Event Notification Report for March 14, 2025

AUTOMATIC START OF THE DIVISION III EMERGENCY DIESEL GENERATOR

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

"On March 15, 2025, at 1248 CDT, Grand Gulf Nuclear Station (GGNS) was operating in mode 1 at 100 percent reactor power when a grid disturbance (degraded voltage) resulted in a valid specified system actuation (automatic start) of the division Ill emergency diesel generator (EDG). The division Ill EDG started and repowered the '17' AC safety-related electrical bus as designed.

"GGNS is currently in mode 1 at 100 percent reactor power. No radiological releases have occurred due to this event and no other safety system actuations occurred.

"This event is being reported under 10 CFR 50.72(b)(3)(iv)(A), as an event or condition that results in a valid specified system actuation due to the automatic start of the division Ill EDG on bus undervoltage due to a grid disturbance.

"The NRC Senior Resident Inspector has been notified."

AGREEMENT STATE REPORT - LOST TRITIUM EXIT SIGN

The following information was provided by the California Department of Public Health via email:

"On Monday, March 17, 2025, the California State University - Long Beach alternate radiation safety officer reported the loss of one tritium exit sign from their campus' Carpenter Performing Art Center. This exit sign was an Isolite tritium exit sign, made on April 5th, 2015, Model 2000, S/N H50630, with an initial tritium activity of 0.281 TBq (7.6 Ci). The exit sign was officially declared lost on March 14, 2025, after a thorough search by campus environmental health and safety personnel could not locate the exit sign. A contamination survey of the exit sign's designated location did not show the presence of tritium contamination. The licensee will continue to look for the exit sign and provide additional information when available. Corrective actions included refresher training, increased physical inventories of all campus tritium exit signs, and review of methods of securing of exit signs to mounting surfaces."

California 5010 number: 031725

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

AGREEMENT STATE REPORT - MEDICAL EVENT

The following information was provided by the New Mexico Environment Department, Radiation Control Bureau via email:

"The New Mexico Environment Department, Radiation Control Bureau was informed of a medical event at approximately 1605 MDT on Friday, March 14, 2025.

"Incident date: March 4, 2025. Discovery date: March 14, 2025.

"Lovelace Medical Center, license number (MI210)
"Prescribed Activity: 0.5 GBq
"Delivered Activity: 0.4 GBq
"Percent Delivered: -20 percent
"Possible cause: low dose prescribed and/or possible issues with the catheter.

"The facility stated they are working on the 15-day report."

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

AGREEMENT STATE REPORT - CRIMPED SOURCE GUIDE TUBE

The following information was provided by the California Department of Public Health, Radiologic Health Branch via email:

"A reciprocity licensee, Stronghold Inspection (TX license number L06918), was conducting industrial radiography at a laydown yard located on the Martinez Refining Company site (RML #3590). At about 0200 PDT, a pipe that was being radiographed rolled onto the guide tube of the exposure device (QSA Global 880 Delta, s/n D17238), crimping the guide tube and preventing the 2.73 TBq Ir-192 sealed source (QSA Model 8424-9, s/n 12805P) from retracting into its shielded position. The licensee reports that a perimeter spanning about 200 feet in radius was established. The exposure rate at the perimeter is less than 2 mR/hr and is under constant surveillance. The source is currently located in the collimator at the end of the guide tube. The licensee has requested the assistance of QSA's source retrieval team. Source retrieval is scheduled to begin upon arrival at approximately 1800 PDT. RHB inspectors arrived onsite at about 1000 PDT and will observe the operations until the source has been secured."

California 5010 number: 031425

60-DAY OPTIONAL TELEPHONIC NOTIFICATION FOR AN INVALID CONTAINMENT ISOLATION

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

"On March 14, 2025, at 1523 EST, while Unit 1 was operating at 99.5 percent power in mode 1, the unit experienced a loss of the 24/48V DC bus (division 2) due to a failed battery charger. The 24/48V DC bus was restored by installing a temporary charger.

"This event is reportable per 10 CFR 50.73(a)(2)(iv)(A) because it was not part of a pre-planned sequence and resulted in the invalid, partial actuation of containment isolation valves (CIVs) in both the primary containment and secondary containment systems, with all systems responding normally.

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."