Event Notification Report for April 11, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/10/2023 - 04/11/2023
Power Reactor
Event Number: 56459
Facility: Palo Verde
Region: 4 State: AZ
Unit: [1] [] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: Yolanda Good
HQ OPS Officer: Donald Norwood
Region: 4 State: AZ
Unit: [1] [] []
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: Yolanda Good
HQ OPS Officer: Donald Norwood
Notification Date: 04/09/2023
Notification Time: 04:42 [ET]
Event Date: 04/08/2023
Event Time: 21:44 [MST]
Last Update Date: 04/09/2023
Notification Time: 04:42 [ET]
Event Date: 04/08/2023
Event Time: 21:44 [MST]
Last Update Date: 04/09/2023
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):
Warnick, Greg (R4DO)
Warnick, Greg (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 Standby |
AUTOMATIC REACTOR TRIP DUE TO LOSS OF REACTOR COOLANT PUMPS
The following information was provided by the licensee via email:
"The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10 CFR 50.73.
"At 2144 MST on April 8, 2023, the Unit 1 reactor automatically tripped due to the loss of reactor coolant pumps stemming from the loss of 13.8 kV power to the pumps.
"Prior to the reactor trip, the main turbine tripped due to a loss of hydraulic pressure. The main generator output breakers did not automatically open on the turbine trip as expected so the control room operators opened the breakers per procedural guidance. Once the breakers were opened, the two 13.8 kV electrical distribution buses failed to complete a fast bus transfer, which resulted in the loss of power to the reactor coolant pumps, initiating the reactor trip. The control room operators manually actuated a main steam isolation signal per procedure, requiring use of the atmospheric dump valves.
"Following the reactor trip, all control element assemblies inserted fully into the core. No automatic specified system actuation was required or occurred. No emergency plan classification was required per the Emergency Plan. Safety related buses remained powered from offsite power during the event and the offsite power grid is stable. Unit 1 is stable and in Mode 3. Decay heat is being removed by the atmospheric dump valves and the class 1E powered motor driven auxiliary feedwater pump.
"The loss of hydraulic pressure, the main generator output breakers failing to automatically open and the fast bus transfer not actuating are being investigated.
"This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B).
"The NRC Senior Resident Inspector has been informed.
"Unit 2 is in a refueling outage in Mode 5 and Unit 3 is in Mode 1 at 100 percent power."
* * * UPDATE ON 4/9/23 AT 0835 EDT FROM TANNER GOODMAN TO ADAM KOZIOL * * *
"This update is being made to report the manual actuation of the B-train auxiliary feedwater pump and manual main steam isolation signal (MSIS) actuation affecting multiple main steam isolation valves (MSIVs) following the reactor trip.
"This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and a specified system actuation in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"The NRC Senior Resident Inspector has been informed of the update."
The following information was provided by the licensee via email:
"The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10 CFR 50.73.
"At 2144 MST on April 8, 2023, the Unit 1 reactor automatically tripped due to the loss of reactor coolant pumps stemming from the loss of 13.8 kV power to the pumps.
"Prior to the reactor trip, the main turbine tripped due to a loss of hydraulic pressure. The main generator output breakers did not automatically open on the turbine trip as expected so the control room operators opened the breakers per procedural guidance. Once the breakers were opened, the two 13.8 kV electrical distribution buses failed to complete a fast bus transfer, which resulted in the loss of power to the reactor coolant pumps, initiating the reactor trip. The control room operators manually actuated a main steam isolation signal per procedure, requiring use of the atmospheric dump valves.
"Following the reactor trip, all control element assemblies inserted fully into the core. No automatic specified system actuation was required or occurred. No emergency plan classification was required per the Emergency Plan. Safety related buses remained powered from offsite power during the event and the offsite power grid is stable. Unit 1 is stable and in Mode 3. Decay heat is being removed by the atmospheric dump valves and the class 1E powered motor driven auxiliary feedwater pump.
"The loss of hydraulic pressure, the main generator output breakers failing to automatically open and the fast bus transfer not actuating are being investigated.
"This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B).
"The NRC Senior Resident Inspector has been informed.
"Unit 2 is in a refueling outage in Mode 5 and Unit 3 is in Mode 1 at 100 percent power."
* * * UPDATE ON 4/9/23 AT 0835 EDT FROM TANNER GOODMAN TO ADAM KOZIOL * * *
"This update is being made to report the manual actuation of the B-train auxiliary feedwater pump and manual main steam isolation signal (MSIS) actuation affecting multiple main steam isolation valves (MSIVs) following the reactor trip.
"This event is being reported as a reactor protection system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and a specified system actuation in accordance with 10 CFR 50.72(b)(3)(iv)(A).
"The NRC Senior Resident Inspector has been informed of the update."
Power Reactor
Event Number: 56460
Facility: Vogtle 3/4
Region: 2 State: GA
Unit: [3] [] []
RX Type: [3] W-AP1000,[4] W-AP1000
NRC Notified By: Tommie Sweat
HQ OPS Officer: Adam Koziol
Region: 2 State: GA
Unit: [3] [] []
RX Type: [3] W-AP1000,[4] W-AP1000
NRC Notified By: Tommie Sweat
HQ OPS Officer: Adam Koziol
Notification Date: 04/10/2023
Notification Time: 04:34 [ET]
Event Date: 04/10/2023
Event Time: 00:48 [EDT]
Last Update Date: 04/10/2023
Notification Time: 04:34 [ET]
Event Date: 04/10/2023
Event Time: 00:48 [EDT]
Last Update Date: 04/10/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical
Person (Organization):
Miller, Mark (R2DO)
Miller, Mark (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 3 | A/R | Y | 18 | Power Operation | 0 | Hot Standby |
AUTOMATIC REACTOR TRIP
The following information was provided by the licensee via email:
"At 0048 EDT on 4/10/2023, with Unit 3 in Mode 1 at 18 percent power, the reactor automatically tripped due to low reactor coolant flow due to voltage decaying to the reactor coolant pumps during main generator testing activities. The trip was not complex, with all safety-related systems responding normally post-trip.
"Operations responded and stabilized the plant. Decay heat is being removed by discharging steam via steam generator power operated relief valves to atmosphere. Units 1, 2, and 4 are 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).
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
The following information was provided by the licensee via email:
"At 0048 EDT on 4/10/2023, with Unit 3 in Mode 1 at 18 percent power, the reactor automatically tripped due to low reactor coolant flow due to voltage decaying to the reactor coolant pumps during main generator testing activities. The trip was not complex, with all safety-related systems responding normally post-trip.
"Operations responded and stabilized the plant. Decay heat is being removed by discharging steam via steam generator power operated relief valves to atmosphere. Units 1, 2, and 4 are 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).
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
Agreement State
Event Number: 56454
Rep Org: Kentucky Dept of Radiation Control
Licensee: Big Rivers Electric Corporation
Region: 1
City: Centertown State: KY
County: Ohio
License #: 201-277-56
Agreement: Y
Docket:
NRC Notified By: Dr. Curt Pendergrass
HQ OPS Officer: Dan Livermore
Licensee: Big Rivers Electric Corporation
Region: 1
City: Centertown State: KY
County: Ohio
License #: 201-277-56
Agreement: Y
Docket:
NRC Notified By: Dr. Curt Pendergrass
HQ OPS Officer: Dan Livermore
Notification Date: 04/05/2023
Notification Time: 11:51 [ET]
Event Date: 04/04/2023
Event Time: 00:00 [CDT]
Last Update Date: 04/06/2023
Notification Time: 11:51 [ET]
Event Date: 04/04/2023
Event Time: 00:00 [CDT]
Last Update Date: 04/06/2023
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
Gray, Mel (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Gray, Mel (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
AGREEMENT STATE REPORT - STUCK SHUTTER
The following is a summary of information provided by the Kentucky Department of Radiation Control via email:
On April 4, 2023, an authorized gauge user identified a shutter stuck open on a gauge mounted 15 feet up in the air on a coal feeder at the D.B. Wilson power plant. The shutter opened and closed; however, when the shutter was placed into a closed position some radiation exposure was still present outside the shutter. The gauge is model number 7062BP, serial number 17777, with 100 mCi Cs-137. The Radiation Safety Officer (RSO) alerted employees of the stuck shutter. The gauge will remain in place until a certified contractor can remove it. The contractor is expected to arrive on April 5, 2023.
* * * UPDATE ON 4/6/2023 AT 1254 EDT FROM CURT PENDERGRASS TO IAN HOWARD * * *
The following information was provided by the Kentucky Department of Radiation Control via email:
"According to the RSO, RAM Services, Inc. was able to free up the shutter yesterday, but there were issues with elevated exposure rates so the decision was made to dispose of the device and package it for shipping."
Notified R1DO (Gray) and NMSS Events Notification.
The following is a summary of information provided by the Kentucky Department of Radiation Control via email:
On April 4, 2023, an authorized gauge user identified a shutter stuck open on a gauge mounted 15 feet up in the air on a coal feeder at the D.B. Wilson power plant. The shutter opened and closed; however, when the shutter was placed into a closed position some radiation exposure was still present outside the shutter. The gauge is model number 7062BP, serial number 17777, with 100 mCi Cs-137. The Radiation Safety Officer (RSO) alerted employees of the stuck shutter. The gauge will remain in place until a certified contractor can remove it. The contractor is expected to arrive on April 5, 2023.
* * * UPDATE ON 4/6/2023 AT 1254 EDT FROM CURT PENDERGRASS TO IAN HOWARD * * *
The following information was provided by the Kentucky Department of Radiation Control via email:
"According to the RSO, RAM Services, Inc. was able to free up the shutter yesterday, but there were issues with elevated exposure rates so the decision was made to dispose of the device and package it for shipping."
Notified R1DO (Gray) and NMSS Events Notification.
Power Reactor
Event Number: 56464
Facility: Limerick
Region: 1 State: PA
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Tim Gallacher
HQ OPS Officer: Sam Colvard
Region: 1 State: PA
Unit: [1] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Tim Gallacher
HQ OPS Officer: Sam Colvard
Notification Date: 04/11/2023
Notification Time: 11:05 [ET]
Event Date: 02/16/2023
Event Time: 08:05 [EDT]
Last Update Date: 04/11/2023
Notification Time: 11:05 [ET]
Event Date: 02/16/2023
Event Time: 08:05 [EDT]
Last Update Date: 04/11/2023
Emergency Class: Non Emergency
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation Other Unspec Reqmnt
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation Other Unspec Reqmnt
Person (Organization):
Lilliendahl, Jon (R1DO)
Lilliendahl, Jon (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
60 DAY NOTIFICATION FOR AN INVALID ACTUATION OF THE EMERGENCY SERVICE WATER SYSTEM
The following information was provided by the licensee via email:
"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid specific system actuation of the Emergency Service Water (ESW) System.
"On 2/16/2023, while performing a calibration planned maintenance (PM) for a jacket water pressure indicator during a D13 diesel generator system outage window, the 'C' ESW pump unexpectedly auto-started. Subsequent investigation identified that the affected jacket water pressure indicator shares a common sensing line with a jacket water pressure switch that provides a back-up to the engine speed switch for the engine running signal. At the time the jacket water pressure indicator calibration PM was being performed, the power circuits for D13 diesel generator instrumentation were energized. Pressurization of the energized jacket water pressure switch during the pressure indicator calibration activity resulted in initiation of a false engine running signal to the `C' ESW pump start logic.
"This event is considered an invalid system actuation because the 'C' ESW pump started in response to a false signal that the D13 EDG was running when the D13 EDG did not start. The actuation was not initiated in response to actual plant conditions or parameters and was not a manual initiation. The ESW system functioned as expected in response to the actuation. The affected ESW pump was shut down in accordance with plant procedures. There was no impact on the health and safety of the public or plant personnel."
The licensee notified the NRC Resident Inspector.
The following information was provided by the licensee via email:
"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid specific system actuation of the Emergency Service Water (ESW) System.
"On 2/16/2023, while performing a calibration planned maintenance (PM) for a jacket water pressure indicator during a D13 diesel generator system outage window, the 'C' ESW pump unexpectedly auto-started. Subsequent investigation identified that the affected jacket water pressure indicator shares a common sensing line with a jacket water pressure switch that provides a back-up to the engine speed switch for the engine running signal. At the time the jacket water pressure indicator calibration PM was being performed, the power circuits for D13 diesel generator instrumentation were energized. Pressurization of the energized jacket water pressure switch during the pressure indicator calibration activity resulted in initiation of a false engine running signal to the `C' ESW pump start logic.
"This event is considered an invalid system actuation because the 'C' ESW pump started in response to a false signal that the D13 EDG was running when the D13 EDG did not start. The actuation was not initiated in response to actual plant conditions or parameters and was not a manual initiation. The ESW system functioned as expected in response to the actuation. The affected ESW pump was shut down in accordance with plant procedures. There was no impact on the health and safety of the public or plant personnel."
The licensee notified the NRC Resident Inspector.