@blackle but yeah, as far as underwater civ using nuclear power, I don't thing it would be safer, but it would be more sustainable and viable. Like, it's possible (and economically viable) to harvest and filter uranium and other nuclear fuels directly out of ocean water using structures that resemble an artificial, plastic kelp forest.. There's an estimated sum of 4.5 billion metric tons of uranium diluted in the oceans that's easy to harvest.