COATED NUCLEAR-FUEL PELLET (VERSIONS), METHOD AND PLANT FOR PELLET COATING Russian patent published in 1999 - IPC

FIELD: nuclear technology; manufacture of fuel elements for nuclear reactors. SUBSTANCE: pellet covered with multilayer coating on cylindrical surface has underlayer that has additional zirconium oxide film on fuel material surface. Method implies that pellets have axial cylindrical bore or two blind axial holes. For coating, pellets are arranged by means of axial holes into vertical strings or piles which are rotated in vacuum chamber about its axis aligned with axes of pellets placed into it. Plant implementing this method has vacuum chamber holding cathodes plates made of coating material and anodes. Novelty is also that revolving mechanism is mounted for rotation about its vertical axis and each holder is made in the form of hanger for locking and centering single pile of pellets placed vertically in revolving mechanism for rotating about its axis and incorporates mechanism ensuring this rotation. EFFECT: improved uniformity and adhesion of coating with fuel material. 15 cl, 9 dwg, 1 tbl