We have talked about nuclear reactors and how they work, nuclear fission and fusion, and maybe even some nuclear weapons, but what happens to all of that nuclear waste once it is no longer needed? Well, there really isn't a solution just yet, but it is being worked on!
Fortunately for us, the amount of nuclear waste around the world is relatively small. Currently, it can be stored in large storage pools, much like Olympic swimming pools, while a better solution is made.
Some countries rely on nuclear fuel refinement, basically recycling of nuclear waste, but this is a very costly processes. The current solution in places like Yukka Mountain or Onkalo, Finland, is to dig a big hole under a mountain and hope for the best. OK, a little more goes into it than that, but you'll have to listen to learn more.