| | Site | Start date | Title | Description |
|---|
| ENS 58049 | Limerick | 19 November 2025 08:28:00 | 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. |
| ENS 58027 | Southern California Edison Company | 5 November 2025 19:09:00 | Offsite Notification | The following information was provided by San Onofre Nuclear Generating Station (SONGS) via phone and email:
At 1109 PST, SONGS made (an) official notification to the (California) Department of Toxic Substance Control (DTSC) relating to one violation/citation non-minor, requiring corrective action related to the hazardous waste facility, permit CAD000630921.
Specifically, SONGS violated 22 California Code of Regulations (CCR) 66270.30(a) and California Health and Safety Code 25202(a), in that SONGS failed to comply with the conditions of the permit, specifically Part V `Special Conditions,' #5. To wit, DTSC inspectors observed the secondary containment which failed to be free of cracks or gaps in a waste management unit located in the (Hazardous Materials) Area - South Yard Facility (SYF), Section A.
During the physical inspection, the inspector noted holes were drilled into the slab (the containment system) of mixed waste/hazmat storage pad areas.
Because the identified holes only partially penetrate the secondary containment (i.e., the concrete pad), the secondary containment remains functional and intact and is sufficiently impervious to contain leaks, spills and accumulated precipitation.
SONGS is in discussions with DTSC to determine if the holes partially penetrating the pad exceed the permit requirement.
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
SONGS will notify NRC Region IV of this event. |
| ENS 57982 | Columbia | 13 October 2025 00:05:00 | Loss of Safety Function | The following information was provided by the licensee via phone and email:
On October 12, 2025, Columbia Generating Station (CGS) was performing a reactor building emergency cooling test. At 1428 (PDT), an air damper associated with the division 1 motor control center (MCC) room cooling failed to perform its intended function to close. This MCC supports the operation of one subsystem of the standby gas treatment system (SGT).
At 1440, a second air damper, associated with the division 2 MCC room cooling, also failed. This MCC supports the operation of the other SGT subsystem. Field operators were dispatched to investigate the potential cause.
At 1627, the first air damper that had failed was observed to have closed on its own without further operator action. Operators subsequently determined that failure of the air damper to close rendered the associated emergency room coolers inoperable.
At 1705, (the division 2 MCC) was declared inoperable and technical specification action statement 3.8.7.A was entered. From 1440 to 1627, CGS was in a condition that required both SGT subsystems to be declared inoperable due to the loss of emergency room cooling to their associated MCCs. This condition constitutes a loss of safety function of SGT and secondary containment. It could have challenged the station's ability to control a radioactive release had one occurred during that time.
This notification is being made pursuant to 10 CFR 50.72(b)(3)(v)(C) and (D) due to the loss of safety function of both trains of SGT and secondary containment for approximately 2 hours.
The Resident Inspector was notified.
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
At the time of notification, the licensee had exited all technical specification action statements.
- * * RETRACTION ON 11/5/2025 AT 1925 EST FROM JERRY AINSWORTH TO ERNEST WEST * * *
On October 12, 2025, at 2152 PDT, Columbia Generating Station notified the NRC pursuant to 10 CFR 50. 72(b)(3)(v)(C) and (D) due to the loss of safety function of both trains of standby gas treatment (SGT) and secondary containment for approximately 2 hours under Event Notification 57982.
The notification was made due to the failure of two dampers to close during testing of the Reactor Building Emergency Cooling System. The dampers that failed to close were cross-divisional and affected rooms with equipment necessary for both trains of the SGT system which supports the safety function of secondary containment.
Following the event, engineering conducted an evaluation to determine if both air dampers remaining open during a loss of cooling accident would have put any safety-related equipment at risk due to potential changes in radiological and environmental conditions within the associated motor control center (MCC) rooms.
The engineering evaluation determined temperatures and humidities would not have exceeded limits in the MCC rooms due to the dampers being left open. Additionally, any increase in radiation would be considered negligible and would not affect the ability of the equipment to perform their design functions. Therefore, the safety-related equipment within the MCC rooms would have been available and operable to perform their design function were an accident to occur. Consequently, the failure of two dampers to close during testing is not considered to be an event or condition that could have prevented fulfillment of the safety function of SGT and secondary containment and did not impact the ability to mitigate the consequences of an accident or control the release of radioactive material, therefore, event notification 57982 is retracted.
The Resident Inspector has been notified.
Notified R4DO (Vossmar) |
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