United States Nuclear Regulatory Commission - Protecting People and the Environment


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.                                                     


Page Last Reviewed/Updated Thursday, March 29, 2012