Part 21 Report - 1995-003
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.
Page Last Reviewed/Updated Wednesday, March 24, 2021