The concept of a compact and safe high-power lead-cooled fast reactor.

The layout of a lead-cooled fast reactor with an electrical power of 1.5 GW is considered. The design of the BREST-OD-300 reactor is taken as the basis. It is proposed to use cermets based on micrograins of mononitride and nanopowder of metallic uranium as fuel. Lead extracted from thorium ores is considered as a coolant. Fuel rod coatings (claddings) are hermetically sealed capsules made of tungsten. The compactness of the reactor layout is ensured by approximately the same diameter D (2.816) and height H (2.601) of the core. In this case, the ratio D/H = 1.0826 corresponds to minimal neutron leakage from the reactor, which is not typical for fast reactors with liquid metal coolant. An increase in the height of the core to an anomalous value is possible by excluding the implementation of the positive void reactivity effect, which is provided, for example, in BREST-type reactors. In all possible emergency modes (including ATWS - anticipated transient without scram), large temperature reserves are maintained before the onset of intensive decomposition of mononitride, boiling of lead, melting or depressurization of fuel element cladding. [ABSTRACT FROM AUTHOR]