Nuclear fuel assembly with a free end grid

摘要

A nuclear fuel assembly comprising a plurality of fuel elements, a structure having an upper end piece and a lower end piece rigidly connected together by tie rods and a plurality of spacing grids. The plurality of spacing grids comprises two end grids, one being connected to the fuel elements and secured to the tie rods and the other being connected to the fuel elements and slidably received by the tie-rods, and a plurality of intermediate grids secured to the tie-rods and slidably received by the fuel elements. The bundle of fuel elements can extend and retract from the end grid which is secured to the tie rods while being maintained and supported by the structure.