TerraPower, Centrus, and Duke Energy talk tech and collaboration

September 23, 2020, 3:01PMNuclear News

Three companies that are part of a larger collaboration to develop and demonstrate Natrium, the fast reactor design recently introduced by TerraPower and GE Hitachi Nuclear Energy (GEH), were invited to participate in a webinar hosted by ClearPath to talk about Natrium’s design, fuel requirements, and load-following potential.

The September 21 webinar, titled “Natrium: Latin for Sodium, Big for Advanced Nuclear,” was moderated by Rich Powell, executive director of ClearPath, and featured TerraPower’s Chris Levesque and Tara Neider, Centrus Energy’s Dan Poneman, and Duke Energy’s Chris Nolan.

An artist’s rendering of Natrium. Image: TerraPower

About Natrium: Natrium offers baseload electricity output from a 345-MWe sodium fast reactor with the load-following flexibility of molten salt thermal storage that can be used to ramp system output up to 500 MWe for more than five and a half hours during peak demand. Nonnuclear mechanical, electrical, and other equipment would be housed at a distance from the 16-acre reactor island and could be built to industrial standards rather than nuclear standards, reducing costs. Natrium is designed to integrate into power grids with high penetrations of renewables, and it has the attention of at least two experienced nuclear operators, Duke Energy and Energy Northwest.

To fuel Natrium with high-assay, low-enriched uranium (HALEU), enriched to between 5 and 19.75 percent fissile U-235, TerraPower announced on September 15 that it plans to work with Centrus Energy to establish commercial-scale HALEU production facilities and a new Category II metal fuel fabrication facility. Centrus is currently working under a three-year, $115-million cost-shared contract with the Department of Energy to deploy 16 of its AC-100M centrifuges to demonstrate HALEU production and has applied to the Nuclear Regulatory Commission for a license to produce HALEU.

TerraPower, GE Hitachi, and Bechtel have submitted a proposal based on Natrium technology for the DOE’s Advanced Reactor Demonstration Program (ARDP). TerraPower’s investment with Centrus is also part of that proposal.

Levesque, Nolan, Poneman, and Neider offered insights into Natrium’s design and the collaborative process behind it.


Chris Levesque: The president and chief executive officer of TerraPower talked about the company’s experience with sodium fast reactors, which goes back 14 years, and its partnership with GE Hitachi that began in 2019.

“As we came together with GE Hitachi early last year, we felt a lot of synergy. . . . We brought together the best of the best between [TerraPower’s Traveling Wave Reactor] and [GEH’s] Prism.

“We did some thinking and some listening to what the utilities were saying to us about 2030 needs, and that’s where energy storage has come in. We think it’s good news that wind and solar are continuing to grow in their presence on the grid; they’re clean. . . . But we’re really seeing a problem that the U.S. has never seen before, which is managing the intermittency of wind and solar on the grid.

“[Natrium is] an elegant solution in that we’ve taken a sodium fast reactor technology, modernized it with advanced physics, advanced materials, advanced component work that GEH did, for example with their electromagnetic pump, and we’ve supplemented that . . . and solved a new problem for the 2030s, which is the need for storage.”

“We know that the idea of a capital project over a billion dollars is really untenable for U.S. utilities, so we’ve targeted a commercial plant that can be sold for $1 billion or less in capital.”


Chris Nolan: The vice president of regulatory affairs, policy, and emergency preparedness at Duke Energy said that the company has already added solar power and has retired coal plants, but it needs to go further to meet its goal of net-zero carbon emissions by 2050.

“To achieve that we need to transition away from natural gas, and we’ve also determined that we need a fuel. The intermittency of renewables, whether it’s wind or solar, can’t be compensated fully by storage, so we’re looking at nuclear as a piece of our future.

“We need it to be load following, because that maximizes our ability to bring in solar and wind, but we also need it to be carbon free to reach our net-zero goals. Storage becomes the key to the solution. We’re looking at battery technology, but we’re also looking at the Natrium reactor because the liquid sodium provides high temperature and low pressure, which makes the reactor safer and more efficient.

“Thermal storage allows us to de-link the turbine from the reactor. The turbine can follow the load on the grid, allowing us to maximize our import of solar, while the reactor operates at steady state, maintaining its maximum efficiency.

“We are experienced in the siting process, the training of operators, the interface with the NRC, and so I think we provide value to the team.”


Dan Poneman: The CEO of Centrus talked about how TerraPower’s proposed investment in HALEU production using Centrus’s technology can solve the chicken-and-egg problem posed by advanced reactor designs that require a fuel with no existing commercial supply.

Executing TerraPower’s plans will lead to “the rising tide that will lift all boats in this industry. It’s good for TerraPower as well if others need this HALEU, because it’s highly sensitive to production rates, and the more we produce the cheaper it is for every consumer of the HALEU.

“It’s worth mentioning that there’s a very strong national security element to all of this, and for U.S. national security purposes we will ultimately need an enrichment technology that is home-grown, that is U.S. origin . . . and that need dovetails with the needs of the commercial industry.”

TerraPower’s ARDP proposal offers “an elegant solution to an industry-wide problem and a global climate problem, and if we could just get past this chicken-and-egg proposition, I think the future for advanced nuclear is truly bright and very exciting.

“We can build up modular cascades, and so we can keep pace with but not exceed the demand for the HALEU, which is very important, because capital costs are everything.”


Tara Neider: The senior vice president of program development for TerraPower focused on the design of Natrium.

“Our real focus was all about improving the economics of nuclear, because if we don’t have the economics, there’s really no point in developing the reactor.

“GEH and TerraPower have reinvented what nuclear can be. We largely started by blowing away what a reactor looks like and breaking it into its individual parts. Then we started putting it back together, and nothing was considered sacred. . . . We tried to reinvent things in different areas to focus on the economics.

“A sodium reactor is actually a really good temperature fit for the molten salts currently being used by concentrated solar power plants, maybe even more so than molten salt reactors, and that’s because of the temperature.

“We tried to make Natrium as simple as possible with inherent safety. That eliminates a tremendous amount of support equipment and nuclear piping. We have exceptional heat transfer, passive air cooling, and run at very low pressure.

“I think in the past, the nuclear industry was so focused on the licensing process that we kind of forgot about the economics; we lost sight of that. And we were able to set our own costs because we were different from everybody else. But now we’ve realized that has hurt the nuclear industry. We now need to focus on how we can make nuclear power cost-effective while still ensuring that it is safe and efficient.”

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