Nuclear icebreakers

A nuclear-powered icebreaker is a nuclear-powered ship purpose-built for use in waters covered with ice. The only country constructing nuclear-powered icebreakers is Russia. Nuclear-powered icebreakers have been constructed by the USSR and later Russia primarily to aid shipping along the Northern Sea Route in the frozen Arctic waterways north of Siberia. Nuclear-powered icebreakers are much more powerful than their diesel-powered counterparts, and although nuclear propulsion is expensive to install and maintain, very heavy fuel demands and limitations on range can make diesel vessels less practical and economical overall for these ice-breaking duties.

During the winter, the ice along the Northern Sea Route varies in thickness from 1.2 to 2.0 metres (3.9 to 6.5 feet). The ice in central parts of the Arctic Ocean is on average 2.5 metres (8.2 ft) thick. Nuclear-powered icebreakers can force through this ice at speeds up to 10 knots (19 km/h, 12 mph). In ice-free waters the maximum speed of the nuclear-powered icebreakers is as much as 21 knots (39 km/h, 24 mph).

In August 2012 Russia's state-owned nuclear corporation, Rosatom, signed a contract to begin construction on what will be the world's largest nuclear icebreaker, a "universal" vessel that could navigate both shallower rivers and the freezing depths of the Arctic.

Russian Arktika-class icebreakers are used to force through the ice for the benefit of cargo ships and other vessels along the Northern Sea Route, which comprises the eastern part of the Barents Sea, the Pechora Sea, the Kara Sea, the Laptev Sea, and the Eastern Siberian Sea to the Bering Strait. Other important ports include Dikson, Tiksi, and Pevek. Of six Arktika-class icebreakers built in 1975–2007, four are currently in service.

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