Event Notification Report for October 22, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
10/21/2023 - 10/22/2023
Power Reactor
Event Number: 56810
Facility: Nine Mile Point
Region: 1 State: NY
Unit: [1] [] []
RX Type: [1] GE-2,[2] GE-5
NRC Notified By: Conor Henrie
HQ OPS Officer: John Russell
Region: 1 State: NY
Unit: [1] [] []
RX Type: [1] GE-2,[2] GE-5
NRC Notified By: Conor Henrie
HQ OPS Officer: John Russell
Notification Date: 10/22/2023
Notification Time: 01:43 [ET]
Event Date: 10/22/2023
Event Time: 20:48 [EDT]
Last Update Date: 10/22/2023
Notification Time: 01:43 [ET]
Event Date: 10/22/2023
Event Time: 20:48 [EDT]
Last Update Date: 10/22/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(A) - Pot Unable To Safe S/D
10 CFR Section:
50.72(b)(3)(v)(A) - Pot Unable To Safe S/D
Person (Organization):
Jackson, Don (R1DO)
Jackson, Don (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 |
AVERAGE POWER RANGE MONITORS DECLARED INOPERABLE
The following information was provided by the licensee via phone and email:
"On October 21, 2023, at 2048 EDT, reactor recirculation pump (RRP) 12 tripped. The cause for the trip is under investigation.
"Following the RRP trip, the average power range monitors (APRMs) flow bias trips were inoperable due to reverse flow through RRP 12. The APRMs were restored to operable on October 21, 2023, at 2058 EDT, when the RRP 12 discharge blocking valve was closed.
"This 8-hour non-emergency report is being made based upon requirements of 10CFR50.72(b)(3)(v)(A) which states: "Licensee shall notify the NRC of any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A) Shut down the reactor and maintain it in a safe shutdown condition."
"The NRC Resident Inspector has been notified."
The following information was provided by the licensee via phone and email:
"On October 21, 2023, at 2048 EDT, reactor recirculation pump (RRP) 12 tripped. The cause for the trip is under investigation.
"Following the RRP trip, the average power range monitors (APRMs) flow bias trips were inoperable due to reverse flow through RRP 12. The APRMs were restored to operable on October 21, 2023, at 2058 EDT, when the RRP 12 discharge blocking valve was closed.
"This 8-hour non-emergency report is being made based upon requirements of 10CFR50.72(b)(3)(v)(A) which states: "Licensee shall notify the NRC of any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A) Shut down the reactor and maintain it in a safe shutdown condition."
"The NRC Resident Inspector has been notified."
Power Reactor
Event Number: 56811
Facility: Cooper
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: Curtis Martin
HQ OPS Officer: Ernest West
Region: 4 State: NE
Unit: [1] [] []
RX Type: [1] GE-4
NRC Notified By: Curtis Martin
HQ OPS Officer: Ernest West
Notification Date: 10/22/2023
Notification Time: 16:40 [ET]
Event Date: 10/22/2023
Event Time: 11:49 [CDT]
Last Update Date: 10/22/2023
Notification Time: 16:40 [ET]
Event Date: 10/22/2023
Event Time: 11:49 [CDT]
Last Update Date: 10/22/2023
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(3)(v)(C) - Pot Uncntrl Rad Rel 50.72(b)(3)(v)(D) - Accident Mitigation
10 CFR Section:
50.72(b)(3)(v)(C) - Pot Uncntrl Rad Rel 50.72(b)(3)(v)(D) - Accident Mitigation
Person (Organization):
O'Keefe, Neil (R4DO)
O'Keefe, Neil (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | Y | 100 | Power Operation | 100 | Power Operation |
SECONDARY CONTAINMENT MOMENTARILY INOPERABLE
The following information was provided by the licensee via fax and phone:
"On October 22, 2023, at 1149 CDT, with the reactor at 100 percent core thermal power and steady state conditions, the Cooper Nuclear Station secondary containment differential pressure exceeded the Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1 limit of -0.25 inches water gauge. The condition existed for approximately 80 seconds until the reactor building ventilation system responded to restore differential pressure to normal. Investigations identified a hinged duct access hatch found open. The hatch was closed and latched, and ventilation system parameters were returned to normal. There were no radiological releases associated with this event.
"Declaring secondary containment inoperable as a result of not meeting TS SR 3.6.4.1.1 is reportable under 10 CFR 50.72(b)(3)(v)(C) and (D) as an event or condition that could have prevented the fulfillment of a safety function needed to control the release of radioactive material and mitigate the consequences of an accident.
"The NRC Senior Resident Inspector has been informed."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
At the time the licensee notified the NRC Headquarters Operations Officer, the cause of the hinged access duct being open had not been determined. This event has been added to the licensee's corrective action program.
The following information was provided by the licensee via fax and phone:
"On October 22, 2023, at 1149 CDT, with the reactor at 100 percent core thermal power and steady state conditions, the Cooper Nuclear Station secondary containment differential pressure exceeded the Technical Specification (TS) Surveillance Requirement (SR) 3.6.4.1.1 limit of -0.25 inches water gauge. The condition existed for approximately 80 seconds until the reactor building ventilation system responded to restore differential pressure to normal. Investigations identified a hinged duct access hatch found open. The hatch was closed and latched, and ventilation system parameters were returned to normal. There were no radiological releases associated with this event.
"Declaring secondary containment inoperable as a result of not meeting TS SR 3.6.4.1.1 is reportable under 10 CFR 50.72(b)(3)(v)(C) and (D) as an event or condition that could have prevented the fulfillment of a safety function needed to control the release of radioactive material and mitigate the consequences of an accident.
"The NRC Senior Resident Inspector has been informed."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
At the time the licensee notified the NRC Headquarters Operations Officer, the cause of the hinged access duct being open had not been determined. This event has been added to the licensee's corrective action program.