Event Notification Report for August 27, 2025

AGREEMENT STATE REPORT - STUCK OPEN GAUGE SHUTTER

The following information was provided by the Texas Department of State Health Services (the Department) via email:

"On August 28, 2025, the Department was notified that the shutter on a Vega SHF2C-45 nuclear gauge had failed in the open position during routine testing. The gauge contains a 500 mCi cesium-137 source. Open is the normal position for the shutter. The licensee reported there is no risk of additional radiation exposure to members of the general public or radiation workers, due to this on/off mechanism failure. Additional information will be provided as it is received in accordance with SA-300."

Texas incident number: 10219
NMED number: TX250039

CONCURRENT REPORT FOR OFFSITE NOTIFICATION

The following is a summary of information provided by the licensee via phone and email:

Centrus American Centrifuge Operating (ACO) received notification from a Fluor-BWXT Portsmouth (FBP) environmental technician supervisor that the chlorine level at outfall '013' was at 0.063 mg/L. This exceeds the National Pollutant Discharge Elimination System permit limit on total chlorine at outfall '013' of 0.05 mg/L. Centrus ACO notified the Ohio Environmental Protection Agency at 1450 EDT.

Elevated chlorine levels at outfall '013' were initially noted and reported on August 18, 2025, under EN 57874. Centrus ACO has since determined that a sanitary line break that went into a holding pond is the cause of the elevated chlorine levels. Elevated chlorine levels observed today are attributed to residual chlorine upstream of the outfall.

This report is in accordance with condition notification #12816.

The NRC regional office was notified.

AGREEMENT STATE REPORT - LOST SOURCES

The following information was provided by the Illinois Emergency Management Agency (the Agency) via phone and email:

"As a result of an ongoing Agency investigation into unresponsive general licensees, the Agency became aware that two (2) generally licensed gas chromatography devices containing 15 millicuries of Ni-63 are missing.
"Reportedly, on or about February 2023, Morton Grove Pharmaceuticals (Morton Grove, IL) ceased operations and improperly auctioned the two generally licensed devices, along with all other assets.
"The licensee failed to properly transfer or dispose of the devices, two Agilent Technologies model G23974 (s/n U10800 and s/n U12506). Agency inspectors conducted a site investigation on August 27, 2025, and confirmed no lab equipment is on site.
"The quantity of radioactive material involved, while unlikely to be dangerous to the public, is reportable within 30 days to the Agency and the U.S. NRC. Efforts to identify the buyers of the devices through the auction company have been unproductive and, absent additional information, the investigation is closed."

Illinois item number: IL250035

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

PART 21 - POWER DRIVEN POTENTIOMETER WITH LOOSE RELAY SOCKETS

The following is a summary of information provided by Engine Systems Inc. (ESI) via email:

Relay sockets used to retain relays 'K1' and 'K2' on a power driven potentiometer (PDP), part number: ESI 50258, were found to have low retention force. Without both relays installed, the raise and lower function of the PDP is inoperable, thus preventing adjustment of the generator output voltage.

There is a scenario where if the PDP is adjusted to a value other than the normal voltage setpoint and if the K1 or K2 relays were to dislodge during a subsequent emergency event, the PDP would not return to its preposition setpoint and therefore the generator terminal voltage would not return to its desired voltage setpoint, in which case the ability of the emergency diesel generator to carry its safety-related loads could be impacted


Affected Plants
Region 3: Prairie Island

ESI contact information:

Dan Roberts
Quality Manager
Engine Systems Inc
175 Freight Rd 175
Rocky Mount, NC 27804