Event Notification Report for July 30, 2024

AGREEMENT STATE REPORT - LOST SOURCE

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

"The NYSDOH received an email from the radiation safety officer (RSO) on July 22, 2024, to report a lost Fe-55 source. The make and model of the missing source was not disclosed; however, NYSDOH is requesting additional information and will provide this information once available. The source serial no. is 55-1.1-8 and was last assayed 10/1/2015. At the time of manufacture and distribution, this source was 10 mCi.

"The source in question was last seen during routine inventory on January 5, 2023. Following this inventory, this source was not accounted for on March 23, 2023. It was believed that this source may have been utilized by an authorized user between January 5, 2023, and March 23, 2023. However, after many discussions between the authorized user and Stony Brook University's radiation safety office, it was confirmed that the source in question was officially lost on 7/18/2024. Decay calculations suggest that the missing Fe-55 source is approximately 1.07 mCi to date. As this source was last inventoried on January 5, 2023, it is estimated that the Fe-55 source was approximately 1.58 mCi at the time it was last confirmed as present in the storage area. This activity is approximately 15.8 times the quantity for Fe-55 requiring labeling as stated in Appendix C to 10 CFR 20. The loss of this source meets the reportability criteria in 10 CFR 20.2201(a)(1)(ii).

"It is not believed that this source may cause any incidental doses which may exceed the limits in Subparts C or D of 10 CFR 20. Furthermore, the loss of this source would not be expected to have any negative implications on public health. NYSDOH is monitoring this incident and has assigned incident number 1493 to track this event. Additional information will be provided to NMED once available."

Event Report ID No. NY-24-06
NYSDOH Incident Number: 1493

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 - ATTEMPTED THEFT OF CATEGORY 2 MATERIAL

The Texas Department of State Health Services reported an apparent attempted theft of Category 2 radioactive material from the licensee. Local law enforcement was informed.

Texas Incident Number: 10113
SID-03254

Notified DHS SWO, FEMA Ops, USDA Ops, HHS Ops, DOE Ops, CISA Central, EPA EOC, FDA EOC, Nuclear SSA, FEMA National, CWMD Watch Desk

THIS MATERIAL EVENT CONTAINS A 'Category 2' LEVEL OF RADIOACTIVE MATERIAL

Category 2 sources, if not safely managed or securely protected, could cause permanent injury to a person who handled them, or were otherwise in contact with them, for a short time (minutes to hours). It could possibly be fatal to be close to this amount of unshielded radioactive material for a period of hours to days. These sources are typically used in practices such as industrial gamma radiography, high dose rate brachytherapy and medium dose rate brachytherapy. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf

AGREEMENT STATE REPORT - FIRE IN EQUIPMENT CONTAINING RADIOACTIVE MATERIAL

The following information was provided by the Louisiana Department of Environmental Quality (LA DEQ) via email:

"This event is considered [an] equipment fire. The licensee had a vent hood equipment electrical fire. The fire occurred at 0630 [CDT] on July 23, 2024. The event was not reported until 1445 on July 23, 2024.

"The vent contained radioactive material waste. The majority of the waste was radioactive iodine. This event is under investigation and [LA DEQ] will have an inspector sent out.

"According to the licensee, there was no release. All material in the vent hood remained intact.

"The local fire department was called out to the location to put out the fire."

LA DEQ Event Report Number: LA20240008

EN Revision Imported Date: 7/30/2024

EN Revision Text: NOTIFICATION OF UNUSUAL EVENT DUE TO LOSS OF OFFSITE POWER

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

A Notification of Unusual Event was declared by South Texas Project Unit 1 at 0718 CDT for emergency action level (EAL) SU.1, loss of all offsite power for greater than 15 minutes, following a fire in the switchyard. Unit 1 tripped following the loss of power and is stable in Mode 3. Unit 2 reduced power to 90 percent but was otherwise unaffected by this event. Offsite services responded to the switchyard fire. The fire was extinguished at 0925 CDT.

There is no radioactive release and no threat to public safety.

The licensee notified state and local authorities and the NRC senior resident inspector.

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).

* * * UPDATE ON 7/24/2024 AT 1154 EDT FROM CHRIS VAN FLEET TO ERNEST WEST * * *

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

"At 0702 CDT on 7/24/2024, with Unit 1 in Mode 1 at 100 percent power, the Unit 1 reactor automatically tripped due to loss of offsite power. The trip was not complex, with all systems responding normally post-trip. No equipment was inoperable prior to the event that contributed to the event or adversely impacted plant response to the scram.

"Operations responded and stabilized the plant. Decay heat is being removed by steam generator power operated relief valves (PORV). Unit 2 was reduced in power to approximately 90 percent power due to conditions in the switchyard.

"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).

"There was no impact on the health and safety of the public or plant personnel. The NRC resident inspector has been notified."

Notified R4DO (Azua)

* * * UPDATE ON 7/24/2024 AT 1259 EDT FROM CHRIS MCRARY TO ERNEST WEST * * *

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

At 1146 CDT, South Texas Project Unit 1 terminated the previously declared Notification of Unusual Event due to restoration of an offsite source of electrical power.

Notified R4DO (Azua), NRR EO (McKenna), IR MOC (Crouch), DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

* * * UPDATE ON 7/24/2024 AT 1555 EDT FROM CHRIS VAN FLEET TO ERNEST WEST * * *

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

For the 10 CFR 50.72(b)(3)(iv)(A) reporting requirements:

"At 0702 CDT on 7/24/2024, with both Unit 1 and 2 in Mode 1 at 100 percent power, the South Texas Project (STP) north and south switchyard electrical buses were de-energized.

"In Unit 1, all emergency diesel generators (EDGs) 11, 12, and 13 automatically started in response to loss of offsite power on train `A', `B', and `C' engineered safety feature (ESF) buses.

"Also in Unit 1, trains `A', `B', and `C' of the auxiliary feedwater (AFW) system automatically started.

"In Unit 2, EDG 22 automatically started in response to loss of offsite power on the train `B' ESF bus.

"Also in Unit 2, train `B' of the AFW system automatically started.

"This event is reportable under 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in the valid actuation of a pressurized water reactor auxiliary feedwater system (50.72(b)(3)(iv)(B)(6)) and emergency alternating current (AC) electrical power system (50.72(b)(3)(iv)(B)(8)). There was no impact on the health and safety of the public or plant personnel. The NRC resident inspector has been notified."

For the 10 CFR 50.72(b)(2)(xi) reporting requirement:

"A news release was completed at 1140 CDT on 7/24/2024, by South Texas Project on the declaration of the Unusual Event. This media release is being reported in accordance with 10 CFR 50.72(b)(2)(xi): Any event or situation, related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or notification to other government agencies has been or will be made."

Notified R4DO (Azua)

* * * UPDATE ON 7/29/2024 AT 1558 EDT FROM MATT DUGGER TO IAN HOWARD * * *

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

"After a review of station logs, it was determined that there was not a loss of all offsite AC power to Unit 1 related to the event that occurred on July 24, 2024. An offsite AC power source was available through the 138 kV transmission line.

"The NRC Resident Inspector has been notified."

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

At this time the licensee is not retracting the declaration of emergency action level 'SU.1'.

Notified R4DO (Werner)

AUTOMATIC REACTOR TRIP

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

"At 1837 EDT on 7/28/24, with Unit 1 in mode 1 at 100 percent power, the reactor automatically tripped due to inadvertent closure of a main steam isolation valve. During the trip, auxiliary feedwater actuated. All other systems responded normally post-trip. Operations stabilized the plant in mode 3. Decay heat is being removed by atmospheric dump valves and auxiliary feedwater. Unit 2 is not affected.

"This event is being reported pursuant to 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A)."

The NRC resident inspector has been notified.