Part 21 Report - 1998-590
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 Wednesday, March 24, 2021