1) Why was the Oak Ridge experiment (MSRE) terminated ?
The fatal report is WASH-1222 and was written by Milton Shaw of DoE. Shaw was a super-bureaucrat actually sent by Admiral Hickover, in charge of light water reactors in the US Navy. The simple reasons are that MSR can't breed plutonium for weapons and that the MSR program was competing with Hickover's name recognition. Financing a dual technology in the midst of the Cold War was deemed to costly. At the time, uranium was perceived to be in shortage so maximising the use by efficient breeding was the single most important consideration.
2) What about waste coming out of a MSR ?
SInce a MSR churns on the fissile inventory continously for 30-60 years, the most radiotoxic and longlived isotopes like Neptunium, Americium and Cerium, called TRansUranians (TRUs), are reduced to negligible levels. For comparison, a fuel rod can only stay in a light water reactor for 1 year. During this year the problematic isotopes only have time to appear but not to go away.
Therefore the waste coming out of a MSR is not TRUs but Fission Products (FPs).
3) How dangerous are FPs ?
FPs should be stored out of reach for human exposure for some hundreds of years, say 1000 years.
However handling these FPs are much easier than TRUs that need 100 000 years in isolation.
4) How safe is the MSR ?
The MSR can not simply boil over neither melt down. Socalled thermohydraulic properties of the salt melt act like an ABS in cars. Push the brake pedal as hard as you can and you still get a nice smooth optimised break in. Add more fissile material than nominal, the melt will expand and quench extra reactivity.
5) Is thorium expensive ?
In the context of energy production : absolutely no ! Thorium comes out as a byproduct to Rare Earth Elements (REEs), a group of products little known but crucial to all advanced mass consumer products. Thorium can cost 10 000 € per kg without showing up the in the kWh cost.
6) Why do you sometimes spell "torium" ?
Well, the element was discovered by a Swede. He named it after the viking god Tor, the fierce guy who hammers out thunder and lightning when sledging across the sky. Actually much of the world's torium is located in Norway. We want a Nordic collaboration or a Nordic touch. And the websites with "thorium" are all taken.