I don't think it is solved because any solution needs to be very long term, and having politicians or even much of the population care about the long term is no

I don't think it is solved because any solution needs to be very long term, and having politicians or even much of the population care about the long term is not a solved problem. Nuclear power gives us far too much ability to borrow from tomorrow to pay for today, same as with coal. That's why it is, in practice even if not in theory, not an adequate solution to our energy demands.