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 Entered dateSiteRegionReactor typeEvent description
ENS 5622114 November 2022 13:05:00OconeeNRC Region 2B&W-L-LPThe following information was provided by the licensee via email: During a scheduled refueling outage, a walkdown inside containment discovered a small amount of boron on the 1B2 Reactor Coolant Pump (RCP) lower bearing temperature instrument. At 0730 EST on November 14, 2022, with Unit 1 in Mode 6, disassembly of the instrument indicated the source of the boron was from a leak in the thermowell. The thermowell is considered part of the reactor coolant system pressure boundary and as such the condition is reportable. Repairs for the condition are in progress. This event is being reported as an eight-hour non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 561971 November 2022 16:56:00OconeeNRC Region 2B&W-L-LPThe following information was provided by the licensee via email: At 1433 EDT on November 1, 2022, it was determined that a single relevant indication in the RCS pressure boundary did not meet the acceptance criteria under ASME, Section XI IWB-3514-2. 'Allowable Planar Flaws.' The condition will be resolved prior to plant startup. This event is being reported as an eight-hour non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5619031 October 2022 00:40:00HarrisNRC Region 2Westinghouse PWR 3-LoopThe following information was provided by the licensee via email: At 2057 Eastern Daylight Time (EDT), with Unit 1 in Mode 3 at 0 percent power, an actuation of the Auxiliary Feedwater (AFW) System occurred during an attempt to start the 'B' Main Feed Pump. The reason for the AFW system auto-start was due to the 'A' electrical bus being under clearance and the 'B' Main Feed Pump not starting, resulting in a valid actuation signal for loss of both Main Feedwater pumps. The 'A' and 'B' motor-driven AFW (MDAFW) pumps were running prior to the attempted start of the B Main Feedwater pump and continued to run. The MDAFW Flow Control Valves (FCVs) went full open automatically as designed when the MDAFW actuation signal was received. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the AFW System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5618930 October 2022 09:43:00HarrisNRC Region 2Westinghouse PWR 3-LoopThe following information was provided by the licensee via email: At 0653 Eastern Daylight Time (EDT), with Unit 1 in Mode 1, at 16 percent power, an automatic reactor trip occurred due to an under-voltage condition on the 'A' reactor coolant pump (RCP) and the 'C' RCP. Power was lost from the 'A' auxiliary bus while performing an operating procedure to transfer power from the 'A' start-up transformer to the 'A' unit auxiliary transformer. Operations responded and stabilized the plant. Decay heat is being removed by the main steam system to the atmosphere using the steam generator power-operated relief valves. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported per 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the auxiliary feedwater system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5618628 October 2022 02:24:00HarrisNRC Region 2Westinghouse PWR 3-LoopThe following information was provided by the licensee via email: At 2050 EDT (on October 27, 2022), with Unit 1 in Mode 3, it was discovered that all auxiliary feedwater pumps were simultaneously inoperable and the capability to supply the 'B' steam generator was not maintained; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The function of the auxiliary feedwater pumps to supply the 'A' steam generator and 'C' steam generator was maintained. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5617724 October 2022 11:40:00CatawbaNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: On 10/24/2022 at 0857 EDT, with Unit 2 in Mode 1 at 7 percent power, the reactor was manually tripped due to a 2B train main feedwater pump trip. The trip was not complex, with all systems responding normally post-trip. The auxiliary feedwater (AFW) system started automatically as expected. Operations responded and stabilized the plant. Decay heat is being removed by the steam generators and discharging to the condenser. Unit 1 is not affected. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The automatic start of the auxiliary feedwater system is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5617220 October 2022 20:24:00CatawbaNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: At 1446 EDT on October 20, 2022, an individual was transported offsite for treatment at an offsite medical facility. Due to the nature of the medical condition, the individual was not thoroughly surveyed prior to being transported offsite. Follow-up surveys performed by radiation protection technicians identified no contamination of the worker or of the ambulance and response personnel. This is an eight-hour notification, non-emergency for the transportation of a contaminated person offsite. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xii). The NRC Resident Inspector has been notified.
ENS 5616515 October 2022 15:46:00CatawbaNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: On 10/15/2022 at 1159 (EDT), during the Catawba Nuclear Station Unit 2 refueling outage, it was determined that the results of a planned surface examination Liquid Penetrant test (PT) performed on a previous overlay repair on nozzle number 74 of the reactor vessel closure head (RVCH) did not meet applicable acceptance standards. The examination was being performed to meet the requirements of Relief Request RA-21-0144, 'Proposed Alternative to Use Reactor Vessel Head Penetration Embedded Flaw Repair for Life of Plant'. The penetration required repairs for the discovered indications. The repairs have been completed in accordance with the ASME Code of Record prior to returning the vessel head to service. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The original indication that led to the overlay repair was discovered in April 2021, during ultrasonic testing and reported to the NRC and assigned EN55201.
ENS 561384 October 2022 10:27:00BrunswickNRC Region 2GE-4The following information was provided by the licensee via email: This 60-day optional telephone notification is being made in lieu of an LER submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for invalid actuations of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 0628 Eastern Daylight Time (EDT) on August 6, 2022, an invalid actuation of group 6 Primary Containment Isolation Valves (PCIVs) (i.e., containment atmospheric control/monitoring and post accident sampling isolation valves) occurred. The group 6 isolation signal resulted from the reactor building ventilation radiation monitor `A' channel exceeding the setpoint value. This condition recurred at approximately 1305 EDT on August 12, 2022. In both instances, the `B' channel, located in the same plenum, remained steady and below the setpoint value through the entire event. This, along with readings made by radiation protection technicians, confirmed that there were no actual high radiation conditions in the reactor building exhaust in either instance. Following each invalid actuation, upon returning unit 2 reactor building ventilation to service, the `A' channel readings returned to be consistent with the `B' channel. It was determined that these invalid actuations likely resulted from degradation of circuit components associated with the radiation monitor. The `A' channel radiation monitor was replaced on September 22, 2022. During these two events, the PCIVs functioned successfully and the actuations were complete. The actuations were not initiated in response to actual plant conditions, they were not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, these events have been determined to be invalid actuations. These events did not result in any adverse impact to the health and safety of the public.
ENS 5607528 August 2022 07:08:00HarrisNRC Region 2Westinghouse PWR 3-LoopThe following information was provided by the licensee via email: (On 8/28/2022) at 0329 Eastern Daylight Time (EDT), with Unit 1 in Mode 1 at 100% power, the reactor was manually tripped due to a 'B' train main feedwater pump trip. The trip was not complex with all systems responding normally post-trip. The auxiliary feedwater (AFW) system started automatically as expected. Operations responded and stabilized the plant. Steam generator levels are being maintained by AFW through the AFW flow control valves. Decay heat is being removed by using the steam generator power-operated relief valves. The reason for the 'B' train main feedwater pump trip is under investigation. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported per 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the auxiliary feedwater system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The cause of the 'B' train main feedwater pump trip is suspected to be the result of an electrical transient due to the alarms that the operators received. In addition, the 'A' train main feedwater pump also tripped subsequent to the reactor trip and that cause is still under investigation.
ENS 5601625 July 2022 13:30:00BrunswickNRC Region 2GE-4The following information was provided by the licensee via email: At 1058 Eastern Daylight Time (EDT) on July 25, 2022, it was determined that a non-licensed supervisor failed a test specified by the FFD testing program for the substance alcohol. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified.
ENS 5599715 July 2022 23:41:00BrunswickNRC Region 2GE-4The following information was provided by the licensee via email: At 2020 Eastern Daylight Time (EDT) on July 15, 2022, the HPCI System was declared inoperable. Therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The Reactor Core Isolation Cooling (RCIC) System and Automatic Depressurization System (ADS) were operable during this time. HPCI availability was restored at 2023. Additional investigation is in-progress. There was no impact on the health and safety of the public or plant personnel. Unit 2 is not affected by this event. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: HPCI is considered inoperable but available at this time, resulting in a 14-day Shutdown LCO (Limiting Condition for Operation), due to the HPCI inoperability.
ENS 5595522 June 2022 02:26:00McGuireNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: At 2240 on 06/21/2022, it was discovered that both required trains of Control Room Ventilation and Control Area Chilled Water System were simultaneously inoperable; therefore, this condition is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(v)(d). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The 'B' train was restored at 2315.
ENS 558887 May 2022 04:37:00OconeeNRC Region 2B&W-L-LPThe following information was provided by the licensee via fax: At 2310 EDT on May 6, 2022, with Unit 3 in Mode 3, an actuation of the Emergency Feedwater (EFW) System occurred while entering a planned refueling outage. The reason for the EFW auto-start was a loss of all Main Feedwater (MFDW) Pumps which occurred when the 3A MFDW Pump tripped on steam generator (SG) overfill protection due to high level in the 3B SG. The high level in the 3B SG occurred when a Startup Feedwater Control Valve (3FDW-44) malfunctioned, resulting in excessive feedwater flow to the 3B SG. Investigation and repairs are in progress. Units 1 and 2 were not affected. This event is being reported as an 8-hr non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as a valid actuation of the EFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5586829 April 2022 07:49:00HarrisNRC Region 2Westinghouse PWR 3-LoopThe following information was provided by the licensee via email: At 0405 Eastern Daylight Time (EDT), with Unit 1 in Mode 1 at 100 percent power, the reactor was manually tripped due to degrading condenser vacuum. The trip was not complex, with all systems responding normally post-trip. The Auxiliary Feedwater System started automatically as expected. Operations responded and stabilized the plant. Decay heat is being removed by the Main Steam System to the main condenser using the turbine bypass valves. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported per 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the Auxiliary Feedwater System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: No Tech Spec limits were exceeded. Offsite power is available. The suspected cause for the loss of condenser vacuum is when performing the scheduled monthly swap of condenser vacuum pumps, a suction valve failed to shut.
ENS 5585926 April 2022 13:13:00BrunswickNRC Region 2GE-4The following information was provided by the licensee via fax or email: This 60-day telephone notification is being made in lieu of an LER submittal per 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for invalid actuations of systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 0040 Eastern Standard Time (EST) on March 7, 2022, Unit 1 received inadvertent High-Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) initiation signals. Subsequently, at approximately 0148 EST on March 7, 2022, Unit 1 received inadvertent Low-Pressure Coolant Injection (LPCI) and Core Spray initiation signals. In addition, all four Emergency Diesel Generators auto started, Group 10 (Instrument Air) Primary Containment Isolation System actuations occurred, and the Residual Heat Removal (RHR) Service Water Booster pumps tripped resulting in a brief interruption (approximately 9 minutes) to the Shutdown Cooling (SDC) heatsink. Jumpers, installed per planned refueling outage activities, prevented discharge of Emergency Core Cooling Systems into the reactor. HPCI, RCIC, and RHR Loop `A' were removed from service and under clearance. RHR SDC remained operable via RHR Loop `B' and forced circulation was maintained in the reactor. At the time of these events, Unit 1 was shutdown for refueling and the `A' and `C' reactor water level transmitters had been isolated in preparation for planned replacement. Leak-by of the instrument isolation valves occurred on both transmitters. Leak-by on the `C' instrument occurred at a faster rate with the `A' instrument providing the confirmatory signals resulting in Low Level 2 (LL2) and Low Level 3 (LL3) indication at approximately 0040 EST and 0148 EST, respectively. All actuations occurred as designed for LL2 and LL3 signals. During these events, reactor water level remained stable at the Reactor Vessel Head Flange and the `B' and `D' reactor water level transmitters remained off-scale-high, as expected under these conditions. Therefore, the actuations were not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system (i.e., there was no low reactor water level condition). Considering the above, these actuations were invalid. There was no impact on the health and safety of the public or plant personnel.
ENS 5585623 April 2022 06:04:00CatawbaNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: On April 23, 2022, at 0224 (EDT) hours, with Unit 2 in Mode 1 at 100 percent power, two control rods dropped during control rod testing resulting in misalignment, which required a manual reactor trip in accordance with plant procedure. All safety systems functioned as expected. The Auxiliary Feedwater system actuated as designed to provide makeup flow to the steam generators. Operations responded and stabilized the plant. Decay heat is being removed by the steam generator power operated relief valves. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The automatic start of the Auxiliary Feedwater system is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). The cause of the dropped rods is being investigated. Unit 1 is not affected. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified." The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Electrical power is in normal off-site arrangement. All emergency electrical supplies are available.
ENS 5580023 March 2022 16:43:00OconeeNRC Region 2B&W-L-LPThe following information was provided by the licensee via email and phone: At 1625 (EST) on 2/13/2022, with Unit 2 in Mode 3 at 0 percent power and plant heat up to normal operating temperature in progress, an actuation of the Emergency Feedwater System (EFW) occurred. The reason for the EFW auto-start was lowering water level in the 2A and 2B Steam Generators due to failure of the 2A Main Feedwater Pump to respond as required to maintain Steam Generator water level as Steam Generator pressure increased during plant heat up. The 2A and 2B Motor Driven Emergency Feedwater (MDEFW) pumps automatically started as designed when the 'low steam generator level' signal was received for the 2A and 2B Steam Generators. Following further evaluation, it was determined that a valid EFW actuation occurred, therefore this event is being reported as a late 8-hour non-emergency notification of a valid actuation of the EFW system in accordance with 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 557809 March 2022 23:20:00BrunswickNRC Region 2GE-4

The following information was provided by the licensee: At 2013 EST on March 9, 2022, the HPCI System was declared inoperable following evaluation of routine HPCI surveillance testing data indicating that the required response time for reaching rated conditions was not met. Therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The Reactor Core Isolation Cooling (RCIC) System and Automatic Depressurization System (ADS) are operable. There was no impact on the health and safety of the public or plant personnel. Investigation is in-progress to determine the cause. Unit 1 is not affected by this event. Unit 1 is in a refueling outage. The NRC Resident Inspector has been notified.

  • * * RETRACTION ON 05/04/22 AT 1135 EDT FROM CHARLIE BROOKSHIRE TO DAN LIVERMORE * * *

The following information was provided by the licensee via email: At 20:13 EST on March 9, 2022, the HPCI System was declared inoperable following evaluation of routine HPCI surveillance testing data indicating that the required response time for reaching rated flow and pressure was not met. Subsequent to this, it was determined that the required response time was overly conservative for assuring the safety function of the system could be fulfilled. The required response time was revised. The operability determination for this event has been updated indicating that system operability was never lost for this event. There was not a condition that could have prevented the system from fulfilling the safety function. The NRC Resident Inspector has been notified. Notified R2DO (Miller).

ENS 5575825 February 2022 16:10:00McGuireNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee: On 2/25/22, at 1133 EDT, the Technical Support Center (TSC) high temperature alarm annunciated in the Control Room due to an equipment malfunction that resulted in an unplanned loss of the TSC for greater than seventy-five minutes. If an emergency had been declared requiring TSC activation during this period, the TSC would have been staffed and activated using existing emergency planning procedures. If relocation of the TSC had been necessary, the Emergency Coordinator would have relocated the TSC staff to an alternate location in accordance with applicable site procedures. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the equipment malfunction affected the functionality of an emergency response facility. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5575624 February 2022 14:35:00BrunswickNRC Region 2GE-4The following information was provided by the licensee via email: This 60-day optional telephone notification is being made in lieu of an LER (Licensee Event Report) submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 1316 Eastern Standard Time (EST) on January 4, 2022, during performance of isolation logic periodic testing associated with Primary Containment Isolation System Groups 2 and 6, an invalid actuation of Group 6 Primary Containment Isolation Valves (PCIVs) (i.e., Containment Atmospheric Control/Monitoring (CAC/CAM) and Post Accident Sampling (PASS) isolation valves) occurred. This resulted in a Division I CAC isolation signal, a full CAM isolation, and a full PASS isolation. Reactor Building Ventilation isolated and Standby Gas Treatment started per design. No manipulations associated with the isolation or reset logic were ongoing at the time. Troubleshooting determined that the Group 6 isolation signal resulted from a high resistance contact on a relay associated with the main stack radiation high-high isolation logic. This condition interrupted electrical continuity and prevented the Group 6 logic from resetting. Following cleaning of the relay contacts, the isolation logic remained in the reset state. The main stack radiation monitor is a shared component that sends isolation signals to Unit 1 and Unit 2. It was verified that the radiation monitor was not in trip electrically and there were no Unit 2 actuations. Therefore, the actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. As a result, this event has been determined to be an invalid actuation. This event did not result in any adverse impact to the health and safety of the public. The NRC Resident Inspector was notified.
ENS 5575022 February 2022 01:44:00OconeeNRC Region 2B&W-L-LP

The following information was provided by the licensee via fax or email: At 2207 (EST) on 2/21/2022 with Unit 2 in Mode 1 at 68 percent power, the reactor was manually tripped due to lowering water level in the 2A Steam Generator. The trip was not complex with all systems responding normally post-trip. Operators responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Units 1 and 3 were not affected. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non- emergency notification per 10 CFR 50.72(b)(2)(iv)(B). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."

  • * * UPDATE ON 3/23/22 AT 1643 EDT FROM CHRIS MCDUFFIE TO TOM KENDZIA * * *

The following information was provided by the licensee via phone and email: On 2/21/2022, Unit 2 was in Mode 1 increasing reactor power following startup from a forced outage. At 2205 (EST) with Unit 2 at 68 percent power, a feedwater control valve failed to properly control feedwater flow to the 2A Steam Generator and the Integrated Control System initiated an automatic runback. At 2207 (EST), the reactor was manually tripped from 39 percent power due to lowering water level in the 2A Steam Generator. Immediately following the manual reactor trip, an actuation of the Emergency Feedwater System (EFW) occurred. The 2A and 2B Motor Driven Emergency Feedwater (MDEFW) pumps automatically started as designed when the 'low steam generator level' signal was received for the 2A Steam Generator. The trip was not complex with all systems responding normally post-trip. Operators responded and stabilized the plant. Decay heat was removed by discharging steam to the main condenser using the turbine bypass valves. Units 1 and 3 were not affected. Unit 2 was restarted on 2/27/2022 following repairs. Due to the Reactor Protection System actuation while critical, this event was reported on 2/22/2022 as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Following further evaluation, it was determined that a valid EFW actuation occurred, therefore this event is now also being reported as a late 8-hour non-emergency notification of a valid actuation of the EFW system in accordance with 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. Notified the R2DO (Miller).

ENS 5574818 February 2022 08:35:00McGuireNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via telephone and email: On 2/18/2022, McGuire Nuclear Station Unit 2 experienced a turbine runback to 55 percent power. Based on concerns with unit stability, the reactor was manually tripped at 0459 (EST). All Auxiliary Feedwater pumps started on low steam generator level as required. The reactor trip was uncomplicated with all systems responding normally post trip. A feedwater isolation occurred as designed. Unit 1 was not affected. Due to the Reactor Protection System actuation while critical, actuation of the Turbine Driven Auxiliary Feedwater Pump and Motor Driven Auxiliary Feedwater pumps along with the Feedwater Isolation, this event is being reported as a four hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B) and an 8 hour nonemergency notification per 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: All control rods fully inserted. Decay heat is being removed via the condenser and normal feedwater. Unit 2 is in a normal shutdown electrical lineup.
ENS 557335 February 2022 04:32:00OconeeNRC Region 2B&W-L-LP

The following information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: At 0357 EST on 2/5/22, Oconee Unit 2 declared an Unusual Event due to a multiple fire alarms and visual observance of a smoke filled room in the West Penetration Room (EAL HU 4.1). Unit 2 automatically tripped and entered Mode 3. There was an indication that a release to the environment potentially occurred. Units 1 and 3 remained at 100% power. The Licensee notified the NRC Resident Inspector, the State, and local authorities. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), and DHS Nuclear SSA (email).

  • * * UPDATE ON 2/5/22 AT 0748 EST FROM CHUCK CLEMONS TO LLOYD DESOTELL * * *

The following information was provided by the licensee via email: At 0343 EST on February 5th, 2022, with Unit 2 in Mode 1 at 100% power, the reactor automatically tripped due to Reactor Coolant Pump (RCP) Flux/Flow Imbalance caused by the simultaneous trip of all 4 RCPs. The cause of the loss of all RCPs is under investigation. The trip was not complex. There was no inoperable equipment prior to the event that contributed to it. Operations responded and stabilized the plant. Decay heat is being removed by the Reactor Coolant System (RCS) in natural circulation with normal feedwater flow. Due to the Reactor Protection System (RPS) actuation while critical, this event is being reported as a four hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The Licensee notified the State and local authorities. Notified R2DO (Miller)

  • * * UPDATE ON 2/5/22 AT 0815 EST FROM CHUCK CLEMONS TO LLOYD DESOTELL * * *

The following information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: At 0811 EST on 2/5/22, Oconee Unit 2 terminated the notification of unusual event because EAL HU 4.1 criteria were no longer met. Unit 2 remains shutdown in Mode 3. The licensee has notified the State and local authorities and will notify the NRC Resident Inspector. Notified R2DO (Miller), IRD MOC (Gott), NRR EO (Regan), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).

  • * * UPDATE ON 2/7/22 AT 2342 EST FROM PATRICK GADSBY TO OSSY FONT * * *

The following information was provided by the licensee via email: The follow-up investigation determine that the cause of the trip was determined to be a failed fuse in an undervoltage monitoring circuit for the electrical bus powering the reactor coolant pumps. The trip of the reactor coolant pumps resulted in an automatic reactor trip as designed. The plant responded as expected. There was no fire. The response of the main feedwater system caused an expected increase in temperature in a standby portion of the system which caused the breakdown of the pipe coating producing smoke. There was no release to the environment. The reading of a single instrument was determined to be invalid and other indications supported the conclusion that no release occurred. The following information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The Licensee notified the NRC Resident Inspector, State and local authorities. A media release was issued on 2/5/22. Notified R2DO (Miller), IRD MOC (Gott), NRR EO (Regan).

ENS 5571326 January 2022 18:49:00OconeeNRC Region 2B&W-L-LP

Licensee provided the following information via email: At 1050 EST on January 26, 2022, it was discovered that the required offsite and the overhead and underground paths of onsite emergency AC power were simultaneously inoperable; therefore this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(A). The overhead path and both required offsite paths were inoperable due to a lockout of the Unit 3 Startup Transformer CT-3. The underground path was made momentarily inoperable as part of aligning an additional offsite power source to Unit 3 to provide defense in depth to a loss of power. The safety function was restored at 1051 EST when the underground path was declared OPERABLE. The offsite power source was restored at 1651 EST. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

  • * * UPDATE ON 1/26/22 AT 2237 EST FROM GABE SLAUGHTER TO KAREN COTTON * * *

The Licensee updated the 3rd paragraph above as follows via email: The safety function was restored at 1051 EST when the underground path was declared OPERABLE. An offsite power source was restored through Transformer CT-5 within 15 minutes. Startup transformer CT-3 was restored and all offsite and the onsite overhead power source were returned to service by 1651 EST. Investigation of the cause of the CT-3 lockout is in progress. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified of this update.

ENS 5567427 December 2021 16:49:00HarrisNRC Region 2Westinghouse PWR 3-Loop

The following information was provided by the licensee via email: On December 27, 2021, at 1014 EST, a system error in the site's Alert and Notification Siren System was identified, indicating a loss of the siren system affecting a greater than 25% of the emergency planning zone population. Review of the system's data logger indicates the system error has been present within the system since December 22, 2021, at 1245 EST. The fleet's telecommunications department has been contacted and is aware of the issue. In the event that a radiological emergency should occur at the Shearon Harris Nuclear Power Plant, Primary Route Alerting procedures will be put in use by the local jurisdictions. This condition is reportable as a Loss of Emergency Preparedness Capabilities per 10 CFR 50.72(b)(3)(xiii). The NRC Resident, state and local agencies have been notified.

  • * * RETRACTION ON 12/29/21 AT 1630 EST FROM SARAH MCDANIEL TO KAREN COTTON * * *

The following information was provided by the Licensee via email: Further troubleshooting efforts identified that the Chatham County EOC Siren Activation Point remained capable of sending an alert signal to the sirens for the duration of the event described above. This ensures siren activation would be performed in a timely manner in the event of a radiological emergency. This Event Notification is therefore retracted, as no loss of emergency preparedness capabilities has occurred. The NRC Resident and local agencies have been notified. Notified R2DO (Miller)

ENS 5564915 December 2021 16:45:00HarrisNRC Region 2Westinghouse PWR 3-Loop
  • The following information was provided by the licensee via email:

At 0927 EST on December 15, 2021, it was determined that a non-licensed employee supervisor failed a test specified by the fitness for duty (FFD) testing program. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified.

ENS 5563810 December 2021 03:54:00OconeeNRC Region 2B&W-L-LPAt 0049 EST, on December 10, 2021, with Unit 2 in Mode 1 at 73 percent power, the reactor automatically tripped due to an unknown condition. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being maintained by discharge steam to the main condenser using the turbine bypass valves. Units 1 and 3 are not affected. The cause of the trip is under investigation. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)iv)(B). There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. All rods inserted into the core during the trip. The plant is in its normal shutdown electrical lineup maintaining normal operating pressure and temperature.
ENS 556276 December 2021 18:14:00BrunswickNRC Region 2GE-4

On December 6, 2021, at 1125 hours Eastern Standard Time (EST), during planned maintenance activities, electrical power was lost to the 4160V emergency bus E-3. The power loss to emergency bus E-3 affected both Unit 1 and 2. Emergency Diesel Generator #3 received an automatic start signal but was under clearance for planned maintenance. Emergency bus E-3 was re-energized at 1315 EST hours via offsite power. The loss of power to E3 resulted in Unit 2 Primary Containment Isolation System (PCIS) Group 2 (i.e., Drywell Equipment and Floor Drain, Residual Heat Removal (RHR) Discharge to Radwaste, and RHR Process Sample), Group 3 (i.e., Reactor Water Cleanup), Group 6 (i.e., Containment Atmosphere Control/Dilution, Containment Atmosphere Monitoring, and Post Accident Sampling Systems), and Group 10 (i.e., air isolation to the drywell) isolations. The actuations of PCIVs were completed and the affected equipment responded as designed. Per design, no Unit 1 safety system group isolations or actuations occurred. Other Unit 2 actuations included the Reactor Building Ventilation System isolation (i.e., Secondary Containment isolation), and the automatic start signal to the Standby Gas Treatment (SGT) System trains A and B and the Control Room Emergency Ventilation System (CREV). Systems functioned as designed. Safety systems functioned as designed following the de-energization of bus E-3. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of PCIS on Unit 2 and an automatic start signal to Emergency Diesel Generator #3. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. Except for the Emergency Diesel Generator, which is out of service for planned maintenance, all equipment has been returned to its normal alignment.

  • * * UPDATE FROM JJ STRNAD TO THOMAS KENDZIA AT 2028 EST ON DECEMBER 6, 2021 * * *

The loss of power to E3 resulted in Unit 1 Primary Containment Isolation System (PCIS) Group 6 (i.e., Containment Atmosphere Control/Dilution, Containment Atmosphere Monitoring, and Post Accident Sampling Systems). Other Unit 1 actuations included the Reactor Building Ventilation System isolation (i.e., Secondary Containment isolation), and the automatic start signal to the Standby Gas Treatment (SGT) System trains A and B and the Control Room Emergency Ventilation System (CREV). Systems functioned as designed. Safety systems functioned as designed following the de-energization of bus E-3. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of PCIS on Unit 1. All Unit 1 equipment was returned to its normal alignment. The NRC Resident will be notified. Notified R2DO (Miller).

ENS 5561227 November 2021 13:16:00OconeeNRC Region 2B&W-L-LPAt 0519 EST on November 27, 2021, with Unit 2 in Mode 5 at zero percent power, an actuation of the Emergency AC Electrical Power System occurred. The reason for the Emergency AC Electrical Power System auto-start was a lockout of the CT-2 transformer; causing a temporary loss of AC power to the main feeder bus. The Keowee Hydroelectric Units 1 and 2 automatically started as designed when a main feeder bus undervoltage signal was received. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the Emergency AC Electrical Power System. Additionally, the temporary loss of AC power resulted in a loss of Decay Heat Removal (DHR) that was restored upon power restoration to the main feeder bus. Therefore, this condition is also being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v) for an event or condition that could have prevented fulfillment of a safety function. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The loss of the CT-2 transformer is under investigation. Main feeder bus power was restored within a minute so no plant heat up occurred as a result of the loss of the decay heat removal system.
ENS 5554927 October 2021 20:39:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 1429 EDT on October 27, 2021 with Unit 1 in Mode 6 at 0 percent power, the 1B Emergency Diesel Generator (EDG) Load Sequencer was actuated by a valid undervoltage condition on the 1B 4160V Essential Bus that occurred during 1B Sequencer calibration activities. Valid signals were sent to both the 1B EDG and Unit 1 Auxiliary Feedwater (CA) systems. Neither system automatically started as they were both removed from service for maintenance activities at the time. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the 1B EDG and Unit 1 CA systems. There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5552315 October 2021 08:52:00OconeeNRC Region 2B&W-L-LPAt 1727 (EDT) on October 14, 2021, it was determined that a licensed operator failed a test specified by the Fitness-For-Duty (FFD) testing program. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified.
ENS 5545813 September 2021 05:53:00McGuireNRC Region 2Westinghouse PWR 4-LoopAt 0011 EDT, with Unit 2 in Mode 5 (Cold Shutdown), actuations of the 2B Diesel Generator (DG) and the 2B Motor Driven Auxiliary Feedwater (AFW) Pump occurred during Engineered Safety Features Actuation Periodic Testing while resetting the 2B DG Load Sequencer. The 2B DG was running unloaded following test actuation, and during realignment from the test, a blackout condition was experienced when the breaker opened supplying the 4160 Volt Essential Power System 2ETB from the Standby Auxiliary Power Transformer SATB. Sequencer actuation closed the emergency breaker to 2ETB and loaded the 2B Motor Driven AFW Pump onto the bus. Steam supply valves to the Turbine Driven AFW Pump were open from the previous test configuration. This event is being reported in accordance with 10CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the 2B DG and the 2B Motor Driven AFW Pump. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 553394 July 2021 15:59:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 0911 EDT on July 4, 2021, a failure occurred on 2 out of 3 of the required seismic monitoring instruments that feed the Operational Basis Earthquake (OBE) annunciator. The failure would prevent an OBE EXCEEDED alarm on the Seismic Monitoring Panel in the Control Room. This results in a major loss of emergency assessment capability. Corrective actions are being pursued to restore the seismic monitoring instruments. Compensatory measures are in place to assure adequate monitoring capability. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the unplanned failure of the required seismic instruments affects the ability to assess a seismic event greater than the OBE. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5527525 May 2021 21:38:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 1751 EDT on May 25, 2021, it was determined the local leak rate test (LLRT) for the 2EMF-IN containment penetration did not meet 10 CFR 50 Appendix J requirements for both the inboard and outboard containment isolation valves (2MISV5230 and 2MISV5231). The LLRT was performed during the previous refueling outage at which time primary containment was not required to be operable. The leakage assigned to the penetration also resulted in total leakage exceeding the allowed overall leakage. The valves were repaired and retested satisfactory prior to entering the mode of applicability, This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A), There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 552291 May 2021 15:39:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 0755 EDT, on May 1, 2021, with Unit 2 in Mode 3 at 0 percent (not critical) power, the reactor trip breakers opened during heat-up activities. The trip was not complex, with all systems responding normally post-trip. At 1013 EDT, on May 1, 2021, with Unit 2 in Mode 3 at 0 percent power, an actuation of the Auxiliary Feedwater (AFW) System occurred. The loss of both main feedwater pump turbines caused an AFW auto-start. The 2A and 2B motor driven auxiliary feedwater (MDAFW) pumps automatically started as designed when the loss of both main feedwater pumps signal was received. The cause of the actuation is still being evaluated. Operations responded and stabilized the plant. Decay heat is being removed by the steam generators and discharging steam to the condenser. Unit 1 is not affected. Due to the Reactor Protection System (RPS) actuation while not critical and the actuation of the AFW system, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5521325 April 2021 11:50:00HarrisNRC Region 2Westinghouse PWR 3-LoopAt 1200 EDT on April 25, 2021, planned maintenance activities on the Harris Nuclear Plant Seismic Monitoring System will be performed. The work includes performance of preventive maintenance and system upgrades. The work duration is approximately 10 days and compensatory measures will be in place for seismic monitoring. This is an eight-hour, non-emergency notification for a planned loss of emergency assessment capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii). There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5520121 April 2021 02:37:00CatawbaNRC Region 2Westinghouse PWR 4-LoopDuring the performance of reactor vessel closure head (RVCH) examinations, at 2230 EDT on April 20, 2021, it was determined that the Unit 2 RVCH penetration nozzle number 74 did not meet the requirements of 10CFR50.55a(g)(6)(ii)(D) and ASME code case N-729-6 . All other RVCH penetration examinations have been completed per 10CFR50.55a(g)(6)(ii)(D) and ASME code case N-729-6 with no other relevant indications identified. The condition of the Unit 2 reactor vessel head penetration nozzle number 74 will be resolved prior to re-installation of the Unit 2 RVCH. This event is being reported as an eight-hour, non-emergency notification per 10CFR50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5519114 April 2021 13:00:00BrunswickNRC Region 2GE-4This 60-day optional telephone notification is being made in lieu of an LER submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 1507 EDT on February 17, 2021, during performance of isolation logic periodic testing associated with Primary Containment Isolation System Groups 2 and 6, an invalid actuation of Group 6 Primary Containment Isolation Valves (PCIVs) (i.e., Containment Atmospheric Control/Monitoring and Post Accident Sampling isolation valves) occurred. The Group 6 isolation signal resulted from the reactor building ventilation radiation monitor `B' Channel exceeding the setpoint value. This condition likely resulted from the radiation monitor electronics being impacted by humidity levels, which exceeded the instrument design requirements that developed in the area over time as a result of the Unit 2 reactor building ventilation being secured per the test procedure. The `A' Channel, located in the same plenum, remained steady and below the setpoint value through the entire event. This, along with readings made by a Radiation Protection Technician, confirmed that there was no actual high radiation condition in the reactor building exhaust. Upon returning Unit 2 reactor building ventilation to service, the `B' Channel readings returned to be consistent with the `A' Channel. The PCIVs functioned successfully and the actuation was complete. The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation. This event did not result in any adverse impact to the health and safety of the public. The NRC Resident Inspector was notified.
ENS 550999 February 2021 11:00:00RobinsonNRC Region 2Westinghouse PWR 3-LoopAt approximately 0800 on February 9, 2021, thirty-one (31) H.B. Robinson Nuclear Plant Offsite Emergency Notification sirens in Darlington County, SC were inadvertently actuated. The Darlington County Emergency Services and South Carolina Emergency Management Division were promptly notified. The actuation lasted for three (3) minutes at full volume. The cause of the actuation is under investigation at this time. Capability to notify the public was never degraded during the inadvertent actuation. All Emergency Notification sirens remain in service. This notification is being made in accordance with 10 CFR 50.72(b)(2)(xi), Offsite Notification, as a four (4) hour report. The NRC Resident Inspector has been notified. A local news agency did report about the alarms sounding and reported that there was no concern at the site.
ENS 5507921 January 2021 17:10:00RobinsonNRC Region 2Westinghouse PWR 3-LoopThis 60-day optional telephone notification is being made in lieu of an LER submittal, as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At 0946 hrs on December 1, 2020, with unit 2 in Mode 5 at 0% power, an invalid actuation of the Emergency Diesel Generators (EDG) 'A' and 'B', 'A' Residual Heat Removal (RHR) Pump, 'A' Service Water Booster Pump (SWBP), and Auxiliary Feed Water (AFW) Pumps 'A' and 'B' occurred. The actuation was caused by a Safety Injection (SI) signal while installing simulations to support Reactor Safeguards testing. The SI signal occurred when two out of three logic was met for Low Pressurizer Pressure, which was caused by a high resistance connection to a test point from a loose test lead. All aligned equipment, 'A' and 'B' EDGs, 'A' RHR Pump, 'A' SWBP and 'A' and 'B' AFW Pumps, responded properly to the auto-start signal and the actuation was complete. The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector was notified.
ENS 5504017 December 2020 22:03:00HarrisNRC Region 2Westinghouse PWR 3-LoopOn December 17, 2020 at 1539 EST, with Harris Nuclear Plant Unit 1 preparing for entry into Mode 4, the Reactor Coolant System was pressurized greater than 1000 psig for approximately 15 minutes with all three Cold Leg Injection Accumulator Discharge Valves closed. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). Both Low Head and High Head Safety Injection Systems were operable at this time. This condition does not affect the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5503816 December 2020 12:19:00HarrisNRC Region 2Westinghouse PWR 3-LoopOn December 16, 2020 at 0851 EST, with Harris Nuclear Plant Unit 1 in Mode 1 at 80 percent power, an automatic reactor trip occurred due to lockout of the main generator. The trip was not complex, with all systems responding normally post-trip. The initial assessment of this event indicates that there was a ground fault on the 'B' train of the non-safety electrical distribution system that caused the main generator lockout. Steam generator levels are being maintained by normal feedwater through the feedwater regulator bypass valves. Decay heat is being removed by using the condenser steam dump flow path. Due to the unplanned Reactor Protection System actuation while critical, this event is being reported as a four hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This condition does not affect the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. All rods inserted into the core during the trip. The electrical grid is stable and all safe shutdown equipment is available for service. No reliefs lifted during the transient.
ENS 550171 December 2020 17:00:00HarrisNRC Region 2Westinghouse PWR 3-LoopOn December 1, 2020 at 1116 EST, a condition impacting functionality of the Technical Support Center (TSC) Ventilation System was discovered during surveillance testing. The issue resulted in a loss of TSC functionality due to a high flow rate measured on outside air intake fans. The cause of the high flow rate is under investigation. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the condition affects the functionality of an emergency response facility. If an emergency is declared requiring TSC activation during the non-functional period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Coordinator will relocate the TSC staff to an alternate location in accordance with site procedures. This condition does not affect the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5494311 October 2020 10:25:00CatawbaNRC Region 2At 0315 (EDT) on October 11, 2020, Unit 2 ECCS (Emergency Core Cooling System) leakage outside containment was determined to exceed the long term habitability dose analysis for the Catawba Nuclear Station Technical Support Center (TSC) under bounding conditions. At the current leakage (approximately 3.2 gpm), the dose analysis indicates dose to TSC inhabitants would exceed the 30 days REM TEDE (Total Effective Dose Equivalent) limit should leakage continue for the entire duration. Repairs are currently in-progress to arrest the leakage and restore functionality of the TSC. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to the alternate facility. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the discovered condition of the TSC affects the functionality of an emergency response facility, There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 549346 October 2020 20:16:00HarrisNRC Region 2A non-licensed employee supervisor had a confirmed positive during a random fitness-for-duty test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified.
ENS 5489812 September 2020 21:12:00CatawbaNRC Region 2At 1748 EDT on September 12, 2020, Unit 2 emergency core cooling system (ECCS) leakage outside containment was determined to exceed the long-term habitability dose analysis for the Catawba Nuclear Station Technical Support Center (TSC) under bounding conditions. Repair options to arrest the leakage and restore functionality of the TSC are currently being evaluated. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to the alternate facility. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable In accordance with 10 CFR 50.72(b)(3)(xiii) because the discovered condition of the TSC affects the functionality of an emergency response facility. There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. This same condition was reported under EN #54887.
ENS 548888 September 2020 13:13:00CatawbaNRC Region 2At 0925 EDT, on September 8, 2020, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped on Overpower Delta Temperature. Unit 1 Channel 1 Overpower Delta Temperature was tripped as a planned evolution when an inadvertent Unit 1 Channel 2 Overpower Delta Temperature signal was received. This resulted in an automatic reactor trip. The trip was not complex, with all systems responding normally. Because of the reactor trip, the Auxiliary Feedwater (AFW) System actuated as expected due to on ATWS Mitigation System Actuation Circuitry (AMSAC) signal. Unit 2 is not affected. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the condenser steam dump valves. Due to the Reactor Protection System (RPS) actuation while critical, this event is being reported as a 4-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an 8-hour non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the AFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 548876 September 2020 11:39:00CatawbaNRC Region 2At 034S (EDT) on September 6, 2020, Unit 2 ECCS leakage outside containment was determined to exceed the long term habitability dose analysis for the Catawba Nuclear Station Technical Support Center (TSC) under bounding conditions. Repairs are currently in-progress to arrest the leakage and restore functionality of the TSC. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC: becomes uninhabitable. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to the alternate facility. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the discovered condition of the TSC affects the functionality of an emergency response facility. There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5483413 August 2020 13:24:00HarrisNRC Region 2On August 13, 2020, at 0938 EDT, with Harris Nuclear Plant Unit 1 in Mode 1 at 100 percent power, a control rod dropped during control rod testing. This is considered to be an unanalyzed condition and requires a manual reactor trip in accordance with plant procedure. All safety systems functioned as expected. Auxiliary Feedwater started as designed and was secured. Steam generator levels are being maintained by Main Feedwater through the feedwater regulator bypass valves. Decay heat is being removed by using the condenser steam dump flow path. Due to the RPS actuation, this event is being reported as a four hour non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Due to the unanalyzed condition and unplanned Auxiliary Feedwater actuation, this event is also being reported as an eight hour non-emergency notification per 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.