Nuclear Energy News

Russia’s Chukotka Icebreaker Reaches First Reactor Milestone

Summary not found.

One of the two reactors aboard Russia’s nuclear-powered icebreaker Chukotka has been brought to “minimum controlled power level” for the first time, the vessel’s builder confirmed this week, marking a milestone on the ship’s path toward sea trials and delivery to operator Rosatom. The starboard reactor unit’s start-up was reported by World Nuclear News on October 26, following an earlier account from the Baltic Shipyard that described the same calibration step around October 19.

What the Milestone Means

Bringing a reactor to minimum controlled power is an early step in reactor commissioning: operators withdraw control rods until the reactor sustains a self-sustaining chain reaction at the lowest power level that can be measured and controlled, allowing engineers to confirm that the reactor core, control rods, and protection and monitoring systems are all functioning correctly before power is raised further. The Baltic Shipyard, which is building Chukotka in St. Petersburg, said the calibration followed months of commissioning work, equipment testing, safety-system checks and the loading of nuclear fuel assemblies into the reactor. Full physical start-up of both of the vessel’s reactor units, and a subsequent series of power-plant tests, are still to come before the ship proceeds to factory sea trials.

A Fifth Icebreaker in a Growing Fleet

Chukotka is the fifth vessel in Russia’s Project 22220 class, the world’s largest and most powerful icebreakers, built at the Baltic Shipyard for state nuclear corporation Rosatom. It was laid down in December 2020 and launched in November 2024, and two sister ships, Leningrad and Stalingrad, are under construction behind it. The four Project 22220 vessels already in service — Arktika, Sibir, Ural and Yakutia — have spent recent years escorting cargo convoys along Russia’s Northern Sea Route, the Arctic shipping corridor Moscow is promoting as a faster link between Europe and Asia. Each Project 22220 ship is 173 meters long and can break ice up to 3 meters thick.

The Reactors Powering the Fleet

Chukotka’s two RITM-200 reactors each produce 175 MW of thermal power, giving the vessel a rated service life of 40 years with refueling required only once every seven years — a far longer interval than older Soviet-era icebreaker reactors required. Each reactor unit weighs more than 147 tonnes and is built to keep operating through the rolling and pitching of Arctic seas, rated to withstand a 45-degree roll and 15-degree pitch. The RITM-200’s internals are designed and supplied by Afrikantov OKBM, part of Rosatom’s machine-building division, with the reactor vessels fabricated by ZiO-Podolsk; the companies have now completed 15 RITM-200 units, with 13 more under construction for the icebreaker program and other applications. A larger derivative, the RITM-400, is being built for Rossiya, the lead ship of a new, even larger icebreaker class targeted for service by 2030.

The RITM-200’s compact, long-refueling-interval design has also drawn interest beyond icebreakers — the same reactor family underpins some of Russia’s floating power plant and small modular reactor concepts, the kind of compact naval-derived reactor technology also under development by Western manufacturers such as Rolls-Royce.

Sources

World Nuclear News, “First reactor unit launched on Chukotka icebreaker,” October 26, 2026 — milestone confirmation, reactor and vessel specifications.
Baltic Shipyard (JSC, part of United Shipbuilding Corporation), public statement on Chukotka’s reactor commissioning, reported around October 19, 2026 — commissioning timeline, fuel loading.
World Nuclear News, background reporting on Project 22220 icebreakers and RITM-200/RITM-400 reactor programs.