Patent Number: 
Section: claims

1. A nuclear fuel assembly lower end fitting comprising:a flow channel plate on which a plurality of fuel rods and instrumentation tube are disposed;an assembly groove formed in the flow channel plate, wherein the instrumentation tube is inserted into the assembly groove, wherein an outer surface of the instrumentation tube contacts with a side wall of the assembly groove, wherein the assembly groove includes a center vertical axis;a plurality of first flow holes formed in the flow channel plate around the assembly groove; anda plurality of second flow holes formed in the flow channel plate under the assembly groove, wherein the second flow holes communicate with the assembly groove,whereinall of the second flow holes are spaced the same distance from the vertical axis at regular interval with each other, andnone of the second flow holes extend under the vertical axis, andall of the second flow holes are spaced inward from the side wall of the assembly groove, wherein a lower end of the instrumentation tube does not block the second flow holes even when the lower end of the instrumentation tube contacts a bottom of the assembly groove. 2. The nuclear fuel assembly lower end fitting of claim 1, wherein the second flow holes are arranged symmetrically around the vertical axis.