Passive reactor auxiliary cooling system

This patent describes a liquid-metal fast-breeder nuclear reactor which includes a direct reactor core auxiliary cooling system, the reactor comprising: a reactor core disposed within a cylindrical vertically disposed core barrel, a hot-liquid-metal plenum disposed generally above the core barrel, a cylindrical liquid-metal shield forming the lateral peripheral boundary for the hot-liquid-metal plenum, a plenum divider plate extending laterally from the upper exterior portion of the core barrel to the liquid-metal shield and forming the bottom boundary for the hot-liquid-metal plenum, a baffle member affixed to the exterior of the core barrel and laterally extending therefrom to the liquid-metal shield, a radial-flow plenum formed by the plenum divider plate and the baffle member, and a cooled-liquid-metal plenum positioned beneath and about the core barrel and opening into the bottom of the core barrel. The reactor core consists of centrally disposed fuel-assembly region comprising individual fuel assemblies and a surrounding radial-shield-assembly region comprising individual shield assemblies which have apertures provided in the upper lateral walls thereof to permit the flow of liquid metal therethrough, and the upper portion of the core barrel having lateral apertures provided therethrough to permit the flow of liquid metal between the core barrel and the radial-flow plenum