Event Notification Report for November 19, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/18/2025 - 11/19/2025
EVENT NUMBERS
58049
58049
Power Reactor
Event Number: 58049
Facility: Limerick
Region: 1 State: PA
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Derek Herr
HQ OPS Officer: Robert A. Thompson
Region: 1 State: PA
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Derek Herr
HQ OPS Officer: Robert A. Thompson
Notification Date: 11/19/2025
Notification Time: 11:19 [ET]
Event Date: 11/19/2025
Event Time: 03:28 [EST]
Last Update Date: 11/19/2025
Notification Time: 11:19 [ET]
Event Date: 11/19/2025
Event Time: 03:28 [EST]
Last Update Date: 11/19/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(C) - Pot Uncntrl Rad Rel
10 CFR Section:
50.72(b)(3)(v)(C) - Pot Uncntrl Rad Rel
Person (Organization):
Lilliendahl, Jon (R1DO)
Lilliendahl, Jon (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 10 | Power Operation |
LOSS OF REACTOR ENCLOSURE RECIRCULATION
The following is a summary of information provided by the licensee via phone and email:
On November 18, 2025, at 0328 CST, as the licensee was initiating the standby gas treatment system in support of planned maintenance on normal reactor building ventilation, the '2A' reactor enclosure recirculation system (RERS) fan failed to establish flow upon the system initiation signal. The '2B' RERS fan was previously inoperable due to a planned maintenance window. Technical specification action statement 3.6.5.4.B was entered with both Unit 2 RERS fans inoperable. The '2B' RERS fan was restored to operable at 0523 EST. The licensee returned normal reactor building ventilation to service to restore secondary containment differential pressure.
Due to inoperability of both RERS trains, 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).
The licensee reported there was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector was notified.
The following is a summary of information provided by the licensee via phone and email:
On November 18, 2025, at 0328 CST, as the licensee was initiating the standby gas treatment system in support of planned maintenance on normal reactor building ventilation, the '2A' reactor enclosure recirculation system (RERS) fan failed to establish flow upon the system initiation signal. The '2B' RERS fan was previously inoperable due to a planned maintenance window. Technical specification action statement 3.6.5.4.B was entered with both Unit 2 RERS fans inoperable. The '2B' RERS fan was restored to operable at 0523 EST. The licensee returned normal reactor building ventilation to service to restore secondary containment differential pressure.
Due to inoperability of both RERS trains, 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).
The licensee reported there was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector was notified.