Event Notification Report for August 06, 2022
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/05/2022 - 08/06/2022
EVENT NUMBERS
56138
56138
Power Reactor
Event Number: 56138
Facility: Brunswick
Region: 2 State: NC
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Jacob Cottle
HQ OPS Officer: Howie Crouch
Region: 2 State: NC
Unit: [2] [] []
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: Jacob Cottle
HQ OPS Officer: Howie Crouch
Notification Date: 10/04/2022
Notification Time: 10:27 [ET]
Event Date: 08/06/2022
Event Time: 06:28 [EDT]
Last Update Date: 10/04/2022
Notification Time: 10:27 [ET]
Event Date: 08/06/2022
Event Time: 06:28 [EDT]
Last Update Date: 10/04/2022
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):
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 |
60-DAY OPTIONAL TELEPHONIC NOTIFICATION OF INVALID ACTUATION OF CONTAINMENT ISOLATION VALVES
The following information was provided by the licensee via email:
"This 60-day optional telephone notification is being made in lieu of an 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 invalid actuations of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).
"At approximately 0628 Eastern Daylight Time (EDT) on August 6, 2022, an invalid actuation of group 6 Primary Containment Isolation Valves (PCIVs) (i.e., containment atmospheric control/monitoring and post accident sampling isolation valves) occurred. The group 6 isolation signal resulted from the reactor building ventilation radiation monitor `A' channel exceeding the setpoint value. This condition recurred at approximately 1305 EDT on August 12, 2022. In both instances, the `B' channel, located in the same plenum, remained steady and below the setpoint value through the entire event. This, along with readings made by radiation protection technicians, confirmed that there were no actual high radiation conditions in the reactor building exhaust in either instance. Following each invalid actuation, upon returning unit 2 reactor building ventilation to service, the `A' channel readings returned to be consistent with the `B' channel. It was determined that these invalid actuations likely resulted from degradation of circuit components associated with the radiation monitor. The `A' channel radiation monitor was replaced on September 22, 2022.
"During these two events, the PCIVs functioned successfully and the actuations were complete. The actuations were not initiated in response to actual plant conditions, they were not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, these events have been determined to be invalid actuations.
"These events did not result in any adverse impact to the health and safety of the public."
The following information was provided by the licensee via email:
"This 60-day optional telephone notification is being made in lieu of an 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 invalid actuations of one of the systems listed in 10 CFR 50.73(a)(2)(iv)(B).
"At approximately 0628 Eastern Daylight Time (EDT) on August 6, 2022, an invalid actuation of group 6 Primary Containment Isolation Valves (PCIVs) (i.e., containment atmospheric control/monitoring and post accident sampling isolation valves) occurred. The group 6 isolation signal resulted from the reactor building ventilation radiation monitor `A' channel exceeding the setpoint value. This condition recurred at approximately 1305 EDT on August 12, 2022. In both instances, the `B' channel, located in the same plenum, remained steady and below the setpoint value through the entire event. This, along with readings made by radiation protection technicians, confirmed that there were no actual high radiation conditions in the reactor building exhaust in either instance. Following each invalid actuation, upon returning unit 2 reactor building ventilation to service, the `A' channel readings returned to be consistent with the `B' channel. It was determined that these invalid actuations likely resulted from degradation of circuit components associated with the radiation monitor. The `A' channel radiation monitor was replaced on September 22, 2022.
"During these two events, the PCIVs functioned successfully and the actuations were complete. The actuations were not initiated in response to actual plant conditions, they were not an intentional manual initiation, and there were no parameters satisfying the requirements for initiation of the system. Therefore, these events have been determined to be invalid actuations.
"These events did not result in any adverse impact to the health and safety of the public."