Part 21 Report - 2001-020

EVENT TEXT

PART 21 REPORT CONCERNING POSSIBLE INOPERABILITY OF A SAFETY RELATED STATIC INVERTER

On December 14, 2000, Entergy determined that a potential defect existed in the Indian Point 3 safety related 34 static inverter supplied by Westinghouse. Six (6) aluminum electrolytic capacitors manufactured by Mallory Inc. (part number CGS432T200X4C) were purchased from Westinghouse (part number 454A8391110) as commercial grade components. The capacitors were identified as replacement parts in the Westinghouse instruction manual for the 34 static inverter. The capacitors were subsequently dedicated for use in the Indian Point 3 safety related static inverter 34. The dedication program did not identify a mounting restriction since this is not typically a critical characteristic for replacement parts. The Westinghouse instruction manual, used for procurement, did not specify any restriction on mounting orientation. Indian Point 3 (IP3) considers this a deviation. IP3 was notified, by Westinghouse letter dated September 5, 2000, that an internal design change to the capacitor had been made by Mallory that imposed the mounting restriction. Mounting of the capacitors in a horizontal direction could result in catastrophic failure of the component (i.e., short circuit) and render the 34 static inverter and associated instrument bus inoperable. IP3 considers this a potential substantial safety hazard because IP3 is not designed for a postulated design basis accident with a single failure (e.g., failure of another inverter) and the failure of the 34 static inverter. On October 26, 2000 the plant was shutdown and corrective action was completed to replace the inverter capacitors prior to their failure. An operating experience event report is being prepared for distribution to the industry. Westinghouse has discontinued use of this model Mallory capacitor. The Indian Point 3 staff has not ascertained other potential users or uses of the capacitors." The licensee notified the NRC Resident Inspector.