http://www.ted.com/talks/kirk_sorensen_thorium_an_alternative_nuclear_fu...
By inherent design a LFTR can not suffer a 'meltdown' because the fuel is already melted in order to operate. In solid form it ceases to react. And because it operates at normal (atmospheric) pressure nothing will explode.Thus using just gravity liquid fuel can be drained away into a passively cooled storage tank/area in the event of total power loss. In other words, it is inherently safer than any of the current generation of nuclear reactors, all of which require large bodies of water for cooling, and suffer disastrous consequences if for any reason water cannot be fed to the core.
In addition to that, because far more of the fuel is used (up to near-100% with enough fuel recycling), you end up creating far