Using nuclear for base load is silly. Why would you use the 12c/kWh nuclear energy while the sun is shining when you could be using the 0.5c/kWh solar instead?
Because you already built the nuclear plant to provide power at night and during periods of low renewable output, and once you're already paying to build and operate it, the incremental cost of also using it during the day is effectively zero and zero is less than any non-zero cost for needing more solar farms.
Also, the real numbers aren't actually that far apart because you're using the high end of the estimate range for nuclear and the low end of the range for solar.
To replace nuclear with solar for baseload you need the solar farms and batteries for at night and peaker plants for extended periods of low generation during the day and to maintain fueling infrastructure for those peaker plants. You add all of those up and it costs more than using nuclear for baseload.
During the day, a nuclear plant has to sell power for 0.5 cents / kWh or so. That means that during the night the plant has to sell power for double the price to stay profitable.
