Helion begins work on Washington nuclear fusion plant
38 comments
·July 31, 2025captain_coffee
Do they even have the design of an actually working fusion reactor? This seems like a crucial detail that is suspiciously ommitted. "but said it remains on track to deliver power by 2028" - so casually written! I HIGHLY doubt this.
Animats
They've been through a few generations of test machines. They have something called "Polaris". It was supposed to be finished around the end of 2024.[1] Their own site still talks of it as being under construction.
Discussion on Reddit.[2]
They previously built something called "Trenta".[3] That generates two balls of plasma and fires them at each other. There's no fusion or fusion fuel. It's a test rig for plasma generation and manipulation. That was running two years ago.
"Polaris" is a scale-up of Trenta, with something to fuse, and with energy recovery. It's very unclear how far that project has progressed. If they were getting energy out, that would be big news. Helion is vague about how that's progressing.
[1] https://www.helionenergy.com/polaris/
[2] https://www.reddit.com/r/fusion/comments/1hlojqu/any_news_on...
WJW
> If they were getting energy out, that would be big news.
That's rather underselling it. If they have a proven, working, commercially viable design for a fusion power plant, they could probably just write a paper about how it works and collect their Nobel prize for physics next year.
HarHarVeryFunny
Commercially viable means more than getting energy out of it though - it also requires that the build, operation and maintenance costs over the lifetime of the machine don't outweigh the value of the net energy generated. Of course it needs to work on paper before you build it, but this is experimental science and until you have built it you haven't proved it.
creato
I'm ambivalent about whether their design can work but if they were confident in their design and have the necessary funding, a paper and a nobel prize are going to be very far down their priority list.
jjjggggggg
Maybe they’ll go the Theranos route. Don’t mind the hydroelectric dam behind the “fusion reactor.”
cornholio
I'm not aware of Helion publishing any peer reviewed data claiming a physics breakeven (the point where the total energy generated by the reactor exceeds the external energy fed in to maintain the reaction going); let alone an engineering breakeven (the point where the fission generates about an order of magnitude more energy, to allow for the energy conversion losses, cooling and fuel breeding etc. so as to actually output any useful amount of electricity); let alone an economic breakeven, where the reactor generates sufficient useful energy that its market price can allow the capital and operating costs of the reactor and associated infrastructure to be recovered in a certain number of decades.
If fusion had all three today, it would still e a though sell; fission has them and is still failing economically.
staplung
I don't disagree with any of what you say but if Helion's approach works (and that's a huge if) it would generate electricity directly, without need for a steam turbine or any of the associated plumbing. My understanding is that a big part of the cost for fission is the turbine etc.
captain_coffee
And how would you "generate electricity directly", specifically? Let's talk physics and engineering, not vague statements.
How would that energy generated from nuclear fusion be transformed into electricity "directly"? By which process / series of processes?
cornholio
Sure, they aim to extract energy directly from the field, but the three breakeven points are still important. A significant part of the energy will be lost as x rays and neutrons, since their D-H3 fuel cycle is not aneutronic; they will also have significant D-D reactions that are required to breed Tritium which they capture and then let ti decay to Helium-3.
Overall, when you look at the total complexity and energy balance of the full reactor + fueling cycle, maintaining vacuum, keeping superconducting magnets at cryogenic temperatures, tritium extraction etc. then generating an order of magnitude more energy than inserted still seems necessary to achieve engineering breakeven.
hinkley
And danger. Turbines are more powerful at high temps, and now you have hot liquids near your reactor. Or you use molten salt as a middleman so the potential steam explosions are a little farther from the reactor.
AIPedant
No, of course they don't. This is Sam Altman's fusion company, backed by Microsoft in 2023 with a signed power purchase agreement: either Altman has some serious dirt on Satya Nadella, or (more likely!) Satya Nadella is a gullible idiot who thought "Sam Altman is the Boy Genius Who Invented AI, so he can solve fusion too!"
(Remember this is same same Satya Nadella who offered Altman an unspecified CEO-level position after he got fired... while publicly admitting he didn't know why Altman was fired! If I was a MSFT investor I would be pretty upset about this.)
Presumably 2025 MSFT is more sober-minded about Altman. I wonder if they're gonna try to wiggle their way out of the PPA. Otherwise I am truly baffled.
paddw
Presumably, if it's just a per-agreement to purchase power, there's no downside in the likely case the project implodes.
AIPedant
The problem is that the agreement does not seem to specify that the electricity has to come from fusion![1] This is actually common in renewable PPAs - if the specific project doesn't come online then the provider has to find an alternative. But those are usually done with established providers which have > 0MW overall capacity. Helion does not. If the PPA is fixed amount vs fixed price, Microsoft might end up on the hook for inflated wholesale prices instead of cheap fusion.
FWIW I agree with the author of that Data Center Dynamics post, it's quite likely that MSFT and Helion are essentially in cahoots by stoking investors with vaporware. But it also seems like Altman might have sold Nadella 50MW of magic beans.
[1] https://www.datacenterdynamics.com/en/opinions/microsoft-and... This is second-hand, the agreement is not public.
hinkley
Ugh. Didn’t realize this was Altman. That’s disappointing.
Seemed like there was a certain amount of magic thinking about neutron damage but a bit less than fission typically does. Guess we’ll see.
SilverElfin
It is not exactly Altman’s company. It was founded in 2013 by David Kirtley, John Slough, Chris Pihl, and George Votroubek. These three won the ARPA-E competition around then. Altman funded the company more recently and is on the board. But he isn’t a founder or executive there.
HarHarVeryFunny
Altman's a major investor, but not the founder.
dehrmann
> either Altman...
Another option is this was to sweeten the pot during OpenAI negotiations.
trhway
>Presumably 2025 MSFT is more sober-minded about Altman.
If nothing else, that, after all the good they had done to him, should do it:
"OpenAi v. Microsoft: Altman ready to sue for unfair competition
...
OpenAI has put a potentially devastating weapon on the table: accusing Microsoft of anti-competitive practices and raising the attention of the Federal Trade Commission. It would be a low blow... "
https://en.ilsole24ore.com/art/openai-v-microsoft-altman-rea...
fcpguru
i think the idea is chatgpt-5 (or maybe 6) will very quickly solve the 3 main blockers:
1. Plasma Stability & Control
2. Neutron-Resistant Materials
3. Tritium Breeding
4. Heat Exhaust & Divertor Design
Because:
Trained on terabytes of tokamak operation data. Will Ssggest new coil configurations, feedback loops, and magnetic geometries in minutes instead of months. LLMs can read the entire materials science literature, cross-reference neutron scattering data, and propose new alloys or composites. ML models can simulate atom-level neutron impacts in hours, not months, narrowing the search space. Use reinforcement learning to optimize lithium arrangement, coolant flows, and neutron multipliers. LLMs can generate and evaluate hundreds of engineering CAD designs in parallel. Predict tritium production efficiency before we build the prototype. LLMs + physics-informed ML can propose thousands of divertor designs that maximize heat spread, self-cooling, or vapor shielding. Suggest novel coolant chemistries based on prior patents and obscure literature.
TLDR: Altman knows how well LLMs are getting at physics enough to be sure fusion will be solved very soon.
salynchnew
Wow. A lot to unpack here. "Propose new alloys or composites" is certainly quite a phrase, given the context.
Has an LLM ever generated any complex CAD design like this that has been built & worked?
ben_w
My experience using them to make OpenSCAD code is marginally better than you may expect from @simonw's pellican-on-a-bike challenge, but only marginally.
captain_coffee
Not sure if that reply is intentional trolling or schizophrenia to be honest.
xorcist
If only someone told me proposing new allows is the bottleneck to fusion engineering! I could have been rich!
vessenes
I was surprised to see any nuclear power funded in Washington, what with the state’s infinite hydro power and all, but on reflection, it may be a sort of more is more situation - along with existing hydro is tons of electrical and service infrastructure. Interesting to imagine Wenatchee becoming even more of a data center and power hub over the next 10 years.
ck2
There's an excellent PBS Space Time for that
https://www.pbs.org/video/the-final-barrier-to-nearly-infini...
khalic
RIP PBS
trhway
with power hungry AI datacenters popping up like mushrooms after a rain the timing couldn't be better for fusion. I guess VCs see that too. Well, some VCs also paid for that back then https://en.wikipedia.org/wiki/Rotary_Rocket - single stage half-helicopter half-rocket to orbit (and $30M in VC funding 30 years ago were really huge money) - despite 6th grade math.
gazpachotron
[dead]
https://www.helionenergy.com/articles/helion-secures-land-an...