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Nuclear submarine

U.S.S. Michigan (SSGN-727): An Ohio Class guided missile submarine

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 durations; and the long interval between refuellings grants a range limited only by consumables such as food. 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; recent advances in air-independent propulsion have eroded this disadvantage somewhat. The high cost of nuclear technology means that relatively few states have fielded nuclear submarines.



The US launched the USS Nautilus, the first nuclear submarine, in 1954[2]. Nautilus could circle the world underwater for up to four months without resurfacing.

Construction of the Nautilus was made possible by the successful development of a nuclear propulsion plant by a group of scientists and engineers at the Naval Reactors Branch of the Atomic Energy Commission. In July 1951, the US Congress authorized construction of the world's first nuclear-powered submarine, under the leadership of Captain Hyman G. Rickover, USN.[3] Admiral Rickover came up with the idea of nuclear submarines.

The Westinghouse Corporation was assigned to build its reactor. After the submarine was completed, President Harry S. Truman broke the traditional bottle of champagne on Nautilus' bow. On January 17, 1955, it began its sea trials after leaving its dock in Groton, Connecticut. The submarine was 320 feet long, and cost about $55 million.

The Soviet Union soon followed the United States in developing nuclear-powered submarines in the 1950s. Stimulated by the US development of the Nautilus, Soviet work on nuclear propulsion reactors began in the early 1950s at the Institute of Physics and Power Engineering, in Obninsk, under Anatoliy P. Alexandrov, later to become head of the Kurchatov Institute. In 1956, the first Soviet propulsion reactor designed by his team began operational testing. Meanwhile, a design team under Vladimir N. Peregudov worked on the vessel that would house the reactor.

After overcoming many obstacles, including steam generation problems, radiation leaks, and other difficulties, the first nuclear submarine based on these combined efforts entered service in the Soviet Navy in 1958.[4]

At the height of the Cold War, approximately five to ten nuclear submarines were being commissioned from each of the four Soviet submarine yards (Sevmash in Severodvinsk, Admiralteyskiye Verfi in St. Petersburg, Krasnoye Sormovo in Nizhny Novgorod, and Amurskiy Zavod in Komsomolsk-on-Amur).[5]

late 1950s through the end of 1997, the Soviet Union, and later Russia, built a total of 245 nuclear submarines, more than all other nations combined[6].

In the 20th century, both the United States (US) and the Soviet Union (USSR) were pursuing technologies to build nuclear submarines to overcome the limitations of conventional submarines. Nuclear-powered submarines are one of the most potent symbols of the bygone U.S.-Soviet arms race.

Today, six countries deploy some form of nuclear-powered strategic submarines: the United States, Russia, France, the United Kingdom, People's Republic of China, and India.[7] Several other countries, including Argentina and Brazil,[8][9] have ongoing projects in different phases to build nuclear-powered submarines.

In the United Kingdom, all former and current nuclear submarines for the Royal Navy have been constructed in Barrow-in-Furness (at BAE Systems Submarine Solutions or its predecessor VSEL).


The main difference between conventional submarines and nuclear submarines is the power generation system. Nuclear submarines employ nuclear reactors for this task. They either generate electricity that powers electric motors connected to the propeller shaft or rely on the reactor heat to produce steam that drives steam turbines (cf. nuclear marine propulsion). Reactors used in submarines typically use highly enriched fuel (often greater than 20%) to enable them to deliver a large amount of energy from a smaller reactor.

The nuclear reactor also supplies energy to the submarine's other subsystems, such as for maintenance of air quality, fresh water production by distilling salt water from the ocean, temperature regulation, etc. All naval nuclear reactors currently in use are operated with diesel generators as a backup power system. These engines are able to provide emergency electrical power for reactor decay heat removal as well as enough electric power to supply an emergency propulsion mechanism. Submarines may carry nuclear fuel for up to 30 years of operation. The only resource that limits the time underwater is the food supply for the crew and maintenance of the vessel.


United States Navy

First Generation

Second Generation

Third Generation

Fourth Generation

Soviet Navy/Russian Navy

First Generation

Second Generation

  • Project 661 (Papa) attack submarines
  • Project 667 (Yankee) ballistic missile submarines
  • Project 667B (Delta) ballistic missile submarines
  • Project 670 (Charlie) cruise missile submarines
  • Project 671 (Victor) attack submarines

Third Generation

  • Project 678 (X-Ray) research submersible
  • Project 685 (Mike) attack submarine K-278 Komsomolets
  • Project 705 (Alfa) attack submarines
  • Project 941 (Typhoon) ballistic missile submarines
  • Project 945 (Sierra) attack submarines
  • Project 949 (Oscar) cruise missile submarines
  • Project 1910 (Uniform) special purpose submarines

Fourth Generation

  • Project 885 (Graney) attack submarines
  • Project 935 (Borei) ballistic missile submarines
  • Project 971 (Akula) attack submarines

Royal Navy

First Generation

Second Generation

Third Generation

French Navy

First Generation

Second Generation

People's Liberation Army Navy (PLAN) of the People's Republic of China

First Generation

  • Type 091 (Han) attack submarines
  • Type 092 (Xian) ballistic missile submarines

Second Generation

  • Type 093 (Shang) attack submarines
  • Type 094 (Jin) ballistic missile submarines

Third Generation

  • Type 095 attack submarines
  • Type 096 (Tang) ballistic missile submarines

Indian Navy


Nuclear powered submarines have suffered a number of accidents (not all related to the power supply).

  • K-19, 1961, the reactor almost had a meltdown and exploded. Several of the crew died of radiation exposure. The events on board the submarine are dramatized by the film K-19: The Widowmaker.
  • USS Thresher (SSN-593), 1963, was lost during deep diving tests and later investigation concluded that failure of a brazed pipe joint and ice formation in the ballast blow valves prevented surfacing. The accident motivated a number of safety changes to the US fleet.
  • K-27, 1968, experienced a near meltdown of one of its liquid metal (lead-bismuth) cooled VT-1 reactors, caing the shiptobe deactivated by 20 July 1968.
  • K-219, 1986, the reactor almost had a meltdown. Sergei Preminin died after he manually lowered the control rods, and stopped the explosion. The submarine sank three days later.
  • K-141 Kursk, 2000, the generally accepted theory is that a leak of hydrogen peroxide in the forward torpedo room led to the detonation of a torpedo warhead, which in turn triggered the explosion of half a dozen other warheads about two minutes later.
  • HMS Vanguard & Le Triomphant, February 2009, the French and British submarines collided in the Atlantic while on routine patrols. There were no injuries among the crews, but both ships were damaged during the collision. The chair of the Campaign for Nuclear Disarmament, Kate Hudson, said "the dents reportedly visible on the British sub show the boats were no more than a couple of seconds away from total catastrophe."[10]


  • Ballistic missile submarine
  • List of nuclear submarines
  • Submarine


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