I appreciate that this distinction probably won't matter to you, but for others, there is a big difference between a nuclear weapon (i.e bomb) versus a nuclear powered submarine (which may or may not even carry any kind of bomb or torpedo or weapon). These submarines are using nuclear power because they are quieter and more powerful than other types of submarine engines, they are not currently planned to carry nuclear warheads which would unleash massive doses of radioactivity upon their targets. And yes, I am aware that (as Fukushima, Chenobyl, Three Mile Island and other incidents show) accidents can happen, so any of these submarines could certainly produce a nuclear disaster.