Grid-scale sodium batteries are already in production, and there isn’t some kind of magic anti-technology shield which keeps the United States in the 1920s.

When talking about cost, it’s important to remember that solar+batteries are already cheaper and, unlike nuclear, happen on much shorter timescales. I’m not opposed to some nuclear plant starts but those guarantee a couple decades of increased pollution before there’s any chance whatsoever for carbon reduction, whereas solar can come online in a year.