Nuclear marine propulsion
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.
[1] Compared to oil- or coal-fuelled ships, nuclear propulsion offers the advantage of very long intervals of operation before refueling.
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.
[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.
[7] 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).
[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).
[15] Under the direction of U.S. Navy Captain (later Admiral) Hyman G. Rickover,[16] the design, development and production of nuclear marine propulsion plants started in the United States in the 1940s.
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.
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.
[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.
The sole French nuclear aircraft carrier example is Charles de Gaulle, commissioned in 2001 (a successor is planned).
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.
The Soviet classification of the ship-type is "heavy nuclear-powered guided missile cruiser" (Russian: тяжёлый атомный ракетный крейсер).
While Long Beach was designed and built as a cruiser,[26] Bainbridge began life as a frigate, though at that time the Navy was using the hull code "DLGN" for "destroyer leader, guided missile, nuclear".
[citation needed] 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.
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 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.
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.
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 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.
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.
[10][11] 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).
[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.
[32] Nuclear propulsion has proven both technically and economically feasible for nuclear-powered icebreakers in the Soviet, and later Russian, Arctic.
[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).
[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.
