U.S. Nuclear Regulatory Commission Operations Center Event Reports For 03/11/97 - 03/12/97 ** EVENT NUMBERS ** 31927 31928 31929 31930 31931 31932 31933 31934 31935 +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31927 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: SUSQUEHANNA REGION: 1 |NOTIFICATION DATE: 03/11/97 | |UNIT: [ ] [2] [ ] STATE: PA |NOTIFICATION TIME: 05:30 [ET]| |RX TYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 03:30[EST]| |NRC NOTIFIED BY: RADISHOFSKI |LAST UPDATE DATE: 03/11/97 | |HQ OPS OFFICER: JOHN MacKINNON +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |JENNY JOHANSEN RDO | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | | | 2 | N Y 88 POWER OPERATION | 88 POWER OPERATION | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE 'B' REACTOR PROTECTION SYSTEM (RPS) NORMAL POWER SUPPLY FAILED CAUSING | | A DIVISION II HALF SCRAM AND SEVERAL ENGINEERED SAFETY FEATURE ACTUATIONS. | | | | THE RPS NORMAL POWER SUPPLY FAILED CAUSING A DIVISION II HALF SCRAM. THE | | FOLLOWING OCCURRED DUE TO THE LOSS OF ELECTRICAL POWER FROM THE 'B' RPS | | MOTOR-GENERATOR SET: | | | | 1. ISOLATION OF THE REACTOR WATER CLEANUP SYSTEM, | | 2. ISOLATION OF SECONDARY CONTAINMENT ZONES II AND III VENTILATION, | | 3. INITIATION OF THE STANDBY GAS TREATMENT SYSTEM, | | 4. INITIATION OF THE CONTROL ROOM EMERGENCY OUTSIDE AIR SUPPLY SYSTEM, | | 5. ISOLATION OF BOTH DIVISIONS OF THE CONTAINMENT RADIATION MONITORING | | SYSTEM, AND | | 6. DIVISION II PRIMARY CONTAINMENT ISOLATION VALVES. | | | | THE RPS WAS PLACED ON ITS ALTERNATE POWER SUPPLY, AND AN EVALUATION OF | | PLANT RESPONSE TO THE LOSS OF THE POWER SUPPLY WAS PERFORMED. ALL | | EQUIPMENT ACTUATED AS EXPECTED FOR THIS OCCURRENCE. THE HALF SCRAM WAS | | RESET. ALL OTHER EQUIPMENT INITIATIONS AND ISOLATIONS WERE SECURED AND | | RESET IN ACCORDANCE WITH PLANT PROCEDURES. | | | | THE 'B' RPS NORMAL POWER SUPPLY MOTOR-GENERATOR SET WAS DE-ENERGIZED AND | | REMOVED FROM SERVICE FOR INVESTIGATION AND REPAIRS. THE LICENSEE THINKS | | THAT THERE MAY BE A VOLTAGE REGULATOR PROBLEM WITH THE RPS MOTOR GENERATOR. | | | | THE NRC RESIDENT INSPECTOR WILL BE NOTIFIED BY THE LICENSEE OF THIS EVENT. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |FUEL CYCLE FACILITY | |EVENT NUMBER: 31928 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: WESTINGHOUSE ELECTRIC CORPORATION |NOTIFICATION DATE: 03/11/97 | | RXTYPE: URANIUM FUEL FABRICATION |NOTIFICATION TIME: 13:06 [ET]| |COMMENTS: LEU CONVERSION (UF6 to UO2) |EVENT DATE: 03/11/97 | | COMMERCIAL LWR FUEL |EVENT TIME: 03:15[EST]| | |LAST UPDATE DATE: 03/11/97 | | CITY: COLUMBIA REGION: 2 +-----------------------------+ | COUNTY: RICHLAND STATE: SC |PERSON ORGANIZATION| |LICENSE#: SNM-1107 AGREEMENT: Y |AL BELISLE RDO | | DOCKET: 07001151 | | +------------------------------------------------+ | |NRC NOTIFIED BY: ED REITLER | | |HQ OPS OFFICER: RUDY KARSCH | | +------------------------------------------------+ | |EMERGENCY CLASS: NOT APPLICABLE | | |10 CFR SECTION: | | |KBCA 70.50(b)(3) MED TREAT INVOLV CONT | | | | | | | | | | | | | | +------------------------------------------------+-----------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AN OPERATOR WAS CUT BY A PIECE OF MOVING EQUIPMENT. THE CONTAMINATED | | WORKER WAS TREATED AT A LOCAL HOSPITAL. RESIDUAL CONTAMINATION REMAINED ON | | THE WORKER'S INJURED HAND; HOWEVER, NO CONTAMINATION WAS DETECTED AT THE | | HOSPITAL AS A RESULT OF THE INDIVIDUAL'S TREATMENT. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31929 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: COOK REGION: 3 |NOTIFICATION DATE: 03/11/97 | |UNIT: [ ] [2] [ ] STATE: MI |NOTIFICATION TIME: 14:11 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 10:56[EST]| |NRC NOTIFIED BY: MARY BETH DEPUYDT |LAST UPDATE DATE: 03/11/97 | |HQ OPS OFFICER: RUDY KARSCH +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |WAYNE KROPP 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 | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | | | 2 | A/R Y 100 POWER OPERATION | 0 HOT STANDBY | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | A REACTOR TRIP OCCURRED DUE TO LOW STEAM GENERATOR LEVEL COINCIDENT WITH A | | STEAM FLOW/FEEDWATER FLOW MISMATCH CAUSED BY THE FAILURE OF A FEEDWATER | | REGULATING VALVE CONTROLLER. | | | | THE CONTROLLER FOR FEEDWATER REGULATING VALVE '210' FAILED FOR UNKNOWN | | REASONS. THIS CAUSED A LOW LEVEL IN STEAM GENERATOR #1 COINCIDENT WITH A | | STEAM FLOW/FEEDWATER FLOW MISMATCH, WHICH CAUSED A REACTOR TRIP. ALL | | CONTROL RODS FULLY INSERTED, AND BOTH THE MOTOR-DRIVEN AND TURBINE-DRIVEN | | AUXILIARY FEEDWATER PUMPS STARTED. AFTER WATER LEVEL WAS RECOVERED IN THE | | STEAM GENERATORS, THE TURBINE-DRIVEN PUMP WAS SECURED, BUT LATER, IT | | RESTARTED AUTOMATICALLY DUE TO LEVEL OSCILLATIONS IN THE STEAM GENERATORS. | | | | WHEN THE LICENSEE ATTEMPTED TO PUT THE MAIN TURBINE ONTO THE TURNING GEAR | | FOLLOWING THE TRIP, IT WAS DISCOVERED THAT THE TURNING GEAR MOTOR HAD | | FAILED. AN ALTERNATE MEANS WAS USED TO TURN THE TURBINE. DECAY HEAT | | REMOVAL IS VIA THE MAIN CONDENSER. THE LICENSEE IS INVESTIGATING THE CAUSE | | OF THE CONTROLLER FAILURE. | | | | THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |HOSPITAL | |EVENT NUMBER: 31930 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |LICENSEE: GUNDERSEN CLINIC |NOTIFICATION DATE: 03/11/97 | | CITY: LA CROSSE REGION: 3 |NOTIFICATION TIME: 16:41 [ET]| | COUNTY: LA CROSSE STATE: WI |EVENT DATE: 03/06/97 | |LICENSE#: 48-01277-02 AGREEMENT: N |EVENT TIME: 16:45[CST]| | DOCKET: |LAST UPDATE DATE: 03/11/97 | | +-----------------------------+ | |PERSON ORGANIZATION| | |WAYNE KROPP RDO | | | | +------------------------------------------------+ | |NRC NOTIFIED BY: DAN MARVEL | | |HQ OPS OFFICER: RUDY KARSCH | | +------------------------------------------------+ | |EMERGENCY CLASS: NOT APPLICABLE | | |10 CFR SECTION: | | |LADM 35.33(a) MED MISADMINISTRATION | | | | | | | | | | | | | | +------------------------------------------------+-----------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE PRESCRIBED DOSE WAS 20 mCi OF IODINE-131; HOWEVER, THE TECHNICIAN GAVE | | A 10-mCi DOSE. THE PHYSICIAN HAS BEEN NOTIFIED. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31931 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: ZION REGION: 3 |NOTIFICATION DATE: 03/11/97 | |UNIT: [1] [ ] [ ] STATE: IL |NOTIFICATION TIME: 17:45 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 15:54[CST]| |NRC NOTIFIED BY: WINTERS |LAST UPDATE DATE: 03/11/97 | |HQ OPS OFFICER: RUDY KARSCH +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: UNUSUAL EVENT +-----------------------------+ |10 CFR SECTION: |WAYNE KROPP RDO | |AAEC 50.72(a)(1)(i) EMERGENCY DECLARED |STUART RICHARDS, NRR EO | |AESF 50.72(b)(2)(ii) ESF ACTUATION |BOB CALDWELL FEMA | | |STU RUBIN, IRD AEOD | | |AL CHAFFEE NRR | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N N 0 COLD SHUTDOWN | 0 COLD SHUTDOWN | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE LICENSEE DECLARED AN UNUSUAL EVENT AT 1617 CST DUE TO THE LOSS OF | | OFFSITE POWER TO UNIT 1, i.e., LOSS OF THE SYSTEM AUXILIARY TRANSFORMER AND | | THE SUBSEQUENT STARTING AND LOADING OF THE EMERGENCY DIESEL GENERATORS | | (EDG). | | | | THE SYSTEM AUXILIARY TRANSFORMER [WHICH SUPPLIES POWER TO THE ENGINEERED | | SAFETY FEATURE (ESF) BUSES] TRIPPED, AND THE DELUGE SYSTEM ACTUATED FOR | | UNKNOWN REASONS. ALL THREE SITE EDGs STARTED AND SUPPLIED POWER TO THE ESF | | BUSES. SHUTDOWN COOLING WAS LOST FOR 8 MINUTES DUE TO THE INTERRUPTION IN | | POWER, AND AN INCREASE IN COOLANT TEMPERATURE FROM 92øF TO 112øF WAS | | OBSERVED. THE EDGs ARE STILL RUNNING AND SUPPLYING POWER FOR THE RESIDUAL | | HEAT REMOVAL (RHR) SYSTEM. | | | | OFF-SITE POWER IS AVAILABLE FROM UNIT 2; HOWEVER, THE LICENSEE HAS CHOSEN | | TO CONTINUE RUNNING THE EDGs WHILE TROUBLESHOOTING THE SYSTEM AUXILIARY | | TRANSFORMER PROBLEM. THE CRITERION FOR TERMINATING THE UNUSUAL EVENT IS | | THE RESTORATION OF RELIABLE OFF-SITE POWER TO THE ESF BUSES. THE LICENSEE | | PLANS TO INFORM THE NRC RESIDENT INSPECTOR. | | | | * * * 1950 EST MARCH 11, 1997, UPDATE FROM WINTERS TAKEN BY KARSCH * * * | | | | THE LICENSEE HAS RESTORED OFF-SITE POWER TO BUS '147' VIA THE UNIT 2 SYSTEM | | AUXILIARY TRANSFORMER. BOTH TRAINS OF RHR ARE CURRENTLY BEING POWERED BY | | BUSES '148' AND '149' WHICH ARE IN TURN BEING POWERED BY THE 'A' AND 'B' | | EDGs, RESPECTIVELY. THE LICENSEE PLANS TO ACTIVATE ITS TECHNICAL SUPPORT | | CENTER. THE NRR EO (RICHARDSON) AND R3DO (KROPP) WERE NOTIFIED BY THE NRC | | OPERATIONS CENTER. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31932 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: OYSTER CREEK REGION: 1 |NOTIFICATION DATE: 03/11/97 | |UNIT: [1] [ ] [ ] STATE: NJ |NOTIFICATION TIME: 17:45 [ET]| |RX TYPE: [1] GE-2 |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 17:10[EST]| |NRC NOTIFIED BY: JIM RUMBIN |LAST UPDATE DATE: 03/11/97 | |HQ OPS OFFICER: RUDY KARSCH +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |JENNY JOHANSEN RDO | |AOUT 50.72(b)(1)(ii)(B) OUTSIDE DESIGN BASIS | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N Y 95 POWER OPERATION | 100 POWER OPERATION | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE LICENSEE OPENED A VALVE FOR MAINTENANCE PROVIDING A PATHWAY FOR SOME | | STEAM TO VENT ABOVE THE SURFACE OF THE SUPPRESSION POOL. | | | | THE 'V2118' VALVE (A SPRAY VALVE LOCATED ON TOP OF THE TORUS) WAS MANUALLY | | STROKED OPEN, LUBRICATED, AND THEN MANUALLY STROKED CLOSED. WHILE THIS | | VALVE WAS OPEN (ABOUT 5 TO 10 MINUTES), THE SUBMERGENCE COOLING FEATURE OF | | THE SUPPRESSION POOL WAS COMPROMISED. APPARENTLY, A TEST VALVE IN SERIES | | WITH THE SPRAY VALVE HAD PREVIOUSLY BEEN OPENED, AND OPERATION WITH BOTH OF | | THESE VALVES OPEN WAS A CONDITION OUTSIDE THE DESIGN BASIS OF THE PLANT. | | | | THE LICENSEE PLANS TO INFORM THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31933 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: HADDAM NECK REGION: 1 |NOTIFICATION DATE: 03/11/97 | |UNIT: [1] [ ] [ ] STATE: CT |NOTIFICATION TIME: 18:18 [ET]| |RX TYPE: [1] W-4-LP |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 18:03[EST]| |NRC NOTIFIED BY: DOUGLAS McCRACKEN |LAST UPDATE DATE: 03/11/97 | |HQ OPS OFFICER: RUDY KARSCH +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |JENNY JOHANSEN RDO | |ADAS 50.72(b)(2)(i) DEG/UNANALYZED COND | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N N 0 REFUELING | 0 REFUELING | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE LICENSEE DETERMINED THAT A LOSS OF NORMAL POWER FOLLOWED BY RESTART OF | | THE SERVICE WATER PUMPS COULD CAUSE A WATER HAMMER IN THE LINE TO THE SPENT | | FUEL POOL HEAT EXCHANGER AND COULD CAUSE A FAILURE OF THE LINE. A SERVICE | | WATER LINE BREAK WOULD HAVE PUT THE PLANT INTO AN UNANALYZED CONDITION IF | | IT HAD OCCURRED WHILE THE PLANT WAS AT POWER (HISTORICAL CONDITION), AND | | NOW THAT THE PLANT IS DEFUELED IT RENDERS THE SPENT FUEL POOL COOLING | | SYSTEM INOPERABLE. THE LICENSEE HAS TAKEN COMPENSATORY MEASURES TO | | MAINTAIN OPERABILITY IF A LINE BREAK SHOULD OCCUR. THE LICENSEE HAS STAGED | | HOSES AND FITTINGS SO HEAT EXCHANGER COOLING COULD BE PROVIDED USING THE | | FIRE WATER SYSTEM. | | | | THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31934 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: LASALLE REGION: 3 |NOTIFICATION DATE: 03/11/97 | |UNIT: [1] [2] [ ] STATE: IL |NOTIFICATION TIME: 21:38 [ET]| |RX TYPE: [1] GE-5,[2] GE-5 |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 19:45[CST]| |NRC NOTIFIED BY: JAY HOUSTON |LAST UPDATE DATE: 03/11/97 | |HQ OPS OFFICER: RUDY KARSCH +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: UNUSUAL EVENT +-----------------------------+ |10 CFR SECTION: |WAYNE KROPP RDO | |AAEC 50.72(a)(1)(i) EMERGENCY DECLARED |STUART RICHARDS, NRR EO | | |KNUPP FEMA | | |STU RUBIN, IRD AEOD | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N N 0 COLD SHUTDOWN | 0 COLD SHUTDOWN | | 2 | N N 0 REFUELING | 0 REFUELING | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE LICENSEE DECLARED AN UNUSUAL EVENT AT 1945 CST WHEN LAKE LEVEL ROSE | | ABOVE THE MAXIMUM ALLOWED FINAL SAFETY ANALYSIS REPORT (FSAR) VALUE. | | | | THE MAXIMUM LAKE LEVEL ALLOWED BY THE LICENSEE'S FSAR IS 701 FEET, AND THE | | LAKE LEVEL IS NOW AT 701.8 FEET. THE LAKE LEVEL BLOWDOWN VALVE IS BROKEN, | | AND RAIN IS FORECAST. THE LICENSEE, THEREFORE, EXPECTS THAT LAKE LEVEL | | MIGHT INCREASE IN THE NEAR FUTURE. THE LICENSEE IS ATTEMPTING TO HAVE | | DIVERS REPAIR THE BLOWDOWN VALVE. IN ADDITION, PERSONNEL ARE MONITORING | | THE LOWER ELEVATIONS IN THE PLANT, AND THE ENGINEERING DEPARTMENT IS | | RE-EVALUATING THE 701-FOOT LEVEL LIMIT. | | | | THE LICENSEE IS ACTIVATING ITS TECHNICAL SUPPORT CENTER AND HAS NOTIFIED | | STATE GOVERNMENT AGENCIES AND THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 31935 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: LIMERICK REGION: 1 |NOTIFICATION DATE: 03/12/97 | |UNIT: [1] [ ] [ ] STATE: PA |NOTIFICATION TIME: 00:23 [ET]| |RX TYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 03/11/97 | +------------------------------------------------+EVENT TIME: 22:09[EST]| |NRC NOTIFIED BY: ROBERT KUBO |LAST UPDATE DATE: 03/12/97 | |HQ OPS OFFICER: LEIGH TROCINE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |JENNY JOHANSEN RDO | |AESF 50.72(b)(2)(ii) ESF ACTUATION | | |NLCO TECH SPEC LCO A/S | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | REACTOR WATER CLEANUP (RWCU) SYSTEM ISOLATIONS DUE TO HIGH DIFFERENTIAL | | FLOW ISOLATION SIGNALS WHICH WERE CAUSED FOR UNKNOWN REASONS | | | | AT 2209 ON MARCH 11, 1997, THE ALARM INDICATING INITIATION OF AN RWCU | | SYSTEM HIGH DIFFERENTIAL FLOW ISOLATION TIMER WAS RECEIVED WHILE THE | | LICENSEE WAS IN THE PROCESS OF RETURNING THE '1A' RWCU FILTER DEMINERALIZER | | TO SERVICE FOLLOWING FILTER REGENERATION. THIS 45-SECOND TIMER TIMED OUT, | | AND AN INBOARD RWCU SYSTEM ISOLATION SIGNAL WAS RECEIVED. THIS SIGNAL | | CAUSED VALVE HV-044-1F001 TO CLOSE. THE SYSTEM RESPONDED TO THIS SIGNAL AS | | EXPECTED. HOWEVER, THE CAUSE OF THE SIGNAL WAS UNKNOWN. | | | | THE SYSTEM WAS SECURED IN ACCORDANCE WITH THE SYSTEM OPERATING PROCEDURE, | | AND AN INVESTIGATION WAS CONDUCTED TO DETERMINE THE CAUSE OF THE ISOLATION. | | THE ISOLATION SIGNAL WAS RESET IN ACCORDANCE WITH A GENERAL PLANT OPERATING | | PROCEDURE. HOWEVER, DURING AN ATTEMPT TO RESTORE THE SYSTEM TO SERVICE PER | | THE SYSTEM OPERATING PROCEDURE, ANOTHER HIGH DIFFERENTIAL FLOW ISOLATION | | SIGNAL CAUSED BOTH INBOARD AND OUTBOARD RWCU SYSTEM ISOLATIONS (CLOSURE OF | | VALVES HV-044-1F001 AND HV-044-1F004). THE SYSTEM WAS SECURED PER THE | | SYSTEM SHUTDOWN PROCEDURE, AND AN INVESTIGATION TO DETERMINE THE CAUSE OF | | THE ISOLATION SIGNALS CONTINUES. | | | | BECAUSE THERE IS NO CONDUCTIVITY MONITOR DUE TO THE CURRENT SYSTEM | | CONFIGURATION, THE UNIT IS CURRENTLY IN A TECHNICAL SPECIFICATION LIMITING | | CONDITION FOR OPERATION. PER THIS LIMITING CONDITION FOR OPERATION, | | CHEMISTRY PERSONNEL PLAN TO TAKE GRAB SAMPLES EVERY EIGHT HOURS. | | | | THE LICENSEE PLANS TO NOTIFY THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+