Event Notification Report for December 19, 2025

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

LOST STATIC ELIMINATOR

The following is a summary of information provided by SABIC via email:

SABIC reported the loss of a Nuclecel ionizer air nozzle on lease from NRD, LLC containing 10 mCi of polonium-210.

The device was noticed to be missing on December 10, 2025, when preparing to send the device back to NRD. The last known use was in May 2025.

This device was used to clean static-sensitive printed circuit boards. SABIC assumes that an employee used it and did not return it or mistook it for a general use air nozzle and it is among their tools. SABIC has searched the building and interviewed employees who would have had access to the device in their secure facility.

SABIC is discontinuing the work requiring use of the device.

Model number: P02021-8001
S/N: A2NJ342
NRD lease: 083488

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

SHUTTER FAILURE

The following is a summary of information provided by the licensee via phone:

On November 4, 2025, at 1425 EST, the licensee radiation safety officer (RSO) was performing a tagout of the facility's kiln, which contains a 150 mCi Co-60 source in a Berthold model LB7444 device. When attempting to close the device shutter, the RSO observed no confirmation of the beam being broken and assumed the shutter was not turning. The shutter is normally open. Access to the kiln was restricted. There were no unexpected exposures. Replacement parts have been ordered, and the device will be serviced in the coming week.

AGREEMENT STATE REPORT - EQUIPMENT FAILURE

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

"On December 12, 2025, the Department was notified by the licensee radiation safety officer (RSO) that an event occurred on December 9, 2025, involving its Electra source irradiator. The RSO was not notified of the event until December 12, 2025. The event occurred when a patient was positioned for treatment. Approximately 1.5 seconds into the treatment an alarm occurred, and the irradiator automatically retracted the patient from the machine and closed the shutters on the device, shielding the sources. The technician entered the room and the dose rates appeared normal. Upon further inspection, the technician found one of the shutters had not closed. The technician closed the shutter manually. The RSO stated that after the patient was removed and the shutter manually closed the device was operated and functioned normally. The RSO stated the calculated dose to the patient was 0.7 rem. The patient was prescribed to receive a dose of 25 gray to the brain. The patient's physician was notified of the event and will notify the patient. The cause of the error has not been determined. A vendor has been contacted and will arrive to test the device on December 15, 2025. The RSO stated there will be no adverse effects to the patient from this event.

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

Texas incident number: 10245

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.