Wired Magazine has an interesting article on using thorium for nuclear power. Benefits inlcude the fact that the half-life of the wastes is on the order of hundreds of years (instead of 24,100 years, as for plutonium 239), and

you could use thorium in an entirely new kind of reactor, one that would have zero risk of meltdown. The design is based on the lab’s finding that thorium dissolves in hot liquid fluoride salts. This fission soup is poured into tubes in the core of the reactor, where the nuclear chain reaction — the billiard balls colliding — happens. The system makes the reactor self-regulating: When the soup gets too hot it expands and flows out of the tubes — slowing fission and eliminating the possibility of another Chernobyl.

The article points out that, while thorium use was advocated long ago, uranium won out because

Uranium reactors had already been established, and Hyman Rickover, de facto head of the US nuclear program, wanted the plutonium from uranium-powered nuclear plants to make bombs.

Thorium was championed by one of the heads of Oak Ridge National Laborories, Alvin Weinberg.