Well, fossil fuels are not an option anyway, but going full nuclear with closed cycle is much cheaper and environmentally safe. The only problem are proliferation concerns...
I disagree. I don't even think nuclear waste is that big of a problem. I think at this point is a efficiency and engineering issue. From 2010 to 2017 the $/Mhw projections in Solar have gone down by 81% while in Nuclear it was only 19%. Wind 63%. PV is lower than nuclear now. Estimates for 2022 are even more difference. Nuclear is just not worth it at this point.
https://en.wikipedia.org/wiki/Cost_of_electricity_by_source