METHOD AND DIE FOR MANUFACTURING THREE-LAYER TUBULAR RIBBED FUEL ELEMENTS Russian patent published in 1997 - IPC

FIELD: nuclear power engineering; manufacture of dispersed-core fuel elements. SUBSTANCE: method involves production of finely dispersed powders for fuel elements manufactured by powder metallurgy process by mixing up powders of source materials in liquid plasticizer environment, cold press-fitting of core into blank using plasticizer contained in powder mixture to function as lubricant. Liquid plasticizer is introduced in charge in the course of mixing process by separate batches in the form of aerosol, and mixing is carried out for time sufficient to ensure uniform distribution of fissionable phase throughout nonfissionable phase. Then hot molding is performed with core finished to desired density and size using for lubrication products of fossil material decomposition by heat. Die implementing this method has conical entry section with shaping ribs and sector flats uniformly distributed over die circumference so that angle smaller than that of entry cone is formed between them and die longitudinal axis; it also has finishing ring with longitudinal slots; sector flats are made so that sides of each of them form angle of at least 180 deg. Sides of adjacent sector flats converge at point on outer diameter of entry cone. EFFECT: facilitated procedure; improved finishing of fuel elements. 4 cl, 8 dwg