A nuclear submarine is a submarine powered by a nuclear reactor. The performance advantages of nuclear submarines over conventional (typically diesel-electric) submarines are considerable. Nuclear propulsion, being completely independent of air, frees the submarine from the need to surface frequently, as is necessary for conventional submarines. The large amount of power generated by a nuclear reactor allows nuclear submarines to operate at high speed for long periods of time; and the long interval between refuelings grants a range virtually unlimited, making the only limits on voyage times being imposed by such factors as the need to restock food or other consumables.

Current generations of nuclear submarines never need to be refueled throughout their 25-year lifespans.[1] Conversely, the limited power stored in electric batteries means that even the most advanced conventional submarine can only remain submerged for a few days at slow speed, and only a few hours at top speed, though recent advances in air-independent propulsion have somewhat ameliorated this disadvantage. The high cost of nuclear technology means that relatively few of the world's military powers have fielded nuclear submarines. Some of the most serious nuclear and radiation accidents ever to occur have involved Soviet nuclear submarine mishaps.

Type: Nuclear-Powered Attack SubmarineDisplacement:
3,075 long tons (3,124 t) surfaced3,513 long tons (3,569 t) submergedLength: 251 ft 8 in (76.71 m)Beam: 31 ft 7 in (9.63 m)Draft: 29 ft 5 in (8.97 m)Propulsion: 1 × S5W reactor2 × Westinghouse steam turbines, 15,000 shp (11 MW)1 shaftSpeed:

20 knots (23 mph; 37 km/h) (official)~31 kn (36 mph; 57 km/h)