Event Notification Report for August 11, 2025

EN Revision Imported Date: 8/11/2025

EN Revision Text: AGREEMENT STATE REPORT - MEDICAL EVENT

The following report was provided by the Georgia Radioactive Materials Program via email:

"The licensee called and stated that during a post treatment review with the physician conducted today, it was identified that a patient receiving yttrium-90 therapy on July 7, 2025, was underexposed due to a kink in the catheter. The prescribed dose was 0.439 GBq (11.853 mCi), but the administered dose was determined to be 0.177 GBq (4.779 mCi). This represents a 40.32 percent deviation from the prescribed dose, which exceeds the 20 percent reporting threshold. Upon further review of the patient's treatment history, it was additionally discovered that two prior underdosing events occurred on August 20, 2024, and September 30, 2024. Both events were also attributed to catheter kinking and involved dose delivery to small treatment volumes in limited target areas. [The licensee] stated that a formal written report detailing all three underdosing events, along with supporting documentation, will be submitted via email on Monday, August 4, 2025."

* * * UPDATE ON 8/8/2025 AT 1047 EDT FROM ANASTASIA BENNETT TO TENISHA MEADOWS * * *

The following is a summary of information provided by the Georgia Radioactive Materials Program via email:

The licensee provided three updated official incident reports, including two prior underdosing events that occurred on August 20, 2024, and September 30, 2024.

The July 7, 2025, incomplete Y-90 dose delivery was attributed to clumping of the microspheres within the microcatheter. As part of corrective actions, the specific type of microcatheter involved in this incident has been discontinued for use in Y-90 procedures.

During the administration of Y-90 microspheres on August 20, 2024, the prescribed dose was 0.224 GBq (6.0 mCi) and the administered dose was 0.150 GBq (4.1 mCi).

During the Y-90 treatment performed on September 30, 2024, the prescribed dose was 0.290 GBq (7.83 mCi) and the administered dose was 0.166 GBq (4.5 mCi).

Both the August 20, 2024, and September 30, 2024, underdosing events were attributed to anatomical limitations. Specifically, a small treatment volume and narrow treatment vessels, which restricted adequate flow of microspheres. As part of the corrective actions taken, it was determined that more than 30 psi of pressure is required to deliver microspheres into small vessels. Therefore, future cases involving small treatment vessels will consider the use of delivery systems capable of generating higher pressure to ensure effective dose administration.

Notified R1DO (Henrion) and NMSS Events Notification (email)

Georgia Incident Number: 105

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 - DAMAGED GAUGE

The following information was provided by the California Radiation Control Program via email:

"[The licensee] contacted the California Department of Emergency Services to report a moisture density gauge was run over at a worksite. The gauge was a CPN MC-3, S/N M30019316 (10 mCi cesium-137, 50mCi americium-241/beryllium). After placing the gauge with the cesium-137 source in the locked and shielded position on the ground, the operator went to retrieve some equipment from his vehicle when the bulldozer ran over the gauge snapping the source rod off and damaging the plastic housing on the top of the gauge. The bottom of the gauge was intact, and the americium-241/beryllium source was still attached and undamaged. The licensee was instructed to place the gauge in the transport case and wait until the Riverside County Department of Environmental Health inspector arrived at the scene.

"Upon arrival, the inspector performed a radiation survey (model and serial number not reported) and found there were no significant radiation levels above background. The gauge will be transported to Maurer Technical Services for disposal. The investigation into the incident by the California Department of Public Health is ongoing."

California 5010 Number: 080125

AGREEMENT STATE REPORT - STUCK SHUTTER

The following report was received from the North Carolina Division of Radiation Protection via email:

"[The] licensee reports that while they were performing routine shutter tests, the handle to a fixed nuclear gauge broke, leaving the gauge in the stuck open position. Operational doses are considered low and the area has been cordoned off to any unauthorized access. The licensee is currently arranging with the gauge manufacturer for assistance on repair."

Device: Fixed Nuclear Gauge
Manufacturer: Ohmart Vega
Model: SH-F1B
S/N: 6133CN

Source: cesium-137
Manufacturer: TBD
S/N: TBD
Activity: 66.2 mCi

North Carolina Event Number: TBD

AUTOMATIC REACTOR TRIP

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

"At 1113 EDT on August 9, 2025, with Unit 3 in mode 1 at 100 percent power, the reactor automatically tripped due to a turbine control system failure. The trip was uncomplicated with all systems responding normally post-trip. Operations stabilized the plant in mode 3. Decay heat is being removed by steam generators. Unit 4 is not affected. This event is being reported pursuant to 10CFR50.72(b)(2)(iv)(B).

"An actuation of the auxiliary feed water system (AFW) occurred during the Unit 3 reactor trip. The AFW system automatically started as designed. This event is being reported pursuant to 10CFR50.72(b)(3)(iv)(A).

"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 cause of the turbine control system failure is under investigation.