I still have the not-so-popular opinion that nuclear is still best on the mass scale. Modern nuke tech is so much safer. The problem is retiring and replacing these old generation 1 and 2 reactors. Those are what caused Chernobyl, Three Mile Island, and Fukushima. France is full on with modern nuclear power and have you heard of any problems there?
Not that that is at all on topic, but the real big problem in my eyes is that we have absolutely no clue what to do with the highly dangerous, highly poisonous nuclear waste - all we have so far are no more but provisional and transitional methods, with nuclear waste often shipped time and time again between some place and another. We really need to find a way to finally and properly get rid of all nuclear waste - before that's not done, I'm not really the biggest fan of producing even more of what we can't handle in the first place.