It seems to me you are conflating in the same article several different technologies in different stages of development. Thorium is already used in what I believe are different fission cycles in India and the US.

The particular design you mention, the Rubia Reactor or Spallator, has a lot of objections to it but all theoretical. Personally the greatest question mark I see is what may happen to the molten lead coolant if you are forced to a shutdown; this probably destroys the reactor. In any event something I say would be worth researching, but the money was never there.

What I see as one of the most elegant designs is the Liquid Fluoride Thorium Reactor (LFTR) which is also sub-critical and theoretically can consume all sorts of waste generated by existing pressure reactors. This design came about in the US in 1960s and the decision not to pursue it was purely political. Luckily in recent years the Chinese have become very interested and seem ready to build a fleet on this design.

If you have 2 hours for some optimism:

luis_de_sousa@mastodon.social