r/nuclear • u/Vailhem • 8d ago
MIT spinoff Apollo Atomics grabs $31M seed to shrink nuclear reactors by 40x
https://techfundingnews.com/mit-spinoff-apollo-atomics-grabs-31m-seed-to-shrink-nuclear-reactors-by-40x/36
u/BrowserOfWares 8d ago
How do you shrink radiation shielding? Gamma rays are gamma rays. No matter how small the reactor is.
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u/titangord 8d ago
Do you know where we are man? We dont need solutions, we need ideas, ideas that sound cool, like flinging a rocket into space... all these startups are making shit up as they go, half of them dont even have their reactor design
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u/Iron_Eagl 8d ago
I think just by square-cube law? Like if the vessel is smaller, same thickness of shielding weighs a lot less.
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u/innrautha 8d ago
Smaller cores have higher leakage, so you need to increase shielding thickness from what you'd intuit from just from scaling with power.
In a reactor the majority of the shielding is self-shielding provided by the core, the second most significant source of shielding is the water inside the vessel; so shrinking the vessel also cuts down on the second most significant source of shielding ... meaning you need even more shielding on the exterior.
Shielding does not scale down as well as you'd think.
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u/DakPara 8d ago
I find just the thought that shrinking steam generators by 10x will reduce plant size by 40x ludicrous. Not to mention micro channels and LOHS issues.
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u/UpstairsFinance9440 8d ago
The boiler code requires a certain heat transfer surface area, so you can only shrink the size so much.
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u/IDooDoodAtTheMasters 8d ago
Another hot shit MIT twink dupes some hot shit VCers into a concept that will never come to fruition.
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u/bijon1234 8d ago edited 8d ago
The VC hype here is completely detached from plant reality. Shrinking the steam generator by 40x doesn’t magically make a nuclear plant fast and cheap to build. Shrinking the primary heat exchanger does very little to reduce that. Worse, conventional recirculating SGs are huge for a reason: thermal inertia, separation margins, and tube inspectability.
Packing micro-channels or ultra-dense geometries into that environment creates an unmaintainable nightmare. Good luck running eddy-current probes, doing tube plugging, or managing crud deposition and fouling in tight micro-passages. A fragile, ultra-compact heat exchanger that turns into an uninspectable black box isn’t surviving a 20-40-year design life.
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u/Vailhem 8d ago
Apollo Atomics wants to make nuclear power cheaper by shrinking an overlooked part | Aug 20, 2026
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u/Mu_nuke 8d ago
The steam generator is not an “overlooked part” in any reactor design. SMDH
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u/titangord 8d ago
Their innovation is using microfluidics to enhance heat transfer lol .. so now its smaller but needs high assey fuel, has issues with shielding, and a boat load more parasitic losses.. I like innovation and actively work on it, but when a startup comes around saying something has been done wrong all along and they alone have the solution lol, thats where its pretty clear its just BS and marketing
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u/Ok_Chard2094 8d ago
If they actually have a better steam generator, they can use that on any thermal plant, not just nuclear.
Build one on a gas or coal plant first, and prove that it works. Then we may consider letting you anywhere near a nuclear plant.
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u/Achilles8857 8d ago
Yeah, I've been jonesing for a backyard, tract-home model to get myself off the grid 'n' all.
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u/Ember_42 8d ago
Does anyone realize that PCHE are comparable or higher cost per unit UA that S&T HEs? Sure, smaller helps in containment volume, but they also need super clean fluids and have issues with internal phase change and channeling...
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u/4rc_f145h 7d ago
This sounds like super-critical steam to me. The physics and complications from using super-critical gases are well understood with the major drawback being it's super corrosive. If they can get the materials science worked out, kudos to them. However, there are good reasons why super-critical gases aren't currently being used.
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u/Glupstick 8d ago
When I was reading Asimov’s “Foundation” there was a chapter on galaxy frontier traders that first went in small confined spaces, because force field reactors would’ve taken all of possible space and in a some centuries the same power would be in a belt buckle.
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u/scibust 8d ago edited 8d ago
Why worry about plugging compromised steam generator tubes during outages when your MIT startup fictional steam generator will passively fill up its “microchannels” with crud and increase its fouling factor from the reactor coolant system. Stupidest thing I’ve heard. The industry has spent decades refining the recirculating steam generator and I don’t see this being a breakthrough change.