Noun
a submarine that is propelled by nuclear power
Source: WordNetIn 1965, USS Sculpin (SSN 590) became the first nuclear-powered submarine to be maintained at PSNS. Source: Internet
It seems to refer to some kind of nuclear-powered submarine used by Special Operations Forces. Source: Internet
S-80-class submarines. citation Nuclear power main Battery well containing 126 cells on USS, the first nuclear-powered submarine Steam power was resurrected in the 1950s with a nuclear-powered steam turbine driving a generator. Source: Internet