A plan by Microsoft to use the restart of a Three Mile Island nuclear reactor to help power its expanding data centers reflects the tech industry's hopes nuclear energy can be a quick and climate-friendly answer to its massive electricity needs.

Two American energy companies are each preparing to bring a nuclear power station back into service, an unprecedented operation which should help meet the growing need for electricity in the United States.

The question just became concrete, after Microsoft announced last week that it had signed a deal that will reactivate a unit of the Three Mile Island nuclear plant in Pennsylvania. Three Mile Island became shorthand for the worst case scenario of nuclear energy,