U.S. Nuclear Regulatory Commission Operations Center Event Reports For 08/08/95 - 08/09/95 ** EVENT NUMBERS ** 29168 29169 29170 29171 29172 +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 29168 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: DIABLO CANYON REGION: 4 |NOTIFICATION DATE: 08/08/95 | |UNIT: [1] [2] [ ] STATE: CA |NOTIFICATION TIME: 15:21 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 08/08/95 | +------------------------------------------------+EVENT TIME: 15:21[PDT]| |NRC NOTIFIED BY: MAGRUDER |LAST UPDATE DATE: 08/08/95 | |HQ OPS OFFICER: BOB STRANSKY +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |HARRELL 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 100 POWER OPERATION | 100 POWER OPERATION | | 2 | N Y 100 POWER OPERATION | 100 POWER OPERATION | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | POTENTIAL FOR DOUBLE SEQUENCING OF SAFETY-RELATED ELECTRICAL LOADS DURING | | ACCIDENT CONDITIONS. | | | | THE FOLLOWING IS TEXT OF A FACSIMILE SUBMITTED BY THE LICENSEE: | | | | "A SAFETY INJECTION SIGNAL WILL RESULT IN TRANSFER OF VITAL 4KV LOADS FROM | | THE AUXILIARY TRANSFORMERS TO THE STARTUP TRANSFORMERS. ADDITIONALLY, | | ENGINEERED SAFEGUARDS FEATURE (ESF) LOADS WILL BE ADDED TO THE 4KV BUSSES. | | THIS RESULTS IN AN INCREASE IN THE LOAD ON THE 230 KV OFFSITE STARTUP POWER | | SOURCE. IF ONLY ONE OF THE TWO 230 KV STARTUP POWER SOURCES IS IN SERVICE | | (THE LINE FROM MORROW BAY OR THE LINE FROM MESA SUBSTATION), THE VOLTAGE | | WILL TEMPORARILY DECREASE ON THE 230 KV BUS DURING A BUS TRANSFER AND | | SUBSEQUENT BUS LOADING. THIS VOLTAGE DROP IS POTENTIALLY LARGE ENOUGH THAT | | IT WILL RESULT IN VOLTAGE ON THE VITAL 4KV BUSSES DROPPING BELOW THE SECOND | | LEVEL UNDERVOLTAGE RELAY (SLUR) SETPOINT. | | | | IF THE 4KV BUS VOLTAGE REMAINS BELOW THE SLUR RESET SETPOINT FOR A | | SUFFICIENT PERIOD OF TIME, THE VITAL 4KV BUSSES WILL SHED FROM THE STARTUP | | TRANSFORMER AND LOAD ONTO THEIR DIESEL GENERATORS. THIS SHEDDING FROM THE | | STARTUP TRANSFORMER AND RELOADING ONTO THE EDGs IS REFERRED TO AS DOUBLE | | SEQUENCING. DOUBLE SEQUENCING RESULTS IN STARTING AND STOPPING ESF PUMPS, | | FANS, AND VALVE MOTOR OPERATORS. THE SAFETY ANALYSES DO NOT MODEL STARTING | | AND STOPPING OF THE ESF EQUIPMENT. | | | | IN 1991 DCPP INCREASED THE SLUR VOLTAGE SETPOINT. IT HAS NOW BEEN | | DETERMINED THAT, WITH THIS CURRENT SETPOINT, THE ABOVE DOUBLE SEQUENCING | | EVENT COULD OCCUR UPON A SAFETY INJECTION SIGNAL. ON THREE OCCASIONS SINCE | | THE SLUR VOLTAGE SETPOINT WAS INCREASED IN 1991, DCPP HAS HAD ONE OF THE | | TWO STARTUP POWER LINES INTO THE PLANT OUT OF SERVICE; ONCE FOR A PERIOD OF | | 4 HOURS, ONCE FOR A PERIOD OF 9 HOURS, AND ONCE FOR A PERIOD OF 10 HOURS. | | IN ACCORDANCE WITH 10 CFR50.72(b)(1)(ii)(B) DCCP IS MAKING A ONE HOUR | | NON-EMERGENCY REPORT FOR BEING IN A CONDITION THAT WAS OUTSIDE DESIGN BASIS | | OF THE PLANT ON THE ABOVE THREE OCCASIONS." | | | | THE NRC RESIDENT INSPECTOR WILL BE INFORMED BY THE LICENSEE. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 29169 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: MILLSTONE REGION: 1 |NOTIFICATION DATE: 08/08/95 | |UNIT: [ ] [2] [ ] STATE: CT |NOTIFICATION TIME: 15:29 [ET]| |RX TYPE: [1] GE-3,[2] CE,[3] W-4-LP |EVENT DATE: 08/08/95 | +------------------------------------------------+EVENT TIME: 14:53[EDT]| |NRC NOTIFIED BY: BAIN |LAST UPDATE DATE: 08/09/95 | |HQ OPS OFFICER: BOB STRANSKY +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |JOYNER RDO | |ARPS 50.72(b)(2)(ii) RPS ACTUATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | | | 2 | M/R Y 62 POWER OPERATION | 0 HOT STANDBY | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | MANUAL REACTOR TRIP DUE TO STEAM LEAK IN TURBINE BUILDING. | | | | CONTROL ROOM OPERATORS MANUALLY TRIPPED THE REACTOR FOLLOWING THE RUPTURE | | OF A MAIN STEAM HEATER DRAIN LINE, WHICH CAUSED A LARGE STEAM LEAK IN THE | | TURBINE BUILDING. ALL CONTROL RODS INSERTED PROPERLY, AND UNIT POST-TRIP | | RESPONSE WAS NORMAL. THE LICENSEE STATED THAT NO PERSONNEL WERE INJURED | | DUE TO THE STEAM LEAK. | | | | THE LICENSEE PLANS TO INVESTIGATE THE CAUSE OF THE DRAIN LINE RUPTURE. THE | | NRC RESIDENT INSPECTOR HAS BEEN INFORMED BY THE LICENSEE. | | | | *** UPDATE @ 0415 EDT ON 8/9/95 TAKEN BY McGINTY DURING MORNING STATUS *** | | THE RUPTURE OCCURRED ON THE RECIRC LINE (JUST DOWNSTREAM OF THE ISOLATION | | VALVE) OFF OF THE 'B' HEATER DRAIN PUMP. OPERATORS SHUT THE MSIV's, HEATER | | DRAINS AND THE CONDENSATE SYSTEM DURING POST-TRIP RESPONSE TO THE STEAM | | LEAK. THE RUPTURED LINE IS A 6 OR 8 INCH LINE. THE RUPTURE WAS DESCRIBED | | AS A SPLIT IN THE PIPE, OF AT LEAST APPROXIMATELY A TWELVE INCH LENGTH. THE | | LICENSEE WAS PREVIOUSLY HAVING SOME PROBLEMS WITH THE SEALS OF THE HEATER | | DRAIN PUMPS, AND WERE REDUCED IN POWER FOR WORK ON THE 'A' HEATER DRAIN | | PUMP. WHEN THE RUPTURE OCCURRED, POWER WAS BEING REDUCED TO ALSO REMOVE | | THE 'B' HEATER DRAIN PUMP FROM SERVICE. WHEN THE 'B'HEATER DRAIN PUMP WAS | | SECURED, THE STEAM LEAK OCCURRED. THE LICENSEE WILL BE INVESTIGATING THE | | PROBLEM. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 29170 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: LIMERICK REGION: 1 |NOTIFICATION DATE: 08/08/95 | |UNIT: [ ] [2] [ ] STATE: PA |NOTIFICATION TIME: 15:50 [ET]| |RX TYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 08/08/95 | +------------------------------------------------+EVENT TIME: 13:37[EDT]| |NRC NOTIFIED BY: SOSSON |LAST UPDATE DATE: 08/08/95 | |HQ OPS OFFICER: BOB STRANSKY +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |JOYNER RDO | |ARPS 50.72(b)(2)(ii) RPS 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 SHUTDOWN | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AUTOMATIC REACTOR SCRAM DUE TO REACTOR VESSEL HIGH WATER LEVEL. | | | | THE UNIT AUTOMATICALLY SCRAMMED DUE TO A MAIN TURBINE TRIP WHEN REACTOR | | VESSEL WATER LEVEL REACHED THE HIGH WATER LEVEL TRIP POINT OF +54 INCHES. | | REACTOR VESSEL WATER LEVEL INCREASED DUE TO A PERTURBATION IN THE REACTOR | | FEEDWATER LEVEL CONTROL SYSTEM. ALL CONTROL RODS INSERTED FOLLOWING THE | | SCRAM, AND ALL SYSTEMS FUNCTIONED AS REQUIRED. MINIMUM REACTOR VESSEL | | WATER LEVEL FOLLOWING THE SCRAM WAS -33", AND MAXIMUM PRESSURE OBSERVED WAS | | 1096 PSIG. THE HPCI AND RCIC SYSTEMS DID NOT INJECT TO THE REACTOR VESSEL. | | | | THE CAUSE OF THE PERTURBATION IS UNDER INVESTIGATION, BUT THE LICENSEE | | SUSPECTS A FAULTY CONTROL POWER SUPPLY. THE LICENSEE STATED THAT SEVERAL | | PROBLEMS HAD BEEN EXPERIENCED WITH THE FEEDWATER LEVEL CONTROL SYSTEM PRIOR | | TO THE SCRAM. THE FEEDWATER CONTROL SYSTEM HAD BEEN PLACED IN SINGLE | | ELEMENT CONTROL MODE FROM THREE ELEMENT CONTROL MODE DUE TO AN ANOMALOUS | | FEEDWATER FLOW SIGNAL. IMMEDIATELY BEFORE THE SCRAM, THE 2A FEEDWATER PUMP | | CONTROLLER LOCKED UP DUE TO A LOSS OF CONTROL SIGNAL, FOLLOWED BY A REACTOR | | RECIRCULATION PUMP RUNBACK, REDUCING REACTOR POWER. OPERATORS ATTEMPTED TO | | TAKE MANUAL CONTROL OF THE FEEDWATER PUMPS, BUT WERE UNABLE TO PREVENT THE | | REACTOR VESSEL LEVEL INCREASE. | | | | THE NRC RESIDENT INSPECTOR HAS BEEN INFORMED BY THE LICENSEE. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |GENERAL INFORMATION or OTHER | |EVENT NUMBER: 29171 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |LICENSEE: BASIN RESOURCES |NOTIFICATION DATE: 08/08/95 | | CITY: WESTIN REGION: 4 |NOTIFICATION TIME: 16:38 [ET]| | COUNTY: STATE: CO |EVENT DATE: 08/08/95 | |LICENSE#: AGREEMENT: Y |EVENT TIME: 00:00[MDT]| | DOCKET: |LAST UPDATE DATE: 08/08/95 | | +-----------------------------+ | |PERSON ORGANIZATION| | |HARRELL RDO | | |COOL EO | +------------------------------------------------+ | |NRC NOTIFIED BY: PENTECOST | | |HQ OPS OFFICER: BOB STRANSKY | | +------------------------------------------------+ | |EMERGENCY CLASS: NOT APPLICABLE | | |10 CFR SECTION: | | |NAGR AGREEMENT STATE | | | | | | | | | | | | | | +------------------------------------------------+-----------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE COLORADO DEPARTMENT OF HEALTH CALLED TO REPORT A LOST Cs-137 SOURCE. | | | | A 100mCi Cs-137 SEALED SOURCE INSTALLED IN A K-RAY MODEL 7062BP FLUID | | DENSITY METER WAS LOST FROM BASIN RESOURCES IN WESTIN, CO BETWEEN OCTOBER | | 1994 AND APRIL 1995. THE STATE IS DISPATCHING SEVERAL PEOPLE TO THE | | FACILITY TO PERFORM A RADIOLOGICAL SURVEY. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 29172 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: MILLSTONE REGION: 1 |NOTIFICATION DATE: 08/09/95 | |UNIT: [ ] [2] [ ] STATE: CT |NOTIFICATION TIME: 05:35 [ET]| |RX TYPE: [1] GE-3,[2] CE,[3] W-4-LP |EVENT DATE: 08/09/95 | +------------------------------------------------+EVENT TIME: 04:24[EDT]| |NRC NOTIFIED BY: BAIN |LAST UPDATE DATE: 08/09/95 | |HQ OPS OFFICER: TIM McGINTY +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: | | |ARPS 50.72(b)(2)(ii) RPS ACTUATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | | | 2 | A N 0 HOT STANDBY | 0 HOT STANDBY | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AUTOMATIC REACTOR TRIP SIGNAL GENERATED ON LOW STEAM GENERATOR LEVEL WHEN | | AN ATMOSPHERIC DUMP FAILED OPEN WHILE IN HOT STANDBY. | | | | THE LICENSEE REPORTED AN AUTOMATIC REACTOR PROTECTION SYSTEM ACTUATION. THE | | TRIP WAS ON LOW STEAM GENERATOR LEVEL IN THE #2 STEAM GENERATOR, CAUSED BY | | AN UNCONTROLLED COOLDOWN FROM THE #2 STEAM GENERATOR. UNIT 2 WAS ALREADY | | SHUTDOWN DUE TO THE REACTOR TRIP REPORTED IN EVENT #29169. ALL RODS | | REMAINED FULLY INSERTED. | | | | THE CAUSE OF THE UNCONTROLLED COOLDOWN WAS THAT THE ATMOSPHERIC DUMP OFF OF | | THE #2 STEAM GENERATOR FAILED OPEN. OPERATORS MANUALLY TRIPPED THE PLANT | | PER PROCEDURE (UNCONTROLLED STEAM DEMAND) UPON RECEIVING THE LOW #2 STEAM | | GENERATOR LEVEL ALARM, HOWEVER A VALID AUTOMATIC REACTOR TRIP SIGNAL WAS | | ALSO GENERATED. THE CAUSE OF THE ATMOSPHERIC DUMP VALVE OPENING IS UNKNOWN | | AND BEING INVESTIGATED. THE LICENSEE NOTIFIED THE RESIDENT INSPECTOR AND | | LOCAL OFFICIALS. | +------------------------------------------------------------------------------+