Part 21 Report - 1998-020

LICENSEE: ROCHESTER GAS & ELECTRIC CORP SITE: GINNA EN NUMBER:33442 DOCKET: EVENT DATE: 11-14-97 RX TYPE: EVENT TIME: 12:00 VENDORS: NOTIFY DATE: 12-22-97 EMERGENCY CLASS: N/A REGION: 1 STATE: NY TIME: 09:10 OPS OFFICER: DOUG WEAVER 10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH PART 21 - DEFECTIVE SHUNT TRIP COILS THE LICENSEE DISCOVERED A WESTINGHOUSE DB-75 BREAKER THAT WAS FAILING TO CLOSE AT THEIR GINNA PLANT. THE PLUNGER OF THE SHUNT TRIP COIL ASSEMBLY WAS BINDING, MAINTAINING THE BREAKER TRIPPER BAR IN THE TRIP FREE POSITION. THE LICENSEE HAS SEVEN DB-75 BREAKERS ON SITE, ONLY ONE HAD THE PROBLEM DESCRIBED. THE BREAKER WITH THE FAILED SHUNT TRIP COIL IS THE ONLY ONE TO HAVE HAD THAT PART PREVIOUSLY REPLACED. THE REPLACEMENT SHUNT TRIP COIL THAT FAILED WAS ONE OF TEN PURCHASED IN 1977 AS SPARES. THE FAILED SHUNT TRIP COIL WAS REPLACED WITH A SPARE FROM STOCK. THE REMAINING EIGHT ASSEMBLIES IN STOCK WERE INSPECTED. TWO ASSEMBLIES HAD COIL PLUNGERS THAT DID NOT FULLY RETURN TO THE DEENERGIZED POSITION DURING MANUAL MANIPULATION. THESE WERE REMOVED FROM STOCK. LICENSEE RECOMMENDS RECEIPT INSPECTION TO VERIFY ACCEPTABLE PLUNGER MOVEMENT AND ALSO VERIFYING THAT THE SHUNT TRIP COIL PLUNGER MOVES FREELY IN THE COIL ASSEMBLY DURING BREAKER MAINTENANCE.

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