Fuel assembly and associated grid for nuclear reactor

摘要

An improved grid 20 for use in a fuel assembly of a nuclear reactor includes a plurality of straps 42, 46, 50, 54 that are interconnected with one another in a lattice fashion to define a plurality of cells 58, with the straps 42, 46, 50, 54 being configured to include a plurality of relatively more compliant springs 98a and a plurality of relatively less compliant dimples 102a, whereby each cell includes only one pair of springs 98a and one pair of dimples 102a disposed therein. The springs and dimples 98a, 102a are contoured to engage a fuel rod or a thimble tube disposed within the cell 58. Each spring 98a directly confronts one of the dimples 102a to provide confronting pairs of features that engage the fuel rods or thimble tubes, with each cell including two pairs of confronting features. The ligaments of the springs 98a and dimples 102a extend in a direction generally perpendicular to the direction of coolant flow through the reactor in order to minimize pressure drop.