United States Nuclear Regulatory Commission - Protecting People and the Environment


LICENSEE: ROCHESTER GAS & ELECTRIC CORP.     

SITE: GINNA 1                               EN NUMBER:34632

DOCKET: 05000244                         EVENT DATE: 07-27-98

RX TYPE: PWR                             EVENT TIME: 12:00

VENDORS: W-2-LP                         NOTIFY DATE: 08-12-98

EMERGENCY CLASS: N/A  REGION: 1 STATE: NY      TIME: 14:10

OPS OFFICER: DICK JOLLIFFE            

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



10CFR21 - WESTINGHOUSE DB-75 CIRCUIT BREAKERS WITH MISSING       

TRIPPER BAR TABS                                                 

THERE ARE SIX WESTINGHOUSE DB-75 CIRCUIT BREAKERS INSTALLED AT   

GINNA IN SAFEGUARDS BUSES #14 AND #16 AND ONE UNINSTALLED SAFETY 

RELATED SPARE.                                                   

                                                                 

ON 03/25/98, DURING TROUBLESHOOTING ACTIVITIES, THE LICENSEE     

DISCOVERED THAT THE CENTER TRIPPER BAR TABS WERE MISSING FROM A  

WESTINGHOUSE DB-75 CIRCUIT BREAKER INSTALLED IN THE 'B' EMERGENCY

DIESEL GENERATOR (EDG) SUPPLY CIRCUIT BREAKER TO THE CLASS 1E    

SAFETY RELATED BUS #16 AT GINNA.                                 

                                                                 

PRIOR TO 03/25/98, GINNA MAINTENANCE TECHNICIANS HAD RETROFIT THE

'B' EDG DB-75 SUPPLY CIRCUIT BREAKER WITH AN AMPTECTOR SOLID     

STATE TRIP UNIT PER WESTINGHOUSE INSTRUCTION I.B. 33-850-6 THAT  

INSTRUCTED THE TECHNICIANS TO REMOVE ALL TRIPPER BAR TABS FROM   

THE TRIPPER BAR. SUBSEQUENTLY, THE WESTINGHOUSE INSTRUCTION      

BULLETIN WAS REVISED TO SPECIFICALLY LEAVE THE CENTER TRIPPER BAR

TAB INSTALLED.  THERE WERE NO WESTINGHOUSE NOTIFICATIONS TO GINNA

TO REINSTALL THE CENTER TRIPPER BAR TABS ON PREVIOUSLY MODIFIED  

DB-75 CIRCUIT BREAKERS.                                          

                                                                 

THE ABSENCE OF THE CENTER TRIPPER BAR TAB ALLOWED TWO TRIPPER BAR

BUSHINGS TO FALL FROM THEIR HOUSING AND IS BELIEVED, OVER TIME,  

TO HAVE BENT THE TRIPPER BAR SO THAT IT WOULD NOT FULLY RESET.   

THE FAILURE OF THE TRIPPER BAR TO FULLY RESET CAUSED THE         

INTERMITTENT FAILURE TO CLOSE ON THE DB-75 'B' EDG SUPPLY CIRCUIT

BREAKER TO BUS #16.                                              

                                                                 

WITH THE IDENTIFIED DEFICIENCY IN THE 'B' EDG SUPPLY CIRCUIT     

BREAKER, IT IS POSSIBLE THAT A SINGLE FAILURE COULD RENDER BOTH  

SAFETY TRAINS INCAPABLE OF PERFORMING THEIR SAFETY FUNCTIONS     

(BUSES #14 AND #16).  THIS DEFICIENCY CONSTITUTES A SUBSTANTIAL  

SAFETY HAZARD.                                                   

                                                                 

BETWEEN MAR 85 AND FEB 88, THE DB-75 'B' EDG SUPPLY CIRCUIT      

BREAKER WAS INSTALLED WITH THE INCORRECT MODIFICATION.  IN FEB   

88, THE DB-75 CIRCUIT BREAKER INSTALLED IN THE 'A' EDG SUPPLY    

BREAKER ON BUS #14 WAS INCORRECTLY MODIFIED IN THE SAME MANNER AS

THE 'B' EDG SUPPLY CIRCUIT BREAKER. BETWEEN FEB 88 AND MAY 96,   

BOTH EDG OUTPUT CIRCUIT BREAKERS TO BUSES #14 AND #16 WERE       

INSTALLED WITH THE INCORRECT MODIFICATIONS.                      

                                                                 

IN MAY 96, THE ORIGINAL SPARE DB-75 CIRCUIT BREAKER, #96-04, WAS 

INSTALLED IN THE 'A' EDG SUPPLY BREAKER POSITION.  CIRCUIT       

BREAKER #96-04 HAD BEEN MODIFIED CORRECTLY PER THE CURRENT       

REVISION OF THE WESTINGHOUSE INSTALLATION INSTRUCTIONS PRIOR TO  

BEING INSTALLED INTO THE 'A' EDG                                 

SUPPLY CIRCUIT BREAKER POSITION.                                 

                                                                 

ON 03/25/98, THE LICENSEE INSPECTED ALL WESTINGHOUSE DB-75       

CIRCUIT BREAKERS AT GINNA.  PLANT MAINTENANCE TECHNICIANS        

INSTALLED CENTER TRIPPER BAR TABS ON THE 'B' EDG SUPPLY CIRCUIT  

BREAKER AND THE SPARE CIRCUIT BREAKER, PREVIOUSLY INSTALLED IN   

THE 'A' EDG SUPPLY CIRCUIT BREAKER POSITION.                     

THE DB-75 CIRCUIT BREAKERS ON BUSES #14 AND #16 AND THE TWO BUS  

TIE CIRCUIT BREAKERS BETWEEN BUSES #14 AND #16 HAD BEEN CORRECTLY

MODIFIED PER THE REVISED WESTINGHOUSE INSTRUCTIONS.              

                                                                 

ALTHOUGH THE POTENTIAL FOR FAILURE EXISTED AT GINNA, THE         

WESTINGHOUSE DB-75 CIRCUIT BREAKERS WERE TESTED WITH REGULAR     

SURVEILLANCE TESTS TO PROVE OPERABILITY AND THE FAILURE MECHANISM

IS OF THE NATURE THAT DEGRADES OVER TIME.  THE MISSING TRIPPER   

BAR TAB WOULD NOT IMMEDIATELY FAIL THE CIRCUIT BREAKER UPON      

REMOVAL.                                                         

                                                                 

LICENSEE NUCLEAR ENGINEERING PERSONNEL ARE PERFORMING A VENDOR   

DOCUMENT REVIEW TO VERIFY THAT ALL WESTINGHOUSE DB-75 CIRCUIT    

BREAKERS ARE PROPERLY CONFIGURED IN ACCORDANCE WITH APPLICABLE   

VENDOR DOCUMENTATION. ALL LICENSEE CORRECTIVE ACTIONS ARE        

SCHEDULED TO BE COMPLETED BY 12/31/98.                           

                                                                 

ON 03/25/98, THE LICENSEE DISTRIBUTED A NOTIFICATION OF THIS     

CONDITION TO INDUSTRY REPRESENTATIVES.  THE CENTER TRIPPER BAR   

TAB INSTALLATION CAN BE VERIFIED BY VISUAL INSPECTION, POSSIBLY  

WHILE THE CIRCUIT BREAKER IS IN SERVICE.                         

                                                                 

SPECIFIC INFORMATION FOR THIS REPORT WAS OBTAINED DURING         

DISCUSSIONS WITH WESTINGHOUSE REPRESENTATIVES ON 07/27/98.       

                                                                 

THE LICENSEE PLANS TO SUBMIT A WRITTEN 10CFR21 REPORT OF THIS    

CONDITION TO THE NRC BY 09/11/98.                                



Page Last Reviewed/Updated Thursday, March 29, 2012