An SSN is a nuclear-powered general-purpose attack submarine. SSN is the US Navy hull classification symbol for such vessels; the SS denotes a submarine [1] and the N denotes nuclear power. The designation SSN is used for interoperability throughout NATO under STANAG 1166, [2] though navies use other terms.
The first nuclear-powered attack submarine was the US Navy's USS Nautilus, operational from 1954. This was followed by the four submarines of the Skate class entering service in 1957. The Royal Navy's first nuclear fleet submarine was HMS Dreadnought which by using an American reactor entered service in 1963. The first all-British nuclear submarines were the two Valiant-class submarines.
The USN submarine fleet has been all-nuclear powered for over two decades. The bulk of the USN's SSN fleet has been the Los Angeles-class attack submarine. Designed during the Cold War the Los Angeles-class boats'raison d'etre was to protect USN carrier battle groups and to hunt Soviet Navy SSBNs before they could launch a first strike against the United States.
The first ever major combat action involving an SSN was during the 1982 Falklands War. An Argentinian cruiser, ARA General Belgrano was sunk by torpedoes fired by the Royal Navy fleet submarine HMS Conqueror. After that incident, the Argentinian Navy was effectively confined to port.
Since the end of the Cold War, SSNs have evolved into multi-mission submarines. Their roles include submarine-launched cruise missile platforms, intelligence gathering platforms, insertion and exfiltration of special forces teams in addition to traditional hunter-killer SSN roles.
The advantages of an SSN over a conventionally powered SSK are much longer endurance (limited more by the crew than the boat, a nuclear submarine can stay submerged for months and does not need refueling in their 25-year lifespans), and higher speed. Unlike most SSKs, SSNs do not have to surface periodically for air, which would compromise their stealth. Some of the newest conventional submarines approach these advantages: Stirling engine powered vessels can cruise underwater for up to two weeks and, like diesel/electric vessels (and in theory LOX powered vessels), are significantly quieter than nuclear submarines, since they do not need to run the powerful (and noisy) pumps associated with the cooling circuits of pressurized water reactors.
The main disadvantages of an SSN are the technological challenges and expenses of building and maintaining a nuclear power plant. Nuclear submarines can have political downsides, as some countries refuse to accept nuclear-powered vessels as a matter of policy. Furthermore, decommissioned nuclear submarines require costly dismantling and long term storage of the radioactive waste.
The following navies currently operate SSNs:
Royal Australian Navy 
Brazilian Navy 
People's Liberation Army Navy of the People's Republic of China
French Navy 
Indian Navy 
Russian Navy 
Royal Navy of the United Kingdom(Known as "fleet submarines" in the Royal Navy.)
United States Navy Indian Navy Royal Navy of the United Kingdom
Soviet / Russian Navy United States Navy The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration (NOAA) use a hull classification symbol to identify their ships by type and by individual ship within a type. The system is analogous to the pennant number system that the Royal Navy and other European and Commonwealth navies use.
The Seawolf class is a class of nuclear-powered, fast attack submarines (SSN) in service with the United States Navy. The class was the intended successor to the Los Angeles class, and design work began in 1983. A fleet of 29 submarines was to be built over a ten-year period, but that was reduced to 12 submarines. The end of the Cold War and budget constraints led to the cancellation of any further additions to the fleet in 1995, leaving the Seawolf class limited to just three boats. This, in turn, led to the design of the smaller Virginia class. The Seawolf class cost about $3 billion per unit, making it the most expensive United States Navy fast attack submarine and second most expensive submarine ever, after the French Triomphant-class nuclear-powered ballistic missile submarines.
The Ship-Submarine Recycling Program (SRP) is the process that the United States Navy uses to dispose of decommissioned nuclear vessels. SRP takes place only at the Puget Sound Naval Shipyard (PSNS) in Bremerton, Washington, but the preparations can begin elsewhere.
The Virginia class, or the SSN-774 class, is the latest class of nuclear-powered cruise missile fast-attack submarines in service with the United States Navy. Designed by General Dynamics Electric Boat (EB) and Huntington Ingalls Industries, the Virginia class incorporates the latest in stealth, intelligence gathering, and weapons systems.
A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. These submarines became a major weapon system in the Cold War because of their nuclear deterrence capability. They can fire missiles thousands of kilometers from their targets, and acoustic quieting makes them difficult to detect, thus making them a survivable deterrent in the event of a first strike and a key element of the mutual assured destruction policy of nuclear deterrence.
An attack submarine or hunter-killer submarine is a submarine specifically designed for the purpose of attacking and sinking other submarines, surface combatants and merchant vessels. In the Soviet and Russian navies they were and are called "multi-purpose submarines". They are also used to protect friendly surface combatants and missile submarines. Some attack subs are also armed with cruise missiles, increasing the scope of their potential missions to include land targets.
USS Nautilus (SSN-571) was the world's first operational nuclear-powered submarine and the first submarine to complete a submerged transit of the North Pole on 3 August 1958. Her initial commanding officer was Eugene "Dennis" Wilkinson, a widely respected naval officer who set the stage for many of the protocols of today's Nuclear Navy of the US, and who had a storied career during military service and afterwards.
The Victor class, Soviet designations Project 671 Yorsh, Project 671RT Syomga and Project 671RTM/RTMK Shchuka,, are series of nuclear-powered attack submarines built in the Soviet Union and operated by the Soviet Navy. Since the 1960s, 48 units were built in total, of which the last remaining are currently in service with the Russian Navy. The Victor-class submarines featured a teardrop shape, allowing them to travel at high speed. These vessels were primarily designed to protect Soviet surface fleets and to attack American ballistic missile submarines. Project 671 began in 1959 with the design task assigned to SKB-143.
A nuclear submarine is a submarine powered by a nuclear reactor, but not necessarily nuclear-armed. Nuclear submarines have considerable performance advantages over "conventional" submarines. 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, 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.
The Akula class, Soviet designation Project 971 Shchuka-B is a series of fourth generation nuclear-powered attack submarines (SSNs) first deployed by the Soviet Navy in 1986. There are four sub-classes or flights of Shchuka-B, consisting of the original seven Project 971 boats, commissioned between 1984 and 1990; six Project 971Is, commissioned between 1991 and 2009; one Project 971U, commissioned in 1995; and one Project 971M, commissioned in 2001. The Russians call all of the submarines Shchuka-B, regardless of modifications.
Nuclear marine propulsion is propulsion of a ship or submarine with heat provided by a nuclear reactor. The power plant heats water to produce steam for a turbine used to turn the ship's propeller through a gearbox or through an electric generator and motor. Nuclear propulsion is used primarily within naval warships such as nuclear submarines and supercarriers. A small number of experimental civil nuclear ships have been built.
A nuclear navy, or nuclear-powered navy, refers to the portion of a navy consisting of naval ships powered by nuclear marine propulsion. The concept was revolutionary for naval warfare when first proposed. Prior to nuclear power, submarines were powered by diesel engines and could only submerge through the use of batteries. In order for these submarines to run their diesel engines and charge their batteries they would have to surface or snorkel. The use of nuclear power allowed these submarines to become true submersibles and unlike their conventional counterparts, they became limited only by crew endurance and supplies.
The names of commissioned ships of the United States Navy all start with USS, for United States Ship. Non-commissioned, primarily civilian-crewed vessels of the U.S. Navy under the Military Sealift Command have names that begin with USNS, standing for United States Naval Ship. A letter-based hull classification symbol is used to designate a vessel's type. The names of ships are selected by the Secretary of the Navy. The names are those of states, cities, towns, important persons, important locations, famous battles, fish, and ideals. Usually, different types of ships have names originated from different types of sources.
The Royal Navy Submarine Service is one of the five fighting arms of the Royal Navy. It is sometimes known as the Silent Service, as submarines are generally required to operate undetected.
United States ship naming conventions for the U.S. Navy were established by congressional action at least as early as 1862. Title 13, section 1531, of the U.S. Code, enacted in that year, reads, in part,
The vessels of the Navy shall be named by the Secretary of the Navy under direction of the President according to the following rule: Sailing-vessels of the first class shall be named after the States of the Union, those of the second class after the rivers, those of the third class after the principal cities and towns and those of the fourth class as the President may direct.
Nerpa is a 8,140-tonne (8,010-long-ton) Project 971 nuclear-powered attack submarine. The construction of the submarine was started in Russia in 1993, but was suspended due to lack of funding. India then sponsored further construction and sea trials of the submarine provided it was leased to the Indian Navy for 10 years. It was launched as K-152 Nerpa in October 2008 and entered service with the Russian Navy in late 2009. The submarine was leased to the Indian Navy in 2011 after extensive trials, and was formally commissioned into service as INS Chakra with the Eastern Naval Command at a ceremony in Visakhapatnam on 4 April 2012. In June 2021 Chakra was spotted on the surface escorted by Indian and Russian warships in the Singapore Strait while presumably heading towards the Russian naval base in Vladivostok; some media speculated that she was returning to Russia before the expiry of the lease term.
The K-152 Nerpa accident occurred aboard the Russian submarine K-152 Nerpa on 8 November 2008, which resulted in the deaths of 20 people and injuries to 41 more. The accident was blamed on a crew member who was allegedly playing with a fire suppressant system that he thought was not operative.
The Indian Navy aims to procure new nuclear-powered attack submarines under Project 75 Alpha. The Government of India approved the construction of six of such submarines in February 2015. These will be designed by the Navy's in-house Directorate of Naval Design and built in India at the Shipbuilding Centre at Visakhapatnam. The construction is expected to commence on 2023-24 while the first submarine is expected to enter service in 2032.
The SSN-AUKUS, also known as the SSN-A, is a planned class of nuclear-powered fleet submarine (SSN) intended to enter service with the United Kingdom's Royal Navy in the late 2030s and Royal Australian Navy in the 2040s. The class will replace the UK's Astute class and Australia's Collins class submarines.
{{cite web}}: CS1 maint: archived copy as title (link){{cite web}}: CS1 maint: multiple names: authors list (link)Current and planned classes of nuclear-powered attack submarines | |
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 Royal Australian Navy |
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 People's Liberation Army Navy |
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 French Navy | |
 Indian Navy |
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 Russian Navy |
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 Royal Navy | |
 United States Navy |
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