Nuclear power has its own mining and rare material problems, in the form of uranium. You have to dig into the earth for it, and then after you use it, poison part of the planet forever. We still dont know what to do with all the nuclear waste we alrwady made.

Thorium is 3-4 times more abundant than uranium, is generally safer to use and would produce less waste that is also less radioactive and can become safe in a reasonable timeframe (few centuries compared to few hundred/thousand? centuries). Historically the main issue with Thorium has been that it’s not as sexy as uranium because you can’t make nuclear weapons out of thorium.