Micro molten salt reactors make a lot of sense if looked at rationally. Can burn what we currently call "waste" too.
When talking on this kind of scale about a system level failures, the social issues are going to dominate unless it’s something like a fire-and-forget space probe. If you want to see nuclear succeed, the first thing I’d be thinking about is how to ensure that someone doesn’t cut safety to boost their profit margin, accounting for possible future regulatory capture and austerity budgets. Since nuclear is never even going to be within one order of magnitude as distributed as wind/solar, I’d especially think about what would prevent some unscrupulous CEO from pocketing the difference comfortable in the knowledge that their family doesn’t live anywhere nearby.
All of that costs money, and sooner or later some MBA / politician is going to ask why we’re spending so much on something which hasn’t come anywhere near a major event – surely we’d be just as safe spending 10% less and using the money for something else like rewarding shareholders? Setting up governance structures which can resist that kind of pressure for millennia isn’t something we have much experience with.