Patent ID: 6608881
Filing Date: 2003-08-19
Classification: G21C,Y02E

Abstract:
A duct-type spacer grid for placing and supporting a plurality of elongated fuel rods within a nuclear fuel assembly, comprising:a plurality of duet-shaped grid elements individually having a plurality of elongated sidewalls which form a polygonal cross-section, said grid elements being closely arranged in parallel and assembled together to form a plurality of main flow paths of polygonal cross-section for allowing coolant to pass, each of said grid elements comprising: a plurality of the plurality of sidewalls having spring windows and at least four of the plurality of sidewalls without spring windows; a line contact spring provided on each of said spring windows and being bent toward the center of each grid element at a central portion thereof, for supporting an external surface of a fuel rod in each grid element; and a plurality of integral swirl flow vanes of different heights axially extending from a top surface of each sidewall having spring windows, each of said vanes being bent twice outwardly from each grid element toward the center of an associated flow path for generating a swirl flow of coolant.