Heat protection elements for metal cooled nuclear reactor - made up by superimposed layers of metal mesh on wall of cooling annulus

摘要

A bleed-off of the liq. metal coolant of a nuclear reactor flows up an annular ring section and over a rim before returning to the main body of liq. On the wall just below the edge of the rim are fixed, by gudgeon bolts, heat insulating elements through which the liq. metal flows to retard its velocity. These insulating elements are made up of panels forming superimposed layers of metal mesh or trellis work, the layers having equal or different thicknesses. The edges of the superimposed layers are offset laterally so that the edges are covered, and a constnat height and thickness of insulating elements are obtd. The panel sof the first and last layers are covered by overlapping thin metal sheets to prevent leakage to outside the elements. Layers of the elements are sepd. by thin metal sheets or by a grating thicker than th metal mesh. Over each panel in the last layer ther eis a metal covering plate used to compress the layers by menas of the gudgeon bolt. Used in fast breeder nuclear reactors cooled by a liq. metal, usually sodium. The process reduces the speed of fall of the liq. metal over the rim os that the gas of the inert blanket is not entrained in the liq. bulk.