Arktika-class icebreaker
The "Arktika" class is a Russian (former Soviet) class of nuclear-powered icebreakers. Formerly known as "Project 10520 nuclear-powered icebreaker", they were the largest and most powerful icebreakers until the 2016 launch of the ship named Arktika. Ships of the "Arktika" class are owned by the federal government, but were operated by the Murmansk Shipping Company (MSCO) until 2008, when they were transferred to the fully government-owned operator Atomflot. Of the ten civilian nuclear-powered vessels built by Russia (and the Soviet Union), six have been of this type. They are used for escorting merchant ships in the Arctic Ocean north of Siberia as well as for scientific and recreational expeditions to the Arctic.
Icebreaker
The steam-powered icebreakers were resurrected in the late 1950s when the Soviet Union commissioned the first nuclear-powered icebreaker, "Lenin", in 1959. It had a nuclear-turbo-electric powertrain in which the nuclear reactor was used to produce steam for turbogenerators, which in turn produced electricity for propulsion motors. Starting from 1975, the Russians commissioned six "Arktika"-class nuclear icebreakers of which the last, 2007-built "50 Let Pobedy", is the largest and most powerful icebreaker in the world at . In addition, two shallow-draft "Taymyr"-class nuclear icebreakers were built in Finland for the Soviet Union in the late 1980s. The Soviets also built a nuclear-powered icebreaking cargo ship, "Sevmorput", which had a single nuclear reactor and a steam turbine directly coupled to the propeller shaft. Russia, which remains the sole operator of nuclear-powered icebreakers, is currently building a new icebreakers to replace the aging "Arktika" class. The first vessel of this type is expected to enter service in 2017.