btw,

" The Thorium path doesn't allow that, the waste is radioactive for hundreds, not hundreds of thousands of years,"

Not always good. The significant factor is the radiation released, not the half-life.

" and it is not 'self starting', but needs an 'igniter', either a uranium/thorium mis, or a particle accelerator, which when switched off shuts it all down, i.e., no runaway, no meltdown."

This may be true ( haven't checked) BUT the power produced will exceed the amount used to keep it going ONLY if there is fission occuring. No fission, net power loss. ANY reactor can be designed to avoid runaway- meltdown is caused by overheating, which can happen even to a thorium reactor- In both cases, the amount of fisionable material will determine if the mass will continue to produce heat, and creat a "China syndrome"