Semantic search
| Start date | Site | Region | Reactor type | Event description | |
|---|---|---|---|---|---|
| ENS 58029 | 6 November 2025 15:14:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via phone and email: On November 6, 2025, at 1014 (EST), it was determined that a licensed supervisory operator was in violation of the licensee's fitness for duty (FFD) policy. The test result was negative but determined to be reportable under 10 CFR 26.719(b)(2)(ii) due to violation of the licensee's FFD policy. The employee's unescorted access has been placed on hold in accordance with the licensee's FFD policy. The NRC Senior Resident Inspector has been notified. |
| ENS 58020 | 3 November 2025 17:15:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: On November 3, 2025, at 1215 EST, the 'A' reserve station service transformer (RSST) pilot wire lockout actuated while restoring the 'A' RSST to service. This resulted in the electrical isolation of the 'A' RSST and the Unit 1 'J' emergency bus. The #3 EDG automatically started and loaded onto the Unit 1 'J' emergency bus, as designed. Operations entered the appropriate abnormal procedures and ensured stable conditions. All safety systems functioned as designed and all electrical parameters remained stable. No radiological consequences resulted from this event. This event is being reported pursuant to 10CFR50.72(b)(3)(iv)(A) due to actuation of the #3 EDG. The NRC Resident Inspector was notified. |
| ENS 58010 | 27 October 2025 18:51:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 0920 EDT on 10/28/25, the supervisor of nuclear site safety contacted the area director of OSHA (Occupational Safety and Health Administration) to notify them of a work-related injury which resulted in the employee being admitted to a hospital. The individual was not contaminated and was transported offsite to Chippenham Hospital in Richmond, VA. This was a 24-hour notification in accordance with 29 CFR 1904.8. The NRC Resident Inspector has been notified. |
| ENS 57997 | 22 October 2025 01:08:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via email and phone: On October 21, 2025, at 2108 EDT, Unit 1 automatically tripped from 74 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 via the steam generator power-operated relief valves and Unit 1 is in a normal shutdown electrical lineup. Unit 2 was not affected by this event. The NRC Resident Inspector has been notified. |
| ENS 57968 | 6 October 2025 10:27:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: On October 6, 2025, at 0627 EDT, a notification to the Occupational Safety and Health Administration (OSHA) was initiated due to a Dominion employee experiencing a non-work-related medical event that resulted in the employee passing. When the issue was identified, the station first aid team responded to administer first aid. Upon arrival, the employee was nonresponsive with no pulse. The employee was pronounced deceased on site at 0627 EDT. A report to OSHA will be made in accordance with federal requirements. This event is reportable to the NRC per 10 CFR 50.72(b)(2)(xi) since another government agency will be notified of this fatality. The employee was in the plant protected area and was not contaminated. The NRC Resident Inspector has been notified. |
| ENS 57912 | 10 September 2025 02:50:00 | Millstone | NRC Region 1 | CE | The following information was provided by the licensee via phone and fax: Entry into shutdown technical specification action statement due to an identified breach in ventilation ductwork. At 2250 EDT on September 9, 2025, it was discovered that there was degraded manway sealant on the manway to fire damper HV-298A. This degraded sealant results in a direct path from the enclosure building to the atmosphere, challenging the enclosure building boundary. This condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(C). There is no impact on the health and safety of the public or plant personnel. The plant is currently in a 24-hour technical specification action statement (3.6.5.2) for Unit 2. Unit 3 is not impacted and continues to operate at 100 percent power. The Resident Inspector has been notified.
The following information was provided by the licensee via phone and fax: Millstone Unit 2 is retracting NRC Event Notification (EN) 57912, made on September 10, 2025, at 0523 EDT, regarding a condition identified at Millstone Power Station Unit 2. The condition involved degraded sealant on manways to fire dampers HV-298A/B/G, which resulted in a direct path from the enclosure building to the atmosphere, challenging the integrity of the enclosure building boundary. This condition was initially reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(C) for an event or condition that could have prevented the fulfillment of a safety function (control of release of radioactive material). A subsequent review using additional information on hatch design and actual seating surface determined that there is reasonable assurance the enclosure building boundary remained operable and retained its safety function to control the release of radioactive material and mitigate the consequences of an accident. Based on this assessment, Unit 2 exited Technical Specification action statement 3.6.5.2, and the condition is not reportable under 10 CFR 50.72(b)(3)(v)(C). Therefore, NRC EN 57912 is being retracted. The Resident Inspector has been notified. Notified R1DO (Ford). |
| ENS 57854 | 6 August 2025 22:47:00 | 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 1847 EDT on August 6, 2025, due to a spurious actuation of high consequence limiting safeguards train `B' (due to a false high containment pressure trip signal). Reactor coolant temperature is being maintained at 547 degrees Fahrenheit on the 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. Reactor protection system, emergency core cooling system, auxiliary feedwater system, emergency diesel generators, phase I and phase II containment isolation signals all actuated as designed. 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 and 10 CFR 50.72(b)(3)(iv)(A) for 8-hour notification of specified system actuation. The NRC Resident Inspector has been notified via cell phone. |
| ENS 57816 | 17 July 2025 15:00:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 1100 EDT on 07/17/2025, North Anna Power Station reported elevated levels of tritium in a ground water monitoring well to the State of Virginia as a non-voluntary reporting of tritium. An investigation is currently ongoing to identify the cause of the elevated tritium levels. The tritium levels in this location do not exceed any NRC regulations or reporting criteria. This notification is being made solely as a four-hour, non-emergency notification for a notification of the other government agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 57774 | 23 June 2025 02:04:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 2204 EDT on 6/22/2025, with unit 1 and unit 2 operating at 100 percent power, the 'A' reserve station service transformer (RSST) was lost which resulted in the loss of power to the '1J' emergency bus. As a result of the power loss, the '1J' emergency diesel generator (EDG) automatically started as designed and restored power to the '1J' emergency bus. During the event, the unit 1 'A' charging pump (1-CH-P-1A) automatically started as designed due to the loss of power event. Security footage reported a bright white flash associated with the 'A' RSST at the time of the event. The valid actuation of these ESF components due to loss of electrical power is reportable per 10 CFR 50.72(b)(3)(iv)(A). The '1J' emergency bus off-site power source was restored to service via an alternate source and the '1J' EDG was secured and returned to automatic. Restoration of offsite power to operable is complete. 1-CH-P-1A was secured and returned to automatic. Both units are currently stable, and an investigation is underway to determine the cause of the loss of the 'A' RSST." Unit 2 was unaffected. The NRC resident inspector was notified. |
| ENS 57703 | 10 May 2025 15:30:00 | Millstone | NRC Region 1 | CE Westinghouse PWR 4-Loop | The following information was provided by the licensee via phone and fax: On May 10, 2025, at approximately 1130 EDT, security discovered a full, un-opened can of beer in a rental vehicle inside the protected area. Security took possession of the item and removed it from site. The NRC Resident Inspector and Connecticut State Department of Energy and Environmental Protection were notified. |
| ENS 57694 | 7 May 2025 01:08:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following is a summary of information that was provided by the licensee via phone and fax: At 2108 EDT, on May 6, 2025, with Unit 3 in mode 5 at zero percent power, the plant received main steam line isolation, containment isolation phase 'A', and a safety injection signal which caused the emergency diesel generator to automatically start. The initiation signals were cause by inadvertent clearing of the pressurizer pressure low interlock during maintenance. There was no impact to decay heat removal, no injection into the core, and no loading of the emergency diesel generator. Operations staff responded and returned the plant to normal mode 5 operations. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
The following is a summary of information that was provided by the licensee via phone and email: Millstone Unit 3 is retracting NRC event notification (EN) 57694 regarding the inadvertent main steam line isolation, containment isolation phase 'A' and a safety injection (SI) signal which caused the emergency diesel generators to automatically start on May 6, 2025. This was reported as a valid actuation under 10 CFR 50.72(b)(3)(iv)(A). Subsequent evaluation has determined that the actuations were the result of an invalid signal caused by pinching a wire during a maintenance activity, which automatically unblocked the P-11 permissive. P-11 is a reactor protection permissive that automatically enables SI actuation when pressurizer pressure increases above 2000 psia. The permissive was unblocked as the result of the spiked pressurizer pressure indication caused by the pinched wires coincident with bistables associated with a separate pressurizer pressure channel tripped to support rescaling activities. With the plant shutdown, steam line pressures were low which met the condition to require a SI actuation with P-11 unblocked. This unblocking and resultant actuation was not a result of valid signals and was not an intentional manual actuation. The pinching of a wire causing a spike is not a valid signal and was not representative of actual plant conditions. Therefore, this condition is not reportable, and NRC EN 57694 is being retracted. The basis for this conclusion has been provided to the acting NRC Senior Resident Inspector." Notified R1DO (Warnek) |
| ENS 57793 | 7 May 2025 01:08:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following is a summary of information that was provided by the licensee via phone and fax: Millstone Power Station Unit 3 is submitting a 60-day telephonic notification in lieu of a licensee event report (LER) submittal as allowed by 10 CFR 50.73 (a)(1) for an invalid system actuation reportable under 10 CFR 50.73(a)(2)(iv)(A). On May 6, 2025, at approximately 2108 EDT, while Millstone Power Station Unit 3 was in mode 5 during a refueling outage, an invalid safety injection (SI) signal was initiated. The actuation was not the result of intentional manual actuation and not in response to actual plant conditions requiring safety system operation. This resulted in the automatic start of both emergency diesel generators (EDGs), and the complete initiation on both trains of the following: main steam line isolation, containment isolation phase 'A', and safety injection signal. No injection into the reactor coolant system occurred, and the EDGs remained unloaded. All equipment not administratively locked out responded as designed, and the plant remained stable throughout the event. Control room operators responded in accordance with appropriate operating procedures and restored the affected systems. This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B)- including safety injection signal, containment isolation signal, and start of both emergency diesel generators. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector was notified of the event. |
| ENS 57645 | 4 April 2025 04:14:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 0002 EDT on 4/4/25, Unit 2 was in mode 3 with all three reactor coolant pumps (RCPs) running in preparation for a reactor startup when an alarm for the 'B' RCP vibration alert/danger was received due to the indication of elevated vertical proximity vibrations. At 0014, the 'B' RCP vertical proximity vibration indication exceeded the pump trip setpoint and the reactor trip breakers were manually opened, followed by the 'B' RCP being manually tripped. All rods were fully inserted prior to the reactor protection system (RPS) actuation, and all required equipment responded as designed. This event is reportable in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the RPS. NRC Resident has been notified. |
| ENS 57615 | 18 March 2025 14:26:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via phone and fax: At 1026 (EDT) on March 18, 2025, it was discovered that the secondary containment boundary door was found fully open, rendering the secondary containment boundary inoperable, therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72 (b)(3)(v). The door was closed at 1029 on March 18, 2025, and the secondary containment boundary was declared operable. There is 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 2 and Unit 3 continues to operate at 100 percent power.
The following information was provided by the licensee via phone and fax: This report retracts the 8-hour notification made on March 18, 2025, for NRC Event Number EN #57615. NRC Event report number 57615 describes a condition at Millstone Power Station Unit 3 (MPS3) where a secondary containment boundary door was found fully open, rendering the secondary containment boundary inoperable. This condition was reported in accordance with 10CFR 50.72(b)(3)(v)(D) as a condition that could have prevented the fulfillment of a safety function to mitigate the consequences of an accident. Upon further review of the conditions that existed at the time, MPS3 has concluded that the door was not blocked open. The time duration from the activation of the door security alarm to the arrival of security personnel and the subsequent closure of the door was less than four minutes. The door was left unattended for less than 40 seconds, which is less than the five-minute criteria for entry and egress without special provisions. The supplementary leak collection and release system drawdown test has sufficient margin to accommodate this unattended door time. The evaluation concluded that the secondary containment boundary remained operable throughout this event and did not lose the ability to perform its safety function to control the release of radioactive material and mitigate the consequences of an accident. The basis for this conclusion will be provided to the NRC Resident Inspector. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: This event was originally reported in accordance with 10CFR 50.72(b)(3)(v)(D) and 10CFR 50.72(b)(3)(v)(C). The licensee confirmed that the retraction is applicable to both notifications. Notified R1DO (Bickett) |
| ENS 57588 | 5 March 2025 15:15:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: 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 licensee notified the NRC resident inspector. |
| ENS 57555 | 18 February 2025 07:30:00 | Millstone | NRC Region 1 | CE Westinghouse PWR 4-Loop | The following information was provided by the licensee via phone and email: At approximately 0230 EST on 2/18/2025, it was determined that the primary and backup methods of activating the site Emergency Response Organization (ERO) were not available. External network access was unavailable, to include access to the Dominion Energy Emergency Notification System (DEENS) rendering the system non-functional. Subsequently, the backup method for activating the station ERO was attempted and was unable to be verified. On 2/18/2025, at approximately 0400, an additional backup ERO activation phone number was provided and verified to be functional. At approximately 0740 on 2/18/2025, external network access was restored and DEENS was restored to functional. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(xiii). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
The following information was provided by the licensee via phone and email: It has since been determined that the (backup) phone number provided at 0400 would not have worked to activate the ERO. The NRC Resident Inspector has been notified. Notified R1DO (Deboer) |
| ENS 57553 | 18 February 2025 05:05:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At 0005 EST on February 18, 2025, the operations staff identified network issues. At 0014, Surry operations staff contacted the North Anna Power Station (NAPS) Shift Technical Advisor (STA) to inform NAPS that they had lost Dominion Energy Emergency Notification System (DEENS) capability and could not utilize the backup Emergency Response Organization (ERO) activation phone number. NAPS operations staff then confirmed that they had also lost DEENS and the ability to activate the ERO with the backup phone number. At 0400, NAPS was provided an additional phone number that can be utilized to have an Everbridge operator activate the ERO remotely. Corporate IT has been notified and is investigating. The loss of ERO activation capability is reportable per 10 CFR 50.72 (b)(3)(xiii), any event that results in a major loss of offsite communications capability. The external network access and DEENS were restored at 0720 on February 18, 2025. The NRC Resident Inspector has been notified.
The following information was provided by the licensee via phone and email: It has since been determined that the (backup) phone number provided at 0400 would not have worked to activate the ERO. However, the network issues were resolved at approximately 0700 when DEENS capability was restored. The NRC Resident Inspector has been notified. Notified R2DO (Penmetsa) |
| ENS 57552 | 18 February 2025 04:20:00 | Surry | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: At approximately 2320 EST on 02/17/2025, it was discovered that external network access was unavailable, to include access to DEENS (Dominion Energy Emergency Notification System) rendering the system non-functional. Subsequently, the backup method for activating the station ERO (Emergency Response Organization) was attempted and was unable to be verified. Therefore, neither the primary nor backup methods for activating the site ERO were available. Corporate IT has been notified and is investigating. (Control room staff) contacted the North Anna Power Station and verified similar issues with DEENS availability and backup ERO activation. On 02/18/2025, at 0403, an additional backup ERO activation phone number was provided (and documented in a standing order) in the event that the backup number listed in attachment 7 of EP-AA-CSD-201 (Notifications and Communications) is not available. This event is reportable in accordance with 10CFR50.72(b)(3)(xiii), any event that results in a major loss of offsite communications capability. The external network access and DEENS were restored on 02/18/2025 at 0725. The NRC Resident Inspector has been notified.
It has since been determined that the phone number provided at 0400 on 2/18/2025, would not have worked to activate the ERO. However, the network issues were resolved at approximately 0700 on 2/18/2025 when DEENS capability was restored. Notified R2DO (Penmetsa). |
| ENS 57383 | 15 October 2024 16:06:00 | North Anna | NRC Region 2 | Westinghouse PWR 3-Loop | The following information was provided by the licensee via phone and email: A licensed employee had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access has been terminated. The NRC Resident Inspector has been notified. |
| ENS 57422 | 10 October 2024 14:02:00 | Millstone | NRC Region 1 | Westinghouse PWR 4-Loop | The following information was provided by the licensee via phone and email: At 0902 EST, on 10/10/2024, with Millstone Unit 3 in mode 1 at 100 percent power, it was discovered that the secondary containment boundary was inoperable when the latch that secured a hatch that was part of the secondary containment boundary was not functional. The latch was repaired by 1115, on 10/10/2024, and the secondary containment boundary was declared operable at 1200, on 10/10/2024. The initial assessment of reportability concluded that an immediate report was not required. However, upon additional review, it has been determined that because the secondary containment boundary is a single-train system that performs a safety function, an 8-hour report was required in accordance with 10 CFR 50. 72 (b)(3)(v)(C) and (D). This report should have been made on 10/10/2024 and is late. There has been no impact to Unit 2, and Unit 3 continues to operate in mode 1 at 100 percent power. There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| ENS 57370 | 8 October 2024 21:53:00 | North Anna | NRC Region 2 | The following information was provided by the licensee via phone and email: This is a non-emergency notification submitted in accordance with 10 CFR 21.21(d)(3)(i). A written notification in accordance with 10 CFR 21.21(d)(3)(ii) will be provided within 20 days. On October 8, 2024, North Anna Power Station (NAPS) determined a manufacturing defect affecting the normal AC supply molded case switch for the Unit 1, 1-IV battery charger was reportable under Part 21. On July 29, 2024, the 1-IV battery charger was declared inoperable due to the AC input voltage reading approximately 250 VAC on the B-C phases and A-C phases. The A-B phase voltage was normal at 480 VAC. Troubleshooting determined the normal AC supply molded case switch was the cause of the degraded voltage due to a loose terminal connection screw on the 'C' phase load side of the contacts. The NRC Senior Resident Inspector has been notified. Battery Manufacturer: Ametek Solidstate Solutions Switch Manufacturer / Model: Eaton / J250K The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee plans to inspect all battery chargers on both units to verify they don't have loose terminal screws. They are unaware of this issue affecting any other site. | |
| ENS 57360 | 3 October 2024 15:00:00 | Kewaunee | NRC Region 3 | The following information was provided by the licensee via phone and email: At 1000 CDT, on October 3, 2024, Kewaunee Power Station was informed that the Wisconsin Department of Health Services (WDHS) was notified of an asbestos worker qualification issue specific to several workers at the Kewaunee Solutions Decommissioning Project. This notification was made by a subcontractor performing asbestos abatement work at the site and involves a lack of documentation of the worker qualifications. The NRC Regional Inspector has been notified. | |
| ENS 57282 | 21 August 2024 16:00:00 | 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 21:08:00 | 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 10:24:00 | 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. |
| ENS 57145 | 25 May 2024 08:00:00 | 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. |
| ENS 57105 | 2 May 2024 19:05:00 | 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 12:42:00 | 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. |
| ENS 56964 | 13 February 2024 22:08:00 | 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 15:54:00 | 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. |
| ENS 56743 | 18 September 2023 18:20:00 | 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 13:24:00 | 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 08:49:00 | 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). |
| ENS 56618 | 11 July 2023 19:30:00 | 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 16:32:00 | 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. |
| ENS 56787 | 18 June 2023 04:00:00 | 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 08:46:00 | 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 21:18:00 | 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 |
| ENS 56095 | 7 September 2022 13:22:00 | 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. |
| ENS 56088 | 4 September 2022 23:39:00 | 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 14:15:00 | 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 01:21:00 | 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. |
| ENS 55873 | 3 May 2022 12:19:00 | 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 13:28:00 | 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 13:09:00 | 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 16:50:00 | 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. |
| ENS 55570 | 10 November 2021 20:15:00 | 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). |
| ENS 55565 | 6 November 2021 15:00:00 | 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. |
| ENS 55459 | 13 September 2021 22:22:00 | 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. |
| ENS 55457 | 12 September 2021 21:28:00 | 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) |