What happens to reactors after 50 or 100 years of global/national decline due to environmental and geopolitical circumstances?
They produce no greenhouse gases.
Well actually I believe they have a rather large upfront carbon footprint, but the question is not whether they are worse than fossil fuels, but whether we should rely on other forms of "green" energy which do not have catastrophic failure conditions or rely on a competent society to safely maintain. We have already failed to stop global warming and we should expect to be in decline, so that's the future we should prepare for.