Event Notification Report for September 24, 2025

EN Revision Imported Date: 9/24/2025

EN Revision Text: PART 21 INTERIM REPORT OF DEVIATION

The following is a synopsis of information provided by Curtiss-Wright (CW) via email:

On 5/21/2025, Xcel Energy notified Curtiss-Wright about the failure of two NAMCO limit switches provided under CW project CJ21087 (tag number CJ2108701, serial numbers 01 and 04). The limit switches were dedicated by CW and shipped on 2/28/2025 to Xcel Energy. The switches failed a bench test performed by Xcel Energy, which aimed to verify that the contacts properly revert to their original state during spring return. Xcel Energy found that the contacts reverted to their original state prior to the audible click/snap, which is supposed to indicate contact changeover.

The two units were returned to Curtiss-Wright on 5/29/2025. The test result was fully duplicated on one of the switches. For the other switch (serial number 04), the switch contacts intermittently failed to return to the original state at all, requiring manual assistance to do so.

On 6/26/2025, CW sent the parts to NAMCO for repair. CW retested the parts after the repair. Part 04 still had the same issue with failing to reset as noted earlier. That limit switch was returned to NAMCO for a full evaluation.

CW anticipates an update to this notification with final results on 9/23/2025.

Potentially affected U.S. nuclear power plants: unknown at the time of the notification.

Contact Information:
Mark Papke
Quality Assurance Manager
Curtiss-Wright
4600 East Tech Drive
Cincinnati, OH 45245
mpapke@curtisswright.com

* * * UPDATE ON 9/23/25 AT 0850 EDT FROM CURTISS-WRIGHT TO KAREN COTTON * * *

The following information was provided by Curtiss-Wright (CW) via email:

On 6/26/2025 CW sent the relays to NAMCO for repair and the parts were returned to CW on June 26. CW retested the limit switches and one failed for the same issue as noted earlier, the failed limit switch was returned to NAMCO for a full evaluation.
The failure is still under investigation and CW has been in communication with NAMCO, the manufacturer.

Once the evaluation is complete this report will be updated. CW anticipates an update to this notification with final results on 11/24/2025.

Notified R3DO (Szwarc) and the Part 21/50.55 Reactors group

AGREEMENT STATE REPORT - STUCK OPEN GAUGE SHUTTER

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

"On September 16, 2025, the Department was notified by the licensee that the shutter on a Texas Nuclear model 5201 nuclear gauge had failed in the open position during routine testing. The gauge contains a 100 millicurie (original activity) cesium-137 source. Open is the normal operating position for the shutter. The licensee reported that there is no risk of additional radiation exposure to members of the general public or radiation workers due to this on/off mechanism failure. The licensee reported a service provider has been contacted to repair the gauge. Additional information will be provided as it is received in accordance with SA-300."

Texas incident number: 10228

AGREEMENT STATE REPORT - LOST CONTROL OF SOURCE

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

"On September 16, 2025, the Department was notified that on September 11, 2025, a radiographer was involved in a traffic accident while transporting an IR 100 radiography device containing a 45.7 curie iridium-192 source. The radiation safety officer (RSO) stated the radiographer hit another vehicle and then left the scene of the accident and went to their hotel. Someone provided the license plate number of the radiographer's truck to law enforcement. Law enforcement found the truck at the hotel, arrested the radiographer, and had the truck with the source transported to an impoundment yard. The truck was towed at 0300 CDT on September 12, 2025. The RSO was contacted by the impoundment yard, picked the truck up at 0830 that same morning, and returned the source to its storage location.

"The RSO stated that the locks on the darkroom door and the transportation box were still intact. The RSO does not believe any individual would have received an exposure due to this event.

"Additional information will be provided as it is received in accordance with SA-300."

Texas incident number: 10229

THIS MATERIAL EVENT CONTAINS A 'Category 2' LEVEL OF RADIOACTIVE MATERIAL

Category 2 sources, if not safely managed or securely protected, could cause permanent injury to a person who handled them, or were otherwise in contact with them, for a short time (minutes to hours). It could possibly be fatal to be close to this amount of unshielded radioactive material for a period of hours to days. These sources are typically used in practices such as industrial gamma radiography, high dose rate brachytherapy and medium dose rate brachytherapy. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

AGREEMENT STATE REPORT - NON-LICENSEE IN POSSESSION OF LICENSED MATERIAL

The following is a summary of information provided by the Florida Department of Health (the Department) via phone and email:

On September 15, 2025, US Customs and Border Protection (CBP) identified a Troxler model 3430 moisture density gauge (S/N 20331, 8 mCi Cs-137, 40 mCi Am-241/Be) in a vehicle leaving the Port of Jacksonville. CBP held the vehicle and determined that the company, RQ Construction Co., was not licensed to possess a gauge with this level of radioactivity. CBP notified the Department of the incident and contacted Troxler and arranged for transport of the gauge to Troxler's facility in North Carolina. The Department has learned that the model 3430 gauge was sent for calibration and leak testing at Troxler by a Florida-licensed company in Tampa, FL.

The Department has learned that RQ Construction Co. recently purchased a Troxler 4950 soil density gauge. This model of gauge does not require a radioactive materials license for possession and use. Troxler is investigating how the model 3430 gauge was returned to an unlicensed company in Jacksonville, FL.

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 - PACKAGE PRESUMED MISSING IN TRANSIT

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

"The Agency was contacted on 9/12/25 by Bard Brachytherapy (Carol Stream, IL) to advise that a package of (95) I-125 brachytherapy seeds, which they shipped on 9/9/25, had been repeatedly delayed and was now presumed lost at the carrier's hub in Kernersville, NC. Each seed contains 0.889 millicuries, for a total package activity of 84.455 millicuries. According to email transcripts, the [common] carrier stated the packages were still on site but had not been released for unknown reasons. There were no concerns of exposures to persons in unrestricted areas. On Tuesday, 9/16/25, the packages were then released and shipped to the intended recipient.

"It is unclear if the carrier declared the packages as lost and the reporting criteria in 10 CFR 20.2201 had been met. However, as the quantity of material would have required immediate reporting if lost. The licensee met all reporting requirements. This matter is now considered closed."

Item Number: IL250038

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 - CONTAMINATION DETECTED IN SHIPPING VIAL

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

"The Agency was contacted on September 8, 2025, by Bard Brachytherapy in Carol Stream, Illinois, to advise that they had detected contamination in a shipment of (72) TheraSeed Model 200 Pd-103 brachytherapy seeds. This is the second shipment of brachytherapy seeds since August, 2025, in which contamination was identified. The first occurrence identified contamination within the shipping vial and no leaking seeds. That occurrence failed to meet reportable criteria. Both shipments had been received directly from the manufacturer, Theragenics, in Georgia. The contamination did not result in any public or occupational exposures, nor were the licensee's facilities contaminated. However, based on additional information provided on September 11, 2025, this matter is reportable to the Agency under 32 Ill. Adm. Code 340.1230(a)(3)(A), the State's equivalent of 10 CFR 20.2203(a)(3)(i). The seeds have been returned to the manufacturer for investigation and to determine if a seed was leaking or there is a repeat instance of a contaminated shipping vial.

"Details: The shipment consisted of (72) sources at 1.55 millicuries each, for a total consignment of 267.3 millicuries. The brachytherapy seeds are TheraSeed model 200's, under registry number NR-0645-S-101-S. Upon receipt and transfer of brachytherapy seeds to a sterile area, the Illinois licensee surveys the empty shipping vial. It is in this step they identified contamination, later quantified to be approximately 0.013 microcuries. The reportability stems from the fact their license requires testing for contamination prior to incorporating the sources into an implanting device. The reporting threshold is 0.005 microcuries, and thus, this represented the presence of contamination in a restricted area breaching an applicable limit in the license. It is noteworthy a previous incident reported to the Agency on August 21, 2025, also found contamination in a shipping vial, although it did not exceed 0.005 microcuries. The Georgia program was contacted and notified of the incident as well. The licensee met applicable reporting timelines. This report will be updated with any additional information provided by the manufacturer."

Item Number: IL250039

AGREEMENT STATE REPORT - DAMAGED GAUGE

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

"On September 17, 2025, the Department received a report from the licensee stating that, during routine testing, the screw for the shutter operating arm on a Ronan SA-1-F37 nuclear gauge containing a 100 millicurie (original activity) cesium-137 source had broken. The shutter is stuck in the open position. Open is the normal operating position. The licensee stated they will contact a service provider to repair the gauge.

"The licensee reported that there is no risk of additional radiation exposure to members of the general public or radiation workers, due to this on/off mechanism failure. The licensee reported a service provider has been contacted to repair the gauge.

"Additional information will be provided as it is received in accordance with SA-300."

Texas Incident Number: 10230
Texas NMED Number: TX250049

PROHIBITIED SUBSTANCE DISCOVERED WITHIN THE PROTECTED AREA

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

"At approximately 1030 EDT on September 22, 2025, it was determined an employee had an unopened bottle of beer inside the protected area on September 20, 2025. The individual's authorization for site access has been restricted, pending the results of an investigation."

The NRC Resident Inspector and the NRC Region III Security Inspector have been notified.

FITNESS FOR DUTY EVENT

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

"On 9/22/25, Watts Bar Nuclear (WBN) Operations was informed that a WBN licensed operator had tested positive for a controlled substance during a pre-screening test to regain unescorted access, in violation of the Tennessee Valley Authority (TVA) fitness for duty policy.

"A pre-access screening was completed on 9/16/25 to regain unescorted access. The results were sent to the TVA medical review officer on 9/22/25. The test was declared positive for a controlled substance and WBN Operations was notified at 1500 EDT on 9/22/25.

"The individual's unescorted access remains revoked.

"The NRC Resident Inspector has been notified."

FITNESS FOR DUTY EVENT

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

"At 1300 CDT on September 15, 2025, it was determined that a non-licensed supervisor had tested positive for a controlled substance, in violation of South Texas Project's fitness for duty policy. Prior to this, the individual's unescorted access had been administratively withdrawn pending retesting. This is reportable under 10 CFR 26.719 and is a late 24-hour notification.

"The NRC Resident Inspector has been notified."

AGREEMENT STATE REPORT - LOST GAS CHROMATOGRAPHY DEVICES

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

"As a result of an ongoing investigation into unresponsive general licensees, the Agency became aware that five (5) generally licensed Perkin-Elmer model n610-0063 gas chromatography devices, each containing 15 millicuries of Ni-63, are missing.

"Reportedly, in late 2024, the licensee went through a transition of layoffs and is currently being bought by another company. Due to the change in employees, the location of these devices is unknown.

"The licensee failed to properly transfer or dispose of the devices (serial numbers 4377, 6055, 6273, 6202, and 7067). The facility manager is currently trying to reach out to past employees for information. The Agency has reached out to the distributor to try and locate the devices.

"The quantity of radioactive material involved, while unlikely to be dangerous to the public, is reportable within 30 days to the Agency and the U.S. NRC. Investigation is ongoing, and any updates will be reported."

Illinois Event Number: IL250040

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 Radiation Health Branch of the Kentucky Department for Public Health and Safety (KY RHB) via email:

"KY RHB was notified on 9/18/2025 by the radiation safety officer (RSO) from the University of Louisville Hospital of an issue with five Sir-Sphere Y-90 doses.

"Due to a software issue that had a calculation error converting GBq to mCi, 5 patients were underdosed to a point that their dose was more than 20 percent outside of the prescribed dose, and the dose to the organ (liver) was more than 50 mSv from the prescribed dose.

"The RSO is meeting with the physician today to discuss the issues. The issue with the software has been fixed."

KY Event Number: TBD

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.

NON-POWER REACTOR - UNPLANNED HIGH-POWER TRIP

The following information was summarized from the licensee via phone and email:

On September 24, 2025, at 1511 MDT, a high-power trip occurred (operation of safety channels 2 and 3). The reactor was being operated by a senior reactor operator (SRO) and a student authorized operator. A positive-period excess reactivity measurement was being performed. The reactor power rose to 5.64 watts. The technical specifications power limit of 6 watts plus was not exceeded, and both safety channels functioned to shut the reactor down.

This prompt notification for a high-power trip is in accordance with current procedures and technical specification 6.9.2.a.7. The proximate cause of this event was operator distraction. The reactor room had two visitors at the time of the event, an NRC inspector and a University of New Mexico nuclear engineering instructor. The instructor was engaging the student authorized operator and the SRO on matters relating to a laboratory activity ongoing in another part of the building. The SRO responded to the rising power too slowly to avoid the high-power trip.

AUTOMATIC REACTOR TRIP

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

"On September 24, 2025, at 1347 CDT, Arkansas Nuclear One, Unit 1, (ANO-1) experienced an issue with the X-01B main phase transformer which led to an automatic trip on reactor protection system (RPS).

"ANO-1 is currently stable in mode 3, maintaining pressure and temperature with the P-1A and P-1B main feedwater pumps and steaming to the main condenser. All rods inserted and systems functioned as expected.

"There is no radiological release on either unit as a result of this event.

"This report satisfies the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A) for the reactor protection system actuation.

"The NRC Senior Resident Inspector has been notified.

"Unit 2 was not affected."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
ANO-1 retains access to all normal sources of offsite power.

MANUAL REACTOR TRIP

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

"On September 24, 2025, at 1829 CDT, Comanche Peak, Unit 1, was manually tripped due to a trip of both main feed water (MFW) pumps. All auxiliary feedwater pumps started due to the trip of both MFW pumps. This event is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B) for a reactor trip and 10 CFR 50.72(b)(3)(iv)(A) for an actuation of auxiliary feedwater. Unit 1 is being maintained in mode 3 in accordance with integrated plant operating procedures. Decay heat is being rejected to the main condenser via the steam dump valves. The cause of both MFW pumps tripping is unknown and under investigation.

"The NRC Resident Inspector was notified."


The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
No evolutions were ongoing at the time of the event.