Event Notification Report for October 13, 2026

AGREEMENT STATE REPORT - DAMAGED GAUGE

The following information was provided by the Virginia Office of Radiological Health, Radioactive Materials Program (VRMP) via email:

"On October 2, 2026, at approximately 1600 EDT, the Virginia Office of Radiological Health was notified of an incident involving damage to a portable nuclear gauge. At approximately 1600 EDT on October 1, 2026, an InstroTek, Inc. model 3500 portable nuclear density/moisture gauge, (S/N 1999), containing 7.58 mCi of Cs-137 (S/N CZ6179) and 39.2 mCi of Am-241 (S/N 416/14), was struck by a roller on a soil compaction project in Harrisonburg, VA. The authorized user notified the radiation safety officer (RSO) who went to the site to evaluate the gauge's condition. The RSO contacted the Virginia Office of Radiological Health by phone within 24 hours.

"Per the RSO, the gauge was run over by a compaction roller. The source rod was not extended when the gauge was struck. The cesium source remained in the fully shielded position, and the Am/Be source block remained intact. The area was cordoned off at roughly 20 feet around the damaged gauge. [Results of] surveys taken by the RSO [are as follows]: background 0.02 mR/h, contact 8.0 mR/h, at 4 feet 0.20 mR/h; at 10 feet 0.04 mR/hr. The gauge was secured in its transportation case and returned to licensee's storage to be leak tested before shipment for evaluation. There were no apparent exposures as a result of this incident.

"The agency will conduct a formal investigation."

Virginia event report number: VA260005

MEDICAL EVENT

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

"On October 5, 2026, a patient undergoing Y-90 Therasphere radioembolization of the right medial tissue of the liver was underdosed by approximately 50 percent.

"The physician authorized user completed the administration as normal with no unusual circumstances noted at 1114 EDT. At 1317, during post-treatment measurements, the health physicist determined that only 52.5 percent of the Y-90 microsphere had been administered.

"The prescribed activity was 10.4 mCi, while the administered activity was 5.4 mCi.

"This was the third Y-90 administration in a series of four administrations to four separate target liver tissues.

"The other three administrations were completed as normal and within 20 percent of the prescribed activity.

"It is believed that the unadministered activity remained trapped in the catheter.

"The patient received approximately 620 Gy to the target tissue, which is clinically adequate. The patient will not need to be retreated."

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 - SHUTTER MALFUNCTION

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

"On October 6, 2026, the Department was contacted by a representative of the licensee to report a radiation event that had been identified at 1305 CDT. The licensee was performing routine work utilizing a fixed gauge device when the device operator received an alert from the control panel that a shutter had unexpectedly opened when it should have remained closed. The radiation safety officer was immediately notified. The shutter was able to be closed from the user console and was cycled a few times to ensure functionality.

"The device is a Mahlo model 11-011988. It contains an Eckert and Ziegler Pm-147 KAC.D3 source, S/N AH-4867. It has an assay of 1000 mCi as of April 15, 2016. It currently contains approximately 62 mCi.

"No employees were exposed to any elevated radiation levels. The manufacturer was notified and is currently coordinating with the licensee to get a service engineer on site. The Department will continue to follow-up with the licensee."

Wisconsin event report identification number: WI260017

AUTOMATIC REACTOR TRIP

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

"At 1614 EDT, on 10/10/2026, with Unit 1 in mode 1 at 100 percent power, the reactor automatically tripped. The reactor protection system (RPS) actuated while critical, safety relief valves actuated, and a group 2 primary containment isolation occurred. The trip was not complex with all systems responding as designed. The cause of the trip is under investigation.

"Operations responded and stabilized the plant in mode 3. Reactor water level is being maintained by the feedwater system. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves. Unit 2 is not affected.

"Due to the RPS actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B).

"There was no impact to 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:

The reactor trip occurred following an electrical transient which caused a turbine generator trip.

FITNESS FOR DUTY

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

"On October 12, 2026, at 0724 CDT, Waterford Steam Electric Station Unit 3 was notified an Entergy supervisor had a confirmed positive test for alcohol during a for-cause fitness-for-duty test. The individual's access has been terminated.

"The fitness-for-duty policy violation is being reported under 10 CFR 26.719(b)(2)(ii).

"The NRC Senior Resident Inspector has been notified."