Event Notification Report for November 05, 2024

AGREEMENT STATE REPORT - LOST EXIT SIGNS

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

Four exit signs, each containing 12.57 curies of tritium (50.28 curies total), were determined to be lost by the licensee.

Manufacturer: Isolite Corporation
Model Number: SLX60

Colorado event number: CO240025

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 - STUCK OPEN SHUTTER

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

"[The licensee's] radiation safety officer (RSO) reported that a shutter had failed in the open position during a routine shutter check on October 9, 2024. This was a Ohmart/Vega [gauge containing] 15 mCi of Cs-137, serial number: 32153cp. The licensee barricaded the area around [the gauge]. A service repair request and leak test are currently in progress. The RSO stated that the licensee checked [radiation level] at 1 foot away, and found [exposure rate] to be 0.2 millirad per hour and presents no risk to health and safety."

NOTIFICATION OF RAPIDLY TERMINATED UNUSUAL EVENT DUE TO FIRE ALARM IN CONTAINMENT

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

"On 11/03/2024, at 2242 EST, DC Cook Unit 2 received an annunciator indicating a fire in containment. Verification time of existence of a fire exceeded the threshold for an Unusual Event (UE), and a UE was declared at 2312 on 11/03/24. Subsequently, the alarm was determined to not be valid and the UE was exited at 2328. Berrien County and the State of Michigan were notified of the UE declaration and exit.

"The NRC Resident Inspector has been notified."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

No actual fire existed. The emergency action level for this event is HU4.2.

Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

OFFSITE NOTIFICATION - INADVERTENT SIREN ACTUATION

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

"At 0500 CST, on November 4, 2024, the Monticello Nuclear Generating Plant was notified by Wright County dispatch of a spurious actuation of one emergency response siren that lasted approximately ten minutes. The cause of the actuation has not been determined and the vendor is investigating. The siren is no longer actuating. There was no impact to the health and safety of the public as a result of this event and the offsite response capabilities remain functional. No press release by the licensee is planned at this time. This event is being reported in accordance with 10 CFR 50.72(b)(2)(xi).

"The NRC Resident Inspector has been notified."