United States Nuclear Regulatory Commission - Protecting People and the Environment

SAN ONOFRE 2 3                 29096 07-21-95 POW
LICENSEE: SOUTHERN CALIFORNIA EDISON & SAN DI
SITE: .SAN ONOFRE 2 3                .        EN NUMBER:29096
DOCKET:  05000361 05000362               EVENT DATE: 07-21-95
RX TYPE:  PWR PWR                        EVENT TIME: 00:00
VENDORS:  CE CE                         NOTIFY DATE: 07-21-95
EMERGENCY CLASS: N/A  REGION: 4 STATE: CA      TIME: 20:45
OPS OFFICER: TIM McGINTY              
10 CFR SECTION: CCCC  21.21               UNSPECIFIED PARAGRAPH
UNIT  SCRAM   RX   INIT  INITIAL MODE     CURR   CURRENT MODE
      CODE   CRIT  PWR                    PWR
 2    N       Y    100   POWER OPERATION  100   POWER OPERATION
 3    N       Y     83   POWER OPERATION   83   POWER OPERATION

SAN ONOFRE PROVIDED A PART 21 REPORT REGARDING POTTER & BRUMFIELD
(P&B) MODEL-5095 MOTOR-DRIVEN RELAYS (MDR).  SAN ONOFRE WAS      
NOTIFIED BY P&B OF POSSIBLE IMPROPER RE-ASSEMBLY OF SEVERAL      
DIFFERENT MODELS OF P&B RELAYS. THE IMPROPER RE-ASSEMBLY INVOLVES
INTERNALLY DAMAGED (BENT) CONTACT ARMS THAT COULD ADVERSELY      
EFFECT RELAY INTERRUPT CAPABILITY, DIELECTRIC CAPABILITY,        
RELIABILITY, AND LIFE EXPECTANCY.  THE PROBLEM IS POTENTIALLY    
APPLICABLE TO ANY MDR RELAY RETURNED TO P&B FOR REWORK OR        
DISASSEMBLY BETWEEN MARCH 1993 AND MARCH 1995.                   
                                                                 
POTTER & BRUMFIELD INC. (A SEIMENS CO.) IS LOCATED IN MARION, KY.
 SEVEN OF EIGHTEEN RELAYS RETURNED FROM P&B TO SONGS WERE        
SUBSEQUENTLY INSTALLED IN SAFETY-RELATED SYSTEMS OF THE SONGS    
PLANTS.  THE MOST LIMITING APPLICATION OF THESE SEVEN MDR RELAYS 
IS IN THE CONTROL CIRCUITS OF VALCOR SOLENOID VALVES WHICH       
ISOLATE CONTAINMENT PRESSURE TRANSMITTER SENSING LINES AT UNITS 2
AND 3.  THE SOLENOID VALVES ARE NORMALLY OPEN AND REMAIN OPEN    
DURING ACCIDENT CONDITIONS INSIDE THE CONTAINMENT.  THESE VALVES 
ARE ONLY REQUIRED TO CLOSE IN ORDER TO ISOLATE A SENSING LINE    
FAILURE OR LOSS OF PRESSURE BOUNDARY IN THE TRANSMITTER.  THE    
SEVEN INSTALLED RELAYS WILL BE REPLACED AT THE EARLIEST          
OPPORTUNITY FOLLOWING PROCUREMENT OF REPLACEMENTS. THE SEVEN     
INSTALLED P&B MDR RELAYS AT SONGS REMAIN OPERABLE AT THIS TIME   
BASED ON POSITIVE DEDICATION TESTING RESPONSE, SYSTEM DESIGN USE,
SUCCESSFUL INSTALLATION POST-MAINTENANCE TESTING, AND PAST       
OPERATING EXPERIENCE WITH OTHER RELAYS USED IN THIS TYPE         
APPLICATION.                                                     
                                                                 
THE HOO FORWARDED THE PART 21 NOTIFICATION TO VERN HODGE.        

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