There are some examples I can think of where nuclear waste is being stored underground: By people: underground nuclear bomb tests Naturally: there are some spo

There are some examples I can think of where nuclear waste is being stored underground: By people: underground nuclear bomb tests Naturally: there are some spots where nuclear fission reactions have happened on their own, leaving the waste where the fissile uranium used to be These aren't going to be the same contents as what power plant waste looks like, of course, but they certainly provide some evidence on how safe/not safe it is