Event Notification Report for September 04, 2026

AGREEMENT STATE REPORT - LOST EXIT SIGN

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

An exit sign was declared lost by the licensee on July 15, 2026. The exit sign is manufactured by Isolite Corporation (Model #: 880-12-6) with a total activity of 11.5 Ci of tritium (H-3).

Colorado Event Report ID Number: CO260021

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

PART 21 - BREAKERS NOT CLOSING

The following is a summary of information provided by Westinghouse Electric Company, LLC, via email:

Westinghouse has identified motor cutoff switches that were manufactured with an incorrect coating applied to the internal springs. The springs were specified to be colored with dye for identification during manufacturing. Contrary to this requirement, some springs were colored using acrylic paint which has the potential to generate foreign material inside the switch. Accumulation of the acrylic paint particles between moving and stationary contacts could increase contact resistance and prevent the switch from making electrical contact. The identified deviation does not adversely affect the ability of the breakers to open on demand.

This issue is associated with commercially dedicated motor cutoff switches manufactured by Homewood Products Corp. and supplied by Westinghouse as part number 3D51113G02Y as part of the following:

-- spare switch assemblies (4A48863G01Y)
-- new and refurbished DS breakers supplied by Westinghouse
-- refurbished DHP breakers supplied by Westinghouse
-- DS breaker refurbishment kits (4A48813G11Y)

Westinghouse recommends replacement of any switch with a safety function at the earliest allowable opportunity. For applications where the breaker's safety function is to open, Westinghouse recommends verification of the breaker closing circuit resistance.

Westinghouse has entered the deviation into their corrective action program with an overall due date for resolution in the first quarter of 2027. It includes actions to review and update the associated commercial dedication process to prevent recurrence. Westinghouse will also interface with its suppliers to address the use of dye instead of paint and request that corrective actions be implemented to prevent recurrence of this issue.

Potentially affected plants: Braidwood, Byron, Callaway, Catawba, Clinton, Columbia, Comanche Peak, Palo Verde, Seabrook, Sequoya, South Texas, Vogtle, and Wolf Creek

Contact information:
Andrew Bowman
Manager - Global Nuclear Regulatory Affairs
Westinghouse Electric Company LLC
1000 Westinghouse Drive
Cranberry Township, Pennsylvania 16066
Office: 412-374-2363

AGREEMENT STATE REPORT - DAMAGED MOISTURE DENSITY GAUGE

The following is a summary of information provided by the California Department of Public Health, Radiologic Health Branch (RHB) via email:

The licensee reported that on August 27, 2026, at approximately 0400 PDT, a Troxler model 3440 moisture density gauge (40 mCi Am-241/Be and 8 mCi Cs 137 sources, S/N 35929) fell from an operator's truck on CA State Route 163. The gauge and transport case were damaged, with the source rod and Cs-137 source detaching from the gauge. California Highway Patrol responded to provide traffic control and licensee staff recovered all parts of the gauge, including both sources, and the transport case. The licensee used lead shielding to reduce dose levels from the Cs-137 source to 10 mr/h at one foot, while the Am-241/Be source remained within the gauge shielding (gamma-only dose rate 0.04 mR/hr). The licensee's radiation safety officer (RSO) used a Type A case to transport the source rod and Cs-137 source to their office. Both sources were secured in the licensee's gauge locked area with additional concrete block shielding. An RHB inspector photographed both sources, collected wipe tests, and measured background survey levels (60 cpm).

RHB authorized returning the sources to Troxler following sealed source leak checks.

California 5010 number: 082726

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 is a summary of information provided by the Utah Division of Waste Management and Radiation Control (DWMRC) via email:

A potential overdose was identified by the radiation safety officer (RSO) on August 27, 2026, after a review of written directives; however, the doctor involved was unavailable. After the RSO talked to the doctor on August 28, 2026, they notified the DWMRC of the medical event that same day.

The intended treatment plan was to deliver 500 Gy to a 34 cc target volume.

The treatment calculation form indicated that the required activity was 0.379 GBq. A 3.0 GBq Y-90 vial was ordered and, at the time of administration, had decayed to approximately 1.824 GBq. Based on the licensee's current assessment, this resulted in an administered activity corresponding to approximately 457.9 percent of the prescribed dose after accounting for lung [shunt] fraction.

The licensee's preliminary review suggests the physician requested a vial with approximately two weeks of decay, but a vial with approximately one week of decay may have been supplied. The licensee continues to investigate the ordering, communication, and verification process to determine the exact cause of this discrepancy.

Event report ID number: UT26-0006

DWMRC plans to perform a follow-up visit for the incident next week.

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 - MEDICAL EVENT

The following is a summary of information provided by the Utah Division of Waste Management and Radiation Control (DWMRC) via email:

A potential overdose was identified by the radiation safety officer (RSO) on August 27, 2026, after a review of written directives; however, the doctor involved was unavailable. After the RSO talked to the doctor on August 28, 2026, they notified the DWMRC of the medical event that same day.

The patient had two treatment targets identified within the liver, referred to as the segment 5 and segment 6 targets.

Based on the licensee's current review, one target received approximately 111.7 percent of the intended 460 Gy prescribed dose, while the second target received approximately 160.8 percent of the intended 460 Gy prescribed dose.

The licensee's preliminary understanding is that the event may have resulted from confusion regarding use of the treatment planning spreadsheet between the authorized user and the supplier. It appears that each treatment target should have been planned on a separate worksheet, with each worksheet capable of accommodating up to three vials. In this instance, both treatment targets were entered sequentially on a single worksheet.

Because these worksheets serve as the written directive, correction of the worksheet calculations was required during the licensee's review. Once corrected, the resulting dose estimates for each target became apparent. The licensee is continuing to investigate this event and will provide a detailed explanation of the circumstances, contributing factors, and corrective actions in their formal written report.

DWMRC plans to perform a follow-up visit for the incident next week.

Event report ID number: UT26-0006

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 - ELLUATE EXCEEDED LIMIT

The following information was provided by the Texas Department of State Health Services (the Department) via phone and email:

"The Department received a notification from the licensee on August 28, 2026, at 1057 CDT, regarding a Mo-99 break-through on the first 2 elutions on a new 19 curie generator. The first elution exceeded 0.15 microcurie of Mo-99 per millicurie of Tc-99m. The second elution showed a break-through of 1.534 microcurie of Mo-99 per millicurie of Tc-99m.

"The generator was pulled from use for return to the manufacturer. No patient doses were dispensed.

"Additional Information will be provided in accordance with SA300 reporting requirements."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

Information on the manufacturer, model and serial number, and notifications made was not provided.

Texas incident number: 10322
NMED number: TX260035

RADIOGRAPHY SOURCE FAILED TO RETRACT

The following information was provided by the licensee via phone:

On August 28, 2026, at approximately 1530 CDT, the 83.9 Ci Ir-192 source on a QSA Global model 880 radiography camera (S/N D614) could not be retracted. After multiple attempts at retraction, the source eventually disconnected from the drive cable. On discovery of the disconnect, the source was driven into the collimator with temporary shielding placed to limit dose. A boundary to limit dose to less than 2 mrem per hour was established. Qualified source retrieval personnel cut the guide tube and discovered a burr on the interior of the tube that had prevented source retraction. The burr caused the source to disconnect from the drive cable following multiple attempts at retraction. No external wear or damage was noted on the drive cable or source connection.

The portion of the guide tube with the burr was removed and the clean-cut end of the guide tube was connected to the collimator. The source was then retracted back into the camera. The two radiographers that performed the source retraction received 45 mrem and 50 mrem, respectively.

MANUAL REACTOR TRIP

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

"At 0431 CDT on September 3, 2026, with Unit 2 in mode 1 at 100 percent power, the reactor was manually tripped due to indication of control rod movement and reactor protection system 'A' channel half scram, caused by nuclear instrumentation failure. The trip was not complex with all systems responding normally post-trip. 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).

"Operations responded using station operating procedures and stabilized the plant in mode 3, [hot shutdown]. Decay heat is being removed by using the main turbine bypass valves. Unit 3 is not affected.

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