| Nuclear submarine | |
|---|---|
 BritishAstute-class submarine | |
| Classification | Watercraft |
| Industry | Arms |
| Application | Underwater warfare |
| Invented | 1955 (70 years ago) (1955)[1] |
Anuclear submarine is asubmarine powered by anuclear reactor, but not necessarilynuclear-armed.
Nuclear submarines have considerable performance advantages over "conventional" (typicallydiesel-electric) 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 betweenrefuelings grants a virtually unlimited range, making the only limits on voyage times factors such as the need to restock food or other consumables.[2] Thusnuclear propulsion solves the problem of limited mission duration that all electric (battery orfuel cell powered) submarines face.
The high cost of nuclear technology means that relatively few of the world's military powers have fielded nuclear submarines. Radiation incidents have occurred within the Soviet submarines, includingserious nuclear and radiation accidents, but American naval reactors starting with theS1W and subsequent designs have operated without incident since the launch ofUSSNautilus (SSN-571) in 1954.[3][4]
In the USclassification, nuclear-powered submarines are designated as SSxN, where the SS denotes submarine, x=G means that thesubmarine is equipped withguided missiles (usuallycruise missiles), x=B means that thesubmarine is equipped withballistic missiles (usuallyintercontinental) and the N means that the submarine is nuclear-powered. SSN refers to nuclear-poweredattack submarines, which do not carry missiles.[5]
The idea for a nuclear-powered submarine was first proposed in theUnited States Navy by theNaval Research Laboratory's physicistRoss Gunn in 1939.[6] TheRoyal Navy began researching designs fornuclear propulsion plants in 1946.[7]
Construction of the world's first nuclear-powered submarine was made possible by the successful development of a nuclear propulsion plant by a group of scientists and engineers in the United States at theNaval Reactors Branch of theBureau of Ships and theAtomic Energy Commission. In July 1951, theU.S. Congress authorized construction of the first nuclear-powered submarine,Nautilus, under the leadership ofCaptain Hyman G. Rickover, USN (sharing a name withCaptain Nemo's fictional submarineNautilus inJules Verne's 1870 novelTwenty Thousand Leagues Under the Seas, the first demonstrably practical submarineNautilus, and anotherUSS Nautilus (SS-168) that served with distinction inWorld War II).[citation needed]
TheWestinghouse Corporation was assigned to build its reactor. After the submarine was completed at theElectric Boat Company, First LadyMamie Eisenhower broke thetraditional bottle of champagne onNautilus' bow, and the submarine wascommissionedUSS Nautilus (SSN-571), on 30 September 1954.[8] On 17 January 1955, she departedGroton, Connecticut, to beginsea trials. The submarine was 320 feet (98 m) long and cost about $55 million. Recognizing the utility of such vessels, the BritishAdmiralty formed plans to build nuclear-powered submarines.[9]
TheSoviet Union soon followed the United States in developing nuclear-powered submarines in the 1950s. Stimulated by the U.S. development ofNautilus, Soviets began work on nuclear propulsion reactors in the early 1950s at theInstitute of Physics and Power Engineering, inObninsk, under Anatoliy P. Alexandrov, later to become head of theKurchatov 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, includingsteam generation problems,radiation leaks, and other difficulties, the first nuclear submarine based on these combined efforts,K-3Leninskiy Komsomol of the Project 627Kit class, called aNovember-class submarine byNATO, entered service in theSoviet Navy in 1958.[10]
TheUnited Kingdom's first nuclear-powered submarineHMS Dreadnought was fitted with an AmericanS5W reactor, provided to Britain under the1958 US-UK Mutual Defence Agreement. The hull and combat systems ofDreadnought were of British design and construction, although the hull form and construction practices were influenced by access to American designs.[7] DuringDreadnought's construction,Rolls-Royce, in collaboration with theUnited Kingdom Atomic Energy Authority at the Admiralty Research Station,HMSVulcan, atDounreay, developed a completely new British nuclear propulsion system. In 1960, the UK's second nuclear-powered submarine was ordered fromVickers Armstrong and, fitted withRolls-Royce's PWR1 nuclear plant,HMS Valiant was the first all-British nuclear submarine.[11] Further technology transfers from the United States made Rolls-Royce entirely self-sufficient in reactor design in exchange for a "considerable amount" of information regarding submarine design and quietening techniques transferred from the United Kingdom to the United States.[12][13] The rafting system for theValiant class provided the Royal Navy with an advantage in submarine silencing that the United States Navy did not introduce until considerably later.[14]
Nuclear power proved ideal for the propulsion of strategicballistic missile submarines (SSB), greatly improving their ability to remain submerged and undetected. The world's first operational nuclear-powered ballistic missile submarine (SSBN) wasUSS George Washington with 16Polaris A-1 missiles, which conducted the first SSBN deterrent patrol November 1960 – January 1961. The Soviets already had several SSBs of theProject 629 (Golf class) and were only a year behind the US with their first SSBN,ill-fatedK-19 ofProject 658 (Hotel class), commissioned in November 1960. However, this class carried the same three-missile armament as the Golfs. The first Soviet SSBN with 16 missiles was theProject 667A (Yankee class), the first of which entered service in 1967, by which time the US had commissioned 41 SSBNs, nicknamed the "41 for Freedom".[15][16]
At the height of theCold War, approximately five to ten nuclear submarines were being commissioned yearly from the four Soviet submarine yards (Sevmash inSeverodvinsk,Admiralteyskiye Verfi in St. Petersburg,Krasnoye Sormovo inNizhny Novgorod, andAmurskiy Zavod inKomsomolsk-on-Amur). From the 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.[18]
Today, six countries deploy some form of nuclear-powered strategic submarines: the United States, Russia, the United Kingdom, France, China, and India.[19] Several other countries including Brazil and Australia[20][21] have ongoing projects in various phases to build nuclear-powered submarines.
In the United Kingdom, all former and current nuclear submarines of the BritishRoyal Navy (with the exception of three:HMS Conqueror,HMS Renown andHMS Revenge) have been constructed inBarrow-in-Furness (atBAE Systems Submarine Solutions or its predecessorVSEL) where construction of nuclear submarines continues.Conqueror is[update] the only nuclear-powered submarine in the world ever to have engaged an enemy ship with torpedoes, sinking the cruiserARA General Belgrano with twoMark 8 torpedoes during the 1982Falklands War.
The main difference between conventional submarines and nuclear submarines is thepower generation system. Nuclear submarines employnuclear reactors for this task. They either generate electricity that powerselectric motors connected to thepropellershaft or rely on the reactor's heat to producesteam that drivessteam turbines (cf.nuclear marine propulsion). Reactors used in submarines typically usehighly enrichedfuel (often greater than 20%) to enable them to deliver a large amount of power from a smaller reactor and operate longer between refuelings – which are difficult due to the reactor's position within the submarine's pressure hull. Also, virtually all nuclear reactors employed in submarines so far have been of thepressurized light-water reactor type.[22]
The nuclear reactor also supplies power 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 withdiesel generators as a backup power system. These engines are able to provide emergency electrical power for reactordecay 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.
Thestealth technology weakness of nuclear submarines is the need to cool the reactor even when the submarine is not moving; about 70% of the reactor output heat is dissipated into the sea water. This leaves a "thermal wake", a plume of warm water of lower density which ascends to the sea surface and creates a "thermal scar" that is observable bythermal imaging systems, e.g.,FLIR.[23] Another problem is that the reactor is always running, creating steam noise, which can be heard onsonar, and the reactor pump (used to circulate reactor coolant), also creates noise, as opposed to a conventional submarine, which can move about on almost silent electric motors.[citation needed]
The useful lifetime of a nuclear submarine is estimated to be approximately 25 to 30 years, after this period the submarine will face fatigue and corrosion of components, obsolescence and escalating operating costs.[24][25] The decommissioning of these submarines is a long process; some are held in reserve ormothballed for some time and eventually scrapped, others are disposed of immediately.[26][25] Countries operating nuclear submarines have different strategies when it comes to decommissioning nuclear submarines.[27] Nonetheless, the effective disposal of nuclear submarines is costly, in 2004 it was estimated to cost around 4 billion dollars.[28][29]
Generally there are two options when it comes to decommissioning nuclear submarines. The first option is to defuel the nuclear reactor and remove the material and components that contain radioactivity, after which the hull section containing the nuclear reactor will then be cut out of the submarine and transported to a disposal site for low-level radioactive waste and get buried according to waste procedures.[25] The second option is to defuel the nuclear reactor, disassemble the submarine propulsion plant, install vents in the nonreactor compartments and fill the reactor compartment.[24][25] After sealing the submarine it can then be towed to a designated deep-sea disposal site, be flooded and settle intact on the sea floor.[25] This last option has been considered by some navies and countries in the past.[30] However, while sea disposal is cheaper than land disposal the uncertainty regarding regulations and international law, such as theLondon Dumping Convention and theLaw of the Sea Convention, has stopped them from proceeding with this option.[30]
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Source:[34]
Some of the most seriousnuclear and radiation accidents by death toll in the world have involved nuclear submarine mishaps. To date, all of these were units of the formerSoviet Union.[3][4][45] Reactor accidents that resulted in core damage and release of radioactivity from nuclear-powered submarines include:[3][46]
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It has been reported that in 2027 the Russian Navy plans to introduce a nuclear-powered and nuclear-armedunmanned underwater vehicle namedPoseidon.[53][54] Limited data available in open literature suggests that it uses a small (mostly likelyenriched uranium-fueled) reactor and is capable or travelling at a maximum high speed of 130 km/h. It is expected to be launched from specially designedBelgorod class submarines and to hit large coastal cities as asecond strike weapon. (Although the initial tests of Poseidon were conducted with a diesel-electric submarineSarov). The main advantage of usingunmanned underwater vehicles instead ofSSBNs as a second strike weapon is to prevent the loss of lives of the SSBN crew. If the second strike nuclear missiles are launched directly from an SSBN, the location of the submarine is revealed and it can be quickly destroyed in a third strike by acruise orballistic missile, launched from another submarine, from a surface ship or from land. When anUUV delivers a nuclear charge, the location of the mothership remains unknown, and the ship is likely to survive the 3rd strike. No other country is known to be developing similar weapons in 2024.[22]
In the meantime, theUnited States is developingColumbia-class submarines. It is expected to have 16 missile tubes and to have its first patrol mission in 2031. Twelve submarines of this class, with a service life of ca. 42 years, are expected to be commissioned.[31]
the British made important contributions to U.S. submarine design, such as the concept of rafting for silencing and initial types of pump-jets
Current and planned classes of nuclear-powered attack submarines | |
|---|---|
 Royal Australian Navy | |
 Brazilian Navy |
|
 People's Liberation Army Navy |
|
 French Navy | |
 Indian Navy |
|
 Russian Navy | |
 Royal Navy | |
 United States Navy |
|
SSBN classes in service | |
|---|---|
| People's Liberation Army Navy | |
| French Navy | |
| Indian Navy | |
| Russian Navy | |
| Royal Navy | |
| United States Navy | |
| International | |
|---|---|
| National | |
| Other | |
