The following information is provided as a 60-day telephone notification to the NRC in accordance with
10 CFR 50.73(a)(1) reported under
10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of the Division 3
emergency diesel generator (
DG). The event occurred on May 18, 2017, at 1115
CDT. As allowed by
10 CFR 50.73(a)(1), the notification is being made via telephone.
(a) The specific train(s) and system(s) that actuated were:
During troubleshooting of blown fuses for the Reserve Auxiliary Transformer (RAT) main feed metering and relaying circuit, the Division 3 DG automatically started as a result of a loss of power signal, the RAT feed breaker for the offsite power source opened after a 15 second time delay as a result of a degraded voltage signal, and the DG output breaker subsequently closed. The loss of voltage and degraded voltage signals were generated when maintenance technicians opened the wrong test switch in the Division 3 4160-Volt Switchgear 1E22S004.
(b) Whether each train actuation was complete or partial:
Upon receiving the simulated loss of voltage and degraded voltage signals, the Division 3 DG started and the DG breaker closed as expected. No additional actuations occurred.
(c) Whether or not the system started and functioned successfully:
Upon receiving the simulated loss of voltage and degraded voltage signals, the Division 3 DG and the DG breaker were verified to have properly functioned in response to the invalid signals.
The NRC Resident Inspector has been notified.
