ML20093A412
| ML20093A412 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 07/03/1984 |
| From: | Tramm T COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 84-04, 84-09, 84-4, 84-9, 8927N, NUDOCS 8407100468 | |
| Download: ML20093A412 (2) | |
Text
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/n'N Commonwealth E' son j
) One First National Plaza. Chicago. Ilknoes i
C Address Reply to. Post Office Box 767
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Chicago, lihnois 60690 July 3, 1984 Mr. James G. Keppler, Regional Administrator U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Elly, IL 60137
Subject:
Byron Generating Station Units 1 & 2 Braidwood Generating Station Units 1 & 2 Westinghouse Motor Control Centers NRC Docket Nos. 50-454, 50-455, 50-456, and 50-457
Dear Mr. Keppler:
On June 1, 1984 Commonwealth Edison Company notified Mr. Robert Lerch of a deficiency apparently reportable pursuant to 10 CFR 50.55(e) regarding spot-welded electrical connections in Westinghouse motor control centers at both Byron and Braidwood stations.
This letter provides an interim report to satisfy the 30-day report requirement.
For NRC tracking purposes this deficiency is numbered 84-04 for Byron and 84-09 for Braidwood.
Description of Deficiency During routine maintenance of 480 volt circuit breakers within a Westinghouse 5 star series motor control center, a questionable connection was identified on the wire that runs between the breakers and the 480 volt bus.
The wire has a lug at the breakers end.
At the other i
cnd the wire is spot welded to a clip (or stab) which engages the 480 volt bus.
Visual inspection disclosed that some of the spot welds did l
not include all of the strands of wire in the connector.
Any loose l
strands would not be available to carry current.
i Analysis of Safety Implications Depending on the number of loose strands and the amount of l
current in the wire, the circuit problems could vary from no problems to moderate overheating or burning off the wire, with the possible failure of the circuit to carry any load.
These breakers supply load to motor-operated valves, small motors, instrument inverters and other safety related equipment.
A case-by-case analysis would be necessary to determine the actual consequences of individual circuit failures.
8407100468 e407o3 j
PDR ADOCK 05000454 35 5 %
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l J. G. Keppler July 3, 1984 Corrective Action The potentially defective spot welds are all being inspected.
Unacceptable connections will be replaced.
Another report will be submitted by August 3, 1984 to document the results of the inspections cnd the schedule for repairs.
Please address any further questions regarding this matter to this office.
Very truly yours,
%8<[Atc%
T. R.
Tramm Nuclear Licensing Administrator 1m l
cc:
Director of Inspection and Enforcement l
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8927N
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