FRENCHTOWN TOWNSHIP -- A utility is looking into what caused an automatic shutdown of the Fermi 2 nuclear reactor in southeast Michigan near Monroe.
The Monroe Evening News reports Monday that the shutdown occurred Sunday afternoon after the main turbine stopped running.
DTE Energy officials tell the newspaper that a loss of a vacuum in the Frenchtown Township plant's main steam condenser is believed to have caused the shutdown. Safety systems operated as designed.
The reactor was running at 97 percent of its power. Reports show operators manually manipulated one of the rods controlling nuclear reaction after it did not fully insert into the core.
A DTE Energy spokesman said the reactor was to have been shut down Monday for refueling and maintenance.