United States Nuclear Regulatory Commission - Protecting People and the Environment

CLINTON 1                      29426 10-06-95 POW
LICENSEE: ILLINOIS POWER CO.                 
SITE: .CLINTON 1                     .        EN NUMBER:29426
DOCKET: 05000461                         EVENT DATE: 10-06-95
RX TYPE: BWR                             EVENT TIME: 11:49
VENDORS: GE-6                           NOTIFY DATE: 10-06-95
EMERGENCY CLASS: N/A  REGION: 3 STATE: IL      TIME: 11:49
OPS OFFICER: JOSEPH SEBROSKY          
10 CFR SECTION: CCCC  21.21               UNSPECIFIED PARAGRAPH
UNIT  SCRAM   RX   INIT  INITIAL MODE     CURR   CURRENT MODE
      CODE   CRIT  PWR                    PWR
 1    N       Y    100   POWER OPERATION  100   POWER OPERATION

THE LICENSEE ISSUED A 10 CFR PART 21 REPORT DUE TO A PROBLEM WITH
A SOLID STATE TRIP DEVICE FOR ELECTRICAL BREAKERS.               
                                                                 
ON AUGUST 7, 1995, DURING AN ATTEMPT TO SHIFT THE CONTROL ROOM   
HEATING VENTILATING AND AIR CONDITIONING SYSTEM OPERATION FROM   
THE A-TRAIN TO THE B-TRAIN, THE B-TRAIN RETURN AIR FAN WOULD NOT 
START.  AN INVESTIGATION FOUND THE FAN'S CIRCUIT BREAKER IN A    
TRIPPED CONDITION.  TROUBLESHOOTING LED TO REPLACEMENT OF THE    
BREAKER.  TESTING OF THE DEFICIENT BREAKER IDENTIFIED THAT ITS   
SOLID STATE TRIP DEVICE WAS CAUSING THE BREAKER TO TRIP.         
ILLINOIS POWER OFFICIALS RETURNED THE SOLID STATE TRIP DEVICE TO 
THE MANUFACTURER FOR FURTHER TESTING.                            
                                                                 
ON AUGUST 21, 1995, ILLINOIS POWER IDENTIFIED ANOTHER POTENTIALLY
DEFICIENT SOLID STATE TRIP DEVICE.  THIS DEVICE WAS INSTALLED IN 
THE CIRCUIT BREAKER FOR THE 'B' SWITCHGEAR HEAT REMOVAL SYSTEM   
CONDENSING UNIT MOTOR.                                           
                                                                 
THE BASIC COMPONENTS INVOLVED ARE SOLID STATE TRIP DEVICES, TYPE 
SS-13, MANUFACTURER PART NUMBER 609901-T012.  THE DEVICES WERE   
MANUFACTURED BY GOULD/ITE (NOW ABB, ASEA BROWN BOVERI).  THE     
LICENSEE DOES NOT INDICATE IN THE PART 21 REPORT THE TOTAL NUMBER
OF THIS TYPE OF TRIP DEVICES AT CLINTON OR OTHER NUCLEAR POWER   
PLANTS.  HOWEVER, THE LICENSEE DOES STATE THAT A MODEL SS-13     
SOLID STATE TRIP DEVICE IS TYPICALLY INSTALLED ON AUXILIARY POWER
480-VOLT CIRCUIT BREAKERS USED FOR MOTOR CONTROL AT CLINTON.     

Page Last Reviewed/Updated Thursday, March 29, 2012