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 Entered dateSiteRegionReactor typeEvent description
ENS 5597230 June 2022 14:21:00CallawayNRC Region 4Westinghouse PWR 4-LoopThe following information was provided by the licensee via phone and email: This non-emergency notification is being made pursuant to the provisions of 10 CFR 50.73(a)(1) to report the occurrence of an invalid automatic actuation satisfying the reporting criterion of 10 CFR 50.73(a)(2)(iv)(A), specifically for the actuation of one train of the Essential Service Water (ESW) system that occurred on May 1, 2022. On May 1, 2022, with the plant shut down and the core offloaded, control room personnel were performing a fast power transfer from Engineered Safety Feature (ESF) transformer XNB02 to ESF transformer XNB01. In anticipation of this activity, the `B' load shedder and emergency load sequencer (LSELS) had been removed from service. Also, at the time, a portion of the `A' ESW train was isolated to support performance of a local leak rate test (LLRT) of a containment isolation valve in the affected portion of `A' ESW train piping. Service Water was supplying cooling water flow to `A' train loads (in lieu of ESW cooling water). When the power transfer was performed, an unexpected automatic start of the `A' ESW pump, along with some associated, automatic valve repositioning, occurred. The actuation occurred due to inadvertent satisfaction of automatic start logic for the ESW pump. The logic is intended to detect loss of ESW flow when the opposite train LSELS isolates Service Water during an undervoltage condition on a safety bus. The flow transmitter involved in the actuation is situated in a portion of the ESW piping that was isolated for the LLRT. The low-flow signal from the transmitter was consequently not reflective of low cooling water flow to plant loads in light of the fact that cooling water flow was being supplied to plant loads and the transmitter was locally isolated. In regard to the ESW train actuation, therefore, although the undervoltage signal was considered a valid signal due to the voltage drop caused by the fast transfer activity, the low-flow signal from the noted transmitter was considered to be invalid. For this invalid actuation, it was concluded that the actuation was not part of a pre-planned sequence, that the affected system was not properly removed from service during the occurrence, and that the safety function had not already been performed relative to the occurrence. (The) NRC Resident Inspector has been notified and an email of this report has been sent to hoo.hoc@nrc.gov.
ENS 5595522 June 2022 02:26:00McGuireNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: At 2240 on 06/21/2022, it was discovered that both required trains of Control Room Ventilation and Control Area Chilled Water System were simultaneously inoperable; therefore, this condition is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(v)(d). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The 'B' train was restored at 2315.
ENS 5591827 May 2022 22:53:00South TexasNRC Region 4Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: On 5/25/2022 at 1354 (CDT), during the replacement of two detectors, a halon actuation occurred which resulted in an unintentional release of approximately 384 pounds of halon gas into an enclosed room in the Unit 1 Electrical Auxiliary Building. There was no impact to plant operations or plant personnel. The room was verified by station Safety Personnel to be safe for normal access. On 5/27/2022 at 2038 (CDT), Region 12 (Houston) of the Texas Commission of Environmental Quality (TCEQ) was notified of an event which met the requirements of "Emission Event" for the TCEQ of a halon release that exceeded the reportable quantity threshold of 100 pounds in a 24 hour period. The halon discharge was contained within the site protected area. Therefore, this event is not significant with respect to the health and safety of the public. The licensee has notified the NRC Resident Inspector.
ENS 5591024 May 2022 06:49:00CookNRC Region 3Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: On May 24, 2022, at 0414 EDT, while rolling the Unit 1 main turbine during the Unit 1 Cycle 31 refueling outage, the Unit 1 main turbine experienced high vibrations and the main turbine was manually tripped with reactor power at 12 percent. Main turbine vibrations persisted and the reactor was manually tripped, Main Steam Stop Valves were closed, and main condenser vacuum was broken. This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The DC Cook Resident NRC Inspector has been notified. Unit 1 is being supplied by offsite power. All control rods fully inserted. Both Motor Driven Auxiliary Feedwater Pumps started properly. Decay heat is being removed via Steam Generator Power Operated Relief Valves. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 1 remains stable in Mode 3 while conducting the Post Trip Review. No radioactive release is in progress as a result of this event.
ENS 5589311 May 2022 18:12:00MillstoneNRC Region 1Westinghouse PWR 4-LoopThe 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 558753 May 2022 18:44:00VogtleNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: At 1541 EDT on May 3, 2022, with Unit 1 in Mode 1 at 100 power, the reactor was manually tripped due to the loss of one of the main feed pumps. The trip was not complex, with all systems responding normally post-trip. No equipment was inoperable prior to the event that contributed to the event or adversely impacted plant response to the scram. Operations responded and stabilized the plant. Decay heat is being removed by Auxiliary Feedwater through the steam dumps to the condenser. Unit 2 is not affected. An automatic actuation of the Auxiliary Feedwater System (AFW) also occurred. The AFW auto-start is an expected response from the reactor trip. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the Auxiliary Feedwater System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5586729 April 2022 07:04:00SequoyahNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax: On 4/28/2022, at 2338 EDT, Sequoyah received an unexpected alarm for seismological recording initiated. At 2341 EDT, unexpected alarm 1/2 Safe Shutdown Earthquake response spectra exceeded was received. The National Earthquake Information Center was contacted to confirm there was no seismic activity, and this was also confirmed on the U.S. Geological Survey website. The alarms were determined to be invalid, and they occurred due to a failure in the seismic monitoring system. This failure results in loss of ability to assess the Emergency Action Level for Initiating Condition HU2 `Seismic event greater than Operating Basis Earthquake (OBE) levels' per procedure EPIP-1, `Emergency Plan Classification Matrix.' If an actual seismic event had occurred, HU2 could not be assessed. However, compensatory measures have been implemented and include assessing OBE criteria based on alternative criteria contained in procedure AOP-N.05, `Earthquake,' which provides conservative guidance when seismic instruments are unavailable. This is an eight-hour, non-emergency notification for an event resulting in a major loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii). There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified." The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The faulty detector was removed from service, so the remaining detector provides conservative detection as the only source to make-up the logic for a seismological alarm.
ENS 5586629 April 2022 00:19:00SequoyahNRC Region 2Westinghouse PWR 4-Loop

The following is a summary of information provided by the licensee via telephone: On 04/28/22, at 2355 EDT, with both Sequoyah Unit 1 and 2 in Mode-1, 100 percent, a Notice of Unusual Event was declared due to receiving two seismic alarms and security feeling ground movement. Additionally, security in a tower heard an explosion. Both units remain in Mode-1, 100 percent and they are investigating the validity of the seismic alarms before proceeding with the Abnormal Operating Procedure required shutdown. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee will notify the NRC Resident Inspector. The state of Tennessee and the Tennessee Valley Authority were notified. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS NRCC THD Desk(email), and DHS Nuclear SSA (email).

  • * * UPDATE ON 04/29/2022 AT 0410 EDT FROM BRIAN KLEIN TO OSSY FONT * * *

The following is a summary of information provided by the licensee via telephone: On 4/29/22, at 0406 EDT, Sequoyah Unit 1 and Unit 2 terminated the Notice of Unusual Event. The Civil Engineers determined that the alarms were due to a failed seismic indicator channel. Through interviews, only one security officer felt ground movement for a couple of seconds and heard a faint rumbling sound. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee will notify the NRC Resident Inspector. The state of Tennessee and the Tennessee Valley Authority were notified. Notified R2DO (Miller), NRR EO (Miller), and IR MOC (Gott) via email. Additionally, notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS NRCC THD Desk(email), and DHS Nuclear SSA (email).

  • * * RETRACTION ON 05/02/2022 AT 2118 EDT FROM SCOTT SEAL TO LLOYD DESOTELL * * *

The following information was provided by the licensee via email: SQN (Sequoyah Nuclear Plant) is retracting the previous NOUE (Notice of Unusual Event) declaration made on 4/28/22 at 2355 (EDT) based on Emergency Action Level HU2 for a seismic event greater than Operating Basis Earthquake levels. Following the declaration of the NOUE, the station reviewed all available indications and determined that a seismic event had not occurred. The instrumentation failure was documented under Event Notification #55867. Notified R2DO (Miller), and IR MOC (Gott), NRR EO (Miller) via email.

ENS 5585723 April 2022 16:27:00ByronNRC Region 3Westinghouse PWR 4-Loop

The following information was provided by the licensee via email: At 0854 (CDT) on April 23, 2022, while performing volumetric inspections required by ASME Code Case N-729-6, a rejectable indication on Reactor Vessel Head Penetration 75 Core Exit Thermocouple (CETC) was identified. The indication is located inboard of the J-groove weld and is OD-initiated (outer diameter - initiated). This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The repair is scheduled during the refueling outage.

  • * * UPDATE ON 04/29/22 AT 1112 EDT FROM BRYAN LYKKEBAK TO OSSY FONT * * *

The following information was provided by the licensee via telephone and email: The rejectable indication on Reactor Vessel Head Penetration 75 Core Exit Thermocouple (CETC) initiated on the outside diameter (OD) of the nozzle in an area that was not surface stress mitigated (peened). The indication was found to be acceptable for continued operation under CFR and ASME requirements and will not be repaired during this outage. The licensee notified the NRC Resident Inspector. Notified R3DO (Ziolkowski).

ENS 5585623 April 2022 06:04:00CatawbaNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: On April 23, 2022, at 0224 (EDT) hours, with Unit 2 in Mode 1 at 100 percent power, two control rods dropped during control rod testing resulting in misalignment, which required a manual reactor trip in accordance with plant procedure. All safety systems functioned as expected. The Auxiliary Feedwater system actuated as designed to provide makeup flow to the steam generators. Operations responded and stabilized the plant. Decay heat is being removed by the steam generator power operated relief valves. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The automatic start of the Auxiliary Feedwater system is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A). The cause of the dropped rods is being investigated. Unit 1 is not affected. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified." The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Electrical power is in normal off-site arrangement. All emergency electrical supplies are available.
ENS 5584819 April 2022 18:02:00CallawayNRC Region 4Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: A contract employee supervisor had a confirmed positive for illegal drugs during a random fitness-for-duty test. The employee's access to the plant has been terminated. The licensee notified the NRC Resident Inspector.
ENS 5580428 March 2022 14:55:00SeabrookNRC Region 1Westinghouse PWR 4-LoopA non-licensed employee possessed a prohibited substance (alcohol) within the Protected Area. The employee's access to the plant has been placed on hold pending results of an investigation. The NRC Resident Inspector has been notified.
ENS 557696 March 2022 00:55:00ByronNRC Region 3Westinghouse PWR 4-LoopThe following information was provided by the licensee: At 2115 CST on March 5, 2022 Byron Station Technical Support Center (TSC) emergency ventilation system supply fan belt failed. This failure affected the ability of the TSC ventilation system to maintain adequate radiological habitability in the event of an emergency with an airborne radiological release. All other capabilities of the TSC are unaffected by this condition. If an emergency was declared requiring TSC activation during this period, the TSC would be staffed and activated using existing emergency planning procedures. If the TSC becomes uninhabitable, the Station Emergency Director would relocate the TSC staff to an alternate TSC location in accordance with applicable procedures. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the discovered condition affected the functionality of an emergency response facility. The licensee notified the NRC resident inspector.
ENS 5575825 February 2022 16:10:00McGuireNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee: On 2/25/22, at 1133 EDT, the Technical Support Center (TSC) high temperature alarm annunciated in the Control Room due to an equipment malfunction that resulted in an unplanned loss of the TSC for greater than seventy-five minutes. If an emergency had been declared requiring TSC activation during this period, the TSC would have been staffed and activated using existing emergency planning procedures. If relocation of the TSC had been necessary, the Emergency Coordinator would have relocated the TSC staff to an alternate location in accordance with applicable site procedures. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the equipment malfunction affected the functionality of an emergency response facility. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5574818 February 2022 08:35:00McGuireNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via telephone and email: On 2/18/2022, McGuire Nuclear Station Unit 2 experienced a turbine runback to 55 percent power. Based on concerns with unit stability, the reactor was manually tripped at 0459 (EST). All Auxiliary Feedwater pumps started on low steam generator level as required. The reactor trip was uncomplicated with all systems responding normally post trip. A feedwater isolation occurred as designed. Unit 1 was not affected. Due to the Reactor Protection System actuation while critical, actuation of the Turbine Driven Auxiliary Feedwater Pump and Motor Driven Auxiliary Feedwater pumps along with the Feedwater Isolation, this event is being reported as a four hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B) and an 8 hour nonemergency notification per 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: All control rods fully inserted. Decay heat is being removed via the condenser and normal feedwater. Unit 2 is in a normal shutdown electrical lineup.
ENS 5574216 February 2022 17:01:00SequoyahNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At 1128 EST on 2/16/2022, the SQN (Sequoyah Nuclear) Shift Manager was notified that TVA (Tennessee Valley Authority) attempted to notify Tennessee Emergency Management Agency (TEMA) regarding routine siren testing at 0750. TVA was unable to reach TEMA via telephone land line or the Emergency Communication and Notification System (ECNS). TEMA Watch Point staff were located at their back-up facility. TVA subsequently notified TEMA via cell phone that there were communication issues with the primary and backup notification methods. It was determined that the TEMA back-up facility was not able to receive incoming calls. At 0820, TEMA positioned personnel at their primary facility in order to respond to notifications. This restored primary and backup means of notifying the state because the primary facility was not affected by the communication issues. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) as a Major Loss of Offsite Communications Capability because it affected TVA's ability to notify the State of TN. The licensee has notified the NRC Resident Inspector.
ENS 5574116 February 2022 16:42:00Watts BarNRC Region 2Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At 1159 EST, on 2/16/2022, the Watts Bar Nuclear, Shift Manager was notified that Tennessee Valley Authority (TVA) attempted to notify Tennessee Emergency Management Agency (TEMA) regarding routine siren testing at 0750 EST. TVA was unable to reach TEMA via telephone land line or the Emergency Communication and Notification System (ECNS). TEMA Watch Point staff were located at their back-up facility. TVA subsequently notified TEMA via cell phone that there were communication issues with the primary and backup notification methods. It was determined that the TEMA back-up facility was not able to receive incoming calls. At 0820 EST, TEMA positioned personnel at their primary facility in order to respond to notifications. This restored primary and backup means of notifying the state because the primary facility was not affected by the communication issues. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) as a Major Loss of Offsite Communications Capability because it affected TVA's ability to notify the State of TN. The licensee has notified the NRC Resident Inspector.
ENS 557221 February 2022 15:20:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At approximately 1025 CST on 2/1/22, the Braidwood Station Main Control Room was notified of a public notification of multiple inadvertent siren actuation affecting Braidwood Station in Will County, Illinois while testing sirens. This event is reportable per 10 CFR 50.72(b)(2)(xi), News release or notification of other Government Agencies. Braidwood NRC Resident has been notified.
ENS 557201 February 2022 11:42:00Diablo CanyonNRC Region 4Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At 1350 PST on 01/31/2022, Pacific Gas and Electric determined that a non-licensed employee supervisor violated Diablo Canyon FFD policy and had a confirmed positive on a direct observed test. The employee's access to the plant has been terminated and permanent denial has been entered into PADS. The NRC Senior Resident Inspector has been notified.
ENS 556987 January 2022 16:29:00CallawayNRC Region 4Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: At 1223 CST on January 7, 2022, Callaway Plant was in Mode 1 at approximately 100 percent power when a turbine trip / reactor trip occurred. All safety systems responded as expected with the exception of an indication issue with the 'B' Feedwater Isolation Valve, which was confirmed closed. A valid Feedwater Isolation Signal and Auxiliary Feedwater Actuation Signal were also received as a result of the reactor trip. The plant is being maintained stable in Mode 3. All control rods fully inserted from the reactor trip signal, and decay heat is being removed via the Auxiliary Feedwater and Steam Dump Systems. The NRC Senior Resident Inspector was notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The plant is in a normal shutdown electrical lineup.
ENS 556947 January 2022 09:32:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At 0120 (CST) on 01/07/2022, a partial loss of the 25KV Power Distribution System caused a loss of both the Primary and Backup Meteorological Towers at the Comanche Peak Nuclear Power Plant. This resulted in a loss of emergency assessment capability with regard to meteorological conditions. A backup diesel generator for the primary Meteorological Tower did not start due to a dead battery. After the battery issue was resolved, the diesel generator started but it subsequently tripped due to a loose fuse. The 25 KV Plant Support Power Loop feeds certain non-safety-related equipment and does not affect plant operation. Power was restored to both Meteorological Towers at 0305 (CST) on 01/07/2022 and proper operation was verified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The NRC Resident Inspector was notified.
ENS 556926 January 2022 12:29:00South TexasNRC Region 4Westinghouse PWR 4-LoopAt 0603 CST on 1/6/2022, with Unit 2 in Mode 1 at 100 percent power, the South Texas Project (STP) south switchyard electrical bus was de-energized momentarily and re-energized approximately 40 seconds later. Emergency Diesel Generators (EDG) 22 automatically started in response to loss of offsite power on Train B Engineered Safety Feature (ESF) Bus. This event is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in the valid actuation of an emergency AC electrical power system (50.72(b)(3)(iv)(B)(8)). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Unit 2 is in a 72 hour LCO per TS 3.8.1.1.A for the loss of one offsite power supply. The plant is in a normal electrical lineup. There was no impact on Unit 1.
ENS 556916 January 2022 11:06:00CookNRC Region 3Westinghouse PWR 4-Loop

The following information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: On 01/06/22 at 1044 (EST), an Unusual Event was declared due to a Fire Detection Actuation in the Unit 1, auxiliary cable vault (EAL H.U 4.1). No fire was detected. Unit 1 and Unit 2 remain at 100 percent power. The Llcensee notified the NRC Resident Inspector, the state, and local authorities. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), and DHS Nuclear SSA (email).

  • * * UPDATE FROM DAN WALTER TO TOM KENDZIA AT 1452 (EST) ON 01/06/2022 * * *

At 1441 (EST), DC Cook Unit 1 terminated their notification of unusual event. The basis for termination was that the inspection identified no damage to cables or cable trays. The fire protection system is out of service for the auxiliary cable vault with compensatory measures in effect. The licensee has notified the state and local authorities and will notify the NRC Resident Inspector. Notified R3DO (Skokowski), IRD MOC (Grant), NRR EO (Felts), IR (Kennedy)(email), NRR (Veil)(email), R3 DRA (Shuaibi)(email), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).

ENS 5561024 November 2021 21:42:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopA violation occurred concerning Comanche's Peak's Fitness-For-Duty Program. Two empty mini-bottles of alcohol were discovered in a trash can within the protected area. The event has been documented in the corrective action program. The resident inspector has been notified.
ENS 5559018 November 2021 02:21:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 2238 Eastern Standard Time (EST), on 11/17/2021, a Watts Bar Nuclear Plant contractor was transported offsite for treatment at an offsite medical facility. The offsite medical facility notified Watts Barr Nuclear Plant at 2310 EST that the individual had been declared deceased. The fatality was not work-related and the individual was inside of the Unit 1 Radiological Controlled Area. The individual was confirmed not to be contaminated. This is a four-hour notification, non-emergency for a notification of other government agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The licensee will notify OSHA.
ENS 5555028 October 2021 14:19:00Watts BarNRC Region 2Westinghouse PWR 4-LoopAt 1340 EDT on October 28, 2021, Watts Bar Nuclear Plant (WBN) Units 1 and 2 initiated voluntary communication to the State of Tennessee and local officials as part of the Nuclear Energy Institute (NEI) Groundwater Protection Initiative (GPI), after receiving analysis results for two on-site monitoring wells that indicated tritium activity above the GPI voluntary communication threshold. The suspected source, a permitted release line, has been isolated, and additional corrective actions are in progress. This condition did 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 Other Government Agency. This event is reportable 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 5554927 October 2021 20:39:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 1429 EDT on October 27, 2021 with Unit 1 in Mode 6 at 0 percent power, the 1B Emergency Diesel Generator (EDG) Load Sequencer was actuated by a valid undervoltage condition on the 1B 4160V Essential Bus that occurred during 1B Sequencer calibration activities. Valid signals were sent to both the 1B EDG and Unit 1 Auxiliary Feedwater (CA) systems. Neither system automatically started as they were both removed from service for maintenance activities at the time. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the 1B EDG and Unit 1 CA systems. There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5553921 October 2021 19:01:00Wolf CreekNRC Region 4Westinghouse PWR 4-LoopPlant cafeteria workers discovered that four gallons of cooking wine were included in a delivery to their inventory within the plant protected area. Security took possession of the sealed unopened containers and removed the alcohol from the protected area. The NRC Senior Resident Inspector has been informed.
ENS 5553821 October 2021 18:46:00CallawayNRC Region 4Westinghouse PWR 4-LoopA non-licensed employee supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified.
ENS 5552615 October 2021 23:28:00Diablo CanyonNRC Region 4Westinghouse PWR 4-LoopOn October 15, 2021, at 1749 PDT with Diablo Canyon Power Plant Unit 2 operating at approximately 90 percent power, the reactor was manually tripped in accordance with plant procedures due to increasing water level in feedwater heater 2-5B. The reactor trip was uncomplicated and the Auxiliary Feedwater system started as expected. The plant is stable in Mode 3. This notification is being made in accordance the requirements of 10 CFR 50.72(b)(2)(iv)(B) as a manual actuation of the reactor protection system and 10 CFR 50.72(b)(3)(iv)(A) as an automatic actuation of a specified safety system. The cause of the increased feedwater level is under investigation. There was no impact to the health and safety of the public or plant personnel. The Resident Inspector has been notified.
ENS 5545813 September 2021 05:53:00McGuireNRC Region 2Westinghouse PWR 4-LoopAt 0011 EDT, with Unit 2 in Mode 5 (Cold Shutdown), actuations of the 2B Diesel Generator (DG) and the 2B Motor Driven Auxiliary Feedwater (AFW) Pump occurred during Engineered Safety Features Actuation Periodic Testing while resetting the 2B DG Load Sequencer. The 2B DG was running unloaded following test actuation, and during realignment from the test, a blackout condition was experienced when the breaker opened supplying the 4160 Volt Essential Power System 2ETB from the Standby Auxiliary Power Transformer SATB. Sequencer actuation closed the emergency breaker to 2ETB and loaded the 2B Motor Driven AFW Pump onto the bus. Steam supply valves to the Turbine Driven AFW Pump were open from the previous test configuration. This event is being reported in accordance with 10CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the 2B DG and the 2B Motor Driven AFW Pump. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5544031 August 2021 16:00:00South TexasNRC Region 4Westinghouse PWR 4-LoopOn August 4, 2021 a Licensed Reactor Operator violated the station's FFD policy. The employee's unescorted access to South Texas has been terminated. The event was determined to be reportable under 10 CFR 26.719(b)(2)(ii). The NRC Resident Inspector will be been notified.
ENS 5542120 August 2021 16:00:00SequoyahNRC Region 2Westinghouse PWR 4-Loop

At 0905 EDT, it was discovered both trains of Auxiliary Building Gas Treatment System (ABGTS) were simultaneously INOPERABLE due to the auxiliary building secondary containment enclosure (ABSCE) being inoperable; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. ABSCE and ABGTS were returned to operable.

  • * * RETRACTION ON 10/14/2021 AT 0756 EDT FROM TRACY SUDOKO TO THOMAS HERRITY * * *

This is a retraction of the 8-hour Immediate notification (EN55421) made to the NRC by Sequoyah Nuclear Plant on August 20, 2021. Sequoyah is retracting this event notification based on the following: Regulatory Guidance in NUREG-1022, Revision 3, 'Event Reporting Guidelines 10 CFR 50.72 and 50.73', Sections 2.8 'Retraction and Cancellation of Event Reporting', and 4.2.3 'ENS Notification Retraction'. On August 20, 2021 personnel found door A-118 open. This door is part of the ABSCE. During the initial investigation, it was found that other personnel had the door open using Precaution A of 0-TI-SXX-000-016.0 which allows material access through ABSCE doors if the door is closed within three minutes. It was found that A-118 door had been open for greater than three minutes. With this door open the ABSCE was beyond its capability for ABGTS fan to maintain the required pressure during an Aux. Building Isolation. Thus, the site declared the ABSCE and both Trains of ABGTS inoperable per LCO 3.7.12 Conditions A, B and E. With the ABSCE being a single train system, this caused a condition that "could have prevented the fulfillment of the safety function" which requires an Immediate Notification to the NRC within eight hours under 10 CFR 50.72 (b)(3)(v)(C) and 10 CFR 50.72 (b)(3)(v)(D). This Immediate Notification was reported on August 20, 2021 at 1600 EDT. It was later determined that at 'Time of Discovery', although Door A-118 was open, it was not obstructed, the door was open by normal means, was capable of being closed and was now attended. The time requirement per 0-TI-SXX-000-016.0 for closure of an open ABSCE door is within three minutes of notification. Although the individual found holding the door was unaware of the requirement of 0-TI-SXX-000-016.0 to close the door, communications were established and the Main Control Room (MCR), upon discovery of the 'Open Door', could have directed closure starting at the Time of Discovery if required. Since the MCR was aware the door was open, had communications established with personnel at the door, the door was capable of closure and not restricted, the three minute closure requirement of 0-TI-SXX-000-016.0 was met. Subsequently, the door was closed within approximately two minutes of notification to close. The closure of the door with these procedural measures met confirmed the integrity of the ABSCE and therefore Operability of ABGTS. Based on the above critical thinking, entry into LCO 3.7.12 Condition A, B, and E was retracted on August 22, 2021 at 2044 EDT. With the LCO conditions retracted and the above determination that at the Time of Discovery safety function was maintained, the Immediate Notification per 10 CFR 50.72 (b)(3)(v)(C) and 10 CFR 50.72 (b)(3)(v)(D) was not required. The issue of Past Operability remains for instances in time that the door did not have appropriate compensatory measures in place. Any further notification required for this event will be submitted as a Licensee Event Report. Notified R2DO (Miller)

ENS 5541618 August 2021 13:51:00Wolf CreekNRC Region 4Westinghouse PWR 4-LoopAt 1036 CDT on 8/18/2021, Wolf Creek experienced a reactor trip due to low level in B Steam Generator. Auxiliary feedwater system actuated as designed. All systems actuated as expected. Decay heat is currently being removed by the auxiliary feedwater system. The NRC Senior Resident Inspector has been informed. All control rods fully inserted, and offsite power remained available.
ENS 553985 August 2021 17:30:00South TexasNRC Region 4Westinghouse PWR 4-LoopA non-licensed supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified.
ENS 553953 August 2021 19:35:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopAt approximately 1539 CDT on 8/3/2021, the Braidwood Station Main Control Room was notified of the inadvertent actuation of 17 Full Sounding sirens affecting Braidwood Station in Will County Illinois while testing other sirens. Will County EMA inadvertently actuated the sirens on 08/03/2021 at 1440 CDT. This event is reportable per 10CFR50.72(b)(2)(xi), News release or Notification of Other Government Agencies. This is a 4 Hour Reporting requirement. The Braidwood NRC Resident has been notified. See related Event Notification #55396.
ENS 5538428 July 2021 16:30:00SeabrookNRC Region 1Westinghouse PWR 4-LoopA licensed employee had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been suspended. The NRC Resident Inspector has been notified.
ENS 5537925 July 2021 16:00:00SequoyahNRC Region 2Westinghouse PWR 4-LoopAt 1238 EDT on July 25, 2021, the Unit 2 Ice Bed became INOPERABLE due to SR (Surveillance Requirement) 3.6.12.1 exceeding its surveillance interval. LCO (Limiting Condition for Operation) 3.6.12 was declared not met as required by SR 3.0.1. SR 3.6.12.1 to verify maximum ice bed temperature is less than or equal to 27 degrees F could not be completed due to a failed temperature recorder. The results of the backup method of temperature verification were verified satisfactory at 1258 EDT and the LCO condition was then exited. The ice bed is a single train system which functions to control radiation release and mitigate the consequences of an accident by scrubbing radioactive iodine and providing a heat sink to limit containment pressure within design limits, therefore the requirements of 10 CFR 50.72 (b) (3) (v) (C) and (D) were met. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 553394 July 2021 15:59:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 0911 EDT on July 4, 2021, a failure occurred on 2 out of 3 of the required seismic monitoring instruments that feed the Operational Basis Earthquake (OBE) annunciator. The failure would prevent an OBE EXCEEDED alarm on the Seismic Monitoring Panel in the Control Room. This results in a major loss of emergency assessment capability. Corrective actions are being pursued to restore the seismic monitoring instruments. Compensatory measures are in place to assure adequate monitoring capability. This is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the unplanned failure of the required seismic instruments affects the ability to assess a seismic event greater than the OBE. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 553383 July 2021 17:44:00South TexasNRC Region 4Westinghouse PWR 4-LoopOn July 03, 2021, at approximately 1011 CDT, a Security Force Supervisor at South Texas Project Electric Generating Station (STPEGS) was informed by a security officer that they had located what appeared to be drug paraphernalia inside the Protected Area. At 1033 CDT Local Law Enforcement was contacted and responded to STPEGS. At 1130 CDT the Matagorda County Sheriff's office took the item into evidence for testing to determine if there was any presence of a controlled substance. At 1311 CDT, the Matagorda County Sheriff's office notified STP Nuclear Operating Company (STPNOC) that the item tested positive for the presence of a controlled substance. At 1330 CDT the Unit 1 Shift Manager was notified. This event is being reported in accordance with 10 CFR 26.719(b)(1) for discovery or presence of illegal drugs within the protected area. STPNOC is continuing to investigate this incident. The Resident Inspector has been notified.
ENS 5532524 June 2021 14:56:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopThis is an eight-hour, non-emergency notification for a loss of Emergency Assessment Capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the Technical Support Center (TSC) supply fan belt had failed, which affects the functionality of an emergency response facility. Corrective maintenance activities will be performed to restore functionality. The work includes replacing the failed belt and restarting the TSC supply fan. The work duration is approximately 8 hours. If an emergency is declared requiring TSC activation during this period, the TSC will be staffed and activated using existing emergency planning procedures unless the TSC becomes uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC becomes necessary, the Emergency Director will relocate the TSC staff to an alternate location in accordance with applicable site procedures. (The Emergency Response Organization team has been notified of the maintenance and the possible need to relocate during an emergency.) There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector and Illinois Emergency Management Agency have been notified.
ENS 5532223 June 2021 01:55:00CookNRC Region 3Westinghouse PWR 4-LoopOn June 22, 2021, at 2331 EDT, DC Cook Unit 2 Reactor was manually tripped due to a large steam leak in a crossover pipe of the Moisture Separator Re-heater (MSR) to the low pressure turbine. This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The DC Cook Resident NRC Inspector has been notified. Unit 2 is being supplied by offsite power. All control rods fully inserted. All Auxiliary Feedwater Pumps started properly. Decay heat is being removed via the Steam Dump System. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 2 remains stable in Mode 3 while conducting the Post Trip Review. No radioactive release is in progress as a result of this event. Unit 1 was not affected.
ENS 5532021 June 2021 03:06:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopAt 0051 CDT Braidwood Unit 1 experienced an automatic reactor trip due to a generator lockout relay trip and subsequent turbine trip and reactor trip. The cause of the generator lockout relay trip is unknown at this time and is under investigation. Numerous lightning strikes were present in the area during the time of the generator lockout relay trip. Both trains of auxiliary feedwater started automatically following the reactor trip to maintain steam generator water levels. All systems responded as expected with the exception of failure of source range nuclear instruments to automatically re-energize following the reactor trip. Both source range nuclear instruments were manually energized in accordance with station procedures. The main steam dump valves are in service to the main condenser to provide heat sink cooling. The plant is being maintained at normal operating pressure and temperature. AC power is being provided by Offsite Power with the 1B Diesel Generator in standby. 1A Diesel Generator is out of service for planned maintenance. All other safety systems are available. There is no impact to Unit 2. This report is being made per 10 CFR 50.72(b)(2)(iv)(B) for a RPS actuation, 4 hr. notification, and per 10 CFR 50.72(b)(3)(iv)(A) for an automatic actuation of the Auxiliary Feedwater system, 8 hr. notification. The NRC Resident Inspector and Illinois Emergency Management Agency have been informed.
ENS 5530512 June 2021 23:57:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt time 2227 CDT on 06/12/21, Main Steam Line 2-01 Radiation Monitor 2-RE-2325 was declared to be non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in Steam Generator 2-01 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity. Compensatory measures are in place to assure adequate monitoring capability. Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL 2-01. Corrective actions are being pursued to restore 2-RE-2325 to functional status. The NRC Resident Inspector has been notified.
ENS 5530412 June 2021 22:00:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt time 1725 CDT on 06/12/21, Main Steam Line 2-03 Radiation Monitor 2-RE-2327 was declared to be non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in Steam Generator 2-03 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity. Compensatory measures are in place to assure adequate monitoring capability. Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL 2-03. Corrective actions are being pursued to restore 2-RE-2327 to functional status. The NRC Resident Inspector has been notified.
ENS 552957 June 2021 18:31:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1527 (Central Standard Time) Unit 2 Reactor tripped caused by a turbine trip due to a fault and fire on Unit 2 Main Transformer #1. All Aux Feedwater Pumps started due to steam generator Lo-Lo levels. Unit 2 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IPO-007B. The Emergency Response Guideline Network has been exited. Decay heat is being rejected to the Main Condenser via the steam dump valves. Fire was extinguished at 1546 without offsite assistance. No major injuries reported and no personnel transported offsite for medical attention. Cause of the fault and fire are under investigation. NRC Resident Inspector has been notified. All rods inserted into the core during the trip. There were no relief valves or safety valves lifted during the transient. The plant is stable in its normal shutdown electrical lineup via the auxiliary transformer with all safety equipment available. Unit 1 was not affected by the transient.
ENS 5527525 May 2021 21:38:00CatawbaNRC Region 2Westinghouse PWR 4-LoopAt 1751 EDT on May 25, 2021, it was determined the local leak rate test (LLRT) for the 2EMF-IN containment penetration did not meet 10 CFR 50 Appendix J requirements for both the inboard and outboard containment isolation valves (2MISV5230 and 2MISV5231). The LLRT was performed during the previous refueling outage at which time primary containment was not required to be operable. The leakage assigned to the penetration also resulted in total leakage exceeding the allowed overall leakage. The valves were repaired and retested satisfactory prior to entering the mode of applicability, This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A), There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5527224 May 2021 12:01:00SequoyahNRC Region 2Westinghouse PWR 4-LoopUnit 2 is not impacted and remains stable in Mode 1 at 100 percent power. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B) and in accordance with 10 CFR 50.72 (b)(3)(iv)(A) as an event that results in a valid actuation of the AFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. No relief valves opened. All Rods fully inserted. Decay heat is being removed by Auxiliary Feedwater via the steam dumps. The plant is in a normal post-trip electrical line-up.
ENS 5525915 May 2021 00:55:00CallawayNRC Region 4Westinghouse PWR 4-LoopAt approximately 1300 CDT on 05/14/2021, a contract worker, who was using a scaffold ladder to access their work area on the iso-phase bus duct system for the main transformers at the Callaway plant, fell approximately 27 feet to the ground. An ambulance was dispatched to transport the individual to a local hospital. Union Electric (Ameren Missouri) subsequently learned that the event caused the individual to have a serious injury that required an overnight hospital stay. This event is reportable to OSHA per 29 CFR 1904.39(a)(2) by the contract worker's employer and is reportable to the Missouri Public Service Commission in accordance with Missouri regulation 20 CSR 4240-3.190(3)(A). This notification is being made to the NRC pursuant to 10 CFR 50.72(b)(2)(xi) due to other government notifications that will occur as a result of a situation related to the health and safety of onsite personnel. The NRC Senior Resident Inspector has been notified of this event. The individual was not working in a contamination area.
ENS 5525613 May 2021 20:35:00South TexasNRC Region 4Westinghouse PWR 4-LoopA non-licensed temporary supervisor had a confirmed positive during a random fitness-for-duty test. The employee's access to the plant has been terminated. The NRC Resident Inspector has been notified.