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| Entered date | Site | Region | Reactor type | Event description | |
|---|---|---|---|---|---|
| ENS 57021 | 11 March 2024 15:46:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee via phone and email: On March 11, 2024, at 1337 EDT, with Unit 1 in Mode 1 at 35 percent power performing power ascension activities, the reactor was manually tripped due to the 'A' reactor feed pump (RFP) tripping on low suction pressure. Due to the power level at the time, the 'B' RFP had not been placed in service. Closure of containment isolation valves (CIVs) in multiple systems and actuation of high-pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) occurred as a result of reaching the actuation setpoint on reactor water level as designed. The trip was not complex, with all safety systems responding normally post-trip. Operations responded and stabilized the plant. The 'B' RFP was placed in service and is controlling reactor water level. Decay heat is being removed by discharging steam to the main condenser using turbine bypass valves. Unit 2 is not affected. Due to the emergency core cooling system (ECCS) discharging into the reactor, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(A). Also, the Reactor Protection System actuation while critical is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Additionally, it is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of CIVs, RCIC and HPCI. 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 'A' RFP is under investigation. The reactor electric plant remains in a normal lineup with both emergency diesel generators available. There were no temperature or pressure technical specification limits approached. |
| ENS 56975 | 18 February 2024 16:02:00 | Hatch | NRC Region 2 | GE-4 | The following is a synopsis of information was provided by the licensee via email and phone call: A non-licensed supervisor had a confirmed positive during a random fitness for duty test. The supervisor's access to the plant has been terminated. |
| ENS 56971 | 16 February 2024 05:34:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: At 0048 CST on February 16, 2024, with Unit 2 in mode 1 at 100 percent power, the reactor was manually tripped due to a loss of 2A 125V DC distribution panel. The trip was complex due to the loss of components associated with A-train DC power. Operations responded and stabilized the plant. Decay heat is being removed by the atmospheric relief valves. Unit 1 is not affected. An automatic actuation of the auxiliary feedwater system (AFW) occurred due to low-low steam generator levels. The AFW auto-start is an expected response with low-low steam generator levels from the reactor trip. AFW is still currently controlling steam generator levels. 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 as an eight-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 56959 | 11 February 2024 11:38:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee via email: At 1011 EST on 02/11/2024, during a refueling outage at 0 percent power, while performing local leakage rate testing (LLRT) of the feedwater check valves (part of the containment boundary), it was determined that the Unit 1 primary containment leakage rate did not meet 10 CFR 50 Appendix J requirements specified in Technical Specification 5.5.12. 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 56897 | 18 December 2023 13:34:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee via email and phone: At 2011 EDT on 11/01/23, with Unit 2 in Mode 3 at 0 percent power, Unit 2 received multiple spurious actuations. These actuations consisted of a partial group 1 and a partial group 5 primary containment isolation and a partial secondary containment isolation. The partial Group 1 isolation resulted in the closure of two main steam isolation valves (MSIVs); all other MSIVs were already closed. The partial group 5 isolation auto closed one of the reactor water cleanup (RWCU) isolation valves. The partial secondary containment isolation resulted in the closure of the inboard refueling floor and reactor building secondary containment isolation valves (SCIVs). Additionally, at 2238 EDT, Unit 2 again received multiple spurious actuations. These actuations consisted of a partial group 5 primary containment isolation and a partial secondary containment isolation. The partial group 5 isolation auto closed one of the RWCU isolation valves The partial secondary containment isolation resulted in the closure of the inboard refueling floor and reactor building SCIVs. And again, at 2354 EDT, Unit 2 received spurious actuations which consisted of a partial secondary containment isolation which resulted in the closure of the inboard refueling floor and reactor building SCIVs. The spurious actuations seen on 11/1/23 are triggered at -35 inches reactor water level (RWL) for group 5 and secondary containment isolations and at -101 inches RWL for group 1 isolations. It was determined that a combination of the RWL fluctuating above and below the wide range instrument reference leg tap, the reactor vessel pressure being lowered, and reactor core isolation cooling introducing colder water conditions near the reference leg tap of the wide range instrument caused the spurious actuations. Using multiple RWL indications for each of the instances mentioned above, the actuations were confirmed to be spurious as RWL was being controlled in a band of +55 inches to +85 inches at the time of the actuations. This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that resulted in an invalid actuation of a partial group 1, a partial group 5, and partial secondary containment logic. The NRC Resident has been notified. |
| ENS 56896 | 18 December 2023 07:40:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee email: At 0223 EST, on 12/18/2023, while Unit 2 was at 100 percent power in mode 1, the high pressure coolant injection (HPCI) outboard steam isolation valve closed resulting in the HPCI system being declared inoperable. The cause of the outboard steam isolation valve closing is under investigation. HPCI does not have a redundant system, therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The safety function was restored at 0512, on 12/18/23, and HPCI has been declared operable. Reactor core isolation cooling (RCIC) and low pressure emergency core cooling systems (ECCS) were operable during this time. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 56852 | 14 November 2023 14:36:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 1041 CST on 11/14/23 with Farley Unit 2 in Mode 1 at 10 percent power, the reactor was manually tripped due to rising steam generator levels. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Auxiliary feedwater (AFW) was manually initiated in accordance with plant procedures and is feeding the steam generators. Heat removal is being provided via the atmospheric relief valves. 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). This event is also being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results 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: All rods fully inserted. The licensee attempted to take manual control of the feedwater control valves to lower steam generator level but, due to reaching a steam generator level that requires a manual trip, the licensee manually tripped the reactor. |
| ENS 56826 | 1 November 2023 09:38:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee via email: At 0648 EDT on 11/1/23, with Unit 2 in MODE 1 at 56 percent power, the reactor was manually tripped due to a trip of the 'B' reactor feed pump (RFP). The 'A' RFP had been previously isolated due to a leak. Closure of containment isolation valves (CIVs) in multiple systems and the actuation of high pressure coolant injection (HPCI) and reactor core isolation cooling (RCIC) occurred as a result of reaching the actuation setpoint on reactor water level as designed. The trip was not complex, with all safety systems responding normally post-trip. Operations responded and stabilized the plant. Reactor water level is being maintained with RCIC. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 1 was not affected. Due to the emergency core cooling system (ECCS) discharging into the reactor this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(A). Also, the reactor protection system actuation while critical is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). Additionally, it is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of CIVs, RCIC and HPCI. There was no impact on the health and safety of the public or plant personnel. The Resident Inspector was notified. |
| ENS 56784 | 9 October 2023 21:52:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: A non-licensed employee supervisor failed a test specified by the fitness for duty testing program. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified. |
| ENS 56779 | 5 October 2023 12:29:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via phone and email: At 1439 EDT on August 7, 2023, a spurious level spike on the unit 4 reactor coolant system (RCS) level instrument (4-RCS-LT160A, 'Hot Leg 1 Level') caused actuation of containment isolation, reactor trip, automatic depressurization system (ADS) stage 4, and in containment refueling water storage tank (IRWST) isolation signals. The spurious level changes caused an invalid signal based on the incidental response of the 4-RCS-LT160A instrumentation due to water spray that was being used for reactor vessel cleaning (being performed prior to initial fuel loading). The level fluctuations resulted in engineered safety features actuation signals (containment isolation, ADS stage 4, and IRWST isolation signals) and a reactor trip signal, with the reactor trip signal already present. Three containment isolation valves closed due to the containment isolation signal that was generated. These valves were: 4-CAS-V014, 'instrument air supply containment isolation, air-operated valve,' 4-SFS-V034, 'spent fuel pool cooling system suction header containment isolation, motor-operated valve,' and 4-SFS-V035, 'spent fuel pool cooling system suction header containment isolation, motor-operated valve.' The other automatic containment isolation valves were either already closed at the time of the event or properly removed from service. All affected equipment functioned properly. The other actuation signals that were observed during this event (ADS stage 4, IRWST isolation, and reactor trip) did not result in any equipment changing position or automatically operating (i.e., the actuation signals occurred while the systems were properly removed from service). Units 1, 2, and 3 were not affected. This event did not result in any adverse impact to the health and safety of the public. The NRC Resident Inspector was notified. |
| ENS 56648 | 1 August 2023 11:48:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 1506 EDT on July 31, 2023, it was determined that a contractor supervisor failed a test specified by the fitness for duty testing program. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified. |
| ENS 56632 | 21 July 2023 15:06:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 1148 EDT on 07/21/2023, with Unit 3 in Mode 1 at 32 percent power, the reactor automatically tripped on low reactor coolant pump (RCP) speed due to decaying RCP motor voltage during power ascension testing. The trip was not complex, with all safety-related systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam via steam generator power operated relief valves to the atmosphere, and startup feedwater is supplying the steam generators. Units 1, 2, and 4 are 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. |
| ENS 56614 | 9 July 2023 16:57:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 1328 EDT on 07/09/2023, with Unit 3 in Mode 1 at 45 percent power, the reactor automatically tripped during power ascension testing due to low reactor coolant flow from decaying voltage to the reactor coolant pumps. The trip was not complex, with all safety-related systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam via steam generator power operated relief valves to the atmosphere, and startup feedwater is supplying the steam generators. Units 1, 2, and 4 are 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. |
| ENS 56497 | 2 May 2023 07:57:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0423 EDT on 05/02/2023, with Unit 3 in Mode 1 at 14 percent power, the reactor was manually tripped due to securing all main feed pumps, due to sudden high differential pressure on their suction strainers. The trip was not complex, with all safety-related systems responding normally post-trip. No equipment was inoperable prior to the event that contributed to the event or adversely impacted plant response to the reactor trip. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the steam dumps, and startup feedwater is supplying the steam generators. Units 1, 2, and 4 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. |
| ENS 56460 | 10 April 2023 04:34:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0048 EDT on 4/10/2023, with Unit 3 in Mode 1 at 18 percent power, the reactor automatically tripped due to low reactor coolant flow due to voltage decaying to the reactor coolant pumps during main generator testing activities. The trip was not complex, with all safety-related systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam via steam generator power operated relief valves to atmosphere. Units 1, 2, and 4 are 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. |
| ENS 56446 | 31 March 2023 15:54:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee via email: At 1432 EDT on 03/31/23, with Unit 2 in mode 1 at 97 percent power, the reactor was manually tripped due to a loss of both recirculation pumps. The cause of the recirculation pump trips is under investigation. Additionally, closure of CIVs in multiple systems occurred during the trip as a result of reaching the actuation setpoint on reactor water level as designed. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Reactor water level is being maintained via condensate / feedwater. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. 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). It is also reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of CIVs. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 56415 | 16 March 2023 13:23:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0845 EDT on March 16, 2023, it was determined that a contract employee supervisor failed a for-cause FFD test. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified. |
| ENS 56414 | 16 March 2023 01:26:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 2157 EDT on 03/15/2023, with Unit 3 in Mode 1 at 18 percent power, the reactor automatically tripped due to the loss of two reactor coolant pumps when their electrical buses failed to transfer after a main generator excitation protective relay tripped. Operations responded and stabilized the plant. Decay heat is being removed by steam generator power operated relief valves. Units 1, 2, and 4 are not affected. Due to the Reactor Protection System 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. |
| ENS 56367 | 16 February 2023 15:52:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0743 EST on February 16, 2023, it was determined that a contract supervisor failed a random fitness-for-duty (FFD) test. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified. |
| ENS 56342 | 7 February 2023 21:10:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the licensee via email: At 1738 EST on 02/07/2023, while in mode 5 at 0 percent power, it was determined during local leak rate testing (LLRT) that the primary containment leakage rate exceeded the allowable limit defined in 10 CFR 50, Appendix J, 'Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors.' Both primary containment isolation valves in a penetration failed LLRT requirements which represents a failure to maintain primary containment integrity. 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 56329 | 1 February 2023 13:40:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: At 0956 CST with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped due to a turbine trip. The trip was not complex with all safety related systems responding normally post-trip. During the trip, the non safety related '1A' 4160V bus lost power resulting in the loss of one Reactor Coolant Pump (RCP-1A). Operations responded and stabilized the plant. The '1A' 4160V bus was re-energized at 1031 CST. Decay heat is being removed by steam dumps to the main condenser. Farley Unit 2 is not affected. An automatic actuation of (Auxiliary Feedwater) AFW also occurred, which is an expected response from the reactor trip. 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) and an eight-hour report per 10 CFR 50.72(b)(3)(iv)(A) as an event that results 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 56311 | 14 January 2023 14:05:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0721 EST on 01/14/2023, with Unit 3 in Mode 3 at 0 percent power and reactor trip breakers open, a manual actuation of the RPS occurred while conducting pre-criticality testing. The RPS manual actuation was procedurally driven in response to low gland steam pressure, resulting in the necessity to break condenser vacuum following a trip of the auxiliary boiler. The reactor trip breakers were in an open state at the time of the event. 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 RPS. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 56294 | 4 January 2023 06:08:00 | Vogtle | NRC Region 2 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via email: At 2259 EST on 1/3/2023, with Unit 1 and Unit 2 in Mode 1 at 100 percent power, an actuation of the Unit 1 B and Unit 2 A emergency diesel generator (EDG) systems, as well as an actuation of the associated auxiliary feedwater (AFW) systems on each unit occurred. The reason for the EDG auto-starts was due to a loss of an offsite power source (loss of one of the two reserve auxiliary transformers (RAT) on each unit) to the Unit 1 B and Unit 2 A safety related buses. The EDG and AFW systems automatically started as designed when the valid undervoltage signal on the affected safety related bus was received. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the Emergency Diesel Generator and the Auxiliary Feedwater Systems for both Unit 1 and Unit 2. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 56231 | 17 November 2022 20:23:00 | Vogtle | NRC Region 2 | W-AP1000 | A contract supervisor had a confirmed positive for alcohol 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 56175 | 23 October 2022 11:14:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0405 EDT on 10/23/2022, with (Vogtle) Unit 3 in Mode 6 and the reactor subcritical for greater than 28 hours, it was discovered that all three required flow paths for the stage four ADS were simultaneously inoperable; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). The diverse actuation system was operable for manual stage four ADS during this time period. At 0432 EDT on 10/23/2022, two of the three required flow paths were restored to operable status, which exited the reportable condition. All required flow paths were operable at 0447 EDT. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 56147 | 6 October 2022 10:06:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via email: At 0244 EDT on 10/06/2022, with Unit 3 Defueled at 0 percent power, an actuation of the RPS occurred during restoration of Division B Class 1E DC and uninterruptible power supply system. The reason for the RPS actuation was due to the opening of the Division B passive residual heat removal (PRHR) heat exchanger outlet flow control valve. The reactor trip breakers were in an open state at the time of the event when the RPS 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 RPS. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 56112 | 17 September 2022 13:06:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the Southern Nuclear Company via email: At 2257 EDT on 09/16/2022, it was determined that there was a programmatic vulnerability of the Fleet FFD program. Specifically, it was determined that some individuals were not placed into the follow-up pool for additional screening when required by the program. All identified personnel were in the random FFD pool, and were subject to the behavioral observation program. This is reportable in accordance with 10CFR26.719(b)(4) for all Units and 10CFR26.417(b)(1) for Vogtle Units 3&4. The NRC Resident Inspectors have been notified. See EN#s 56113, 56114, and 56115. |
| ENS 56113 | 17 September 2022 13:06:00 | Hatch | NRC Region 2 | GE-4 | The following information was provided by the Southern Nuclear Company via email: At 2257 EDT on 09/16/2022, it was determined that there was a programmatic vulnerability of the Fleet FFD program. Specifically, it was determined that some individuals were not placed into the follow-up pool for additional screening when required by the program. All identified personnel were in the random FFD pool, and were subject to the behavioral observation program. This is reportable in accordance with 10CFR26.719(b)(4) for all Units and 10CFR26.417(b)(1) for Vogtle Units 3 and 4. The NRC Resident Inspectors have been notified. See EN#s 56112, 56114, and 56115. |
| ENS 56114 | 17 September 2022 13:06:00 | Vogtle | NRC Region 2 | Westinghouse PWR 4-Loop | The following information was provided by Southern Nuclear Company via email: At 2257 EDT on 09/16/2022, it was determined that there was a programmatic vulnerability of the Fleet FFD program. Specifically, it was determined that some individuals were not placed into the follow-up pool for additional screening when required by the program. All identified personnel were in the random FFD pool, and were subject to the behavioral observation program. This is reportable in accordance with 10CFR26.719(b)(4) for all Units and 10CFR26.417(b)(1) for Vogtle Units 3 and 4. The NRC Resident Inspectors have been notified. See EN#s 56112, 56113, and 56115. |
| ENS 56115 | 17 September 2022 13:06:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the Southern Nuclear Company via email: At 2257 EDT on 09/16/2022, it was determined that there was a programmatic vulnerability of the Fleet FFD program. Specifically, it was determined that some individuals were not placed into the follow-up pool for additional screening when required by the program. All identified personnel were in the random FFD pool, and were subject to the behavioral observation program. This is reportable in accordance with 10CFR26.719(b)(4) for all Units and 10CFR26.417(b)(1) for Vogtle Units 3 and 4. The NRC Resident Inspectors have been notified. See EN#s 56112, 56113, and 56114. |
| ENS 56028 | 3 August 2022 16:25:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: At 1258 CDT on August 3, 2022, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped due to the supply breakers of the 1B startup transformer opening. The fast dead bus transfer for the reactor coolant pumps did not occur during the event. Currently the plant is in Mode 3 on natural circulation. Operations responded and stabilized the plant. Decay heat is being removed by steaming with atmospheric relief valves. Unit 2 is not affected. An automatic actuation of the 1B diesel occurred because of the power loss to the 1G 4160V bus. Additionally, the actuation of motor driven and turbine driven auxiliary feedwater pumps (AFW) also occurred. AFW auto-start is an expected response from this reactor trip. 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 as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the 1B diesel and 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 55875 | 3 May 2022 18:44:00 | Vogtle | NRC Region 2 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via email: At 1541 EDT on May 3, 2022, with Unit 1 in Mode 1 at 100 power, the reactor was manually tripped due to the loss of one of the main feed pumps. The trip was not complex, with all systems responding normally post-trip. No equipment was inoperable prior to the event that contributed to the event or adversely impacted plant response to the scram. Operations responded and stabilized the plant. Decay heat is being removed by Auxiliary Feedwater through the steam dumps to the condenser. Unit 2 is not affected. An automatic actuation of the Auxiliary Feedwater System (AFW) also occurred. The AFW auto-start is an expected response from the reactor trip. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results 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 55735 | 7 February 2022 15:49:00 | Vogtle | NRC Region 2 | W-AP1000 | The following information was provided by the licensee via telefone: A non-licensed contractor superintendent had a confirmed positive for alcohol during a for-cause fitness for duty test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified. |
| ENS 55679 | 29 December 2021 19:16:00 | Hatch | NRC Region 2 | GE-4 | This following information was conveyed by the licensee via phone and email: At 1552 EST on 12/29/21, with Unit 1 in Mode 1 at 90 percent power, the reactor was manually tripped due to reactor pressure perturbations. The cause of the reactor pressure perturbations is under investigation. Additionally, closure of (containment isolation valves) CIVs in multiple systems occurred during the trip as a result of reaching the actuation setpoint on reactor water level. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Reactor water level is being maintained via condensate / feedwater. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 2 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). It is also reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of CIVs. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 55552 | 29 October 2021 14:25:00 | Vogtle | NRC Region 2 | W-AP1000 | At 1010 EDT on October 29, 2021, Southern Nuclear Operating Company (SNC) determined a contractor supervisor attempted to subvert a random Fitness-for-Duty (FFD) test. The employee's badge has been confiscated. The NRC Resident Inspector has been notified. |
| ENS 55490 | 24 September 2021 17:27:00 | Farley | NRC Region 1 | Based upon a 10 CFR 21.21(b) transfer notification from General Electric Hitachi (GEH), Southern Nuclear Operating Company's (SNC) Joseph M. Farley Nuclear Plant (FNP) has determined there is evidence a Substantial Safety Hazard could have been created by the failure of the rivets installed on certain EC Trip Units if they were left uncorrected. These EC Trip Units are a subcomponent of all five (5) emergency diesel generator control panel supply breakers at FNP. This defect was identified and the components were repaired by GEH before being installed in the plant. These defective EC Trip Units never posed a challenge to the safe operation of FNP. The NRC Senior Resident Inspector at FNP has been notified. | |
| ENS 55462 | 15 September 2021 11:30:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | At 0658 CDT on 09/15/2021 a non work-related death occurred of a site employee. The individual was outside of the Radiological Controlled Area. This is a four-hour notification, non-emergency for a notification of other government agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). The NRC Resident Inspector has been notified. |
| ENS 55448 | 8 September 2021 08:40:00 | Hatch | NRC Region 2 | GE-4 | At 0159 EDT on 09/08/2021, the HPCI pump discharge valve failed to reopen during a valve surveillance, resulting in the HPCI system being declared INOPERABLE. HPCI does not have a redundant system; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). Reactor Core Isolation Cooling system and low pressure Emergency Core Cooling Systems were OPERABLE during this time. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 55420 | 20 August 2021 12:53:00 | Hatch | NRC Region 2 | GE-4 | A licensed operator failed a pre-access authorization test specified by the FFD testing program test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified. |
| ENS 55394 | 3 August 2021 13:18:00 | Hatch | NRC Region 2 | GE-4 | At 1026 EDT on 8/3/21, with Unit 1 in MODE 1 at 100 percent power, the reactor automatically tripped due to low reactor water level. The low reactor water level condition was due to a loss of both reactor feed pumps. The cause of the loss of feed pumps is under investigation. Additionally, the low reactor water level resulted in the automatic actuation of High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) systems, and Containment Isolation Valves (CIVs) in multiple systems. All safety systems responded normally. Operations responded and stabilized the plant. Reactor water level is being maintained via RCIC system. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 2 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). It is also reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the HPCI and RCIC systems and CIVs. There was no impact on the health and safety of the public or plant. The Licensee notified the NRC Resident Inspector. The Unit will proceed to Mode 4 while the cause of the loss of feed pumps is under investigation. |
| ENS 55365 | 20 July 2021 13:06:00 | Farley | NRC Region 2 | Westinghouse PWR 3-Loop | A non-licensed employee supervisor had a confirmed positive for alcohol 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 55328 | 25 June 2021 15:27:00 | Vogtle | NRC Region 2 | W-AP1000 | The following is a synopsis of information received via E-mail: The individual informing the Commission is Michael J. Yox, 7825 River Road, Waynesboro, GA 30830. The activities which fail to comply include construction processes including, installation of some electrical and mechanical commodities, and control of measuring and test equipment at the Vogtle 3 and 4 construction project. The primary construction firm for the Vogtle 3 and 4 construction project is Bechtel Power Corporation (Bechtel). This report is being provided based on construction nonconformances including, installation of some electrical and mechanical commodities, and control of measuring and test equipment for Vogtle Units 3 and 4. The nonconformances affect cable separation and other raceway structural elements. The extent of condition for the measuring and test equipment issue is under evaluation and may impact additional safety-related work. The identified construction nonconformances are a small fraction of the overall structures and components. There is no specifically identified substantial safety hazard (SSH) for these nonconformances. The nonconformances identified affect some safety-related components and based on this it was conservatively judged that the issues could be related to an SSH. These issues were discovered while the facility is under construction. The identified conditions will be corrected prior to completion of the facility. The evaluation for this report was completed on June 24, 2021. As stated above, there are no specifically identified basic components that have been identified to contain a defect for Vogtle Units 3 and 4. The nonconformances identified affect some safety-related components and based on this it was conservatively judged that these conditions involve a failure to comply that could be related to an SSH. The corrective action which has been, is being, or will be taken include: Comprehensive extent-of-condition reviews and correction of identified conditions are being conducted. The actions to identify and resolve the nonconforming conditions are in process and will be completed in accordance with the site corrective action program. Bechtel, and other subcontractors as needed, will implement actions to correct the identified conditions and ensure that processes are in place to avoid future occurrences. Southern Nuclear Operating Company (SNC) is the organization responsible for ensuring Bechtel and the other subcontractors complete the required actions to correct the nonconforming conditions and ensuring that processes are in place to avoid future occurrences. |
| ENS 55303 | 11 June 2021 18:06:00 | Hatch | NRC Region 2 | GE-4 | At 1710 EDT on June 11, 2021, a Technical Specification required shutdown was initiated at Plant Hatch Unit 1. Technical Specification Condition 3.4.4.B unidentified LEAKAGE increase not within limits, was entered due to a greater than 2 gpm increase in unidentified LEAKAGE within the previous 24 hour period in MODE 1. This specification was entered on June 11, 2021, at 1615 EDT with a REQUIRED ACTION to restore leakage increase within limits within 4 hours. This REQUIRED ACTION could not be completed within the COMPLETION TIME; therefore, a Technical Specification required shutdown was initiated, and this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(i). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
Upon further review of the leakage rates, it was determined that at 1900 EDT on 6/11/2021 the drywell floor drain unidentified leakage increased greater than 2 gpm within the previous 24 hours while in MODE 1. Technical Specification (TS) 3.4.4.B was entered to reduce leakage increase to within limits within 4 hours. At 2000 EDT on 6/11/2021 unidentified leakage was reduced below the 2 gpm increase within the previous 24 hours due to actions taken to lower reactor power and pressure. Therefore, the TS required shutdown per TS 3.4.4.C was not applicable. Thus Event Report 55303 is being retracted. The NRC resident has been notified of the retraction. Notified R2DO (Miller). |
| ENS 55188 | 12 April 2021 09:17:00 | Hatch | NRC Region 2 | GE-4 | At 2320 EST on 02/17/2021, with Unit 2 in Mode 5 at zero percent power, an actuation of the Group 2 containment isolation logic occurred on the inboard valves. The reason for the actuation was most likely due to air entrapment in reactor water level sensing lines following maintenance. Group 2 inboard isolation valves in the drywell floor and equipment drain system and the fission product monitor system automatically isolated as designed. As a corrective action, the variable leg and reference leg of the instrumentation were backfilled with water to ensure all air was removed from the line. This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that results in an invalid actuation of the Group 2 containment isolation system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 55187 | 12 April 2021 09:17:00 | Hatch | NRC Region 2 | GE-4 | At 2323 EST on 02/12/2021, with Unit 2 in Mode 5 at zero percent power, an actuation of the Group I containment isolation logic occurred during fluid flushing of turbine stop valves. The reason for the actuation was due to a maintenance activity resulting in turbine stop valve movement with no condenser vacuum which is a Group I isolation signal. Two Group I isolation valves, 2B31F019 and 2B31F020, reactor water sample valves, automatically isolated as designed when the system actuation signal was received. The other Group I valves had already been removed from service as part of the refueling outage schedule. This event is being reported in accordance with 10 CFR 50.73(a)(2)(iv)(A) as an event that results in an invalid actuation of the Group I containment isolation system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 55185 | 9 April 2021 16:08:00 | Vogtle | NRC Region 2 | W-AP1000 | A contract employee supervisor had a confirmed positive for illegal drugs during a random fitness-for-duty test. The employee's access to the plant had been terminated. |
| ENS 55055 | 3 January 2021 08:33:00 | Vogtle | NRC Region 2 | Westinghouse PWR 4-Loop | At 1414 EST on 12/31/2020, a planned maintenance outage commenced on the Vogtle 1and 2 Seismic Monitoring System. The work was to address abnormal indications on the uninterruptable power supply, and was scheduled for an eight (8) hour duration. During the restoration activities, the system did not respond properly and has remained Non-Functional. Compensatory measures for seismic event classification were implemented in accordance with Vogtle procedures prior to removing the system from service. Based upon the troubleshooting conducted, the system is not expected to be restored within 72 hours from the start of the planned outage. 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 Seismic Monitoring System is the method for evaluating that an Operational Basis Earthquake (OBE) threshold has been exceeded following a seismic event in accordance with Initiating Condition 'Seismic event greater than OBE levels' and Emergency Action Level HU2. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. Compensatory measures implemented include having a phone number to call to verify if an earthquake has occurred. |
| ENS 54995 | 12 November 2020 21:14:00 | Vogtle | NRC Region 2 | Westinghouse PWR 4-Loop | At 1732 EST on November 12, 2020, with Unit 2 in Mode 1 and 100 percent power, the reactor automatically tripped due to a turbine trip. The trip was not complex with all systems responding normally post trip. Operations responded and stabilized the plant. Decay heat is being removed by the steam generators through the steam dumps into the condenser. Unit 1 is not affected. An automatic actuation of the Auxiliary Feedwater System (AFW) also occurred. The AFW auto-start is an expected response from the reactor trip. Due to the Reactor Protection System actuation while critical, this event is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B), as well as in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results 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 54963 | 21 October 2020 14:10:00 | Vogtle | NRC Region 2 | W-AP1000 | In accordance with 10 CFR 52.99(c)(2) as described in NEI 08-01, Industry Guideline for the ITAAC Closure Process Under 10 CFR Part 52, Vogtle Units 3 and 4 Construction is making this notification to the NRC for determining that Inspections, Tests, Analyses and Acceptance Criteria (ITAAC) 2.3.05.13a.ii (Index No. 344) for Unit 4 requires additional actions to restore the completed status. The ITAAC Closure Notifications for Unit 4 ITAAC 344 was submitted on July 22, 2020 (ML20204B029). On October 19, 2020, it was determined that maintenance activities for the Unit 4 Polar Crane auxiliary hoist holding brake used a different approach for Post Work Verification (PWV) than the original test described in the ICN (ITAAC Closure Notification) for ITAAC 344. The alternate PWV used a test method that is standard industry practice and in accordance with ASME B30.2 to demonstrate that the Acceptance Criteria was met. An ITAAC Post Closure Notification will be submitted in accordance with 10 CFR 52.99(c)(2) and NEI 08-01. The 10 CFR 52.99(c)(4) All lTAAC Complete Notification has not been submitted for VEGP (Vogtle Electric Generating Plant) 4. The NRC Resident Inspector has been notified. |
| ENS 54864 | 28 August 2020 00:00:00 | Vogtle | NRC Region 2 | W-AP1000 | In accordance with 10 CFR 52.99(c)(2), as described in NEI 08-01, 'Industry Guideline for the ITAAC Closure Process Under 10 CFR Part 52,' Vogtle Units 3 and 4 Construction is making this notification to the NRC for determining that Inspections, Tests, Analyses and Acceptance Criteria (ITAAC) 2.5.02.07a (Index No. 534) and ITAAC 2.5.02.07e (Index No. 538) for both units require additional actions to restore their completed status. The ITAAC Closure Notifications for ITAAC 534 were submitted on March 31, 2017 (Unit 3 ML17093A286, Unit 4 ML17093A535). The ITAAC Closure Notifications for ITAAC 538 were submitted on November 30, 2016 (Unit 3 ML16351A350, Unit 4 ML16351A334). On August 26, 2020, it was determined that a design change, issued for several Protection and Safety Monitoring System (PMS) isolation barrier assemblies (ISBs), materially altered the basis for determining that the ITAAC 534 and ITAAC 538 Acceptance Criteria were met. The modified ISBs will require testing per IEEE 384-1981, Standard Criteria for Independence of Class 1E Equipment and Circuits, to demonstrate that the Acceptance Criteria is met. System function is not required while the plant is under construction. ITAAC Post Closure Notifications in accordance with 10 CFR 52.99(c)(2) will be submitted following completion of corrective actions. The 10 CFR 52.99(c)(4) All ITAAC Complete Notification has not been submitted for VEGP ((Vogtle Electric Generating Plant)) 3 and 4. The NRC Resident Inspector has been notified.
Upon successful completion of the work to correct the identified impact to ITAAC 534, it has been determined there was no material impact to ITAAC 538. Confirmation was made that the credible fault only affected PMS to PLS analog ISBs and not PMS to PLS relay isolation ISBs. It was also confirmed that the relay isolation ISB testing and qualification summary information was unaffected by the modifications made to the analog ISBs to correct the credible fault scenario condition. Resolution of the credible fault scenario did not result in modifications to the relay isolation ISBs which are the subject of ITAAC 538. Therefore, the ITAAC Closure Notifications submitted for ITAAC 538 on November 30, 2016 (Unit 3 ML16351A350, Unit 4 ML16351A334) continue to be valid and ITAAC Post Closure Notifications are not required. The licensee has notified NRC Region 2. Notified R2DO (Miller) and NRR Vogtle Project Office (via email). |