Event Notification Report for August 01, 2025

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 SCRAM

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

"On 8/1/2025, at 2350 CDT, Browns Ferry Unit 1 experienced an automatic scram due to low reactor water level. A low reactor water level of `+2' inches resulted in a valid actuation of the reactor protection system which caused all of the rods to insert. During the scram response, there was a valid actuation of the primary containment isolations systems groups 2, 3, 6 and 8. Upon receipt of these signals, all components actuated as required. Following the scram, reactor water level lowered below the '-45' inches setpoint, actuating high pressure coolant injection and reactor core isolation coolant and tripped both reactor recirculation pumps as required. Operations responded and stabilized the plant. Reactor water level is being maintained via the condensate system. Decay heat is being removed by bypass valves to the main condenser. There was no impact on Units 2 and 3.

"This event requires a 4-hour non-emergency report per 10 CFR 50.72(b)(2)(iv)(B), any event or condition that results in actuation of the reactor protection system when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.

"This event requires a 4-hour non-emergency report per 10 CFR 50.72(b)(2)(iv)(A), any event that results or should have resulted in emergency core cooling system (ECCS) discharge into the reactor coolant system as a result of a valid signal except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.

"This event requires an 8-hour non-emergency report per 10 CFR 50.72(b)(3)(iv)(A), any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B): 1) Reactor protection system including: reactor scram or reactor trip. 2) General containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs).

"All safety systems operated as expected. At no time were public health and safety at risk. The NRC Resident Inspector has been notified."

EN Revision Imported Date: 9/29/2025

EN Revision Text: AGREEMENT STATE REPORT - LOST EXIT SIGNS

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

The Department received a notification from the licensee that eight (8) exit signs, containing a total of 65.65 Ci of tritium were lost in Denver, Colorado.

Manufacturer: SRB Technologies & Isolite Corporation
Model Number: BXU10GS (1 sign), BR-10-BK (2 signs), BRU10S (2 signs), BETALUX (3 signs).

Activities:
Models - BXU10GS & BR-10-BK: 9.21 Ci each
Model - BRU10S: 7.76 Ci each
Model - BETALUX: 7.5 Ci each

Event Report ID No.: CO250026


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