They're looking to a new generation of small modular reactors, while Microsoft has its own nuclear plans tied to the Three Mile Island plant.

Companies that own nuclear reactors have been the biggest beneficiaries of rising demand for nuclear power for most of this year. That includes Constellation Energy and Vistra, whose stocks have more than doubled this year.

Amazon has a deal with Energy Northwest to fund the initial feasibility phase of a nuclear facility in central Washington, with the right to purchase electricity from the 320 megawatt plant.