1. Context

   The Soviet Union has been developing the use of nuclear energy for power generation since the end of the Second World War. The first prototype in operation was based on graphite concepts, but other designs soon followed, in particular those of the VVER ( Vodo-Vodyanoi Energeticheskiy Reactor  ; water-to-water power reactor), which is broadly similar to the pressurized water power plants (PWR) developed in the West.

   However, the actual designs and construction choices for VVERs and Western PWRs have their own specificities, particularly with regard to buildings, fuel, steam generators and primary pumps. The technical exchanges in the 1990s between the West, the new Russian Federation and the countries of Eastern Europe led to a convergence of design principles. However,...