Event Notification Report for September 30, 2024

AGREEMENT STATE REPORT - STOLEN SOURCE

The following is a summary of information that was provided by the New Mexico Radiation Control Program via phone and email:

During the weekend, Acme Environmental, Inc. (the licensee) was burglarized. An XRF lead paint analyzer, model Heuresis Pb200i, containing 5 mCi of Co-57 was stolen, along with numerous other items. The licensee notified the police, and the police are actively investigating.

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

MANUAL REACTOR TRIP ON LOWERING CONDENSER VACUUM

The following information was provided by the licensee via phone:

"At 0346 EDT on 9/27/24, with Unit 1 in mode 1 at 54 percent power, the reactor was manually tripped due to degrading condenser vacuum secondary to environmental conditions. The trip was not complex with all systems responding normally post trip. Closure of containment isolation valves (CIVs) in multiple systems occurred. Operations responded and stabilized the plant.

"The reactor protection system actuation while critical event is being reported as a 4-hour non-emergency notification per 10 CFR 52.72(b)(2)(iv)(B). Additionally, it is reportable under 10 CFR 52.72(b)(3)(iv)(a) as an event that results in a valid actuation of the CIVs.

"There was no impact on 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:

Decay heat removal is via steam bypass to the main condenser. Unit 2 was not affected.

MANUAL REACTOR TRIP DUE TO LOSS OF CONDENSER VACUUM

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

"At 0748 EDT on 9/27/24, Catawba Unit 2 was manually tripped due to loss of condenser vacuum. The Unit 2 auxiliary feedwater (AFW) system started automatically as expected. Decay heat is being removed by the steam generators and discharging to the condenser.

"Due to the Unit 2 reactor protection system actuation while critical, this event is being reported as a four-hour, nonemergency notification per 10 CFR 50.72(b)(2)(iv)(B). The automatic start of the Unit 2 AFW system is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(iv)(A).

"On Unit 1, it was determined that at 0746, all trains of the Unit 1 AFW were inoperable when the Unit 1 hotwell temperature exceeded the operability limit for the AFW system. Therefore, this condition is being reported as an eight-hour, nonemergency notification per 10 CFR 50.72(b)(3)(v). The affected safety function was restored on 9/27/24 at 0851 EDT when the Unit 1 hotwell temperature returned below the operability limit for the AFW 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 additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

The loss of vacuum for both Unit 1 and Unit 2 was due to loss of power to cooling tower fans. The suspected cause of loss of cooling tower fans was due to water intrusion due to Hurricane Helene.

FITNESS FOR DUTY

The following information was provided by the licensee via email:

"On September 17, 2024, the site identified that an individual assigned to perform fitness for duty (FFD) program duties, who should have been part of the fitness for duty program random testing pool, had been inadvertently removed during a recent computer system upgrade. The individual was reprocessed and placed back into the FFD program on September 18, 2024. This was determined to be an isolated incident as it was confirmed that no other individuals required to be in the program were removed."

FITNESS FOR DUTY

The following information was provided by the licensee via email:

"On September 17, 2024, the site identified that an individual assigned to perform fitness for duty (FFD) program duties, who should have been part of the fitness for duty program random testing pool, had been inadvertently removed during a recent computer system upgrade. The individual was reprocessed and placed back into the FFD program on September 18, 2024. This was determined to be an isolated incident as it was confirmed that no other individuals required to be in the program were removed."

HIGH PRESSURE COOLANT INJECTION INOPERABLE

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

"At 1822 CST on September 27, 2024, Grand Gulf Nuclear Station (GGNS) was conducting surveillance testing on the high pressure core spray (HPCS) division Ill diesel generator. Following initiation of the test signal, the HPCS pump room cooler start time exceeded the surveillance procedure allowance of less than or equal to 20 seconds. The HPCS pump room cooler started in 26.2 seconds. HPCS was already inoperable for performance of the surveillance testing.

"The event is being reported in accordance with 10 CFR 50.72(b)(3)(v)(D) as an event or condition which could have prevented the fulfillment of a safety function.

"Troubleshooting is in progress. HPCS, a single-train system, will remain inoperable until the condition is corrected.

"All sources of offsite power are available. No other safety systems are inoperable. Reactor core isolation cooling was verified to be operable per GGNS Technical Specification 3.5.1.B.1.

"The NRC Senior Resident Inspector has been notified."

AUTOMATIC REACTOR TRIP DUE TO TURBINE TRIP

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

"At 05:56 EDT on 09/29/2024, with Unit 1 in Mode 1 at 100 percent power, the reactor automatically tripped due to a turbine trip. The motor driven auxiliary feedwater (MDAFW) level control valves (LCV) for loop 1 failed to respond from the main control room. All others systems responded normally post-trip.

"Operations responded and stabilized the plant. Decay heat is being removed by the auxiliary feedwater (AFW) and steam dump systems. Unit 2 is currently stable in Mode 6 for a maintenance outage and was 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) and an eight-hour, non-emergency notification per 10 CFR 50.72 (b)(3)(iv)(A) as an event that results in a valid actuation of the AFW system. The AFW system started automatically and is operating as designed with the exception of the MDAFW LCVs for loop 1.

"There was no impact on 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 facility is in a 72 hour technical specification related to the auxiliary feedwater system. Sequoyah does not consider this to be a complex trip. The turbine trip is due to an electrical failure, and is still under investigation. Offsite power is qualified with no abnormalities.