I'm not 100% in agreement with Copenhagen Atomics, although I agree a molten salt reactor is a much better design, I don't believe a thermal spectrum reactor is the best, the nuclear cross-section of thorium and many other even (fertile) transuranics is larger often for fast neutrons than thermal. And there is the issue of the moderator. Thermal reactors require a moderator and deuterium is better than protinium (regular hydrogen) in as much as it is more resistant to absorbing neutrons but water, whether light water or heavy water is chemically unstable in the face of heavy neutron bombardment and breaks down into hydrogen or deuterium and oxygen. Then if these build up faster than re-combiners can re-combine them, you can get a hydrogen explosion, this is what blew up the reactors in Fukushima.

So I am more in favor of the two salt fast breeder reactors as advocated by Kirk Sorenson. By not involving water the risk of a hydrogen explosion is eliminated and the reactor doesn't have to operate under pressure. Both of these factors make the reactor much safer AND more efficient. Plus a fast neutron spectrum can transmute virtually all of the fertile transuranics into fissile and then burn them leaving only fission products as waste. Unlike the transuranics, the fission products have a short half life and will be back to or below the radioactivity level of the original ore by 300 years, turning a million year waste disposal issue into a 300 year issue and one of much lower volume.