Doesn't seem to exist many civil nuclear powered ships at all. And barely any non-US/Russian ships, at least still in service. From my quick searches at least.
Large nuclear military ships likely have some port restrictions anyway.
The restrictions are more to do with the size of the ship, not it's propulsion mechanism.
Routinely, US Submarines and Aircraft Carriers (all powered by nuclear reactors) sail into normal civilian ports around the world for various reasons.
[1] https://news.usni.org/2016/09/27/n-z-chief-navy-u-s-nuclear-...
Doesn't seem to exist many civil nuclear powered ships at all. And barely any non-US/Russian ships, at least still in service. From my quick searches at least.
Large nuclear military ships likely have some port restrictions anyway.