No, GP is averaging out across the whole day. If you get 100W during daylight and 0W during night, you can average to 50W for an entire 24-hour period. GP took 30W as a conservative estimate, which is entirely reasonable.
And on top of that were are you getting the additional batteries to provide extra capacities for when the sun is shining at less than 100% of optimal?
And then where are you getting all the materials for those batteries? And what are you doing with all the waste from those batteries once they end their serviceable lifespan?
If you seriously are concerned about the latent costs with nuclear power plants then you should do more than gloss over the storage issues with solar.
And many of your concerns about nuclear fall apart if you don't assume we would continue to build reactors with the issues you point out. There are new designs like micro molten salt reactors that address in pretty signifiant ways the concerns you note. A lot fewer construction materials, greatly simplified designs and designs that don't rely on active cooling to prevent a meltdown. Designs that if the reactor systems are interrupted, the reactors coast to a shutdown naturally.
It's not science fiction - its proven technology we've had since the 50's that was refined in the 70's but squashed because of politics and fear mongering.
Maybe after China starts eating our lunch we'll take it seriously? Ha - probably not even then, unfortunately.