"Wyoming has been a leader in energy for over a century and we hope our investment in Natrium will allow Wyoming to stay in the lead for many decades to come,” Gates said in a live-streamed speech marking the launch of the project.
The reactor will be only the second new nuclear power plant built in the United States in the last 20 years by TerraPower, which Gates founded some 15 years ago, and PacifiCorp, which is owned by Buffett's Berkshire Hathaway investment company.
"This is our fastest and clearest course to becoming carbon negative," the Wyoming governor, Mark Gordon, said.
Proponents of nuclear energy say it is a superior emissions-free technology, although critics say advanced reactors like those in Wyoming could carry higher risks than conventional ones.
The new Wyoming nuclear power plant will comprise a 345-megawatt sodium-cooled fast reactor with molten salt-based energy storage that could reach 500 MW during peak power cycles.
The project will cost about $1 billion, according to Gates, who achieved global recognition first as founder of the personal computer firm Microsoft and its ubiquitous Windows operating system before launching the Bill and Melinda Gates Foundation, which focuses on public health in the global south and has played a role in the global response to the coronavirus pandemic.