Abstract: Steam generators are in the form of tubular heat exchangers in which molten lead coolant flows within the pipes, while the water-steam flows in a space between the pipes, the steam generators are arranged in separate boxes and communicate with the reactor cavity by means of circulation conduits for raising and discharging the lead coolant, the steam generators and most of the circulation conduits and are arranged higher than the level of the lead coolant within the reactor cavity, and the circulation pumps are arranged within the reactor cavity on the circulation conduits and for raising the “hot” lead coolant, and a technical means is provided for ensuring natural circulation of the lead coolant through the reactor core when the circulation pumps are switched off. The specific volume of lead coolant per unit of power of the reactor is reduced and the safety of the reactor is increased.

Abstract: An active zone includes a homogeneous uranium-plutonium nitride fuel, the mass fraction of which is a minimum 0.305, and consists of central, intermediate and peripheral parts which form fuel assemblies comprising fuel elements with geometrically identical shells but differing heights. The radial distribution of the fuel across the volume of the active zone has a stepped shape. The radius of the central part is from 0.4 to 0.5 of the effective active zone radius, while the height of the fuel column in the fuel elements in the central part is from 0.5 to 0.8 of the height of the fuel column in the peripheral part. The heights of the fuel columns forming a stepped intermediate part for diameters ranging from 0.5 to 0.85 of the effective active zone diameter are within the range from 0.55 to 0.9 of the height of the fuel column in the peripheral part.

Abstract: An active zone includes a homogeneous uranium-plutonium nitride fuel, the mass fraction of which is a minimum 0.305, and consists of central, intermediate and peripheral parts which form fuel assemblies comprising fuel elements with geometrically identical shells but differing heights. The radial distribution of the fuel across the volume of the active zone has a stepped shape. The radius of the central part is from 0.4 to 0.5 of the effective active zone radius, while the height of the fuel column in the fuel elements in the central part is from 0.5 to 0.8 of the height of the fuel column in the peripheral part. The heights of the fuel columns forming a stepped intermediate part for diameters ranging from 0.5 to 0.85 of the effective active zone diameter are within the range from 0.55 to 0.9 of the height of the fuel column in the peripheral part.

Abstract: Steam generators are in the form of tubular heat exchangers in which molten lead coolant flows within the pipes, while the water-steam flows in a space between the pipes, the steam generators are arranged in separate boxes and communicate with the reactor cavity by means of circulation conduits for raising and discharging the lead coolant, the steam generators and most of the circulation conduits and are arranged higher than the level of the lead coolant within the reactor cavity, and the circulation pumps are arranged within the reactor cavity on the circulation conduits and for raising the “hot” lead coolant, and a technical means is provided for ensuring natural circulation of the lead coolant through the reactor core when the circulation pumps are switched off. The specific volume of lead coolant per unit of power of the reactor is reduced and the safety of the reactor is increased.