The U.S. Nuclear Regulatory Commission on Wednesday approved its first construction permit for a commercial nuclear reactor in eight years, one that will allow a Bill Gates-backed company to build a sodium-cooled reactor in western Wyoming.

TerraPower filed for the permit in 2024 and construction is now set to begin within weeks. Completion of the up to $4 billion plant is targeted for 2030, according to TerraPower. Microsoft co-founder Gates, who is eyeing nuclear generation as a power source for the electricity-hungry data centers behind artificial intelligence, is a founder of TerraPower and its primary investor.

“We have spent thousands of manpower hours working to achieve this momentous accomplishment,” TerraPower President and CEO Chris Levesque said in a statement.

The TerraPower plant is set to be built near a coal-fired power plant that is being converted to burn natural gas outside Kemmerer, a town of about 2,500 people some 130 miles northeast of Salt Lake City.

Gates and his energy company are seeking to develop a next-generation nuclear plant that would “revolutionize” how power is generated. The 345-megawatt reactor is expected to produce up to 500 megawatts at its peak, enough energy for up to 400,000 homes.

Construction at the TerraPower plant site — though not on the reactor itself — began in 2024.

The reactor construction permit for a TerraPower subsidiary is the NRC’s first approval for a non-light-water commercial reactor in more than 40 years, the NRC said in a statement.

Virtually all of the world’s commercial nuclear reactors use water to control reactions and transfer heat to drive turbines and produce electricity.

The NRC last issued a construction permit for a conventional light-water reactor to Florida Power & Light Company for a power plant south of Miami in 2018. That project has yet to be built.

The TerraPower reactor would use molten sodium, not water, as a coolant.

The last commercial non-light-water reactor in operation in the U.S. was the Fort St. Vrain nuclear plant in northern Colorado. The problem-plagued, helium-cooled plant produced electricity from the mid-1970s until it was shut down in 1989.

In October, Gates told reporters he thinks nuclear power will be a “gigantic contributor” to powering data centers. He had recently met with Energy Secretary Chris Wright, Interior Secretary Doug Burgum and various members of Congress and said the government was “very involved” in the TerraPower reactor.

“I wish I could deliver nuclear fission like three years earlier than I can, because then we’d have a perfect match to the current demand pattern of these data center guys,” he said.