When considering paths forward for climate change, there always seems to be the caveat "great idea, if we went whole-hog on that 20 years ago." This is doubly true, though, for nuclear plants -- just physically building the things takes a while, even if you ignore the problems around getting a massive pile of startup cash for an investment whose payoff hinges on energy prices 20 years out.
These aren't insurmountable problems, but they are pretty big. With solar, a person can stick it on their house. A grid-level installation can be built over time and starts paying for itself as soon as the things are plugged in.
Our current plans are targeting 2030 for massive carbon reductions, right? I don't see how starting a bunch of nuclear plants now really helps there. The most enthusiastic proponents of preventing global warming have always wanted to target 10-15 years out, so the energy isn't there for nuclear. Unfortunately. It would have been nice if we'd built a bunch of nuclear reactors 30 years ago.