The thing I've always liked about nuclear was its reliability of not fluctuating based on the weather outside. Wind/Sun power is fine, but we need storage of that power for use later when wind/sun is not available. I always liked the idea of water resovoir batteries using wind/solar to pump the water so that it could be used for hydro generating. However, California seems to be a bad location for hydro like that as there's no water.
The output of nuclear plants is also affected by the weather, few years ago the Finnish nuclear plants had to reduce output in the summer due to the Baltic Sea warming up too much. Heating it even more from cooling water would damage the ecosystem.
