TerraPower, Bill Gates’s energy company that SK Group invested in, is starting the construction of a next-generation nuclear power plant at its Wyoming site, SK Group said Tuesday.

According to SK Group, TerraPower held its groundbreaking ceremony Monday at Kemmerer, Wyoming, with Chairman Bill Gates, TerraPower CEO Chris Levesque, and government representatives participating. SK On Vice Chairman Yoo Jung-joon and SK Inc. Executive Vice President Kim Moo-hwan also joined the event.

Kemmerer is a town that has relied on coal for over a century. Bill Gates and TerraPower plan to build a nontraditional, sodium-cooled nuclear reactor adjacent to PacifiCorp’s Naughton Power Plant. The plant is expected to substitute the power generation of PacifiCorp’s coal-fired power plant, which is scheduled to stop burning coal and natural gas soon.

“This is a big step toward safe, abundant, zero-carbon energy,” Gates said during the groundbreaking ceremony.

The plant features a 345-megawatt sodium-cooled fast reactor with a molten salt-based energy storage system, according to TerraPower. Its output can also be boosted to 50 MW, enough to run 400,000 homes. The reactor’s coolant liquid sodium, which has a significantly higher boiling point, 882 degrees Celsius, also allows the reactor to boost its output more than conventional reactors that use water as coolant.

The construction project is expected to cost up to $4 billion, half funded by the US Department of Energy as part of the agency’s Advanced Reactor Demonstration Program.

TerraPower’s current work is to have the site ready to build the reactor as soon as the company receives a final construction permit from the Nuclear Regulatory Commission (NRC). In March, TerraPower applied for the permit with the NRC.

If TerraPower successfully receives its NRC permit and begins commercial operation of the plant, SK Group will push ahead with SMR business with TerraPower in Asia, the group said.

SK Group became TerraPower’s partner after its holding company SK Inc. and the energy business unit SK Innovation made an early investment of some $250 million in 2022. Their shares in the US power company, however, have not been disclosed.

“TerraPower is currently accelerating commercialization (of the nuclear reactor) through its old technology and partnerships with the US government and other private companies,” SK Inc. Executive Vice President Kim Moo-hwan said. “(SK Group) will partner with TerraPower to find new business opportunities in Asian countries in the future.”

SK Group expects it can increase its competitiveness in the rapidly growing SMR industry. “SMRs are smaller, cheaper and safer substitutes for conventional reactors,” an official from SK Group said. “Several countries, including the US, Korea, France, China and Russia, are speeding up their development and commercialization of SMR, whose demand is expected to continuously increase," fueled particularly by power-hungry industrial and technology companies.