(FILES) The Three Mile Island nuclear plant on March 28, 1979, south of Middletown, Pennsylvania. The plant, site of the worst nuclear accident in US history, is to restart operations in a deal to sell power to Microsoft, Constellation Energy said on September 20, 2024. The firm announced the 20-year deal would involve the restart of the Unit 1 reactor, "which operated at industry-leading levels of safety and reliability for decades before being shut down for economic reasons exactly five years ago today." The Unit 1 reactor was not involved in the March 28, 1979, partial nuclear meltdown. (Photo by AFP) (Photo by -/AFP via Getty Images)