No, I said it wasn't a nuke sub. Nukes, nuclear weapons. To nuke, to use nuclear weapons. The correct description is that it is a nuclear-powered submarine. Nothing else will be anywhere near as clear. It would be perfectly possible for a nation that wasn't a nuclear power to have nuclear-powered subs, but they wouldn't have nuke subs. If you call it a nuke sub there is every chance that some people will think you're talking about a submarine carrying nuclear weapons. It isn't hard, this stuff.