United States Nuclear Regulatory Commission - Protecting People and the Environment

LICENSEE: WESTINGHOUSE ELECTRIC CORPORATION  
SITE: WESTINGHOUSE ELECTRIC CORPORAT        EN NUMBER:31449
DOCKET:                                  EVENT DATE: 12-13-96
RX TYPE:                                 EVENT TIME: 00:00
VENDORS:                                NOTIFY DATE: 12-13-96
EMERGENCY CLASS: N/A  REGION: 1 STATE: PA      TIME: 14:22
OPS OFFICER: LEIGH TROCINE            
10 CFR SECTION: CCCC  21.21               UNSPECIFIED PARAGRAPH

MOLDED CASE CIRCUIT BREAKERS WITH INCORRECTLY INSTALLED DC SHUNT 
TRIP UNITS AND MISSING SHUNT TRIP BARRIERS                       
                                                                 
CALLAWAY IDENTIFIED A DEVIATION DURING TESTING OF 6 TYPE HFD3045 
AND HFD3060 MOLDED CASE CIRCUIT BREAKERS WITH 125-VOLT DC SHUNT  
TRIP DEVICES SUPPLIED AS SAFETY-RELATED BY WESTINGHOUSE.  THE    
SHUNT TRIP CIRCUITRY IS SPECIFIED TO BE EQUIPPED WITH A CUT-OFF  
SWITCH TO REMOVE THE SHUNT TRIP COIL FROM THE POWER SOURCE       
SUBSEQUENT TO TRIPPING THE BREAKER.  THE COIL IS NOT DESIGNED FOR
CONTINUOUS DUTY AND WOULD EVENTUALLY OPEN THE CIRCUIT IF IT      
REMAINED ENERGIZED.  THE SHUNT TRIP COIL OF THE BREAKERS SUPPLIED
TO CALLAWAY REMAINED CONNECTED TO THE POWER SOURCE AFTER THE     
BREAKER TRIPPED. IN ADDITION, DURING THE EVALUATION OF THE       
BREAKERS THAT WERE RETURNED FROM CALLAWAY, IT WAS DETERMINED
THAT
SHUNT TRIP BARRIERS WERE MISSING.  THESE BARRIERS PROVIDE        
PROTECTION AGAINST DAMAGE DUE TO ARCING.  THE VENDOR (CUTLER     
HAMMER) DETERMINED THAT 21 BREAKERS WITH EITHER AC OR DC SHUNT   
TRIP UNITS (INCLUDING THE 6 REFERENCED ABOVE) HAD BEEN SHIPPED   
ONLY TO THE CALLAWAY PLANT.  SUBSEQUENT OPERABILITY OF THESE     
BREAKERS AFTER A TRIP HAS NOT YET BEEN DETERMINED BY CUTLER      
HAMMER.                                                          
                                                                 
ALL SIX OF THE BREAKERS WITH INCORRECTLY INSTALLED DC SHUNT TRIP 
UNITS HAVE BEEN IDENTIFIED AND ARE IN THE PROCESS OF BEING       
RETURNED TO THE VENDOR. WESTINGHOUSE HAS ALSO BEEN INFORMED BY   
CALLAWAY THAT ONLY ONE BREAKER WITH A SUSPECT BARRIER IS IN      
SERVICE.  CALLAWAY DOES NOT PLAN TO PLACE THE REMAINING FOURTEEN 
BREAKERS IN SERVICE UNTIL IT IS VERIFIED THAT THE SHUNT TRIP     
BARRIERS ARE INSTALLED.  SINCE SUBSEQUENT OPERABILITY OF THE     
SHUNT TRIP UNITS WITH MISSING BARRIERS IS INDETERMINATE, CALLAWAY
WILL BE ADVISED TO PERFORM A SURVEILLANCE TEST AFTER ANY BREAKER 
TRIP DEMAND UNTIL THE BREAKER CAN BE CORRECTED OR REPLACED.      

Page Last Reviewed/Updated Thursday, March 29, 2012