Event Notification Report for May 22, 2025

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

AGREEMENT STATE REPORT - STOLEN GAUGE

The following information was provided by the California Department of Public Health via email:

"On May 15, 2025, the radiation safety officer (RSO) of Alta California Geotechnical, Inc. (Alta), contacted the Brea office of the California Department of Public Health to report a stolen moisture density gauge. The gauge was a CPN model MC-3 S/N MD30907144 (10 mCi, Cs-137; 50 mCi, Am:Be-241). The gauge operator discovered the gauge was missing on May 14, 2025, at approximately 1500 PDT, before they left the jobsite in Murrieta, CA. The operator noticed that the tailgate on the truck was down, the gauge case was open, and the gauge was missing. Alta personnel searched the surrounding area without locating the gauge and contacted the Murrieta Police Department to report the theft. A second search was performed the following morning with no success locating the gauge. The event was reported to the California Department of Public Health. The RSO confirmed that a trigger lock, securing the Cs-137 source in the shielded position on the gauge, was in place. The licensee's investigation into this event is ongoing and will be reviewed further by the California Department of Public Health."

California 5010 Number: 051525

* * * UPDATE ON 05/16/25 AT 1934 EDT FROM DONALD OESTERLE TO KERBY SCALES * * *

The following update was received from the California Department of Public Health via email:

"On May 16, 2025, the gauge was found and recovered. The gauge will be sent to the service provider to be evaluated."

Notified R4DO (Gepford), NMSS_Events_Notification, ILTAB, and CNSNS Mexico via email.

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

TECHNICAL SPECIFICATION REQUIRED SHUTDOWN

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

"On May 21, 2025, at 0656 CDT, River Bend Station (RBS) was operating at 100 percent reactor power when a plant shut down was initiated due to technical specification (TS) requirements. At 0324 on May 21, 2025, unidentified drywell leakage exceeded a 2 gallon per minute change over a 24-hour period. TS limiting condition of operation 3.4.5 condition 'C' was entered with a required action to verify the source of the unidentified leakage increase is not from service sensitive type 304, type 316 austenitic stainless steel, or other inter-granular stress corrosion cracking susceptible material within 4 hours. This required action could not be completed within the completion time.

"This event is being reported under 10 CFR 50.72(b)(2)(i) as an event or condition that results in a TS required plant shut down.

"The NRC Resident has been notified."