Nuclear is not clean. At least by the way I define it. Or I, and those in the vicinity of Chernobyl, Fukushima, and Three Mile Island would define "clean".
Nuclear is not cheap. At least by the way I define it. Which includes end-of-service decommissioning;. Are you going to store the spent fuel on-site? That's very costly. And potentially, not safe.) and such. Add those in and nuclear doesn't seem such a good deal, in cost per kWh. And that is even before the potential cost of catastrophic failure. We've not yet seen a nuke power plant being the target of a car bomb or a (kinetic) missile attack. I suspect that happens once, somewhere in the world, and that'll change opinion worldwide about having a ticking time bomb anywhere near your back yard.
Now if you are talking about further research coming out with better, cheaper nuclear power generation technology, I support that. Like Liquid fluoride thorium reactor (LFTR), for example.
Geothermal is an energy source that is the greenest, cleanest form of renewable energy. I'ld like to see serious attention paid to that, in addition to research on safer nuclear methods.
Until then, ..., we'll be reliant on fossils (coal, natural gas, diesel), hydroelectric, wind and solar.