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 Entered dateSiteRegionReactor typeSystemScramEvent description
ENS 5604716 August 2022 14:09:00Wolf CreekNRC Region 4Westinghouse PWR 4-LoopFeedwater
Auxiliary Feedwater
The following information was provided by the licensee via email: This 60-day telephone notification is being made under the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of the auxiliary feedwater system. At 1949 Central Daylight Time (CDT), on 7/22/22, an invalid actuation of the auxiliary feedwater system occurred due to human error. At the time of the event, Wolf Creek Generating Station was coming out of a forced outage. Plant conditions were 47 percent power with operators increasing power approximately 10 percent per hour. At this power level there was one main feedwater pump in service and Operations was performing the procedure to place the second main feedwater pump into service. A control room operator was verifying that the control oil switches were not tripped for the main feedwater pumps by verifying the bulbs for both the 'A' and 'B' trains were not lit. To verify the unlit bulbs were not burnt out, the operator was pushing the lamp test buttons. The operator successfully verified the 'A' train, but on the 'B' train the operator mistakenly pushed the bi-stable which is located directly above the bulb rather than the lamp test button. This bi-stable is the low oil pressure switch for the 'A' main feedwater pump. Because the second feedwater pump was not running yet, this caused a 'two out of two' signal for low oil pressure and caused an auxiliary feedwater system actuation. The auxiliary feedwater system responded correctly and was returned to standby condition. The Senior Resident Inspector has been notified.
ENS 5604616 August 2022 12:33:00CookNRC Region 3Westinghouse 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 terminated.
ENS 5604415 August 2022 01:18:00Palo VerdeNRC Region 4CESteam Generator
Feedwater
Emergency Diesel Generator
Auxiliary Feedwater
The following information was provided by the licensee via phone and email: At 1702 MST on August 14, 2022, a start-up transformer de-energized, resulting in a loss of power to the Unit 1 Train B 4.16 kV Class 1E Bus and the Unit 3 Train A 4.16 kV Class 1E Bus. The Unit 1 Train B Emergency Diesel Generator (EDG) and Unit 3 Train A EDG automatically started and energized their respective 4.16 kV Class 1E Buses. As a result of the loss of power on the Unit 1 Train B 4.16 kV Class 1E Bus, the B Auxiliary Feedwater Pump automatically started, as expected. The B Auxiliary Feedwater Pump was not needed for steam generator level control and no auxiliary feedwater valves repositioned. The B Auxiliary Feedwater Pump did not supply feedwater to the steam generators. 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 emergency AC electrical power systems and an auxiliary feedwater system. All systems operated as expected. Per the Emergency Plan, no classification was required due to the event. The 4.16 kV Class 1E Buses in Unit 2 were not affected by the de-energization of the start-up transformer since it was not aligned as normal power for Unit 2. Units 1, 2 and 3 remain in Mode 1 at 100% power. The cause of the start-up transformer being de-energized is under investigation. No plant transient occurred as a result of this failure. The NRC Resident Inspectors have been informed.
ENS 560283 August 2022 16:25:00FarleyNRC Region 2Westinghouse PWR 3-LoopReactor Protection System
Auxiliary Feedwater
Automatic ScramThe following information was provided by the licensee via email: At 1258 CDT on August 3, 2022, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped due to the supply breakers of the 1B startup transformer opening. The fast dead bus transfer for the reactor coolant pumps did not occur during the event. Currently the plant is in Mode 3 on natural circulation. Operations responded and stabilized the plant. Decay heat is being removed by steaming with atmospheric relief valves. Unit 2 is not affected. An automatic actuation of the 1B diesel occurred because of the power loss to the 1G 4160V bus. Additionally, the actuation of motor driven and turbine driven auxiliary feedwater pumps (AFW) also occurred. AFW auto-start is an expected response from this reactor trip. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the 1B diesel and the auxiliary feedwater system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5602330 July 2022 04:00:00DresdenNRC Region 3GE-3

The following information was provided by the licensee via email: At 2217 CDT on 7/29/22, cribhouse suction bay levels were reported less than 501.5 feet due to buildup of grass on bar racks. Ultimate Heat Sink (UHS) is INOPERABLE due to Surveillance Requirement 3.7.3.1 not met. ENTER Technical Specification (TS) 3.7.3 condition A (Required Action (RA) A.1 mode 3 in 12 hours, RA A.2 mode 4 in 36 hours). Dresden Lockmaster reports river level normal at 504.89 feet. Commenced trash rake operations to clear grass debris off of intake bar racks. At 0135 CDT on 7/30/22, cribhouse suction bay levels were reported at greater than 501.5 feet. Exit TS 3.7.3 condition A. Due to this INOPERABILITY, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(B). There was no impact on the health and safety of the public or plant personnel. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee notified the NRC Resident Inspector.

  • * * UPDATE ON 7/30/22 AT 1934 EDT FROM COLLIN GRISCHOTT TO BRIAN LIN * * *

At 1116 CDT on 7/30/22, a repeat condition occurred where cribhouse suction bay levels were reported < 501.5 feet due to buildup of grass on bar racks. Entered TS 3.7.3 condition A (RA A.1 mode 3 in 12 hours, RA A.2 mode 4 in 36 hours). Actions are in-progress to clear grass debris off the intake bar racks. Due to this INOPERABILITY, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(B). At 1745 CDT on 7/30/22, cribhouse suction bay levels were reported at >501.5 feet. Exit TS 3.7.3 condition A. The station continues to monitor for intake grass buildup and taking appropriate actions to maintain UHS operability. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee notified the NRC Resident Inspector. Notified R3DO (Peterson).

ENS 5601625 July 2022 13:30:00BrunswickNRC Region 2GE-4The following information was provided by the licensee via email: At 1058 Eastern Daylight Time (EDT) on July 25, 2022, it was determined that a non-licensed supervisor failed a test specified by the FFD testing program for the substance alcohol. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified.
ENS 5601323 July 2022 02:52:00Wolf CreekNRC Region 4Westinghouse PWR 4-LoopFeedwater
Auxiliary Feedwater

The following information was provided by the licensee via email: At 1949 CDT, while operating in Mode 1 at 46 percent power, an Auxiliary Feedwater actuation signal resulted from a human performance error while performing SYS AE-121 to place a second main feedwater pump in service. All systems responded correctly and were restored to standby condition. The Unit remained in Mode 1, at 47 percent power following the actuation. 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 Auxiliary Feedwater System. The Senior NRC Resident Inspector has been informed.

  • * * RETRACTION ON 8/16/22 AT 1406 EDT FROM JASON KNUST TO BRIAN P. SMITH * * *

Wolf Creek is retracting the original notification (EN# 56013) of a valid actuation and has recategorized this as a 60-day optional (see EN #56047). Notified R4DO (Werner)

ENS 5600518 July 2022 21:17:00Wolf CreekNRC Region 4Westinghouse PWR 4-LoopSteam Generator
Feedwater
Auxiliary Feedwater
Automatic Scram

The following information was provided by the licensee via email: While operating at 100 percent reactor power, the Control Room received indications of a feedwater transient, and indications of decreasing level on Steam Generator `B.' Reactor Trip occurred approximately 30 seconds after initial indications of transient at 1803 CDT on 7/18/22. All Safety Related Equipment responded as expected, including actuation of Auxiliary Feedwater. Control Room responded properly and progressed through Emergency Operating Procedures. The Unit is Stable in Mode 3. The NRC Senior Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The plant is in a normal post-trip electrical line-up. Wolf Creek intends to make a press release.

  • * * UPDATE FROM JOSHUA TURNER TO DONALD NORWOOD AT 1538 EDT ON 7/19/2022 * * *

The original event notification inadvertently indicated that a media / press release would be provided. However, no media / press release is planned. Notified R4DO (Gaddy).

ENS 5599715 July 2022 23:41:00BrunswickNRC Region 2GE-4High Pressure Coolant Injection
Reactor Core Isolation Cooling
Automatic Depressurization System
The following information was provided by the licensee via email: At 2020 Eastern Daylight Time (EDT) on July 15, 2022, the HPCI System was declared inoperable. Therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The Reactor Core Isolation Cooling (RCIC) System and Automatic Depressurization System (ADS) were operable during this time. HPCI availability was restored at 2023. Additional investigation is in-progress. There was no impact on the health and safety of the public or plant personnel. Unit 2 is not affected by this event. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: HPCI is considered inoperable but available at this time, resulting in a 14-day Shutdown LCO (Limiting Condition for Operation), due to the HPCI inoperability.
ENS 5599615 July 2022 17:34:00BraidwoodNRC Region 3Westinghouse PWR 4-LoopThe following information was provided by the licensee via email: At 1035 CDT on 7/15/2022, it was determined that a non-licensed supervisor tested positive in accordance with the fitness-for-duty testing program. The individual's authorization for site access has been terminated. The NRC Resident Inspector has been notified.
ENS 5599212 July 2022 17:25:00Browns FerryNRC Region 2GE-4High Pressure Coolant Injection
Reactor Core Isolation Cooling
Automatic Depressurization System
The following information was provided by the licensee via fax or email: At 0917 CDT on 7/12/2022, during the performance of U1 (Unit 1) High Pressure Coolant Injection (HPCI) rated flow test, the 1-FCV-73-19 (HPCI governor valve) failed to operate as expected. This condition results in U1 HPCI being inoperable; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). The Automatic Depressurization System (ADS) and Reactor Core Isolation Cooling (RCIC) system remain operable. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. U1 entered TS LCO 3.5.1 Condition C, 14-day Shutdown LCO (Limiting Condition for Operation), due to the HPCI inoperability.
ENS 5598912 July 2022 13:22:00SeabrookNRC Region 1Westinghouse PWR 4-LoopThe following information was provided by the licensee via fax or email: At 1051 EDT on July 12, 2022, Seabrook Station received report of inadvertent siren activation. Local authorities have been contacted to apprise them of inadvertent activation of sirens. No press release is planned at this time. This event is being reported pursuant to 10 CFR 50.72(b)(2)(xi). 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 inadvertent activation involved one group of nine (9) sirens in the Seabrook Beach area. The cause of the activation is under investigation.
ENS 5598812 July 2022 11:47:00DresdenNRC Region 3GE-3Reactor Protection SystemAutomatic ScramThe following information was provided by the licensee via fax or email: At 0803 EDT on 7/12/2022, with the Unit 2 in Mode 1 at 100% power, an automatic scram was received on Unit 2 following a turbine trip due to high reactor water level. The trip was uncomplicated with all systems responding normally post trip. All rods inserted to their full-in positions. 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 cause of the transient is under investigation. Operations responded using the Emergency Operating Procedure and stabilized the plant in Mode 3. Decay heat is being removed using the steam bypass valves to the condenser and the safety relief valves did not lift as a result of the trip. Reactor vessel inventory and pressure are being maintained in normal control bands. Unit 3 was not affected by this transient. There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 559817 July 2022 22:49:00CooperNRC Region 4GE-4The following information was provided by the licensee via phone and fax: On 7/7/2022, at 0740 CDT, the National Weather Service reported to Cooper Nuclear Station that the NAWAS ((National Warning System)) radio tower near Shubert, Nebraska would neither transmit nor receive. The Shubert Tower transmitter activates the EAS ((Emergency Alert System))/Tone Alert Radios used for public notification. Additional information from the National Weather Service received 7/7/2022 at 1601 (CDT) determined that the Shubert Tower transmitter is non-functional and would not likely be repaired within 24 hours. The backup notification system has been verified to be available throughout this period. This is considered to be a major loss of the Public Prompt Notification System capability. The primary notification system is not expected to be restored to service within 24 hours, and therefore this condition is reportable under 10 CFR 50.72(b)(3)(xiii), since the backup alerting methods do not meet the primary system design objective. The backup notification system is available to use for notifications if needed. The NRC Senior Resident has been informed. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The backup notification system has to be manually activated.
ENS 559764 July 2022 09:53:00Quad CitiesNRC Region 3GE-3Secondary containment
Standby Gas Treatment System
The following information was received from the licensee via email: At 0130 CDT on July 4 2022, it was discovered both trains of Standby Gas Treatment System were simultaneously inoperable due to failure to reach required flow rates. Both trains were capable of starting but failed to reach the required flow of 4000 SCFM. Secondary Containment differential pressure was not able to be maintained at greater than or equal to 0.25 inches of vacuum water gauge, causing Secondary Containment to also be inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(C) and 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.
ENS 559754 July 2022 05:57:00Quad CitiesNRC Region 3GE-3Feedwater
Reactor Protection System
Main Condenser
Manual ScramThe following information was received from the licensee via facsimile: On July 4, 2022 at 0104 CDT, with Unit 2 in Mode 1 at 100 percent power, a manual scram was inserted on U2 due to lowering reactor water level, which occurred following an unexpected closure of the 2A Feedwater Regulating Valve. Following the reactor scram, reactor water level decreased to approximately minus 16 inches, which resulted in an automatic Group II and Group III isolation (expected response). Following the scram, reactor water level rose to plus 75 inches resulting in a trip of all three Reactor Feedwater Pumps. At 0114 CDT, Reactor Water Level lowered to less than the Feedwater Pump High Level Trip setpoint and the 2C Reactor Feedwater Pump was restarted. Reactor Water Level control has been established in a normal band. The cause and details of the event are under investigation. The Unit 2 scram was not complicated. Operations responded using the Emergency Operating Procedure and stabilized the plant in mode 3. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 1 was unaffected by the event and remains 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). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee will notify the Illinois Emergency Management Agency.
ENS 5597330 June 2022 18:07:00Grand GulfNRC Region 4GE-6Feedwater
Service water
Reactor Protection System
Control Rod
Manual ScramThe following information was provided by the licensee via phone and email: At 1445 (CDT) on June 30, 2022, with Grand Gulf Nuclear Station in Mode 1 and at 100 percent power, the reactor was manually scrammed due to the loss of balance of plant (BOP) transformer 23. All control rods fully inserted into the core and all systems responded appropriately. Reactor level is being maintained with condensate and feedwater. Reactor pressure is being maintained with turbine bypass valves. The cause of the loss of BOP transformer 23 is under investigation at this time. Standby Service Water 'A' and 'B' were manually initiated to supply cooling to Control Room A/C, ESF switchgear room coolers, and plant auxiliary loads. This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) as an event or condition that resulted in actuation of the Reactor Protection System and 10 CFR 50.72(b)(3)(iv)(A) due to the actuation of Standby Service Water. The NRC Senior Resident Inspector was notified.
ENS 5597230 June 2022 14:21:00CallawayNRC Region 4Westinghouse PWR 4-LoopService waterThe 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 5596828 June 2022 18:03:00ColumbiaNRC Region 4GE-5A non-licensed supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's unescorted access has been terminated. The NRC Resident Inspector has been notified.
ENS 5596425 June 2022 01:00:00FermiNRC Region 3GE-4Reactor Protection System
Primary containment
Main Condenser
Control Rod
Main Steam
Automatic ScramThe following information was provided by the licensee via email: At 2338 EDT, on June 24, 2022, with the unit in Mode 1 at 100 percent power, the reactor automatically scrammed due to an RPS actuation following a Main Turbine Trip. The cause of the turbine trip is not known at this time. The scram was not complex, with systems responding normally post-scram. Operations responded and stabilized the plant. Reactor water level has been recovered and maintained at the normal level. Decay Heat is being removed by the Main Steam system to the main condenser using the Turbine Bypass Valves. All Control Rods inserted into the core. The transient occurred with no surveillances or activities in progress. Investigation into the cause of the Turbine Trip is in progress. 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 low reactor water level caused an isolation of Primary Containment (Groups 4/13/15) as expected. The Primary Containment Isolation Event is being reported under 10 CFR 50.72(b)(3)(iv)(A). There was no impact to the health and safety of the public or plant personnel. The NRC resident has been notified.
ENS 5596325 June 2022 00:44:00WaterfordNRC Region 4CEFeedwater
Reactor Protection System
Main Steam Isolation Valve
Control Rod
Automatic ScramThe following information was provided by the licensee via email: At 2012 CDT, Waterford 3 Steam Electric Station, Unit 3 was operating at 100 percent power when an automatic reactor trip occurred due to Main Steam Isolation Valve MS-124B going closed unexpectedly. Subsequently, both main feedwater isolation valves shut. Emergency Feedwater (EFW) was automatically actuated. Preliminary evaluation indicates that all plant systems functioned normally after the reactor trip. The unit is currently stable in Mode 3. All control rods fully inserted as expected and all other plant equipment functioned as expected. This was an uncomplicated scram. This event is being reported as a 4-hour non-emergency notification in accordance with 10 CFR 50.72(b)(2)(iv)(B) as an actuation of the reactor protection system (RPS) when the reactor is critical and as an 8-hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as valid actuation of the EFW system. The NRC Resident Inspector has been notified.
ENS 5596224 June 2022 16:28:00PerryNRC Region 3GE-6Core SprayThe following information was provided by the licensee via telephone: At 1257 EDT on June 24, 2022, it was discovered the Low Pressure Core Spray System (LPCS) was INOPERABLE. At Perry, the Low Pressure Core Spray System is considered a single train system in Modes 1, 2, and 3; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). Inoperability of the Low Pressure Core Spray system was caused by a loss of power to the LPCS Minimum Flow Valve during surveillance activities. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
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 5595321 June 2022 16:52:00Beaver ValleyNRC Region 1Westinghouse PWR 3-LoopThe following information was provided by the licensee via fax or email: At 1547 EDT on June 21, 2022, it was determined that Beaver Valley Power Station Unit No. 1 experienced a reportable chemical leak. Approximately 261 gallons of a Sodium Hypochlorite/Sodium Bromine mixture reached the ground and approximately 130.5 gallons (of the 261 gallons) progressed to the Ohio River (via storm drain). The source of the leakage has been isolated and absorbent material has been placed to contain the leakage. Following confirmation of this leakage, notifications were made to the following offsite agencies starting at 1615 EDT: National Response Center (Incident Report # 1339391) Pennsylvania Department Of Environmental Protection Beaver County Emergency Management This condition is being reported as a four-hour, non-emergency notification per 10CFR50.72(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 5594315 June 2022 09:47:00Beaver ValleyNRC Region 1Westinghouse PWR 3-LoopSteam Generator
Reactor Protection System
Auxiliary Feedwater
Main Condenser
Control Rod
Manual ScramThe following information was provided by the licensee via email: At 0724 EDT on 6/15/2022, with Unit 1 in Mode 1 at 100 percent power, the reactor was manually tripped due to lowering Steam Generator levels due to a secondary plant perturbation in the Heater Drain System. All control rods fully inserted into the core and the Auxiliary Feedwater System automatically started as designed in response to the full power reactor trip. The trip was not complex, with all systems responding normally post-trip. There was no equipment inoperable prior to the event that contributed to the reactor trip or adversely impacted plant response. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the condenser steam dump valves. Unit 2 is not affected and remains at 100 percent power and stable. 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). Additionally, 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 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 5594214 June 2022 15:57:00Prairie IslandNRC Region 3Westinghouse PWR 2-LoopThe following information was provided by the licensee via email: A licensed operator supervisor had a confirmed positive for alcohol during a random 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 NRC Senior Resident Inspector has been notified.
ENS 5593813 June 2022 18:21:00ColumbiaNRC Region 4GE-5Reactor Protection System
Primary containment
Reactor Water Cleanup

The following information was provided by the licensee via email: During thermography of a reactor protection system (RPS) distribution panel, a circuit breaker (RPS-CB-7B) was inadvertently opened. This resulted in a partial loss of power to RPS Division B, which caused containment isolations to occur in multiple systems (Reactor Water Clean Up, Equipment Drains Radioactive, Floor Drains Radioactive, Reactor Recirculation, and Traversing lncore Probe). Specifically, RWCU-V-1, FDR-V-3, EDR-V-19, RRC-V-19, and TIP-V-15 all closed. All actuations occurred as designed upon the partial loss of RPS power. This event is being reported pursuant to 10 CFR 50.72(b)(3)(iv)(A) due to an unplanned valid actuation of a system pursuant to 10 CFR 50.72(b)(3)(iv)(B)(2). Additionally, this is being reported pursuant to 10 CFR 50.72 (b)(3)(xiii) for a major loss of emergency assessment capability due to the inability to assess primary containment identified and unidentified leakage rates. Emergency assessment capability was restored at 1008 PDT upon system restoration. The NRC resident was notified by the licensee.

  • * * UPDATE FROM SIMEON MORALES TO DONALD NORWOOD AT 1547 EDT ON 6/16/2022 * * *

The following information was received via email: This event is being reported pursuant to 10 CFR 50.72 (b)(3)(xiii) only for a major loss of emergency assessment capability due to the inability to assess primary containment identified and unidentified leakage rates. The containment isolation was not due to actual plant conditions or parameters meeting design criteria for containment isolation. Therefore, this is considered an invalid actuation. Updated ENS Text: During thermography of a reactor protection system (RPS) distribution panel, a circuit breaker (RPS-CB-7B) was inadvertently opened. This resulted in a partial loss of power to RPS Division B, which caused containment isolations to occur in multiple systems (Reactor Water Clean Up, Equipment Drains Radioactive, Floor Drains Radioactive, Reactor Recirculation, and Traversing Incore Probe). Specifically, RWCU-V-1, FDR-V-3, EDR-V-19, RRC-V-19, and TIP-V-15 all closed. All actuations occurred as designed upon the partial loss of RPS power. This is being reported pursuant to 10 CFR 50.72 (b)(3)(xiii) for a major loss of emergency assessment capability due to the inability to assess primary containment identified and unidentified leakage rates. Emergency assessment capability was restored at 1008 PDT upon system restoration. The plant is stable, and all effected systems have been restored. There was no impact to the health and safety of the public or plant personnel. The NRC resident has been notified. Notified R4DO (Azua).

  • * * UPDATE FROM TRACY HOWARD TO ERNEST WEST AT 1853 EDT ON 8/10/2022 * * *

The following information was received via email: At 0923 (PDT) on June 13, 2022, a partial loss of power to the Reactor Protection System (RPS) 'B' occurred due to the inadvertent opening of circuit breaker RPS-CB-7B during thermography of RPS-PP-C72/P001. The partial loss of RPS 'B' resulted in closure of primary containment isolation valves (PCIVs) in multiple systems. No plant parameters existed which would cause the opening of RPS-CB-7B or actuation of the primary containment isolation; therefore, this is considered to be an invalid actuation of a system listed in 10 CFR 50.73(a)(iv)(B). The closure of PCIVs were expected responses to the partial loss of RPS 'B'. Circuit breaker RPS-CB-7B was closed lo restore energy lo RPS 'B' at 1008 (PDT), containment isolation valves were opened, and the affected systems were returned to normal operating conditions for the current configuration per plant procedures. As indicated in 10 CFR 50.73(a)(1), in the case of an invalid actuation reported under 10 CFR 50.73(a)(2)(iv)(A), the licensee may, at its option, provide a telephonic notification lo the NRC Operations Center within 60 days of discovery of the event instead of submitting a written Licensee Event Report. This 60-day telephone notification is being made in accordance with 10 CFR 50.73(a)(1) for invalid actuations reported under 10 CFR 50.73 (a)(2)(iv)(A). This actuation was invalid since it was caused by maintenance activities and not the result of actual plant conditions warranting containment isolation. The following additional information is provided as specified in NUREG-1022: The following inboard containment isolation valves were actuated when personnel inadvertently bumped into RPS-CB-7B during the removal of a panel � RWCU-V-1 Reactor Water Cleanup Suction Inboard Isolation Valve � EDR-V-19 Drywell Equipment Drain Inboard Isolation Valve � FDR-V-3 Drywell Floor Drain Inboard Isolation Valve � RRC-V-19 Reactor Water Sample Inboard Isolation Valve � TIP-V-15 Traversing In-Core Probe Purge Isolation Valve All actuations occurred as designed upon the partial loss of RPS power. There were no actual safety consequences associated with this event since all affected equipment responded as designed. The NRG Residents have been notified. Notified R4DO (O'Keefe).

ENS 559263 June 2022 20:32:00Palo VerdeNRC Region 4CEAuxiliary Feedwater
Spray Pond
The following information was provided by the licensee via email: The following event description is based on information currently available. If, through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10 CFR 50.73. This telephone notification is being made pursuant to the reporting requirements of 10 CFR 50.73(a)(1) and 10 CFR 50.73(a)(2)(iv)(A) to describe invalid actuations of the Palo Verde Nuclear Generating Station (PVNGS) Unit 1 B Train Auxiliary Feedwater (AF) system and Essential Spray Pond (ESP) system that occurred while in a refueling outage. On April 11, 2022, at approximately 2045 Mountain Standard Time, an automatic start of the Unit 1 B Train AF and ESP systems occurred during restoration from a surveillance test. The station was conducting a surveillance test during a Unit 1 refueling outage to verify the proper responses of the Engineered Safety Features Actuation Systems to simulated design basis events. The test portion was completed satisfactorily; however, during the restoration portion, the load sequencer inadvertently cycled between Mode 0 and Mode 1 three times in immediate succession. At the time of the system actuations, one of the actuation signals associated with this portion of the test had been reset per procedure. Another actuation signal was still in while restoration steps were ongoing, but the sequencer was not expected to cycle between Modes. The system actuations did not occur as a result of actual plant conditions or parameters and are therefore invalid. The Unit 1 B Train AF and ESP system actuations were complete and the systems started and functioned successfully. For the systems that did not actuate, the reasons are clearly understood as those systems were in an overridden condition due to test configuration. The spurious actuation was not able to be replicated and a direct cause was not identified. There were no adverse impacts to public health and safety nor to plant employees. The NRC Resident Inspectors have been informed.
ENS 559221 June 2022 13:58:00Quad CitiesNRC Region 3GE-3The following information was provided by the licensee via email followed by phone call: At approximately 1043 CDT, the Quad Cities Main Control Room was notified that the Scott County Iowa warning sirens were activated in error at 1001 CDT. The sirens were not intentionally activated to notify the public of severe weather or pending emergency. This event is reportable per 10 CFR 50.72(b)(2)(xi), News Release or Notification of Other Government Agencies. This is a 4-Hour Reporting requirement. The Quad Cities NRC Resident has been notified.
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 5591526 May 2022 10:34:00Grand GulfNRC Region 4GE-6The following information was provided by the licensee via phone and email: On May 26, 2022, at 0753 CDT, the Grand Gulf Nuclear Station was notified of a spurious actuation of a single Alert Notification System siren in Tensas Parish, Louisiana. The actuation occurred during siren testing conducted at approximately 0630 CDT - no emergency conditions are present at Grand Gulf Nuclear Station. A press release from Entergy is not planned at this time. This condition is reportable under 10 CFR 50.72(b)(2)(xi) as a notification of an offsite government agency. The NRC Senior Resident Inspector has been notified.
ENS 5591024 May 2022 06:49:00CookNRC Region 3Westinghouse PWR 4-LoopSteam Generator
Reactor Protection System
Auxiliary Feedwater
Main Turbine
Main Condenser
Control Rod
Main Steam
Manual ScramThe 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 5590923 May 2022 21:01:00SusquehannaNRC Region 1GE-4Feedwater
Control Rod
Automatic ScramThe following information was provided by the licensee via email: At 1716 hours EDT on May 23, 2022, Susquehanna Steam Electric Station Unit 1 reactor automatically scrammed. Unit 1 reactor was being operated at approximately 100 percent (Rated Thermal Power) RTP. The Control Room received indication that both divisions of (Reactor Protection System) RPS actuated from (Reactor Pressure Vessel) RPV high pressure signals and all control rods fully inserted. The Main Turbine bypass valves opened automatically to control reactor pressure. Reactor water level lowered to -42 inches causing Level 3 and Level 2 isolations. (High Pressure Coolant Injection) HPCI (Emergency Core Cooling System) ECCS actuation occurred as designed at -38 inches and injected to the Reactor Vessel. No other ECCS system actuations occurred. (Reactor Core Isolation Cooling) RCIC automatically initiated as designed at -30 inches. The Operations crew subsequently maintained reactor water level at the normal operating band using Feedwater pumps. The reactor is currently stable in Mode 3. An investigation is in progress into the cause of the Automatic SCRAM. The NRC Senior Resident Inspector was notified. A voluntary notification to (Pennsylvania Emergency Management Agency) PEMA will be made. This event requires a 4 hour ENS notification in accordance with 10 CFR 50.72(b)(2)(iv)(A) & 10 CFR 50.72(b)(2)(iv)(B) and an 8 hour ENS notification in accordance with 10 CFR 50.72(b)(3)(iv)(A).
ENS 5590823 May 2022 19:15:00LaSalleNRC Region 3GE-5The following information was provided by the licensee via fax: At 1256 CST on 05/23/2022, it was discovered both trains of Control Room Area Ventilation Air Conditioning Systems were simultaneously INOPERABLE. Due to this INOPERABILITY, the system was in a condition that could have prevented the fulfillment of a safety function; 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.
ENS 5590723 May 2022 11:23:00CooperNRC Region 4GE-4Secondary containmentThe following information was provided by the licensee via email: On May 23, 2022, at 0455 CST, Cooper Nuclear Station experienced a spike in Secondary Containment differential pressure which exceeded the Technical Specifications Surveillance Requirements 3.6.4.1.1 limit of -0.25 inches of water gauge. Secondary Containment differential pressure restored to Technical Specification limits within two minutes and further investigation is ongoing. This unplanned Secondary Containment inoperability constitutes a condition reportable under 10CFR50.72(b)(3)(v)(C) and (D). The NRC Senior Resident Inspector has been informed.
ENS 5590520 May 2022 17:39:00LaSalleNRC Region 3GE-5The following information was provided by the licensee via email: At 0905 CST on 05/20/2022, it was discovered both trains of Control Room Area Filtration and Area Ventilation Air Conditioning Systems were simultaneously INOPERABLE. Due to this INOPERABILITY, the system was in a condition that could have prevented the fulfillment of a safety function; 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.
ENS 5589916 May 2022 19:51:00Peach BottomNRC Region 1GE-4Feedwater
High Pressure Coolant Injection
Main Steam Isolation Valve
Primary containment
Main Steam Line
Control Rod
Automatic ScramThe following information was provided by the licensee via fax: Unit 2 experienced multiple electrical transients resulting in a Group I Primary Containment Isolation Signal (PCIS) isolation and subsequent unit reactor scram. Low reactor water level during the automatic scram caused PCIS Group II and III isolation signals. Following the PCIS Group I isolation, all main steam lines isolated. All control rods inserted and all systems operated as designed. The following additional information was obtained from the licensee via phone in accordance with Headquarters Operations Officers Report Guidance: Peach Bottom Unit 2 automatically scrammed from 100 percent power due to an electrical transient and subsequent PCIS Group I isolation (Main Steam Isolation Valve closure). Unit 2 lost main feedwater due to the PCIS Group I isolation, however, all other systems responded as expected following the scram. High Pressure Coolant Injection is maintaining pressure control while Condensate Pumps are maintaining inventory. The unit is currently stable and in Mode 3. Peach Bottom Unit 3's Adjustable Speed Drives were impacted by the electrical transients and the unit reduced power to 98 percent power. The NRC Resident Inspector was notified.
ENS 5589613 May 2022 17:47:00MonticelloNRC Region 3GE-3Steam Jet Air EjectorThe following information was provided by the licensee via email: On 5/13/22 at 1111 CDT the station entered LCO 3.7.4 Condition B for Control Room Envelope being inoperable. This was due to results from an inspection in the Steam Jet Air Ejector room that identified steam leakage exceeding the leakage rate assumptions made in the Alternate Source Term (AST) dose analysis calculation. Therefore, this is being reported in accordance with 10CFR50.72(b)(3)(ii)(B) for an unanalyzed condition that significantly degrades plant safety and 10CFR50.72(b)(3)(v)(D) for any event or condition that at the time of discovery could have prevented fulfillment of the safety function of structures or systems that are needed to mitigate the consequences of an accident. There is no impact to the health and safety of the public. NRC Resident has been notified.
ENS 5589411 May 2022 22:25:00FermiNRC Region 3GE-4High Pressure Coolant InjectionManual ScramThe following information was provided by the licensee via email: During performance of High Pressure Coolant Injection (HPCI) Pump and Valve Operability surveillance in accordance with procedure 24.202.01, the turbine tripped without operator action. The plant was operating in Mode 1 at 10 percent power with the HPCI turbine running in a test mode at 5100 gpm with all surveillance criteria met. The surveillance was near completion at the point where the HPCI turbine is manually tripped. Before the manual trip was performed, the HPCI turbine tripped without operator action. Prior to performance of the surveillance, HPCI was provisionally operable with only satisfactory completion of Post Maintenance Testing (PMT) surveillance remaining to declare HPCI operable. HPCI surveillance testing was performed at low reactor pressure (165 psig) in Mode 2 satisfactorily. Investigation into the cause of this trip is in progress. HPCI has been declared inoperable from the time of release of the surveillance. Reactor Coolant Isolation Cooling (RCIC) was verified to be operable prior to and after the surveillance in accordance with Technical Specifications 3.5.1 condition E.1. This report is being made pursuant to 10 CFR 50.72(b)(3)(v)(D) based on an unplanned HPCI inoperability. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
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 5589110 May 2022 23:42:00Quad CitiesNRC Region 3GE-3Core Spray

The following information was provided by the licensee via fax: At 1359 CDT on May 10, 2022, the 1B LPCI Loop Upstream Injection valve (1-1001-28B) was found to have a motor operated torque switch issue and inadequate lubrication. This issue called into question the ability of the valve to close when required. At 1746 CDT on May 10, 2022, both trains of Unit 1 LPCI were made simultaneously inoperable. TS 3.6.1.3 Condition A required de-activation of 1B LPCI Loop Downstream Injection valve (1-1001-29B) which was completed at 1746 CDT. Because of the de-activation of the 1B LPCI Loop downstream injection valve and LPCI Loop select logic, both trains of LPCI were made inoperable. Due to this inoperability, the system was in a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(V). Unit 1 HPCI and both loops of Core Spray are operable. After further engineering review, it was determined that 1B LPCI Loop Upstream injection valve condition was minor in nature and would not have affected the ability of the valve to close when required. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

  • * * UPDATE AT 12:32 EDT ON 05/11/22 FROM MARK HUMPHREY TO BRIAN P. SMITH * * *

The following information was provided by the licensee via phone call and email: The last sentence in the second paragraph, "After further engineering review, it was determined that 1B LPCI Loop Upstream injection valve condition was minor in nature and would not have affected the ability of the valve to close when required," has been deleted. The licensee is continuing to follow up on the issue and believes that sentence to be unclear and premature. Notified R3DO (Skokowski).

ENS 558887 May 2022 04:37:00OconeeNRC Region 2B&W-L-LPSteam Generator
Feedwater
The following information was provided by the licensee via fax: At 2310 EDT on May 6, 2022, with Unit 3 in Mode 3, an actuation of the Emergency Feedwater (EFW) System occurred while entering a planned refueling outage. The reason for the EFW auto-start was a loss of all Main Feedwater (MFDW) Pumps which occurred when the 3A MFDW Pump tripped on steam generator (SG) overfill protection due to high level in the 3B SG. The high level in the 3B SG occurred when a Startup Feedwater Control Valve (3FDW-44) malfunctioned, resulting in excessive feedwater flow to the 3B SG. Investigation and repairs are in progress. Units 1 and 2 were not affected. This event is being reported as an 8-hr non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as a valid actuation of the EFW system. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 558785 May 2022 04:30:00Palo VerdeNRC Region 4CESteam Generator
Feedwater
Emergency Diesel Generator
Auxiliary Feedwater
The following information was provided by the licensee via email: At 1955 on May 4, 2022, a start-up transformer de-energized, resulting in a loss of power to the Unit 2 Train A 4.16 kV Class 1E Bus and the Unit 3 Train B 4.16 kV Class 1E Bus. The Unit 2 Train A Emergency Diesel Generator (EDG) and Unit 3 Train B EDG automatically started and energized their respective 4.16 kV Class 1E Buses. As a result of the Loss of Power on the Unit 3 Train B 4.16 kV Class 1E Bus, the B Auxiliary Feedwater Pump automatically started, as expected. The B Auxiliary Feedwater Pump was not needed for steam generator level control and no auxiliary feedwater valves repositioned. The B Auxiliary Feedwater Pump did not supply feedwater to the steam generators. 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 emergency AC electrical power systems and an auxiliary feedwater system.
ENS 558753 May 2022 18:44:00VogtleNRC Region 2Westinghouse PWR 4-LoopReactor Protection System
Auxiliary Feedwater
Manual ScramThe 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 558733 May 2022 14:48:00North AnnaNRC Region 2Westinghouse PWR 3-LoopThe 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 5587129 April 2022 20:44:00FitzPatrickNRC Region 1GE-4High Pressure Coolant Injection

The following information was provided by the licensee via email: At 1251 EDT on April 29, 2022, while troubleshooting the failure of the High Pressure Coolant Injection (HPCI) Exhaust Drain Pot High Level Alarm to clear, it was discovered that the High Pressure Coolant Injection exhaust line condensate drain system was not functioning as designed to support removal of condensate from the turbine exhaust. This resulted in some water accumulation in the turbine casing. Subsequently, the High Pressure Coolant Injection System was declared inoperable. As a result, this condition is being reported under 10 CFR 50.72(b)(3)(v)(D) as a condition that could have prevented fulfillment of the safety function at the time of discovery.

  • * * RETRACTION ON 07/15/22 AT 1943 EDT FROM EVAN THOMPSON TO LLOYD DESOTELL * * *

A technical evaluation of this event was performed and concluded that the HPCI system would have been operable with this condition. If HPCI turbine actuated with the estimated amount of condensate accumulated in the casing and connecting piping, it would have performed its safety function; the HPCI Turbine Exhaust Rupture Disc would not have been challenged by calculated peak pressures; and calculated water hammer loads were within specified load capacities of the turbine flange, downstream piping, struts, snubber, and spring hanger. Based on this, the condition reported in EN 55871 is being retracted. Notified R1DO (Bickett)

ENS 5586829 April 2022 07:49:00HarrisNRC Region 2Westinghouse PWR 3-LoopReactor Protection System
Auxiliary Feedwater
Main Condenser
Main Steam
Manual ScramThe following information was provided by the licensee via email: At 0405 Eastern Daylight Time (EDT), with Unit 1 in Mode 1 at 100 percent power, the reactor was manually tripped due to degrading condenser vacuum. The trip was not complex, with all systems responding normally post-trip. The Auxiliary Feedwater System started automatically as expected. Operations responded and stabilized the plant. Decay heat is being removed by the Main Steam System to the main condenser using the turbine bypass valves. Due to the Reactor Protection System actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). This event is also being reported per 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the Auxiliary Feedwater System. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: No Tech Spec limits were exceeded. Offsite power is available. The suspected cause for the loss of condenser vacuum is when performing the scheduled monthly swap of condenser vacuum pumps, a suction valve failed to shut.
ENS 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 5585926 April 2022 13:13:00BrunswickNRC Region 2GE-4Service water
Emergency Diesel Generator
Primary Containment Isolation System
Reactor Core Isolation Cooling
Shutdown Cooling
Core Spray
Residual Heat Removal
The following information was provided by the licensee via fax or email: This 60-day telephone notification is being made in lieu of an LER submittal per 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for invalid actuations of systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 0040 Eastern Standard Time (EST) on March 7, 2022, Unit 1 received inadvertent High-Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) initiation signals. Subsequently, at approximately 0148 EST on March 7, 2022, Unit 1 received inadvertent Low-Pressure Coolant Injection (LPCI) and Core Spray initiation signals. In addition, all four Emergency Diesel Generators auto started, Group 10 (Instrument Air) Primary Containment Isolation System actuations occurred, and the Residual Heat Removal (RHR) Service Water Booster pumps tripped resulting in a brief interruption (approximately 9 minutes) to the Shutdown Cooling (SDC) heatsink. Jumpers, installed per planned refueling outage activities, prevented discharge of Emergency Core Cooling Systems into the reactor. HPCI, RCIC, and RHR Loop `A' were removed from service and under clearance. RHR SDC remained operable via RHR Loop `B' and forced circulation was maintained in the reactor. At the time of these events, Unit 1 was shutdown for refueling and the `A' and `C' reactor water level transmitters had been isolated in preparation for planned replacement. Leak-by of the instrument isolation valves occurred on both transmitters. Leak-by on the `C' instrument occurred at a faster rate with the `A' instrument providing the confirmatory signals resulting in Low Level 2 (LL2) and Low Level 3 (LL3) indication at approximately 0040 EST and 0148 EST, respectively. All actuations occurred as designed for LL2 and LL3 signals. During these events, reactor water level remained stable at the Reactor Vessel Head Flange and the `B' and `D' reactor water level transmitters remained off-scale-high, as expected under these conditions. Therefore, the actuations were not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system (i.e., there was no low reactor water level condition). Considering the above, these actuations were invalid. There was no impact on the health and safety of the public or plant personnel.