Major stage completed in assembly of RITM-200 reactor vessel for icebreaker Chukotka


A major stage in the construction of the nuclear icebreaker Chukotka has been completed with the automatic welding of the two halves of the reactor vessel of the ship’s first RITM-200 reactor, according to a statement last week by the Russian state atomic energy corporation Rosatom.  

The work of welding the closure seam that connects the two halves of the RITM reactor vessel was performed by ZIO-Podolsk, a subsidiary of Atomenergomash which is the machine-building division of Rosatom. 

Chukotka is the fifth in a series of nuclear-powered icebreakers that includes the already commissioned Arktika and Sibir, while Ural as well as Yakutia are currently under construction. These ships are part of Rosatom’s Project 22220 designed to construct nuclear-powered icebreakers to help keep the Northern Sea Route in the Arctic open for year-round shipping.  

“Automatic welding of the closure seam was carried out with continuous metal heating to 200 degrees for 7 days. The quantity of deposited metal wire was almost 600 kg, and the seam thickness was 150 mm”, the statement said.  

“The length of the reactor plant vessel for connection of two components – flange with shell ring and the shell ring with the bottom head – was 8 meters”, it added.  

Rosatom also said that manufacture of the second RITM-200 reactor vessel for the Chukotka is in progress, simultaneously. 

Besides, work is also ongoing for the “mechanical processing of the first RITM-400 reactor plant parts for the advanced first-in-class nuclear ice-breaker Russia within the framework of the 10510 Leader project.” The 10510 Leader project is a planned series of Russian nuclear-powered icebreakers, which, when built during this decade, would supersede the Project 22220 icebreakers as the largest and most powerful icebreakers in the world. 

The RITM-200 is an integrated generation III+ pressurised water reactor (PWR) designed to produce 55 MW electricity. The small modular reactor (SMR) project based on RITM-200 reactors features compact design, modularity, short construction period and high safety standards with the service life exceeding 60 years.   

The RITM series SMRs incorporate all the best features of the time-tested PWR technology. It measures 45 percent less in dimension and 35 percent less in mass compared to the KLT-40S reactor that powers the floating nuclear power plant (FNPP) Akademik Lomonosov. The RITM-200 has a compact integrated layout placing equipment within the steam generator casing, halving system weight compared to earlier designs and an improved ability to operate in rolling seas. 

Rosatom’s flagship nuclear icebreaker Arktika, equipped with an RITM 200 reactor and integrated steam generator, has proved to be highly efficient. It successfully navigated the shallow waters en route to the Arctica Gate oil terminal in May 2021, proving its suitability for both open sea, as well as polar river estuary operations.