Event Notification Report for May 30, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/29/2025 - 05/30/2025
Power Reactor
Event Number: 57737
Facility: Browns Ferry
Region: 2 State: AL
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Diana Peck-Earley
HQ OPS Officer: Sam Colvard
Region: 2 State: AL
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Diana Peck-Earley
HQ OPS Officer: Sam Colvard
Notification Date: 05/31/2025
Notification Time: 03:13 [ET]
Event Date: 05/30/2025
Event Time: 22:47 [CDT]
Last Update Date: 05/31/2025
Notification Time: 03:13 [ET]
Event Date: 05/30/2025
Event Time: 22:47 [CDT]
Last Update Date: 05/31/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Desai, Binoy (R2DO)
Desai, Binoy (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | M/R | Y | 39 | Power Operation | 0 | Hot Shutdown |
MANUAL REACTOR TRIP
The following information was provided by the licensee via phone and email:
"At 2247 CDT on 5/30/25, with Unit 2 operating in mode 1 at 39 percent reactor power, the reactor was manually tripped due to a trip of the only operating reactor recirculation pump (2B). Approximately 44 minutes prior at 2203 CDT, the 2A reactor recirculation pump tripped.
"Operations responded and stabilized the plant. Primary containment isolation systems (PCIS) received an actuation signal for groups 2, 3, 6 and 8 on reactor water level at +2 inches. All primary containment systems that received an actuation signal performed as designed. All other systems functioned as designed. Reactor water level control is via condensate and feedwater, and reactor cooldown is in progress using turbine bypass valves to the main condenser.
"Due to the reactor protection system (RPS) 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 actuation of RPS and PCIS also requires an eight-hour non-emergency report per 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 Inspector has been notified."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The site reduced power from 100 percent following the loss of the 2A recirculation pump.
The following information was provided by the licensee via phone and email:
"At 2247 CDT on 5/30/25, with Unit 2 operating in mode 1 at 39 percent reactor power, the reactor was manually tripped due to a trip of the only operating reactor recirculation pump (2B). Approximately 44 minutes prior at 2203 CDT, the 2A reactor recirculation pump tripped.
"Operations responded and stabilized the plant. Primary containment isolation systems (PCIS) received an actuation signal for groups 2, 3, 6 and 8 on reactor water level at +2 inches. All primary containment systems that received an actuation signal performed as designed. All other systems functioned as designed. Reactor water level control is via condensate and feedwater, and reactor cooldown is in progress using turbine bypass valves to the main condenser.
"Due to the reactor protection system (RPS) 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 actuation of RPS and PCIS also requires an eight-hour non-emergency report per 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 Inspector has been notified."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The site reduced power from 100 percent following the loss of the 2A recirculation pump.
Agreement State
Event Number: 57775
Rep Org: SC Dept of Health & Env Control
Licensee: ECS Southeast, LLC
Region: 1
City: North Charleston State: SC
County:
License #: 885
Agreement: Y
Docket:
NRC Notified By: Adam Gause
HQ OPS Officer: Karen Cotton
Licensee: ECS Southeast, LLC
Region: 1
City: North Charleston State: SC
County:
License #: 885
Agreement: Y
Docket:
NRC Notified By: Adam Gause
HQ OPS Officer: Karen Cotton
Notification Date: 06/23/2025
Notification Time: 11:21 [ET]
Event Date: 05/30/2025
Event Time: 00:00 [EDT]
Last Update Date: 06/23/2025
Notification Time: 11:21 [ET]
Event Date: 05/30/2025
Event Time: 00:00 [EDT]
Last Update Date: 06/23/2025
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
Arner, Frank (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Allen, Logan (NMSS)
Arner, Frank (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Allen, Logan (NMSS)
AGREEMENT STATE REPORT - DOSE TO MEMBER OF THE PUBLIC GREATER THAN LIMITS
The following information was provided by the South Carolina Department of Environmental Services (the Department) via phone and email:
"The licensee submitted a written report on May 30, 2025, indicating that the estimated total effective dose equivalent to an adult member of the public was determined to be 129 mrem/year for calendar year 2023 and 106 mrem/year for calendar year 2024. The licensee later submitted an updated calculation on June 17, 2025, indicating that the estimated total effective dose equivalent to an adult member of the public was determined to be 154 mrem/year for calendar year 2024.
"The member of the public was an employee of the licensee, who occupied office space adjacent to a portable gauge storage location. The licensee had an area dosimeter/monitor to monitor the dose in the occupied office space. The annual doses are based on results from the area dosimeter/monitor and calculations to account for distance from the area dosimeter/monitor and time spent in the office.
"The devices stored in the portable gauge storage location include four Troxler model 3400 series devices housing 8 millicuries of Cs-137 and 40 millicuries of Am-241/Be, and two Instrotek model 3500 series devices housing 10 millicuries of Cs-137 and 40 millicuries of Am-241/Be.
"The discovery of the event was the result of a routine inspection conducted by the Department between February 6, 2025, and March 19, 2025. The Department and the licensee corresponded several times between March 19, 2025, and May 30, 2025, regarding the details of the event. The licensee made a determination on reporting applicability and submitted a written report on May 30, 2025.
"The licensee's corrective actions included moving the member of the public to another office away from potential exposure, restricting access to the office space adjacent to a portable gauge storage location, and adding additional shielding to the portable gauge storage location for adjoining offices and hallway."
South Carolina Event Number SC250004
The following information was provided by the South Carolina Department of Environmental Services (the Department) via phone and email:
"The licensee submitted a written report on May 30, 2025, indicating that the estimated total effective dose equivalent to an adult member of the public was determined to be 129 mrem/year for calendar year 2023 and 106 mrem/year for calendar year 2024. The licensee later submitted an updated calculation on June 17, 2025, indicating that the estimated total effective dose equivalent to an adult member of the public was determined to be 154 mrem/year for calendar year 2024.
"The member of the public was an employee of the licensee, who occupied office space adjacent to a portable gauge storage location. The licensee had an area dosimeter/monitor to monitor the dose in the occupied office space. The annual doses are based on results from the area dosimeter/monitor and calculations to account for distance from the area dosimeter/monitor and time spent in the office.
"The devices stored in the portable gauge storage location include four Troxler model 3400 series devices housing 8 millicuries of Cs-137 and 40 millicuries of Am-241/Be, and two Instrotek model 3500 series devices housing 10 millicuries of Cs-137 and 40 millicuries of Am-241/Be.
"The discovery of the event was the result of a routine inspection conducted by the Department between February 6, 2025, and March 19, 2025. The Department and the licensee corresponded several times between March 19, 2025, and May 30, 2025, regarding the details of the event. The licensee made a determination on reporting applicability and submitted a written report on May 30, 2025.
"The licensee's corrective actions included moving the member of the public to another office away from potential exposure, restricting access to the office space adjacent to a portable gauge storage location, and adding additional shielding to the portable gauge storage location for adjoining offices and hallway."
South Carolina Event Number SC250004
Power Reactor
Event Number: 57840
Facility: Browns Ferry
Region: 2 State: AL
Unit: [1] [2] [3]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Douglas Peterson
HQ OPS Officer: Sam Colvard
Region: 2 State: AL
Unit: [1] [2] [3]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: Douglas Peterson
HQ OPS Officer: Sam Colvard
Notification Date: 07/30/2025
Notification Time: 23:19 [ET]
Event Date: 05/30/2025
Event Time: 00:00 [CDT]
Last Update Date: 07/30/2025
Notification Time: 23:19 [ET]
Event Date: 05/30/2025
Event Time: 00:00 [CDT]
Last Update Date: 07/30/2025
Emergency Class: Non Emergency
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
Person (Organization):
Davis, Bradley (R2DO)
Davis, Bradley (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
| 2 | N | Y | 0 | Hot Shutdown | 100 | Power Operation |
| 3 | N | Y | 100 | Power Operation | 100 | Power Operation |
INVALID ACTUATION OF PRIMARY CONTAINMENT ISOLATION SYSTEM (PCIS) GROUP 6
The following information was provided by the licensee via phone and email:
"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system.
"On May 30, 2025, during de-inerting of the Unit 2 drywell for a forced outage, Unit 2 received a partial primary containment isolation system (PCIS) group 6 isolation. Additionally, standby gas treatment system (SGT) trains `B' and `C' auto started.
"Plant conditions which initiate PCIS group 6 and SGT actuations are reactor vessel low water level (Level 3), high drywell pressure, or reactor building ventilation exhaust high radiation (reactor zone or refuel zone). At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS and SGT was invalid.
"Upon investigation, a fuse was found to have failed as a result of a hot spot due to a corroded lug, which was the cause of the isolation. The fuse was replaced, [lug cleaned], condition was cleared, and all systems were realigned as necessary.
"There were no safety consequences or impact to the health and safety of the public as a result of this event.
"This event was entered into the Corrective Action Program as Condition Report 2017035.
"The NRC Resident Inspector has been notified of this event."
The following information was provided by the licensee via phone and email:
"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system.
"On May 30, 2025, during de-inerting of the Unit 2 drywell for a forced outage, Unit 2 received a partial primary containment isolation system (PCIS) group 6 isolation. Additionally, standby gas treatment system (SGT) trains `B' and `C' auto started.
"Plant conditions which initiate PCIS group 6 and SGT actuations are reactor vessel low water level (Level 3), high drywell pressure, or reactor building ventilation exhaust high radiation (reactor zone or refuel zone). At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS and SGT was invalid.
"Upon investigation, a fuse was found to have failed as a result of a hot spot due to a corroded lug, which was the cause of the isolation. The fuse was replaced, [lug cleaned], condition was cleared, and all systems were realigned as necessary.
"There were no safety consequences or impact to the health and safety of the public as a result of this event.
"This event was entered into the Corrective Action Program as Condition Report 2017035.
"The NRC Resident Inspector has been notified of this event."