Event Notification Report for November 20, 2023

EN Revision Imported Date: 11/20/2023

EN Revision Text: PART 21 INTERIM REPORT - DEVIATION ASSOCIATED WITH AN SMB-1 GEARED LIMIT SWITCH ASSEMBLY

The following information was provided by Flowserve via phone and email:

"The purpose of this letter is to provide written notification of an evaluation of a deviation in a basic component in accordance with 10 CFR21.21(a)(2). This interim report pertains to actuator geared limit switch assemblies contained in SMB-1 actuators supplied to Bopp & Reuther Valves for use in safety related applications at Bruce Nuclear Generating Station.

"Flowserve - Limitorque was contacted by Bruce Power who reported a malfunction of an actuator geared limit switch (GLS) assembly which occurred while attempting to set the valve travel position limits prior to placing the actuator into service. Site inspections of the GLS assembly revealed damage to the GLS drive pinion which engages with the actuator drive train. Site photos and dimensional measurements of the drive pinion requested by Flowserve indicate that the GLS was assembled with an incorrect drive pinion resulting in the malfunction. Use of an incorrect subcomponent in the assembly constitutes the deviation to the design being evaluated. The actuator GLS assembly is a safety related component. A malfunction of the GLS in service has the potential to affect the safety function of the actuator.

"The assembly containing the deviation is a 4-train geared limit switch (GLS) assembly part number 10168 supplied in SMB-1 actuators manufactured on Flowserve order 175377.001 Three actuators (serial numbers L1226986, L1226987, & L1226988) were shipped to Bopp & Reuther Valves on 2/4/2020.

"Flowserve's evaluation of this issue is ongoing and will not be completed within 60 days. The evaluation is expected to be completed by 11/17/2023 pending return of the affected components to Flowserve for inspection. Questions concerning this notification can be directed to Chris Shaffer, Quality Manager."

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

This issue was identified at a Canadian reactor plant owned by Bruce Power. The Quality Manager at Flowserve is not currently aware of any affected US reactor plants.

* * * UPDATE ON 11/17/2023 AT 0914 EST FROM CHRISTOPHER SHAFFER TO ERIC SIMPSON * * *

Flowserve Quality Assurance Manager submitted the Final Part 21 Report pertaining to a deviation in a basic component in accordance with 10 CFR 21.21(a)(2). The report concluded that the evaluated deviation constitutes a reportable defect affecting three actuators listed in the final report.

Notified R1DO (Defrancisco), R2DO (Miller), R3DO (Feliz-Adorno), R4DO (Vossmar), and Part 21 Reactors (email).

AGREEMENT STATE REPORT - PATIENT RECEIVED 45 PERCENT UNDERDOSE

The following was received from the South Carolina Department of Health and Environmental Control (Department) via phone and email:

"The South Carolina Department of Health and Environmental Control was notified via telephone at approximately 0930 EST on 11/10/23 that a medical event had been discovered by the licensee on 11/09/23 at approximately 1700 EST. The Medical University of South Carolina (MUSC) reported an underdose to a patient's liver during a Y-90 microsphere procedure by 45 percent of the prescribed 500 Gray (Gy) dose. MUSC estimates that the patient received 276 Gy of the intended 500 Gy dose. The licensee reported that the total dose or activity delivered differs from the prescribed dose or activity, as documented in the written directive, by 20 percent or more.

"The licensee reports no immediate or ongoing concerns to public health and safety. Department inspectors will be dispatched to the facility to investigate this event. This event is still under investigation by the South Carolina Department of Health and Environmental Control."

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

CONCURRENT REPORT FOR DEGRADED CONNECTOR

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

"Pursuant to 10 CFR 70 Appendix A (c), Framatome is making this concurrent report:

"On November 2, 2023, Framatome made a courtesy telephone call to the Washington Department of Health (WDOH) about a degraded flexible connector on an exhaust duct downstream of the final HEPA filter.

"On November 3, 2023, WDOH requested that Framatome submit a report within ten days regarding this notification. Framatome will be submitting the requested report today, [November 13, 2023]."

AUTOMATIC REACTOR TRIP

The following information was provided by the licensee via email:

"At 0227 EST on 11/16/23, Calvert Cliffs Unit 2 experienced an automatic trip from the reactor protection system (RPS) based on reactor trip bus undervoltage (UV). At that time, a loss of U-4000-22 (13 kV to 4 kV transformer) caused a loss of 22, 23, and 24 4 kV busses. This resulted in a loss of both motor generator (MG) sets causing the reactor trip bus UV. The loss of 22 and 23 4 kV non-safety related busses resulted in a loss of main feedwater. Auxiliary feedwater (AFW) was manually initiated and is feeding both steam generators. The 2B diesel generator (DG) started and restored the 24 4 kV safety related bus. Heat removal is via the normal turbine bypass valves to the main condenser.

"RPS actuation is reportable under 10 CFR 50.72(b)(2)(iv)(B) - 4 hour report
"ESFAS (engineering safety features actuation system) actuation (2B DG start on UV) is reportable under 10 CFR 50.72(b)(3)(iv)(A) - 8 hour report
"AFW operation is reportable under 10 CFR 50.73(a)(2)(iv)(A) - 60 day report

"The NRC Senior Resident Inspector has been notified."

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

All rods fully inserted. There was no impact on Unit 1 operations. Unit 2 is stable in mode 3.

* * * UPDATE ON AT 0940 EST FROM KERRY HUMMER TO ADAM KOZIOL * * *

"ESFAS actuation (AFW manual initiation) is reportable under 10CFR50.72(b)(3)(iv)(A) - 8 hour report"

Notified R1DO (Defrancisco).

FAILED FITNESS FOR DUTY TEST

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

"At 0906 Eastern Standard Time (EST) on November 16, 2023, it was determined that a non-licensed employee supervisor failed a test specified by the Fitness for Duty (FFD) testing program. The individual's authorization for site access has been removed.

"The NRC Resident Inspector has been notified."

ESSENTIAL CHILLER TRAINS INOPERABLE

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

"11/05/23, 2200 CST: Essential Chiller 'B' train and associated cascading equipment were declared INOPERABLE for planned maintenance. Unit 2 entered the Configuration Risk Management Program as required by Technical Specifications on 11/12/23 at 2200.

"11/16/23, 1541: Essential Chiller 'C' train and associated cascading equipment were declared INOPERABLE due to an unexpected material condition causing the Essential Chiller to trip. The most limiting [Limiting Condition of Operability] LCO is 3.7.7, Action c.

"This condition resulted in the INOPERABILITY of two of the three safety trains required for the accident mitigating function including: High Head Safety Injection, Low Head Safety Injection, Containment Spray, Electrical Auxiliary Building HVAC, Control Room Envelope HVAC, Essential Chilled Water.

"This is an 8 hour reportable condition per 10CFR50.72(b)(3)(v)(D) because it could affect the ability to mitigate the consequences of an accident.

"A risk analysis was performed for the equipment INOPERABILITY and mitigating actions have been taken per site procedures. All 'A' train equipment remains operable."

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

The 'B' train Emergency Diesel Generator was also inoperable due to planned maintenance and continues to be inoperable. It was considered in the Configuration Risk Management Program and it was determined this condition could be maintained. LCO 3.7.7, Action c requires reactor shutdown within 72 hours.

MANUAL REACTOR SCRAM

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

"On November 17, 2023, at 2215 CST, River Bend Station (RBS) was operating at 30 percent reactor power performing plant startup activities when an isolation of low-pressure feedwater string `A' occurred. The team entered applicable alternate operating procedures and inserted control rods to exit the restricted region of the power to flow map. Feedwater temperature continued to lower until it challenged the prohibited region of the AOP-0007 graph requiring a reactor scram. The team inserted a manual reactor scram at 2355 from 24 percent reactor power. All control rods fully inserted and there were no complications. All systems responded as designed. Currently RBS Unit 1 is stable with reactor level being maintained 10 to 51 inches with feed and condensate, and pressure being maintained 500 to 1090 psig using steam drains.

"This event is being reported under 10 CFR 50.72(b)(2)(iv)(B), as any event or condition that results in actuation of the Reactor Protection System (RPS) when the reactor is critical and 10 CFR 50.72(b)(3)(iv)(A) Specified System Actuation as result of Group 3 isolations.

"The NRC Senior Resident inspector has been notified.

"No radiological releases have occurred due to this event from the unit."

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

The electric plant is in a normal lineup for current plant conditions with all emergency diesel generators available. The cause of the initial isolation of low-pressure feedwater string "A" is still under investigation.

OFFSITE NOTIFICATION - REPORT TO ANOTHER GOVERNMENT AGENCY

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

"At 2138 EST on November 18, 2023, Harris Nuclear Plant notified the National Response Center of a biodegradable oil leak that entered the Harris Lake. The North Carolina Department of Environmental Quality will also be notified of this condition on November 19, 2023. The oil leak was less than one gallon and came from a temporary pump. The leak has stopped, and spill cleanup is underway. This condition did not violate any NRC regulations or reporting criteria. This notification is being made solely as a four-hour, non-emergency notification for a notification to another government agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi).

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

FITNESS FOR DUTY REPORT

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

"On November 18, 2023, the presence of alcohol was discovered inside the protected area. In accordance with the Constellation Fitness For Duty (FFD) Program, the individual has been escorted offsite and access to the plant denied pending the results of an investigation.

"This event is being reported under 10 CFR 26.719(b)(1) as it represents a significant FFD violation.

"The NRC Resident Inspector has been notified."