Event Notification Report for May 28, 2024

AGREEMENT STATE REPORT - STUCK SOURCE

The following information was provided by North Dakota Department of Health via email:

"At 0955 CDT, Monday, May 20, 2024, the North Dakota Department of Health received a call from the Corporate, Radiation Safety Officer (RSO) of Braun Intertec Corporation (Braun). Braun's North Dakota [state] RSO received a phone call on Friday, May 17, 2024, at 0941 from a Braun radiographer on site indicating a 40.5 curie Iridium-192 source (QSA Model 424-9, S/N 91621M) was unable to be returned into the radiographic device (QSA Model 880 Delta S/N D15651). The radiographer had initiated a crank out of the source and immediately was aware something was not working properly. Attempts to return the source to the locked position failed. The RSO indicated that the source may not have been fully out of the radiographic device and inside the guide tube, but may have been out of the locked position yet still inside the radiographic device.

"The North Dakota RSO arrived on site at 1205 to perform the source retrieval. The Iridium-192 source was retracted into the radiographic device at 1315.

"Initial investigation indicates no dose exceedances/overexposures occurred during the retrieval process, and a faulty control assembly is the cause of the misconnect event. The control assembly has been removed from service."

North Dakota's reference number: ND240002.

AGREEMENT STATE REPORT - POTENTIAL OVER EXPOSURE

The following information was provided by the Louisiana Radiation Protection Division via email:

"The Louisiana Radiation Protection Division was notified on May 20, 2024, by the Radiation Safety Officer (RSO) for SPEC, that an employee had a 10.695 REM exposure on the Lanadauer badge for the month of April 2024. The employee works in shipping. The licensee does not know if it was an actual overexposure or not. The licensee will be speaking with the employee on 5/21/2024."

Event Report ID No.: LA 20240006

TECHNICAL SPECIFICATION REQUIRED SHUTDOWN

The following information was provided by the licensee via email:

"At 0400 EDT on May 23, 2024, a technical specification required shutdown was initiated at Perry. Technical specification action 3.4.5 condition B [unidentified reactor coolant system leakage exceeds 5 gallons per minute] was entered on May 23, 2024 at 0000 with a required action to reduce leakage to within limits within 4 hours, due by 0400 on May 23, 2024. This required action was not completed within the completion time, therefore, a technical specification required shutdown was initiated, and this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(i).

"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 reactor coolant leakage was stable at approximately 6 gallons per minute.

FITNESS FOR DUTY PROGRAMMATIC FAILURE

The following information was provided by the licensee via email:

"During a security inspection, it was determined that some past events at Entergy sites that were not reported may have met the reporting criterion of 10 CFR 26.719(b)(4). As a result, the following events at Arkansas Nuclear One, Units 1 and 2 are now being conservatively reported: On February 2, 2023, a condition report was written to document that an individual who should have been placed in a follow-up fitness for duty (FFD) program was not tested according to this program. On September 6, 2023, a subsequent condition report was written to document that a different individual who should have been placed in a follow-up FFD program was not tested according to this program. The resident inspector has been notified."

FITNESS FOR DUTY PROGRAMMATIC FAILURE

The following information was provided by the licensee via email:

"During a security inspection, it was determined that some past events at Entergy sites that were not reported may have met the reporting criterion of 10 CFR 26.719(b)(4). As a result, the following event at Grand Gulf, Unit 1 is now being conservatively reported: On May 11, 2023, a condition report was written to document that an individual who should have been placed in a follow-up fitness for duty program was not tested according to this program. The resident inspector has been notified."

FITNESS FOR DUTY PROGRAMMATIC FAILURE

The following information was provided by the licensee via email:

"During a security inspection, it was determined that some past events at Entergy sites that were not reported may have met the reporting criterion of 10 CFR 26.719(b)(4). As a result, the following events at River Bend Station, Unit 1 are now being conservatively reported: On March 21, 2023, a condition report was written to document that an individual who should have been placed in a follow-up fitness for duty (FFD) program was not tested according to this program. On May 11, 2023, a subsequent condition report was written to document that a different individual who should have been placed in a follow-up FFD program was not tested according to this program. The resident inspector has been notified."

FITNESS FOR DUTY PROGRAMMATIC FAILURE

The following information was provided by the licensee via email:

"During a security inspection, it was determined that some past events at Entergy sites that were not reported may have met the reporting criterion of 10 CFR 26.719(b)(4). As a result, the following event at Waterford Steam Electric Station, Unit 3 is now being conservatively reported: On May 15, 2023, a condition report was written to document that an individual who should have been placed in a follow-up fitness for duty program was not tested according to this program. The individual was no longer badged at Waterford 3 but is currently badged at another Entergy site. The resident inspector has been notified."

AUTOMATIC SCRAM DUE TO TURBINE TRIP SIGNAL

The following information was provided by the licensee via email:

"At 2223 CDT on May 23, 2024, with Quad Cities Unit 2 at 38 percent power, the reactor automatically tripped due to a turbine trip signal resulting in main stop valve closure, creating a valid reactor protection system signal. Reactor vessel level reached the low-level set-point following the scram, resulting in valid Group II and Group III containment actuation signals. The trip was not complex with all systems responding as expected post-trip. 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) for the Group II and Group III isolation.

"Operations responded using their emergency operating procedures and stabilized the plant in mode 3. Decay heat is being removed by discharging steam to the main condenser using the turbine bypass valves.

"Unit 1 remains at 100 percent power.

"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:

Unit 2 was at a reduced power for maintenance.

PART 21 - DEFECT WITH EMERGENCY DIESEL GENERATOR VOLTAGE REGULATOR

The following information was provided by Paragon Energy Solutions, LLC via email:

"Paragon has identified a defect in one voltage regulator supplied to AEP DC Cook with serial number NLI-3S7950GR751A1-1007.

"Pursuant to 10CFR Part 21  21.21(d)(3)(i), Paragon is providing initial notification of a defect associated with the emergency diesel generator (EDG) voltage regulator. The voltage regulator was refurbished under the client purchase order 01600229, project number 351030025. Part of the refurbishment involved complete replacement of the units wiring, physical inspection and testing of the unit to Paragon approved acceptance testing instructions. The refurbished unit was supplied to the customer in December 2023. Prior to installation (March 2024), the unit successfully passed bench testing at the plant. During post installation testing, the EDG was started, and the output voltage pegged high and was not controllable. DC Cook subsequently removed the voltage regulator and documented the non-conformance. DC Cook troubleshooting determined the unit was mis-wired. The unit [voltage regulator] was returned to Paragon, and inspection confirmed the plant's diagnosis. The identified mis-wire affects the system circuitry by placing silicon controlled rectifier 5CD in a reverse biased position. The reversed biased rectifier blocks the flow of current which creates an open circuit condition. This open circuit condition causes the output voltage to max out, and does not allow the output voltage to be adjusted. This condition, if left uncorrected, could contribute to a substantial safety hazard and is reportable in accordance with 10CFR Part 21.

"Date of Discovery: May 9, 2024

"Reportability Determined: May 23, 2024

"Paragon has entered this condition in our corrective action program, and we have custody of the effected unit. The extent of condition is limited to this unit supplied to DC Cook. Paragon has determined there is no action necessary for DC Cook at this time."

Affected plant: DC Cook

CONTROLLED SUBSTANCE FOUND IN PROTECTED AREA

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

"A 50 ml bottle of vodka was found in the Unit 3 debris basket on the exterior of the intake structure. The bottle likely came from the ultimate heat sink (Niantic Bay) during normal backwash operations by the system that collects debris.

"Security has discarded the contraband. 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 bottle was found unsealed.

TWO OF THREE ESSENTIAL CHILLED WATER TRAINS DECLARED INOPERABLE

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

"At 0210 CDT 5/24/24, essential chiller 'A' train and cascading equipment was declared inoperable for maintenance to correct a temperature control malfunction.

"At 0720 CDT 5/26/24, essential cooling water 'B' train and cascading equipment (including 'B' train essential chiller) was declared inoperable due to a through wall leak discovered on the essential cooling water return header temperature element thermal well.

"This condition resulted in an inoperable condition on two out of three safety trains for the accident mitigating function, including the train 'A' and train 'B' high head safety injection, low head safety injection, containment spray, electrical auxiliary building heating ventilation and air conditioning (HVAC), and essential chilled water. All 'C' train safety related equipment remains operable.

"This was determined to be reportable within 8 hours as required by 10CFR50.72(b)(3)(v)(D).

"NRC Resident Inspector has been notified."