| ENS 57387 | Brunswick | 10 September 2024 17:42:00 | 60-DAY Optional Telephonic Notification of 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 1342 EDT, on September 10, 2024, the reactor water cleanup (RWCU) inboard primary containment isolation valve (PCIV), and the reactor recirculation pump sample inboard PCIV, unexpectedly closed. At the time of this event, work was in progress replacing a control relay in the residual heat removal (RHR) shutdown cooling inboard isolation PCIV circuitry. This relay replacement required lifting the leads of several wires. The neutral side of the relay was electrically connected with the actuation logic for the inboard RWCU and reactor recirculation pump sample PCIVs; the lifting of this lead resulted in the unexpected closure of these PCIVs.
The actuation was not initiated in response to actual plant conditions, nor 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 was notified.
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Unit 2 was not affected. |