Amazon said Monday that it will spend $20 billion on two data center complexes in Pennsylvania, including one it is building alongside a nuclear power plant that has drawn federal scrutiny over an arrangement to essentially plug right into the power plant.

The majority owner of the Susquehanna nuclear power plant, Talen Energy, announced last year that it had sold its data center to Amazon for $650 million in a deal to eventually provide 960 megawatts. That’s 40% of the output of one of the nation’s largest nuclear power plants, or enough to power more than a half-million homes.

One data center is being built next to northeastern Pennsylvania’s Susquehanna nuclear power plant. The other will be in Fairless Hills at a logistics campus, the Keystone Trade Center, on what was once a U.