Real or mischaracterized "nuclear waste"
The water-moderated reactors used today are incapable of fissioning all the long-half-life elements. PRISMs, though, can do that handily, enabling them to extract all the energy in uranium rather than the 0.6% now recovered in today's reactors (or 0.8% with the sort of reprocessing done in France, which is NOT a solution). But even with fast reactors there will be nuclear waste, because some of the elements you get from fission reactions are radioactive but not fissionable. Their half-lives, though, are far shorter. So the waste you'll get from a PRISM will only be radioactive beyond the levels of natural uranium ore for a few hundred years, and entombed in non-leaching glass or ceramic, thus solving the "million-year problem".
Several countries are working on this type of reactor and its all-important metal fuel system. The question is which country will be the first to demonstrate it. GE is making it easy for the UK to say yes with their risk-free proposal. Let's hope the country recognizes and grasps the opportunity to take the lead in this truly transformative technology.
