The three-day trial in US District Court in Brattleboro will weigh Entergy’s contention that the state is improperly trying to close Vermont Yankee because of safety concerns. Federal law says states have no say over nuclear safety, which is solely the province of the federal Nuclear Regulatory Commission.

The state maintains it has other reasons for wanting to close Vermont Yankee, and that it should have the right to deny the plant a state certificate of public good to keep operating.