Event Notification Report for July 16, 2025

AGREEMENT STATE REPORT - LOSS OF CONTROL OF RADIOACTIVE MATERIAL

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

"The BRC received notification from Cardinal Health that a courier, employed by a courier company, was involved in a traffic stop resulting in an arrest. The courier was transporting a radioactive materials package containing one 5 mCi I-131 source at the time of the arrest. The transporting vehicle was then held at a towing company storage, with the towing company stating an intent to retain all impounded material until proper permissions could be received from the vehicle owner. The towing company was informed that they must release the material to Cardinal Health and have agreed to comply."

Florida Incident Number: FL25-069

AGREEMENT STATE REPORT - STUCK SHUTTER

The following is a summary of information received from the Alabama Office of Radiation Control (the Agency) via email:

"On July 16, 2025, at 0914 CDT the Agency received a call from the radiation safety officer (RSO) for INEOS Styrolution American, LLC. stating that during regular shutter checks, the shutter for the Ronan Model SA1-F37 Serial No. 8171GK, with 5000 millicuries cesium-137 would not close. The facility contacted RSO Services to schedule repair of the device. The facility has a maintenance outage scheduled in September of this year.

"The Agency will provide more information as the investigation continues."

Alabama Incident Number: 2025 25-02

EN Revision Imported Date: 9/15/2025

EN Revision Text: AGREEMENT STATE REPORT - EQUIPMENT FAILURE

The following report was received by the Illinois Emergency Management Agency (the Agency) via phone and email:

"The Agency was contacted this afternoon (7/17/25) by Isomedix Operations, Inc. in Libertyville, IL to advise of a reportable equipment failure.

"According to the report, the radiation monitor used to perform required radioactivity measurements of the pool water (e.g., leak testing of the pool irradiator sources) failed at some point in the last month. It was discovered yesterday, 7/16/25, during a routine monthly check when the system failed to alarm when tested with a check source.

"Replacement monitoring equipment was installed, and the pool water was determined to be free of radioactivity. This incident had no impact to public or worker safety, nor is there any indication of leaking sources. However, the reportable criteria in 32 Illinois Administrative Code 340.122(c)(2) appear to have been met. The licensee met the 24-hour reporting requirement, and the Agency will report the matter to the NRC shortly.

"Inspectors will conduct a reactive inspection to determine root cause and corrective action."

Illinois Item Number: IL250028

* * * UPDATE ON 09/12/2025 AT 1142 FROM KIM STICE TO ROBERT THOMPSON * * *

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

"On 7/17/25, the Agency conducted a reactive inspection via phone with the [Isomedix] corporate radiation safety office and confirmed that identical functioning monitoring equipment was installed immediately after the failure was identified, and that the faulty instrument was to be sent to the manufacturer for examination and to determine a possible failure cause. Additionally, the corporate radiation safety officer reviewed additional tests conducted on 7/16/25 (surveys of the deionization tanks conducted and pool water sample collected and analyzed for radioactive contamination) to confirm no leaking of sources, all with negative results.

"On 8/20/25, inspectors followed up during a routine inspection and confirmed that replacement monitoring equipment had been installed and was calibrated and functional. The licensee advised that they were still waiting on a report from the manufacturer to determine if any additional corrective measures would be instituted. The licensee stated that any information received would be shared with the Agency. Regardless, the Agency will follow up at the time of next inspection."

Notified R3DO (Santiago) (email), NMSS Events Notification (email).

AUTOMATIC REACTOR TRIP

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

"At 0959 CDT on 7/16/2025, with Unit 1 in mode 1 at 100 percent power, the reactor tripped coincident with operation of a bus 11 knife switch during performance of [surveillance procedure] SP 1857, 4KV bus 11/12 undervoltage and underfrequency relay test. The trip was not complicated with all systems responding normally post trip.

"Operators responded and stabilized the plant. Decay heat is being removed by discharging steam using the steam dump system and the main feedwater system. Unit 2 is not affected.

"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). The expected actuation of the auxiliary feed water system (an engineered safety feature) is being reported as an eight-hour report under 10 CFR 50.72 (b)(3)(iv)(A).

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