Comment by elric
3 months ago
Seems like China also has rather large uranium reserves, unlike many other countries, so it makes a lot of sense for them to go nuclear.
3 months ago
Seems like China also has rather large uranium reserves, unlike many other countries, so it makes a lot of sense for them to go nuclear.
Uranium 235 as a fissile fuel is a very small percentage of the total uranium available (0.720% from the wiki).
https://en.wikipedia.org/wiki/Uranium
In order to make reactor fuel, this percentage must be increased, via conversion of the metal to uranium hexafloride gas, which is purified via gas centrifuges.
As opposed to this, thorium does not require difficult purification steps, but it does require a neutron source to start a reaction that converts a small portion of it to uranium 233.
From the uranium 235 purification perspective, uranium is an awkward fuel for commercial use.
I think it's a shame that we don't breed more fuel. The majority of mined Uranium 238 can be made fissile in a breeder reactor (fast neutrons), just like with Thorium. It does require reprocessing, which is a taboo topic due to proliferation concerns.
Plutonium doesn't build up in a breeder reactor, the fast neutrons split it. Our existing light water reactors have a build up of plutonium over time. I guess that's desirable when your objective is bombs.
A lot of the long lived radioisotopes get broken down in a breeder reactor, so the waste degrades to safe levels much quicker (a few hundred years).
The Gates backed reactor (Terrapower) in Wyoming is using fast neutrons.
There is a vast supply of thorium 232, produced as waste in rare earth mining. Why breed uranium?
"Natural thorium is usually almost pure 232-Th, which is the longest-lived and most stable isotope of thorium, having a half-life comparable to the age of the universe. Its radioactive decay is the largest single contributor to the Earth's internal heat; the other major contributors are the shorter-lived primordial radionuclides, which are 238U, 40K, and 235U in descending order of their contribution.
"[Thorium] is the 37th most abundant element in the Earth’s crust with an abundance of 12 parts per million.
"The low demand makes working mines for extraction of thorium alone not profitable, and it is almost always extracted with the rare earths, which themselves may be by-products of production of other minerals."
https://en.wikipedia.org/wiki/Thorium
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> In order to make reactor fuel, this percentage must be increased, via conversion of the metal to uranium hexafloride gas, which is purified via gas centrifuges.
Unless you're using CANDU reactors which can use unenriched uranium (the trade-off is you need heavy water (deuterium, D2O) as a moderator, and producing it is an up-front cost).
Tbf importing uranium is fairly easy and relatively cheap due to the high energy density.
Importing it from where? Russia? Ukraine? China? Australia & Canada are probably viable options for Western nations, but that introduces more dependencies.
> that introduces more dependencies
Uranium does have the benefit of being very energy dense, so stockpiling it is relatively simple. Also see the IAEA Low Enriched Uranium Bank.
https://www.iaea.org/topics/iaea-low-enriched-uranium-bank
Yeah, and it's also a great way to reduce your energy dependency on certain non-friendly countries... oh wait: https://apnews.com/article/germany-france-russia-nuclear-pow...
That company is just using russian engineers for russian-designed Reactors.
Not to mention that you don't even need to do that. Westinghouse already builds VVER fuel assemblies without Russians (they are supplying Ukraine's nuclear power plants, for example)
As noted in peer comment uranium is energy dense and relatively little is required.
Also, by global known deposit standards the ore density and ease of mining in parts of Canada, Africa, Australia, Kazakhstan (!!! 43 percent of global uranium production in 2022) dwarf those in most other parts of the world.
For interest, re: Uranium in China, the initial quote here comes from
https://world-nuclear.org/information-library/country-profil...
It’s worth noting that Uranium mining uses the same nasty liquid-liquid extraction process used for rare earth metals. That’s why the mountainous locations in China suck - they have to move a lot of rock. A few countries dominate the industry because the vast majority of the world wants nothing to do with the environmental consequences of the toxic corrosive waste.
If push came to shove, many more countries would be able to spin up Uranium mining to replace any sources that fall victim to geopolitics. Since it doesn’t go bad, a relatively small stockpile goes a long way while the industry adjusts.
Uranium is mined by in-situ leaching. You don't have to move any rock (well a little, but astronomically less than for traditional mining). It's not at all similar to rare-earth mining.
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