Event Notification Report for June 17, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
06/16/2025 - 06/17/2025
Power Reactor
Event Number: 57763
Facility: Grand Gulf
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Alex Shetter
HQ OPS Officer: Brian P. Smith
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Alex Shetter
HQ OPS Officer: Brian P. Smith
Notification Date: 06/17/2025
Notification Time: 08:16 [ET]
Event Date: 06/17/2025
Event Time: 04:26 [CDT]
Last Update Date: 06/17/2025
Notification Time: 08:16 [ET]
Event Date: 06/17/2025
Event Time: 04:26 [CDT]
Last Update Date: 06/17/2025
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):
Drake, James (R4DO)
Drake, James (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 70 | Power Operation | 0 | Hot Shutdown |
MANUAL REACTOR SCRAM
The following information was provided by the licensee via phone and email:
"On June 17, 2025, at 0426 CDT, Grand Gulf Nuclear Station (GGNS) was operating at 70 percent power when a manual scram was initiated due to degraded main condenser vacuum caused by the loss of the 'A' circulating water pump.
"All control rods fully inserted, there were no complications, and all plant systems responded as designed. Immediately after the scram, an expected reactor water Level 3 isolation signal was received. Reactor pressure is being maintained via the turbine bypass valves. Reactor level is being maintained via main feedwater. GGNS is currently in Mode 3. No radiological releases have occurred due to the event.
"The cause of the circulating water pump trip is under investigation.
"The manual reactor protection system actuation is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B). The expected reactor water Level 3 isolation signal is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"The NRC Resident Inspector was notified."
The following information was provided by the licensee via phone and email:
"On June 17, 2025, at 0426 CDT, Grand Gulf Nuclear Station (GGNS) was operating at 70 percent power when a manual scram was initiated due to degraded main condenser vacuum caused by the loss of the 'A' circulating water pump.
"All control rods fully inserted, there were no complications, and all plant systems responded as designed. Immediately after the scram, an expected reactor water Level 3 isolation signal was received. Reactor pressure is being maintained via the turbine bypass valves. Reactor level is being maintained via main feedwater. GGNS is currently in Mode 3. No radiological releases have occurred due to the event.
"The cause of the circulating water pump trip is under investigation.
"The manual reactor protection system actuation is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B). The expected reactor water Level 3 isolation signal is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"The NRC Resident Inspector was notified."
Power Reactor
Event Number: 57766
Facility: LaSalle
Region: 3 State: IL
Unit: [1] [2] []
RX Type: [1] GE-5,[2] GE-5
NRC Notified By: Brock Pollmann
HQ OPS Officer: Ernest West
Region: 3 State: IL
Unit: [1] [2] []
RX Type: [1] GE-5,[2] GE-5
NRC Notified By: Brock Pollmann
HQ OPS Officer: Ernest West
Notification Date: 06/17/2025
Notification Time: 18:03 [ET]
Event Date: 06/17/2025
Event Time: 12:57 [CDT]
Last Update Date: 06/17/2025
Notification Time: 18:03 [ET]
Event Date: 06/17/2025
Event Time: 12:57 [CDT]
Last Update Date: 06/17/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
Person (Organization):
Zurawski, Paul (R3DO)
Zurawski, Paul (R3DO)
| 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 | 100 | Power Operation | 100 | Power Operation |
UNPLANNED MAINTENANCE OF TECHNICAL SUPPORT CENTER SUPPLY FAN
The following information was provided by the licensee via phone and email:
"This is an eight-hour, non-emergency notification for a loss of emergency assessment capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the technical support center (TSC) supply fan belt failed [at approximately 1257 CDT on 6/17/2025] which affects the functionality of an emergency response facility.
"Corrective maintenance activities have been completed as of 6/17/25 at 1619 [CDT] to replace the TSC supply fan belt. The TSC supply fan has been re-started and this condition is no longer applicable.
"If an emergency would have been declared requiring TSC activation during this period, the TSC would have been staffed and activated using existing emergency planning procedures unless the TSC became uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC were necessary, the Emergency Director would have relocated the TSC staff to an alternate location in accordance with applicable site procedures. The emergency response organization team was notified of the maintenance and the possible need to relocate during an emergency.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
The following information was provided by the licensee via phone and email:
"This is an eight-hour, non-emergency notification for a loss of emergency assessment capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the technical support center (TSC) supply fan belt failed [at approximately 1257 CDT on 6/17/2025] which affects the functionality of an emergency response facility.
"Corrective maintenance activities have been completed as of 6/17/25 at 1619 [CDT] to replace the TSC supply fan belt. The TSC supply fan has been re-started and this condition is no longer applicable.
"If an emergency would have been declared requiring TSC activation during this period, the TSC would have been staffed and activated using existing emergency planning procedures unless the TSC became uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC were necessary, the Emergency Director would have relocated the TSC staff to an alternate location in accordance with applicable site procedures. The emergency response organization team was notified of the maintenance and the possible need to relocate during an emergency.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."