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ACCESSION #: 9705210401 NSD-NRC-97-5093 Westinghouse Energy Systems Nuclear Services Division Electric Corporation Box 355 Pittsburgh, Pennsylvania 15230- 0355 May 14, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Attention: NRC Operations Center Subject: Notification of the Potential Existence of Defects Pursuant to 10CFR21.21 Westinghouse has identified defects that could create a substantial safety hazard should the defect remain uncorrected. Background/Evaluation Deviations were identified by Westinghouse during a lessons learned review of a pilot program to provide safety-related circuit breaker refurbishment for the Byron/Braidwood Nuclear Station sites. The refurbishment pilot program included both Westinghouse Type DHP Series and DS Series breakers. The pilot program was conducted at Westinghouse satellite facilities and failed to utilize correct procedures which resulted in certain tests and inspections not being performed or documented. The items which were omitted or not documented included the performance of timing tests, contact resistance checks to correct values, reapplication of lubricant, opening force margin verification, and weld inspections. These tests and inspections are designed to provide assurance that breaker operation, either to open or close, will be successfully completed. W determined that the tests that were performed on the refurbished breakers before their return to Byron/Braidwood were insufficient to reestablish full qualification of the breakers. Safety Significance The DHP and DS circuit breakers are used in applications such as SI pumps, RHR pumps, fan coolers and vent fans. Although unlikely, installation of breakers that are not fully qualified in redundant trains could result in the inability to perform a safety function on demand. Since the Westinghouse data from the pilot program was considered insufficient, the utility was contacted to collect the operational history of each breaker after refurbishment to provide reasonable assurance of operability. Based on the utility provided data and the fact that the breakers were refurbished at Westinghouse's facilities under controlled conditions by competent personnel, it was determined that the breakers would be operable in the short term. Additional cycling was performed on some refurbished breakers to provide confidence that the breakers would remain operable until proper refurbishment could he completed. "The mission of NSD is to provide our customers with people, equipment and services that set the standards of excellence in the nuclear industry" 2418C-RBM-1:051297 NSD-NRC-97-5093 2 May 14, 1997 The only plants involved in the pilot program were Byron and Braidwood Nuclear Stations. The population of affected applications is limited to twelve DHP and twelve DS breakers which were returned to the Braidwood site and two DS breakers which were returned to the Byron site. Recommendations/Corrective Action All of the breakers that were refurbished using incorrect procedures have been identified. Personnel from each applicable plant have been notified and have confirmed operability of the breakers. As corrective actions, approved Procedures at Westinghouse's satellite facilities have been developed for the continued refurbishment of both DHP and DS breakers to preclude the reoccurrence of this situation. Plans to complete the proper refurbishment of all of the returned breakers are being established. If you have any questions regarding the notifications, please call me at (412) 374-5282. Very truly yours, H. A. Sepp, Manager Regulatory and Licensing Engineering /p 2418C-RBM-2:051297 *** END OF DOCUMENT ***