Event Notification Report for November 06, 2024

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."

AGREEMENT STATE - DAMAGED S-TUBE

The following information was provided by the New York State Department of Health via email:

"New York State Department of Health (NYSDOH) Bureau of Environmental Radiation Protection conducted a routine inspection of Sky Testing Services, Inc. (Radioactive Materials License No. C5409) and discovered that a Delta 880 Camera (serial number D6138) had been taken out of service due to a worn s-tube. The camera had been sent to QSA for resourcing on July 25, 2024. As part of the routine servicing/resourcing the leak test for the Ir-192 and depleted uranium (DU) were below 0.001 microcurie, thereby indicating that the source was not leaking. QSA performed a borescopic exam to discover that the s-tube was worn out and the DU shield was exposed. As a result, the camera had been removed from service in accordance with 10 Code of Federal Regulations (CFR) 34.27. This appears to meet the reportability criteria in 10 CFR 30.50(b)(2) and (c), in addition to 34.101 (equivalent to 12 [New York Codes, Rules and Regulations (NYCRR)] 38.34(h)(3)). Even though the DU was not found to be leaking, the s-tube was worn and retained by the manufacturer during routine quality checks/resourcing.

"Prior to discovery of this worn s-tube, the device appears to have operated as intended but posed vulnerability to potential failure from what is believed to be routine wear and tear. As a result, no unplanned exposures directly resulted from this worn s-tube prior to its discovery during routine servicing.

"NYSDOH did request corrective actions from this event to confirm if this s-tube will be replaced or if the camera will be removed from service indefinitely. Additionally, NYSDOH informed the facility of the reporting criteria required to address in these corrective actions. It does not appear that the licensee was aware of the reporting requirement.

"It is unclear if this event truly meets the reportability under 10 CFR 30.50, however, NYSDOH wants to report this as a precautionary measure.

"NYSDOH is closely monitoring this event and has assigned NYSDOH Incident No. 1505. More information will be provided to Nuclear Material Events Database (NMED) once available."

OFFSITE NOTIFICATION

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

At 1118 EST, on 11/6/24, a small brush fire occurred within the owner controlled area. The fire started when a lawn mower passed by a pile of dry leaves that had built up for a couple of weeks. Security contacted Windham County emergency dispatcher for fire department support. Vermont Yankee personnel managed to put the fire out prior to the fire department arriving onsite. Due to the offsite notification to local law enforcement and fire department, Vermont Yankee is reporting this event under 10 CFR 50.72(b)(2)(xi) and 10 CFR 72.75(b)(2).

Vermont Yankee will also notify the State of Vermont and NRC Region 1.