Massively is overstating it.

For Three Mile Island, the actual scale of the incident was much smaller than the concern about what it might turn into. It wasn't a Chernobyl or Fukushima scale event, not remotely.

A reactor continued operating at the Three Mile Island site for decades after the event and was only closed down in the past couple of years. What is being talked about is returning that reactor to service with a power purchase agreement from Microsoft.

There are no other nuclear power purchase agreements for data centers that I'm aware of, and absurd numbers of wind and solar power purchase agreements. I'll believe a big data center + nuclear intersection when I see it.