SHIELDING SYSTEM FOR WATER-MODERATED REACTOR UNIT CONTAINMENT Russian patent published in 2001 - IPC

FIELD: designing and construction of new water- moderated power reactors. SUBSTANCE: annular water-cooled heat-transfer apparatus is installed on concrete cavity floor. Inner diameter of concrete bracket mounted in cavity is smaller than outer diameter of reactor vessel. Large-cell perforated members are mounted on annular heat-transfer apparatus and fill up free space of concrete cavity room under reactor. Large-cell perforated members are made of oxides whose functions are to reduce density of uranium dioxide and to ensure corium flow-up above steel layer. Coolant channels of device are used for passive water make-up of annular heat-transfer apparatus that serves to cool down corium arriving to concrete cavity room under reactor. Annular heat-transfer apparatus is protected against above- design mechanical loads of destroyed reactor equipment and corium by means of concrete bracket and large-cell perforated members. Safety shields, heat- insulating layers, and large-cell perforated members ensure protection against heat shocks. Double-layer heat-transfer apparatus ensures reliable heat transfer due to low-melting material filling space between its layers which reduces heat flow to water due to enlarging augmented heat-transfer surface. EFFECT: improved safety of reactor unit in case of core destruction and corium escape beyond reactor vessel. 33 cl, 11 dwg