The 355-tonne component was manufactured at Atomenergomash's Volgodonsk plant and transported via a route including 1500 kilometres by barge and 300 kilometres by road to the Kursk site, which is about 500 kilometres south of Moscow.
Plant owner Rosenergoatom said steam generators for the VVER-TOI units were slightly bigger at 15 metres long and four metres wide than the equivalents for Russia's current mainstay VVER-1200 design.
The 1255 MWe VVER-TOI is a Generation III+ power unit developed using technical results from the VVER-1200 project. The design is said to offer improved safety measures, including an increased margin of safety from extreme impacts and ability to withstand earthquakes, and is equipped with modern control systems and diagnostics.
Two VVER-TOI units are under construction at Kursk-II, with the intention of them being operational in time to replace the four RBMK reactors at Kursk, which begin to retire from 2022. Construction of Kursk-II 1 began in April 2018 and unit 2 a year later.