Three Mile Island, the site of the worst nuclear accident in U.S. history, is opening up once again. Microsoft and Constellation Energy, which owns the plant, have struck a deal that will see the plant’s undamaged reactor resume operations to power Microsoft’s AI data centers.

As tech companies scramble to secure new sources of energy, Microsoft on Friday announced a 20-year deal to restart a nuclear reactor at Pennsylvania’s Three Mile Island — a facility made infamous by a partial meltdown in 1979.

The Three Mile Island nuclear plant, home of the worst nuclear accident in U.S. history, would restart under a deal in which Microsoft purchases all its power.