United States Nuclear Regulatory Commission - Protecting People and the Environment

SEQUOYAH 1 2                   28206 01-03-95 POW
LICENSEE: TENNESSEE VALLEY AUTHORITY         
SITE: SEQUOYAH 1 2                          EN NUMBER:28206
DOCKET: 05000327 05000328                EVENT DATE: 01-03-95
RX TYPE: PWR PWR                         EVENT TIME: 04:21
VENDORS: W-4-LP W-4-LP                  NOTIFY DATE: 01-03-95
EMERGENCY CLASS: UNU  REGION: 2 STATE: TN      TIME: 05:15
OPS OFFICER: JOHN MacKINNON           
10 CFR SECTION: AUNA  50.72(b)(1)(ii)(A)  UNANALYZED COND OP   
                AAEC  50.72(a)(1)(i)      EMERGENCY DECLARED   
                NLCO                      TECH SPEC LCO A/S    
UNIT  SCRAM   RX   INIT  INITIAL MODE     CURR   CURRENT MODE
      CODE   CRIT  PWR                    PWR
 1    N       Y    100   POWER OPERATION  100   POWER OPERATION
 2    N       Y    100   POWER OPERATION  100   POWER OPERATION

LATCHES (TWO LATCHES ONE IN UPPER RIGHT HAND SIDE OF THE CUBICLE 
AND THE OTHER LATCH IN THE UPPER LEFT HAND SIDE OF THE CUBICLE)  
WHICH HOLDS BREAKER IN ITS COMPARTMENT FOUND TO BE UNLATCHED.    
                                                                 
WHILE PERFORMING CONTROL BOARD WALKDOWN FOR UNIT 2 THE ONCOMING  
SENIOR REACTOR OPERATOR (SRO) DISCOVERED THAT 2-FCV-63-8, A      
SAFETY RELATED VALVE (USED TO SUPPLY SUCTION FROM CONTAINMENT    
SUMP TO HIGH & INTERMEDIATE HEAD SAFETY INJECTION PUMPS AFTER    
REFUELING WATER STORAGE TANK LEVEL GETS LOW), HAD NO INDICATION  
OF VALVE POSITION. THE UNIT OPERATOR REPLACED THE LIGHT BULB AND 
THE 480V BREAKER WAS VERIFIED CLOSED, BUT THERE WAS STILL NO     
INDICATION OF THE VALVE POSITION. A SRO WAS DISPATCHED TO THE    
BREAKER. THE SRO VERIFIED THE FUSES WERE GOOD. WHILE CHECKING THE
FUSES THE BREAKER IN ITS COMPARTMENT BEGAN TO MOVE AND THE SRO   
NOTICED THE LOCAL INDICATING LIGHT FOR THE BREAKER FLICKERED. THE
SRO PUSHED THE BREAKER SNUGLY INTO ITS COMPARTMENT UNTIL IT WAS  
FULLY LATCHED AND VERIFIED BREAKER HAD PROPER INDICATION. THE    
VALVE, INDICATED CLOSED AT THE BREAKER COMPARTMENT AND REMOTELY  
IN THE MAIN CONTROL ROOM. IT WAS SUBSEQUENTLY DETERMINED THAT    
THIS VALVE WOULD NOT HAVE OPERATED AND THE ACTIONS OF LCO 3.5.2  
WAS ENTERED AND EXITED DUE TO "A" TRAIN OF ECCS BEING INOPERABLE.
A COMPLETE CONTROL BOARD WALKDOWN WAS PERFORMED AND NO OTHER     
SAFETY RELATED VALVES WERE FOUND WITHOUT POSITION INDICATION.    
FURTHER INVESTIGATION OF WHY THE BREAKER WAS NOT FULLY ENGAGED   
REVEALED THE "COMPARTMENT RETENTION LATCH - TWO FOR EACH BREAKER"
WAS NOT FULLY ENGAGED. THE SHIFT OPERATING SUPERVISOR DIRECTED   
ALL 480V MOLDED CASE BREAKERS TO BE CHECKED FOR SIMILAR          
CONDITION. NUMEROUS BREAKERS WERE FOUND TO BE IN AN UNLATCHED OR 
PARTIALLY UNLATCHED (ONE OF THE TWO LATCHES UNLATCHED) CONDITION,
AND THESE BREAKERS WERE CORRECTED ON THE SPOT DUE TO THE         
POTENTIAL FOR THESE BREAKERS TO BE IN AN UNLATCHED CONDITION AND 
BECOME DISENGAGED, AND THE POSSIBILITY OF BOTH TRAINS OF THE ESF 
EQUIPMENT TO BE INOPERABLE AT THE SAME TIME. LICENSEE DETERMINED 
THAT THEY WERE IN AN UNANALYZED CONDITION. LICENSING AND NUCLEAR 
ENGINEERING WERE CONSULTED OF THIS CONDITION. LICENSEE SAID THAT 
THEY STILL CHECKING BREAKERS AT THIS TIME FOR UNIT 1 AND UNIT 2. 
                                                                 
   ****UPDATE 0538EST 01/03/95 BY BILL HARRIS TAKEN BY           
MACKINNON****                                                    
                                                                 
LICENSEE UPGRADED THIS EVENT TO AN UNUSUAL EVENT CLASSIFICATION  
PER THEIR RADIOLOGICAL EMERGENCY PLANS "HU15" (CONDITIONS THAT   
WARRANT INCREASED AWARENESS OF PLANT OPERATING STAFF). LICENSEE  
CONSIDERS THIS A SEISMIC CONCERN TO THE PLANT IN THAT IF THEY HAD
A SEISMIC EVENT AND THE BREAKERS WERE UNLATCHED THE BREAKERS     
COULD POSSIBLY DISENGAGE FROM THEIR POWER SOURCE AND BECOME      
INOPERABLE. LICENSEE WILL NOTIFY STATE AND LOCAL OFFICIALS OF    
THIS EVENT CLASSIFICATION.                                       
                                                                 
RESIDENT INSPECTOR WAS INFORMED BY THE LICENSEE OF THIS EVENT.   
                                                                 
 * * * UPDATE @ 1002 ON 1/3/95 BY DENNIS DIMOPHULOS TAKEN BY     
WEAVER * * *                                                     
THE UNUSUAL EVENT WAS TERMINATED AT 0959 EST.  A COMPLETE        
WALKDOWN OF THE SAFETY RELATED BOARDS AND NON SAFETY RELATED     
BOARDS IN SEISMIC AREAS WAS COMPLETED.  ALL DISCREPANCIES WERE   
CORRECTED ON THE SPOT, WITH THE EXCEPTION OF ONE CASE WHERE ONE  
OF THE TWO LATCHES WAS BROKEN.  THE CAUSE OF THIS CONDITION IS   
UNDER INVESTIGATION.                                             
                                                                 
THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR.  THE HOO       
INFORMED THE RDO (VIAS); EO (DENNIG); FEMA (SHULL)               
                                                                 
***UPDATE AT17:17 ON 1/20/95 BY DIMOPHULOS TAKEN BY GOULD***     
                                                                 
THE LICENSEE IS RETRACTING THIS EVENT BECAUSE FURTHER EVALUATIONS
HAVE DETERMINED THAT THE BREAKERS WERE OPERABLE BECAUSE THE      
CABINET DOORS WERE ADEQUATE TO RESTRICT BREAKER MOVEMENT DURING
A
SEISMIC EVENT. THEREFORE, THE LICENSEE HAS DETERMINED THAT THIS  
EVENT IS NOT REPORTABLE. THE RI HAS BEEN INFORMED.               

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