Event Notification Report for December 13, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/12/2023 - 12/13/2023
Power Reactor
Event Number: 56887
Facility: River Bend
Region: 4 State: LA
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Chris Dwyer
HQ OPS Officer: Ernest West
Region: 4 State: LA
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Chris Dwyer
HQ OPS Officer: Ernest West
Notification Date: 12/13/2023
Notification Time: 05:50 [ET]
Event Date: 12/13/2023
Event Time: 01:02 [CST]
Last Update Date: 12/13/2023
Notification Time: 05:50 [ET]
Event Date: 12/13/2023
Event Time: 01:02 [CST]
Last Update Date: 12/13/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Agrawal, Ami (R4DO)
Agrawal, Ami (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 100 | Power Operation | 0 | Hot Shutdown |
AUTOMATIC REACTOR SCRAM
The following information was provided by the licensee via phone and email:
"At 0102 CST, while operating at 100 percent [reactor] power, River Bend Station experienced an automatic reactor scram caused by a turbine trip signal. The cause of the turbine trip signal is not known at this time and is being investigated. At 0108, reactor core isolation cooling (RCIC) was initiated due to a loss of reactor feed pumps following feedwater heater string isolation. At 0114, reactor water level control was transferred back to feedwater and RCIC was secured. Reactor water level is being maintained by feedwater pumps and reactor pressure is being maintained by turbine bypass valves. The scram was uncomplicated and all other plant systems responded as designed.
"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 expected post scram [reactor water] level 3 isolations and manual initiation of RCIC.
"No radiological releases have occurred due to this event from the unit.
"The NRC Senior Resident Inspector has been notified of this event."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The cause of the turbine trip, while still under investigation, was likely due to an electrical transient involving the main generator. Walkdowns in the switchyard post-scram identified damage to one of the output breaker disconnects.
The following information was provided by the licensee via phone and email:
"At 0102 CST, while operating at 100 percent [reactor] power, River Bend Station experienced an automatic reactor scram caused by a turbine trip signal. The cause of the turbine trip signal is not known at this time and is being investigated. At 0108, reactor core isolation cooling (RCIC) was initiated due to a loss of reactor feed pumps following feedwater heater string isolation. At 0114, reactor water level control was transferred back to feedwater and RCIC was secured. Reactor water level is being maintained by feedwater pumps and reactor pressure is being maintained by turbine bypass valves. The scram was uncomplicated and all other plant systems responded as designed.
"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 expected post scram [reactor water] level 3 isolations and manual initiation of RCIC.
"No radiological releases have occurred due to this event from the unit.
"The NRC Senior Resident Inspector has been notified of this event."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The cause of the turbine trip, while still under investigation, was likely due to an electrical transient involving the main generator. Walkdowns in the switchyard post-scram identified damage to one of the output breaker disconnects.
Part 21
Event Number: 56958
Rep Org: Ametek Solidstate Controls
Licensee:
Region: 0
City: State:
County:
License #:
Agreement: N
Docket:
NRC Notified By: Zach Rumora
HQ OPS Officer: Thomas Herrity
Licensee:
Region: 0
City: State:
County:
License #:
Agreement: N
Docket:
NRC Notified By: Zach Rumora
HQ OPS Officer: Thomas Herrity
Notification Date: 02/09/2024
Notification Time: 16:13 [ET]
Event Date: 12/13/2023
Event Time: 00:00 [ ]
Last Update Date: 05/17/2024
Notification Time: 16:13 [ET]
Event Date: 12/13/2023
Event Time: 00:00 [ ]
Last Update Date: 05/17/2024
Emergency Class: Non Emergency
10 CFR Section:
21.21(a)(2) - Interim Eval Of Deviation 21.21(d)(3)(i) - Defects And Noncompliance
10 CFR Section:
21.21(a)(2) - Interim Eval Of Deviation 21.21(d)(3)(i) - Defects And Noncompliance
Person (Organization):
Part 21/50.55 Reactors, - (EMAIL)
Part 21/50.55 Reactors, - (EMAIL)
EN Revision Imported Date: 5/20/2024
EN Revision Text: PART 21 - INTERIM REPORT FOR OIL FILLED CAPACITORS
The following is a synopsis of information that was provided by AMETEK Solidstate Controls Inc. via email:
This component (07-020139-10) is a 13 micro-Farad AC oil filled capacitor. During operation in an inverter, oil may be visible on, around, or dripping from the capacitor or its mounting bracket or tray. If allowed sufficient time, enough oil will leak from the capacitor that it will short internally and fail. Time required for the failure could be greater than the recommended 10-year preventative maintenance cycle for this part.
AMETEK Solidstate Controls has not been able to determine a definitive cause of the failure, but is working to do so.
These capacitors are generally part of a larger capacitor bank. The failure would result in a reduction of output voltage that is directly proportional to the number of capacitors in the bank that fail. Any single capacitor failure would be less than a 3 volt decrease in output voltage.
Users of these capacitors should visually inspect any equipment containing the capacitor part number stated above for evidence of an oil leak. A review of the output voltage for the parent equipment for any consistent decrease in voltage of 0-3V may serve as an indication of capacitor failure. The user should notify AMETEK Solidstate Controls if any oil is observed during inspection.
Corrective actions should be established by May 2024.
Affected plants are not listed.
* * * UPDATE ON 05/17/24 AT 1305 EDT FROM ZACHARY RUMORA TO KAREN COTTON * * *
FINAL REPORT FOR OIL FILLED CAPACITORS
AMETEK Solidstate Controls Inc, (SCI) has completed their evaluation of the deviation described in their interim report submitted on February 9, 2024, and concluded that there was no way of recreating the potential defect and no evidence of a broad defect with the general design, manufacture, or use of the capacitor. However, they identified hypothesized causes of the failure and corrective actions to mitigate failure risks. AMETEK SCI also identified the end users that may be potentially affected.
The affected plants are Duke Energy; Oconee and Catawba, TVA; Browns Ferry and Watts Bar; Georgia Power, Vogtle 1 and 2; Dominion; Surry; and South Texas Nuclear Operating Company.
Notified R2DO(Miller), R4DO(Josey) and Part 21/50.55 Reactors (email)
EN Revision Text: PART 21 - INTERIM REPORT FOR OIL FILLED CAPACITORS
The following is a synopsis of information that was provided by AMETEK Solidstate Controls Inc. via email:
This component (07-020139-10) is a 13 micro-Farad AC oil filled capacitor. During operation in an inverter, oil may be visible on, around, or dripping from the capacitor or its mounting bracket or tray. If allowed sufficient time, enough oil will leak from the capacitor that it will short internally and fail. Time required for the failure could be greater than the recommended 10-year preventative maintenance cycle for this part.
AMETEK Solidstate Controls has not been able to determine a definitive cause of the failure, but is working to do so.
These capacitors are generally part of a larger capacitor bank. The failure would result in a reduction of output voltage that is directly proportional to the number of capacitors in the bank that fail. Any single capacitor failure would be less than a 3 volt decrease in output voltage.
Users of these capacitors should visually inspect any equipment containing the capacitor part number stated above for evidence of an oil leak. A review of the output voltage for the parent equipment for any consistent decrease in voltage of 0-3V may serve as an indication of capacitor failure. The user should notify AMETEK Solidstate Controls if any oil is observed during inspection.
Corrective actions should be established by May 2024.
Affected plants are not listed.
* * * UPDATE ON 05/17/24 AT 1305 EDT FROM ZACHARY RUMORA TO KAREN COTTON * * *
FINAL REPORT FOR OIL FILLED CAPACITORS
AMETEK Solidstate Controls Inc, (SCI) has completed their evaluation of the deviation described in their interim report submitted on February 9, 2024, and concluded that there was no way of recreating the potential defect and no evidence of a broad defect with the general design, manufacture, or use of the capacitor. However, they identified hypothesized causes of the failure and corrective actions to mitigate failure risks. AMETEK SCI also identified the end users that may be potentially affected.
The affected plants are Duke Energy; Oconee and Catawba, TVA; Browns Ferry and Watts Bar; Georgia Power, Vogtle 1 and 2; Dominion; Surry; and South Texas Nuclear Operating Company.
Notified R2DO(Miller), R4DO(Josey) and Part 21/50.55 Reactors (email)