ML20073R146
| ML20073R146 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 05/28/1991 |
| From: | Checca A COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 9106050348 | |
| Download: ML20073R146 (2) | |
Text
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May 28,1991 C
Mr. A. Bert Davis Regional Administrator U.S. Nuclear Regulatory Commission 799 Roosevelt Road Rill Glen Ellyn,11 60137
Subject:
Byron Station Units 1 & 2 High Voltage Switching Training for Equiament Operators Rocke1Moa50-45LacIL455
Reference:
(a) Loss of Offsite Power Event Meeting Held October 21,1987 (b) NRC inspection Report 50-454/87039 issued November 19,1987 (c) Licensee Event Report (LER) 455 87-019
Dear Mr. Davis:
On October 2,1987, Byron Station had a Loss of Offsite Power (LOOP) on Unit 2 that was caused by an operator inadvertently opening the system auxiliary transformer (SAT) disconnects. NRC Inspection Report 50/454/87039 (ref, b) provides details on this event. On October 21,1987, a meeting was held at Region ill (ref, a) to discuss the LOOP event. Byron Station committed and implemented a series of corrective actions to prevent recurrence of this type of event. These actions included:
Disciplinary action was taken with the individual involved.
Switchyard operations would only be performed with a second individual present.
Permanent labels, that were more descriptive, were placed on the Main Power Transformer (MPT) and System Auxiliary Transformer (SAT) disconnects in the switchyard.
A walk through of the switchyard was conducted with the Division Superintendent of Power Supply to demonstrate proper operations and communications.
The SAT disconnects have been locked with unique locks for each unit.
A checklist has been developed that formalizes checks to be made prior to disconnect operation.
Annual high voltage switching requalification was modified to include actual switching operation.
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2-May 28,1991 i
Mr. A. Bert Davis i
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These corrective actions have been effective in preventing similar events at Byron l
Station.
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It has been determined that the commitment to perform actual switching j
operations for training may be adding unnecessary risk to the system grid. The current practice is to perform actual live switching operations in the 345 KV switchyard for initial and requalification training of equipment operators. Presently the live switching i
operations occur one time per year for initial training and a minimum of six times for requalification training. In order to reduce the potential risk to the system grid Byron Station is modifying its commitment. Beginning in June,1991, the requalification-classes will have simulated switching operations in the 345 KV switchyard. This will provide the necessary training for switching operations and will reduce the risk to the system. Byron Station will maintain the actual live switching operations for the initial training classes.
1 Please address any questions regarding this item to this office.
Sincerely, t
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Allen R. Checca Nuclear Licensing Administrator 4
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A.H. Hsia, Project Manager - NRR t
W. Kropp, Resident inspector - Byron
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