The reason costs are high is not political, it's that the systems involved need to be over-engineered relative to say, a coal-fired power plant, where a breakdown or fire will create a big mess, but not a 100-year exclusion zone. Water pumps for nuclear reactor cooling systems, for example, are the most robustly engineered (and expensive) pumps ever built, as far as I know.
For example, California's decision to close the San Onofre reactor was mostly related to maintenance costs, as their steam generator system was shaking itself to pieces and had to be shut down due to the radioactive loop leaking into the non-radioactive steam generation system. The rational conclusion is that long-term maintenance of nuclear reactors is an expensive proposition, due to catastrophic failure modes:
https://www.fairewinds.org/nuclear-energy-education/san-onof...