Some key insights from the article:
Basically, what they did was to look at how much batteries would be needed in a given area to provide constant power supply at least 97% of the time, and the calculate the costs of that solar+battery setup compared to coal and nuclear.
According to the link you listed an AP1000 costs $66/MWh where as from the ember report that’s linked in this article solar plus storage for 97% uptime cost $104/MWh in a sunny city. In Washington DC it would cost $124 and only be able to maintain 81%. I still stand by even with the higher cost that solar + storage is a better option in places like Arizona, Nevada, Southern California ,etc. but nuclear is not as much of the high cost boogeyman as you are making it out to be
https://ember-energy.org/latest-insights/solar-electricity-every-hour-of-every-day-is-here-and-it-changes-everything/