Event Notification Report for January 01, 2024
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/31/2023 - 01/01/2024
EVENT NUMBERS
56987
56987
Power Reactor
Event Number: 56987
Facility: Brunswick
Region: 2 State: NC
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Chris Denton
HQ OPS Officer: Ernest West
Region: 2 State: NC
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Chris Denton
HQ OPS Officer: Ernest West
Notification Date: 02/22/2024
Notification Time: 08:55 [ET]
Event Date: 01/01/2024
Event Time: 23:33 [EST]
Last Update Date: 03/11/2024
Notification Time: 08:55 [ET]
Event Date: 01/01/2024
Event Time: 23:33 [EST]
Last Update Date: 03/11/2024
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):
Miller, Mark (R2DO)
Miller, Mark (R2DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 100 | Power Operation | 100 | Power Operation |
EN Revision Imported Date: 3/12/2024
EN Revision Text: INVALID ACTUATION OF CONTAINMENT ISOLATION VALVES
The following information was provided by the licensee via phone and email:
"This 60-day optional telephone notification is being made in lieu of a Licensee Event Report (LER) submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).
"At approximately 2333 EST on January 1, 2024, an invalid actuation of group 6 primary containment isolation valves (PCIVs) (i.e., containment atmospheric control/monitoring (CAC/CAM) and post-accident sampling system (PASS) isolation valves) occurred. Reactor building ventilation isolated and standby gas treatment started per design. No manipulations associated with the isolation or reset logic were ongoing at the time.
"Troubleshooting determined that the group 6 isolation signal resulted from spurious relay contact actuation in the main stack radiation high-high isolation logic due to relay contact oxidation. The main stack radiation monitor is a shared component that sends isolation signals to Unit 1 and Unit 2. There were no Unit 1 actuations. Only the relay contacts associated with Unit 2 actuated. The relay has been replaced.
"The actuation was not initiated in response to actual plant conditions. It was not an intentional manual initiation and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation.
"During this event the PCIVs functioned successfully, and the actuations were complete. This event did not result in any adverse impact to the health and safety of the public."
The NRC Resident Inspector had been notified.
EN Revision Text: INVALID ACTUATION OF CONTAINMENT ISOLATION VALVES
The following information was provided by the licensee via phone and email:
"This 60-day optional telephone notification is being made in lieu of a Licensee Event Report (LER) submittal as allowed by 10 CFR 50.73(a)(1). This notification is made pursuant to the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).
"At approximately 2333 EST on January 1, 2024, an invalid actuation of group 6 primary containment isolation valves (PCIVs) (i.e., containment atmospheric control/monitoring (CAC/CAM) and post-accident sampling system (PASS) isolation valves) occurred. Reactor building ventilation isolated and standby gas treatment started per design. No manipulations associated with the isolation or reset logic were ongoing at the time.
"Troubleshooting determined that the group 6 isolation signal resulted from spurious relay contact actuation in the main stack radiation high-high isolation logic due to relay contact oxidation. The main stack radiation monitor is a shared component that sends isolation signals to Unit 1 and Unit 2. There were no Unit 1 actuations. Only the relay contacts associated with Unit 2 actuated. The relay has been replaced.
"The actuation was not initiated in response to actual plant conditions. It was not an intentional manual initiation and there were no parameters satisfying the requirements for initiation of the system. Therefore, this event has been determined to be an invalid actuation.
"During this event the PCIVs functioned successfully, and the actuations were complete. This event did not result in any adverse impact to the health and safety of the public."
The NRC Resident Inspector had been notified.