Event Notification Report for June 24, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
06/23/2025 - 06/24/2025
Agreement State
Event Number: 57784
Rep Org: Texas Dept of State Health Services
Licensee: DAE and Associates LTD
Region: 4
City: Rosenberg State: TX
County:
License #: 03923
Agreement: Y
Docket:
NRC Notified By: Sindiso Ncube
HQ OPS Officer: Ernest West
Licensee: DAE and Associates LTD
Region: 4
City: Rosenberg State: TX
County:
License #: 03923
Agreement: Y
Docket:
NRC Notified By: Sindiso Ncube
HQ OPS Officer: Ernest West
Notification Date: 06/25/2025
Notification Time: 19:06 [ET]
Event Date: 06/24/2025
Event Time: 00:00 [CDT]
Last Update Date: 06/25/2025
Notification Time: 19:06 [ET]
Event Date: 06/24/2025
Event Time: 00:00 [CDT]
Last Update Date: 06/25/2025
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
Bywater, Russell (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
ILTAB, (EMAIL) (EMAIL)
CNSNS (Mexico), - (EMAIL)
Bywater, Russell (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
ILTAB, (EMAIL) (EMAIL)
CNSNS (Mexico), - (EMAIL)
AGREEMENT STATE REPORT - STOLEN GAUGE
The following information was provided by the Texas Department of State Health Services (the Department) via email:
"On June 25, 2025, the licensee notified the Department of the theft of a moisture density gauge. The gauge, a Troxler 3430, contains an 8 millicurie (mCi) cesium-137 sealed source and a 40 mCi americium-241/beryllium sealed source. The theft occurred in Fort Bend County on June 24, 2025. The radiation safety officer (RSO) stated that a technician, after completing his work at a job site, placed the gauge in the back of his pickup truck. The technician placed the gauge in its transport container which was then secured with double locks. The RSO stated that the technician left the job site and drove to a gas station. It was at the gas station that he noticed that the gauge was missing. The locks securing the gauge transport container had been broken, and the container, including the gauge, stolen. The technician reported the theft to the RSO and the Harris County Sheriff's department. The licensee stated that the source rod was in the secured and locked position at the time of the incident. The licensee also stated that no unintended exposure to the public exceeding dose limits is expected due to this incident.
"Additional information will be provided in accordance with SA 300 reporting requirements."
Texas incident report number: 10205
Texas NMED number: TX250030
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
The following information was provided by the Texas Department of State Health Services (the Department) via email:
"On June 25, 2025, the licensee notified the Department of the theft of a moisture density gauge. The gauge, a Troxler 3430, contains an 8 millicurie (mCi) cesium-137 sealed source and a 40 mCi americium-241/beryllium sealed source. The theft occurred in Fort Bend County on June 24, 2025. The radiation safety officer (RSO) stated that a technician, after completing his work at a job site, placed the gauge in the back of his pickup truck. The technician placed the gauge in its transport container which was then secured with double locks. The RSO stated that the technician left the job site and drove to a gas station. It was at the gas station that he noticed that the gauge was missing. The locks securing the gauge transport container had been broken, and the container, including the gauge, stolen. The technician reported the theft to the RSO and the Harris County Sheriff's department. The licensee stated that the source rod was in the secured and locked position at the time of the incident. The licensee also stated that no unintended exposure to the public exceeding dose limits is expected due to this incident.
"Additional information will be provided in accordance with SA 300 reporting requirements."
Texas incident report number: 10205
Texas NMED number: TX250030
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
Power Reactor
Event Number: 57778
Facility: Sequoyah
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Craig Youngblood
HQ OPS Officer: Robert A. Thompson
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Craig Youngblood
HQ OPS Officer: Robert A. Thompson
Notification Date: 06/24/2025
Notification Time: 02:23 [ET]
Event Date: 06/24/2025
Event Time: 00:14 [EDT]
Last Update Date: 06/24/2025
Notification Time: 02:23 [ET]
Event Date: 06/24/2025
Event Time: 00:14 [EDT]
Last Update Date: 06/24/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Blamey, Alan (R2DO)
Blamey, Alan (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 100 | Power Operation | 0 | Hot Standby |
UNIT 1 MANUAL REACTOR TRIP
The following information was provided by the licensee via phone and email:
"At 0014 EDT on 6/24/2025, Sequoyah Unit 1 operators performed a manual reactor trip. All safety systems responded normally, and the plant is currently stable in mode 3 (hot standby) at normal operating temperature and pressure. Unit 1 was manually tripped due to lowering steam generator water levels caused by a secondary control system malfunction.
"Unit 2 is not impacted and remains at 100 percent power in mode 1.
"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) and in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the auxiliary feedwater system.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
The following information was provided by the licensee via phone and email:
"At 0014 EDT on 6/24/2025, Sequoyah Unit 1 operators performed a manual reactor trip. All safety systems responded normally, and the plant is currently stable in mode 3 (hot standby) at normal operating temperature and pressure. Unit 1 was manually tripped due to lowering steam generator water levels caused by a secondary control system malfunction.
"Unit 2 is not impacted and remains at 100 percent power in mode 1.
"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) and in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the auxiliary feedwater system.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
Power Reactor
Event Number: 57779
Facility: Sequoyah
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Craig Youngblood
HQ OPS Officer: Ernest West
Region: 2 State: TN
Unit: [2] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Craig Youngblood
HQ OPS Officer: Ernest West
Notification Date: 06/24/2025
Notification Time: 05:16 [ET]
Event Date: 06/24/2025
Event Time: 03:51 [EDT]
Last Update Date: 06/24/2025
Notification Time: 05:16 [ET]
Event Date: 06/24/2025
Event Time: 03:51 [EDT]
Last Update Date: 06/24/2025
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Blamey, Alan (R2DO)
Blamey, Alan (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | M/R | Y | 100 | Power Operation | 0 | Hot Standby |
UNIT 2 MANUAL REACTOR TRIP
The following information was provided by the licensee via phone and email:
"At 0351 EDT on 6/24/25, Sequoyah Unit 2 operators performed a manual reactor trip. All safety systems responded normally, and the plant is currently stable in mode 3 (hot standby) at normal operating temperature and pressure. Unit 2 was manually tripped due to lowering level in the loop 1 steam generator caused by main feedwater regulating valve malfunction.
"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) and in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the auxiliary feedwater system.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
The following information was provided by the licensee via phone and email:
"At 0351 EDT on 6/24/25, Sequoyah Unit 2 operators performed a manual reactor trip. All safety systems responded normally, and the plant is currently stable in mode 3 (hot standby) at normal operating temperature and pressure. Unit 2 was manually tripped due to lowering level in the loop 1 steam generator caused by main feedwater regulating valve malfunction.
"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) and in accordance with 10 CFR 50.72(b)(3)(iv)(A) as an event that results in a valid actuation of the auxiliary feedwater system.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."