TerraPower gets permission to build, not operate, sodium-cooled nuclear reactor
(2026/03/05)
- Reference: 1772743481
- News link: https://www.theregister.co.uk/2026/03/05/terrapower_sodium_cooled_nuclear_reactor/
- Source link:
Bill Gates-backed nuclear outfit TerraPower finally has approval to build its Natrium reactor. However, it may still face issues finding a steady fuel supply. And, oh yeah, it hasn't built any reactors like this before.
The Nuclear Regulatory Commission on Wednesday authorized staff to [1]issue the first reactor construction permit in a decade to TerraPower, allowing the Natrium developer to continue work at the Kemmerer, Wyoming facility where it [2]broke ground in 2024 despite not yet having secured the permit.
TerraPower's fast reactor design uses liquid sodium as a cooling agent and incorporates molten-salt energy storage, which is designed to be safer since it operates at low pressure and can rely on natural convection of the sodium coolant to help cool the reactor in the event of a failure.
[3]
"This is the first commercial-scale, advanced nuclear plant to receive this permit," TerraPower CEO Chris Levesque said of the NRC's approval. "We plan to start construction on the Natrium plant in the coming weeks."
[4]
[5]
Plans, of course, mean little when you've yet to build a working reactor.
After abandoning its [6]first super-ambitious design , TerraPower spent several years in the slightly less ambitious next-generation nuclear energy space, and broke ground in Kemmerer despite not having a reliable fuel supply. Natrium reactors like TerraPower's design require high-assay, low-enriched uranium (HALEU) fuel, as opposed to standard low-enriched uranium that's used in traditional nuclear reactors.
[7]
The US has long lacked a steady HALEU fuel supply, and while that's [8]starting to improve , most of the [9]small handful of HALEU-enriching firms have yet to scale beyond pilot-level fuel production. It's likely that the US won't have commercial levels of HALEU fuel available until the end of the decade.
TerraPower told The Register that it has made several HALEU deals since starting construction of its reactor facility and getting approval to build the actual reactor.
[10]Trump tax law keeps Bill Gates' nuclear datacenter dreams alive
[11]Nvidia bets on Gates-backed nuclear startup to keep its AI ambitions from melting down
[12]Small nuke reactors are really coming online by next year, US energy secretary insists
[13]Next-gen nuclear reactors safe enough to skip full environmental reviews, says Trump admin
"We feel confident that our [14]agreement with ASP Isotopes, plus the domestic enrichment capabilities that the United States Government is developing and TerraPower is prioritized for, will be able to fuel our Natrium reactor," a TerraPower spokesperson told us in an email.
Luckily for TerraPower, it looks to be the first Natrium reactor anywhere near the ready stage, and the company doesn't think it'll be spinning up the Kemmerer reactor until 2030 at the earliest, with hopes to reach commercial scale by 2031.
Now that the construction permit is authorized to be issued, TerraPower can get to work building its reactor - the first working one it'll actually be constructing, with no indication it's even built a working test reactor prior to this project.
[15]
That'll require a separate permit, naturally, and that one has yet to be granted. The only next-generation nuclear reactor designs approved by the NRC in the US are small modular reactor designs from NuScale. Neither of those has been built either, with a previous attempt to deploy one fizzling out when the project failed to secure enough customers to move forward. ®
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[1] https://www.nrc.gov/sites/default/files/cdn/doc-collection-news/2026/26-028.pdf
[2] https://www.theregister.com/2024/06/11/terrapower_nuclear_plant/
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aaoLEnq8HkUz349Gi51zHgAAARM&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
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[6] https://www.theregister.com/2013/07/25/bill_gates_nuclear_firm_plans_hot_salty_push_into_power/
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aaoLEnq8HkUz349Gi51zHgAAARM&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[8] https://www.theregister.com/2024/10/08/does_awards_nextgen_nuclear_fuel/
[9] https://www.theregister.com/2026/02/14/x_energy_smr_fuel/
[10] https://www.theregister.com/2025/07/16/trump_tax_law_bill_gates/
[11] https://www.theregister.com/2025/06/18/nvidia_ai_smr_investment/
[12] https://www.theregister.com/2025/09/16/small_modular_reactors_2026/
[13] https://www.theregister.com/2026/02/03/nextgen_nuclear_reactors_skip_nepa_reviews/
[14] https://ir.aspisotopes.com/news-events/press-releases/detail/61/asp-isotopes-inc-enters-into-definitive-agreements-with
[15] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aaoLEnq8HkUz349Gi51zHgAAARM&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[16] https://whitepapers.theregister.com/
The Nuclear Regulatory Commission on Wednesday authorized staff to [1]issue the first reactor construction permit in a decade to TerraPower, allowing the Natrium developer to continue work at the Kemmerer, Wyoming facility where it [2]broke ground in 2024 despite not yet having secured the permit.
TerraPower's fast reactor design uses liquid sodium as a cooling agent and incorporates molten-salt energy storage, which is designed to be safer since it operates at low pressure and can rely on natural convection of the sodium coolant to help cool the reactor in the event of a failure.
[3]
"This is the first commercial-scale, advanced nuclear plant to receive this permit," TerraPower CEO Chris Levesque said of the NRC's approval. "We plan to start construction on the Natrium plant in the coming weeks."
[4]
[5]
Plans, of course, mean little when you've yet to build a working reactor.
After abandoning its [6]first super-ambitious design , TerraPower spent several years in the slightly less ambitious next-generation nuclear energy space, and broke ground in Kemmerer despite not having a reliable fuel supply. Natrium reactors like TerraPower's design require high-assay, low-enriched uranium (HALEU) fuel, as opposed to standard low-enriched uranium that's used in traditional nuclear reactors.
[7]
The US has long lacked a steady HALEU fuel supply, and while that's [8]starting to improve , most of the [9]small handful of HALEU-enriching firms have yet to scale beyond pilot-level fuel production. It's likely that the US won't have commercial levels of HALEU fuel available until the end of the decade.
TerraPower told The Register that it has made several HALEU deals since starting construction of its reactor facility and getting approval to build the actual reactor.
[10]Trump tax law keeps Bill Gates' nuclear datacenter dreams alive
[11]Nvidia bets on Gates-backed nuclear startup to keep its AI ambitions from melting down
[12]Small nuke reactors are really coming online by next year, US energy secretary insists
[13]Next-gen nuclear reactors safe enough to skip full environmental reviews, says Trump admin
"We feel confident that our [14]agreement with ASP Isotopes, plus the domestic enrichment capabilities that the United States Government is developing and TerraPower is prioritized for, will be able to fuel our Natrium reactor," a TerraPower spokesperson told us in an email.
Luckily for TerraPower, it looks to be the first Natrium reactor anywhere near the ready stage, and the company doesn't think it'll be spinning up the Kemmerer reactor until 2030 at the earliest, with hopes to reach commercial scale by 2031.
Now that the construction permit is authorized to be issued, TerraPower can get to work building its reactor - the first working one it'll actually be constructing, with no indication it's even built a working test reactor prior to this project.
[15]
That'll require a separate permit, naturally, and that one has yet to be granted. The only next-generation nuclear reactor designs approved by the NRC in the US are small modular reactor designs from NuScale. Neither of those has been built either, with a previous attempt to deploy one fizzling out when the project failed to secure enough customers to move forward. ®
Get our [16]Tech Resources
[1] https://www.nrc.gov/sites/default/files/cdn/doc-collection-news/2026/26-028.pdf
[2] https://www.theregister.com/2024/06/11/terrapower_nuclear_plant/
[3] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aaoLEnq8HkUz349Gi51zHgAAARM&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
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[6] https://www.theregister.com/2013/07/25/bill_gates_nuclear_firm_plans_hot_salty_push_into_power/
[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aaoLEnq8HkUz349Gi51zHgAAARM&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[8] https://www.theregister.com/2024/10/08/does_awards_nextgen_nuclear_fuel/
[9] https://www.theregister.com/2026/02/14/x_energy_smr_fuel/
[10] https://www.theregister.com/2025/07/16/trump_tax_law_bill_gates/
[11] https://www.theregister.com/2025/06/18/nvidia_ai_smr_investment/
[12] https://www.theregister.com/2025/09/16/small_modular_reactors_2026/
[13] https://www.theregister.com/2026/02/03/nextgen_nuclear_reactors_skip_nepa_reviews/
[14] https://ir.aspisotopes.com/news-events/press-releases/detail/61/asp-isotopes-inc-enters-into-definitive-agreements-with
[15] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aaoLEnq8HkUz349Gi51zHgAAARM&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[16] https://whitepapers.theregister.com/
Afterwards?
Pen-y-gors
And the leftover uranium and radioactive salt goes in the recycling bag at the end of the week?
AVR
Their first reactor coming online in 2030 by the earliest and their fuel being available in commercial quantities by the end of the decade sounds like planning not luck. Delays could screw them over, but someone needs to be first to ensure that commercial quantities will be made at all.
Number6
I was always impressed by Dounreay using molten sodium as a coolant but at some point I looked up the melting point (98C) and got slightly less impressed. I guess it's better than water because it doesn't boil until 883C, so it doesn't need the pressure that water does.
Ian Johnston
The us invaded Iraq for oil. Perhaps they are invading Ira for enriched uranium.
Been there, done that
I'm from Washington State, and I recall four out of five incomplete nukes in the 80's.
First public bond failure in history.
Whoops.