U.S. Nuclear Regulatory Commission Operations Center Event Reports For 09/26/94 - 09/27/94 ** EVENT NUMBERS ** 27825 27826 27827 +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 27825 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: ZION REGION: 3 |NOTIFICATION DATE: 09/26/94 | |UNIT: [1] [ ] [ ] STATE: IL |NOTIFICATION TIME: 15:54 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 09/26/94 | +------------------------------------------------+EVENT TIME: 11:03[CDT]| |NRC NOTIFIED BY: DRYER |LAST UPDATE DATE: 09/26/94 | |HQ OPS OFFICER: BOB STRANSKY +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |SHAFER 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 COMPONENT COOLING WATER PUMP DURING TESTING | | | | DURING PERFORMANCE OF CONTAINMENT ISOLATION PHASE B LOGIC TEST PT 10-3, THE | | "OC" COMPONENT COOLING WATER PUMP STARTED UNEXPECTEDLY. PRELIMINARY | | INVESTIGATION DETERMINED THAT A RELAY IN THE PUMP LOGIC HAD ACTUATED, | | CAUSING THE PUMP TO START. THE LICENSEE IS INVESTIGATING THE CAUSE OF THE | | RELAY ACTUATION. THE RI HAS BEEN INFORMED. | | | | * * * UPDATE 1826EDT ON 9/26/94 FROM KEITH DRYER TO S. SANDIN * * * | | "THE CAUSE OF THE AUTOSTART OF THE "OC" COMPONENT COOLING PUMP WAS FOUND TO | | BE A SHORTED CONTACT IN THE SI SEQUENCE TIMER WHICH ACTUATED THE RELAY | | CAUSING THE AUTOSTART. A SMALL 1/4" NUT FROM 1 OF 2 SCREWS FASTENING THE | | CONTACT TO THE SEQUENCER CAME LOOSE AND SHORTED THE CONTACT POINTS. ALL | | OTHER SEQUENCER TIMERS WERE VISUALLY INSPECTED FOR POSSIBLE SIMILAR LOOSE | | NUTS. NONE WERE FOUND. THE NUT AND SCREW HAVE BEEN RETRIEVED AND THE TIMER | | HAS BEEN DECLARED OPERABLE EXCEPT FOR THAT ONE CONTACT AND THE "OC" | | COMPONENT COOLING PUMP. REPAIRS WILL BE CONTINUED TOMORROW TO REPAIR THAT | | PARTICULAR CONTACT." | | | | SINCE THERE ARE FIVE COMPONENT COOLING PUMPS COMMON TO BOTH UNITS AND ONLY | | FOUR ARE REQUIRED PER TS FOR CURRENT PLANT OPERATION, NEITHER UNIT ENTERED | | AN LCO WITH "OC" COMPONENT COOLING PUMP INOPERABLE. THE LICENSEE WILL | | INFORM THE NRC RESIDENT INSPECTOR. NOTIFIED R3DO(SHAFER). | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 27826 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: COMANCHE PEAK REGION: 4 |NOTIFICATION DATE: 09/26/94 | |UNIT: [1] [ ] [ ] STATE: TX |NOTIFICATION TIME: 17:17 [ET]| |RX TYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 09/26/94 | +------------------------------------------------+EVENT TIME: 13:18[CDT]| |NRC NOTIFIED BY: ALLAN GLASS |LAST UPDATE DATE: 09/26/94 | |HQ OPS OFFICER: STEVE SANDIN +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |THOMAS WESTERMAN RDO | |APRE 50.72(b)(2)(vi) OFFSITE NOTIFICATION | | | | | | | | | | | | | | +-----+----------+-------+--------+--------------+--+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | OFFSITE NOTIFICATION TO STATE ENVIRONMENTAL AGENCY DUE TO SEWAGE SPILL. | | | | "AT 1335CDT, THE UNIT 1 CONTROL ROOM WAS INFORMED OF AN OFFSITE | | NOTIFICATION TO A TEXAS STATE AGENCY (TNRCC)." | | | | "THE NOTIFICATION TO THE STATE AGENCY WAS DUE TO A SEWAGE RELEASE TO THE | | ENVIRONMENT. THE DETAILS OF THE RELEASE ARE AS FOLLOWS: AT 0840CDT, A | | SEWAGE LIFT STATION WAS OVERFLOWING TO A STORM DRAIN. THE STORM DRAIN | | DISCHARGES TO A LOCAL RESERVOIR. THE RELEASE WAS STOPPED AT 0845CDT WHEN | | THE LIFT PUMP WAS RESTARTED. THE ESTIMATED AMOUNT OF DISCHARGE WAS 300 | | GALLONS." | | | | "THERE WAS NO RADIOACTIVITY INVOLVED IN THIS RELEASE" | | | | THE CAUSE OF THE RELEASE WAS DUE TO THE TRIP OF THE LIFT PUMP ON THERMAL | | OVERLOAD. THE SEWAGE WAS RELEASED TO THE ENVIRONMENT VIA THE STORM DRAIN | | SYSTEM TO OVERFLOW OF THE SAFE SHUTDOWN SETTLING POND TO SQUAW CREEK AND | | THE BRAZOS RIVER. THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR. | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |POWER REACTOR | |EVENT NUMBER: 27827 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |FACILITY: POINT BEACH REGION: 3 |NOTIFICATION DATE: 09/27/94 | |UNIT: [ ] [2] [ ] STATE: WI |NOTIFICATION TIME: 05:29 [ET]| |RX TYPE: [1] W-2-LP,[2] W-2-LP |EVENT DATE: 09/27/94 | +------------------------------------------------+EVENT TIME: 02:20[CDT]| |NRC NOTIFIED BY: KEVIN GROTE |LAST UPDATE DATE: 09/27/94 | |HQ OPS OFFICER: WILLIAM HUFFMAN +-----------------------------+ +------------------------------------------------+ NOTIFICATIONS | |EMERGENCY CLASS: NOT APPLICABLE +-----------------------------+ |10 CFR SECTION: |WAYNE SHAFER 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 N 0 REFUELING | 0 REFUELING | | | | | +-----+---------------------------------------------+--------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | LOSS OF OFFSITE POWER TO UNIT 2 WHILE PREPARING TO ELECTRICALLY CROSS-TIE | | TO UNIT 1. | | | | THE FOLLOWING IS THE TEXT OF A FACSIMILE PROVIDED BY THE LICENSEE REPORTING | | THIS EVENT: | | "AT 0220 ON 9/27/94, AN UNDERVOLTAGE SIGNAL ON THE PLANT'S UNIT 2 4160 VOLT | | SAFEGUARDS BUSES (2A05 AND 2A06) CAUSED TRIPPING OF THE NORMAL SUPPLY | | BREAKERS TO THESE BUSES. THIS RESULTED IN THE STARTING OF THE PLANT EDG'S | | (G01 AND G02) AND THEIR SUPPLYING POWER TO THE UNIT'S SAFEGUARDS BUSES. | | BELOW IS A SUMMARY OF THE EVENT AND PLANT CONDITIONS: | | | | WITH UNIT 2 IN A REFUELING SHUTDOWN (RCS AT APPROXIMATELY 110 DEGREES; | | ATMOSPHERIC PRESSURE; AND PRESSURIZER LEVEL AT 6%), AN ELECTRICAL | | MAINTENANCE PROCEDURE WAS IN PROGRESS TO PERFORM MAINTENANCE ON THE 2-X04 | | TRANSFORMER. THE PROCEDURE HAD THE UNIT 2 ELECTRICAL BUSES SUPPLIED BY THE | | GAS TURBINE (G05) AND ISOLATED FROM SITE POWER. WHILE IN THIS LINEUP, AN | | UNDERVOLTAGE SIGNAL WAS RECEIVED ON THE UNIT'S 4160 VOLT BUSES RESULTING IN | | THE BUSES BEING PICKED UP BY THE EDG'S AS NOTED ABOVE. | | | | AS A RESULT OF THE POWER INTERRUPTION, THE OPERATING RESIDUAL HEAT REMOVAL | | PUMP (2F-10A) WAS LOST. IT WAS RESTARTED APPROXIMATELY 2 MINUTES LATER | | (SUPPLIED THROUGH THE EDG). A TEMPERATURE INCREASE OF APPROXIMATELY 6 øF | | WAS NOTED WHILE THE RHR PUMP WAS SECURED. | | | | OFFSITE POWER WAS RESTORED TO UNIT 2 PER THE MAINTENANCE PROCEDURE AND THE | | EDG'S WERE SECURED IN ACCORDANCE WITH NORMAL OPERATING PROCEDURES. | | | | AT THIS TIME, THE EXACT CAUSE OF THE UNDERVOLTAGE SIGNAL IS NOT KNOWN." | | | | THE LICENSEE STATES THAT THEY WERE IN THE PROCESS OF ISOLATING THEIR NORMAL | | OFFSITE POWER SUPPLY AUXILIARY TRANSFORMER (2X04) FOR THE PURPOSE OF | | CHANGING THE OUTPUT TAPS. BECAUSE OF THE CURRENT OUTPUT VOLTAGE OF THIS | | TRANSFORMER, IT DOES NOT MATCH THE BUS VOLTAGES ON THE UNIT 1 SIDE. TO | | CROSS-TIE THE UNITS, THE BUS VOLTAGE ON THE UNIT 2 SIDE HAS TO BE | | INCREASED. THE LICENSEE WAS USING AN ONSITE GAS TURBINE TO ASSUME ALL PLANT | | LOADS AND INCREASE THE UNIT 2 BUS VOLTAGES IN ORDER TO PARALLEL WITH UNIT 1 | | AND THEN CROSS-TIE. | | | | FOR UNKNOWN REASONS, THE SAFEGUARDS BUSES SHED THEIR LOADS ON UNDERVOLTAGE | | WHILE THE BUS VOLTAGE WAS ACTUALLY BEING INCREASED. AT THE TIME, ALL PLANT | | LOADS WERE BEING SUPPLIED BY THE SAFEGUARDS BUSES FED BY THE GAS TURBINE. | | THE EDG'S STARTED AND SUPPLIED THE BUSES AS DESIGNED. | | | | UNIT 2 REMAINED ON EDG POWER FOR ABOUT 1.5 HOURS WHILE THE LICENSEE WAS | | INVESTIGATING THE CAUSE OF THE UNDERVOLTAGE TRIPS. OFFSITE POWER WAS | | AVAILABLE FROM UNIT 1 AT ANY TIME AFTER THIS EVENT OCCURRED SHOULD IT HAVE | | BEEN NEEDED. UNIT 2 POWER FROM OFFSITE VIA A UNIT 1 CROSS-TIE WAS | | RE-ESTABLISHED AT 0420 CDT. THE CAUSE OF THE LOAD SHED IS STILL UNDER | | INVESTIGATION. THE LICENSEE STATES THAT THIS CONDITION DID NOT PLACE THEM | | INTO ANY EMERGENCY CLASSIFICATION PER THEIR EPIP'S. | | | | THE NRC RESIDENT INSPECTOR HAS BEEN NOTIFIED. | +------------------------------------------------------------------------------+