Compacting the core of a commercial high-power lead-cooled fast reactor

Abstract

Two options for the layout of a fast reactor with lead coolant are being considered. The design of the fuel assemblies and core fuel rods is identical to the BREST-OD-300 reactor. One of the layouts is traditional with a flattened core. The other layout is the most compact. It has an elongated core and is characterized by an optimal ratio of core diameter to height in terms of minimal neutron leakage. The electric capacity of the first of them is about 2.9 GW, the second - 13.3 GW. The second layout is a high-temperature reactor. When operating at rated power, the maximum coolant temperature reaches 1631 K. The use of cermets fuel based on UN-PuN mononitride micrograins and uranium metal nanopowder, coolant based on lead thorium ores and tungsten fuel rod coatings made it possible to ensure the safety of reactors in emergency modes such as "anticipated transients without scram". A distinctive feature of the layouts is to reduce the danger of emergency modes when they are applied simultaneously. In all emergency modes, large reserves are maintained up to the maximum permissible temperatures of fuel, coolant and structural materials.