Civilizational Drought: A Missing Category in the Understanding of Iran's Water Crisis

[NNadir]

5. There is a certain amount of hype about thorium, although it does have some advantages, in particular...

...one very relevant to Iran in this times, of making uranium enrichment unnecessary in the case where nuclear fuels are continuously recycled.

Certainly its use would reduce the radioactivity associated with lanthanide mine tailings that drive the useless wind industry and other industries involving magnets, the best magnets being neodymium-iron-boride magnets spiked with dysprosium.

It is often represented that there is more thorium on the planet than there is uranium, but this refers to terrestrial ores. Thorium is not soluble in seawater nor in river water, and thus is not subject to a geochemical cycle as uranium is. Effectively this means that uranium, which cycles from the Earth's mantle from crustal uplift and volcanoes, is extracted into river water, and ultimately into seawater (where it is in low but recoverable concentrations) is inexhaustible; thorium is not, although it is probably true that lanthanide mine tailings might supply all the world's energy demand for many centuries, if not longer.

Kirk Sorensen certainly drove interest in the MSR, a concept that stimulated a lot of my thinking about nuclear energy, but I kind of agree with Nick Touran, with whom I've recently become familiar, that it's not a magic. However the Chinese have apparently built and operated an MSR. At the end of the lecture at the link - apparently even some fusion guys have got the "thorium bug" - he makes some remarks on the Chinese MSR. For various reasons, I don't like FLIBE as a coolant, heat transfer fluid, and the materials science question, the requirement for Hastelloy, is to my mind, problematic.

We don't know many of the details of the Chinese effort, whether for instance, they've just reproduced Weinberg's reactor from the documentation, or if they've modified it considerably.

I'm not sure how much thorium is in the Baotou lanthanide tailings. It could be significant, but I believe their ores are bastnasite, not monazite. I do know these ores are weighted toward the light lanthanides, and thus one would expect thorium to be there as ThO₂ behaves rather like cerium, albeit lacking the +3 oxidation state, but I don't know.

India is definitely in the catbird seat with respect to thorium, and they are actively pursuing its use as a fuel in a way in which I strongly approve, in heavy water reactors. I understand that Australia also has considerable thorium.

I actually like thorium in solid phase fuels, chiefly as a tool to drive continuous uranium recycling without the necessity for enrichment. Uranium enrichment is always an excuse that the Repukes use to start fossil fuel wars.

I'm a uranium/plutonium kind of guy at the end of the day, but I certainly have no objection to thorium fuels, in any of the often discussed permutations. The reactor idea I'm trying to dump on my son before I die would be a breed and burn type with mixed thorium/uranium ceramics driven by critical americium from which one can apparently get a lot of neutrons.

I don't really buy into thorium as the "best thing ever," although the non-proliferation value I discussed here recently is certainly worthy of consideration. It's a part of the program, not the soul of the program. In writing that post I learned something that actually escaped my attention for decades, which is that ²³⁴U has a critical mass. I didn't know that, probably because I never bothered to check. That's a cool thing to know, since thorium will generate a lot of side product ²³⁴U because of the relatively long half-life of ²³³Pa, the precursor of ²³³U.