fbpx
Wikipedia

Nuclear marine propulsion

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.[1]

When the nuclear-powered Arktika class 50 Let Pobedy was put into service in 2007, it became the world's largest icebreaker.

Compared to oil- or coal-fuelled ships, nuclear propulsion offers the advantage of very long intervals of operation before refueling. All the fuel is contained within the nuclear reactor, so no cargo or supplies space is taken up by fuel, nor is space taken up by exhaust stacks or combustion air intakes.[2] The low fuel cost is offset by high operating costs and investment in infrastructure however, so nearly all nuclear-powered vessels are military.[2]

Power plants edit

Basic operation of naval ship or submarine edit

Most naval nuclear reactors are of the pressurized water type, with the exception of a few[quantify] attempts[by whom?] at using liquid sodium-cooled reactors.[2] A primary water circuit transfers heat generated from nuclear fission in the fuel to a steam generator; this water is kept under pressure so it does not boil. This circuit operates at a temperature of around 250 to 300 °C (482 to 572 °F). Any radioactive contamination in the primary water is confined. Water is circulated by pumps; at lower power levels, reactors designed for submarines may rely on natural circulation of the water to reduce noise generated by the pumps.[citation needed]

The hot water from the reactor heats a separate water circuit in the steam generator. That water is converted to steam and passes through steam driers on its way to the steam turbine. Spent steam at low pressure runs through a condenser cooled by seawater and returns to liquid form. The water is pumped back to the steam generator and continues the cycle. Any water lost in the process can be made up by desalinated sea water added to the steam generator feed water.[3]

In the turbine, the steam expands and reduces its pressure as it imparts energy to the rotating blades of the turbine. There may be many stages of rotating blades and fixed guide vanes. The output shaft of the turbine may be connected to a gearbox to reduce rotation speed, then a shaft connects to the vessel's propellers. In another form of drive system, the turbine turns an electrical generator, and the electric power produced is fed to one or more drive motors for the vessel's propellers. The Russian, U.S. and British navies rely on direct steam turbine propulsion, while French and Chinese ships use the turbine to generate electricity for propulsion (turbo-electric transmission).[citation needed]

Some nuclear submarines have a single reactor, but Russian submarines have two, and so had USS Triton. Most American aircraft carriers are powered by two reactors, but USS Enterprise had eight. The majority of marine reactors are of the pressurized water type, although the U.S. and Soviet navies have designed warships powered with liquid metal cooled reactors.[citation needed]

Differences from land power plants edit

Marine-type reactors differ from land-based commercial electric power reactors in several respects.[citation needed]

While land-based reactors in nuclear power plants produce up to around 1600 megawatts of net electrical power (the nameplate capacity of the EPR), a typical marine propulsion reactor produces no more than a few hundred megawatts. Some small modular reactors (SMR) are similar to marine propulsion reactors in capacity and some design considerations and thus nuclear marine propulsion (whether civilian or military) is sometimes proposed as an additional market niche for SMRs. Unlike for land-based applications where hundreds of hectares can be occupied by installations like Bruce Nuclear Generating Station, at sea tight space limits dictate that a marine reactor must be physically small, so it must generate higher power per unit of space. This means its components are subject to greater stresses than those of a land-based reactor. Its mechanical systems must operate flawlessly under the adverse conditions encountered at sea, including vibration and the pitching and rolling of a ship operating in rough seas. Reactor shutdown mechanisms cannot rely on gravity to drop control rods into place as in a land-based reactor that always remains upright. Salt water corrosion is an additional problem that complicates maintenance.[citation needed]

 
A nuclear fuel element for the cargo ship NS Savannah. The element contains four bundles of 41 fuel rods. The uranium oxide is enriched to 4.2 and 4.6 percent U-235

As the core of a seagoing reactor is much smaller than a power reactor, the probability of a neutron intersecting with a fissionable nucleus before it escapes into the shielding is much lower. As such, the fuel is typically more highly enriched (i.e., contains a higher concentration of 235U vs. 238U) than that used in a land-based nuclear power plant, which increases the probability of fission to the level where a sustained reaction can occur. Some marine reactors run on relatively low-enriched uranium, which requires more frequent refueling. Others run on highly enriched uranium, varying from 20% 235U, to the over 96% 235U found in U.S. submarines,[4] in which the resulting smaller core is quieter in operation (a big advantage to a submarine).[5] Using more-highly enriched fuel also increases the reactor's power density and extends the usable life of the nuclear fuel load, but is more expensive and a greater risk to nuclear proliferation than less-highly enriched fuel.[6]

A marine nuclear propulsion plant must be designed to be highly reliable and self-sufficient, requiring minimal maintenance and repairs, which might have to be undertaken many thousands of miles from its home port. One of the technical difficulties in designing fuel elements for a seagoing nuclear reactor is the creation of fuel elements that will withstand a large amount of radiation damage. Fuel elements may crack over time and gas bubbles may form. The fuel used in marine reactors is a metal-zirconium alloy rather than the ceramic UO2 (uranium dioxide) often used in land-based reactors. Marine reactors are designed for long core life, enabled by the relatively high enrichment of the uranium and by incorporating a "burnable poison" in the fuel elements, which is slowly depleted as the fuel elements age and become less reactive. The gradual dissipation of the "nuclear poison" increases the reactivity of the core to compensate for the lessening reactivity of the aging fuel elements, thereby extending the usable life of the fuel. The compact reactor pressure vessel is provided with an internal neutron shield, which reduces the damage to the steel from constant neutron bombardment.[citation needed]

Decommissioning edit

Decommissioning nuclear-powered submarines has become a major task for U.S. and Russian navies. After defuelling, U.S. practice is to cut the reactor section from the vessel for disposal in shallow land burial as low-level waste (see the ship-submarine recycling program). In Russia, whole vessels, or sealed reactor sections, typically remain stored afloat, although a new facility near Sayda Bay is to provide storage in a concrete-floored facility on land for some submarines in the far north.[citation needed]

Future designs edit

Russia built a floating nuclear power plant for its far eastern territories. The design has two 35 MWe units based on the KLT-40 reactor used in icebreakers (with refueling every four years). Some Russian naval vessels have been used to supply electricity for domestic and industrial use in remote far eastern and Siberian towns.[citation needed]

In 2010, Lloyd's Register was investigating the possibility of civilian nuclear marine propulsion and rewriting draft rules (see text under Merchant Ships).[7][8][9]

Civil liability edit

Insurance of nuclear vessels is not like the insurance of conventional ships. The consequences of an accident could span national boundaries, and the magnitude of possible damage is beyond the capacity of private insurers.[10] A special international agreement, the Brussels Convention on the Liability of Operators of Nuclear Ships, developed in 1962, would have made signatory national governments liable for accidents caused by nuclear vessels under their flag[11] but was never ratified owing to disagreement on the inclusion of warships under the convention.[12] Nuclear reactors under United States jurisdiction are insured by the provisions of the Price–Anderson Act.[citation needed]

Military nuclear ships edit

 
In addition to nuclear-powered aircraft carriers, the United States once operated nuclear-powered cruisers.

By 1990, there were more nuclear reactors powering ships (mostly military) than there were generating electric power in commercial power plants worldwide.[13]

Under the direction of U.S. Navy Captain (later Admiral) Hyman G. Rickover,[14] the design, development and production of nuclear marine propulsion plants started in the United States in the 1940s. The first prototype naval reactor was constructed and tested at the Naval Reactor Facility at the National Reactor Testing Station in Idaho (now called the Idaho National Laboratory) in 1953.

Submarines edit

 
The nuclear-propelled French submarine Saphir returning to Toulon, its home port, after Mission Héraclès

The first nuclear submarine, USS Nautilus (SSN-571), put to sea in 1955 (SS was a traditional hull classification symbol for U.S. submarines, while SSN denoted the first "nuclear" submarine).[15]

The Soviet Union also developed nuclear submarines. The first types developed were the Project 627, NATO-designated November class with two water-cooled reactors, the first of which, K-3 Leninsky Komsomol, was underway under nuclear power in 1958.[16]

Nuclear power revolutionized the submarine, finally making it a true "underwater" vessel, rather than a "submersible" craft, which could only stay underwater for limited periods. It gave the submarine the ability to operate submerged at high speeds, comparable to those of surface vessels, for unlimited periods, dependent only on the endurance of its crew. To demonstrate this USS Triton was the first vessel to execute a submerged circumnavigation of the Earth (Operation Sandblast), doing so in 1960.[17]

Nautilus, with a pressurized water reactor (PWR), led to the parallel development of other submarines like a unique liquid metal cooled (sodium) reactor in USS Seawolf, or two reactors in Triton, and then the Skate-class submarines, powered by single reactors, and a cruiser, USS Long Beach, in 1961, powered by two reactors.[citation needed]

By 1962, the United States Navy had 26 operational nuclear submarines and another 30 under construction. Nuclear power had revolutionized the Navy. The United States shared its technology with the United Kingdom, while French, Soviet, Indian and Chinese development proceeded separately.[citation needed]

After the Skate-class vessels, U.S. submarines were powered by a series of standardized, single-reactor designs built by Westinghouse and General Electric. Rolls-Royce plc built similar units for Royal Navy submarines, eventually developing a modified version of their own, the PWR2.[citation needed]

The largest nuclear submarines ever built are the 26,500 tonne Russian Typhoon class. The smallest nuclear warships to date are the 2,700 tonne French Rubis-class attack submarines. The U.S. Navy operated an unarmed nuclear submarine, the NR-1 Deep Submergence Craft, between 1969 and 2008, which was not a combat vessel but was the smallest nuclear-powered submarine at 400 tons.[citation needed]

Aircraft carriers edit

The United States and France have built nuclear aircraft carriers.

French Navy edit

 
The aircraft carrier Charles de Gaulle of the French Navy

The sole French nuclear aircraft carrier example is Charles de Gaulle, commissioned in 2001 (a successor is planned).[18]

The French carrier is equipped with catapults and arresters. The Charles de Gaulle has 42,000 tonnes, is the flagship of the French Navy (Marine Nationale). The ship carries a complement of Dassault Rafale M and E‑2C Hawkeye aircraft, EC725 Caracal and AS532 Cougar helicopters for combat search and rescue, as well as modern electronics and Aster missiles.[19]

United States Navy edit

The United States Navy operates 11 carriers, all nuclear-powered:[20]

  • USS Enterprise: in service 1962–2012, powered by eight reactor units, is still the only aircraft carrier to house more than two nuclear reactors, with each A2W reactor taking the place of one of the conventional boilers in earlier constructions.[21]
  • Nimitz class: ten 101,000-ton, 1,092 ft long fleet carriers, the first of which was commissioned in 1975. A Nimitz-class carrier is powered by two nuclear reactors providing steam to four steam turbines.
  • Gerald R. Ford class, one 110,000-ton, 1,106 ft long fleet carrier. The lead of the class Gerald R. Ford, came into service in 2017, with another nine planned.

Destroyers and cruisers edit

Russian Navy edit

 
The Russian flagship Pyotr Veliky

The Kirov class, Soviet designation 'Project 1144 Orlan' (sea eagle), is a class of nuclear-powered guided-missile cruisers of the Soviet Navy and Russian Navy, the largest and heaviest surface combatant warships (i.e. not an aircraft carrier or amphibious assault ship) in operation in the world. Among modern warships, they are second in size only to large aircraft carriers, and of similar size to a World War II era battleships. The Soviet classification of the ship-type is "heavy nuclear-powered guided missile cruiser" (Russian: тяжёлый атомный ракетный крейсер). The ships are often referred to as battlecruisers by Western defence commentators due to their size and general appearance.[22]

United States Navy edit

The United States Navy at one time had nuclear-powered cruisers as part of its fleet. The first such ship was USS Long Beach (CGN-9). Commissioned in 1961, she was the world's first nuclear-powered surface combatant.[23] She was followed a year later by USS Bainbridge (DLGN-25). While Long Beach was designed and built as a cruiser,[24] Bainbridge began life as a frigate, though at that time the Navy was using the hull code "DLGN" for "destroyer leader, guided missile, nuclear".[25]

The last nuclear-powered cruisers the Americans would produce would be the four-ship Virginia class. USS Virginia (CGN-38) was commissioned in 1976, followed by USS Texas (CGN-39) in 1977, USS Mississippi (CGN-40) in 1978 and finally USS Arkansas (CGN-41) in 1980. Ultimately, all these ships proved to be too costly to maintain[26] and they were all retired between 1993 and 1999.[citation needed]

Other military ships edit

Communication and command ships edit

 
Command and communications ship SSV-33 Ural

SSV-33 Ural (ССВ-33 Урал; NATO reporting name: Kapusta [Russian for "cabbage"]) was a command and control naval ship operated by the Soviet Navy. SSV-33's hull was derived from that of the nuclear-powered Kirov-class battlecruisers with nuclear marine propulsion.[27] SSV-33 served in electronic intelligence, missile tracking, space tracking, and communications relay roles. Due to high operating costs, SSV-33 was laid up.[27]

SSV-33 carried only light defensive weapons. These were two AK-176 76 mm guns, four AK-630 30 mm guns, and four quadruple Igla missile mounts.[citation needed]

Nuclear-powered UUV edit

The Poseidon (Russian: Посейдон, "Poseidon", NATO reporting name Kanyon), previously known by Russian codename Status-6 (Russian: Статус-6), is a nuclear-powered and nuclear-armed unmanned underwater vehicle under development by Rubin Design Bureau, capable of delivering both conventional and nuclear payloads. According to Russian state TV, it is able to deliver a thermonuclear cobalt bomb of up to 200 megatonnes (four times as powerful as the most powerful device ever detonated, the Tsar Bomba, and twice its maximum theoretical yield) against an enemy's naval ports and coastal cities.[28]

Civilian nuclear ships edit

 
Engineer epaulette from Savannah

The following are ships that are or were in commercial or civilian use and have nuclear marine propulsion.

Merchant ships edit

Nuclear-powered civil merchant ships have not developed beyond a few experimental ships. The U.S.-built NS Savannah, completed in 1962, was primarily a demonstration of civil nuclear power and was too small and expensive to operate economically as a merchant ship. The design was too much of a compromise, being neither an efficient freighter nor a viable passenger liner. The German-built Otto Hahn, completed in 1968, a cargo ship and research facility, sailed some 650,000 nautical miles (1,200,000 km) on 126 voyages over 10 years without any technical problems.[citation needed] It proved too expensive to operate and was converted to diesel. The Japanese Mutsu, completed in 1972, was dogged by technical and political problems. Its reactor had significant radiation leakage and fishermen protested against the vessel's operation. All of these three ships used low-enriched uranium. Sevmorput, a Soviet and later Russian LASH carrier with icebreaking capability, has operated successfully on the Northern Sea Route since it was commissioned in 1988. As of 2021, it is the only nuclear-powered merchant ship in service.[citation needed]

Civilian nuclear ships suffer from the costs of specialized infrastructure. The Savannah was expensive to operate since it was the only vessel using its specialized nuclear shore staff and servicing facility. A larger fleet could share fixed costs among more operating vessels, reducing operating costs.

Despite this, there is still interest in nuclear propulsion. In November 2010 British Maritime Technology and Lloyd's Register embarked upon a two-year study with U.S.-based Hyperion Power Generation (now Gen4 Energy), and the Greek ship operator Enterprises Shipping and Trading SA to investigate the practical maritime applications for small modular reactors. The research intended to produce a concept tanker-ship design, based on a 70 MWt reactor such as Hyperion's. In response to its members' interest in nuclear propulsion, Lloyd's Register has also re-written its 'rules' for nuclear ships, which concern the integration of a reactor certified by a land-based regulator with the rest of the ship. The overall rationale of the rule-making process assumes that in contrast to the current marine industry practice where the designer/builder typically demonstrates compliance with regulatory requirements, in the future the nuclear regulators will wish to ensure that it is the operator of the nuclear plant that demonstrates safety in operation, in addition to the safety through design and construction. Nuclear ships are currently the responsibility of their own countries, but none are involved in international trade. As a result of this work in 2014 two papers on commercial nuclear marine propulsion were published by Lloyd's Register and the other members of this consortium.[8][9] These publications review past and recent work in the area of marine nuclear propulsion and describe a preliminary concept design study for a 155,000 DWT Suezmax tanker that is based on a conventional hull form with alternative arrangements for accommodating a 70 MWt nuclear propulsion plant delivering up to 23.5 MW shaft power at maximum continuous rating (average: 9.75 MW). The Gen4Energy power module is considered. This is a small fast-neutron reactor using lead–bismuth eutectic cooling and able to operate for ten full-power years before refueling, and in service last for a 25-year operational life of the vessel. They conclude that the concept is feasible, but further maturity of nuclear technology and the development and harmonisation of the regulatory framework would be necessary before the concept would be viable.[citation needed]

Nuclear propulsion has been proposed again on the wave of decarbonization of marine shipping, which accounts for 3–4% of global greenhouse gas emissions.[29]

Merchant cargo ships edit

  • USNS American Explorer; United States tanker, converted to conventional power while under construction
  • Mutsu, Japan (1970–1992); never carried commercial cargo, rebuilt as diesel engine powered RV Mirai in 1996
  • Otto Hahn, Germany (1968–1979); re-powered with diesel engine in 1979
  • NS Savannah, United States (1962–1972)
  • Sevmorput, Russia (1988–present), ice-strengthened nuclear-powered lighter aboard ship (LASH) carrier

In December 5, 2023, the Jiangnan Shipyard under the China State Shipbuilding Corporation officially released a design of a 24000 TEU-class container ship — known as the KUN-24AP — at Marintec China 2023, a premier maritime industry exhibition held in Shanghai. The container ship is reported to be powered by a thorium-based molten salt reactor, making it a first thorium-powered container ship and, if completed, the largest nuclear-powered container ship in the world.[30]

Icebreakers edit

Nuclear propulsion has proven both technically and economically feasible for nuclear-powered icebreakers in the Soviet, and later Russian, Arctic. Nuclear-fuelled ships operate for years without refueling, and the vessels have powerful engines, well-suited to the task of icebreaking.[citation needed]

The Soviet icebreaker Lenin was the world's first nuclear-powered surface vessel in 1959 and remained in service for 30 years (new reactors were fitted in 1970). It led to a series of larger icebreakers, the 23,500 ton Arktika class of six vessels, launched beginning in 1975. These vessels have two reactors and are used in deep Arctic waters. NS Arktika was the first surface vessel to reach the North Pole.[citation needed]

For use in shallow waters such as estuaries and rivers, shallow-draft, Taymyr-class icebreakers were built in Finland and then fitted with their single-reactor nuclear propulsion system in Russia. They were built to conform to international safety standards for nuclear vessels.[31]

All nuclear-powered icebreakers have been commissioned by the Soviet Union or Russia.[citation needed]

See also edit

References edit

  1. ^ Wirt, John G (1979). "A Federal Demonstration Project: N.S. Savannah". Innovation in the maritime industry. Vol. 1. National Academies, for Maritime Transportation Research Board, National Research Council (U.S.). pp. 29–36.
  2. ^ a b c Trakimavičius, Lukas. "The Future Role of Nuclear Propulsion in the Military" (PDF). NATO Energy Security Centre of Excellence. Retrieved 2021-10-15.
  3. ^ Viren Chopra, Rob Houston (ed), DK Eyewitness Books: Transportation, Penguin, 2012, ISBN 1465408894 page 60
  4. ^ Moltz, James Clay (March 2006). . NTI. Archived from the original on 2007-02-09. Retrieved 2007-03-07.
  5. ^ Acton, James (December 13, 2007). "Silence is highly enriched uranium". Retrieved 2007-12-13.
  6. ^ "Ending the Production of Highly Enriched Uranium for Naval Reactors" (PDF). James Martin Center for Nonproliferation Studies. Retrieved September 25, 2008.
  7. ^ "Full steam ahead for nuclear shipping", World Nuclear News, 18 November 2010, retrieved 27 November 2010.
  8. ^ a b Hirdaris, Spyros; Cheng, YF; Shallcross, P; Bonafoux, J; Carlson, D; Prince, B; Sarris, GA (15 March 2014). "Considerations on the potential use of Nuclear Small Modular Reactor (SMR) technology for merchant marine propulsion". Ocean Engineering. 79: 101–130. doi:10.1016/j.oceaneng.2013.10.015.
  9. ^ a b Hirdaris, Spyros; Cheng, YF; Shallcross, P; Bonafoux, J; Carlson, D; Prince, B; Sarris, GA (March 2014). "Concept Design for a Suezmax Tanker Powered by a 70 MW Small Modular Reactor". Transactions of the Royal Institution of Naval Architects Part A: International Journal of Maritime Engineering. 156 (A1): A37–A60. doi:10.3940/rina.ijme.2014.a1.276.
  10. ^ "Liability for Nuclear Damage". World Nuclear Association. Retrieved March 17, 2011.
  11. ^ "Brussels Convention on the Liability of Operators of Nuclear Ships". International Law. Public International Law. Retrieved March 17, 2011.
  12. ^ (PDF). International Atomic Energy Association. Archived from the original (PDF) on December 17, 2010. Retrieved March 17, 2011.
  13. ^ "Nuclear Weapons at Sea". Bulletin of the Atomic Scientists: 48–49. September 1990.
  14. ^ Groves, Leslie R.; Teller, Edward (1983). Now it can be told. p. 388. ISBN 978-0-306-80189-1.
  15. ^ Stacy, Susan (2000). Proving the Principle: A History of the Idaho National Engineering and Environmental Laboratory, 1949–1999. ISBN 978-0-16-059185-3.
  16. ^ Trakimavičius, Lukas. "Is Small Really Beautiful?The Future Role of Small Modular Nuclear Reactors (SMRs) In The Military" (PDF). NATO Energy Security Centre of Excellence. Retrieved 2020-12-05.
  17. ^ "First submarine circumnavigation". Guinness World Records. Retrieved 2020-06-02.
  18. ^ "Le programme du porte-avions qui remplacera le Charles-de-Gaulle est lancé". 23 October 2018.
  19. ^ Pike, John. "Charles de Gaulle". Global security. from the original on 10 November 2015. Retrieved 15 November 2015.
  20. ^ "Naval Vessel Register". Retrieved 2020-06-01.
  21. ^ "Speed Thrills III — Max speed of nuclear-powered aircraft carriers". Navweaps.com. 29 April 1999. Retrieved 20 April 2013.
  22. ^ Armi da guerra, De Agostini, Novara, 1985.
  23. ^ "USS Long Beach (CGN 9)".
  24. ^ John Pike. "CGN-9 Long Beach".
  25. ^ John Pike. "CGN 25 Bainbridge class". Global security.
  26. ^ "Nuclear power for surface combatants". Defense media network.
  27. ^ a b Pike, J. "SSV-33 Project 1941". GlobalSecurity.org. Retrieved 30 October 2015.
  28. ^ "Russian media: nuclear torpedo can destroy the US, Europe, the world". Business Insider.
  29. ^ "Shipping industry should consider nuclear option for decarbonizing: experts | S&P Global Platts". www.spglobal.com. 2020-11-04. Retrieved 2020-11-06.
  30. ^ Chen, Stephen (2023-12-05). "Chinese shipyard unveils plans for world's first nuclear container powered by cutting-edge molten salt reactor". South China Morning Post. Retrieved 2023-12-07.
  31. ^ Cleveland, Cutler J, ed. (2004). Encyclopedia of Energy. Vol. 1–6. Elsevier. pp. 336–340. ISBN 978-0-12-176480-7.
  32. ^ "На ледоколе 'Арктика' поднят российский флаг". sudostroenie.info (in Russian). 2020-10-21. Retrieved 2021-02-07.
  33. ^ "Nuclear-powered icebreaker Ural of Project 22220 leaves Murmansk for the first operational voyage". PortNews. 2 December 2022. Retrieved 4 December 2022.
  • AFP, 11 November 1998; in "Nuclear Submarines Provide Electricity for Siberian Town," FBIS-SOV-98-315, 11 November 1998.
  • ITAR-TASS, 11 November 1998; in "Russian Nuclear Subs Supply Electricity to Town in Far East," FBIS-SOV-98-316, 12 November 1998.
  • Harold Wilson's plan BBC News story

External links edit

  • The World Nuclear Association

nuclear, marine, propulsion, propulsion, ship, submarine, with, heat, provided, nuclear, reactor, power, plant, heats, water, produce, steam, turbine, used, turn, ship, propeller, through, gearbox, through, electric, generator, motor, nuclear, propulsion, used. 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 1 When the nuclear powered Arktika class 50 Let Pobedy was put into service in 2007 it became the world s largest icebreaker Compared to oil or coal fuelled ships nuclear propulsion offers the advantage of very long intervals of operation before refueling All the fuel is contained within the nuclear reactor so no cargo or supplies space is taken up by fuel nor is space taken up by exhaust stacks or combustion air intakes 2 The low fuel cost is offset by high operating costs and investment in infrastructure however so nearly all nuclear powered vessels are military 2 Contents 1 Power plants 1 1 Basic operation of naval ship or submarine 1 2 Differences from land power plants 2 Decommissioning 3 Future designs 4 Civil liability 5 Military nuclear ships 5 1 Submarines 5 2 Aircraft carriers 5 2 1 French Navy 5 2 2 United States Navy 5 3 Destroyers and cruisers 5 3 1 Russian Navy 5 3 2 United States Navy 5 4 Other military ships 5 5 Communication and command ships 5 6 Nuclear powered UUV 6 Civilian nuclear ships 6 1 Merchant ships 6 2 Merchant cargo ships 6 3 Icebreakers 7 See also 8 References 9 External linksPower plants editBasic operation of naval ship or submarine edit Most naval nuclear reactors are of the pressurized water type with the exception of a few quantify attempts by whom at using liquid sodium cooled reactors 2 A primary water circuit transfers heat generated from nuclear fission in the fuel to a steam generator this water is kept under pressure so it does not boil This circuit operates at a temperature of around 250 to 300 C 482 to 572 F Any radioactive contamination in the primary water is confined Water is circulated by pumps at lower power levels reactors designed for submarines may rely on natural circulation of the water to reduce noise generated by the pumps citation needed The hot water from the reactor heats a separate water circuit in the steam generator That water is converted to steam and passes through steam driers on its way to the steam turbine Spent steam at low pressure runs through a condenser cooled by seawater and returns to liquid form The water is pumped back to the steam generator and continues the cycle Any water lost in the process can be made up by desalinated sea water added to the steam generator feed water 3 In the turbine the steam expands and reduces its pressure as it imparts energy to the rotating blades of the turbine There may be many stages of rotating blades and fixed guide vanes The output shaft of the turbine may be connected to a gearbox to reduce rotation speed then a shaft connects to the vessel s propellers In another form of drive system the turbine turns an electrical generator and the electric power produced is fed to one or more drive motors for the vessel s propellers The Russian U S and British navies rely on direct steam turbine propulsion while French and Chinese ships use the turbine to generate electricity for propulsion turbo electric transmission citation needed Some nuclear submarines have a single reactor but Russian submarines have two and so had USS Triton Most American aircraft carriers are powered by two reactors but USS Enterprise had eight The majority of marine reactors are of the pressurized water type although the U S and Soviet navies have designed warships powered with liquid metal cooled reactors citation needed Differences from land power plants edit Marine type reactors differ from land based commercial electric power reactors in several respects citation needed While land based reactors in nuclear power plants produce up to around 1600 megawatts of net electrical power the nameplate capacity of the EPR a typical marine propulsion reactor produces no more than a few hundred megawatts Some small modular reactors SMR are similar to marine propulsion reactors in capacity and some design considerations and thus nuclear marine propulsion whether civilian or military is sometimes proposed as an additional market niche for SMRs Unlike for land based applications where hundreds of hectares can be occupied by installations like Bruce Nuclear Generating Station at sea tight space limits dictate that a marine reactor must be physically small so it must generate higher power per unit of space This means its components are subject to greater stresses than those of a land based reactor Its mechanical systems must operate flawlessly under the adverse conditions encountered at sea including vibration and the pitching and rolling of a ship operating in rough seas Reactor shutdown mechanisms cannot rely on gravity to drop control rods into place as in a land based reactor that always remains upright Salt water corrosion is an additional problem that complicates maintenance citation needed nbsp A nuclear fuel element for the cargo ship NS Savannah The element contains four bundles of 41 fuel rods The uranium oxide is enriched to 4 2 and 4 6 percent U 235As the core of a seagoing reactor is much smaller than a power reactor the probability of a neutron intersecting with a fissionable nucleus before it escapes into the shielding is much lower As such the fuel is typically more highly enriched i e contains a higher concentration of 235U vs 238U than that used in a land based nuclear power plant which increases the probability of fission to the level where a sustained reaction can occur Some marine reactors run on relatively low enriched uranium which requires more frequent refueling Others run on highly enriched uranium varying from 20 235U to the over 96 235U found in U S submarines 4 in which the resulting smaller core is quieter in operation a big advantage to a submarine 5 Using more highly enriched fuel also increases the reactor s power density and extends the usable life of the nuclear fuel load but is more expensive and a greater risk to nuclear proliferation than less highly enriched fuel 6 A marine nuclear propulsion plant must be designed to be highly reliable and self sufficient requiring minimal maintenance and repairs which might have to be undertaken many thousands of miles from its home port One of the technical difficulties in designing fuel elements for a seagoing nuclear reactor is the creation of fuel elements that will withstand a large amount of radiation damage Fuel elements may crack over time and gas bubbles may form The fuel used in marine reactors is a metal zirconium alloy rather than the ceramic UO2 uranium dioxide often used in land based reactors Marine reactors are designed for long core life enabled by the relatively high enrichment of the uranium and by incorporating a burnable poison in the fuel elements which is slowly depleted as the fuel elements age and become less reactive The gradual dissipation of the nuclear poison increases the reactivity of the core to compensate for the lessening reactivity of the aging fuel elements thereby extending the usable life of the fuel The compact reactor pressure vessel is provided with an internal neutron shield which reduces the damage to the steel from constant neutron bombardment citation needed Decommissioning editDecommissioning nuclear powered submarines has become a major task for U S and Russian navies After defuelling U S practice is to cut the reactor section from the vessel for disposal in shallow land burial as low level waste see the ship submarine recycling program In Russia whole vessels or sealed reactor sections typically remain stored afloat although a new facility near Sayda Bay is to provide storage in a concrete floored facility on land for some submarines in the far north citation needed Future designs editRussia built a floating nuclear power plant for its far eastern territories The design has two 35 MWe units based on the KLT 40 reactor used in icebreakers with refueling every four years Some Russian naval vessels have been used to supply electricity for domestic and industrial use in remote far eastern and Siberian towns citation needed In 2010 Lloyd s Register was investigating the possibility of civilian nuclear marine propulsion and rewriting draft rules see text under Merchant Ships 7 8 9 Civil liability editInsurance of nuclear vessels is not like the insurance of conventional ships The consequences of an accident could span national boundaries and the magnitude of possible damage is beyond the capacity of private insurers 10 A special international agreement the Brussels Convention on the Liability of Operators of Nuclear Ships developed in 1962 would have made signatory national governments liable for accidents caused by nuclear vessels under their flag 11 but was never ratified owing to disagreement on the inclusion of warships under the convention 12 Nuclear reactors under United States jurisdiction are insured by the provisions of the Price Anderson Act citation needed Military nuclear ships edit nbsp In addition to nuclear powered aircraft carriers the United States once operated nuclear powered cruisers By 1990 there were more nuclear reactors powering ships mostly military than there were generating electric power in commercial power plants worldwide 13 Under the direction of U S Navy Captain later Admiral Hyman G Rickover 14 the design development and production of nuclear marine propulsion plants started in the United States in the 1940s The first prototype naval reactor was constructed and tested at the Naval Reactor Facility at the National Reactor Testing Station in Idaho now called the Idaho National Laboratory in 1953 Submarines edit Further information Nuclear submarine nbsp The nuclear propelled French submarine Saphir returning to Toulon its home port after Mission HeraclesThe first nuclear submarine USS Nautilus SSN 571 put to sea in 1955 SS was a traditional hull classification symbol for U S submarines while SSN denoted the first nuclear submarine 15 The Soviet Union also developed nuclear submarines The first types developed were the Project 627 NATO designated November class with two water cooled reactors the first of which K 3 Leninsky Komsomol was underway under nuclear power in 1958 16 Nuclear power revolutionized the submarine finally making it a true underwater vessel rather than a submersible craft which could only stay underwater for limited periods It gave the submarine the ability to operate submerged at high speeds comparable to those of surface vessels for unlimited periods dependent only on the endurance of its crew To demonstrate this USS Triton was the first vessel to execute a submerged circumnavigation of the Earth Operation Sandblast doing so in 1960 17 Nautilus with a pressurized water reactor PWR led to the parallel development of other submarines like a unique liquid metal cooled sodium reactor in USS Seawolf or two reactors in Triton and then the Skate class submarines powered by single reactors and a cruiser USS Long Beach in 1961 powered by two reactors citation needed By 1962 the United States Navy had 26 operational nuclear submarines and another 30 under construction Nuclear power had revolutionized the Navy The United States shared its technology with the United Kingdom while French Soviet Indian and Chinese development proceeded separately citation needed After the Skate class vessels U S submarines were powered by a series of standardized single reactor designs built by Westinghouse and General Electric Rolls Royce plc built similar units for Royal Navy submarines eventually developing a modified version of their own the PWR2 citation needed The largest nuclear submarines ever built are the 26 500 tonne Russian Typhoon class The smallest nuclear warships to date are the 2 700 tonne French Rubis class attack submarines The U S Navy operated an unarmed nuclear submarine the NR 1 Deep Submergence Craft between 1969 and 2008 which was not a combat vessel but was the smallest nuclear powered submarine at 400 tons citation needed Aircraft carriers edit The United States and France have built nuclear aircraft carriers French Navy edit nbsp The aircraft carrier Charles de Gaulle of the French NavyThe sole French nuclear aircraft carrier example is Charles de Gaulle commissioned in 2001 a successor is planned 18 The French carrier is equipped with catapults and arresters The Charles de Gaulle has 42 000 tonnes is the flagship of the French Navy Marine Nationale The ship carries a complement of Dassault Rafale M and E 2C Hawkeye aircraft EC725 Caracal and AS532 Cougar helicopters for combat search and rescue as well as modern electronics and Aster missiles 19 United States Navy edit The United States Navy operates 11 carriers all nuclear powered 20 USS Enterprise in service 1962 2012 powered by eight reactor units is still the only aircraft carrier to house more than two nuclear reactors with each A2W reactor taking the place of one of the conventional boilers in earlier constructions 21 Nimitz class ten 101 000 ton 1 092 ft long fleet carriers the first of which was commissioned in 1975 A Nimitz class carrier is powered by two nuclear reactors providing steam to four steam turbines Gerald R Ford class one 110 000 ton 1 106 ft long fleet carrier The lead of the class Gerald R Ford came into service in 2017 with another nine planned Destroyers and cruisers edit Russian Navy edit nbsp The Russian flagship Pyotr VelikySee also Kirov class battlecruiser The Kirov class Soviet designation Project 1144 Orlan sea eagle is a class of nuclear powered guided missile cruisers of the Soviet Navy and Russian Navy the largest and heaviest surface combatant warships i e not an aircraft carrier or amphibious assault ship in operation in the world Among modern warships they are second in size only to large aircraft carriers and of similar size to a World War II era battleships The Soviet classification of the ship type is heavy nuclear powered guided missile cruiser Russian tyazhyolyj atomnyj raketnyj krejser The ships are often referred to as battlecruisers by Western defence commentators due to their size and general appearance 22 United States Navy edit See also Nuclear powered cruisers of the United States Navy The United States Navy at one time had nuclear powered cruisers as part of its fleet The first such ship was USS Long Beach CGN 9 Commissioned in 1961 she was the world s first nuclear powered surface combatant 23 She was followed a year later by USS Bainbridge DLGN 25 While Long Beach was designed and built as a cruiser 24 Bainbridge began life as a frigate though at that time the Navy was using the hull code DLGN for destroyer leader guided missile nuclear 25 The last nuclear powered cruisers the Americans would produce would be the four ship Virginia class USS Virginia CGN 38 was commissioned in 1976 followed by USS Texas CGN 39 in 1977 USS Mississippi CGN 40 in 1978 and finally USS Arkansas CGN 41 in 1980 Ultimately all these ships proved to be too costly to maintain 26 and they were all retired between 1993 and 1999 citation needed Other military ships edit Communication and command ships edit nbsp Command and communications ship SSV 33 UralSee also Soviet communications ship SSV 33 SSV 33 Ural SSV 33 Ural NATO reporting name Kapusta Russian for cabbage was a command and control naval ship operated by the Soviet Navy SSV 33 s hull was derived from that of the nuclear powered Kirov class battlecruisers with nuclear marine propulsion 27 SSV 33 served in electronic intelligence missile tracking space tracking and communications relay roles Due to high operating costs SSV 33 was laid up 27 SSV 33 carried only light defensive weapons These were two AK 176 76 mm guns four AK 630 30 mm guns and four quadruple Igla missile mounts citation needed Nuclear powered UUV edit See also Status 6 Oceanic Multipurpose System The Poseidon Russian Posejdon Poseidon NATO reporting name Kanyon previously known by Russian codename Status 6 Russian Status 6 is a nuclear powered and nuclear armed unmanned underwater vehicle under development by Rubin Design Bureau capable of delivering both conventional and nuclear payloads According to Russian state TV it is able to deliver a thermonuclear cobalt bomb of up to 200 megatonnes four times as powerful as the most powerful device ever detonated the Tsar Bomba and twice its maximum theoretical yield against an enemy s naval ports and coastal cities 28 Civilian nuclear ships edit nbsp Engineer epaulette from SavannahThe following are ships that are or were in commercial or civilian use and have nuclear marine propulsion Merchant ships edit Nuclear powered civil merchant ships have not developed beyond a few experimental ships The U S built NS Savannah completed in 1962 was primarily a demonstration of civil nuclear power and was too small and expensive to operate economically as a merchant ship The design was too much of a compromise being neither an efficient freighter nor a viable passenger liner The German built Otto Hahn completed in 1968 a cargo ship and research facility sailed some 650 000 nautical miles 1 200 000 km on 126 voyages over 10 years without any technical problems citation needed It proved too expensive to operate and was converted to diesel The Japanese Mutsu completed in 1972 was dogged by technical and political problems Its reactor had significant radiation leakage and fishermen protested against the vessel s operation All of these three ships used low enriched uranium Sevmorput a Soviet and later Russian LASH carrier with icebreaking capability has operated successfully on the Northern Sea Route since it was commissioned in 1988 As of 2021 update it is the only nuclear powered merchant ship in service citation needed Civilian nuclear ships suffer from the costs of specialized infrastructure The Savannah was expensive to operate since it was the only vessel using its specialized nuclear shore staff and servicing facility A larger fleet could share fixed costs among more operating vessels reducing operating costs Despite this there is still interest in nuclear propulsion In November 2010 British Maritime Technology and Lloyd s Register embarked upon a two year study with U S based Hyperion Power Generation now Gen4 Energy and the Greek ship operator Enterprises Shipping and Trading SA to investigate the practical maritime applications for small modular reactors The research intended to produce a concept tanker ship design based on a 70 MWt reactor such as Hyperion s In response to its members interest in nuclear propulsion Lloyd s Register has also re written its rules for nuclear ships which concern the integration of a reactor certified by a land based regulator with the rest of the ship The overall rationale of the rule making process assumes that in contrast to the current marine industry practice where the designer builder typically demonstrates compliance with regulatory requirements in the future the nuclear regulators will wish to ensure that it is the operator of the nuclear plant that demonstrates safety in operation in addition to the safety through design and construction Nuclear ships are currently the responsibility of their own countries but none are involved in international trade As a result of this work in 2014 two papers on commercial nuclear marine propulsion were published by Lloyd s Register and the other members of this consortium 8 9 These publications review past and recent work in the area of marine nuclear propulsion and describe a preliminary concept design study for a 155 000 DWT Suezmax tanker that is based on a conventional hull form with alternative arrangements for accommodating a 70 MWt nuclear propulsion plant delivering up to 23 5 MW shaft power at maximum continuous rating average 9 75 MW The Gen4Energy power module is considered This is a small fast neutron reactor using lead bismuth eutectic cooling and able to operate for ten full power years before refueling and in service last for a 25 year operational life of the vessel They conclude that the concept is feasible but further maturity of nuclear technology and the development and harmonisation of the regulatory framework would be necessary before the concept would be viable citation needed Nuclear propulsion has been proposed again on the wave of decarbonization of marine shipping which accounts for 3 4 of global greenhouse gas emissions 29 Merchant cargo ships edit USNS American Explorer United States tanker converted to conventional power while under construction Mutsu Japan 1970 1992 never carried commercial cargo rebuilt as diesel engine powered RV Mirai in 1996 Otto Hahn Germany 1968 1979 re powered with diesel engine in 1979 NS Savannah United States 1962 1972 Sevmorput Russia 1988 present ice strengthened nuclear powered lighter aboard ship LASH carrierIn December 5 2023 the Jiangnan Shipyard under the China State Shipbuilding Corporation officially released a design of a 24000 TEU class container ship known as the KUN 24AP at Marintec China 2023 a premier maritime industry exhibition held in Shanghai The container ship is reported to be powered by a thorium based molten salt reactor making it a first thorium powered container ship and if completed the largest nuclear powered container ship in the world 30 Icebreakers edit Main article Nuclear powered icebreaker Nuclear propulsion has proven both technically and economically feasible for nuclear powered icebreakers in the Soviet and later Russian Arctic Nuclear fuelled ships operate for years without refueling and the vessels have powerful engines well suited to the task of icebreaking citation needed The Soviet icebreaker Lenin was the world s first nuclear powered surface vessel in 1959 and remained in service for 30 years new reactors were fitted in 1970 It led to a series of larger icebreakers the 23 500 ton Arktika class of six vessels launched beginning in 1975 These vessels have two reactors and are used in deep Arctic waters NS Arktika was the first surface vessel to reach the North Pole citation needed For use in shallow waters such as estuaries and rivers shallow draft Taymyr class icebreakers were built in Finland and then fitted with their single reactor nuclear propulsion system in Russia They were built to conform to international safety standards for nuclear vessels 31 All nuclear powered icebreakers have been commissioned by the Soviet Union or Russia citation needed Lenin 1959 1989 museum ship Arktika 1975 2008 decommissioned Sibir 1977 1992 scrapped Rossiya 1985 2013 decommissioned Taymyr 1989 present Sovetskiy Soyuz 1989 2014 decommissioned Vaygach 1990 present Yamal 1992 present 50 Let Pobedy formerly Ural 2007 present Arktika 2020 present 32 Sibir 2021 present Ural 2022 present 33 See also editAir independent propulsion Aircraft Nuclear Propulsion Knolls Atomic Power Laboratory List of United States Naval reactors Naval Reactors Nuclear navy Nuclear powered aircraft Nuclear Power School Soviet naval reactors United States naval reactors United States Navy Nuclear PropulsionReferences edit Wirt John G 1979 A Federal Demonstration Project N S Savannah Innovation in the maritime industry Vol 1 National Academies for Maritime Transportation Research Board National Research Council U S pp 29 36 a b c Trakimavicius Lukas The Future Role of Nuclear Propulsion in the Military PDF NATO Energy Security Centre of Excellence Retrieved 2021 10 15 Viren Chopra Rob Houston ed DK Eyewitness Books Transportation Penguin 2012 ISBN 1465408894 page 60 Moltz James Clay March 2006 Global Submarine Proliferation Emerging Trends and Problems NTI Archived from the original on 2007 02 09 Retrieved 2007 03 07 Acton James December 13 2007 Silence is highly enriched uranium Retrieved 2007 12 13 Ending the Production of Highly Enriched Uranium for Naval Reactors PDF James Martin Center for Nonproliferation Studies Retrieved September 25 2008 Full steam ahead for nuclear shipping World Nuclear News 18 November 2010 retrieved 27 November 2010 a b Hirdaris Spyros Cheng YF Shallcross P Bonafoux J Carlson D Prince B Sarris GA 15 March 2014 Considerations on the potential use of Nuclear Small Modular Reactor SMR technology for merchant marine propulsion Ocean Engineering 79 101 130 doi 10 1016 j oceaneng 2013 10 015 a b Hirdaris Spyros Cheng YF Shallcross P Bonafoux J Carlson D Prince B Sarris GA March 2014 Concept Design for a Suezmax Tanker Powered by a 70 MW Small Modular Reactor Transactions of the Royal Institution of Naval Architects Part A International Journal of Maritime Engineering 156 A1 A37 A60 doi 10 3940 rina ijme 2014 a1 276 Liability for Nuclear Damage World Nuclear Association Retrieved March 17 2011 Brussels Convention on the Liability of Operators of Nuclear Ships International Law Public International Law Retrieved March 17 2011 PDF International Atomic Energy Association Archived from the original PDF on December 17 2010 Retrieved March 17 2011 Nuclear Weapons at Sea Bulletin of the Atomic Scientists 48 49 September 1990 Groves Leslie R Teller Edward 1983 Now it can be told p 388 ISBN 978 0 306 80189 1 Stacy Susan 2000 Proving the Principle A History of the Idaho National Engineering and Environmental Laboratory 1949 1999 ISBN 978 0 16 059185 3 Trakimavicius Lukas Is Small Really Beautiful The Future Role of Small Modular Nuclear Reactors SMRs In The Military PDF NATO Energy Security Centre of Excellence Retrieved 2020 12 05 First submarine circumnavigation Guinness World Records Retrieved 2020 06 02 Le programme du porte avions qui remplacera le Charles de Gaulle est lance 23 October 2018 Pike John Charles de Gaulle Global security Archived from the original on 10 November 2015 Retrieved 15 November 2015 Naval Vessel Register Retrieved 2020 06 01 Speed Thrills III Max speed of nuclear powered aircraft carriers Navweaps com 29 April 1999 Retrieved 20 April 2013 Armi da guerra De Agostini Novara 1985 USS Long Beach CGN 9 John Pike CGN 9 Long Beach John Pike CGN 25 Bainbridge class Global security Nuclear power for surface combatants Defense media network a b Pike J SSV 33 Project 1941 GlobalSecurity org Retrieved 30 October 2015 Russian media nuclear torpedo can destroy the US Europe the world Business Insider Shipping industry should consider nuclear option for decarbonizing experts S amp P Global Platts www spglobal com 2020 11 04 Retrieved 2020 11 06 Chen Stephen 2023 12 05 Chinese shipyard unveils plans for world s first nuclear container powered by cutting edge molten salt reactor South China Morning Post Retrieved 2023 12 07 Cleveland Cutler J ed 2004 Encyclopedia of Energy Vol 1 6 Elsevier pp 336 340 ISBN 978 0 12 176480 7 Na ledokole Arktika podnyat rossijskij flag sudostroenie info in Russian 2020 10 21 Retrieved 2021 02 07 Nuclear powered icebreaker Ural of Project 22220 leaves Murmansk for the first operational voyage PortNews 2 December 2022 Retrieved 4 December 2022 AFP 11 November 1998 in Nuclear Submarines Provide Electricity for Siberian Town FBIS SOV 98 315 11 November 1998 ITAR TASS 11 November 1998 in Russian Nuclear Subs Supply Electricity to Town in Far East FBIS SOV 98 316 12 November 1998 Harold Wilson s plan BBC News storyExternal links editThe World Nuclear Association Naval Nuclear Power Training Command Retrieved from https en wikipedia org w index php title Nuclear marine propulsion amp oldid 1203045309, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.