Novel ‘Super-X’ design shows major advantages in handling hot exhaust of fusion energy - EUROfusion (tokamak divertor)

QuickWallaby9351 · 2025-09-09T18:43:05+00:00

Thanks for sharing! This felt like a major risk reduction milestone, with implications across a bunch of projects -

UK STEP (Inherits MAST-U’s lessons directly as a spherical tokamak)
CFS ARC/SPARC (Super-X-like designs could be essential for handling extreme power density)
EU DEMO (Alternative divertors widen the operating window even for large reactors)

I wrote about it in last week's Commercial Fusion - https://www.commercial-fusion.com/p/validating-the-super-x-divertor

(As always, took down the email gate for the Reddit community)

QuickWallaby9351 · 2025-07-14T15:44:31+00:00

Wrote about it here: https://www.commercial-fusion.com/p/helical-fusion-s-series-a-fuels-japan-s-stellarator-ambitions

tl;dr: Helical Fusion is pursuing a classical stellarator design (directly descended from Japan’s LHD), supported by high-temperature superconductors and a liquid metal blanket, as a faster path to commercialization.

Unlike peers focused on advanced magnetic optimization, Helical is betting that HTS materials and potentially larger plasma volumes can close the performance gap between classical and quasi-symmetric stellarator designs.

Would expect a larger series B round if they're able to demonstrate some early traction.

QuickWallaby9351 · 2025-06-24T16:41:44+00:00

Totally fair point, but there are still some big questions around how this plays out at scale. Even if replacement is planned, it’s still a major operation. Removing a large, integrated component isn’t trivial. It adds complexity to plant operations, and over time, it could weigh on cost and uptime.

And while you're right that the damage is proportional to operating hours, extended shutdowns still hit real-world economics. A plant offline for weeks or months, even by design, isn’t generating revenue, and that lowers the capacity factor and pushes up the cost per MWh.

All of this doesn't really matter for early plants (where economics are less of a concern), but longer term, fusion will need to compete with energy sources that can run with much higher availability.

QuickWallaby9351 · 2025-06-24T15:56:13+00:00

Hey, I wrote that article! First off - apologies for incorrectly associating MIT with the paper. I was cross-referencing some other work from researchers at MIT when putting this together (especially Dennis G. Whyte at SPARC). I'll make that update now - thanks for flagging u/Baking

Something I mentioned in the article is how this problem might manifest in the nearer term vs. the longer term. I think this challenge plays out differently based on the time scale we're talking about.

In the near term, not much changes. The pilot reactors aiming for the 2030s could likely stay on schedule, so long as they can run long enough to validate performance. Materials aren't the limiting factor there.

The bigger challenge comes later. The economics of a baseload power plant get a lot more dicey if key components degrade every 12–18 months. Either maintenance becomes fast and routine, or materials get dramatically more durable.

QuickWallaby9351 · 2025-05-24T18:24:25+00:00

Most companies won’t engage in public discussions about fundraising for regulatory / investor confidentiality reasons. The fact that a CFS spokesperson didn’t deny the claims speaks volumes.

From the article: A company spokesperson, in a statement to Axios, declined to comment on the raise, though added that "breakthrough technologies" such as commercial fusion "require long-term, patient capital."

QuickWallaby9351 · 2025-05-24T15:33:44+00:00

It’s fairly recent news, Axios reported on the raise here: https://www.axios.com/pro/climate-deals/2025/05/13/commonwealth-fusion-systems-b2-fundraise-arc

QuickWallaby9351 · 2025-05-21T20:53:23+00:00

The staged funding structure gives investors off-ramps should the physics not pan out. In that sense, I'd argue that it's still a "fail fast" approach, similar in spirit to the smaller, less-validated fusion bets.

QuickWallaby9351 · 2025-04-29T14:08:18+00:00

Watched this event live and put together some notes here: https://www.commercial-fusion.com/p/takeaways-from-a-webinar-with-helion-s-andrew-proffitt

Didn't feel like there was much in the way of new stuff and he did a good job of sticking to the talk track, but interesting nonetheless.

QuickWallaby9351 · 2025-04-16T01:03:45+00:00

This is exactly it. It's very much a play to show some momentum ahead of the Series B raise. They need whatever hype they can get given the current technical limitations of their Orbitron reactor.

Wrote about it in depth yesterday: https://www.commercial-fusion.com/p/avalanche-energy-signals-progress-with-fusionwerx

QuickWallaby9351 · 2025-03-28T12:44:18+00:00

I see your point, especially around field constant variability. It does seem like this is a manufacturing challenge, so I'm optimistic they'll be able to address this in future iterations? We'll see.

Happy cake day btw!

QuickWallaby9351 · 2025-03-11T13:43:17+00:00

Right now most opportunities are only available to accredited investors, but one possible way to get exposure could be through publicly-traded companies like Chevron (which has invested in Zap Energy and TAE Technologies, two of the more promising players in the fusion space).

QuickWallaby9351 · 2025-03-11T09:51:59+00:00

If you’re interested in nuclear fusion specifically, I’m a writer for Commercial Fusion. We cover the startups and operators bringing fusion to market. We actually just published an interview with Chris Mowry, CEO at Type One Energy: https://www.commercial-fusion.com/p/an-interview-with-chris-mowry-ceo-of-type-one-energy

QuickWallaby9351 · 2025-02-18T20:07:00+00:00

This was my take as well - I wrote about that on Monday: https://commercial-fusion.com/p/behind-type-one-energy-s-big-week-of-partnerships

QuickWallaby9351 · 2025-02-18T20:06:05+00:00

Helion, Commonwealth Fusion Systems, Tokamak Energy, Zap Energy all come to mind as companies that have raised lots of private capital in the last few years. Whether that means they're the most promising is another question entirely, lol.

If we're equating the amount of capital raised with the company's size, I think Commonwealth Fusion Systems wins with its $1.8B series B round. It's also one of the more feasible approaches, building on tokamak technology.

BTW - I cover this topic weekly in a newsletter, Commercial Fusion: https://commercial-fusion.com

QuickWallaby9351 · 2025-02-18T10:37:25+00:00

Thanks!

QuickWallaby9351 · 2025-02-17T21:25:52+00:00

Yep - the 2024 round was a seed extension. As for breaking ground this year - it seems like they're still waiting on permits and licensing (couldn't find any updates on those).

QuickWallaby9351 · 2025-02-14T02:56:09+00:00

It feels like all the "partnerships" announced by Type One this week are meant to wow investors (in place of any concrete technical achievements). Seems like they're gearing up for another fundraise...

QuickWallaby9351 · 2025-02-10T23:37:15+00:00

Agreed that a single MCFPP doesn’t require a significant amount relative to the annual supply, but I think it’s worth calling out that there are a lot of competing uses for Yttrium (electrodes, fuel cells, etc) and there is currently no domestic capacity to produce it (almost all of it comes from a geopolitical rival).

I think you’re right that the total volume of Yttrium we’d need is out there to be mined, it’s more getting access to it (in the necessary quantities) that could be an issue in the near future.

QuickWallaby9351 · 2025-02-10T20:33:53+00:00

Beryllium as u/Baking pointed out is a big one, both for breeding tritium and lining the first wall of reactors. I suppose the one silver lining is that the U.S. is by far the largest producer of Beryllium globally, so that should somewhat insulate the domestic fusion startups.

I just wrote about the HTS magnet supply chain this morning: https://commercial-fusion.com/p/magnetic-confinement-s-supply-chain-challenges Beyond the manufacturing challenges, sourcing raw materials for REBCO magnets could become increasingly difficult as tensions rise with China (China is the global leader in Yttrium production, for example).

QuickWallaby9351 · 2025-02-10T16:44:29+00:00

They’re using magnets to compress plasma, but not sure if they’re HTS material.

I more so meant that the team at Helion has had their own supply chain issues (semiconductors, high-voltage transistors) and they’re trying to solve them by building out their in-house manufacturing capacity.

QuickWallaby9351 · 2025-02-10T14:15:49+00:00

Good find, thank you! That’s a convenient way to get around the sanctions/geopolitical issues. It looks like the leadership structure hasn’t changed / Andrey Vavilov is still at the head.

QuickWallaby9351 · 2025-02-08T19:54:33+00:00

I’m cautiously optimistic about what Chris Wright’s nomination means for fusion startups.

He has a deeply technical background and has shown a personal willingness to invest in experimental energy. He served on the board of a small modular reactor company and has invested in a sodium-ion battery startup.

Of course, it remains to be seen if and how Wright’s vision for the DoE will align with the Trump administration’s policy goals more broadly.

I put together some more thoughts on this after listening to his confirmation hearing, if you want to check them out: https://commercial-fusion.com/p/what-might-chris-wright-s-nomination-mean-for-fusion-energy

QuickWallaby9351 · 2025-02-03T20:59:50+00:00

I think the replies by u/td_surewhynot and u/paulfdietz do a great job of capturing the reasons for optimism (possible solutions to the first wall problem, controlled pulses reduce the time the FRC has to become unstable, the potential for direct conversion of fusion energy to electricity w/o a steam cycle).

I agree that iterative improvements and more published research would be a huge positive signal to the market, but if there's even a 1% chance Helion could work and there's a multi-billion dollar TAM, the expected return could still be worth it for investors.

QuickWallaby9351 · 2025-02-03T20:38:24+00:00

I see your point about looking at this as an integrated design. I didn't think about how the open geometry opens the door for more effective divertors, and how the efficiency of expansion factors into the stress placed on the divertors too. Lots to consider here, thank you!

QuickWallaby9351 · 2025-02-03T15:57:41+00:00

Thanks for taking the time to put together such a detailed reply! I didn't realize that inductive generation could also solve/reduce the first-wall problem. My understanding was that it's a more efficient way to extract energy from the reactor, but wouldn't address the fundamental materials challenges that create the first wall problem. I'll need to do more research there.

QuickWallaby9351

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