TerraPower’s Natrium on schedule, fuel remains a concern

TerraPower is confident its advanced nuclear reactor Natrium will be ready on time with construction plans and licensing running smoothly, but fuel supply remains a concern, the company says.

Founded by Bill Gates, TerraPower submitted its construction permit application to the Nuclear Regulatory Commission (NRC) in March and is well on its way to deploy its first-of-a-kind advanced reactor by 2030.

Natrium, a 345 MWe sodium-cooled fast reactor with molten salt-based energy storage system, was originally projected to begin generating power in 2028, but the deadline was moved after Russia, the only commercial source of high-assay, low-enriched uranium (HALEU), invaded Ukraine in 2022.

Fuel supply remains TerraPower’s main concern for the first plant, on which the company expects to begin non-nuclear-related construction in June, Director of External Affairs at TerraPower Jeff Navin says.

Navin, who oversees TerraPower’s government affairs, public policy, communications, and stakeholder engagement efforts, said the supply of HALEU was considered the “longest pole in the tent” when planning for deployment.

“We still think 2030 is our best bet as to when we can get things completed, but I can't tell you today that I can account for every kilogram of HALEU that we will need, where it will come from, and when we'll have it, so that that is certainly something that still keeps us up at night,” Navin says.

The two winners of the U.S.'s Advanced Reactor Demonstration Program (ARDP) – X-Energy is working on the high-temperature gas reactor Xe-100 – are together expected to need around 20 tons of HALEU to start their demonstrations, due to start at aruond the same time. More will be needed within 12-18 months for refueling of the first plants.

Production plans

Plans for domestically produced fuel have been put into action, including a two-phase project to produce 900 kg of HALEU a year by the nuclear fuel and services company Centrus.

In November, the company delivered 20 kg of fuel to the U.S. government as part of phase 1 and has moved to phase 2 via an evenly-split cost sharing plan with the Department of Energy (DOE) worth $60 million.

In 2022, the Inflation Reduction Act (IRA) set aside some $700 million for the nuclear industry, with $500 million of that for HALEU production, $100 million to start a HALEU transportation system, and another $100 million for research, development, demonstration, and commercial use.

However, there have been delays.

“We're coming up on two years since the first $700 million of that was appropriated through the Inflation Reduction Act, and the program still hasn't released a single dollar. So, we are watching that very closely,” says Navin.

The government is aware of the potential bottleneck, he says.

“We feel very confident that there will be multiple enrichers making HALEU in the United States in the future. The question is how quickly they will be put in place for us to meet our initial core load for our first reactor. We just need more centrifuges spinning as quickly as possible to increase the amount of HALEU that's commercially available.”

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Regulatory hurdles

TerraPower was the first advanced nuclear company to submit its construction permit application to the NRC when it passed a more-than 3,300-page to the regulator in late March.

The application comes after hundreds of meetings and conversations with the NRC and, Navin says, the regulator has shown itself to be thoughtful, curious, and aligned toward moving forward with the process rather than trying to slow things down.

“So far, we've been very impressed with the way that the NRC has approached this and we're very confident that we will be able to get, working with them, a completed license within 30 to 36 months,” he says.

The company’s confidence that it is approaching the final straight in the race to deployment is largely shared by analysts watching the demonstration program.

The advanced reactors that form the ARDP are prompting a lot of excitement for their versatility and applications, says Senior Policy Advisor on Climate and Energy Program at think tank Third Way Ryan Norman.

“They have reason to be bullish and I think there's a lot of strong stakeholders on their side wanting to move this project forward,” says Norman.

“The fact that they feel confident enough to get the ball moving and the fact that the NRC has given them the all clear to submit that license application are great signs, especially for first-of-a-kind, non-light water technology.”

Evolution of nuclear power generation by region, 1972-2026

(Click to enlarge) 

Note: The 2026 forecast is based on projects currently under construction and expected to be operational by the end of the period.

Source: International Energy Agency Electricity 2024: Analysis and Forecast to 2026

It takes a village

In August 2023, TerraPower bought land in Kemmerer, Wyoming where the Natrium Reactor Demonstration Project would be built.

Kemmerer is a small town of just over 2,000 people and home to the Naughton coal-fired power station which is scheduled to close in 2025.

TerraPower, which expects to employ around 1,600 people for the construction phase of the Natrium plant, hopes to hire from the local population both for the initial phases and for the just over 200 workers it will need to run the plant once it is built.

“When we looked at where we wanted to cite this first reactor, the availability of half of our workforce that's trained and experienced and knows how to do this work was a really big draw,” says Navin.

The coal mine’s transmission infrastructure and access to water were also major attractions, he says.

The company signed in 2022 a memorandum of understanding (MOU) with the utility PacifiCorp to examine five other coal plants slated for retirement in the region for potential Natrium deployment.

The foundation of the Kemmerer demonstration provides a workforce and supply chain that will make each successive project easier and cheaper.

“The same crew that would pour the concrete here, or put the steel on the ground here, could drive down the road and do it again, and then do it again. The third or fourth or fifth time you do something, you have taken those learnings from the first time you did it and you can do a better job the next time,” says Navin.

The need to replace coal operations with a non-greenhouse-gas emitting alternative, or power an always-on data center, is a perfect fit for a small reactor like Natrium and, rather than seeking the substantial financial backing for a gigawatt-plant, the versatility of an SMR could help kickstart a new era of nuclear power.

Across-the-aisle government commitment to help establish the first units has been key.

“The ARDP was created not just to help build two nuclear power plants, but to really restart this industry and have the United States reap all the benefits of that domestic industry being robust again,” says Navin.

By Paul Day