I think the science is pretty well understood. We know how to separate isotopes and react them to create new products, but there will always be some amount of j

I think the science is pretty well understood. We know how to separate isotopes and react them to create new products, but there will always be some amount of junk that's too reactive to toss in a landfill but not reactive enough to use. Also some of it can be used to make bombs, and that makes us rightfully pretty skittish.