The waste is purely a political issue. In the left corner we have a coal plant. In the right corner we have a nuclear plant with the same output, as well as a

The waste is purely a political issue. In the left corner we have a coal plant. In the right corner we have a nuclear plant with the same output, as well as a reprocessing setup. They run for a year, both have produced waste. We dig identical landfills for both of them and bury the waste. Next year we need to dig a new landfill for the coal plant, but the nuke one has plenty of space left. 10,000 years from now the nuke landfill finally fills up--but the first waste we have put in it has decayed to ambient and no longer needs any special storage. Accidents: The worst nuke has ever done is no worse than normal operation + unfortunate weather has done with coal many times. With even halfway decent safety measures we should be looking at Fukushima as the worst likely event--and note that the death toll ascribed to Fukushima is purely political, had they not evacuated the city the expected death toll was zero. I wouldn't advise farming around there for a while but otherwise it should have been life as normal. Weapons: At the nation-state level you can't prevent this. At the terrorist level there's a pretty simple defense--your reprocessing plants put some of the waste back into the fuel. Most of the waste that builds up is irrelevant to the reactor, it's a few neutron absorbers that cause the problems. Take those out, put the gamma emitters back in. Even new fuel rods are therefore wickedly hot. Since both the reactors and the reprocessors already have the robotic equipment to handle the wickedly hot spent rods this causes only very minimal issues, but it makes stealing material very dangerous and very easy to spot--you can't hide a gamma emitter with any shield you can smuggle out. I will object about the small reactors, though--we do *not* want shipboard reactors for civilian use! To keep them small enough those shipboard reactors are fueled with weapons grade uranium.