United States Nuclear Regulatory Commission - Protecting People and the Environment


LICENSEE: ILLINOIS POWER CO.                 

SITE: CLINTON 1                             EN NUMBER:34294

DOCKET: 05000461                         EVENT DATE: 05-28-98

RX TYPE: BWR                             EVENT TIME: 10:00

VENDORS: GE-6                           NOTIFY DATE: 05-28-98

EMERGENCY CLASS: N/A  REGION: 3 STATE: IL      TIME: 12:15

OPS OFFICER: FANGIE JONES             

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       N      0   COLD SHUTDOWN      0   COLD SHUTDOWN  



10 CFR PART 21 FINAL REPORT REGARDING WESTINGHOUSE MODEL DHP     

CIRCUIT BREAKER AUXILIARY SWITCH OPERATING ASSEMBLY ANOMALIES    

                                                                 

ON JANUARY 16, 1998, ILLINOIS POWER (IP) ISSUED 10CFR21 INTERIM  

REPORT 21-97-055 IN LETTER U-602910.  THIS NOTIFIED THE NRC THAT 

AN EVALUATION UNDER THE PROVISIONS OF PART 21 OF 10CFR WAS NOT   

COMPLETE FOR ANOMALIES IN SAFETY-RELATED WESTINGHOUSE MODEL DHP  

CIRCUIT BREAKER AUXILIARY SWITCH OPERATING ASSEMBLIES.  IP       

PROVIDED AN UPDATE IN LETTER U-602968 ON MARCH 24, 1998 TO THE   

NRC.  IP HAS COMPLETED THE EVALUATION OF THIS ISSUE AND CONCLUDES

THAT IT SHOULD BE REPORTED UNDER THE PROVISIONS OF 10CFR21.  THE 

BASIS FOR THIS CONCLUSION IS THAT THE ANOMALIES COULD CAUSE A    

FAILURE OF THE AUXILIARY SWITCH OPERATING ASSEMBLY DURING BREAKER

OPERATION, RESULTING IN LOSS OF THE BREAKER SAFETY FUNCTION.     

                                                                 

THE ANOMALIES INCLUDED FOUR CASES OF BENT AUXILIARY SWITCH LINK  

AND TWO CASES OF MISSING "E" CLIPS.  THE BASIC COMPONENT INVOLVED

IN THIS CONDITION IS THE AUXILIARY SWITCH OPERATING ASSEMBLY,    

INCLUDING THE AUXILIARY SWITCHES, THE OPERATING LINK, AND THE    

OPERATING CAM (IF APPLICABLE), FOR WESTINGHOUSE MODEL DHP        

4160-VOLT AND 6900-VOLT CIRCUIT BREAKERS.  THE ASSEMBLY WAS      

SUPPLIED BY WESTINGHOUSE, PITTSBURGH, PA, AS PART OF MODEL DHP   

CIRCUIT BREAKERS.                                                

                                                                 

CLINTON POWER STATION HAS 43 DHP BREAKERS INSTALLED IN           

SAFETY-RELATED APPLICATIONS AND 2 SPARE SAFETY-RELATED DHP       

BREAKERS POTENTIALLY AFFECTED BY THE AUXILIARY SWITCH OPERATING  

ASSEMBLY DEFICIENCIES.  DHP CIRCUIT BREAKERS WILL BE INSPECTED   

AND REWORKED/REFURBISHED AS NECESSARY PRIOR TO STARTUP FROM THE  

CURRENT OUTAGE.                                                  



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