Thorium breeds uranium 233. Even I could build a nuke out of uranium 233 if I had enough.Thorium's big advantages are that it's more abundant, has reduced radio active waste stream issues like the lack of those heavy 10,000+ year half-lived elements, as well as lower risks of weapons grade material proliferation because it's difficult to extract Plutonium from the waste stream. It also has some interesting possible applications like continuous refueling in molten salt reactors.