Event Notification Report for October 10, 2025

EN Revision Imported Date: 10/10/2025

EN Revision Text: AGREEMENT STATE REPORT - LOST RADIATION SHIELD

The following information was provided by the Florida Bureau of Radiation Control (BRC) via email:

"BRC received notification from Orlando Health on September 30, 2025, that a depleted uranium shield [weighing 120lbs] was disposed of alongside its Nuclear Medicine Adac Camera model MCD/AC. It was last accounted for in 2014. The shield was likely disposed of [during] the decommission and removal of the camera. No records of the [shield] removal are available."

FL Incident #: FL25-097

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 - DAMAGED MOISTURE DENSITY GAUGE

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

"The licensee had an InstroTek portable gauge containing 10 mCi Cs-137 and 40 mCi Am-241/Be sealed sources at a temporary jobsite. The gauge was run over by a compaction roller. The work site was cordoned off and the roller shut off. The roller [pushed] the rod with the Cs-137 source out of the shielded position and into the ground. The local radiation safety officer responded to the site. They maintained the cordoned off area until they were able to secure the gauge. The gauge was packaged and labeled according to the manufacturer's instructions and returned to the licensee's storage location. The accident area was surveyed after the gauge was secure and the readings were at background. The licensee leak tested the sources and sent them in to be analyzed."

State event report ID: MN250006

AGREEMENT STATE REPORT - STUCK OPEN GAUGE SHUTTER

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

During routine gauge shutter checks conducted by the licensee on October 2, 2025, the licensee found the shutters of three Berthold Technologies model LB300L fixed gauges stuck in the open position. The licensee has flagged the gauges, placed barriers around the gauges, and suspended any work in the area. The licensee is arranging for a Berthold field representative to perform maintenance on the gauges to attempt to close the gauges.

Gauge 1: 0.2 mCi Co-60
Gauge 2: 0.5 mCi Co-60
Gauge 3: 1.8 mCi Co-60

Arkansas event: AR-2025-013

AGREEMENT STATE REPORT - MEDICAL EVENT

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

"On October 3, 2025, the Department received notification from the licensee regarding a treatment error during stereotactic radiosurgery with a gamma knife system for a patient with a brain arteriovenous malformation (AVM). The patient was prescribed a total dose of 20 Gy over 2 fractions. The licensee stated that the event occurred on September 25, 2025, when during the first fraction, a coordinate system error between the stereotactic frame and immobilization masking resulted in radiation being delivered to an incorrect site in the brain, completely missing the AVM target volume. As a result, the prescribed 12 Gy for the first fraction was delivered to non-target brain tissue and 0 Gy reached the intended AVM target. The error was discovered on October 2, 2025, just before the patient was scheduled to undergo the second and final treatment fraction. Treatment was immediately suspended and both the referring physician, who is the surgeon, and the patient were immediately informed.

"Additional information will be provided in accordance with SA-300 reporting requirements."

Texas incident number: 10231

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.

MANUAL REACTOR SCRAM

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

"On October 9, 2025, at 1207 CDT, River Bend Station (RBS) was operating at 100 percent reactor power when a manual reactor protection system (RPS) actuation was inserted as a result of a division-I balance of plant (BOP) isolation. The BOP isolation was a result of a blown fuse during surveillance activity. The BOP isolation resulted in the loss of instrument air system (IAS) and component cooling primary system (CCP) to containment.

"Following the isolation, control room operators entered the applicable abnormal operating procedures (AOP). In accordance with AOP guidance, control room operators inserted a manual reactor scram. All plant systems responded as designed. Immediately after the scram, a reactor water level 3 isolation signal was received as expected.

"Due to the swell from the main turbine trip, a reactor water high level 8 actuation signal was received at 1208 CDT. The level 8 actuation signal was reset at 1211 CDT. At 1237 CDT, control room operators entered the emergency operating procedure (EOP) for high containment pressure. The increase in containment pressure was due to the isolation of the containment vent flow path.

"The isolation signal for IAS and CCP was reset at 1255 CDT. Following the restoration of the isolation signal, control room operators lowered containment pressure and exited the EOP at 1305 CDT.

"Reactor pressure is being maintained by the main turbine bypass valves. Reactor level is being maintained by condensate and main feedwater. RBS is currently in mode 3. No radiological releases have occurred due to this event.

"The event is being reported under 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A) as an event or condition that results in actuation of the RPS when the reactor is critical and as a specified system actuation due to the expected reactor water level 3 isolation signal immediately following the reactor scram, and a subsequent level 8 signal.

"The NRC Resident Inspector has been notified."

AGREEMENT STATE REPORT - STOLEN MOISTURE DENSITY GAUGE

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

"On October 6, 2025, at approximately 0900 CDT, the Department received a call from the radiation safety officer (RSO) to report a moisture density gauge was stolen from a company vehicle parked in a gated parking lot at a hotel in Houston. The RSO stated the gauge was chained and locked inside the cab of the vehicle. The RSO stated the handles were pulled from the transport case. The unit is a Troxler model 3440 (S/N 30621) containing a Cs-137 source of 8 mCi and an Am-241/Be source of 40 mCi.

"Additional information will be provided in accordance with SA-300 Reporting requirements."

Texas incident number: 10232

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 - DAMAGED MOISTURE DENSITY GAUGE

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

"On October 6, 2025, at 1324 CDT, the Department was notified by the licensee's radiation safety officer (RSO) that while performing a measurement with a Troxler model 3440 moisture/density gauge, the technician was struck and killed by a piece of equipment. The gauge contains a 40 millicurie americium-241 source and a 9 millicurie cesium-137 source. The gauge appeared to have some minor damage. The RSO stated the gauge was picked up by a member of the HAZMAT team and placed on the tailgate of the licensee's truck. It was noted that the cesium source was sticking out of the bottom of the gauge about 2 inches. The HAZMAT team reported to the RSO the dose rate at 5 feet from the gauge was reading 5 rem per hour. (Calculation of the gamma dose from the cesium source at 5 feet would be 1.24 millirem/hr.). The RSO stated he had personnel and equipment at the site to measure the dose rate, but the emergency response personnel would not let them enter the area. The RSO stated they had evacuated all personnel out to 100 feet.

"At 1422 CDT, the RSO reported the police allowed them to enter the area and perform a radiation survey. The RSO reported their survey showed less than 1 millirem per hour at 5 feet from the gauge. The RSO stated they placed the gauge into the transport case and then into the steel security box in the truck bed to transport the gauge back to their office. The gauge will be sent to the manufacturer for inspection.

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

Texas incident number: 10233

AGREEMENT STATE REPORT - MEDICAL EVENT

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

"On October 6, 2025, the Department received notification from the licensee regarding a treatment error during stereotactic radiosurgery with the gamma knife system for a patient with a brain arteriovenous malformation (AVM). The patient was prescribed 2 treatment sessions of 12 Gy each. The licensee stated that an error during the transfer from the frame coordinate system to the mask coordinate system resulted in radiation being delivered to an incorrect site in the brain. As a result, the dose delivered to the treatment site was less than the prescribed dose. The licensee stated that the event occurred in February 2025 and was discovered by the radiation oncology team during an internal review exercise of all AVM treatments provided by the licensee since 2016. This review was initiated following a similar incident involving the same procedure which the licensee had previously discovered on October 2, 2025, and reported to the Department on October 3, 2025 (see EN 57966). The licensee conducted this review to determine whether other patients had been affected by the same system error. According to the licensee, out of all cases reviewed, only this one met the criteria to be classified as a reportable event.

"Additional information will be provided in accordance with SA300 Reporting requirements."

Texas incident number: 10235

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 - LOST SOURCES

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

"On October 6, 2025, the Agency received notification from the licensee on missing calibration sources. The sources include 2 vials of cesium-137 and cobalt-57. The licensee could not provide details regarding the activities of the sources. According to the licensee, on November 26, 2024, the sources were shipped using [common carrier] to Eckert and Ziegler in California for disposal. At the time, the licensee reportedly they were in the process of closing-up as it was merging with another organization. The licensee stated that it had submitted a request for termination of its license to the Agency's licensing department. In March 2025, the licensing department requested radioactive source transfer records as part of the license termination process, but the licensee could not provide any documentation. The licensee stated that these records could not be found and were lost during the changeover to the new company. Eckert and Ziegler was also contacted but could not find any record of receipt of these sources.

"Additional information will be provided in accordance with SA 300 reporting requirements."

Texas Incident Number: 10236

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

MANUAL REACTOR TRIP

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

"At 0100 EDT, on 10/10/2025, with McGuire Unit 2 in mode 1 at 5 percent power, the reactor was manually tripped due to an approximate 4 gpm leak associated with the chemical and volume control system. The motor driven auxiliary feedwater pumps were manually started due to anticipation of automatic actuation. The trip was uncomplicated with all systems responding normally post-trip.

"Due to the reactor protection system actuation while critical and manual start of the motor driven auxiliary feedwater pumps, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B), and an eight-hour system actuation per 50.72(b)(3)(iv)(A).

"At 0211 on 10/10/25, it was determined the required train of the refueling water storage tank was inoperable due to insufficient borated water volume; therefore, this condition is also being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v). The safety function was restored at 0249 on 10/10/2025 and the required train has been declared operable. There was no impact to the other unit.

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

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Decay heat is being removed via steam dump valves to the main condenser, and the auxiliary feedwater system. The cause of the leak is being investigated.

DEGRADED CONTROL ROD DRIVE MECHANISM PENETRATION

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

"At 0230 CDT, on October 10, 2025, it was determined that the control rod drive mechanism (CRDM) penetration '69' was degraded because liquid penetrant testing performed on the embedded flaw repair weld identified an unacceptable indication in accordance with American Society of Mechanical Engineers (ASME) Section Ill acceptance standards and NRC approved licensee relief request for a previously performed embedded flaw repair. Therefore, this event is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(ii)(A).

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

PART 21 - POSITIVE BATTERY POST SEPARATION

The following is a summary of information provided by Paragon Energy Solutions via email:

In May 2025, Quad Cities experienced positive battery post separation from three cells in a safety related battery string at the post seal nut region. Paragon dispatched engineering resources to provide technical assistance to the station during battery string replacement and to perform an initial assessment of the condition. The current postulated cause of the post separation is due to a corrosion mechanism that is still under investigation. In September 2025, Calvert Cliffs reported separation of a positive post from a cell upon initiation of a service test discharge resulting in electrical arcing at the cell post area.

Paragon has not yet identified a defect in the cell post design or manufacturing process which, if corrected, would prevent or mitigate this condition. The affected battery cells have been in service for 14 years and 11 years, respectively. This phenomenon only affects the positive posts on the battery, and the area of the post where corrosion occurs is not visible during routine inspection. Paragon is not stipulating that high cell voltage is the primary indication of the corrosive effect in the positive post, but this indication may allow sites to ensure cells are adequately evaluated for post integrity. Paragon recommends licensees continue normal battery maintenance procedures contained in station instructions.

Affected Plants
Region 1 - Beaver Valley, Calvert Cliffs, Fitzpatrick, Ginna, Millstone, Nine Mile Point, Seabrook
Region 2 - Brunswick, Catawba, McGuire, Robinson, Shearon Harris, Turkey Point
Region 3 - Davis Besse, Dresden, LaSalle, Quad Cities
Region 4 - Callaway, Comanche Peak, Palo Verde, River Bend, South Texas Project

Paragon Contact Information:
Richard Knott
Vice President, Quality Assurance
(518) 450-9706 (C)

LOSS OF SAFETY FUNCTION

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

"On October 12, 2025, Columbia Generating Station (CGS) was performing a reactor building emergency cooling test. At 1428 [PDT], an air damper associated with the division 1 motor control center (MCC) room cooling failed to perform its intended function to close. This MCC supports the operation of one subsystem of the standby gas treatment system (SGT).

"At 1440, a second air damper, associated with the division 2 MCC room cooling, also failed. This MCC supports the operation of the other SGT subsystem. Field operators were dispatched to investigate the potential cause.

"At 1627, the first air damper that had failed was observed to have closed on its own without further operator action. Operators subsequently determined that failure of the air damper to close rendered the associated emergency room coolers inoperable.

"At 1705, [the division 2 MCC] was declared inoperable and technical specification action statement 3.8.7.A was entered. From 1440 to 1627, CGS was in a condition that required both SGT subsystems to be declared inoperable due to the loss of emergency room cooling to their associated MCCs. This condition constitutes a loss of safety function of SGT and secondary containment. It could have challenged the station's ability to control a radioactive release had one occurred during that time.

"This notification is being made pursuant to 10 CFR 50.72(b)(3)(v)(C) and (D) due to the loss of safety function of both trains of SGT and secondary containment for approximately 2 hours."

The Resident Inspector was notified.

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

At the time of notification, the licensee had exited all technical specification action statements.

CONFIRMED POSITIVE FITNESS FOR DUTY (FFD) TEST

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

"At 1311 EDT on October 13, 2025, it was determined that a non-licensed supervisor had a confirmed positive test as specified by the FFD testing program. The individual's authorization for site access has been terminated at all Duke Energy facilities.

"The NRC Resident Inspectors have been notified."

NOTIFICATION OF UNUSUAL EVENT

The following information was provided by the licensee via phone:

An Unusual Event was declared on October 13, 2025, at 1911 CDT under EAL HU1.1 due to notification of a credible security threat.

State and local agencies were notified. The NRC Resident Inspector was notified.

Notified DHS SWO, FEMA Operations Center, CISA Central Watch Officer, FEMA NWC, DHS Nuclear (email), CWMD Watch Desk (email)

* * * UPDATE ON 10/13/2025 AT 2315 EDT FROM VERONICA ROHAN TO ADAM KOZIOL * * *

The Unusual Event was terminated on October 13, 2025, at 2148 CDT.

Notified DHS SWO, FEMA Operations Center, CISA Central Watch Officer, FEMA NWC, DHS Nuclear (email), CWMD Watch Desk (email)