Composite nozzle design for reactor fuel assembly

Claim 1

A nozzle for use with a nuclear reactor fuel assembly in a nuclear reactor, the fuel assembly having fuel rods held by grids, the grids permitting the possibility of upward movement of the fuel rods from the fuel assembly when the fuel rods are acted on by hydraulic forces in the reactor, the nozzle comprising: the casting of square configuration having walls which form a central opening through which coolant flows in an axial direction; ribs in said casting extending across the central opening, said ribs including arms integrally joined with the casting walls and forming openings for allowing coolant flow through the nozzle; a separable removable plate on said casting of a size which corresponds with the size of the central opening, said plate being of a thickness which permits it to be stamped from sheet material; said plate further having spaced ligaments defining axially extending openings therein designed to a size and configuration for directing coolant flow in predetermined directions through the nozzle, and for causing a pressure drop of predetermined magnitude across the nozzle to help assure flow of coolant in the desired amount through the nozzle, the ligaments having a thickness which permits them to be stamped from sheet material with the ligaments being disposed to overlie the ends of all said fuel rods when the nozzle is attached to the fuel assembly, and thus prevent ejection of the fuel rods by hydraulic forces which act therein during operation in the reactor.