Event Notification Report for November 29, 2021
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
11/28/2021 - 11/29/2021
Power Reactor
Event Number: 55708
Facility: Monticello
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: Jason Brevig
HQ OPS Officer: Mike Stafford
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: Jason Brevig
HQ OPS Officer: Mike Stafford
Notification Date: 01/21/2022
Notification Time: 10:25 [ET]
Event Date: 11/29/2021
Event Time: 11:28 [CST]
Last Update Date: 01/21/2022
Notification Time: 10:25 [ET]
Event Date: 11/29/2021
Event Time: 11:28 [CST]
Last Update Date: 01/21/2022
Emergency Class: Non Emergency
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
10 CFR Section:
50.73(a)(1) - Invalid Specif System Actuation
Person (Organization):
Stoedter, Karla (R3)
Stoedter, Karla (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
EN Revision Imported Date: 2/18/2022
EN Revision Text: INVALID ACTUATION OF SECONDARY CONTAINMENT RELAYS
The following information was provided by the licensee via email:
"This telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report an invalid actuation of secondary containment relays in accordance with 10 CFR 50.73(a)(2)(iv)(A).
"On November 29, 2021, the `B' Fuel Pool radiation monitor spiked high during restoration following the performance of the 0068 procedure `Spent Fuel Pool & Reactor Building Exhaust Plenum Monitor Calibration' due to cable to radiation monitor connector degradation from handling. This resulted in a Partial Primary Containment Group II isolation (gas systems), initiation of Standby Gas Treatment system, and isolation of the Reactor Building Ventilation system.
"All systems responded as designed to the actuation signal. Operations reset the Partial Primary Containment Group II isolation signal, shutdown Standby Gas Treatment System, and restored Reactor Building Ventilation system per procedures.
"At the time of the occurrence, the `A' Fuel Pool radiation monitor was reading normal at approximately 1.5 mr/hr. The `B' Fuel Pool radiation monitor spiked above the 50 mr/hr setpoint and continued to read erratically. Work was performed to clean and reconnect the connector and testing per 0068 procedure verified the condition was corrected. The `B' Fuel Pool radiation monitor returned to service.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
EN Revision Text: INVALID ACTUATION OF SECONDARY CONTAINMENT RELAYS
The following information was provided by the licensee via email:
"This telephone notification is provided in accordance with 10 CFR 50.73(a)(1) to report an invalid actuation of secondary containment relays in accordance with 10 CFR 50.73(a)(2)(iv)(A).
"On November 29, 2021, the `B' Fuel Pool radiation monitor spiked high during restoration following the performance of the 0068 procedure `Spent Fuel Pool & Reactor Building Exhaust Plenum Monitor Calibration' due to cable to radiation monitor connector degradation from handling. This resulted in a Partial Primary Containment Group II isolation (gas systems), initiation of Standby Gas Treatment system, and isolation of the Reactor Building Ventilation system.
"All systems responded as designed to the actuation signal. Operations reset the Partial Primary Containment Group II isolation signal, shutdown Standby Gas Treatment System, and restored Reactor Building Ventilation system per procedures.
"At the time of the occurrence, the `A' Fuel Pool radiation monitor was reading normal at approximately 1.5 mr/hr. The `B' Fuel Pool radiation monitor spiked above the 50 mr/hr setpoint and continued to read erratically. Work was performed to clean and reconnect the connector and testing per 0068 procedure verified the condition was corrected. The `B' Fuel Pool radiation monitor returned to service.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."
Power Reactor
Event Number: 55614
Facility: Arkansas Nuclear
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: Pete Draper
HQ OPS Officer: Karen Cotton-Gross
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: Pete Draper
HQ OPS Officer: Karen Cotton-Gross
Notification Date: 11/29/2021
Notification Time: 18:47 [ET]
Event Date: 11/29/2021
Event Time: 14:58 [CST]
Last Update Date: 11/29/2021
Notification Time: 18:47 [ET]
Event Date: 11/29/2021
Event Time: 14:58 [CST]
Last Update Date: 11/29/2021
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):
Taylor, Nick (R4)
Taylor, Nick (R4)
| 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 |
EN Revision Imported Date: 12/29/2021
EN Revision Text: AUTOMATIC REACTOR TRIP
"On November 29, 2021 at 1458 CST, Arkansas Nuclear One, Unit 1, (ANO-1) automatically tripped due to high Reactor Coolant System pressure after the 'A' Main Feedwater Pump was manually tripped due to lowering speed.
"ANO-1 is currently stable in MODE 3 (Hot Standby) maintaining pressure and temperature with the P-75 Auxiliary Feedwater pump and steaming to the Condenser.
"There are no indications of a radiological release on either unit as a result of this event.
"This report satisfies the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A) for the Reactor Protection System actuation.
"The NRC Senior Resident Inspector has been notified."
Unit 2 was not affected.
EN Revision Text: AUTOMATIC REACTOR TRIP
"On November 29, 2021 at 1458 CST, Arkansas Nuclear One, Unit 1, (ANO-1) automatically tripped due to high Reactor Coolant System pressure after the 'A' Main Feedwater Pump was manually tripped due to lowering speed.
"ANO-1 is currently stable in MODE 3 (Hot Standby) maintaining pressure and temperature with the P-75 Auxiliary Feedwater pump and steaming to the Condenser.
"There are no indications of a radiological release on either unit as a result of this event.
"This report satisfies the reporting criteria of 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A) for the Reactor Protection System actuation.
"The NRC Senior Resident Inspector has been notified."
Unit 2 was not affected.