Out of interest - anyone know why we've not re-visited thorium?
The US military invested mightily in the current uranium/plutonium nuclear tech. Commercializing a thorium reactor would require another very large investment, one beyond a single utility company.
Even though we strongly suspect thorium would make a better power plant reactor, we won't know that until we complete a substantial part of the research and build a few generations of pilot plants. That's a risk whole governments can bear, but not a single utility.
Politically, the fusion folks have promised 'Clean limitless power real soon now (TM)' for decades, sucking up most power research funding without even producing a working pilot power plant. In 1960/1970 it was not fusion power time. We spent research money very inefficiently trying to force fusion far ahead of the tech curve. We could have had working thorium reactors for far less than we've spent on fusion, giving us much cheaper power. That cheap power would have grown our economy which would have accelerated tech advances and increased the amount of 'spare' economic power available for power research. With that, we'd have a better tech foundation for fusion and would be able to fund it at a higher level.
I think we should fund preliminary thorium power research right now, with plans to shift the majority of fusion funding to thorium if the current large fusion test doesn't work out or goes into 'real soon now stalling' - er I mean delays.