> Australia is the best case scenario for solar power.
Yes. (and no - it's a big country)
The USofA is also a large country with the same land area (mainland USofA at least) and many places suitable for solar and wind.
The South Australian capital, Adelaide, is on the 35th parallel (South), what works there likely works in the US at or below the 35th parallel North.
The essential point is that nuclear isn't a flat parameter free answer to all that ails - some places it makes no economic sense, other places it makes good economic sense ... and there's a world in between.