The DTE Energy (NYSE:DTE) Fermi 2 nuclear plant in Michigan went offline unexpectedly March 19.
The facility went offline as a result of “automatic scram due to actuation of the Reactor Protection System (RPS) function of Oscillation Power Range Monitor (OPRM) Upscale,” according to an event report filed with the Nuclear Regulatory Commission (NRC).
The event happened shortly after 7 p.m. An investigation into the cause of the event is underway.
The NRC report said that “the plant had recently transitioned to Single Loop Operation after securing the ‘A’ Reactor Recirculation Pump due to loss of normal and emergency cooling water supply.
“The lowest reactor water level was 134 inches above top of active fuel. Reactor water level is being maintained in the normal band by the Feedwater and Control Rod Drive Systems. No Safety Relief Valves (SRV) actuated. Reactor pressure is being maintained via the Main Turbine Bypass Valves and Main Condenser. Reactor Pressure Vessel Level 3 isolation occurred. No additional safety system actuations occurred. All off-site power sources were available throughout the event. The plant is currently in Mode 3 and in a stable condition,” the NRC report said.
Fermi 2 is a boiling water reactor (BWR) commissioned in the late 1980s. It is listed in GenerationHub data as having an operating capacity of 1,085 MW. The plant was operating at 70% generation when it was forced to go offline, according to NRC data.