On rare occasions, I have heard of American nuclear subs make foreign ports of call. Almost a year ago, one surfaced off Norway, but did not make a port of call. These are extremely unusual, so there is something wrong with the claim that a nuclear submarine needed fuel from Norway.
I might be wrong. It just seems wrong to me for the reasons I have stated, and will state.
Running a diesel generator underwater would kill everyone on the sub. These subs spend months underwater. Coming to the surface to run a diesel generator would give away their position. Besides, diesel generators are comparatively loud, and just that gives away their position.
I seriously could not do it. Spending months in a metal can under the water, no access to the outside world. I may have my disagreement with Damocles on other issues, but I respect him for being able to serve on a submarine. That is a brutal thing, at least for me.
Once again, these nuclear submarines must stay underwater for months. They cannot just go into a foreign port once a month for diesel fuel.