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 Entered dateSiteRegionReactor typeEvent description
ENS 5742515 November 2024 12:14:00Saint LucieNRC Region 2CEThe following information was provided by the licensee via phone and email: At 1001 EST, on November 15, 2024, with Unit 1 in mode 1 at 100 percent power, the reactor was manually tripped due to three control element assemblies fully inserting into the core. The trip was uncomplicated with all systems responding normally post trip. Operations stabilized the plant in mode 3. Decay heat is being removed by the steam bypass control system and main feedwater. Unit 2 was not affected. This event is being reported pursuant to 10 CFR 50.72 (b)(2)(iv)(B). 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 insertion of the three control rods is suspected to be caused by an electrical failure; however, the cause is still being investigated.
ENS 5737210 October 2024 08:45:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via phone and email: At 0557 EDT on 10/10/2024, with Unit 2 in mode 1 at 100 percent power, the reactor automatically tripped due to turbine generator loss of field. The trip was not complex with all systems responding normally post-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). Operations responded using EOP-0, post trip immediate actions, and stabilized the plant in mode 3. Decay heat is removed by discharging steam to the main condenser using the turbine bypass valves. 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: The exciter is suspected to being the cause and is under investigation. All control rods fully inserted.
ENS 573698 October 2024 18:12:00Arkansas NuclearNRC Region 4CEThe following information was provided by the licensee via phone and email: At 1431 CDT, on October 8, 2024, Arkansas Nuclear One, Unit 2 (ANO-2) completed the analysis related to an indication revealed on head penetration '71' during reactor vessel closure head inspections. It was determined that the indication is not acceptable under the American Society of Mechanical Engineers (ASME) code requirements. The indication displays characteristics of abnormal degradation of a barrier that requires taking corrective actions to ensure the barriers capability. No leak path signal was identified during ultrasonic testing or bare metal visual inspections. The plant was in cold shutdown at zero percent power and defueled for a refueling outage at the time of discovery. Repair actions will be completed prior to plant startup from the outage. This condition has no impact to the health and safety of the public. This report is being made in accordance with 10 CFR 50.72(b)(3)(ii)(A) for degradation of a principal safety barrier. This is the only indication that is currently present; however, if additional indications are found, they will also be repaired prior to the plant startup. The NRC Senior Resident Inspector has been notified.
ENS 5724928 July 2024 21:58:00Saint LucieNRC Region 2CEThe following information was provided by the licensee via phone and email: At 1837 EDT on 7/28/24, with Unit 1 in mode 1 at 100 percent power, the reactor automatically tripped due to inadvertent closure of a main steam isolation valve. During the trip, auxiliary feedwater actuated. All other systems responded normally post-trip. Operations stabilized the plant in mode 3. Decay heat is being removed by atmospheric dump valves and auxiliary feedwater. Unit 2 is not affected. This event is being reported pursuant to 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A). The NRC resident inspector has been notified.
ENS 5723318 July 2024 18:33:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via phone and email: At 1524 (EDT) on 07/18/2024, with Unit 2 in Mode 1 at 100 percent power, the reactor automatically tripped due to a turbine trip. The trip was not complex, with all systems responding normally post-trip. Operations responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 1 implemented AOP-7K (abnormal operating procedure), overcooling event, due to a grid transient. Operations responded and stabilized Unit 1 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). There was no impact on the health and safety of the public or plant personnel. The NRC resident inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: All rods fully inserted. There were no other specified system actuations.
ENS 5717718 June 2024 06:52:00Saint LucieNRC Region 2CE

The following information was provided by the licensee by email: On 06/18/2024 at 0317 EDT with Unit 2 at 18 percent power, the reactor was manually tripped due to elevated secondary chemistry levels (sodium and chlorides). The trip was uncomplicated with all systems responding normally post trip. Operations stabilized the plant in Mode 3. Decay heat is being removed by auxiliary feedwater and atmospheric dump valves. St. Lucie Unit 1 was unaffected and remains at 100 percent power. This event is being reported pursuant 10CFR 50.72(b)(2)(iv)(B). The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: All rods fully inserted. An investigation is underway to determine the root cause of the elevated chemistry levels.

  • * * RETRACTION ON 6/24/2024 AT 1315 FROM BOB MURRELL TO ADAM KOZIOL * * *

The following retraction was provided by the licensee via email: The purpose of this notification is to retract a previous report made on 06/18/2024 at 0652 (EDT) (EN# 57177). Notification of the event to the NRC was initially made because of inserting a manual reactor trip due to elevated secondary chemistry levels (sodium and chlorides). After the initial report, Florida Power and Light has concluded that the event did not meet the reporting requirements on 10 CFR 50.72(b)(2)(iv)(B) since it was part of a normal plant shutdown. Therefore, this event is not considered an unplanned scram and is not reportable to the NRC as a Licensee Event Report per 10 CFR 50.73. The NRC Senior Resident Inspector has been notified.

ENS 5717516 June 2024 16:41:00WaterfordNRC Region 4CEThe following information was provided by the licensee via email: On June 16, 2024, at 1233 CDT, Waterford Steam Electric Station Unit 3 was operating at 93 percent power when an automatic reactor trip occurred. Immediately following the reactor trip, emergency feedwater (EFW) actuated automatically. The unit is currently in Mode 3. All control rods fully inserted. Decay heat removal is via the main condenser. Preliminary evaluation indicates that all plant systems functioned normally after the reactor trip, except steam generator (SG) feedwater pump 'A' tripped and SG '1' main feed regulatory controller went to manual. Steam generator water levels are being controlled with the SG feedwater pump 'B'. The cause of the trip is currently being investigated. 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 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 a valid actuation of the EFW system. The NRC Resident Inspector has been notified.
ENS 571614 June 2024 17:19:00Saint LucieNRC Region 2CEThe following information was provided by the licensee via email: At 1352 EDT, on June 4, 2024 with Unit 2 at 92 percent power, the reactor was manually tripped due to a loss of condenser vacuum resulting from a circulating water pump trip. The trip was uncomplicated with all systems responding normally post trip. Operations stabilized the plant in mode 3. Decay heat is being removed by steam discharge to the main condenser using the turbine bypass valves. St. Lucie Unit 1 was not affected and remains at 100 percent power. This event is being reported pursuant to 10 CFR 50.72 (b)(2)(iv)(B). The NRC Resident Inspector has been notified.
ENS 5714525 May 2024 15:26:00MillstoneNRC Region 1CE
Westinghouse PWR 4-Loop
The following information was provided by the licensee by phone and email: A 50 ml bottle of vodka was found in the Unit 3 debris basket on the exterior of the intake structure. The bottle likely came from the ultimate heat sink (Niantic Bay) during normal backwash operations by the system that collects debris. Security has discarded the contraband. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers report guidance: The bottle was found unsealed.
ENS 5713723 May 2024 11:24:00Arkansas NuclearNRC Region 4CE
B&W-L-LP
The following information was provided by the licensee via email: During a security inspection, it was determined that some past events at Entergy sites that were not reported may have met the reporting criterion of 10 CFR 26.719(b)(4). As a result, the following events at Arkansas Nuclear One, Units 1 and 2 are now being conservatively reported: On February 2, 2023, a condition report was written to document that an individual who should have been placed in a follow-up fitness for duty (FFD) program was not tested according to this program. On September 6, 2023, a subsequent condition report was written to document that a different individual who should have been placed in a follow-up FFD program was not tested according to this program. The resident inspector has been notified.
ENS 5714023 May 2024 11:24:00WaterfordNRC Region 4CEThe following information was provided by the licensee via email: During a security inspection, it was determined that some past events at Entergy sites that were not reported may have met the reporting criterion of 10 CFR 26.719(b)(4). As a result, the following event at Waterford Steam Electric Station, Unit 3 is now being conservatively reported: On May 15, 2023, a condition report was written to document that an individual who should have been placed in a follow-up fitness for duty program was not tested according to this program. The individual was no longer badged at Waterford 3 but is currently badged at another Entergy site. The resident inspector has been notified.
ENS 5712211 May 2024 22:49:00WaterfordNRC Region 4CEThe following information was provided by the licensee via phone and email: At 1655 CDT, Waterford Steam Electric Station, Unit 3 was in Mode 3 with all control rod element assemblies (CEA) fully inserted with reactor trip circuit breakers closed and individual CEA disconnects open for plant startup. During the performance of emergency feedwater surveillance testing, reactor protection system (RPS) trip set point and emergency feedwater actuation system (EFAS) initiation set point for steam generator level low was exceeded for steam generator 1. Preliminary evaluation indicates that all plant systems functioned normally. The unit is currently stable in Mode 3. All control rods remain fully inserted. This event is being reported as a eight-hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as valid actuation of the RPS and emergency feedwater systems. The NRC Resident Inspector has been notified.
ENS 570664 April 2024 19:35:00Palo VerdeNRC Region 4CE

The following information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: On 4/4/2024 at 1618 MST, a Notification of Unusual Event, HU4.2 was declared based on an unverified fire alarm in the containment building greater than 15 minutes. Palo Verde, Unit 3 was operating in Mode 1 at 91 percent power due to end of cycle coast down to a refueling outage. There is no known plant damage at this time. Offsite assistance cannot enter the containment building, therefore, offsite assistance was not requested. The plant is stable in Mode 1. The licensee notified State and local authorities and the NRC Senior Resident Inspector. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

  • * * UPDATE ON 04/04/24 AT 2313 EDT FROM YOLANDA GOOD TO IAN HOWARD * * *

The following information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: At 2013 MST, Palo Verde Unit 3 terminated the notification of unusual event. The basis for termination was that a containment entry was performed. All levels were inspected, and no fires were found. The NRC Resident Inspector has been notified. Notified R4DO (Deese), IR-MOC (Crouch), NRR-EO (Felts), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

ENS 5704725 March 2024 00:48:00Palo VerdeNRC Region 4CEThe following information was provided by the licensee via email: At 1634 MST on March 24, 2024, an engineered safety features (ESF) service transformer deenergized resulting in a loss of power to the Unit 2 Train B 4.16 kV Class 1E Bus. The Unit 2 Train B emergency diesel generator (EDG) automatically started and energized the Unit 2 Train B 4.16 kV Class 1E Bus. As a result of the loss of power on the Unit 2 Train B 4.16 kV Class 1E Bus and subsequent load sequencing after the Unit 2 Train B EDG started, the Unit 2 Train B auxiliary feedwater (AFW) pump automatically started as designed. The Train B AFW pump was not needed for steam generator level control and no auxiliary feedwater valves repositioned. The Train B AFW Pump did not supply feedwater to the steam generators. All systems operated as designed. Per the emergency plan, no classification was required due to the event. Units 1, 2, and 3 remain in Mode 1 at 100 percent power. The 4.16 kV Class 1E Buses in Units 1 and 3 were not affected by the deenergization of the ESF service transformer. The cause of the ESF service transformer being deenergized is under investigation. 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 auxiliary feedwater system. The NRC Resident Inspectors have been informed.
ENS 5704222 March 2024 01:17:00WaterfordNRC Region 4CE

The following information was provided by the licensee: A Notification of Unusual Event, HU4.4 (see note below) was declared based a fire in the protected area requiring off site assistance to extinguish. The fire was in the main transformer yard. The fire was detected at 2328 CDT on March 21, 2024, and the fire was declared out at 0009 CDT on at March 22, 2024. An automatic reactor trip was initiated due to a loss of offsite power to the "B" train and a failure to automatically transfer from unit auxiliary transformer "B" to startup transformer "B. The licensee notified State and local authorities and the NRC Resident Inspector. The NRC remained in Normal. Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email). NOTE: Due to a typographical error initiating condition HU4.1 was initially recorded for the event. The correct initiating condition is HU4.4 as now shown.

  • * * UPDATE AT 0345 EDT ON 03/22/24 FROM LARRY GONSALES TO BILL GOTT * * *

The licensee terminated the Notification of Unusual Event at 0221 CDT on 3/22/24. The licensee notified the NRC Resident Inspector. Notified R4DO (Gepford), IR-MOC (Grant), NRR-EO (Felts), DHS-SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

  • * * UPDATE AT 0420EDT ON 03/22/24 FROM JOHN LEWIS TO BILL GOTT * * *

RPS ACTUATION The following information was provided by the licensee via email: On March 21, 2024, at 2328 CDT, Waterford 3 Steam Electric Station, Unit 3 was operating at 98 percent power when an automatic reactor trip was initiated due to a loss of offsite power to the B train and a failure to automatically transfer from unit auxiliary transformer B to startup transformer B. Emergency feedwater actuation signal 2 (EFAS), safety injection actuation signal (ECCS), containment isolation actuation signal and emergency diesel generators automatically actuated. The unit is currently stable in Mode 3. All control rods fully inserted and all other plant equipment functioned as expected. Forced circulation remains with one reactor coolant pump per loop running. Decay heat removal is via the main condenser. A train safety bus is being supplied by off-site power, and B train safety bus is being supplied by emergency diesel generator B. Following the loss of offsite power to the B train, it was reported that main transformer B and startup transformer B were both on fire. The Emergency Director declared an Unusual Event at time 2337 CDT. The fire was reported extinguished at 0009 CDT on March 22, 2024, and the Unusual Event was terminated at 0221 CDT on March 22, 2024. Offsite assistance was requested. The local fire department responded to the site but the fire was extinguished by the on-shift fire brigade. NRC Region IV management was contacted regarding the emergency plan entry at 0030 CDT on March 22, 2024. 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, ECCS, Containment Isolation and Emergency Diesel Generators. The NRC Resident Inspector has been notified. Notified R4DO (Gepford)

  • * * RETRACTION OF NOTICE OF UNUSUAL EVENT FROM ON 03/26/24 AT 1721 FROM L. BROWN TO K. COTTON * * *

The initial notification in event notice #57042 by Waterford Steam Electric Station, Unit 3, reported a Notice Of Unusual Event (NOUE) emergency declaration due to a fire in the protected area requiring off site support to extinguish. The basis for retraction of the initial emergency notification is that this event did not meet the definition of a fire in the protected area that requires off site support to extinguish. Guidance provided in Nuclear Energy Institute (NEI) 99-01, Rev. 6 and implemented in Waterfords Emergency Plan procedure, initiating Condition HU4.4 states, The dispatch of an offsite firefighting agency to the site requires an emergency declaration only if it is needed to actively support firefighting efforts because the fire is beyond the capability of the Fire Brigade to extinguish. (NOTE: The Initial Notification Form sent from the Control Room at 2341 CDT on March 21, 2024, requested by and provided to the NRC Headquarter Operations Center via e-mail at 0302 CDT on March 22, 2024, stated that the Emergency Classification had been made on Initiating Condition HU4.4 rather than HU4.1)" When the event occurred on March 21, 2024, the Emergency Director declared an Unusual Event at 2337 CDT and requested offsite support based on the information available at that time including the initial assessment by the fire brigade leader and expected need for offsite support to extinguish the fire. As reported in the 0420 EDT update on March 22, 2024, the fire was reported extinguished at 0009 CDT on March 22, 2024, by the Waterford Fire Brigade without the need of offsite support." Notified R4DO (Kellar).

  • * * UPDATE AT 1209 EDT ON 03/27/24 FROM JOHN LEWIS TO KAREN COTTON * * *

The initial notification in EN 57042 by Waterford Steam Electric Station, Unit 3, reported an emergency declaration of an Unusual Event due to a fire in the protected area requiring off site support to extinguish. The basis for the update to the initial notification is that this event did not meet the definition of a Fire in the Protected Area that requires offsite support to extinguish. As provided in NEI 99-01, Rev. 6 and implemented in Waterfords emergency plan procedure, initiating condition HU4.4 states, The dispatch of an offsite firefighting agency to the site requires an emergency declaration only if it is needed to actively support firefighting efforts because the fire is beyond the capability of the Fire Brigade to extinguish. Additionally, EAL 4.1 for a fire not extinguished within 15 minutes of detection in any Table H-1 fire area was not applicable because the fire did not occur in a Table H-1 fire area. When the event occurred on March 21, 2024, the Emergency Director declared an Unusual Event at 2337 CDT and requested offsite support based on the information available at that time including the initial assessment by the fire brigade leader and expected need for offsite support to extinguish the fire. As reported in the 0420 EDT update on March 22, 2024, the fire was reported extinguished at 0009 CDT on March 22, 2024, by the Waterford Fire Brigade without the need of offsite support. (NOTE: The Initial Notification Form sent from the Control Room at 2341 CDT on March 21, 2024, requested by and provided to the Headquarters Operation Center via e-mail at 0302 CDT on March 22, 2024, stated that the emergency classification had been made on initiating condition HU4.4 rather than HU4.1) In accordance with NRC Approved guidance in FAQ 21-02 (ML21117A104), Waterford 3 is retracting the initial event notification made at 0117 EDT on March 22, 2024. The remaining events that were reported in EN 57042 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 (emergency feedwater) system, ECCS (emergency core cooling system), containment isolation and emergency diesel generators are still applicable and require no additional update at this time. The licensee also provided a site map. Notified R4DO (Kellar)

ENS 5703216 March 2024 18:36:00WaterfordNRC Region 4CEThe following information was provided by the licensee via phone and email: At 1449 CDT, Waterford 3 Steam Electric Station was operating at 100 percent power when a manual reactor trip was initiated due to main feed isolation valve (FW-184B) and main steam isolation valve (MS-124B) going closed unexpectedly. 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. 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 nonemergency 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. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Decay heat is being removed through the turbine bypass valves and the atmospheric dump valve on loop '2'. There is no primary to secondary system leakage. The cause of the isolations is still being investigated.
ENS 5699728 February 2024 17:46:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via phone and email: At 1350 EST on 2/28/2024, with Calvert Cliffs Unit 1 in Mode 5 at 0 percent power and Unit 2 in Mode 1 at 65 percent power, an actuation of the '1A' and '2A' emergency diesel generators' auto-start occurred due to an undervoltage condition on the number 11 and number 21 4kV buses which are fed from the number 11 13kV bus. The '1A' and '2A' emergency diesel generators automatically started as designed when the 4kV buses' undervoltage signals were received. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of the '1A' and '2A' emergency diesel generators. 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 undervoltage condition was caused by the feeder breaker to the number 11 13 kV bus opening during electrical maintenance.
ENS 5699124 February 2024 18:08:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via email: At 1546 EST, with unit 2 at 100 percent power, the reactor was manually tripped due to the '22' steam generator feed pump tripping. The trip was uncomplicated with all systems responding normally post-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). Operations responded using emergency operation procedure EOP-0, Post Trip Immediate Actions and EOP-1, Uncomplicated Reactor Trip and stabilized the plant in mode 3. Decay heat is removed by discharging steam to the main condenser using the turbine bypass valves. Unit 1 is not affected. ESFAS (engineered safety features actuation systems) actuation (auxiliary feedwater manual actuation) is reportable under 10 CFR 50.72(b)(3)(iv)(A) 8-hour report. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 569123 January 2024 15:38:00Saint LucieNRC Region 2CE

At 1257 EST on January 3, 2024, it was determined that a class 1 system barrier had a through wall flaw with leakage. The leakage renders both trains of high pressure safety injection inoperable. The unit is being cooled down to cold shutdown to comply with technical specifications. This event is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(A) and 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officer Report Guidance: At the time of the discovery, the unit was shutdown in mode 3. The unit was experiencing signs of reactor coolant system leakage and a shutdown was initiated in order to search for possible sources. The unit is currently cooling down and proceeding to mode 5, where the safety function is not required.

  • * *UPDATE AT 1257 EST ON 02/12/24 FROM B. MURRELL TO T. HERRITY***

The purpose of this notification update is to retract a portion of a previous report, made on 1/03/2024 at 1257 EST (EN 56912). Notification of the event to the NRC was initially made as a result of declaring both trains of unit 2 high pressure safety injection system inoperable due to reactor coolant barrier through wall leak on the vent line for the 2A2 safety injection tank. Subsequent to the initial report, Florida Power and Light has concluded that the through wall leak rate was insignificant, and therefore the safety injection system's safety-related function was maintained. Therefore, this portion of the event is not considered a safety system functional failure and is not reportable to the NRC pursuant 10 CFR 50.72(3)(v)(D). This update does not affect the original 10 CFR 50.72(b)(3)(ii)(A) report for the degraded condition related to the reactor coolant barrier through wall leak. The NRC Resident Inspector has been notified. Notified R2DO (Miller).

ENS 5689316 December 2023 04:04:00Saint LucieNRC Region 2CE

At 2045 EST on December 15, 2023, it was determined that the reactor coolant system barrier had a through wall flaw with leakage. The leakage is minor in nature and unquantifiable. The leakage is coming from the welded connection of a vent valve for safety injection tank 2A2 outlet valve rendering both trains of high-pressure safety injection inoperable. The unit is being cooled down to cold shutdown to comply with technical specifications. This event is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(A) and 10 CFR 50.72(b)(3)(v)(D). 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 unit was heating up after a maintenance outage. The leak was discovered during mode 3 walkdown.

  • * *UPDATE AT 1254 EST ON 02/12/24 FROM B. MURRELL TO T. HERRITY***

The purpose of this notification update is to retract a portion of a previous report, made on 12/16/2023 at 0404 EST (EN 56893). Notification of the event to the NRC was initially made as a result of declaring both trains of unit 2 high pressure safety injection system inoperable due to reactor coolant barrier through wall leak on the vent line for the 2A2 safety injection tank. Subsequent to the initial report, Florida Power and Light has concluded that the through wall leak rate was insignificant, and therefore the safety injection system's safety-related function was maintained. Therefore, this portion of the event is not considered a safety system functional failure and is not reportable to the NRC pursuant 10 CFR 50.72(3)(v)(D). This update does not affect the original 10 CFR 50.72(b)(3)(ii)(A) report for the degraded condition related to the reactor coolant barrier through wall leak. The NRC Resident Inspector has been notified. Notified R2DO (Miller).

ENS 5685616 November 2023 05:15:00Calvert CliffsNRC Region 1CE

The following information was provided by the licensee via email: At 0227 EST on 11/16/23, Calvert Cliffs Unit 2 experienced an automatic trip from the reactor protection system (RPS) based on reactor trip bus undervoltage (UV). At that time, a loss of U-4000-22 (13 kV to 4 kV transformer) caused a loss of 22, 23, and 24 4 kV busses. This resulted in a loss of both motor generator (MG) sets causing the reactor trip bus UV. The loss of 22 and 23 4 kV non-safety related busses resulted in a loss of main feedwater. Auxiliary feedwater (AFW) was manually initiated and is feeding both steam generators. The 2B diesel generator (DG) started and restored the 24 4 kV safety related bus. Heat removal is via the normal turbine bypass valves to the main condenser. RPS actuation is reportable under 10 CFR 50.72(b)(2)(iv)(B) - 4 hour report ESFAS (engineering safety features actuation system) actuation (2B DG start on UV) is reportable under 10 CFR 50.72(b)(3)(iv)(A) - 8 hour report AFW operation is reportable under 10 CFR 50.73(a)(2)(iv)(A) - 60 day report 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: All rods fully inserted. There was no impact on Unit 1 operations. Unit 2 is stable in mode 3.

  • * * UPDATE ON AT 0940 EST FROM KERRY HUMMER TO ADAM KOZIOL * * *

ESFAS actuation (AFW manual initiation) is reportable under 10CFR50.72(b)(3)(iv)(A) - 8 hour report Notified R1DO (Defrancisco).

ENS 5684911 November 2023 00:23:00WaterfordNRC Region 4CE

The following information was provided by the licensee via email: At 1545 CST on November 10, 2023, personnel at Waterford Steam Electric Station Unit 3 determined that 19 conduits in the engineered safety features actuation system (ESFAS) auxiliary relay cabinets A and B did not have the required fire seals for bay separation. This condition meets the criteria involving an unanalyzed condition that significantly affects plant safety. The plant is currently defueled. Decay heat is being removed by normal spent fuel cooling system operations. ESFAS is not required to be operable in the current plant mode. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. There was no impact to the health and safety of the public or plant personnel. The NRC Region 4 Branch Chief (Dixon) has been notified.

  • * * RETRACTION ON 1/8/2024 AT 1222 EST FROM PETER RAMON TO ERNEST WEST * * *

On November 10, 2023, Waterford Steam Electric Station Unit 3 reported in EN 56849 that 19 conduits in engineered safety features actuation system (ESFAS) auxiliary relay cabinets A and B did not have the required fire seals for bay separation. This condition met the criteria involving an unanalyzed condition that significantly affects plant safety. Waterford 3 has determined that the ESFAS auxiliary relay cabinets A and B jumper conduits do not require fire seals based on review of an engineering specification that specifies the size and length of conduits which require fire seals to be installed. None of the nineteen affected conduits meet the size and length criteria that would necessitate installation of a fire seal. Based on this, the condition described in EN 56849 is not considered to be an unanalyzed condition that significantly affects plant safety as described in 10 CFR 50.72(b)(3)(ii)(B) and therefore is not reportable. The licensee notified the NRC Resident Inspector. Notified R4DO (Gaddy)

ENS 568418 November 2023 13:27:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via phone and email: At 0645 EST, on November 8, 2023, with Unit 2 in Mode 3 at zero percent power, a manual actuation of the auxiliary feedwater system (AFW) occurred during a planned plant cooldown. The reason for the AFW manual-start was a trip of the 22 steam generator feed pump due to a high casing level. The 23 AFW motor driven pump was manually started in accordance with implementation of AOP-3G, Malfunction of Main Feedwater System to restore steam generator levels. There was no impact to Unit 1. 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 AFW 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 other systems were affected. No other compensatory or mitigation strategies implemented. Plant cooldown was the only significant evolution in progress. No impact to other technical specifications or limiting conditions for operation. All systems functioned as required. The electric plant is being supplied by offsite power with all diesel generators available. No significant increase in plant risk. There was nothing unusual or not understood.
ENS 568397 November 2023 18:42:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via email: At 1617 on 11/7/2023, Calvert Cliffs Unit 2 experienced an automatic trip from a Reactor Protection System (RPS) based on reactor trip bus under voltage (UV). At that time a loss of U-4000-22 caused a loss of 22, 23, and 24 4kV busses. This resulted in a loss of both motor generator (MG) sets causing the reactor trip bus UV condition. The loss of 22 and 23 4kV non-safety related busses resulted in a loss of main feedwater. Auxiliary feedwater (AFW) was manually initiated and is feeding both steam generators. The 2B diesel generator (DG) started and restored the 24 4kV safety related bus. Heat removal is via the normal turbine bypass valves to the main condenser. RPS actuation is reportable under 10 CFR 50.72(b)(2)(iv)(B) - 4-hour report. ESFAS actuation (2B DG start on UV) is reportable under 10CFR50.72(b)(3)(iv)(A) - 8-hour report. ESFAS actuation (AFW manual initiation) is reportable under 10CFR50.72(b)(3)(iv)(A) - 8-hour report. Site Senior NRC resident inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Unit 1 was unaffected. Estimation of duration of shutdown is 24 hours.
ENS 568345 November 2023 17:52:00WaterfordNRC Region 4CEThe following information was provided by the licensee via email: At 1033 CST on November 5, 2023, while in a refueling outage, it was determined that Waterford Steam Electric Station, Unit 3, did not meet the performance criteria for steam generator structural integrity in accordance with Technical Specification 6.5.9.b.1, Steam Generator Program, due to two tube failures in the number 1 steam generator. The condition was identified during performance of in-situ pressure testing. The affected tubes will be plugged. The plant is currently stable with all fuel in the spent fuel pool. Decay heat is being removed by normal spent fuel cooling system operation. This event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A) as a degraded condition. There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.
ENS 5678510 October 2023 00:38:00Palo VerdeNRC Region 4CEThe following information was provided by the licensee via email: On October 9, 2023, during the Palo Verde Nuclear Generating Station Unit 1 refueling outage, while performing a small nozzle inspection in support of boric acid walkdowns, boric acid leakage was found on the area of the weld of a pressurizer thermowell. At 1507 MST, non-destructive examination of the weld indicated leakage through the reactor coolant pressure boundary. The exam result constitutes welding or material defects in the primary coolant system that are unacceptable under ASME Section XI. 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 567277 September 2023 23:35:00Arkansas NuclearNRC Region 4CE
B&W-L-LP
The following information was provided by the licensee via email: On September 7 at 1230 CDT, Arkansas Nuclear One personnel identified 5 bottles of vanilla extract in kitchen areas located inside the Protected Area. A total of 5 bottles were identified. The bottles ranged in sizes of 1 to 4 ounces. Ingredients were listed as vanilla extracts in water and alcohol. The percentage by volume of alcohol varied from 13 - 41 percent. This report satisfied the reporting criteria of 10 CFR 26.719. The NRC Resident Inspector has been notified.
ENS 567226 September 2023 19:22:00WaterfordNRC Region 4CEThe following information was provided by the licensee via email: A supplemental contract supervisor had a confirmed positive for an illegal substance during a random fitness-for-duty test. The employee's access to the plant has been terminated.
ENS 5664430 July 2023 17:25:00WaterfordNRC Region 4CE

The following information was provided by the licensee via email: On July 30, 2023 at 1119 CDT, Waterford Steam Electric Station Unit 3 declared the control room envelope inoperable in accordance with technical specification (TS) 3.7.6.1 due to the control room envelope doors failing a door seal smoke test creating a breach in the control room envelope. Operations entered TS 3.7.6.1 Action b. Mitigating actions were implemented and tested satisfactorily by 1215 CDT. There was no impact on the health and safety of the public or plant personnel. This event is reportable pursuant to 10 CFR 50.72(b)(3)(v)(D), as an event or condition that could have prevented fulfillment of a safety function of structures or systems that are needed to mitigate the consequences of an accident, due to the control room envelope being inoperable. The NRC Resident Inspector has been notified.

  • * * RETRACTION ON 09/12/23 AT 1357 EDT FROM MONICA PEAK TO THOMAS HERRITY * * *

The original operability determination of inoperable was made based on a conservative evaluation that with presence of smoke in-leakage through Door 261 and 262, the CRE boundary could not perform its safety function. A more detailed engineering evaluation was subsequently performed. No maintenance or intrusive testing was performed on the doors after initial test failure. As documented in version 2 operability determination for condition report WF3-2023-14604, the CRE boundary remained intact for the condition identified and was able to fulfill its safety function. The licensee has notified the NRC Resident Inspector. Notified R4DO (Warnick).

ENS 5663725 July 2023 16:06:00MillstoneNRC Region 1CE

The following information was provided by the licensee via email: At 0924 (EDT) on July 25, 2023, it was discovered that both trains of control room air conditioning system were simultaneously inoperable due to an inoperable control room envelope boundary. The boundary was restored at 0925 (EDT) on July 25, 2023. This condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. There has been no impact to Unit 3 which remains at 100% power.

  • * * RETRACTION ON 09/26//23 AT 1305 EDT FROM PATRICK SIKORSKY TO JOHN RUSSELL * * *

The licensee determined in a subsequent engineering evaluation of the conditions that existed at the time, that the access hatch being open did not have an adverse impact upon the control room emergency ventilation system and the control room envelopes boundary's ability to perform their safety function including: Radiation dose to the occupants did not exceed the licensing basis, design basis accident calculated value. Protection of control room occupants from hazardous chemicals and smoke. Therefore, this condition is not reportable and NRC Event EN56637 is being retracted. The basis for this conclusion has been provided to the NRC Resident Inspector. Notified R1DO (Lally)

ENS 566106 July 2023 16:48:00MillstoneNRC Region 1CEThe following information was provided by the licensee via email: On July 6, 2023, at 1232 EDT, while operating in Mode 1 at 100 percent power, the supply check valve from the number 2 steam generator to the turbine driven auxiliary feedwater pump was determined during troubleshooting that it is not able to perform its isolation function. This failure would have resulted in the blowdown of both steam generators during a main steam line break in the number 2 steam generator main steam line upstream of the main steam isolation valves until the operators could isolate the faulted steam generator. Previous evaluation has determined that this condition constituted an unanalyzed condition that could impact containment pressure. There was no radioactive release to the environment. The steam line from the steam generator to the turbine driven auxiliary feedwater pump was isolated by use of a motor operated valve in the discharge line of the number 2 steam generator. There was no impact to Unit 3 which remains at 100 percent power. The NRC Senior Resident Inspector was notified. This condition is being reported pursuant to 10 CFR 50.72(b)(3)(ii)(B) as a condition that resulted in the nuclear power plant being in an unanalyzed condition that significantly degrades plant safety.
ENS 565512 June 2023 10:44:00Palo VerdeNRC Region 4CEThe 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 (Emergency Notification System) or under the reporting requirements of 10 CFR 50.73. At 0405 MDT on June 2, 2023, the Unit 2 reactor automatically tripped on low steam generator water levels due to degraded flow from the A main feedwater pump. Steam generator water levels reached the automatic Auxiliary Feedwater Actuation System (AFAS) setpoint resulting in automatic AFAS-1 and AFAS-2 actuations and subsequent start of both class auxiliary feedwater pumps. Steam Generator water levels are being restored to normal band with the class 1E powered motor driven auxiliary feedwater pump. Following the reactor trip, all control element assemblies inserted fully into the core. No emergency plan classification was required per the Emergency Plan. Safety related buses remained powered from offsite power during the event and the offsite power grid is stable. Both emergency diesel generators automatically started on the AFAS-1 and AFAS-2 actuations as designed and are currently running unloaded. This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and a specified system actuation in accordance with 10 CFR 50.72(b)(3)(iv)(A). The NRC Senior Resident Inspector has been informed. Unit 1 and 3 are in Mode 1 at 100 percent power. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Decay heat is being removed to main condenser via automatic steam bypass and B auxiliary feedwater pump.
ENS 5653924 May 2023 19:58:00Palo VerdeNRC Region 4CEThe following information was provided by the licensee via phone and email: On May 24th, 2023, at approximately 0710 MDT, a non-licensed contract supervisor had a confirmed positive for alcohol during a for-cause fitness-for-duty test. The individual's plant access has been terminated in accordance with station procedures. The NRC Resident Inspector has been notified.
ENS 565012 May 2023 22:41:00PalisadesNRC Region 3CE

The following information was provided by the licensee via email: At approximately 1500 (EDT) on 5/2/2023, it was determined that the commercial telecommunications capacity was lost to the Palisades Nuclear Plant (PNP) control room and technical support center due to an issue with the telecommunications provider. After discovery of the condition it was discovered that this loss also included the emergency notification system (ENS). Communications link via the satellite phone was tested satisfactorly. In addition, if needed, the satellite phone would be used to initiate call-out of the emergency response organization. The condition did not affect the ENS or commercial telecommunications capabilities at the offsite Emergency Operations Facility. The telecommunications provider has not provided an estimated repair time. PNP will be notifying the NRC resident inspector.

  • * * RETRACTION ON 06/22/23 AT 1358 EDT FROM J. LEWIS TO T. HERRITY * * *

The following information was provided by the licensee via email: This notification is being made to retract event EN 56501 that was reported on May 02, 2023. Based on further investigation, the Emergency Plan and Emergency Implementing Procedures provide an acceptable alternative routine communication system, which is satellite phones, for communicating with Federal, State, and local offsite agencies, that are in addition to the primary commercial telephone system. It was determined that no actual or potential loss of offsite communications capability existed per 10 CFR 50.72(b)(3)(xiii). This is consistent with NUREG 1022, Revision 3, Supplement 1, 'Event Report Guidelines 10 CFR 50.72(b)(3)(xiii),' and NEI 13-01, Revision 0, 'Reportable Action Levels for Loss of Emergency Preparedness Capabilities.' The NRC Decommissioning Inspector has been notified of the retraction. Commercial telecommunications to the plant were restored at approximately 0600 EDT on 5/3/2023. Notified R3DO (Orlikowski)

ENS 5648726 April 2023 06:23:00Palo VerdeNRC Region 4CEThe following information was provided by the licensee via email: On 4/25/2023 at approximately 2315 (MST) it was reported that there was possible sodium hypochlorite actively leaking near the 'A' essential spray pond (ESP). Upon investigation, it was determined that the 'low flow' line of sodium hypochlorite supply to the 'A' spray pond had developed a leak. Sodium hypochlorite had pooled at the leak location and subsequently run down the ESP apron, into the road, and into the storm drain located in the protected area fence. An estimate of approximately 300 gallons of spilled sodium hypochlorite was determined based on the time frame that the sodium hypochlorite was scheduled to start injecting into the 'A' spray pond and the time the leak was isolated. The leak was isolated on 4/25/2023 at approximately 2330. The leak was contained in the storm drain with the storm gates closed, therefore nothing was released offsite. The cleanup effort in progress includes diluting the sodium hypochlorite with domestic service water, collecting it into the storm drain, pumping it to a tank truck, and transporting it to the Palo Verde Water Resources Facility for neutralization. Condition Report 23-04519 was generated to document the leak. The Palo Verde Senior Environmental Scientist was notified and subsequently informed the Environmental Protection Agency (EPA) National Response Center (NRC#1365638) on 4/26/23 at 0005 in accordance with the 91DP-0EN03 Environmental Spill Response (local procedure). The NRC Senior Resident Inspector was also notified. No personnel were injured and no equipment was damaged as a result of the spill. The Palo Verde Fire Department was notified and the area was barricaded off to prevent personnel from entering the area during the cleanup effort.
ENS 5646813 April 2023 22:48:00Maine YankeeNRC Region 1CEThe following information was provided by the licensee via phone and email: At 1905 (EDT), a security force member discovered what appeared to be a sewage leak along the gravel roadway northwest of the gatehouse entrance. The affected area was approximately 12' X 15'. The water was slowly bubbling up from the ground about 20' along one of our access roads. Large absorbent spill containment barriers were placed at the scene to minimize the incident. Water usage was stopped within our facility, and sewer pumps isolated. The Maine State Department of Environmental Protection (DEP) was notified of the incident (DEP spill # 23-0004705). The area was inspected at approximately 2130 (EDT), and water discharge was no longer observed. Maine Yankee site management is currently in the process of contacting contractors to resolve the issue. The site is safe and secure. The concrete cask heat removal system is operable, and the temperature monitoring system is functional. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The licensee notified Region 1 personnel.
ENS 564599 April 2023 04:42:00Palo VerdeNRC Region 4CE

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. At 2144 MST on April 8, 2023, the Unit 1 reactor automatically tripped due to the loss of reactor coolant pumps stemming from the loss of 13.8 kV power to the pumps. Prior to the reactor trip, the main turbine tripped due to a loss of hydraulic pressure. The main generator output breakers did not automatically open on the turbine trip as expected so the control room operators opened the breakers per procedural guidance. Once the breakers were opened, the two 13.8 kV electrical distribution buses failed to complete a fast bus transfer, which resulted in the loss of power to the reactor coolant pumps, initiating the reactor trip. The control room operators manually actuated a main steam isolation signal per procedure, requiring use of the atmospheric dump valves. Following the reactor trip, all control element assemblies inserted fully into the core. No automatic specified system actuation was required or occurred. No emergency plan classification was required per the Emergency Plan. Safety related buses remained powered from offsite power during the event and the offsite power grid is stable. Unit 1 is stable and in Mode 3. Decay heat is being removed by the atmospheric dump valves and the class 1E powered motor driven auxiliary feedwater pump. The loss of hydraulic pressure, the main generator output breakers failing to automatically open and the fast bus transfer not actuating are being investigated. This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B). The NRC Senior Resident Inspector has been informed. Unit 2 is in a refueling outage in Mode 5 and Unit 3 is in Mode 1 at 100 percent power.

  • * * UPDATE ON 4/9/23 AT 0835 EDT FROM TANNER GOODMAN TO ADAM KOZIOL * * *

This update is being made to report the manual actuation of the B-train auxiliary feedwater pump and manual main steam isolation signal (MSIS) actuation affecting multiple main steam isolation valves (MSIVs) following the reactor trip. This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and a specified system actuation in accordance with 10 CFR 50.72(b)(3)(iv)(A). The NRC Senior Resident Inspector has been informed of the update. Notified R4DO (Warnick)

  • * * UPDATE ON 5/3/23 AT 1945 EDT FROM LORRAINE WEAVER TO JOHN RUSSELL * * *

This update is intended to clarify the initial description of the event that occurred on 4/8/2023. Prior to the reactor trip, the main turbine tripped due to a loss of hydraulic pressure. The main generator output breakers did not automatically open on the turbine trip. The control room operators manually opened the breakers per procedural guidance. Once the breakers were opened, the two 13.8 kV electrical distribution buses de-energized. A fast bus transfer did not occur per design, which resulted in the loss of power to the reactor coolant pumps, initiating the reactor trip. The control room operators manually actuated a main steam isolation signal per procedure, requiring use of the atmospheric dump valves. The NRC Senior Resident Inspector has been informed of the update. Notified R4DO (Gaddy)

ENS 5640310 March 2023 07:25:00WaterfordNRC Region 4CEThe following information was provided by the licensee via email: On 03/09/2023 at 2200 CST, Waterford (Unit) 3 entered OP-901-111, Reactor Coolant System Leakage, and OP-901-403, High Activity In Containment, due to elevated reactor coolant system (RCS) leakage in containment. On 03/10/2023, at 0030 Operations entered Technical Specification 3.4.5.2 action (c) due to unidentified leakage exceeding 1 gallon per minute (gpm). Technical Specification 3.4.5.2 action (c) requires reducing the leakage rate to within limits within 4 hours or be in at least hot standby within the next 6 hours and in cold shutdown within the following 30 hours. On 03/10/2023 at 0237 the plant discovered an unisolable RCS leak in the reactor coolant pump 1B cubicle and initiated action to complete a plant shutdown required by Technical Specifications. This event is being reported as a 4-hour report in accordance with 10 CFR 50.72(b)(2)(i) as the initiation of plant shutdown required by technical specifications. Reactor was tripped at 0521 CST on 3/10/2023.
ENS 563863 March 2023 09:48:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via phone and email: A non-licensed supervisor tested positive in accordance with the FFD (fitness-for-duty) testing program. The individual's authorization for site access has been terminated. The NRC Senior Resident Inspector has been notified.
ENS 563479 February 2023 15:40:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via email: This 60-day optional telephone notification is being made in lieu of an LER (Licensee Event Report) submittal as allowed by 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 an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B). At approximately 0637 EST on December 25, 2022, the 2B EDG inadvertently started and ran unloaded without a valid undervoltage or safety injection actuation signal. It was determined that this condition was caused by the failure of the emergency start button due to age-related degradation. The button is normally held depressed (closed) by the glass enclosure in standby. To start the EDG using the Emergency Start Button, the button is released (open) when the glass enclosure is broken, which sends a start signal to the EDG. During troubleshooting, the resistance across the button contacts was measured at zero volts DC, indicating the button had failed to an open state causing the EDG to start. The button fell apart when the glass enclosure was removed. The actuation was 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 emergency diesel generator. The NRC Resident Inspector has been notified.
ENS 563556 February 2023 13:26:00Calvert CliffsNRC Region 1CEThe following information was provided by Constellation via email: On 02/06/2023 at 0416 EST, the Constellation Emergency Response Organization (ERO) Notification Database System uploaded data files into the Mass Notification System (Everbridge) which is used to notify ERO personnel when activated. At 0630, the individual reviewing the uploaded files discovered that the data files did not upload properly and that Everbridge may not notify all ERO individuals within the required 10 minutes of system initiation. Constellation resolved the issue by 0752. During the time period of 0416 to 0752, control room operators would have been unaware that the ERO notification was not successful. Therefore, this issue constitutes a loss of offsite communications capability and is reportable under 10 CFR 50.72(b)(3)(xiii), 'The licensee shall notify the NRC as soon as practical and in all cases within eight hours of the occurrence of any event that results in a major loss of emergency assessment capability, offsite response capability, or offsite communications capability (e.g., significant portion of control room indication, Emergency Notification System, or offsite notification system).' This loss of offsite communications capability affected all Constellation nuclear stations. There was no impact on the health and safety of the public or plant personnel. Each affected station NRC Resident Inspectors have been or will be notified.
ENS 562149 November 2022 15:37:00WaterfordNRC Region 4CEA non-licensed 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.
ENS 562023 November 2022 14:05:00WaterfordNRC Region 4CEThe following information was provided by the licensee via email: This 60-day telephonic notification is being made in lieu of a licensee event report submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to 10 CFR 50.73(a)(2)(iv)(A) to provide information pertaining to an invalid engineered safety feature actuation signal. On September 6, 2022, at Waterford 3, while performing a plant protection system (PPS) power supply check, technicians observed an abnormally high voltage output. When the technicians opened the PPS bay cabinet door to adjust the voltage, they then observed low voltage indications. The direct cause of this issue is believed to be vibration induced relay chattering or an intermittent connection issue when opening the rear doors of PPS cabinets. This resulted in half the logic being met for the Engineered Safety Feature Actuation Signal (ESFAS) signals to fully actuate. The ESFAS signal opened the following valves: EFW-228A (EFW to SG 1 Primary Isolation), EFW-229A (EFW to SG 1 Backup Isolation), EFW-228B (EFW to SG 2 Primary Isolation) and EFW-229B (EFW to SG 2 Backup Isolation). This was a partial actuation of ESFAS. Affected plant systems functioned successfully. The inadvertent actuation was caused by a spurious signal and was not a valid signal resulting from actual parameter inputs. The 1992 Statements of Consideration define an invalid signal to include spurious signals including jarring of a cabinet door. In accordance with 10 CFR 50.73(a)(1) a telephone notification is being made in lieu of submitting a written licensee event report. The NRC Senior Resident Inspector has been notified. These events did not result in any adverse impact to the health and safety of the public.
ENS 561404 October 2022 15:54:00Arkansas NuclearNRC Region 4CE
B&W-L-LP
A non-licensed 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.
ENS 561361 October 2022 00:08:00Arkansas NuclearNRC Region 4CE
B&W-L-LP
A supplemental supervisor violated the station's FFD policy. The individuals access to the plant has been terminated. The licensee notified the NRC Senior Resident Inspector.
ENS 5613530 September 2022 17:13:00Saint LucieNRC Region 2CE

The following information was provided by the licensee via email: At 1608 (EDT) on September 30, 2022, it was discovered that both trains of the chemical volume and control system were simultaneously inoperable due to an unisolable piping flaw inside containment detected during plant pressurization in preparation for startup following a refueling outage. St. Lucie Unit 2 was not affected and remains at 100 percent power. This event is being reported pursuant to 10CFR50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified.

  • * * RETRACTION FROM RICHARD ROGERS TO DONALD NORWOOD AT 1155 EDT ON 11/11/2022 * * *

The following information was provided by the licensee via email: The purpose of this notification is to retract a previous report made on 09/30/2022 at 1713 EDT (EN 56135). Notification of the event to the NRC was initially made as a result of declaring both trains of U1 Chemical and Volume Control System inoperable due to a piping flaw detected during plant pressurization in preparation for startup following a refueling outage. Subsequent to the initial report, FPL (Florida Power and Light) has concluded that the flaw identified in line 2"-CH-109 did not exceed (with sufficient margin) the allowable axial flaw size utilizing the ASME Code Case N-869 methodology, and the Chemical and Volume Control System was operable but degraded for the period of concern. Therefore, this event is not considered a Safety System Functional Failure and is not reportable to the NRC as a Licensee Event Report (LER) per 10 CFR 50.73. The NRC Senior Resident Inspector has been notified. Notified R2DO (Miller).

ENS 5612826 September 2022 22:39:00Saint LucieNRC Region 2CE

The following information was provided by the licensee via email: At 1741 EDT on September 26, 2022, it was discovered that both trains of the chemical volume and control system were simultaneously inoperable due to an unisolable piping flaw detected during plant pressurization in preparation for startup following refueling outage. St. Lucie Unit 2 was not affected and remains at 100 percent power. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified.

  • * * RETRACTION FROM RICHARD ROGERS TO DONALD NORWOOD AT 1155 EST ON 11/11/2022 * * *

The following information was provided by the licensee via email: The purpose of this notification is to retract a previous report made on 09/26/2022 at 2239 EDT (EN 56128). Notification of the event to the NRC was initially made as a result of declaring both trains of U1 Chemical and Volume Control System inoperable due to a piping flaw detected during plant pressurization in preparation for startup following a refueling outage. Subsequent to the initial report, FPL (Florida Power and Light) has concluded that the flaw identified in line 2"-CH(1)104 did not exceed (with sufficient margin) the allowable axial flaw size utilizing the ASME Code Case N-869 methodology, and the Chemical and Volume Control System was Operable but degraded for the period of concern. Therefore, this event is not considered a Safety System Functional Failure and is not reportable to the NRC as a Licensee Event Report (LER) per 10 CFR 50.73. The NRC Senior Resident Inspector has been notified. Notified R2DO (Miller).

ENS 5612726 September 2022 21:16:00Palo VerdeNRC Region 4CEThe following information was provided by the licensee via email: On September 26, 2022, at approximately 1100 Mountain Standard Time, a Reactor Operator's test results were confirmed positive for use of a controlled substance following a random Fitness For Duty (FFD) screening test and it was determined that the individual violated the station's FFD Policy. The individual's unescorted access has been terminated in accordance with station procedures. 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 conduct an investigation of the individual's work history.
ENS 5610814 September 2022 21:43:00Calvert CliffsNRC Region 1CEThe following information was provided by the licensee via email: With Unit 2 in Mode 5 and cooling down for a scheduled maintenance outage, Operations was bypassing safety injection and safety injection bypass sensor modules per procedure. Due to a human performance issue, a safety injection actuation signal was generated. All equipment operated as expected. Operations has reset the safety injection actuation signal and restored the equipment to its required condition. Unit 1 was at 100 percent power and unaffected by this issue. The NRC Resident Inspector will be notified.
ENS 560873 September 2022 01:58:00Saint LucieNRC Region 2CEThe following information was provided by the licensee via email: On 09/02/2022 at 22:48 with Unit 1 at 40% power, the reactor was manually tripped due to a loss of the only operating main feed pump which caused lowering level in the steam generators. All systems responded as expected following the trip. Auxiliary feed actuation signal occurred due to lowering steam generator levels. The cause of the main feedwater pump trip is under investigation. St. Lucie Unit 2 was not affected and remains at 100% power. This event is being reported pursuant to 10 CFR 50.72 (b)(2)(iv)(B) for the reactor trip and 10 CFR 50.72 (b)(3)(iv)(A) for the auxiliary feed actuation. The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: Decay heat is being removed by using the atmospheric dump valves.