ML20023D997

Updated LER 83-013/03X-1:on 830211,power Lead from Welding Machine Became Disconnected & Grounded to Torus Base Metal Causing Arc Strike Which Fused Copper/Brass Into Metal. Cause Considered accident.W/830523 Ltr

ML20023D997
Person / Time
Site:	Dresden
Issue date:	05/23/1983
From:	Scott D, Tang Wee D COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
83-509, LER-83-013-03X, LER-83-13-3X, NUDOCS 8306060232
Download: ML20023D997 (3)

Text

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EVENT OESCRIPTION AND PACSASLE CCNSECLENCES h 10 l 2 l l During refueling operations withweld reinforcement in progress inside the torus, a l lal3; j power lead from a welding machine became disconnected and grounded to torus base l l C l 41 l metal on bottom of Bay 6 causing an arc strike which fused copper / brass into the l l0isil metal. Two additional arc strikes requiring repair were also observed in other bavst 10 !s l l These events are of minimum safety sinnificances since the unit was in cold shutdownl 1017l l and minimum wall thickness of the torus was maintained. There was no effect on l ICi;lI public health or safety. First occurrence of this tyre ne nrnmann_ l r 7 3 3 30 SYSTE\t CAUSE CALSE OVA wAL,E 000E COOE 3USCOOE CCYPONENT CODE SUSCOOE SUSCODE IOl2l 7 3 Is IA l h (Lj h [Ej h l VI El Sl Sl El Ll h d h d h 3 to ?1 12 13 18 13 JJ

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' . % Comm:nwraith Edison Drtsd n Nuclear Power Station R R. #1 Morris, Illinois 60450 Telephone 815/942-2920 May 23, 1983 DJS Ltr #83-509 James G. Keppler, Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 Updated Reportable Occurrence Report #83-13/03X-1, Docket #050-237 is being submitted to your of fice in accordance with Dresden Nuclear Power Station Technical Specification 6.6.B.2.(b), conditions leading to operation in a degraded mode permitted by a limiting condition for operation or plant shutdown required by a limiting condition for operation. This report revises the event description and provides corrective actions taken to repair arc strikes on the base metal of the torus.

N .Mh D.J. Scott b Station Supt intendent Dresden Nuclear Power Station DJS/kjl Enclosure cc: Director of Inspection & Enforcement Director of Management Information & Program Control U.S. NRC, Document Management Branch l

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83 - 22 PART I l TITLE OF EVENT OCCURRED ARC Strikes Inside Torus 2-11-83 2100 DATE TIME REASON FOR SUPPLEMENTAL REPORT This report revises event description and provides description of corrective actions.

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DATE 5/13f73 7' SUPPLEMENTAL REPORT APPROVED

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