"considering the "waste" of power plants is what you put in bombs."
Not in general - spent nuclear fuel from a reactor that's been running for 18 months has a lot of fision products and decay products which make worthless for use in weapons. If you really want to create weapons grade plutonium, you put fuel slugs in the reactor and only run the reactor for something like 30 days, then pull the fuel out - you breed enough plutonium to extract, while not producing much of the "junk" which ruins it for weapons use. But, you can't breed much in 30 days. So, you need to do this over and over and over, then take all that fuel, run it through a PUREX type reprocessing plant to seperate the Plutonium, and enrich the PU up to 90%+ purity.
Because of this, no nation has EVER made bombs from spent nuclear fuel - they use dedicated-purpose reactors for making bomb material. Now, on the other hand, *enrichment* facilities are of great concern, because if you can enrich uranium to 5%, you can enrich it to 99%, and make a Uranium bomb. But, for a uranium bomb, you don't need a reactor at all.