Event Notification Report for October 19, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/18/2023 - 10/19/2023
Power Reactor
Event Number: 56803
Facility: Prairie Island
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: Martin Cabiro
HQ OPS Officer: Ernest West
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: Martin Cabiro
HQ OPS Officer: Ernest West
Notification Date: 10/19/2023
Notification Time: 15:15 [ET]
Event Date: 10/19/2023
Event Time: 11:10 [CDT]
Last Update Date: 10/19/2023
Notification Time: 15:15 [ET]
Event Date: 10/19/2023
Event Time: 11:10 [CDT]
Last Update Date: 10/19/2023
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):
Orth, Steve (R3DO)
Crouch, Howard (IR)
Russell Felts (NRR EO) (NRR EO)
Orth, Steve (R3DO)
Crouch, Howard (IR)
Russell Felts (NRR EO) (NRR EO)
| 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
The following information was provided by the licensee via email:
"On 10/19/2023, at approximately 1110 [CST], with Unit 1 in mode 1 at 100 percent power, the reactor automatically tripped. All control rods fully inserted into the core following the trip. All safety functions operated as designed. The cause of the trip is being investigated.
"Operations responded and stabilized the plant. Auxiliary feedwater actuated as expected. Decay heat is being removed by the steam generator through the steam generator power operated relief valve. The trip was complex as non-safety related power was lost to both Unit 1 and Unit 2. Unit 1 is currently in mode 3 and on natural recirculation as both reactor coolant pumps are without power. Unit 2 is currently in a refueling outage with all fuel in the spent fuel pool (SFP). SFP cooling was lost for approximately 70 minutes. No impacts to the SFP temperature were observed.
"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). Due to the actuation of the auxiliary feedwater system following the reactor trip, this event is being reported as a specified system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
* * * UPDATE ON 10/19/2023 AT 1646 EDT FROM MARTIN CABIRO TO ERNEST WEST * * *
The second paragraph of the original report is amended as follows to correct information regarding the spent fuel pool for Unit 2:
"Unit 2 is currently in a refueling outage with all fuel in the spent fuel pool (SFP). SFP cooling was maintained at all times with one train of SFP cooling. The second train lost power and was restarted approximately 70 minutes [after power was lost]. No impacts to the SFP temperature were observed."
Notified R3DO (Orth) and IR MOC (Crouch) and NRR EO (Felts) via email
The following information was provided by the licensee via email:
"On 10/19/2023, at approximately 1110 [CST], with Unit 1 in mode 1 at 100 percent power, the reactor automatically tripped. All control rods fully inserted into the core following the trip. All safety functions operated as designed. The cause of the trip is being investigated.
"Operations responded and stabilized the plant. Auxiliary feedwater actuated as expected. Decay heat is being removed by the steam generator through the steam generator power operated relief valve. The trip was complex as non-safety related power was lost to both Unit 1 and Unit 2. Unit 1 is currently in mode 3 and on natural recirculation as both reactor coolant pumps are without power. Unit 2 is currently in a refueling outage with all fuel in the spent fuel pool (SFP). SFP cooling was lost for approximately 70 minutes. No impacts to the SFP temperature were observed.
"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). Due to the actuation of the auxiliary feedwater system following the reactor trip, this event is being reported as a specified system actuation in accordance with the reporting criteria of 10 CFR 50.72(b)(3)(iv)(A). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
* * * UPDATE ON 10/19/2023 AT 1646 EDT FROM MARTIN CABIRO TO ERNEST WEST * * *
The second paragraph of the original report is amended as follows to correct information regarding the spent fuel pool for Unit 2:
"Unit 2 is currently in a refueling outage with all fuel in the spent fuel pool (SFP). SFP cooling was maintained at all times with one train of SFP cooling. The second train lost power and was restarted approximately 70 minutes [after power was lost]. No impacts to the SFP temperature were observed."
Notified R3DO (Orth) and IR MOC (Crouch) and NRR EO (Felts) via email
Power Reactor
Event Number: 56804
Facility: Prairie Island
Region: 3 State: MN
Unit: [1] [2] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: Brian Johnson
HQ OPS Officer: Ernest West
Region: 3 State: MN
Unit: [1] [2] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: Brian Johnson
HQ OPS Officer: Ernest West
Notification Date: 10/19/2023
Notification Time: 19:58 [ET]
Event Date: 10/19/2023
Event Time: 11:10 [CDT]
Last Update Date: 10/19/2023
Notification Time: 19:58 [ET]
Event Date: 10/19/2023
Event Time: 11:10 [CDT]
Last Update Date: 10/19/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
10 CFR Section:
50.72(b)(3)(xiii) - Loss Comm/Asmt/Response
Person (Organization):
Orth, Steve (R3DO)
Orth, Steve (R3DO)
| 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 |
| 2 | N | N | 0 | Defueled | 0 | Defueled |
LOSS OF SEISMIC MONITORING CAPABILITY
The following information was provided by the licensee via phone and email:
"Reporting due to loss of emergency preparedness capabilities. Seismic monitoring capability is non-functional due to loss of power. These monitors do not have a credited compensatory measure.
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The NRC Resident Inspector has been notified. The licensee intends to notify state and local officials.
The following information was provided by the licensee via phone and email:
"Reporting due to loss of emergency preparedness capabilities. Seismic monitoring capability is non-functional due to loss of power. These monitors do not have a credited compensatory measure.
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The NRC Resident Inspector has been notified. The licensee intends to notify state and local officials.