Meanwhile, the decommissioning of the Unit 2 reactor, damaged in what was the worst nuclear accident in U.S. history in March 1979, continues. More: TMI's owner prepares to ask permission to ...

TMI to restart Unit 1, state officials respond Officials with Constellation Energy announced plans to restart Three Mile Island Unit, part of a 20-year power purchase agreement with Microsoft.

More: Activist urges York County commissioners to help block the restart of TMI's Unit 1 reactor A boat makes its way past the towers of Three Mile Island in 2017.