A pretty interesting talk. I'm still not clear on exactly how you separate the protactinium from the thorium, but as far as efficiency and non-weaponization goes, this sure sound like it beats the crap out of U/Pu.
I still think solar and wind are better ideas in the long run. Every nuclear fuel is inherently a fossil fuel, in that there's only a certain amount in the earth's crust and it will run out at some point. Actually, even the sun will go out one day, but I'll be long dead before then, so I guess it's really a matter of exactly how long before we run out of fuel. Anything less than a 1000 years is probably a non-starter IMO.