Event Notification Report for November 05, 2025

AUTOMATIC EMERGENCY DIESEL GENERATOR ACTUATION

The following information was provided by the licensee via phone and email:

"At 1003 Central Standard Time (CST), with [Unit 1] in mode 5 at 0 percent power, an actuation of the 'A' emergency diesel generator (EDG) occurred when energizing main transformers from the switchyard for post-installation soak. The energization was coordinated with transmission system operators using approved procedures, however, grid conditions external to the substation allowed the voltage to drop below the NB01 undervoltage relay setpoint. The EDG automatically started as designed and picked up the loads on the NB01 bus. All safety systems responded as designed. Substation parameters immediately recovered to normal values, and all systems were restored to [normal] standby conditions.

"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 'A' EDG. There was no impact on the health and safety of the public or plant personnel.

"The NRC Resident Inspector has been notified."

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.

AGREEMENT STATE REPORT - LOST EXIT SIGNS

The following is a summary of information provided by the Colorado Department of Public Health and Environment via email:

The licensee reported two exit signs, each containing 6.0 Ci of tritium, were lost in Commerce City, Colorado.

Manufacturer: Isolite Corporation
Model Number: SLX60

Colorado Event Number: CO250042

THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL

Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf