ML20235Y481

Part 21 Rept Re Cracked Welds Discovered on Striker Plates of GE Circuit Breakers.Initially Reported on 890130.GE Advised Util That Striker Plates Subj to Impact Loading Only When Breaker in Racked Out & Operated in Test Position

ML20235Y481
Person / Time
Site:	Wolf Creek
Issue date:	03/03/1989
From:	Withers B WOLF CREEK NUCLEAR OPERATING CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-89, REF-PT21-89-045-000 PT21-89-045-000, PT21-89-45, WM-89-0063, WM-89-63, NUDOCS 8903140190
Download: ML20235Y481 (2)

Text

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1 W$t.F CREEK NUCLEAR OPERATING CORPORATION Bart D. Withers Precedent and Wof Em@re Omcor March 3, 1989  ;

1 WM 89-0063 U. S. Nuclear Regulatory Commission  ;

ATTN: Document Control Desk l Mail Station P1-137 )

. Washington, D. C. 20555

Reference:

Letter ET 88-0177 dated November 18, 1988 from J. A. Bailey, WCNOC, to R. D. Martin,.NRC  ;

Subj ect: Docket No. 50-482: Additional Information Regarding IC CFR 21. Notification Concerning Genera 1' Electric Magne-Blast Circuit Breakers .{

Gentlemen:

l This letter is.being submitted to provide additional information requested ]

by D. Pickett and P. Kadambi of the NRC in a telephone call to Wolf Creek j Nuclear Operating Corporation (WCNOC) on January 30, 1989. This information j concerns cracked welds discovered on striker plates of 4160V General i Electric (G.E.) Magne-Blast type AM-4.16-350-2H circuit breakers.  !

The information supplied by WCNOC in the reference 10 CFR 21 notification was based on available information at the time of the submittal, some of which was supplied by G.E. during the initial investigation of the problem.

It was determined that the welds had insufficient strength to resist impact leads during breaker operation. WCNOC repaired the welds on all safety related G.E. Magne-Blast breakers prior to startup following the refueling j outage.

On January 13, 1989, G.E. initiated a telecon with WCNOC to discuss the breaker striker plates. During this discussion G.E. indicated that the striker plate is subject to impact loading only when the breaker is racked out and operated in the test position. Although WCNOC has not verified the accuracy of this information, if the striker plate is not impacted during breaker operation with the breaker racked in, then the deficient weld should have no impact on the ability of the breaker te open or close to fulfill its intended function as long as the striker plate remains attached. Since the welds have been repaired at Wolf Creek, WCNOC has no plans to address the affect of this defect on the Seismic Qualification of the breakers or the affect of a dislodged striker plate within the operating mechanism. I 9g3 3 _

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I I P.O. Box 411/ Burlington, KS 66839 / Phone: (316) 364-8831 .

4 An Equal opportunity Employer INF/HCNET

l 1 . , .;

• *' "WM 89-0063 Page 2 of 2.

March 3 , 1989 If you have any questions concerning this matter, please contact me or Mr. O. L. Maynard of my staff.

Very truly yours, Bart D. Withers President and Chief Executive Officer BDW/j ad cc: B. L. Bartlett (NRC)

E. J. Holler (NRC)

R. D. Martin (NRC)

D. V. Pickett (NRC)

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