Semantic search
| Entered date | Site | Region | Reactor type | Event description | Topic | |
|---|---|---|---|---|---|---|
| ENS 57282 | 21 August 2024 19:30:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via fax and phone: At 1200 EDT on 8/21/2024, with Millstone unit 3 in mode 1 at 100 percent power, it was discovered that the secondary containment boundary was inoperable while maintenance activities on the system were in progress. Therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(C) and (D). There is no impact on the health and safety of the public and plant personnel. The NRC Resident Inspector has been notified. Unit 3 continues to operate in mode 1 at 100 percent power with actions in progress to restore the system to operable within the technical specification allowed outage time. There has been no impact to unit 2, which remains at 100 percent power. The state of Connecticut and local towns were notified. | |
| ENS 57158 | 2 June 2024 19:22:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: Surry Unit 1 reactor automatically tripped at 1708 EDT on 6/2/24 due to a turbine trip (with the reactor operating at greater than 10 percent reactor power). The turbine control system is currently under investigation. Reactor coolant temperature is being maintained via main steam dumps with main feedwater supplying the steam generators. All systems operated as required. The trip was uncomplicated and all control rods fully inserted into the core. There was no emergency core cooling system (ECCS) or auxiliary feedwater system actuation. Offsite power remains available. There is no impact to Surry Unit 2. This notification is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) for 4-hour notification of reactor protection system activation. The NRC Resident Inspector has been notified. There were no radiation releases, personnel injuries, or contamination events due to this event. | |
| ENS 57148 | 29 May 2024 08:50:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email and phone: On May 29, 2024, at 0624 EDT, Unit 1 automatically tripped from 100 percent power due to a negative rate trip. The unit has been stabilized in mode 3 at normal operating temperature and pressure. The reactor trip was uncomplicated and all control rods fully inserted into the core. This reactor protection system actuation is reportable per 10 CFR 50.72(b)(2)(iv)(B). The auxiliary feedwater pumps actuated as designed because of the reactor trip and is reportable per 10 CFR 50.72(b)(3)(iv)(A) for a valid engineered safety feature (ESF) actuation. Decay heat is being removed by the condenser steam dump system and Unit 1 is in a normal shutdown electrical lineup. Unit 2 was not affected by this event. The NRC Resident has been notified. | Negative Flux Rate Trip |
| ENS 57145 | 25 May 2024 15:26:00 | Millstone | NRC Region 1 | CE Westinghouse PWR 4-Loop | The following information was provided by the licensee by phone and email: A 50 ml bottle of vodka was found in the Unit 3 debris basket on the exterior of the intake structure. The bottle likely came from the ultimate heat sink (Niantic Bay) during normal backwash operations by the system that collects debris. Security has discarded the contraband. 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 bottle was found unsealed. | Ultimate heat sink Contraband |
| ENS 57105 | 3 May 2024 17:16:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 1630 EDT on 5/3/2024, the supervisor of nuclear site safety contacted the Area Director of OSHA to notify them of a workers foot injury requiring removal of a toe to the first joint. This was a 24 hr notification in accordance with 29 CFR 1904.39. The NRC Residents have been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The individual was not contaminated or working in a radiological area at the time of injury. | |
| ENS 57017 | 8 March 2024 13:59:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email and phone call: A non-licensed supervisor had a confirmed positive fitness for duty test. Unescorted access for the individual has been denied at all Dominion Energy sites. The NRC Senior Resident Inspector has been notified. | Fitness for Duty |
| ENS 56964 | 14 February 2024 15:35:00 | Kewaunee | NRC Region 3 | Westinghouse PWR 2-Loop | The following information was provided by the licensee email: At 1227 CST on February 14, 2024, OSHA was notified per 29 CFR 1904.39(a)(2) that an individual was transported to an offsite medical facility for treatment that required the individual to be admitted to the hospital. The individual was not working in a radiologically control area when the injury occurred. This event is being reported pursuant to 10 CFR 50.72(b)(2)(xi). The NRC Regional Inspector has been notified of this event. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The injured individual was working in an office environment prior to needing medical treatment. | |
| ENS 56774 | 3 October 2023 12:55:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: At 1154 EDT on 10/03/23, investigation into a boric acid indication was determined to be through a leak on a weld-o-let upstream of a pressurizer level transmitter isolation valve. Unit 2 is currently in MODE 6 with reactor coolant system (RCS) operational leakage limits not applicable. The leak is not quantifiable as it only consists of a small amount of dry boric acid at the location. The failure constitutes welding or material defects in the primary coolant system that are unacceptable under ASME Section XI. Therefore, this is a degraded condition reportable under 10 CFR 50.72(b)(3)(ii)(A). This condition does not affect the health and safety of the public or station employees. The Resident Inspector was notified. | Boric Acid |
| ENS 56743 | 18 September 2023 14:48:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: On 09/17/2023 at 2218 (EDT), Operations identified that the bearing cooling (BC) tower basin was overflowing. Earlier in the day, the BC tower was isolated as part of a planned maintenance evolution and the overflow condition was due to isolation valve leak-by. At 2255, the leak-by was corrected and stopped the overflow. Approximately 75 gallons may have been discharged to the lake from the overflow. The BC water was sampled by Chemistry and all chemical parameters were within VP DES (Virginia Pollutant Discharge Elimination System) limits. At 1420 on 09/18/23, a 24-hour notification was made to the Virginia Department of Environmental Quality (DEQ) in accordance with the North Anna VPDES permit. This issue is being reported per 10CFR50.72 (b)(2)(xi) due to the notification of other government agency. The NRC Resident Inspector was notified. | |
| ENS 56637 | 25 July 2023 16:06:00 | Millstone | NRC Region 1 | CE | The following information was provided by the licensee via email: At 0924 (EDT) on July 25, 2023, it was discovered that both trains of control room air conditioning system were simultaneously inoperable due to an inoperable control room envelope boundary. The boundary was restored at 0925 (EDT) on July 25, 2023. This condition is being reported as an eight-hour, non-emergency 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. There has been no impact to Unit 3 which remains at 100% power.
The licensee determined in a subsequent engineering evaluation of the conditions that existed at the time, that the access hatch being open did not have an adverse impact upon the control room emergency ventilation system and the control room envelopes boundary's ability to perform their safety function including: Radiation dose to the occupants did not exceed the licensing basis, design basis accident calculated value. Protection of control room occupants from hazardous chemicals and smoke. Therefore, this condition is not reportable and NRC Event EN56637 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector. Notified R1DO (Lally) | |
| ENS 56620 | 12 July 2023 12:49:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via email: At 0449 (EDT) on 7/12/2023, Millstone Unit 3 declared the 'B' train of the emergency core cooling system (ECCS) inoperable due to a degraded damper associated with the ventilation support system for the 'B' charging pump. At the time of this event, the 'A' train of service water was already inoperable due to planned maintenance on a breaker that would have prevented an 'A' service water valve powered from this breaker from closing on a safety signal. This configuration resulted in the possibility that the 'A' train of ECCS would not have been available to fulfill its design function under all postulated accident conditions. This event is being reported under 10 CFR 50.72(b)(3)(v)(B), '(any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (B) remove residual heat).' Subsequently, the 'A' train of service water was restored to operable at 0548 on 7/12/2023. Repairs and investigation continue on the 'B' train ECCS damper. The NRC resident has been notified. This event did not impact Millstone Unit 2. There was no impact to the public.
The following information was provided by the licensee via email: The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(B), via an 8-hour report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to remove residual heat. A subsequent engineering review of the conditions that existed at the time determined that, based on area temperature response, any impact on ventilation flows into and out of the `B' charging pump cubicle did not generate an observable change in the temperature trend. Based on this, it is concluded with reasonable assurance that the functional requirement of the support system was maintained and the `B' charging pump would have continued to perform its safety function until the `A' train of service water was restored to operable and as a result safety function was not lost. Therefore, this condition is not reportable and NRC Event Number 56620 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector." Notified R1DO (Bicket). | Time of Discovery |
| ENS 56618 | 11 July 2023 17:42:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: At 1530 (EDT) on 7/11/2023, North Anna Power Station notified the Virginia Department of Environmental Quality (DEQ) that a small volume of filtered/purified water potentially discharged into Lake Anna from a leak from a reverse osmosis unit. The leak did not follow the normal release path for discharge through outfall 013. No environmental impact associated with this leak was observed or would be expected because the water in question is cleaner than the lake water, and would have met all discharge requirements for outfall 013. The NRC Resident Inspector was notified. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). | |
| ENS 56610 | 6 July 2023 16:48:00 | Millstone | NRC Region 1 | CE | The following information was provided by the licensee via email: On July 6, 2023, at 1232 EDT, while operating in Mode 1 at 100 percent power, the supply check valve from the number 2 steam generator to the turbine driven auxiliary feedwater pump was determined during troubleshooting that it is not able to perform its isolation function. This failure would have resulted in the blowdown of both steam generators during a main steam line break in the number 2 steam generator main steam line upstream of the main steam isolation valves until the operators could isolate the faulted steam generator. Previous evaluation has determined that this condition constituted an unanalyzed condition that could impact containment pressure. There was no radioactive release to the environment. The steam line from the steam generator to the turbine driven auxiliary feedwater pump was isolated by use of a motor operated valve in the discharge line of the number 2 steam generator. There was no impact to Unit 3 which remains at 100 percent power. The NRC Senior Resident Inspector was notified. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety. | Unanalyzed Condition |
| ENS 56787 | 11 October 2023 11:00:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid specific system actuation of the North Anna Power Station Unit 1 Emergency Core Cooling System (ECCS). On 6/18/2023, a comparator card power supply associated with 1-CH-PC-1121A, charging pressure low-standby pump start signal comparator, failed and caused the `A' and `B' charging pumps to auto-start and the previously running `C' charging pump to trip and lock-out. This event is considered an invalid system actuation because the actuation was not initiated in response to actual plant conditions or parameters and was not a manual initiation. The ECCS pumps functioned as expected in response to the actuation. The `A' Charging pump was shut down in accordance with plant procedures following replacement of the comparator card. There was no impact on the health and safety of the public or plant personnel. The reportability requirement was determined beyond the 60-day notification requirement on 9/21/2023. The NRC Resident Inspector has been notified. | |
| ENS 56544 | 30 May 2023 08:34:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via email: At 0446 EDT on 5/30/2023, with Millstone Power Station Unit 3 operating at approximately 100 percent reactor power, an automatic reactor trip occurred due to a turbine trip caused by electrical protection. The reactor trip was uncomplicated and decay heat is being removed via steam dumps to the condenser. All systems responded as expected to the trip. Auxiliary feedwater actuated automatically as expected following the trip due to low-low levels in the steam generators. There was no risk to the public. There was no impact to Millstone Unit 2. This event is being reported as a four hour report under 10CFR50.72(b)(2)(iv)(B) as a condition that resulted in actuation of the reactor protection system while the reactor was critical, and as an eight hour report under 10CFR50.72(b)(3)(iv)(A) and 10CFR50.72(b)(3)(iv)(B) for actuation of the auxiliary feedwater system. The NRC Resident Inspector has been notified. | |
| ENS 56374 | 20 February 2023 17:07:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via fax: At 1618 EST on February 20, 2023, North Anna Power Station notified the Virginia Department of Environmental Quality (DEQ) that water discharged into Lake Anna following hydrostatic testing of tanks associated with a new on-site sewage treatment plant had exceeded the project's general permit (VAG83) pH value. Hydrostatic test water discharge activities to Lake Anna began on February 20, 2023 at 0900 EST. A pH sample was collected at 0955 EST on February 20, 2023 and determined to have a pH of 9.1 which exceeded the maximum permit pH of 9.0. Discharge ceased after the reading was collected. Approximately 354 gallons were discharged to Lake Anna. A follow-up ambient pH sample result of 7.8 was collected on February 20, 2023 at 1401 EST from Lake Anna in the vicinity of the discharge pipe. No evidence of dead fish, foam, or other negative environmental impacts were observed. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi) for 'Any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. Such an event may include an on-site fatality or inadvertent release of radioactively contaminated materials.'
The following is a summary of information provided by the licensee via telephone: The licensee called to correct the pH sample results from a pH of 9.1 to a pH of 9.93. Notified R2DO (Miller) via phone | Hydrostatic Fatality |
| ENS 56095 | 7 September 2022 15:06:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | A licensed employee had a confirmed positive for alcohol during a random fitness-for-duty test. Unescorted access for the individual has been denied at all Dominion Energy sites. | Fitness for Duty |
| ENS 56088 | 4 September 2022 20:30:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | At 1939 EDT, the North Anna Power Station Units 1/2 declared a Notice of Unusual Event (NOUE) under emergency declaration HU1.1 confirmed security event. Both units were unaffected by the event. The licensee exited the NOUE at 2036 EDT. | |
| ENS 56073 | 27 August 2022 12:13:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: At 0810 EDT on August 27, 2022, with Unit 2 at 27% power, the operating crew received an annunciator for a Turbine Trip Without Reactor Trip. At 0812 EDT, a report came in from the field of a fire in the north yard due to an "A" Main Transformer upper bushing failure. The station fire brigade was dispatched and offsite assistance was requested. However, at 0842 EDT the fire was put out, prior to needing the offsite assistance. No Emergency Action Level threshold was exceeded for this event. The switchyard is in a normal alignment for providing offsite power to Unit 2. At 1015 EDT, the Virginia Department of Emergency Management (VDEM) was notified of the event. Additionally, a notification to the Virginia Department of Environmental Quality will be made due to approximately 100 gallons of oil reaching the ground. As such, this issue is being reported per 10 CFR 50.72(b)(2)(xi) for "'Any event or situation for which a news release is planned or notification to other government agencies has been or will be made.' The NRC Resident Inspector was notified. | |
| ENS 55893 | 11 May 2022 18:12:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via email: A licensed operator had a confirmed positive for alcohol during a follow-up fitness-for-duty test. The employee's access to the plant is on hold in accordance with the licensee's fitness-for-duty policy. The licensee notified the NRC Resident Inspector. | Fitness for Duty |
| ENS 55873 | 3 May 2022 14:48:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: A non-licensed Dominion Energy supervisor had a confirmed positive for illegal drugs during a random fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector. | |
| ENS 55843 | 14 April 2022 11:18:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email: On April 14, 2022, at 0928 (EDT) hours, Unit 1 automatically tripped from 100 percent power during the control rod operability periodic test. The reactor trip occurred during the manipulation of the rod control mode selector switch as part of the rod operability testing. The Operations crew entered the reactor trip procedure and stabilized Unit 1 in Mode 3 at normal operating temperature and pressure. The reactor trip was uncomplicated, and all control rods fully inserted into the core. This reactor protection system actuation is reportable per 10 CFR 50.72(b)(2)(iv)(B). The Auxiliary Feedwater pumps actuated as designed because of the reactor trip and provide makeup flow to the steam generators. The automatic start of the Auxiliary Feedwater system is reportable per 10 CFR 50.72(b)(3)(iv) (A) for a valid actuation of an ESF (Engineered Safety Features) system. The Auxiliary Feedwater pumps were subsequently secured and returned to automatic. Decay heat is being removed by the condenser steam dump system. Unit 1 is in a normal shutdown electrical lineup. An investigation into the cause of the reactor trip is underway. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: There was no affect to Unit 2. Unit 2 is operating at 100 percent power. | |
| ENS 55828 | 7 April 2022 16:12:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone call: At 0909 EDT on 4/7/2022, it was determined that a security officer tested positive during a random fitness-for-duty test. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified. | |
| ENS 55576 | 14 November 2021 17:06:00 | Millstone | NRC Region 1 | CE | On November 14, 2021, at 1150 EST, while operating in Mode 1 at 100 percent power, the supply check valve from the Number 2 steam generator to the turbine driven auxiliary feedwater pump was determined during troubleshooting that it is not able to perform its isolation function. This failure would have resulted in the blowdown of both steam generators during a main steam line break in the Number 2 steam generator main steam line upstream of the main steam isolation valves until the operators could isolate the faulted steam generator. Previous evaluation has determined that this condition constituted an unanalyzed condition that could impact containment pressure. There has been no radioactive release to the environment. The steam lines from the steam generators to the turbine driven auxiliary feedwater pump have been isolated by use of a motor operated valve in the discharge line of the Number 2 steam generator. There has been no impact to Unit 3 which remains at 100 percent power. The NRC Senior Resident has been notified. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety. | Unanalyzed Condition |
| ENS 55570 | 10 November 2021 18:38:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | At 1515 EST on 11/10/21, approximately 89 gallons of PCB oil is unaccounted for from the Substation 'N' Transformer, located in the Owner Controlled Area. Transformer nameplate oil capacity is 569 gallons. Prior to removal of the original Substation 'N' Transformer, approximately 475 gallons of 10-CA-OIL (PCB Oil) was evacuated and stored by HEPACO (a licensee vendor). Approximately 5 gallons of oil is inaccessible to evacuate and remains in the original transformer. Below the transformer was evidence of oil leakage to the ground. The leakage appears to have been occurring over time, not as a result of a catastrophic failure. This condition is reportable to the Virginia Department of Environmental Quality (VA DEQ). The VA DEQ was notified of this condition at 1815 on 11/10/21. Cleanup activities are on-going. This event is reportable in accordance with 10CFR50.72(b)(2)(xi) for 'Any event or situation, related to the health and safety of the public or on-site personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made. Such an event may include an on-site fatality or inadvertent release of radioactively contaminated materials.' The licensee will be notifying the Louisa County administrator and has notified the NRC Resident Inspector.
Initial, unofficial, field testing performed by HEPACO indicated the oil released to the ground was PCB-Contaminated Oil. The official test results from the lab indicated that the oil is in fact not classified as PCB-Contaminated Oil. Therefore, this update is being made to EN55570 to clarify that the oil released to the environment was not PCB-Contaminated Oil. The licensee notified the NRC Resident Inspector and the VA DEQ of this update. Notified R2DO (Miller). | Fatality |
| ENS 55565 | 6 November 2021 13:03:00 | Millstone | NRC Region 1 | CE | During a Unit 2 refueling outage valve overhaul activity on the steam supply check valve from the number 2 steam generator to the turbine driven auxiliary feedwater pump, 2-MS-4B, the check valve was found with its disc separated from the disc arm. This failure would have resulted in the blowdown of both steam generators during a main steam line break in the steam generator number 2 main steam line upstream of the main steam isolation valves until the operators could isolate the faulted steam generator. On November 6, at approximately 1100 EDT evaluation determined that this condition constituted an unanalyzed condition that could impact containment pressure. There has been no radioactive release to the environment. The valve has been repaired. The check valve in the steam supply from the number 1 steam generator to the turbine driven auxiliary feedwater pump was inspected and found to be satisfactory. There has been no impact to Unit 3 which remains at 100% power. The Senior Resident has been notified. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety. | Unanalyzed Condition |
| ENS 55459 | 13 September 2021 23:47:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | On September 13, 2021, at 1822 EDT, an apparent non-compliance with 10 CFR 50, Appendix R, section III.G.2 (separation of redundant fire safe shutdown equipment) was identified. Specifically, it was determined that some Emergency Diesel Generator (EDG) cables may be susceptible to a hot short/spurious operation to the close circuit. A spurious closure of the emergency bus normal supply breakers after the EDG is powering the bus could result in non-synchronous paralleling, EDG overloading, or EDG output breaker tripping due to faulted power cable from normal supply breaker. The spurious closure of the normal supply breakers is not currently addressed in the Appendix R Report or previous Multiple Spurious Operations (MSO) analysis. This condition is associated with the Appendix R safe-shutdown function of the Emergency Power System. The Emergency Power System is considered operable but not fully qualified for its safety-related design function. The following fire areas are impacted: 1) Fire Area 13, Unit 1 Normal Switchgear Room 2) Fire Area 46, Unit 1 Cable Tray Room 3) Fire Area 3, Unit 1 Emergency Switchgear and Relay Room 4) Fire Area 2, Unit 2 Cable Vault and Tunnel Until this condition is analyzed, Surry has implemented mitigating actions in the above fire areas. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B). This is also reportable as a 60-day written report pursuant to 10 CFR 50.73(a)(2)(ii)(B). This event was entered into the licensee's Corrective Action Program as CR (condition report) 1180502. The NRC Resident Inspector has been notified of this event. Mitigating actions include posting fire watches in the affected areas. | Safe Shutdown Unanalyzed Condition Multiple Spurious Operation |
| ENS 55457 | 12 September 2021 22:41:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | On September 12, 2021, at 1728 EDT, with Unit 1 in Mode 5 (Cold Shutdown) while performing inspections of the North Anna Power Station Unit 1 reactor vessel head flange area, a weld leak was identified on the reactor vessel flange leak-off line that connects to the flange between the inner and outer head o-rings. Entered TRM 3.4.6 Condition B for ASME Code Class 1,2, and 3 components. With known leakage past the inner head o-ring, this condition is reported since the fault in the tubing is considered pressure boundary (Reactor Coolant System) leakage. This event is reportable in accordance with 10 CFR 50.72(b)(3)(ii)(A) for any event or condition that results in the condition of the nuclear power plant, including its principle safety barriers, being seriously degraded. The NRC Resident has been notified.
The condition identified in EN 55457, pursuant to 10 CFR 50.72 (b)(3)(ii)(A) has been evaluated, and has been determined not to be Reactor Coolant System (RCS) pressure boundary leakage. As such, the 8-hour report is being retracted, as it is not an event or condition that results in, 'the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded.' The leakage was subsequently determined to be in a tubing connection downstream of the reactor vessel inner O-ring. Leakage past a seal or gasket is not considered to be pressure boundary leakage, as defined by Technical Specifications. The NRC Resident Inspector has been notified. Notified R2DO (Miller) | Pressure Boundary Leakage |
| ENS 55375 | 22 July 2021 20:28:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | On July 20, 2021, at 1707 EDT, an apparent non-compliance with 10 CFR 50, Appendix R, section III.G.2 (separation of redundant fire safe shutdown equipment) was identified. This issue was initially categorized as not affecting train separation or the ability of the equipment to perform their Design Basis functions. The original concern was entered into the licensee's Corrective Action Program as CR1177199. Subsequently, on July 22, 2021, at 1751 EDT, a further review of the affected control circuits for the Unit 1 and Unit 2 Emergency Diesel Generator (EDG) output breakers and emergency bus feeder breakers identified a concern that breaker position interlocks routed to or through non-safety related components or spaces may affect the ability to provide emergency power on the affected unit due to impacts on the control power circuits during an Appendix R fire associated with a loss of offsite power. The following are the affected fire areas: - Unit 1 and Unit 2 Turbine Buildings - Unit 1 and Unit 2 Cable Spreading Rooms - Unit 1 and Unit 2 Normal (307) Switchgear Rooms This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B). This is also reportable as a 60-day written report pursuant to 10 CFR 50.73(a)(2)(ii)(B). This event was entered into the licensee's Corrective Action Program as CR 1177399. The NRC Resident Inspector has been notified of this event. | Safe Shutdown Unanalyzed Condition |
| ENS 55299 | 9 June 2021 15:02:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | At 1115 EDT on June 9, 2021, during a siren activation test, a loss of the capability to activate the sirens from both Surry local activation sites was identified. The Virginia EOC was participating in the activation test and is aware of the issue and notified the local government authorities in the Surry EPZ of the situation. The NRC Resident has been notified of this issue. The station telecommunications department has been contacted and is aware of the issue. In the event that a radiological emergency should occur at the Surry Power Station, Primary Route Alerting procedures will be put in use by the local jurisdictions. This report is being made in accordance with 10 CFR 50.72(b)(2)(xi) and 10 CFR 50.72(b)(3)(xiii) due to notification of other state and local government agencies of the failure of the Alert & Notification system for Surry.
Surry Power Station Event Notification 55299 is being retracted based upon further evaluation. Surry has three localities (State SAU, James City, and Surry County) with access to the redundant activation trains (primary and backup systems). The actuation tests only one primary and one backup activation panel at two localities, only primary at the State SAU (Situational Awareness Unit) and back up at James City County were tested. Follow-up telecom and vendor investigation revealed that the primary server was functional from James City County that would have actuated all 71 sirens; Consequently, it was concluded that all of the sirens were fully functional from the James City primary system and there was no loss of all sirens as originally reported on 6/9/2021 (EN 55299). EN 55299 also contained a 4-hour Offsite Notification per 10 CFR 50.72(b)(2)(xi) that is unaffected. The NRC Resident Inspector has been notified. Notified R2DO (Miller). | Siren |
| ENS 55239 | 6 May 2021 14:00:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | On May 6, 2021 at 1223 (EDT), Unit 1 was manually tripped from 60 percent power due to degrading main condenser vacuum. Unit 1 was in the process of decreasing power due to increased secondary sodium levels identified earlier in the day. The Operations crew entered the reactor trip procedure and stabilized Unit 1 in Mode 3 at normal operating temperature and pressure. All control rods fully inserted into the core following the reactor trip. This reactor protection actuation is reportable per 10 CFR 50.72(b)(2)(iv)(B). Auxiliary Feedwater pumps actuated as designed as a result of the reactor trip and provided makeup flow to the steam generators. The automatic start of the Auxiliary Feedwater pumps is reportable per 10 CFR 50,72(b)(3)(iv)(A) for a valid actuation of an ESF (Engineered Safeguards Features) system. Decay heat is being removed by the condenser steam dump system. The electrical system is in normal lineup for shutdown conditions. There was no effect on Unit 2 operation. The NRC resident inspector has been notified. | |
| ENS 55035 | 14 December 2020 15:00:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | At 2214 EST on 12/12/20, Surry Power Station personnel identified leakage from the Unit 2 Refueling Water Storage Tank (RWST) Cooling System to the ground. Leakage was estimated to be greater than 100 gallons and tritium concentration determined to be 4.5E07 picocuries per liter (pCi/L), requiring report in accordance with the industry voluntary groundwater protection program. As such, at 1450 EST on 12/14/2020, the Surry County Administrator, NRC Resident, Virginia Department of Health, Virginia Department of Emergency Management, and Virginia Department of Environmental Quality were notified of this release to the environment. Due to the offsite agency notifications, this 4-hour, non-emergency report is being made in accordance with 10 CFR 50.72(b)(2)(xi). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. | |
| ENS 54988 | 8 November 2020 10:10:00 | Millstone | NRC Region 1 | CE Westinghouse PWR 4-Loop | Millstone Units 2 & 3 declared an Unusual Event at 0921 EST after an earthquake was felt onsite. The earthquake monitoring instrumentation did not actuate, and there were no station system actuations. No damage has been detected at this time. Millstone has initiated their Abnormal Operating Procedure for an earthquake and performing station walkdowns. The State of Massachusetts has been notified. The Waterford Police and U.S. Coast Guard have contacted the station. The NRC resident has been notified. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
At 1510 EST on November 8, 2020, Millstone Units 2 & 3 exited the Unusual Event due to the earthquake following plant walkdowns that revealed no damage to plant structures, systems, or components. Station and System walkdowns identified no issues due to the earthquake. Millstone notified the State and local authorities, and the NRC Resident Inspector. Notified R1DO (DeFrancisco), IRD (Grant), NRR (Nieh), R1RA (Lew), NRR EO (Miller), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email). | Earthquake |
| ENS 55026 | 10 December 2020 10:58:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | This 60-day telephone notification is being submitted in accordance with paragraphs 10 CFR 50.73(a)(1) and 50.73(a)(2)(iv)(A) to report an invalid actuation of the 'B' train High Head Safety Injection Pump (3SIH*P1B), the 'B' train Low Pressure Safety Injection Pump (3RHS*P1B) and four Steam Generator Blowdown Containment isolation valves at Millstone Nuclear Power Station Unit 3. At 1908 EST on November 6, 2020, with Unit 3 in Mode 3, a partial invalid actuation of 'B' train Emergency Core Cooling System (ECCS) components occurred. The 'B' train SIH pump and the 'B' train RHS pump had started, and ran successfully on recirculation. Four Steam Generator Blowdown Containment isolation valves also closed. Due to this condition the 'B' Emergency Diesel Generator and the 'B' Emergency Generator Load Sequencer (EGLS) were declared inoperable and the required Technical Specification action statements were entered. Troubleshooting determined that this actuation was caused by a failure of one of the circuit boards in the 'B' train EGLS that caused a partial 'B' train 'SIS only' signal. Other 'B' Train components received the 'SIS only' signal but did not start because they were already running or were a backup to an already running component. Troubleshooting discovered a failed NAND gate on the 'B' Train EGLS XA93 circuit card. The card was replaced, retested, and the Technical Specification action statements were exited. The pumps and valves responded in accordance with plant design. No other equipment was affected during this event. There were no safety consequences or impacts on the health and safety of the public. The event was entered into the station's corrective action program. The actuation was not due to actual plant conditions or parameters meeting design criteria for an ECCS actuation. Therefore, this is considered an invalid actuation. The NRC Resident Inspector was notified. | |
| ENS 54927 | 2 October 2020 12:35:00 | Millstone | NRC Region 1 | At 0945 hours (EDT) on 10/02/2020, with Millstone Unit 3 in Mode 4, Operations discovered a door in the Secondary Containment boundary blocked open. Investigation determined the door was blocked open at 1842 (EDT) on 10/01/2020, rendering Secondary Containment inoperable. The door was closed at 1002 ((EDT) on 10/02/2020), restoring Secondary Containment to operable status. Since Secondary Containment was rendered inoperable, Dominion Energy is reporting this as a condition that could have prevented the fulfillment of the safety function to control the release of radioactive material and mitigate the consequences of an accident. This condition is being reported as an eight hour report pursuant to 10 CFR 50.72 (b)(3)(v)(C) and (D). There was no release of radioactivity to the public. The NRC Senior Resident Inspector has been notified. With the door blocked open, the plant was in a 24-hour shutdown action statement. The state of Connecticut and local towns were notified. | ||
| ENS 54921 | 29 September 2020 10:21:00 | North Anna | NRC Region 2 | A non-licensed Dominion Energy supervisor had a confirmed positive for illegal drugs during a random fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector. | ||
| ENS 54816 | 4 August 2020 22:43:00 | Millstone | NRC Region 1 | EN Revision Imported Date : 8/20/2020 BOTH SERVICE WATER HEADERS DECLARED INOPERABLE On 8/4/20, at 1745 EDT, Millstone Unit 2 entered technical specification (TS) 3.0.3 due to both service water headers being declared inoperable because strainer differential pressures (D/Ps) were greater than 9 psid. The high service water strainer D/P was the result of heavy debris impingement caused by tropical storm Isaias. To reduce heat loads and service water flow, Unit 2 reduced power to 75 percent. One service water header was restored to operable at 1816 EDT, at which time TS 3.0.3 was exited. At 1843 EDT both service water headers were declared operable. The NRC Resident Inspector has been notified.
The purpose of this call is to retract a report made on August 4, 2020, NRC Event Number EN 54816 describes a condition at Millstone Power Station Unit 2 (MPS2) in which both trains of service headers were declared inoperable due to service water strainer differential pressures greater than 9 psid. The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(A), (B) and (D) via an 8 hour prompt report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to shutdown the reactor and maintain it in a safe shutdown condition, remove residual heat and mitigate the consequences of an accident. Upon further review, MPS2 determined that there was no loss of safety function. An engineering evaluation supports the conclusion that a strainer differential pressure of 16 psid would not challenge the system flow distribution during worst case conditions. The evaluation also demonstrates that flowrates on both headers were observed to be unaffected during the timeframe of the high strainer differential pressure conditions. Therefore, both service water headers would have provided the required flows to perform their safety function. Therefore, this condition is not reportable and NRC Event Number EN 54816 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector. Notified R1DO (Greives). | Safe Shutdown Time of Discovery | |
| ENS 54738 | 5 June 2020 10:39:00 | Millstone | NRC Region 1 | EN Revision Imported Date : 10/6/2020 CONTROL ROOM BOUNDARY DOOR FAILURE On June 5, 2020, at 0320 (EDT) a loss of control room envelope (CRE) was declared inoperable due to failure of door 204-36-007. The door was repaired at 0322 (EDT), restoring the CRE to operable. The NRC Resident Inspector, state, and local authorities were notified.
The purpose of this call is to retract a report made on June 5, 2020, NRC Event Number EN54738. NRC Event Report number EN54738 describes a condition at Millstone Power Station Unit 2 (MPS2) in which a control room envelope boundary door was discovered to not be able to fully close due to the latching mechanism being stuck in the extended position. The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(D) via an 8 hour prompt report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. Upon further review, MPS2 determined that there was no loss of safety function. An engineering evaluation determined that even with the control room boundary door unable to be fully closed due to the latching mechanism being stuck in, the extended position, control room air in-leakage would not have been sufficient to prevent the control room emergency ventilation system from performing its safety function. Therefore, this condition is not reportable and NRC Event Number EN54738 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector. Notified R1DO (Dimitriadis).
The purpose of this call is to provide an update to the retraction for a report made on June 5, 2020, NRC Event Number EN54738. The retraction being updated was made on 7/9/2020 at 1443 hours. NRC Event Report number EN54738 describes a condition at Millstone Power Station Unit 2 (MPS2) in which a control room envelope boundary door was discovered to not be able to fully close due to the latching mechanism being stuck in the extended position. The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(D) via an 8 hour prompt report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident (the Control Room Envelope). A subsequent engineering evaluation of the conditions that existed at the time, determined that the inability of the control room boundary door to fully close due to the latching mechanism being stuck in the extended position did not have an adverse impact upon the ability of the CRE to perform its safety function. The CRE remained operable throughout this event, and the ventilation system would have performed its safety function. Therefore, this condition is not reportable and NRC Event Number EN54738 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector. Notified R1DO (Lally). | Time of Discovery | |
| ENS 54727 | 26 May 2020 15:55:00 | Surry | NRC Region 2 | A contract foreman had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector. | Fitness for Duty | |
| ENS 54663 | 13 April 2020 19:33:00 | Millstone | NRC Region 1 | At 1550 EDT on 4/13/2020, with Millstone Power Station Unit 3 operating at approximately 82 percent reactor power, an automatic reactor trip occurred following a turbine trip due to low condenser vacuum caused by the trip of multiple circulating water pumps. Due to the loss of the circulating water pumps, decay heat removal was established by the steam generator atmospheric dump valves. All other systems responded as expected to the trip. Auxiliary feedwater actuated automatically as expected following the trip due to low-low levels in the steam generators. There was no risk to the public. There was no impact to Millstone Unit 2. The Senior Resident Inspector has been informed. This event is being reported as a four hour report under 10 CFR 50.72(b)(2)(iv)(B) as a condition that resulted in actuation of the reactor protection system while the reactor was critical, and as an eight hour report under 10 CFR 50.72(b)(3)(iv)(A) and 10 CFR 50.72(b)(3)(iv)(B) for actuation of the auxiliary feedwater system. The licensee also notified the state of Connecticut, the Connecticut Department of Energy and Environmental Protection, and the city of Waterford. | ||
| ENS 54652 | 9 April 2020 03:37:00 | North Anna | NRC Region 2 | On April 9, 2020 at 0100 EDT, while performing a containment walkdown due to a small increased Reactor Coolant System (RCS) unidentified leakage, a leak was identified on the 'A' Reactor Coolant Pump (RCP) seal injection piping. The source of the leakage cannot be isolated and is considered RCS pressure boundary leakage. At that time, Condition B of Technical Specification (TS) LCO 3.4.13, 'RCS Operational Leakage' was entered due to pressure boundary leakage. TS 3.4.4 'RCS Loops - Mode 1 and 2' and Technical Requirement (TR) 3.4.6 'ASME Code Class 1, 2, and 3 Components' are also applicable. Unit 2 is projected to be taken to Mode 5 for repairs. This event is reportable in accordance with 10 CFR 50.72(b)(2) for 'Initiation of plant shutdown required by Technical Specifications' and 10 CFR 50.72(b)(3)(ii)(A) for 'Any event or condition that results in the condition of the nuclear power plant, including its principle safety barriers, being seriously degraded.' The licensee notified the NRC Resident Inspector. There is no effect on Unit 1 | Pressure Boundary Leakage Unidentified leakage | |
| ENS 54631 | 1 April 2020 19:11:00 | Millstone | NRC Region 1 | On April 1, 2020, at 1625 EDT, Milllstone Unit 3 was in Mode 1, at 100 percent power, when an automatic reactor trip occurred following a main generator trip. The cause was due to a circuit fault between the main generator breaker and the offsite switchyard. The reactor trip was not complicated and the reactor remains stable in Mode 3. One of the two offsite electrical sources remain inoperable with an investigation of the circuit fault underway. Decay heat removal is maintained by the main condenser. There was no effect on Unit 2. The NRC Resident Inspector was notified. The licensee notified State and local government agencies. | ||
| ENS 54457 | 27 December 2019 07:53:00 | Millstone | NRC Region 1 | This is a synopsis of initial information received via phone: On December 27, 2019, at 0705 EST, while Unit 2 was at 100 percent (Mode 1), the 'A' Main Feedwater Pump tripped due to an unknown cause. The reactor was manually tripped and is currently at zero (0) percent power (Mode 3). Decay heat is being removed via Auxiliary Feedwater. The 'B' Feedwater pump is operable. There was no impact on Unit 3. The licensee notified the NRC Resident Inspector. Additionally, Connecticut Department of Environmental Protection, Waterford Dispatch, and East Lyme Emergency Management Division will be notified.
This is an update to NRC Event Number 54457. At 0704 EST, on 12/27/2019, with Millstone Unit 2 operating at 100 percent power, operators inserted a manual reactor trip. The trip was initiated due to a trip of the 'A' Main Feedwater Pump. The Auxiliary Feedwater System (AFW) automatically actuated as required. All control and shutdown rods fully inserted. All safety systems responded as designed. No primary or secondary safety valves actuated during or after the transient. Unit 2 is currently stable at normal operating pressure and temperature in Mode 3, Hot Standby. Reactor Coolant System (RCS) temperature is being maintained by the steam dump system with all Reactor Coolant Pumps (RCPs) in service. Main Feedwater has been secured, and Auxiliary Feedwater is in service. The electrical system is in normal alignment. There was no impact on Unit 3. There was no impact to the health and safety of the public or plant personnel. Due to Reactor Protection System (RPS) actuation while critical, this event was reported as a four hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B); and an eight hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the AFW system. The licensee will notify the NRC Resident Inspector of the update. Notified R1DO (Cherubini). | ||
| ENS 54449 | 17 December 2019 21:10:00 | Millstone | NRC Region 1 | At 1929 EST, on 12/17/19, Millstone Unit 3 began preparations for shutting down the reactor as the 'A' Emergency Diesel Generator (EDG) could not be restored to operable status within the 14-day outage time, requiring a Technical Specification (Tech Spec) shutdown. Per Tech Spec 3.8.1.1., the reactor must be in Hot Standby in six (6) hours, and Cold Shutdown within the following 30 hours. Hot Standby is estimated by midnight, and Cold Shutdown by 1800 EST on 12/18/19. All other safety and shutdown systems are operable. Decay heat removal will be through the Shut Down Cooling and Residual Heat Removal systems. There was no impact to Unit 2. There was no impact to the health and safety of the public or plant personnel. The licensee notified the state of Connecticut, Waterford County, and the NRC Resident Inspector. | ||
| ENS 54437 | 11 December 2019 15:06:00 | Surry | NRC Region 2 | On December 11, 2019, at 1356 EST, it was concluded that certain safety-related equipment is vulnerable to design basis tornado missiles which could render the equipment inoperable and not able to perform its design function. This applies to the following Technical Specification equipment: 1. Component cooling water piping for the 'A' spent fuel cooling water system heat exchanger. This heat exchanger is vulnerable to a horizontal missile traveling through the roll-up door, which would challenge operability of the Technical Specification required component cooling system equipment. 2. All three (3) emergency service water pumps and their diesel fuel oil supply tank. The emergency service water pumps and diesel fuel oil tank are vulnerable to a horizontal missile penetrating the missile screens. 3. Certain component cooling water system pump discharge piping is vulnerable from a vertical missile penetrating the auxiliary building roof. 4. The Unit 1 auxiliary feedwater (AFW) system pumps and the pump suction and discharge piping are vulnerable to a missile traveling through the screens on the sides and roof of the main steam valve house. This vulnerability also exists for the Unit 2 AFW. This condition puts Unit 1 and 2 into Technical Specification 3.01 which requires the units to be in hot shutdown within 6 hours and in cold shutdown within the following 30 hours. The NRC Resident Inspector has been notified. | Tornado Generated Missile | |
| ENS 54401 | 21 November 2019 04:02:00 | Surry | NRC Region 2 | At 2144 EST, on 11/20/2019, all three auxiliary feedwater pumps for Unit 2 were declared Inoperable due to check valve leakage causing the turbine driven auxiliary feedwater pump to rotate backwards and subsequently trip. At this time, two of the Unit 1 motor driven auxiliary feedwater pumps were still able to provide cross-tied feedwater in the event of a design basis accident. At 2203 EST, the two motor driven auxiliary feedwater pumps on Unit 2 were declared operable once the discharge isolation valves for the turbine driven auxiliary feedwater pump were closed, thus preventing backflow through the turbine driven auxiliary feedwater pump and ensuring forward flow of the motor driven auxiliary feedwater pumps. This condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D) for an event or condition that could have prevented the fulfillment of a safety function. There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. Unit 2 is in a 72-hour LCO 3.6.F.1 for turbine driven auxiliary feedwater pump inoperability. | ||
| ENS 53909 | 3 March 2019 09:54:00 | North Anna | NRC Region 2 | At 0916 EST on March 3, 2019, North Anna Unit 2 declared a Notice of Unusual Event under Emergency Action Level HU 2.1 (fire in/or restricting access to any table H-1 area not extinguished within 15 minutes of control room notification or verification of a control room alarm). At 0906 the control room received a heat sensor alarm for the Unit 2, Reactor Coolant Pump motor cube. The fire brigade was dispatched to the scene where they found no indication of fire, no smoke and no fire damage. There were no actuations associated with the alarm and no redundant indications of fire. There was no effect on plant equipment and no indications of RCS leaks. The site determined that the alarm was invalid and terminated the NOUE. Unit 2 is in a stable condition and in a normal electrical lineup. Offsite support was not requested. The NRC Resident Inspector, State, and local authorities have been notified by the licensee. Notified R2RA (Haney), DNRR (Evans), IRD MOC (Grant), R4RDO (Rose), DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email). | ||
| ENS 53908 | 3 March 2019 00:13:00 | North Anna | NRC Region 2 | On March 2, 2019 at 2237 EST, North Anna Unit 2 reactor was manually tripped, while operating at approximately 12 percent power, due to degrading vacuum in the main condenser. The unit was in the process of a planned shutdown for refueling when condenser vacuum degraded to greater than 3.5 inches of mercury absolute. The operations crew entered the reactor trip procedure and stabilized the unit in Mode 3 at normal operating pressure and temperature. All control rods fully inserted into the core following the reactor trip. The reactor protection system actuation is reportable per 10 CFR 50.72(b)(2)(iv)(B). There were no ESF system actuations. Decay heat is being removed by the Steam Generator Pressure Operated Relief valves. Unit 2 is in a normal shutdown electrical lineup. The NRC Resident Inspectors have been notified. The Louisa County Administrator will be notified. | ||
| ENS 53752 | 25 November 2018 02:47:00 | Millstone | NRC Region 1 | EN Revision Text: LOSS OF CONTROL ROOM ENVELOPE DUE TO DOOR FAILURE On 11/24/18 at 2015 EST, a loss of Control Room Envelope (CRE) was declared due to failure of the control room boundary door, 204-36-008. (Abnormal Operating Procedure 8588A Mitigating Actions for Control Boundary Breach was implemented). The door was repaired at 2030 EST, restoring CRE to operable (status). A mechanical failure of the control room door latch prevented the door from closing. The licensee notified the NRC Resident Inspector.
The purpose of this call is to retract a report made on November 25, 2018, NRC Event Number EN53752. NRC Event Report number EN53752 describes a condition at Millstone Power Station Unit 2 (MPS2) in which a control room envelope boundary door was discovered to not be able to fully close due to the latching mechanism being stuck in the extended position. The condition was reported to the NRC pursuant to 10 CFR 50.72(b)(3)(v)(D) via an 8-hour prompt report as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. Upon further review, MPS2 determined that there was no loss of safety function. An engineering evaluation determined that even with the control room boundary door unable to be fully closed due to the latching mechanism being stuck in the extended position, control room air in-leakage would not have been sufficient to prevent the control room emergency ventilation system from performing its safety function. Therefore, this condition is not reportable and NRC Event Number EN53752 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector. Notified the R1DO (Carfang). | Time of Discovery | |
| ENS 53741 | 16 November 2018 05:16:00 | Surry | NRC Region 2 | On November 16, 2018 at 0202 EST, a potentially contaminated Dominion worker was transported offsite for medical attention. The individual was initially found unresponsive in a contaminated area. A partial survey was performed prior to the individual being transported offsite, and no contamination was found. The individual passed away in transit to the hospital. Follow-up surveys to verify no contamination are ongoing. A notification to OSHA (Occupational Safety and Health Administration) is planned. This event is being reported pursuant to 10CFR50.72(b)(2)(xi) due to notification of an offsite organization and 10CFR50.72(b)(3)(xii) due to a potentially contaminated worker transported offsite. The NRC Resident Inspector was notified.
Follow-up radiological surveys were performed and determined that there was no contamination on the worker, response personnel, or ambulance. The Occupation Safety and Health Administration was notified on 11/16/18. No media release is planned. The NRC Resident Inspector was notified. Notified the R2DO (Sandal) and via E-mail the NRR EO (Miller) and IRD MOC (Gott). | Fatality |