Event Notification Report for December 18, 2025

EN Revision Imported Date: 12/18/2025<br><br>EN Revision Text: AGREEMENT STATE REPORT - POTENTIAL OVEREXPOSURE

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

During a routine inspection on October 21, 2025, the Department was made aware that on two separate occasions, the production manager had performed repairs on the production line of F-18 fluorodeoxyglucose (FDG) without wearing dosimetry.

On Tuesday, October 28, 2025, inspectors from the Department were following up on the concerns and confirmed that on one occasion, the production manager was not wearing dosimetry during the replacement of tubing on a cracked line inside a production hot cell. This repair was conducted along a 25.4 cm (10 inches) tubing line with one end being 10 cm (3.9 inches) from the source vial of F-18. The activity of the source was 118.4 GBq (3.2 Ci) as per the radiation safety officer (RSO). Re-enactment of the procedure was produced with the production manager to reconstruct similar parameters. The RSO initially was not made aware of the individual not wearing dosimetry. Dose estimation is currently being conducted by the RSO and by the Department. The licensee will also have an independent contractor perform a dose calculation for the event that was conducted without dosimetry.

While dose estimations are being calculated, the Department believes it has enough information to determine that this event threatens to cause an extremity exposure greater than or equal to 250 rads, and thus, are reporting immediately to the NRC in accordance with SA-300. This investigation is ongoing and updates will be provided.

Arkansas Event Number: ARK-2025-014

* * * UPDATE ON 11/10/25 AT 1357 EST FROM HUNTER BROADWAY TO KAREN COTTON * * *

The following information was provided by the Arkansas Department of Health (the Department) via email:

"A written report has been provided to the Department on November 4th, 2025, from the radiation safety officer (RSO) of the licensee regarding the investigated incidents. The Department is performing dose calculations to compare using measurements and information gathered from the investigation. The Department's time-motion study of the unbadged repair procedure by the product manager has reduced the time of exposure significantly. Due to the shortening of time, this incident is more than likely not going to exceed the reporting threshold of an extremity exposure greater than or equal to 250 rads. The Department will continue to provide updates and comparison of dose estimation.

"Important of note, there is a third incident mentioned by the RSO that occurred involving the same product manager that is referenced as the 'resin pack event'. This event occurred on October 23, between our routine inspection on October 21, 2025, and our investigation which occurred on October 28, 2025. This event was not a part of the allegation but was discussed in detail during the investigation.

"The written report was submitted from Arkansas Licensee, ARK-1008-03124 and this report will be submitted to the NMED database."

Notified R4DO (Vossmar), NMSS Events Notifications (email).

* * * RETRACTION ON 12/17/2025 AT 0840 EST FROM HUNTER BROADAWAY TO JORDAN WINGATE * * *

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

"Dose calculations have been performed by the RSO of the facility and the Department.

"For dose calculations, even with simplification of geometry by using a point source estimate, the largest estimate calculated was 7.1 rads. The section chief requested consideration of the geometry of the source vial along with tubing and spill, which better fits the modeling of the exposure. This brought the calculations to around 2.7 rads. The RSO estimates a dose of approximately 1 rad. Our estimates compared to the RSO of 3DI's estimate were comparable and do not exceed the dosage reporting requirement of an extremity of 250 rads. The Department has determined that this event is not reportable to the NRC. The written report is still on the stage of corrective actions and is undergoing conversations between the RSO and the department. The Department's intention to submit the final investigation report to the NRC regardless, as it has drawn attention."

Notified R4DO (Agrawal), NMSS Events Notifications (email).

AGREEMENT STATE REPORT - LOST SOURCES

The following information was provided by the PA Bureau of Radiation Protection (Department) via email:

"On December 10, 2025, the Department was notified that the licensee may have lost two 100-millicurie americium-241 sealed sources (S/Ns 110790 and 113504). It is thought the loss occurred between June 2 and June 20, 2025, during clean-up activities in a maintenance area where the two sources may have been inadvertently disposed of in a roll-off container. The sources were used in Filtec model FT-50 fill gauges. The most recent leak test for the sources was completed, and passed, on June 1, 2025.

"The Department is in contact with the licensee, awaiting more information regarding any possible overexposures or contamination, and will update this document as more information is provided.

"The Department will perform a reactive inspection."

PA Event Report ID: PA250017

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 - MISSING SOURCE

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

"On December 11, 2025, at 1008 CST, the Department received a telephone notification that the licensee's x-ray fluorescence analyzer is missing. [The licensee has] exhausted all options for searching possible storage locations. The device was likely disposed of via ordinary trash. There are no known exposures to the public and no known contamination resulting from the incident."

Model: Niton XLp 303A
Source: 5 mCi Cd-109
S/N: 8567

WI event number: WI250019

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

INVALID SPECIFIED SYSTEM ACTUATION

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

"This 60-day optional telephone notification is being made in lieu of a licensee event report submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).

"At approximately 1001 EDT on October 21, 2025, an invalid actuation of the 'B' train motor-driven auxiliary feedwater (MDAFW) pump occurred with Harris Nuclear Plant while in mode 6. After investigation [it was determined that] the pump automatic start signal was from the anticipated transient without scram mitigation system actuation circuitry (AMSAC). Restoration from functional testing of AMSAC was in progress at the time of the pump start. Separate surveillance testing of the 'B' train emergency safeguards sequencer was being prepared for and enabled the 'B' train MDAFW pump start while restoring 'B' MDAFW pump control power prior to the event. The 'B' train MDAFW pump started and ran with no abnormalities noted. The overlapping testing activities allowed for the AMSAC start signal to be sent to the 'B' MDAFW pump.

"The actuation was not initiated in response to actual plant conditions, it was not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation.

"This event did not impact the health and safety of the public. The NRC Resident Inspector has been notified."

FITNESS FOR DUTY EVENT

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

"On December 15, 2025, at approximately 1131 EST, a manager violated the FFD policy, which is reportable under 10 CFR 26.719(b)(2)(ii). Site access personnel detected the odor of alcohol during in-processing activities. For-cause testing was performed, and the test confirmed the individual was positive for alcohol. The individual was denied access.

"The NRC Resident Inspector has been notified."

FITNESS FOR DUTY (FFD) EVENT

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

"On December 16, 2025, at 1000 CST, it was determined that a supervisor tested positive in accordance with the FFD testing program. The individual's authorization for site access has been terminated.

"The NRC Resident Inspector has been notified."

PART 21 - EMERGENCY DIESEL GENERATOR FAILURE

The following information was provided by the licensee via email:

"This is a non-emergency notification required by 10 CFR 21.21(d)(3)(i).

"A written report in accordance with 10 CFR 21.21(d)(3)(ii) will be provided within 30 days.

"On December 16, 2025, Peach Bottom engineering staff determined that a defect identified during a causal evaluation could constitute a substantial safety hazard. Failure analysis testing of a Fairbanks Morse Defense, emergency diesel generator (EDG) engine cylinder liner documented gross delamination between layers of the cylinder liner chrome plating. The delamination and subsequent loss of chrome plating contributed to piston ring damage that enabled combustion gas leakage into the engine crankcase, tripping the EDG on high crankcase pressure. The Fairbanks Morse Defense part number: LINER, CYLINDER, KIT, F/DIESEL GEN, MOD-38TD8-1/8, is purchased as a safety related part. Peach Bottom's procurement specification requires one single layer of chrome plating which is inconsistent with the defect exhibited, 'at least two passes of chrome plating' during failure analysis. The EDG piston ring failure and ensuing inoperability resulted in the loss of a sub-component function, which could constitute a substantial safety hazard. The defect extent of condition potentially includes 5-cylinder liners with serial numbers: H837-1, H837-2, H832-2, H838-1, and H9311-2.

"On December 17, 2025, the Peach Bottom site Vice President was notified of the requirement to report this event under 10 CFR 21.21."

The NRC Senior Resident Inspector at Peach Bottom has been notified

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
This condition effects safety related diesel generators "E-1" and "E-3". After repair of "E-1" and an operability determination on "E-3", no limiting conditions of operability were entered as a result of the defect. Limerick Generating Station is potentially affected by this defect. Fairbanks Morse Defense has also been notified.