Event Notification Report for July 15, 2025

AGREEMENT STATE REPORT - STOLEN MOISTURE DENSITY GAUGE

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

"On July 7, 2025, at about 0710 CDT, a report was made by the licensee that an Istrotek model 3500 moisture density gauge containing a 10 mCi Cs-137 source and a 40 mCi Am241/Be source had been discovered stolen at 0518 CDT on July 7, 2025, from the bed of a pickup truck at the residence of an employee in Fort Worth, Texas. The securing chains and locks had been breached overnight and the gauge taken.

"The gauge handle was secured by a lock; no immediate public health issue is anticipated.

"A report was made to the Fort Worth Police Department."

Texas incident number: 10208

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 REPORT - STUCK OPEN SHUTTERS

The following information was provided by the South Carolina Department of Environmental Services (the Department) via phone and email:

"The licensee informed the Department via email on July 3, 2025, (a phone notification was not made to the Department), that two fixed gauging devices were disabled or failed to function as designed. The licensee reported that a 2 curie cesium-137 Kay-Ray/Sensall Inc. model number: 7700Y-1000, serial number: S95K1307 was stuck in the open position (exposed), and a 100 millicurie Cs-137 Texas Nuclear model number: 570-571157C, serial number: B2988 is stuck in a partially open position (exposed). Both of the devices are attached to a process vessel.

"The licensee also informed the Department that a 100 millicurie Cs-137 Texas Nuclear model number: 570-571157C, serial number: B2987 has a visible crack in the source housing and is attached to a process vessel.

"The licensee performed ambient dose rate surveys and reported results similar to the Sealed Source and Device Registry (SSDR) certificates.

"The licensee did not report any overexposures or ongoing health/safety concerns.

"This event is still under investigation by the Department."

South Carolina Event Number: TBD

AGREEMENT STATE REPORT - STUCK OPEN SHUTTER

The following information was received from the Minnesota Department of Health (MDH), Radioactive Materials Unit via email:

"On Monday, July 7, 2025, at 1000 [CDT], the licensee discovered a gauge with a stuck shutter. The gauge is a Texas Nuclear fixed gauge with a 200 mCi Cs-137 source. Maintenance was planned on the apron feeder near the gauge. The maintenance group requested the electrical group close the shutter on this gauge. The electrical crew was unable to close the shutter after multiple attempts and decided to remove the gauge and place it in a container containing lead plates. The radiation safety officer (RSO) took readings 1 foot from the top and sides of the container. The highest reading was 0.3 mR/hr. The container was labeled as radioactive material and taped off with red tape. The RSO reached out to QAL-TEK to dispose of the unit. QAL-TEK stated they may be able to come out in less than two weeks."

Minnesota Event Report ID: MN250004

LOST GENERALLY LICENSED SOURCE

The following information was provided by the licensee via phone:

During a recent license renewal inquiry, it was discovered that during the decommissioning of the licensee's deepwater flow line in August 2017 a jumper with a generally licensed meter containing a nuclear source was removed and inadvertently scrapped. This event is under investigation by the licensee.

Roxar Flowmeter
Model number: RFM-SH7950
Source: Cs-137, 30 mCi
General License Number: 725736-16

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

AUTOMATIC REACTOR TRIP

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

"At 1418 EDT on 7/13/2025, with Unit 2 in mode 1 at 100 percent power, the reactor automatically tripped due to a main turbine trip. The trip was not complicated with all systems responding normally post trip.

"Operators responded and stabilized the plant. Decay heat is being removed by discharging steam to the main condenser using the steam dump system and the auxiliary feedwater (AFW) system. Unit 1 is not affected.

"Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72 (b)(2)(iv)(B). The expected actuation of the AFW system (an engineered safety feature) is being reported as an eight-hour report under 10 CFR 50.72 (b)(3)(iv)(A).

"There was no impact to the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The cause of the main turbine trip was due to the loss of both main feed pumps due to a loss of secondary power. The cause of the loss of secondary power is still being investigated.