Event Notification Report for November 24, 2025

AGREEMENT STATE REPORT - GAUGE SHUTTER FAILURE

The following information was provided by the Radiation Health Branch of the Kentucky Department for Public Health and Safety (The Department) via email:

"The Department was notified on 11/12/2025, by the radiation safety officer (RSO) from Big Rivers Electric Corporation, that during a routine six-month inventory/shutter checks, two sources were identified to have problems with the shutters closing.

"Both [gauges] measure density in the scrubber material and are mounted on piping. No exposure is possible unless the piping or gauge is removed. Primary action is to notify personnel and modify the red tag system to indicate that until this is resolved, no maintenance can be allowed on the piping because the shutters on the gauges cannot be safely closed.

"Until further notice, the piping where these gauges are mounted cannot have any maintenance activities performed on them. Red tag authorities should make note that the gauges cannot be red tagged because the shutters do not close.

"Maintenance will be performed on the gauges by an authorized contractor."

Gauge 1 information:
Manufacturer: Kay Ray
Model number: 20493
Serial number: 7062BP
Activity: 10 mCi Cs-137

Gauge 2 information:
Manufacturer: Ronan
Model number: SA8-C5
Serial number: 2104CP
Activity: 20 mCi Cs-137

AGREEMENT STATE REPORT - MEDICAL EVENT

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

"The University of California Los Angeles (UCLA) health [center] reported that a patient being treated for liver cancer underwent a Y-90 Sirtex SirSpheres brachytherapy treatment on November 12, 2025. This is a preliminary report of a medical event, per 10 CFR 35.3045.

"The authorized user's (AU) written directive called for two vials of Y-90 activity to treat two different segments of the right lobe via two different arterial branches of the lobe. The first prescription was for 108.11 mCi and 114 mCi (105.73 percent) was successfully delivered.
"The second prescription was for the right lobe, segment 4A using 13.51 mCi but only 10.04 mCi (74.32 percent) was able to be delivered.
"The authorized user believes his patient reached stasis, so he halted the procedure per the Sirtex IFU (instructions for use). Arterial flow is intermittently checked throughout the infusion process.
"The undelivered activity was determined by measuring the exposure rate at a known distance from the post-treatment waste after the administration. UCLA health [center] will submit a 15-day report to the Department."

California 5010 Number: 111225

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.

AUTOMATIC REACTOR TRIP

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

"At 1208 CST on 11/21/2025, with Unit 2 in Mode 1 at 100 percent power, [the] Unit 2 reactor automatically tripped due to a main transformer lockout. The trip was not complex, with all systems responding normally post-trip. One of three essential chillers (chiller 22C) was inoperable at the time of [the] trip due to planned maintenance activities. All other engineered safety feature (ESF) equipment was operable at the time of the event.

"Operations responded and stabilized the plant. Decay heat is being removed by steam generator pressure operated relief valves (PORV). There was no impact to Unit 1.

"All control rods fully inserted.

"Primary pressurizer PORV '655A' opened twice to relieve pressure in response to [the] pressure transient.

"[South Texas Project Unit 2] entered Technical Specification 3.8.1.1.e due to a loss of two off-site power sources, `A' and `C' ESF busses.

"Upon main turbine trip, throttle valves closed as expected.

"Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B).

"This event is also being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) due to valid actuation of two of the three emergency diesel generators.

"There was no impact on the health and safety of the public or plant personnel, and Unit 2 remains at normal operating temperature and normal operating pressure.

"The NRC Resident Inspector has been notified."


The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Emergency diesel generators '21' and '23' automatically started upon loss of power as expected. Auxiliary feedwater actuated post-trip as expected. Offsite power to ESF busses has been restored.

AGREEMENT STATE REPORT - LOST SOURCES

The following information was provided by the Illinois Emergency Management Agency (Agency) via phone and email:

"The Agency was contacted on November 17, 2025, to advise of four missing I-125 brachytherapy seeds with an activity of approximately 0.23 millicuries each. Three seeds remain missing with the most likely disposition being lost in transit from the Georgia shipper to the Illinois [common carrier] hub. The root cause appears to be poor packaging by the shipping licensee.

"On November 17, 2025, Bard Brachytherapy, Inc. received a package from Northside Hospital - Gwinnett (Lawrenceville, GA) with return shipping information indicating that there were twenty-four seeds being returned. Upon examination, ten were sealed inside their original packaging, nine were found loose inside the box, and one was found in the parking lot outside of the delivery door. Four sources remained unaccounted for when the Agency was contacted. [The common carrier] was called to return to the Bard facility, but surveys failed to identify any additional seeds within the delivery vehicle. Additional surveys were conducted at the local [common carrier] hub and on the truck that transported the package from O'Hare airport. The licensee was able to locate one additional seed at the [common carrier] hub, underneath a receiving conveyor belt, leaving three (3) seeds unaccounted for.

"The package is reported as having left Lawrenceville, GA on November 12, 2025. The package had no indication of damage from transit. The Georgia program will be notified. A similar incident was reported on May 13, 2024, as a result of inadequate packaging of seeds for transport by the same Georgia licensee. Agency outreach to O'Hare is still pending for additional surveys. A detailed listing of stops prior to delivery is also being sought.

"The brachytherapy seeds are classified as a Category 5 source, described by the IAEA as the least likely to be dangerous to a person. At the estimated activity, the exposure rate at one foot would be just under 0.5 mR/hour. Due to the small size as well as the proximity and duration of exposure required; it is highly unlikely any public exposures would exceed regulatory limits.

"The Illinois licensee followed reporting timelines, package receipt procedures, and performed all reasonable search efforts. Agency staff are pursuing additional avenues to attempt recovery of the sources. This report will be updated with any information available."

IL incident number: IL250045

* * * UPDATE ON NOVEMBER 19, 2025, AT 1653 EST FROM GARY FORSEE TO JORDAN WINGATE * * *

The following information was provided by the Illinois Emergency Management Agency (Agency) via email:

"Agency inspectors performed a reactive inspection at O'Hare airport on November 19, 2025. Search efforts located one of the three missing seeds, which will be returned to the Illinois licensee for disposal. Two I-125 brachytherapy seeds, containing approximately 0.23 mCi each, remain missing. A detailed listing of stops was obtained from the carrier but proved logistically impractical to fully survey (approximately 63 locations). Given the very low likelihood of public exposures exceeding any regulatory limit, the Category 5 classification of the sources, and high likelihood the remaining sources are out of state; the Agency is considering this matter closed."

Notified R3DO (Orlikowski) (email), NMSS Events Notification (email), and ILTAB (email).

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 - LOST CHROMATOGRAPH

The following is a summary of information provided by the Illinois Emergency Management Agency (Agency) via phone and email:

The licensee reported to the Agency that a generally licensed gas chromatograph could not be located. The device was listed as in use at the licensee's site in Lincolnwood, IL. No record could be found of the device's disposal, and search efforts have been unproductive. An investigation by the Agency is underway.

Device: Shimadzu Scientific Instrument ECD-17
S/N: 1721
Source: 10 mCi Ni-63
Source S/N: 618587

IL incident number: IL250046

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 - 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 three exit signs, each containing 17.51 Ci of tritium, were lost in Longmont, Colorado.

Manufacturer: SRB Technologies
Model number: BXU20GS

Colorado event number: CO250043

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 - 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 11.5 Ci of tritium, were lost in Allenspark, Colorado.

Manufacturer: Safety Light Corporation
Model number: 2040

Colorado event number: CO250044

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