The Vermont Yankee nuclear plant is off line for its regular refueling outage.
Officials at the Vernon plant say operators disconnected from the New England electrical grid early Sunday morning.
The plant had been producing power for 415 consecutive days, the plant’s second longest operating run on record.
But on several occasions the plant operated at reduced output for several days because of technical problems at the facility.
While Vermont Yankee is off-line specialized contractors will perform tests and inspections throughout the plant.
The outage is expected to last several weeks.