Spacer grid with side welding support and flow mixing vane for nuclear reactor fuel assembly

Abstract

A spacer grid for nuclear fuel assemblies is disclosed. This spacer grid has a plurality of side weld supports, that is, main supports, upper sub-supports and lower sub-supports, on its interlaced inner straps, with two flow mixing vanes integrally extending upward from each of the main supports. This spacer grid is fabricated by seam-welding the interlaced first and second inner straps to each other along the upper axial junction lines of the crossing main and upper sub-supports at the top of the intersections, and along the lower axial junction lines of the crossing lower sub-supports at the bottom of the intersections, thus forming side weld lines at the intersections. This spacer grid reduces the damage of fuel rod during a fuel rod insertion process by decreasing interference between flow mixing vanes and fuel rods, accomplishes a desired soundness by seam welding, improves the coolant mixing efficiency of the flow mixing vanes by excluding welding windows, and reduces hydraulic resistance caused by weld beads.