Event Notification Report for August 04, 2026

AGREEMENT STATE REPORT - LOST EXIT SIGN

The following is a summary of information provided by the Colorado Department of Public Health and Environment via email:

The licensee reported that one exit sign, containing 9.21 Ci of tritium, was lost in Westminster, Colorado.

Manufacturer: SRB Technologies
Model number: BX-10-GY

Colorado event number: CO260014

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

AGREEMENT STATE REPORT - LOST EXIT SIGNS

The following is a summary of information provided by the Colorado Department of Public Health and Environment via email:

Two exit signs were declared lost by the licensee on December 19, 2024. The exit signs are model number BR-20-BK manufactured by SRB Technologies and have an H3 (tritium) source of 17.51 Ci each.

Colorado Event Number: CO260015

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

AGREEMENT STATE REPORT - MEDICAL EVENT

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

"The Program was notified on July 28, 2026, that a reportable medial event had occurred on July 24, 2026, at the Loma Linda University Medical Center. The authorized user had prescribed Y-90 Theraspheres, distributed by Boston Scientific Corp. and produced by BWXT Medical Ltd. with a dose to the target (segment 8 of liver) of 570 Gy. The delivery of the dose to the patient seemed to be uneventful. Initial radiation surveys of the patient, the operating room, and the waste container were reported as within normal limits. Nuclear medicine initially reported that 98 percent of the dose was delivered to the patient.

"However, the patient's post-treatment single-photon emission computed tomography (SPECT) imaging indicated very low activity was found in the patient's liver. A review of the nuclear medicine processes determined that the waste container with the microcatheter was actually radioactive. The initial measurements recorded by the certified nuclear medicine technologist were erroneously recorded as microrem per hour instead of millirem per hour. A second SPECT image was taken of the patient and calculations indicated that 7 percent of the dose was received by the patient, which qualifies as a medical event under 10 CFR 35. 3045. A Boston Scientific representative was present during the administration. He has arranged for the delivery system to be evaluated by the manufacturer once the radiation levels are decayed. The Program will follow-up with the licensee during this investigation."

California 5010 Event Number: 072426

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.

MANUAL REACTOR TRIP

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

"On August 3, 2026, at 1420 EDT, with Millstone Unit 2 operating in Mode 1 at approximately 100 percent power, operators manually tripped the reactor following an 'A' steam generator feedwater pump trip. The reactor trip was uncomplicated, and all plant systems responded as expected. Operations responded and stabilized the plant. The auxiliary feedwater system automatically actuated as designed following the reactor trip and provided feedwater to the steam generators. Decay heat removal is being maintained by the main steam system.

"This event is reported pursuant to 10 CFR 50. 72(b)(2)(iv)(B) as a four-hour, non-emergency notification due to the actuation of the reactor protection system while the reactor was critical.

"There was no impact on Unit 3. No radiological releases occurred as a result of this event, and there was no impact on the health and safety of the public or station personnel.

"The NRC Resident Inspector has been notified. "