Event Notification Report for June 11, 2003
U.S. Nuclear Regulatory Commission Operations Center Event Reports For 06/10/2003 - 06/11/2003 ** EVENT NUMBERS ** 39855 39904 39906 39911 39912 39915 39916 39917 !!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!!! +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 39855 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: COOK REGION: 3 |NOTIFICATION DATE: 05/18/2003| | UNIT: [] [2] [] STATE: MI |NOTIFICATION TIME: 04:27[EDT]| | RXTYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 05/17/2003| +------------------------------------------------+EVENT TIME: 22:05[EDT]| | NRC NOTIFIED BY: BRIAN BATES |LAST UPDATE DATE: 06/10/2003| | HQ OPS OFFICER: ARLON COSTA +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: NON EMERGENCY |SONIA BURGESS R3 | |10 CFR SECTION: |MICHAEL CASE NRR | |ADEG 50.72(b)(3)(ii)(A) DEGRADED CONDITION | | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | |2 N N 0 Refueling Shutdow|0 Refueling Shutdow| | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | DEGRADED CONDITION DUE TO CRACK INDICATIONS ON VESSEL HEAD | | | | "At 18:00 on 5/15/03, craze cracking indications were found on a Reactor | | Pressure Vessel Head Penetration. At 22:05 on 5/17/03, it was determined | | that this condition was reportable as a prompt eight-hour report under 10 | | CFR 50.72(b)(3)(ii)(A). | | | | "During the Unit 2 reactor head inspection, five small, shallow indications | | were found on the inside diameter of penetration #74. The indications are | | closely spaced and are approximately 3/8 inch below the J-groove weld | | region. Initial calculations showed a crack depth of 0.117 inches. All of | | the indications are bounded within an area that is one inch wide by 2.6 | | inches high. There was no through-wall leakage and the reactor coolant | | pressure boundary remains intact. | | | | "These indications were previously identified during the last refueling | | outage in February 2002. They were evaluated as acceptable to leave in | | service for a full cycle at that time, and they have not shown any | | significant growth since then. | | | | "The industry guidance on projected flaw growth rates has been revised since | | these indications were discovered in 2002. As a result, the new projections | | for these indications result in less than a full fuel cycle before reaching | | the limit for remaining in service. Therefore, repairs will be needed. | | Current plans are to perform an excavation of the affected area, under | | existing code guidance." | | | | The NRC Resident Inspector has been notified. | | | | * * * UPDATE AT 0811 EDT ON 6/10/03 FROM HACKMAN TO CROUCH * * * | | | | The following information was obtained from the licensee via facsimile: | | | | "Following evaluation of the condition reported in EN# 39855, it has been | | determined that the craze cracking indications in penetration 74 of the Unit | | 2 Reactor Pressure Vessel Head do not represent a seriously degraded | | principal safety barrier of the nuclear power plant. | | | | "As stated in the initial ENS report, the flaw was on the inside diameter of | | the penetration approximately 3/8 inch below the J-groove weld. The flaw | | evaluation concluded that no growth occurred from the last inspection and at | | least one effective full power year of operation would pass prior to the | | crack growing to an unacceptable depth (75 percent through wall). | | Accordingly, Cook Nuclear Plant withdraws EN# 39855. | | | | "Additionally, as part of the withdrawal, a correction to the information | | contained in EN# 39855 is being made. EN# 39855 stated that repairs were | | required this refueling outage due to changes in the industry guidance on | | projected flaw growth rates. The flaw evaluation performed for the 2002 | | refueling outage was based on growth charts in the flaw evaluation handbook | | (WCAP 14118, Rev 5) using the depth of the cracking without considering the | | length. The flaw evaluation for this outage was conservatively calculated | | considering both depth and length, which resulted in less than a cycle of | | operation prior to growing 75 percent through wall. The decision to repair | | the penetration allows Unit 2 to operate for a full fuel cycle. There was | | no change in industry guidance that compelled a repair for this outage." | | | | | | The crack was repaired during the current refueling outage. The longest | | crack length identified was 2.1 inches with a depth of .117 inches in the | | penetration inside diameter of 2.75 inches. Wall thickness of penetration | | is nominally 0.625 inches. | | | | The NRC Resident Inspector was notified of the retraction by the licensee. | | | | Notified R3DO (Hills) and NRR EO (Reis). | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |General Information or Other |Event Number: 39904 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | REP ORG: NEW MEXICO RAD CONTROL PROGRAM |NOTIFICATION DATE: 06/05/2003| |LICENSEE: SPECTRATEK SERVICES |NOTIFICATION TIME: 13:15[EDT]| | CITY: ALBUQUERQUE REGION: 4 |EVENT DATE: 06/05/2003| | COUNTY: STATE: NM |EVENT TIME: [MDT]| |LICENSE#: TA-172-21 AGREEMENT: Y |LAST UPDATE DATE: 06/07/2003| | DOCKET: |+----------------------------+ | |PERSON ORGANIZATION | | |DAVID LOVELESS R4 | | |PATRICIA HOLAHAN NMSS | +------------------------------------------------+STEWART BAILEY DOE | | NRC NOTIFIED BY: BILL FLOYD |PO SCOTT BAUMGARTNER DOT | | HQ OPS OFFICER: STEVE SANDIN | | +------------------------------------------------+ | |EMERGENCY CLASS: NON EMERGENCY | | |10 CFR SECTION: | | |NAGR AGREEMENT STATE | | | | | | | | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AGREEMENT STATE REPORT INVOLVING A MISSING WELL LOGGING SOURCE SHIPMENT | | | | On 6/5/03, the NM Rad Control Program Office was notified by SpectraTek that | | one of four boxes in a shipment of well logging sources sent from SpectraTek | | in Albuquerque via FEDEX on 6/2/03, airbill #791397943907, to Elite Air | | Freight in Houston, TX was missing. The missing box contains a 40 | | millicurie Scandium-46 source. The shipment which is enroute to Nigeria is | | currently being held in Houston pending resolution of the missing source | | issue. Elite Air Freight contacted FEDEX who believes that the package has | | been located in the Houston area. NM State Report #NM-03-04. | | | | * * * UPDATE 1342EDT 6/6/03 FROM MIKE BREWER (SPECTRATEK) TO S. SANDIN | | | | The missing box containing the 40 millicurie Scandium-46 source was located | | and delivered to Elite Air Freight in Houston, TX the morning of 6/6/03. | | Notified R4DO(Loveless), NMSS(Broaddus), DOE(Bailey), and EPA | | RegionVI(Hammack). | | | | * * * UPDATE 1540EDT 6/6/03 FROM PAUL PATRICK (FEDEX) TO S. SANDIN | | | | Due to an administrative oversight, the wrong airbill was updated showing | | delivery. FEDEX is still investigating and attempting to locate this | | shipment. Notified R4DO(Loveless), NMSS(Broaddus), DOE(Bailey), and EPA | | RegionVI(Hammack). | | | | * * * UPDATE 1730EDT 6/7/03 FROM MARVIN SUDDUTH TO GERRY WAIG * * * | | | | The missing package was located at approximately 1645EDT at the | | Houston-Hobby Satellite facility in the Dangerous Goods area with no | | indication of damage or tampering. A FEDEX security specialist is currently | | escorting the package to the main FEDEX facility for safe storage over the | | weekend. FEDEX will make arrangements to have a management representive | | deliver the package to the receipt on Monday morning and will inform | | SpectraTek. Notified R4(Loveless, Maier ), R2(Landis), NMSS(Holahan, | | Broaddus, Miller), EDO(Kane), OSTP(Lothaus), DOE(Turner), EPA | | RegionVI(Hammack), and DHS(Svenningsen). | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |General Information or Other |Event Number: 39906 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | REP ORG: OK DEQ RAD MANAGEMENT |NOTIFICATION DATE: 06/05/2003| |LICENSEE: ABIOTIC ENTERPRISES |NOTIFICATION TIME: 16:50[EDT]| | CITY: OKLAHOMA CITY REGION: 4 |EVENT DATE: 06/03/2003| | COUNTY: STATE: OK |EVENT TIME: [CDT]| |LICENSE#: OK-27607-01 AGREEMENT: Y |LAST UPDATE DATE: 06/05/2003| | DOCKET: |+----------------------------+ | |PERSON ORGANIZATION | | |DAVID LOVELESS R4 | | |PATRICIA HOLAHAN NMSS | +------------------------------------------------+ | | NRC NOTIFIED BY: MIKE BRODERICK | | | HQ OPS OFFICER: STEVE SANDIN | | +------------------------------------------------+ | |EMERGENCY CLASS: NON EMERGENCY | | |10 CFR SECTION: | | |NAGR AGREEMENT STATE | | | | | | | | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | TWO TROXLER MOISTURE DENSITY GAUGES DISCOVERED ABANDONED | | | | On 6/3/03 during a special inspection for non-payment of license fees, state | | inspectors found the Abiotic Enterprises facility located at 2320 South | | Portland in Oklahoma City closed and, by all appearances, defunct. The | | landlord who is located in the same structure said that his tenant, i.e., | | Abiotic Enterprises, was five (5) months in arrears on rent and that he had | | not seen any activity for more than a month. The state inspectors entered | | the business with the assistance of the landlord and found two (2) Troxler | | Moisture Density Gauges, a model 3430 S/N 29405 and a model 3440 S/N 29452, | | inside an unlocked caged area. The cases containing the gauges and the | | source rods were also found unlocked. Oklahoma has revoked Adiotic | | Enterprises license subject to administrative appeal. On 6/4/03, both | | Troxlers were impounded by the state and are currently in storage within the | | OK rad program vault. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 39911 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: ROBINSON REGION: 2 |NOTIFICATION DATE: 06/10/2003| | UNIT: [2] [] [] STATE: SC |NOTIFICATION TIME: 11:31[EDT]| | RXTYPE: [2] W-3-LP |EVENT DATE: 06/05/2003| +------------------------------------------------+EVENT TIME: 19:49[EDT]| | NRC NOTIFIED BY: CURTIS CASTELL |LAST UPDATE DATE: 06/10/2003| | HQ OPS OFFICER: HOWIE CROUCH +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: NON EMERGENCY |KERRY LANDIS R2 | |10 CFR SECTION: | | |AINC 50.72(b)(3)(v)(C) POT UNCNTRL RAD REL | | |AIND 50.72(b)(3)(v)(D) ACCIDENT MITIGATION | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ |2 N Y 100 Power Operation |100 Power Operation | | | | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | FAILURE IN RADIOACTIVE GAS RELEASE MONITORING EQUIPMENT DEGRADES ACCIDENT | | MITIGATION SYSTEM | | | | The following information was received from the licensee via facsimile: | | | | "At approximately 19:49 hours [EDT] on June 5, 2003, during a source check | | of containment radiation monitor R-11 with containment pressure relief in | | progress, the containment pressure relief isolation valves, V12-10 and | | V12-11, would not close automatically. The valves were closed by use of the | | control switch in the control room to stop the pressure relief of the | | containment at the time of the source check failure. The source check | | should have caused the valves to close automatically by the initiation of a | | containment ventilation isolation signal. The penetration was isolated at | | 20:47 hours by the use of closed and de-activated automatic isolation valve; | | specifically valve V12-10 was closed and de-activated, in accordance with | | Technical Specifications Limiting Conditions for Operation (LCO) 3.6.3, | | Containment Isolation Valves, Required Action B.1. Subsequent evaluation, | | during review of the condition report for this failure, has determined that | | the failure, which was caused by a faulty control switch, would have | | prevented the automatic closure of these valves as required for a | | containment isolation or a containment high radiation signal. Therefore, | | this event is being reported as a condition that alone could have prevented | | the fulfillment of a safety function of a structure, system, or component | | that is needed to control the release of radioactivity or mitigate the | | consequences of accident, in accordance with 10 CFR 50.72(b)(3)(v)(C) and | | (D). The control switch was repaired at approximately 14:13 hours on June | | 6, 2003, and the system was restored to operable status at that time. A | | planned and monitored gaseous release from the containment was in progress | | at the time of this event using the containment pressure relief system. No | | release limits were exceeded. If plant conditions had required isolation of | | the penetration, alarms and indications in the Control Room would have | | alerted the operators to the condition and the applicable operating | | procedures direct the operators to manually isolate the penetration. | | | | "(The following information is system description information for the | | Containment Pressure and Vacuum Relief System copied from the H. B. Robinson | | Steam Electric Plant, Unit No. 2, Updated Final Safety Analysis Report): | | | | "Normal power operation is conducted with the closed containment building at | | essentially atmospheric pressure. The Containment Pressure and Vacuum Relief | | System is provided to control variations in containment pressure with | | respect to atmospheric pressure. These variations are due to changes in | | atmospheric pressure and leakage from the Instrument Air and Penetration | | Pressurization Systems. The containment pressure and vacuum relief system | | includes separate 6 inch lines penetrating the containment, each equipped | | with two quick-closing, tight-seating, 125 psi air operated butterfly | | valves, one inside and one outside containment. These valves are designed | | to fail closed on loss of control signal or control air, and are closed | | during normal plant operation, except as required for pressure control. | | | | "The butterfly valves are protected by debris screens, located inside | | containment and attached to the inboard pressure and vacuum relief valves, | | which will ensure that airborne debris will not interfere with their tight | | closure. The pressure relief line discharges to the plant vent through a | | HEPA filter and charcoal filters. These filters are provided for removal of | | particulate and halogen radioactivity from the vented air. Operation of the | | pressure and vacuum relief lines is manually controlled by the plant | | operator. A narrow range pressure transmitter continuously indicates | | containment pressure in the Control Room. Separate high and low pressure | | alarms are actuated by this transmitter to alert the operator to | | overpressure and vacuum conditions. These alarms are tentatively set for | | actuation at plus and minus 0.3 psig. Vacuum relief can be accomplished | | without regard to atmospheric conditions. In the event of pressure buildup, | | the operator will be guided by atmospheric conditions, and by the | | containment particulate and radiogas monitor in relieving the overpressure. | | Manual operation of both these lines is overridden by automatic containment | | isolation and containment high radioactivity signals." | | | | The licensee notified the NRC Resident Inspector. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 39912 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: PILGRIM REGION: 1 |NOTIFICATION DATE: 06/10/2003| | UNIT: [1] [] [] STATE: MA |NOTIFICATION TIME: 12:36[EDT]| | RXTYPE: [1] GE-3 |EVENT DATE: 06/10/2003| +------------------------------------------------+EVENT TIME: 09:30[EDT]| | NRC NOTIFIED BY: FRANK CLIFFORD |LAST UPDATE DATE: 06/10/2003| | HQ OPS OFFICER: STEVE SANDIN +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: NON EMERGENCY |CHRISTOPHER CAHILL R1 | |10 CFR SECTION: | | |ACOM 50.72(b)(3)(xiii) LOSS COMM/ASMT/RESPONSE| | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | INABILITY TO ACTIVATE EMERGENCY SIRENS DUE TO EQUIPMENT FAILURE | | | | "On June 10, 2003 at 0930 hours, the control room was notified that all 112 | | Prompt Alert and Notification System (PANS) sirens were inoperable by | | maintenance personnel. All necessary notifications to local towns and MEMA | | (Massachusetts Emergency Management Agency) have been made. A backup plan | | (route altering) is in place in the event of an emergency at Pilgrim | | station. It was determined that one of the 112 sirens was transmitting a | | continuous radio signal to the remaining sirens, preventing actuation. The | | faulty siren was isolated from the system at 1040 [hours], and the remaining | | 111 sirens are now operational." | | | | The licensee informed both state and local agencies and the NRC resident | | inspector. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 39915 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: MCGUIRE REGION: 2 |NOTIFICATION DATE: 06/10/2003| | UNIT: [1] [2] [] STATE: NC |NOTIFICATION TIME: 17:50[EDT]| | RXTYPE: [1] W-4-LP,[2] W-4-LP |EVENT DATE: 06/10/2003| +------------------------------------------------+EVENT TIME: 12:11[EDT]| | NRC NOTIFIED BY: RANDY TRACEY |LAST UPDATE DATE: 06/10/2003| | HQ OPS OFFICER: STEVE SANDIN +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: NON EMERGENCY |MARK LESSER R2 | |10 CFR SECTION: | | |AUNA 50.72(b)(3)(ii)(B) UNANALYZED CONDITION | | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | INADEQUATE I & C CABLE SEPARATION DISCOVERED DURING APPENDIX "R" REVIEW | | | | "McGuire has identified that Unit 1 and Unit 2 electrical cables associated | | with redundant safe shutdown trains do not meet the separation criteria of | | Appendix R. Specifically, cables for all four channels of a Unit's Reactor | | Protection System (RPS) are routed together through the respective Unit's | | ETA Switchgear Room. This room has no fire detection or suppression | | capabilities in the area containing the cables. Consequently, in the event | | of a postulated Appendix R fire in the ETA Switchgear Room, all four | | channels of the respective Unit's RPS could be susceptible to fire damage. | | Upon discovery of this condition, a fire watch was established in the Unit 1 | | and Unit 2 ETA Switchgear Rooms. | | | | "McGuire has not yet determined whether this condition would result in the | | loss of a safety function significantly degrading plant safety. However, | | since this condition is similar to an example provided in NUREG 1022 Section | | 3.2.4, McGuire is conservatively reporting this as an unanalyzed condition | | significantly degrading plant safety." | | | | The licensee informed the NRC resident inspector. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 39916 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: CALLAWAY REGION: 4 |NOTIFICATION DATE: 06/10/2003| | UNIT: [1] [] [] STATE: MO |NOTIFICATION TIME: 22:28[EDT]| | RXTYPE: [1] W-4-LP |EVENT DATE: 06/10/2003| +------------------------------------------------+EVENT TIME: 17:20[CDT]| | NRC NOTIFIED BY: J. R. WEEKLEY |LAST UPDATE DATE: 06/10/2003| | HQ OPS OFFICER: ARLON COSTA +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: NON EMERGENCY |DAVID GRAVES R4 | |10 CFR SECTION: | | |ACOM 50.72(b)(3)(xiii) LOSS COMM/ASMT/RESPONSE| | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |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 +------------------------------------------------------------------------------+ | LOSS OF OFFSITE EMERGENCY RESPONSE CAPABILITY DUE TO DAMAGED POWER LINE | | | | Power to the Emergency Operations Facility (EOF) was unavailable for | | approximately two and a half hours due to a severe thunderstorm and a downed | | power line feeding the facility. An Emergency Diesel Generator (EDG) is | | running, supplying power to the EOF. | | | | The licensee notified the NRC Resident Inspector. | | | | *** UPDATE AT 2311 EDT ON 6/10/03 FROM J.R. WEEKLEY TO A. COSTA *** | | | | The downed power line to the EOF has been repaired and electricity to the | | facility has been restored. The licensee terminated use of the EDG. | | | | The NRC Resident Inspector will be notified by the licensee. | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ |Power Reactor |Event Number: 39917 | +------------------------------------------------------------------------------+ +------------------------------------------------------------------------------+ | FACILITY: SAINT LUCIE REGION: 2 |NOTIFICATION DATE: 06/11/2003| | UNIT: [] [2] [] STATE: FL |NOTIFICATION TIME: 02:26[EDT]| | RXTYPE: [1] CE,[2] CE |EVENT DATE: 06/11/2003| +------------------------------------------------+EVENT TIME: 01:30[EDT]| | NRC NOTIFIED BY: JOE HESSLING |LAST UPDATE DATE: 06/11/2003| | HQ OPS OFFICER: JOHN MacKINNON +-----------------------------+ +------------------------------------------------+PERSON ORGANIZATION | |EMERGENCY CLASS: NON EMERGENCY |MARK LESSER R2 | |10 CFR SECTION: | | |ARPS 50.72(b)(2)(iv)(B) RPS ACTUATION - CRITICA| | | | | | | | | | | +-----+----------+-------+--------+-----------------+--------+-----------------+ |UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE | +-----+----------+-------+--------+-----------------+--------+-----------------+ | | | |2 A/R Y 22 Power Operation |0 Hot Standby | | | | +------------------------------------------------------------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | AUTOMATIC TURBINE TRIP/REACTOR TRIP DUE TO HIGH HIGH STEAM GENERATOR WATER | | LEVEL | | | | "On 06/11/03, Unit 2 Reactor tripped via Turbine Trip due to high-high | | Steam Generator level. All Control Rods fully inserted. Unit stable in | | Mode 3 (Hot Standby). Auxiliary Feedwater system was manually started and | | currently maintaining steam generator levels. Investigation is in progress | | to determine initial cause for loss of feed to the 2A Steam Generator from | | its associated low power feedwater regulating valve." | | | | | | Coming out of a refueling outage reactor power was at 30% when it was | | noticed that main feedwater regulating valves were oscillating. Reactor | | power was reduced to 20% and the low power feedwater regulating valves were | | placed in service so testing of the main feedwater regulating valves could | | be performed. During testing of the main feedwater regulating valves at | | approximately 22% reactor power low power feedwater flow to the 2A Steam | | Generator ceased. The duel indications for the low power feedwater | | regulating valve indicated that the valve was open but Steam Generator 2A | | water level was decreasing. Since main feedwater regulating valve was being | | tested the 100% bypass low power feedwater regulating valve was opened. | | Steam Generator water level began to increase rapidly so the valve was | | closed. 2A Steam Generator level began to decrease so the 100% bypass low | | power feedwater regulating valve was reopened. This time 2A Steam Generator | | water level increase above 88% narrow range which caused an automatic | | turbine trip. Since reactor power was greater than 15% the reactor | | automatically tripped due to the turbine trip. All rods fully inserted into | | the core. Since the reactor core had very little decay heat the main steam | | isolation valves were closed and both motor driven auxiliary feedwater pumps | | were manually started. Motor Driven Auxiliary Feedwater Pumps and Steam | | Generator PORVs operation is maintaining the plant in a Hot Standby | | condition. All emergency core cooling systems are fully operable and the | | emergency diesel generators are fully operable if needed. The electrical | | grid is stable. The licensee believes that the stem of the low power | | feedwater regulating valve separated from the valve which in turn caused the | | valve to close while still having duel indication that the low power | | feedwater valve was open. | | | | The NRC Resident Inspector was notified of this event by the licensee. | +------------------------------------------------------------------------------+
Page Last Reviewed/Updated Thursday, March 25, 2021
Page Last Reviewed/Updated Thursday, March 25, 2021