World’s First Thorium Reactor Designed (opens in new tab)

You're confusing issues from pressurized reactors with LFTRs. The reason manufacturing ceramics for pressurized reactors is hard is the pressure and size involved. LFTR can be run at normal pressure at small scale; you can use a kiln as the pressure vessel if you want to.

Also, no, not any metal gets brittle; inconel and hastelloy handle radiation quite well for decades at a time, as does good old fashioned nickel. Beyond that, most reactor pressure vessels are a layer of metal then a layer of something that's really good at radiation, then the real pressure vessel, so that the interior layer's brittleness isn't very important.

We built and ran LFTRs commercially in the 1950s in New York State and Pennsylvania, before computers became a commercially realistic thing. They provided our grandparents no significant technical challenge.

The actual big problem with LFTR is primarily regulatory. The design hasn't been vetted to modern safety standards, which costs hundreds of millions of dollars, and the entities who are nuclear-aware and have that kind of money to throw around tend to be the existing nuclear companies, who can't switch to any other technology because they're deep in the Gilette Razor model, and anything that took out their existing fuel contracts would immediately bankrupt them.

There is /zero/ materials science needed to make a LFTR. I don't know where you got that idea. They're substantially easier than what we make today. The average auto body shop can pull it off.

The interweaving of complex shifting regulations with the economics of $B plants that take decades to build and involve tremendous amounts of radiation and energy is not some random coincidence, nor is the absence of Buffets and Icahns lining up to make a killing on the erstwhile Future of Clean Energy (as opposed to wind and solar). If thorium can't solve the political economy problems, then thorium is dead. A small loud group of techies yelling "don't you get it?!" and upvoting thorium posts on HN is just part of the ??? between underpants and the profit we will never see.

Fast reactors and liquid thorium reactors would produce about one percent as much waste for the same amount of energy.

I just went past one on the train to work. They're everywhere!

If everyone in the world had enough energy to live a developed-world middle-class lifestyle -- and with thorium reactors this might be feasible -- might that not eliminate one of the driving forces behind global conflict?

I'm not saying it's a slam-dunk win for sure.

But I have noticed a lot of general apathy and aversion to violence in the developed world largely because people are just too busy living their lives; they have a lot to lose.

> the real question is how they plan to reduce the U-232 contamination level enough to make weapons-safe U-233

I'm not convinced that anyone has this goal in mind. Maybe they just want to provide power to their countrymen and continue to lift India out of poverty. There might be nothing nefarious about this, unless you consider poor people getting less poor to be a problem.

I don't understand the whole "it has to be capable of making bombs to be viable" thing.

I mean, the local coal power plant can't make artillery shells, but we're not shutting it down...

Thorium is not a fissile isotope - meaning it can't be used for fission directly. It needs to be transmuted by neutrons into uranium 233 (which is fissile). By this measure, thorium isn't any better than Uranium 238 - which is 99.3% of naturally occurring uranium. So "All but a trace of the world's thorium exists as the useful isotope" - can be applied to uranium also. Uranium 238 is also a fertile isotope - and doing a completely fair comparison, uranium doesn't need to be enriched either... Except the only way we have to convert fertile isotopes to fissile isotopes is to expose them to a sustained, high neutron flux which is typically only economically achievable using enriched uranium (via the naturally occuring U235 isotope). Thorium breeder reactors need enriched uranium as much as uranium breeder reactors. So while thorium has some advantages, I wouldn't say that natural abundance or supply are particularly significant.

[Edit] corrected use of "fissile" -> "fertile"

> rough estimate shows that if all our current electric energy demand would be satisfied with Uranium, the reserves would run out in roughly 10 years.

While strictly correct, this is extremely misleading. Current resources would be exhausted in a decade, but resources are defined as the known deposits extractable under current market prices. Should we actually start using a lot of uranium, the price would spike, which would lead to a lot more deposits becoming economically available. This has almost no effect on the cost of nuclear power, as the cost of the raw uranium isn't a large part of the cost of producing power.

The end game there is when the price rises sufficiently for extraction from seawater becoming profitable. The world's seas have ~1000 times more uranium than conventional ground-based resources.

Nuclear fuels will not run out in this millennium.

That estimate for uranium assumes conventional reactors, which fission U-235. That's 0.7% of natural uranium.

For a real comparison, you should look at fast reactors, which use the rest of the uranium. That takes your estimate up to about a thousand years. But the estimate is looking at economically recoverable reserves, and if the same ore produces a hundred times as much energy, a lot more becomes economically recoverable.

Thorium would be 3-4 times more abundant than that. (But if seawater extraction works out, uranium will have the advantage again.)

This estimate doesn't seem to account for enrichment. For every KG of uranium mined, you get a much lower ratio of enriched fuel.

If it's 3-4 times bigger than the Uranium, and Uranium will last us 10 more years - Thorium would last us 30-40 years. What to do after that?

If there ever appears a new intelligent civilization millions of years after humanity, they'll be very disappointed to be on an Earth without any Uranium or Thorium!