Event Notification Report for July 25, 2024

AGREEMENT STATE REPORT - LOST I-125 SEED

The following information was provided by the Arizona Department of Health Services (the Department) via email:

"The Department received notification from the licensee of a lost I-125 seed used for localization. A patient was implanted with (1) approximately 0.150 mCi I-125 seed on July 15, 2024. The patient returned to the hospital on July 16, 2024, to have the tissue, including the seed, removed. When the surgeon attempted to locate the seed, they were unable to detect it. The operating room and patient were surveyed but the seed was not located. The Department has requested additional information and continues to investigate the event.

"Additional information will be provided as it is received in accordance with SA-300."

Arizona Incident Number: 24-009

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 - STOLEN TROXLER DENSITY GAUGE

The following information was provided by the Pennsylvania Department Bureau of Radiation Protection (the Department) via email:

"On July 18, 2024, the Department was notified of a stolen nuclear density gauge. This event is reportable within 24-hours per 10 CFR 20.2201(a)(1)(i).

"On July 17, 2024, an employee of the licensee reported to police that a nuclear density gauge was stolen from their vehicle between 1830-2250 EDT. Local police are aware of the incident. The Department has been in contact with the licensee and will update this event as soon as more information is provided.

"Manufacturer & Model Number: Troxler Electronic Laboratories
"Model Number: 3440
"Serial Number: 87955
"Isotope & Activity: Cs-137, 9 millicuries; Am-241:Be, 44 millicuries"

Pennsylvania Incident Number: 240016

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

EN Revision Imported Date: 7/25/2024

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)

OFFSITE NOTIFICATION

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

"At 1046 EDT on 7/24/2024, fourteen Ashtabula County emergency response sirens were inadvertently activated during system maintenance. Ashtabula County Emergency Management Agency was contacted and made aware of the situation. This notification is being made solely as a four-hour, non-emergency notification for a notification of other government agencies in accordance with 10 CFR 50.72(b)(2)(xi). There was no impact to the health and safety of the public or plant personnel. The NRC resident inspector has been notified of the issue."

TECHNICAL SPECIFICATION VIOLATION

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

"Minimum staffing [was] not met under Missouri University of Science and Technology Reactor (MSTR) Technical Specification (TS) 6.1.3.1(a) [for approximately one hour].

"At 1400 CDT, on July 24, 2024, the MSTR conducted a planned shutdown from 40 kW in support of a thermal power calibration. At approximately 1410, the control room operator left the control room for the reactor bay to perform additional power calibration data collection. At approximately 1510, the radiation safety officer (RSO) passed by the control room and observed that the magnet key remained in the console. The operator was promptly notified and secured the key. The operator notified the reactor manager and senior reactor operator on duty (shift supervisor) by approximately 1530, who discussed the issue with the facility director.

"During the time period of 1410 to 1510, the MSTR did not meet the TS definition for reactor secured, as the magnet key remained in the console. As such, without an operator in the control room, the minimum staffing requirements of TS 6.1.3.1(a) were not met, as this specification states: `1. The minimum staffing when the reactor is not secured shall be: a) A certified reactor operator in the control room.' It is noted that the reactor was shut down and the control rods remained inserted for the duration of the event.

"The event has been entered into the facility corrective action program as CAP-2024-001, and the NRC project manager will be notified."

POSITIVE FITNESS FOR DUTY TEST

The following information was provided by the licensee via email:

"On July 24, 2024, a licensed operator violated the station's fitness for duty (FFD) policy. The employee's unescorted access to South Texas Project has been terminated. The event was determined to be reportable under 10 CFR 26.719(b)(2)(ii).

"The NRC resident inspector has been notified."