Fuel element lattice restraint structure - with integral constraints to inhibit swelling of fuel element cladding

摘要

Square lattice fuel element restraint structure, applicable to heterogeneous reactors, in which the vertical corrugated profiled side members of each compartment of the structure constrain fuel element verticality. Inward projecting spurs integral with the side members or alternatively in diagonally opposed locations at the corners of each compartment inhibit swelling of the fuel element cladding in excess of a predetermined distance. A further variant provides for close fitting cylindrical collars around the fuel elements with profiled tabs to maintain positional restraint and radially projecting spurs to inhibit swelling of the cladding of adjacent elements.