Office of Nuclear Reactor Regulation
References
REF-PT21-91 NUDOCS 9101250069
Download: ML20070A686 (1)

Text

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GE Power Dolivery

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January 17, 1991 Subjects GE magne-blast Circuit Breakers 4.16 kV Switchgear 4t Callaway Nuclear Generating Station Union Electric Co.

Cell Mounted Auxiliary switch Failure Due to Bending of Breaker Operating Cam During Maintenance Further to My Letter of November 1, 1990 to James Taylor, Director NRC Mr. Edward Baker, Acting Branch Chief Vendor Inspection Branch U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Dear Mr. Baker We received a report on October 26, 1990 of the failure of 4.16kV vertical-lift switchgear, cell mounted, auxiliary contacts to operate on command during the testing of auxiliary stand-by switchgear at Callaway Nuclear Generating Station by Union Electric Co.; this was reported in my letter of November 1, 1990.

The purpose of my letter of November 1, 1990 was to inform your office that we are treating this deviation as reportable under 10 CFR Part 21; it will be given industry notice this weak via the INPO network in a "Significant Event Report" (SEN). We will also be issuing a service advice letter in a timely manner.

We havo provided a prototype redesigned test link to the Callaway Station and we await final feedback from Union Electric's engir.eering unit. We believe that the original design of the test link, coupled with less than optimum maintenance practices was the root cause of the problem.

We shipped commercial grade material to Union Electric to correct this situation within one week of notification of the problem. We will continue to inform you and our customers of further pro,reso and recommendations.

Again, this condition can only exist where liconeees have optional cell mounted auxiliary switches, use the optional maintenance test link, and where the link has been adjusted without clearance so ao to apply excessive operating force.

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Dean dones [

Product Manager, Breakers ,

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