A reactor-powered ship cannot assume access to every friendly port on its route. New Zealand is the clearest named example of a nuclear-free policy that can exclude it entirely, while even nuclear-armed navies certify only selected facilities to receive reactor-powered vessels. Carrier size sometimes hides the problem because many ports could not accommodate a 100,000-ton ship in any case, but a smaller nuclear escort would encounter the policy directly. The United States once had to resolve this issue for the carrier forward-deployed to Japan. Port certification therefore constrains basing, diplomatic visits, and operational flexibility in ways that do not appear in a simple comparison of fuel endurance.
Chapter · 25:49-27:16
Nuclear certification limits port access
Nuclear ships cannot automatically enter every allied or domestic port, turning safety certification and public policy into operational constraints.