Reactor Plants for Nuclear-Powered Icebreakers and Other Ships

Russia is the only country in the world that has a fleet of nuclear-powered civil ships. The nuclear-powered icebreakers have been successfully operating in the Arctic region for more than half a century, while providing reliable and safe navigation of cargo ships in all the sectors of the North Sea Route.

JSC “Afrikantov OKBM” is a chief designer of all the marine reactor plants for the nuclear icebreaker fleet.

The first Soviet nuclear-powered icebreaker Lenin was commissioned in 1959. It was a world’s first nuclear-powered surface ship, which was unparalleled in power among icebreakers of the entire world. As a source of energy, the OK-150 nuclear steam supply system was adopted. This is a reactor plant that has a distributed layout, i.e. the main equipment of the loop is placed in separate vessels connected via piping. In 1970, the OK-900 nuclear steam supply system was installed on the icebreaker. It was a new generation modular nuclear steam supply system, i.e. the reactor, the pumps and the steam generators had individual vessels and were connected via short coaxial nozzles. Throughout the time in operation, which lasted up to 1989, the nuclear-powered icebreaker Lenin took 3,700 vessels through the ice. The operation of the icebreaker verified the high efficiency of using nuclear energy on the ships of the icebreaking fleet.


The first Soviet nuclear-powered icebreaker Lenin

The successful operation of the first nuclear-powered icebreaker laid a foundation for the development of a new industry, civil nuclear shipbuilding. Throughout the period of 1975–2006, our country constructed 8 more nuclear-powered icebreakers: Arktika, Sibir, Rossiya, Sovetskiy Soyuz, Taymyr, Vaygach, Yamal, 50 Let Pobedy, and the ocean-going ice-reinforced lighter aboard ship Sevmorput.


Nuclear-powered icebreaker Vaygach in the port of Dudinka


Soviet/Russian icebreaking cargo ship (lighter aboard ship) Sevmorput powered by the KLT-40 nuclear propulsion plant. In terms of displacement, it is the largest ship among nuclear-powered non-military cargo ships that have ever been constructed.

According to JSC “Afrikantov OKBM” designs, 20 nuclear reactors have been manufactured and operated on 10 ships.

For these nuclear-powered ships, JSC “Afrikantov OKBM” developed 3 versions of the reactor plants: OK-900A, KLT-40, KLT-40M

NSSS type,
ship’s name

OK-150, Lenin

OK-900, Lenin

OK-900A, Arktika,
Sibir, Rossiya,
Sovetskiy Soyuz,
50 Let Pobedy

KLT-40, Sevmorput

KLT-40M, Taymyr, Vaygach

Reactor thermal power, MW






The entire set of systems and equipment for these plants was created and commissioned with participation of the Company’s specialists. Part of the reactor plant equipment was manufactured in the JSC “Afrikantov OKBM” production facilities. The Company provides field supervision for operation of the propulsion plants on icebreaking ships.

The icebreaker fleet operating practice, which is in use up to this day, implies that open-sea icebreakers escort ship caravans in deep-water sectors. In shallow-water sectors, the icebreakers are used that have a limited draft. In this situation, the caravans have to be transferred from an open-sea icebreaker to a small-draft icebreaker and vice versa. This results in ships’ downtime and has a negative effect on the economic efficiency of shipping.

To optimize the operations of the nuclear icebreaker fleet, a project is underway to construct new-generation double-draft multipurpose nuclear-powered icebreakers, which can combine the functions of the open-sea icebreakers and the limited-draft icebreakers. JSC “Afrikantov OKBM” has developed new-generation RITM-type reactors.

The RITM-200 is the latest reactor plant that JSC “Afrikantov OKBM” has developed for the lead nuclear-powered icebreaker Arktika. The plant incorporates two reactors each having a thermal power of 175 MW.


Transporting the RITM-200 steam generating unit

The nuclear-powered icebreaker is 173 meters long; its beam is 34 meters; the minimum operating draft is 8.5 meters; the displacement is 33,500 tons. It is planned that the icebreaker will be able to escort ship caravans under the Arctic conditions with breaking through the ice up to 3 meters thick on its way.

On June 16, 2016, a formal ceremony was held to launch the hull of the lead nuclear-powered icebreaker Arktika.


  The lead nuclear-powered icebreaker Arktika with the reactor plant RITM-200 officially came into commission on October 21, 2020.

By the present moment, the delivery of RITM-200 reactor plant equipment for three multipurpose nuclear-powered icebreakers Arktika, Sibir and Ural has been completed. In 2020, after completion of sea trials, the lead multipurpose nuclear-powered icebreaker of new generation Arktika was handed over to the customer. The developed reactor plant designs may not only be used for nuclear-powered icebreakers but also for civil vessels and floating and land-based small-sized nuclear power plants of single-unit and modular designs.

By 2027, the nuclear fleet will be reinforced with a series of new-generation nuclear-powered icebreakers incorporating the RITM-200 reactor plants.

The Project 22220 nuclear-powered icebreakers are the largest and most powerful in the world. They will provide navigation of ships with hydrocarbon raw material from the minefields of Yamal, Gydan peninsulas and Kara Sea shelf to the markets of Asian-Pacific countries.

JSC “Afrikantov OKBM” is designing the RITM -400 reactor plant for the Leader-class nuclear powered icebreaker, which will enable year-round navigation along the Northern Sea Route.

The engineering solutions put into the RITM-200 reactor plant design are legally protected, and today JSC “Afrikantov OKBM” has the rights to:
  • 8 inventions,

  • 4 utility models,

  • 21 computer programs,

  • 96 production secrets (know-hows).  

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