Nuclear fission is at a dead end. Long history of going overbudget and overschedule. SMRs are several years away from being proven, if they fullfill their promise at all; fission is littered with The Next Big Thing that ended up being a fart in the wind.

Fortunately, it's also unnecessary at this point. Getting to 95% solar/wind/storage is a very achievable goal compared to getting to 100%, and that would be huge.