Its definitely a sidebar subject. "Yo, irradiated places probably are still radioactive. Half-lives are very long, generally."
But as a note, the example of nuking a spaceship and then coming back isn't exactly perfect. For an abandoned nuclear warhead storage facility (metal gear...?), then its a point. But the nuclear byproducts of nuclear weapons (at least now) are usually gone in a few months. Deep irradiated soil may be tainted for a lot longer (I can't remember, but its cobalt-60(?) that lasts long enough and is put into the dirt from a blast that causes this). Or, if not gone they're reduced to a reasonably safe level to be frollocking about in.
But its a thing determined by the type. The warhead magazines, probably not good place to be chilling when the containment is deactivated. A ship that was killed by a nuclear missile, it'd probably be safe to board (there's nothing there to become radioactive. The nuclear material was used up in the blast, and a good amount of residual material likely got blown clear of the place detonated. Its kinda just stuck on earth, nowhere to go).
Good point to include though.