Fermi 2 nuclear plant back online

NEWPORT, Mich. — DTE Energy’s Fermi 2 nuclear reactor was operating at 90 percent power this week as workers continued to bring the plant back into service following an unplanned April 14 shutdown that kept the facility idle for three weeks.

Fermi Nuclear Generating Station in Frenchtown Township near Monroe, Mich. in 2014.

John Austerberry, DTE spokesman, said the startup began Saturday.

Like most restarts, the process can take several days before plants are back at full power. Fermi 2 synchronized to the regional electric grid at 5:40 p.m. Sunday, an action that typically occurs once a reactor has ascended to about 20 percent power.  

“We are continuing to conduct tests and inspections with the plant at various power levels,” Mr. Austerberry said.

The plant was shut down by automatic safety systems when a transformer malfunction was identified.

Workers repaired the transformer and a valve on the reactor recirculation system.  

“That valve was identified for repair during inspections and tests of plant systems performed during the shutdown,” Mr. Austerberry said.

The work was overseen by U.S. Nuclear Regulatory Commission inspectors.

Prema Chandrathil, NRC spokesman, has said the affected transformer is offsite and provides power to several safety and non-safety systems. The safety-related systems were powered by emergency diesel generators that were automatically activated.

Sensors detected a loss of power to pumps and a subsequent reduction in feedwater flow.

Another agency spokesman, Viktoria Mitlyng, said an NRC resident inspector went to the plant’s control room after being notified of the reactor scram and observed operators’ activities during the shutdown.

“Our inspectors have also been monitoring the plant’s corrective actions throughout the shutdown, including necessary repairs to affected equipment,” Ms. Mitlyng said, adding that the two resident inspectors will continue their normal oversight of plant activities once it’s back at full power.

The plant is in northern Monroe County, along western Lake Erie and about 30 miles north of Toledo.

Contact Tom Henry at thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.