US physicists in the late 1940s explored thorium fuel for power. It has a higher neutron yield than uranium, a better fission rating, longer fuel cycles, and does not require the extra cost of isotope separation.
The plans were shelved because thorium does not produce plutonium for bombs. As a happy bonus, it can burn up plutonium and toxic waste from old reactors, reducing radio-toxicity and acting as an eco-cleaner.
This is all very good news. Not only is safe for the use of it, but also waste storage. Currently, storage is a huge problem. No one wants it in their locality. Also, there is the problem of warning signs. How many people, in 1000+ years, could understand the warning signs at nuclear dumps?