Event Notification Report for May 15, 2025

AGREEMENT STATE REPORT - MEDICAL EVENT

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

"Northwestern Memorial Healthcare contacted the Agency on 5/15/25 at 1525 CDT to advise of a potential reportable medical event. During the afternoon of 5/15/25, a patient was administered a therapeutic dosage of 200 mCi of Lu-177 (Lutathera) which resulted in a total delivered dose that differed from the prescribed dose by more than 20 percent. The event was reported within the required time by the licensee. A reactive inspection will be conducted next week. An update received today, 5/16/25, indicates that the patient is reporting no adverse effects. The licensee's investigation remains ongoing.

"Initial information indicates the intravenous administration of 200 mCi of Lu-177 (Lutathera) into the antecubital vein of the patient's right arm resulted in 142 mCi (less than 71 percent of the prescribed dosage) delivered to the target organ/tissue. The underdosing was confirmed after imaging the patient subsequent to the procedure on 5/15/25. The licensee is continuing their investigation and dose assessment. The patient and the referring physician were notified of the event as required."

Illinois item number: IL250021

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

The Agency communicated that this could be a possible extravasation, as some fraction of the administered activity was found in the patient's arm, but this has not been confirmed. The target organ was the pancreas.

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 - STUCK SHUTTER

The following information was received from the Maine Radiological Control Program (RCP) via phone and email:

"On May 15, 2025, at 1142 EDT, Nine Dragons (ND) Paper contacted the Maine RCP and reported that the source shutter on a fixed nuclear level gauge was stuck in the open position and that the shutter on another gauge was failing to lock.

"While doing routine shutdown activities to dismount a unit for pipe replacement, it was discovered that one of the fixed mounted source units (source serial number: 551-2-90, 30 mCi of Cs-137) was not able to rotate the shutter to the closed position due to the shaft spinning for the shutter mechanism. Based on this finding, the lock and tag out of the unit was stopped and all work that was planned for the pipe replacement was cancelled. There was not any exposure to any personnel and the systems are still secure in the normal operation mode. ND Paper personnel barricaded the source holder and pipe piece so there would be no unintentional work on the pipe the unit is mounted to. The pipe diameter is too small to allow personnel entry, eliminating exposure risks.

"Later, while doing checks on other sources in the area it was discovered that another source (source serial number: 986-3-90, 20 mCi of Cs-137) was not able to lock its shutter. The shutter closes, as verified with a survey meter, but the locking mechanism will not operate to secure the shutter in the closed position. After discussing the issues with Berthold (the original equipment manufacturer), and mill operations, ND Paper decided to order a set of replacement holders and sources from Berthold. ND Paper will leave the units in place until Berthold is able to get replacement units and is able to schedule technicians to replace the malfunctioning gauges."

Maine RCP Event Report ID Number: ME (2025-003)

AGREEMENT STATE - STUCK SOURCE

The following is a summary of information provided by the North Dakota Department of Environmental Quality (Department) via phone:

At 1315 CDT on May 15, 2025, the Department received a call from the radiation safety officer (RSO) of Iris NDT Inc. to report a stuck source in a SPEC-150 industrial radiography camera (serial number 2754). The 47.22 Ci Ir-192 sealed source became stuck when the operator attempted to withdraw it to the shielded position when the skid plate on the crank assembly buckled and became jammed. The RSO was able to successfully withdraw the source to the shielded position at 1344 CDT and the equipment was placed in an out of service status.

Initial reports indicate that no overexposure to employees or the public occurred, and an investigation is ongoing.

North Dakota Item Number: ND250001

FITNESS FOR DUTY

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

"At 0820 EDT on May 15, 2025, it was determined that a NextEra Energy Seabrook non-licensed supervisor failed a test specified by the Fitness For Duty testing program. The individual's unescorted access has been terminated. This event is being reported pursuant to 10 CFR 26.719(b)(2)(ii).

"The NRC Resident Inspector has been notified."

UNUSUAL EVENT - LOSS OF ALL OFFSITE POWER

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

At time 1828 EDT on 5/15/25, Oconee declared an Unusual Event (SU1.1) due to a loss of all offsite power for greater than 15 minutes. This occurred when the site lost their startup transformers (CT 2&3). At the time of the event, the site was restoring from switchyard maintenance and was experiencing a loss of their overhead powerline from the Keowee Hydropower Station. The underground powerline remains operable as a source of emergency power.

Units 1, 2, and 3 remain at 100 percent power with Unit 1 being unaffected by this event. Units 2 and 3 are being powered by their auxiliary transformers.

State and local agencies were notified. The NRC Resident Inspector has been notified.

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

* * * UPDATE ON 5/16/2025 AT 0052 EDT FROM ALAN HOGLEN TO SAMUEL COLVARD * * *

At time 0045, on 5/16/25, Oconee terminated their Unusual Event (SU1.1) due to restoring offsite power (CT 2&3 have been restored).

The NRC Senior Resident Inspector has been informed.

Notified R2DO (Desai), IR MOC (Grant), NRR EO (Felts).
External notifications: DHS SWO, FEMA Operations Center, CISA Central Watch Officer, FEMA NWC, DHS Nuclear SSA (email), CWMD Watch Desk (email).