Specialists of the Central Engineering Design Bureau (TsKBM – Tsentralnovo Konstruktorskovo Byuro Mashinostroeniya), part of Rosatom’s Engineering Division, completed the acceptance tests for all four main circulation pumps for unit 1 of Russia’s Kursk-II NPP.

The new generation main circulation pumping units (GTsNA – Glavnikh Tsirkulyatsionikh NasosnikhAgregatov) differ from the previous generation in that water, rather than oil, is used to lubricate and cool the pump and electric motor components. Eliminating the oil system makes it possible to increase fire safety at NPPs, and the single-shaft arrangement leads to a reduction in the number of bearings in the unit, which increases its reliability.

They have new design features. In particular, the connection between the shafts of the removable part and the electric motor with a flexible coupling has been replaced with a rigid connection. “This made it possible to abandon the use of separate radial support bearings for the engine and the removable part and move to a design with a single bearing located in the electric motor,” noted Rodion Kazantsev, Chief Designer for Pumping Equipment at TsKBM. “This approach will reduce the repair time of pumping equipment. For example, at TsKBM assembly sites, dismantling and inspection of an electric motor is now carried out in three shifts.”