TerraPower officially began construction of on the Natrium Nuclear Power Plant on Wednesday, April 22. Crews began excavation work at the site of Kemmerer Unit 1, the flagship plant that is set to be the first utility-scale advanced nuclear power plant in the United States. The construction process began in less than two months after receiving official approval from the Nuclear Regulator Commission (NRC) in early March.

“This is the moment our industry has been working toward for a generation. We’re not just breaking new ground on a first-of-a-kind nuclear plant in Wyoming; we’re building the next generation of America’s energy infrastructure,” said Chris Levesque, president and CEO of TerraPower. “The Natrium plant will deliver reliable and dispatchable power to the grid and Kemmerer Unit 1 serve as a commercial blueprint to mobilize a fleet of Natrium plants across the country and around the world.”

With this milestone, TerraPower is mobilizing a workforce of roughly 1,600 workers to begin plant construction, bringing the first Natrium reactor and energy storage system one step closer to fruition. Once operational, it is expected to employ approximately 250 full-time staff.

The plant features a 345-megawatt (MW) sodium-cooled fast reactor with an integrated molten salt-based energy storage system. The storage technology can boost energy output to 500 MW of power when needed, equivalent to the amount of energy needed to power around 400,000 homes. The energy storage capability is designed to keep base output steady, ensuring constant reliability, and can quickly ramp up when demand peaks. It is the only advanced reactor design with this unique feature.

“The start of construction on TerraPower’s Natrium plant in Kemmerer marks a major milestone not just for Wyoming, but for the future of American energy,” said Wyoming Governor Mark Gordon. “I want to thank everyone at Terra Power for their work getting to this day. Wyoming has long powered this country, and today we are leading again, this time in next-generation nuclear technology. This project reflects our commitment to reliable energy, good-paying jobs, and a future built on innovation and Wyoming values.”

“The United States needs more reliable baseload power now. Wyoming’s energy workers continue to lead the way,” said U.S. Senator John Barrasso. “As the country’s number one producer of uranium, Wyoming is the perfect place to build TerraPower’s advanced nuclear reactor. Starting construction on this groundbreaking project will create more jobs in Kemmerer and help expand Wyoming’s already strong energy economy. It’s a win-win for Wyoming and America’s energy security.”

“Wyoming has always powered America, and today that proud tradition reaches an exciting new milestone,” said U.S. Senator Cynthia Lummis. “The start of construction on TerraPower’s energy island in Kemmerer is a defining moment for our state, our nation, and the future of American energy. This project delivers what Wyoming communities deserve: good-paying jobs, lasting economic strength, and reliable, affordable baseload power. I am proud to stand with TerraPower, with our workers in Lincoln County, and with an Administration that is getting real results for Wyoming and American energy independence.”

“This construction of the first new state-of-the-art advanced nuclear power plant demonstrates Wyoming’s leadership pioneering a new frontier in American energy,” said U.S. Representative Harriet Hageman. “As the nation’s top producer of uranium, Wyoming is a natural launch pad for America’s nuclear renaissance.”

“Today’s construction milestone is a testament to the Department of Energy’s investment in American innovation and helping companies like TerraPower deliver the next generation of advanced nuclear technologies,” said Dr. Rian Bahran, Deputy Assistant Secretary for the U.S. Department of Energy’s Office of Nuclear Energy. “The Natrium reactor shows that when government and private industry work together, we can build a bright future for our country powered by nuclear.”

“Bechtel is proud to partner with TerraPower as the engineering, procurement and construction contractor on the Natrium advanced reactor,” said Dena Volovar, president of Bechtel’s Nuclear, Security & Environmental business. “The start of construction at Kemmerer Unit 1 marks an important step forward for the project and for the next generation of U.S. nuclear energy. By combining TerraPower’s reactor innovation with Bechtel’s processes, experience and execution model we will deliver these nuclear projects consistently, safely and at scale. By applying the latest digital tools and project delivery systems, Bechtel is uniquely positioned to deliver the nation’s first Natrium plant
with efficiency and execution certainty.”

“Rocky Mountain Power supports a balanced, all-of-the-above energy strategy,” said Dick Garlish, president of Rocky Mountain Power. “Baseload power is critical to serve our customers, and advanced nuclear technologies like the Natrium project is a promising resource.”

This first Natrium plant is being developed through the U.S. Department of Energy’s Advanced Reactor Demonstration Program (ARDP), a public-private partnership. When complete, the project will be the first utility-scale advanced nuclear power plant in the U.S. and Wyoming’s first-ever commercial nuclear generating station. The project has been under active development since TerraPower broke ground on the greenfield site in June 2024 and began construction on non-nuclear support facilities. TerraPower is rapidly commercializing the Natrium technology; which includes an agreement with Meta for up to eight Natrium plants by 2035.