United States Nuclear Regulatory Commission - Protecting People and the Environment


LICENSEE: COMMONWEALTH EDISON CO.            

SITE: BRAIDWOOD 1 2                         EN NUMBER:29906

DOCKET: 05000456 05000457                EVENT DATE: 01-30-96

RX TYPE: PWR PWR                         EVENT TIME: 00:00

VENDORS: W-4-LP W-4-LP                  NOTIFY DATE: 01-30-96

EMERGENCY CLASS: N/A  REGION: 3 STATE: IL      TIME: 14:48

OPS OFFICER: RUDY KARSCH              

10 CFR SECTION: CDEG  21.21(c)(3)(i)      DEFECTS/NONCOMPLIANCE

UNIT  SCRAM   RX   INIT  INITIAL MODE     CURR   CURRENT MODE

      CODE   CRIT  PWR                    PWR

 1    N       Y    100   POWER OPERATION  100   POWER OPERATION

 2    N       Y    100   POWER OPERATION  100   POWER OPERATION



THE LICENSEE REPORTED SOLDERING DEFECTS IN RELAYS USED IN        

EMERGENCY DIESEL GENERATORS (EDGs) AT BYRON AND BRAIDWOOD        

STATIONS.                                                        

                                                                 

RELAYS MANUFACTURED BY THE AMERACE CORPORATION HAVE A

COMMERCIAL 

GRADE ADD-ON BOARD WITH COMPONENTS TO SUPPRESS A COIL            

DEENERGIZATION TRANSIENT. THE LICENSEE DISCOVERED THAT THE SOLDER

CONNECTION BETWEEN THE RELAY AND THIS ADD-ON BOARD IS DEFECTIVE. 

THE FAILURE OF THIS RELAY COULD CAUSE THE EDG TO FAIL TO START.  

THE LICENSEE HAS REPAIRED THE DEFECTIVE SOLDER JOINTS AND        

REINSTALLED THE RELAYS.  DEFECTIVE RELAYS COULD BE INSTALLED AT  

OTHER NUCLEAR PLANTS.                                            



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