U.S. Nuclear Regulatory Commission Operations Center Event Reports For 05/31/95 - 06/01/95 ** EVENT NUMBERS ** 28768 28866 28869 28870 28871 28872 28873 !!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!!! +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28768 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: MILLSTONE REGION: 1 |NOTIFICATION DATE: 05/05/95 | |UNIT: [1] [ ] [ ] STATE: CT |NOTIFICATION TIME: 14:45 [ET]| |RX TYPE: [1] GE-3,[2] CE,[3] W-4-LP |EVENT DATE: 05/05/95 | +------------------------------------------------+EVENT TIME: 14:34[EDT]| |NRC NOTIFIED BY: SILKO |LAST UPDATE DATE: 05/31/95 | |HQ OPS OFFICER: DOUG WEAVER +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |RICHARD CONTE RDO | |AINA 50.72(b)(2)(iii)(A) POT UNABLE TO SAFE SD | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | AN ERROR EXISTS IN A FIRE RECOVERY PROCEDURE WHICH WOULD HAVE RENDERED SOME | | REACTOR PRESSURE MONITORING INSTRUMENTATION INOPERABLE | | | | AN ERROR IN ONE OF THE FIRE RECOVERY PROCEDURES HAS BEEN IDENTIFIED WHICH | | COULD HAVE CAUSED THE LOSS OF CERTAIN INSTRUMENTATION. SPECIFICALLY, THE | | FIRE RECOVERY PROCEDURE COULD HAVE DISABLED THE REACTOR PRESSURE | | INSTRUMENTATION WHICH IS USED TO MONITOR THE UNIT SHUTDOWN FOLLOWING A | | FIRE. CORRECTIVE ACTIONS ARE IN PROGRESS. | | | | OTHER REACTOR PRESSURE INDICATIONS WOULD HAVE BEEN AVAILABLE TO SAFELY | | SHUTDOWN THE REACTOR. HOWEVER, SOME EXPECTED PRESSURE INDICATIONS WOULD | | NOT HAVE BEEN AVAILABLE. | | | | APPROPRIATE STATE AND LOCAL OFFICIALS WERE NOTIFIED. THE LICENSEE INFORMED | | THE NRC RESIDENT INSPECTOR. | | | | * * * UPDATE AT 0851 ON 5/31/95 BY SILKO TAKEN BY WEAVER * * * | | | | THE LICENSEE HAS RETRACTED THIS EVENT. EMERGENCY OPERATING PROCEDURES | | ENCOMPASS PRESSURE INDICATIONS AND WOULD HAVE ENSURED THAT THE REACTOR WAS | | SAFELY SHUTDOWN. REACTOR PRESSURE WOULD BE AUTOMATICALLY CONTROLLED BY | | PLANT SYSTEMS UNDER THE FIRE SCENARIOS CONSIDERED. IN SUMMARY, THE | | PROCEDURAL ERROR IN THE FIRE PROCEDURE DID NOT CREATE A CONDITION THAT | | WOULD HAVE PREVENTED SAFE SHUTDOWN OF THE REACTOR. HOO NOTIFIED R1DO | | (SHANBAKY). | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28866 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: FITZPATRICK REGION: 1 |NOTIFICATION DATE: 05/30/95 | |UNIT: [1] [ ] [ ] STATE: NY |NOTIFICATION TIME: 12:20 [ET]| |RX TYPE: [1] GE-4 |EVENT DATE: 05/30/95 | +------------------------------------------------+EVENT TIME: 12:00[EDT]| |NRC NOTIFIED BY: SLIWA / RASPLEY |LAST UPDATE DATE: 05/31/95 | |HQ OPS OFFICER: DICK JOLLIFFE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: UNUSUAL EVENT +-----------------------------+ |10 CFR SECTION: |MOHAMED SHANBAKY RDO | |AAEC 50.72(a)(1)(i) EMERGENCY DECLARED |ED GOODWIN EO | |ASHU 50.72(b)(1)(i)(A) PLANT S/D REQD BY TS |WRIGHT FEMA | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | N Y 16 POWER OPERATION | 16 POWER OPERATION | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | -UE DUE TO TS REQUIRED PLANT SHUTDOWN DUE TO UNIDENTIFIED LEAK > TS LIMIT- | | | | LICENSEE HAS MEASURED A 2.9 GPM UNIDENTIFIED WATER LEAK RATE INCREASE IN | | THE DRYWELL OVER A 24-HOUR PERIOD. | | | | TECH SPEC LCO A/S 3.6.D.1.b REQUIRES THE LICENSEE TO REDUCE THE | | UNIDENTIFIED LEAK RATE TO LESS THAN A TWO GPM INCREASE IN A 24-HOUR PERIOD | | WITHIN FOUR HOURS OR PLACE THE PLANT IN AT LEAST HOT SHUTDOWN CONDITION | | WITHIN THE NEXT 12 HOURS AND COLD SHUTDOWN CONDITION WITHIN THE FOLLOWING | | 24 HOURS. | | | | LICENSEE BEGAN SHUTTING THE PLANT DOWN FROM 100% POWER AND WAS AT 16% POWER | | AND DECREASING AT THE TIME OF THE CALL TO THE NRC OPERATIONS CENTER. | | | | AT 1200, LICENSEE DECLARED AN UNUSUAL EVENT DUE TO A TECH SPEC REQUIRED | | PLANT SHUTDOWN. | | | | LICENSEE NOTIFIED STATE AND LOCAL OFFICIALS AND THE NRC RESIDENT INSPECTOR. | | | | **** UPDATE FROM SULLIVAN RECEIVED BY TROCINE AT 03:03 ON MAY 31, 1995 **** | | | | UNIT 1 ENTERED COLD SHUTDOWN AT 02:47 AND THE UNUSUAL EVENT WAS TERMINATED | | AT 02:50 ON 05/31/95. THE LICENSEE IDENTIFIED A PACKING LEAK ON A 3/4 INCH | | MANUAL VALVE OFF OF THE 'B' RECIRCULATION SUCTION VALVE. (THIS MANUAL | | VALVE IS USED FOR CHEMICAL DECONNING.) ESTIMATED RESTART DATE IS 06/01/95. | | | | THE LICENSEE NOTIFIED THE NRC RESIDENT INSPECTOR, STATE & LOCAL OFFICIALS, | | AND THE MEDIA. HOO NOTIFIED R1DO SHANBAKY, NRR EO ADENSAM, & FEMA SHULL. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28869 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: MCGUIRE REGION: 2 |NOTIFICATION DATE: 05/30/95 | |UNIT: [1] [ ] [ ] STATE: NC |NOTIFICATION TIME: 22:16 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 05/30/95 | +------------------------------------------------+EVENT TIME: 21:55[EDT]| |NRC NOTIFIED BY: MARVIN JOHNSON |LAST UPDATE DATE: 05/31/95 | |HQ OPS OFFICER: DICK JOLLIFFE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |DOUGLAS COLLINS RDO | |AARC 50.72(b)(1)(v) OTHER ASMT/COMM INOP | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | -LESS THAN 15% OF UNIT 1 CONTROL ROOM ANNUNCIATORS LOST FOR UNKNOWN REASONS | | | | UNIT 1 LOST LESS THAN 15% OF THE CONTROL ROOM ANNUNCIATOR CAPABILITY FOR | | UNKNOWN REASONS. LOST ARE THE ANNUNCIATORS FOR THE STANDBY (REMOTE) | | SHUTDOWN FACILITY, THE FIRE PROTECTION PANELS, THE INSTRUMENT AIR | | COMPRESSORS, THE HVAC BOARDS, AND THE OPERATOR AID COMPUTER PANEL. | | | | PLANT PERSONNEL ARE MONITORING LOCAL PANELS AND OPERATING EQUIPMENT LOCALLY | | UNTIL THE PROBLEM IS CORRECTED. | | | | INSTRUMENT AND CONTROL TECHNICIANS ARE INVESTIGATING THE CAUSE AND | | DETERMINING CORRECTIVE ACTIONS. | | | | LICENSEE INFORMED THE NRC RESIDENT INSPECTOR. | | | | **UPDATE DATE\TIME: 5/31/95 @ 0415 EDT *FROM LICENSEE: SMALL BY:McGINTY** | | | | THE LICENSEE REPLACED A BAD ANNUNCIATOR CARD THAT FED THE "1-AD-13, A-2, | | AND A-3" ANNUNCIATORS. THE CARD WAS CAUSING THE FUSES TO BLOW THAT FEED | | THE POWER SUPPLY FOR THOSE CABINETS. THE ANNUNCIATORS ARE NOW WORKING | | CORRECTLY AND THE WORK ORDER HAS BEEN CLOSED OUT. THE LICENSEE WILL INFORM | | THE NRC RESIDENT INSPECTOR. HOO NOTIFIED R2DO COLLINS. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28870 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: PALO VERDE REGION: 4 |NOTIFICATION DATE: 05/31/95 | |UNIT: [1] [ ] [ ] STATE: AZ |NOTIFICATION TIME: 04:34 [ET]| |RX TYPE: [1] CE,[2] CE,[3] CE |EVENT DATE: 05/30/95 | +------------------------------------------------+EVENT TIME: 22:45[MST]| |NRC NOTIFIED BY: ROBERSON |LAST UPDATE DATE: 05/31/95 | |HQ OPS OFFICER: TIM McGINTY +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |GARY SANBORN RDO | |ARPS 50.72(b)(2)(ii) RPS ACTUATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | 1 | A/R Y 65 POWER OPERATION | 0 HOT STANDBY | | | | | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | REACTOR TRIP FROM 65% DUE TO CLOSURE OF A FEEDWATER ISOLATION VALVE DURING | | THE REPLACEMENT OF A COIL IN THE SOLENOID. | | | | UNIT 1 WAS AT 65% POWER AFTER RECENTLY COMPLETING A REFUELING OUTAGE. AT | | APPROXIMATELY 2242 MST, AN AUTOMATIC REACTOR TRIP OCCURRED ON LOW STEAM | | GENERATOR LEVEL FOR SG NO. 2. PRIOR TO THE REACTOR TRIP, REPLACEMENT OF A | | COIL IN THE "D" SOLENOID OF FEEDWATER ISOLATION VALVE (FWIV) "137" WAS IN | | PROGRESS, WHEN FWIV "137" UNEXPECTEDLY CLOSED. CLOSURE OF THE FWIV CAUSED | | A LOSS OF MAIN FEEDWATER FLOW TO SG NO. 2. | | | | THE EVENT WAS CLASSIFIED AS AN UNCOMPLICATED REACTOR TRIP. THE CAUSE OF | | THE CLOSURE OF THE FWIV IS UNDER INVESTIGATION. ALL CONTROL RODS FULLY | | INSERTED INTO THE CORE, AND THE PLANT IS STABLE AT NOP/NOT. THE PLANT IS | | STEAMING AS REQUIRED TO THE MAIN CONDENSER, AND AUXILIARY FEEDWATER PUMP | | "N" IS FEEDING BOTH SG's. THERE WERE NO PROBLEMS WITH TRANSFERS OF | | ELECTRICAL BUSES, AND ALL ECCS's AND EDG's ARE OPERATIONAL. | | | | THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR AND THE STATE. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28871 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: DRESDEN REGION: 3 |NOTIFICATION DATE: 05/31/95 | |UNIT: [ ] [2] [3] STATE: IL |NOTIFICATION TIME: 17:58 [ET]| |RX TYPE: [1] GE-1,[2] GE-3,[3] GE-3 |EVENT DATE: 05/31/95 | +------------------------------------------------+EVENT TIME: 13:00[CDT]| |NRC NOTIFIED BY: J. WELCH |LAST UPDATE DATE: 05/31/95 | |HQ OPS OFFICER: DICK JOLLIFFE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |ROY CANIANO RDO | |AINC 50.72(b)(2)(iii)(C) POT UNCNTRL RAD REL | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | | | 2 | N Y 80 POWER OPERATION | 80 POWER OPERATION | | 3 | N N 0 COLD SHUTDOWN | 0 COLD SHUTDOWN | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | - SECONDARY CONTAINMENT INTEGRITY NOT ESTABLISHED ON SEVERAL OCCASIONS - | | | | DRESDEN UNIT 2 IS AT 80% POWER AND COASTING DOWN FOR A REFUELING OUTAGE. | | UNIT 3 IS IN CONDITION 4 (COLD SHUTDOWN) IN A MAINTENANCE OUTAGE. | | | | DRESDEN UNITS 2 & 3 HAVE A COMMON SECONDARY CONTAINMENT WHICH CONTAINS A | | SET OF MATERIAL ACCESS DOORS (INNER AND OUTER DOORS) FOR EACH UNIT. | | | | PRIOR TO EACH REFUELING OUTAGE, DRESDEN PERFORMS A SECONDARY CONTAINMENT | | LEAK RATE TEST. THIS TEST IS PERFORMED 5 TIMES; ONCE WITH ALL 4 DOORS | | CLOSED, ONCE WITH ONLY THE UNIT 2 INNER DOOR OPEN, ONCE WITH ONLY THE UNIT | | 2 OUTER DOOR OPEN, ONCE WITH ONLY THE UNIT 3 INNER DOOR OPEN, AND ONCE WITH | | ONLY THE UNIT 3 OUTER DOOR OPEN. THIS TEST WAS PERFORMED ON 05/31/95. | | | | AT 1300 (CDT) ON 05/31/95, THE LICENSEE DETERMINED THAT THE SECONDARY | | CONTAINMENT LEAK RATE TEST PERFORMED ON 05/31/95 FAILED WITH ONLY THE | | UNIT 3 INNER DOOR OPEN (ACCEPTANCE CRITERIA IS SECONDARY CONTAINMENT | | BEING ABLE TO MAINTAIN 0.25 INCHES OF WATER VACUUM). | | | | LICENSEE ALSO DETERMINED THAT THE SECONDARY CONTAINMENT LEAK RATE TEST | | PERFORMED PRIOR TO THE LAST UNIT 3 REFUELING OUTAGE OVER 1 YEAR AGO ALSO | | FAILED WITH ONLY THE UNIT 3 INNER DOOR OPEN. | | | | SIMPLY KEEPING ALL 4 DOORS CLOSED ESTABLISHES ACCEPTABLE SECONDARY | | CONTAINMENT INTEGRITY. | | | | A LICENSEE ADMINISTRATIVE PROCEDURE REQUIRES A PERSON TO BE STATIONED AT | | THE UNIT 3 INNER DOOR WHILE IT IS OPEN. THIS PERSON WOULD CLOSE THE DOOR | | TO ESTABLISH ACCEPTABLE SECONDARY CONTAINMENT INTEGRITY WHEN NOTIFIED OF | | THE RECEIPT OF A VALID SECONDARY CONTAINMENT ISOLATION SIGNAL. | | | | TECH SPEC LCO A/S 3.7.C.2 REQUIRES THE LICENSEE TO RESTORE SECONDARY | | CONTAINMENT INTEGRITY TO ACCEPTABLE STATUS WITHIN 4 HOURS OR TO PLACE | | BOTH UNITS IN A HOT SHUTDOWN CONDITION WITHIN THE NEXT 12 HOURS. | | | | LICENSEE BELIEVES THAT ON SEVERAL OCCASIONS SINCE THE LAST UNIT 3 | | REFUELING OUTAGE OVER 1 YEAR AGO, THE UNIT 3 INNER DOOR WAS OPEN | | (AND THUS ACCEPTABLE SECONDARY CONTAINMENT INTEGRITY NOT ESTABLISHED) | | FOR LONGER THAN 4 HOURS BUT LESS THAN 8 HOURS (1 WORK SHIFT) AND THAT | | THEY HAD NOT ENTERED TECH SPEC LCO A/S 3.7.C.2 ON THESE OCCASIONS. | | | | LICENSEE IS INVESTIGATING THE CAUSE AND DETERMINING CORRECTIVE ACTIONS. | | | | LICENSEE WILL INFORM THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28872 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: SEQUOYAH REGION: 2 |NOTIFICATION DATE: 05/31/95 | |UNIT: [ ] [2] [ ] STATE: TN |NOTIFICATION TIME: 19:39 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 05/31/95 | +------------------------------------------------+EVENT TIME: 18:09[EDT]| |NRC NOTIFIED BY: DENNIS DIMOPOULOS |LAST UPDATE DATE: 05/31/95 | |HQ OPS OFFICER: DICK JOLLIFFE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |DOUGLAS COLLINS 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 +------------------------------------------------------------------------------+ | - MAIN TURBINE TRIP / REACTOR TRIP DUE TO MAIN GENERATOR COOLING ALARM - | | | | AT 1809, UNIT 2 RECEIVED A MAIN GENERATOR COOLING FAILURE ALARM (HIGH | | GENERATOR STATOR COOLING WATER OUTLET TEMPERATURE). THE LICENSEE WAS | | PERFORMING A CHLORINATION OF THE RAW COOLING WATER SYSTEM, AND HAD BYPASSED | | THE TEMPERATURE CONTROL VALVE FOR THIS PROCESS. UPON RESTORING TO NORMAL, | | REVIEW OF THE PLANT COMPUTER DATA REVEALED A SPIKE IN GENERATOR STATOR | | COOLING WATER OUTLET TEMPERATURE. | | | | AFTER A 45 SECOND TIME DELAY, THE MAIN TURBINE AUTO-TRIPPED AND THE | | REACTOR AUTO-TRIPPED FROM 100% POWER. ALL CONTROL RODS INSERTED | | COMPLETELY. THE AUXILIARY FEEDWATER SYSTEM ACTUATED AS EXPECTED, AND THE | | PRESSURIZER PORV LIFTED AND RESEATED AS EXPECTED. STEAM IS BEING DUMPED TO | | THE MAIN CONDENSER. | | | | UNIT 2 IS STABLE IN MODE 3 (HOT STANDBY). | | | | THE LICENSEE IS IN THE PROCESS OF VERIFYING THE CALIBRATION OF THE | | TEMPERATURE SWITCH AND THE TEMPERATURE CONTROL VALVE CIRCUITRY. | | | | LICENSEE INFORMED THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 28873 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: FARLEY REGION: 2 |NOTIFICATION DATE: 06/01/95 | |UNIT: [ ] [2] [ ] STATE: AL |NOTIFICATION TIME: 02:26 [ET]| |RX TYPE: [1] W-3-LP,[2] W-3-LP |EVENT DATE: 06/01/95 | +------------------------------------------------+EVENT TIME: 00:58[CDT]| |NRC NOTIFIED BY: VAUDY HOLLY JR. |LAST UPDATE DATE: 06/01/95 | |HQ OPS OFFICER: LEIGH TROCINE +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |DOUGLAS COLLINS 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 15 POWER OPERATION | 0 HOT STANDBY | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | THE RUPTURE OF AN ELECTRO-HYDRAULIC CONTROL (EHC) LINE RESULTED IN A MANUAL | | TURBINE TRIP AND MANUAL REACTOR TRIP. | | | | A RUPTURE OF A 1/2-INCH TO 3/4-INCH DIAMETER EHC LINE OCCURRED WHILE THE | | UNIT WAS OPERATING AT APPROXIMATELY 30% POWER. (EHC FLUID IS USED IN THE | | CONTROL SYSTEMS FOR THE TURBINE AND THE STEAM GENERATOR FEEDWATER PUMPS.) | | THE EHC LINE SHEARED OFF AT A WELD WHERE THE LINE GOES INTO THE SUPPLY | | BLOCK FOR THE LOW PRESSURE GOVERNOR VALVE ON THE 'A' FEEDWATER PUMP (WHICH | | WAS SUPPLYING THE UNIT AT THE TIME OF THE EVENT). THE RUPTURED EHC LINE | | CAUSED A DROP IN EHC PRESSURE AND CAUSED OSCILLATIONS OF THE 'A' MAIN | | FEEDWATER PUMP. AS A RESULT, THE LICENSEE BEGAN DECREASING REACTOR POWER, | | STARTED THE THE MOTOR-DRIVEN AND TURBINE DRIVEN AUXILIARY FEEDWATER PUMPS, | | INITIATED A MANUAL TURBINE TRIP, AND INITIATED A MANUAL REACTOR TRIP WHEN | | THE UNIT WAS AT APPROXIMATELY 15% REACTOR POWER. | | | | THE LICENSEE DETERMINED THAT THERE MAY HAVE BEEN A FAULT IN THE FIRST OUT | | ANNUNCIATOR FOR A MANUAL REACTOR TRIP AND IS STILL INVESTIGATING WHETHER OR | | NOT AN AUTOMATIC REACTOR TRIP ON LOW-LOW STEAM GENERATOR WATER LEVEL MAY | | HAVE OCCURRED SIMULTANEOUSLY. (THE AUTOMATIC REACTOR TRIP ON A TURBINE | | TRIP OCCURS WHEN REACTOR POWER IS GREATER THAN OR EQUAL TO 35%.) FIRST OUT | | ANNUNCIATORS WERE NOT RECEIVED FOR EITHER A MANUAL REACTOR TRIP OR LOW-LOW | | STEAM GENERATOR LEVEL TRIP. THE FIRST OUT ANNUNCIATOR WAS A POWER RANGE | | NEGATIVE RATE TRIP WHEN THE CONTROL RODS WENT IN. THE LICENSEE BELIEVES | | THAT A MANUAL REACTOR TRIP OCCURRED FIRST BUT IS CURRENTLY VERIFYING THIS | | WITH COMPUTER LOGS. | | | | ALL CONTROL RODS FULLY INSERTED, AND ALL EMERGENCY CORE COOLING SYSTEMS AND | | ALL EMERGENCY DIESEL GENERATORS WERE OPERABLE AT THE TIME OF THE EVENT. | | CONDENSER VACUUM WAS ALSO MAINTAINED AT ALL TIMES. IN ADDITION, THERE WERE | | NO PROBLEMS WITH THE TRANSFERS OF POWER, AND NO POWER OPERATED RELIEF | | VALVES LIFTED. ALL SYSTEMS FUNCTIONED AS REQUIRED. | | | | FOLLOWING THE EVENT, THE LICENSEE RETURNED ALL SYSTEMS TO A STABLE | | CONDITION. THE LICENSEE'S POST-TRIP REVIEW IS CURRENTLY IN PROGRESS. | | | | THE LICENSEE WILL NOTIFY THE RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+