Patent ID: 7548602
Filing Date: 2009-06-16
Classification: G21C,Y02E

Abstract:
1. A spacer grid for a nuclear fuel assembly including a plurality of elongated fuel rods and a coolant flowing over the fuel rods, the spacer grid comprising: a plurality of interlocking grid straps forming a plurality of four-walled cells structured to support the fuel rods therein, the four-walled cells each including four cell walls having a longitudinal axis; and a plurality of mixing vanes extending from each of the grid straps, each of the mixing vanes including a middle ligament directly extending from a top portion of a corresponding one of the grid straps, an upper piece extending from an upper portion of the middle ligament, and a lower piece extending from a lower portion of the middle ligament, wherein each of the upper piece and the lower piece has at least one of a predetermined bend angle and a predetermined degree of twist, and the middle ligament has at least one of a predetermined rotation angle and a predetermined degree of twist, in order to provide a predetermined affect on the coolant as it flows over the fuel rods and through the fuel assembly.