Meanwhile, the Chinese expect to build some 200 or so pebble bed reactors. They don’t generate as much energy, but are very safe, and are built on top of their eventual waste disposal site.
Basically, the nuclear material is mixed with, then baked into ceramic balls. Each ball is put into what looks like a giant egg carton, so the balls are located at just the right interval.
They produce a given amount of heat for a given length of time, which then heats inert carbon dioxide gas to run turbines. The carbon dioxide gas in non-corrosive, and does not itself become radioactive.
When the balls are exhausted, the floor beneath them opens, and they are dropped into a deep rock shaft, their permanent resting place. Then concrete is poured on top of them, and the building above them is dismantled.
So the question becomes, why use a thorium molten salt reactor instead of a pebble bed reactor?
Because the PBR's are not nearly as safe nor economical as their propagandists claim. Long-term research studies in prototype reactors shows that the fuel "pebbles" leak far more radioactivity than claimed, and wear out faster.
There was a long thread about this a couple of years ago.
the huge hope is that portable assembly line built thorium reactors will produce electricity for 1/2-1/4 the cost of the cheapest coal.
Throwing away the bulk of the fuel energy content remaining within the fuel kernel heart of the pebble.