It is incredible for nuclear-sceptical analysts who grew up in the 1970s to see thorium and fast breeder reactors positioned today as 'new' and 'promising' technologies given that the technologies formed a lot of the truly horrific nuclear futures opposed by the anti-nuclear movement at the time. It is remarkable to see some high profile greens actually suggesting we ought to support research into these options.
Partly people do it because of the sheer cost and unappealing nature of schemes like Hinkley C. They seem to think that thorium and fast breeder reactors are supposed to be a 'modern' and 'better' alternative, and appearing to not reject all nuclear options seems to be a good way to appeal to the dominant (outdated) pro-nuclear fantasies of the British scientific and engineering establishment.
Oh Dear! Us oldies have got a lot to learn from the young'uns and their new IT, battery and solar electric car visions and efforts, but sometimes it is the other way around. People who seriously think that thorium and fast breeder reactors are somehow an alternative to the fading 'conventional' nuclear power technologies of today ought to revisit some of the histories written in the 1970s and 1980s.
Fortunately we still have some analysts who are prepared to revisit some of the arguments, history and inconvenient facts about these failed, awful, technologies. See the Bulletin of Atomic Scientists analysis, for example on http://thebulletin.org/thorium-wonder-fuel-wasnt7156