PROTECTIVE CEILING OF NUCLEAR REACTOR USING SOLID- METAL COOLANT Russian patent published in 2001 - IPC

FIELD: nuclear engineering. SUBSTANCE: ceiling has stationary part with central bore accommodating large-diameter rotating plug mounted in a spaced relation and provided with small-diameter eccentric rotating plug with bore for reactor internal refueling machine; each rotating plug is formed by cover, bottom, and two coaxial external and internal shells; shell-to-shell space is filled with biologic shielding material. Ceiling is provided with natural cooling system in the form of annular headers arranged under plug covers, headers mounted above plug bottoms, and channels that provide communication between them and are uniformly distributed over perimeter inside plugs. EFFECT: enhanced reliability and extended service life. 4 cl, 6 dwg