I'd think more nuclear would be better for environment. Since sun does not shine around the clock and other renewables have larger negative environmental impact. Batteries for storage is not good either with today's technology.

Pure nuclear, or even as a majority production method, would be fool's errand, though. Unless someone manages to invent small enough reactors that can be started and stopped at will, to adjust a day's power demands. I doubt that can even be possible, though.