An LFTR, or Liquid Fluoride Thorium Reactor, is an attractive replacement to our current nuclear technology. They advantages offered over conventional uranium reactors are many fold, and the basic concept was proven over 40 years ago.
The primary deficits of a uranium reactor are:
1. Perceived Danger
2. Fuel availability
3. Long lived waste
4. Weaponizable waste
An LFTR has none of those issues. They have passive safety systems, requiring no power to contain their nuclear materials, and are immune to catastrophic meltdown. Thorium, the main fuel, is 4 times more abundant in the Earths crust than uranium, and is not weaponizable. Finally, a LFTR produces no new waste, and can even use our current waste stockpiles as fuel.
http://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor