TL;DR: Combining a particle accelerator and a nuclear reactor to turn Uranium-238 into Plutonium-239, which then fissions. The reactor itself is subcritical, so if the proton accelerator turns off then the reaction stops.
The main advantages of the system claim to be ‘increased efficiency of fuel use’ since the uranium doesn’t need to be enriched, the ability to burn long-lived nuclear waste, as well as the system being passively safe.
The first point strikes me as an odd thing to focus on, since all nuclear reactors are already very fuel efficient, and if you want maximum efficiency then breeder reactors exist already, which produce more fissile material than they consume - you can’t get much more efficient than that. Fast breeder reactors are also great for burning up nuclear waste too, but they never really took off because, well, there isn’t actually much nuclear waste to use, precisely because typical reactors are already very efficient: A reactor might consume one ton of fuel per year. You could fit all the spent nuclear fuel humanity has ever used into a single swimming pool. I mustn’t be too critical though - any attempt to close the fuel cycle is good, I just don’t think it’s a really pressing issue. Lastly, being passively safe is cool and all, but almost all new reactor designs are, and attaching a particle accelerator to a nuclear reactor sounds like an expensive way of doing it.
All of that being said, I’m always interested to hear about new reactor designs, so I guess we’ll see how it goes.
You could fit all the spent nuclear fuel humanity has ever used into a single swimming pool.
Around the U.S., about 90,000 tons of nuclear waste is stored at over 100 sites in 39 states, in a range of different structures and containers.
I’m fairly sure a swimming pool can’t hold 90 Kilotons of nuclear waste.
Also, not needing enriched uranium is a pretty big deal, considering it’s an expensive process. And just having an enrichment facility is enough for the UN to stop and take notice, start flailing around with their arms in the air, and scream about nuclear weapons projects.
Another poster already mentioned that transuranics and other such byproducts tend to be very dense, so a swimming pool can in fact hold tens of thousands of tons of spent fuel. Also, ‘nuclear waste’ is a generic catch-all term that includes less radioactive material, compared to ‘spent fuel’ which is just the really ‘high-grade’ material.
The part about not needing enrichment is worth discussing, but we do have solutions to that already. There are entire classes of reactors dedicated to not producing weapons byproducts or needing enrichment using the same processes capable of generating weapons-grade material. The reason we see reactors that can make these materials so often is because many of the early reactor designs (many still in use today) were explicitly selected for use by the US government during the early days for their dual-use ability to make plutonium for nuclear weapons. Examples of proliferation-safe designs include molten salts and integral fast reactors, but there’s an engineering experience chicken-and-egg problem - they don’t get built very often because we don’t have experience building them. A new design like this will face the same challenges.
I just wanted to say that at a volume of an Olympic swimming pool of 2500 m³, and a density of plutonium of 19.85 g/cm³, a pool can contain about ridiculous 50,000 tons of plutonium
Theres always someone who does the math for me and I appreciate you.
I was thinking “90,000 tons is a LOT, But swiming pools are also a massive volume and nuclear material is very dense… hmmmm”
Where do you get your science…
