What makes uranium more economical, fuel production or some aspect of operation? And if it's the first one, is that just lack of scale for thorium or something else?
Thorium isn't ready to be fuel and must be enriched (granted, you need to do this for uranium too but some is naturally in a fissile state). So there's things like breeder reactors that enrich during the cycle but this is challenging and presents other issues such as turning it into weapons manufacturing (increase proliferation concerns).
There's a lot of small details that matter a lot. Fwiw, the parent has written a fair amount on this and runs a website with a lot of useful information for anyone curious. You can check their comments too as they usually participate anytime nuclear comes up
https://en.wikipedia.org/wiki/List_of_countries_by_uranium_r...
https://en.wikipedia.org/wiki/List_of_countries_by_thorium_r...
I've also never really gotten the proliferation concern. I mean, sure, you don't want to sell a breeder reactor to Iran. But why can't you sell one to PG&E? Are we that concerned that California could get the bomb?
Plus, isn't the proliferation thing supposed to be one of the advantages of thorium, since you can't feasibly make a bomb out of the uranium-233 it gets bred into?
The big issue with Thorium is it isn’t fissile at first, and requires an existing nuclear reactor and careful fuel management to actually be usable in a reactor.
> Isn't thorium also pretty abundant?
The reason I brought up uranium is that it is easier to fissile. So sure, there's more thorium but it requires more processing. Why use it when we aren't concerned about uranium access? Uranium is already "cheap". (We could get into an analogy with different types of oil if that helps. Like why the US produces so much, exports it, then buys a different type)
> I've also never really gotten the proliferation concern.
1) sure, the US doesn't care if California gets a bomb, but Russia and China sure do.
2) Breeder reactors are reactors that make higher elements.
Discussion of thorium are often extremely over simplified. Proliferation always ALWAYS must involve international relationships. When we get into that the logic changes. You need to consider a lot of higher order effects/connections since everything is always being used as leverage for other things.
Breeding is also a very complicated topic. Just like enrichment. Look at the Iran deal. They can do enrichment but only do much, right?[0]. Often fine because it's hard to scale and generally noticeable. But the same is true for breeding. Instead of turning one atom into a different isotope (e.g U238 -> U235) you change an atom to a different atom (e.g. Th233 -> Pa233 -> U233). This all happens in the reactor. It's hard to separate but hard to track. You can also keep breeding (fast reactor = more/high energy neutrons), where do you think plutonium comes from? The reason it is better for proliferation concerns is it increases the difficulty. At worst, you need to start earlier. But what I wanted to combat is the misinformation that thorium __can't __ be used for proliferation, making it safe for.., idk, Iran? It's good to add more barriers.
I'll also add waste. This is often discussed too. This is again fraught with nuance. We can dramatically reduce waste but we don't. There just isn't much of it and doing more fission is less economical. That is, unless you don't have lots of uranium laying around. That's the case with France, so they "recycle" their waste and in the process this dramatically reduces it. You can fit over 50 years of waste in a Costco and they do. You also can use similar technologies as thorium would need with uranium and still reduce waste. So that points us back to the opening: yes, thorium is abundant, but why go through all that effort when we got plenty of uranium which is cheap and efficient?
I recommend poking around AcidBurn's website. He has a lot of good information and I think he's written well in a way that's fairly approachable (it is nuclear, it's by default not approachable and easy to think you understand much more than you do. If you went through a physics degree this is often a confusing class taken at the upper level).
[0] When they broke the agreement and made more they suspiciously only made a small amount more which would take a long time to get enough for weapons. But they were also loud. Great strategy because public gets afraid, it's a threat, but they also signal that they're willing you deal but want to renegotiate (only experts would know this though). The interesting part is how their best weapon was our own fear and ignorance.
Nobody serious is actually saying that.
What people are actually saying that any nation would be completely fucking insane to attempt to start their nuclear program with this method. When there are proven method that already work, are far easier and with existing equipment.
Plus, using U233 also leads to the creation of elements that you really don't want and are unpractical for a long term nuclear defense policy. And they are equally as unpractical for hiding nuclear material.
No country so far has used this method for a reason, and no country will either. And that argument doesn't matter for most western nations anyway.
> We can dramatically reduce waste but we don't.
Lots of things aren't done until they are done. We should and with a cyclical thorium fuel cycle we could.
While nuclear waste isn't a real problem, we still have millions of people who think it is, and to have clear solution that anybody can just point out, is much better of an argument winner then 'just ignore the waste its fine'. Even if it is actually fine.
> There just isn't much of it and doing more fission is less economical.
Not sure what you mean. I don't think its actually true that fission isn't economical specially if you are thinking about it from a country perspective.
I did some calculation with pretty conservative assumptions for cost, using Germany at the start of the 'Grünewende' and the cost of all that. And I think nuclear would have been a far better deal for them, and its not even really close.
> That's the case with France, so they "recycle" their waste and in the process this dramatically reduces it.
They are using a very complex process. Part of the reason why in the 60s some of the smartest minds looked into molten salt is because that's in many ways easier to work with then complex solid fuels.
> So that points us back to the opening: yes, thorium is abundant, but why go through all that effort when we got plenty of uranium which is cheap and efficient?
In general you are right but a few points, uranium isn't actually that cheap. We restrict what our reactors can do because only low enriched is commercially available, limiting some of the cool things we could be doing. Enriched uranium was artificially cheap because of Russian policy. And now to supply enough, the West will need to increase its own enrichment again.
Second, its only not a big factor of the cost because PWR plants have pretty high operating cost. If you can get the labor cost down, the capital cost down, and the maintenance cost down, and the fuel cost down, you have something potentially interesting.
This of course matters far more when you are doing this as a country strategically. For an individual plant or company its not worth doing.
The things that actually makes thorium special, and an actual improvement over uranium is that you can do a thermal breeder.
> Nobody serious is actually saying that.
> any nation would be completely fucking insane to attempt to start their nuclear program with this method
| "If today's weapons were based on U-233, [we] would have no interest in switching to plutonium"
> then 'just ignore the waste its fine'
I said
>> You also can use similar technologies as thorium would need with uranium and still reduce waste.
> have clear solution that anybody can just point out
[0] https://news.ycombinator.com/item?id=42558370
[1] (pdf, it's on the last page) https://www.osti.gov/servlets/purl/79078
Thorium must not be enriched and it cannot be enriched like uranium, because it has only one isotope with a long life, thorium 232, which is the only natural isotope.
Natural thorium is not usable as a fission fuel, but it can be transformed into uranium 233, which is a fission fuel, by another nuclear reactor.
The extraction of uranium 233 from thorium has nothing to do with uranium isotopic enrichment. It is a process orders of magnitude simpler, because it is just a normal separation of distinct chemical elements.
This is actually the reason why thorium reactors have been avoided, because it has been considered that it is too easy to separate the uranium 233 from the fuel, which can be used for making nuclear weapons.
In this sense, I disagree that the process is orders of magnitude simpler. I'd argue that it's the opposite!
The idea that thorium-derived material can't be easily used to make nuclear explosives is an unfortunately persistent myth. You can easily make very nice weapons material from thorium. As the Livermore weapons designers once said:
"If today's weapons were based on U-233, [we] would have no interest in switching to plutonium" [1]
This is absolutely not the reason thorium reactors have been avoided at all.
The reality is that uranium enrichment infrastructure existed and fuel isn't a huge part of the cost.
Most of the funding happened in the early days and they were of course using uranium, people back then figured that uranium would run out and were interested in breedres. But pretty quickly, uranium was found to be pretty common.
Uranium is also just better unless you are doing a thorium thermal breeder. And that design only really works well with a pretty complex reactor setup that most people were simply not interested in.
> Thorium is more abundant than uranium
> Thorium must not be enriched and it cannot be enriched like uranium
> The extraction of uranium 233 from thorium ... is a process orders of magnitude simpler