U.S. Nuclear Regulatory Commission Operations Center Event Reports For 04/20/95 - 04/21/95 ** EVENT NUMBERS ** 28706 28707 28708 28709 +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28706 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: GRAND GULF REGION: 2 |NOTIFICATION DATE: 04/20/95 | |UNIT: [1] [ ] [ ] STATE: MS |NOTIFICATION TIME: 00:30 [ET]| |RX TYPE: [1] GE-6 |EVENT DATE: 04/19/95 | +------------------------------------------------+EVENT TIME: 21:47[CDT]| |NRC NOTIFIED BY: KELLY McDONALD |LAST UPDATE DATE: 04/20/95 | |HQ OPS OFFICER: LEIGH TROCINE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |CAUDLE JULIAN RDO | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N N 0 REFUELING | 0 REFUELING | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | UNEXPECTED ESF ACTUATION (VENTILATION ISOLATION AND STANDBY GAS TREATMENT | | ACTUATION). | | | | DURING THE PERFORMANCE OF AN ELECTRICAL WORK ORDER, 125-VOLT DC BREAKER NO. | | 72-DA33 WAS OPENED FOR AN OVERCURRENT TRIP TEST. ALTHOUGH THIS THIS ACTION | | WAS PERFORMED PER THE WORK ORDER, IT RESULTED IN THE UNEXPECTED | | DE-ENERGIZATION OF THE CONTROL LOGIC FOR DIVISION 1 STANDBY GAS TREATMENT, | | "A" CONTROL ROOM STANDBY FRESH AIR, AND "A" COMBUSTIBLE GAS CONTROL. THIS | | IN TURN CAUSED THESE SYSTEMS TO AUTOMATICALLY INITIATE. THE DIVISION 1 | | AUXILIARY BUILDING ISOLATION VALVES ALSO RECEIVED AN ISOLATION SIGNAL. | | BREAKER NO. 72-DA33 WAS RECLOSED WITHIN APPROXIMATELY 30 SECONDS, AND | | SYSTEMS WERE RESTORED TO PRE-EVENT STATUS. THE LICENSEE'S ROOT CAUSE | | INVESTIGATION IS ONGOING. | | | | THE NRC RESIDENT INSPECTOR WILL BE NOTIFIED BY THE LICENSEE. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28707 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: ARKANSAS NUCLEAR REGION: 4 |NOTIFICATION DATE: 04/20/95 | |UNIT: [1] [ ] [ ] STATE: AR |NOTIFICATION TIME: 05:53 [ET]| |RX TYPE: [1] B&W-L-LP,[2] CE |EVENT DATE: 04/20/95 | +------------------------------------------------+EVENT TIME: 03:13[CDT]| |NRC NOTIFIED BY: DARYLL SAULSBERRY |LAST UPDATE DATE: 04/20/95 | |HQ OPS OFFICER: LEIGH TROCINE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |CHARLES CAIN RDO | |ARPS 50.72(b)(2)(ii) RPS ACTUATION | | |APRE 50.72(b)(2)(vi) OFFSITE NOTIFICATION | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | A/R Y 100 POWER OPERATION | 0 HOT STANDBY | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AUTOMATIC REACTOR TRIP DUE TO A GENERATOR LOCKOUT WHICH WAS CAUSED BY A | | GENERATOR STATOR GROUND. | | | | A LIGHTNING STRIKE APPARENTLY CAUSED A GENERATOR STATOR GROUND WHICH | | SUBSEQUENTLY CAUSED A GENERATOR LOCKOUT AND REACTOR TRIP. ALL RODS | | INSERTED AS DESIGNED. THERE WAS NO LOSS OF OFFSITE POWER, AND THERE WERE | | NO PROBLEMS WITH ANY POWER SUPPLY TRANSFERS. ALL ECCS SYSTEMS AND EDGS ARE | | CURRENTLY OPERABLE, AND THERE WERE NO ESF ACTUATIONS. THE LICENSEE IS | | STEAMING TO THE MAIN CONDENSER AND FEEDING WITH EFW. THE LICENSEE NEVER | | STEAMED TO ATMOSPHERE. THE UNIT IS CURRENTLY IN A STABLE CONDITION. | | | | THE FOLLOWING ABNORMAL SYSTEM FUNCTIONS OCCURRED POSSIBLY DUE TO THE | | LIGHTNING STRIKE: (1) MAIN STEAM SAFETY VALVE REMAINED OPEN FOR LONGER | | THAN EXPECTED ON THE "B" STEAM GENERATOR (ALL MAIN STEAM SAFETY VALVES ARE | | CURRENTLY CLOSED.), (2) HALF TRIP ON EMERGENCY FEEDWATER INITIATION AND | | CONTROL SYSTEM DUE TO POWER SUPPLY PROBLEM AND WAS CAUSED BY A LOW LEVEL | | INITIATE ON EFW (NO ACTUAL LOW LEVEL CONDITION OCCURRED.), (3) DECREASE OF | | CONDENSER VACUUM TO APPROXIMATELY 20.4" Hg (CONDENSER VACUUM IS RECOVERING | | AT THIS TIME, AND THE ROOT CAUSE IS CURRENTLY UNDER INVESTIGATION.), AND | | (4) ATMOSPHERIC DUMP VALVE NO. CV-2668 ON THE "A" STEAM GENERATOR RECEIVED | | AN OPEN DEMAND SIGNAL BUT THE DOWNSTREAM BLOCK VALVE REMAINED CLOSED (THE | | ROOT CAUSE IS CURRENTLY UNDER INVESTIGATION.). | | | | THE LICENSEE MADE A COURTESY CALL TO THE ARKANSAS DEPARTMENT OF HEALTH AND | | WILL INFORM THE NRC RESIDENT INSPECTOR. NO PRESS RELEASE IS PLANNED. | | | | ***UPDATE 4/20/95 @ 1715 FROM SCHEIDE TAKEN BY SEBROSKY *** | | THE LICENSEE IS UPDATING THIS REPORT TO CLARIFY SOME INFORMATION. STEAM | | PRESSURE WAS MANUALLY REDUCED FORM APPROXIMATELY 1000 PSIA TO 900 PSIA TO | | RESEAT THE 'B' MAIN STEAM SAFETY VALVE. THE HALF TRIP OF THE EFW SYSTEM | | WAS DUE TO A +5-VOLT POWER SUPPLY FAILURE WHICH CAUSED A LOW LEVEL INITIATE | | SIGNAL TO BE GENERATED. NO LOW LEVEL CONDITION ACTUALLY EXISTED IN EITHER | | STEAM GENERATOR, AND NO EFW ACTUATION OCCURRED. THE POWER SUPPLY FAILED | | APPROXIMATELY ONE HOUR AFTER THE UNIT TRIPPED. | | | | THE FAILURE OF THIS SAME POWER SUPPLY PRECLUDED REMOTE OPERATION OF THE | | ATMOSPHERIC DUMP VALVE (ADV) ON THE 'A' STEAM GENERATOR. THE VALVE DID | | RESPOND TO LOCAL MANUAL OPERATION. NO STEAM RELEASE OCCURRED FROM THE ADV | | OPERATION. | | | | THE GENERATOR LOCKOUT WAS FROM A GENERATOR NEGATIVE PHASE SEQUENCE RELAY | | TRIP. THE LICENSEE IS UNSURE IF LIGHTNING WAS THE ROOT CAUSE OF THIS | | PROBLEM AND IS CONTINUING TO INVESTIGATE. | | | | THE LICENSEE HAS INFORMED THE RESIDENT INSPECTOR AND STATE OFFICIALS OF | | THIS UPDATE. HOO NOTIFIED R4DO (CAIN). | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28708 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: VERMONT YANKEE REGION: 1 |NOTIFICATION DATE: 04/20/95 | |UNIT: [1] [ ] [ ] STATE: VT |NOTIFICATION TIME: 09:13 [ET]| |RX TYPE: [1] GE-4 |EVENT DATE: 04/20/95 | +------------------------------------------------+EVENT TIME: 07:28[EDT]| |NRC NOTIFIED BY: KRITZER |LAST UPDATE DATE: 04/20/95 | |HQ OPS OFFICER: CHAUNCEY GOULD +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |WILLIAM RULAND RDO | |ARPS 50.72(b)(2)(ii) RPS ACTUATION | | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | A N 0 COLD SHUTDOWN | 0 COLD SHUTDOWN | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE LICENSEE REPORTED THE OCCURRENCE OF AN RPS M/G SET TRIP WHILE IN COLD | | SHUTDOWN. | | | | THE PLANT HAD A TRIP OF THE "B" RPS M/G SET ALONG WITH A GROUP 3 PCIS | | ISOLATION. THERE WAS NO ROD MOTION BECAUSE THE RODS WERE ALREADY FULLY | | INSERTED. THE LICENSEE BELIEVES THAT THE CAUSE WAS DUE TO A BAD RELAY IN | | THE RPS M/G SET, BUT IT IS STILL INVESTIGATING. THERE WERE NO SURVEILLANCE | | ACTIVITIES IN PROGRESS AT THE TIME OF THE TRIP. BECAUSE THE STANDBY GAS | | TREATMENT SYSTEM WAS IN PULL TO LOCK, IT DID NOT AUTOMATICALLY START. ALL | | SYSTEMS WERE RETURNED TO NORMAL ALIGNMENT WITHIN 30 MINUTES. | | | | THE RESIDENT INSPECTOR AND THE STATE WILL BE NOTIFIED WILL BE NOTIFIED BY | | THE LICENSEE. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28709 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: HOPE CREEK REGION: 1 |NOTIFICATION DATE: 04/20/95 | |UNIT: [1] [ ] [ ] STATE: NJ |NOTIFICATION TIME: 09:50 [ET]| |RX TYPE: [1] GE-4 |EVENT DATE: 04/20/95 | +------------------------------------------------+EVENT TIME: 06:34[EDT]| |NRC NOTIFIED BY: ED JOHNSON |LAST UPDATE DATE: 04/20/95 | |HQ OPS OFFICER: LEIGH TROCINE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |WILLIAM RULAND RDO | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N Y 100 POWER OPERATION | 100 POWER OPERATION | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AUTOMATIC START OF A SERVICE WATER PUMP WITHOUT A VALID INITIATION SIGNAL | | PRESENT. | | | | THE "A" SERVICE WATER PUMP AUTOMATICALLY STARTED WITHOUT A VALID INITIATION | | SIGNAL PRESENT. THE ROOT CAUSE OF THIS EVENT IS CURRENTLY UNDER | | INVESTIGATION, BUT THE LICENSEE SUSPECTS THAT IT WAS POSSIBLY DUE TO THE | | UNEXPLAINED GENERATION OF A PROCESS START SIGNAL. | | | | HOPE CREEK UNIT ONE HAS TWO LOOPS WITH TWO SERVICE WATER PUMPS IN EACH | | LOOP. ONLY ONE PUMP IS REQUIRED TO BE OPERATIONAL IN EACH LOOP. | | | | PRIOR TO THE AUTOMATIC START OF THE "A" SERVICE WATER PUMP, THERE WERE TWO | | SERVICE WATER PUMPS IN SERVICE (ONE OPERATING IN EACH LOOP), AND THE "A" | | SERVICE WATER PUMP WAS IN A STANDBY ALIGNMENT. THERE WERE NO SURVEILLANCE | | OR MAINTENANCE ACTIVITIES BEING PERFORMED AT THE TIME OF THE EVENT, AND NO | | ALARMS OR INDICATIONS WERE RECEIVED TO INDICATE THE REASON FOR THE | | AUTOMATIC START. THE LICENSEE LEFT THE "A" SERVICE WATER PUMP RUNNING IN | | ADDITIONAL TO THE TWO IN-SERVICE PUMPS, AND NO ADDITIONAL PROBLEMS HAVE | | BEEN IDENTIFIED. | | | | THE NRC RESIDENT INSPECTOR WAS NOTIFIED BY THE LICENSEE, AND THE LICENSEE | | INTENDS TO NOTIFY THE LOCAL TOWNSHIP. | +------------------------------------------------------------------------------+