I served 20 years in the Navy. Submarines. Nuclear powered. Our only limit on how long we could stay out, or submerged, was the amount of food we could carry. Everything else we needed to survive, we produced. We took seawater, made it into fresh water, and had water to drink, cook, and bathe. We took that same fresh water...ran it through a few more processes, and had oxygen to breathe, and pure water for the battery and the reactor. We had equipment to scrub the CO2 we produced as humans, and nitrogen burners to get rid of the bad gas.
And in 20 years, not one Three Mile Island, Chernobyl, or Fukushima. Mind you, this was but one career on 5 subs while there were at least 40 others just like mine at sea. The Navy has made it's mistakes, but when it comes to running a floating nuclear power plant in conditions that would make GE engineers puke, well...there's a reason why GE, and others, hire Navy nuke engineers just as fast as they get out or retire. Hyman Rickover built a bulletproof system, and it's working to this day.
If you want to get away from fossil fuels, there is only one answer that will meet existing and projected future needs. Solar, hydroelectric, wind power, and anything "green" is a guaranteed nationwide blackout at some point.
So it's coal and gas, or nuclear. Pick your poison.