Nuclear fuel assembly with holding structure and hold down device

摘要

A nuclear fuel assembly comprises a bundle of elongated fuel rods distributed at nodes of a regular lattice and a structure for retaining said fuel rods. The structure has a lower end piece, and upper end pieces, tie rods connecting said end pieces and grids distributed along the tie rods for maintaining the fuel rods at the nodes. The structure consists of two substructures slidable with respect to each other in the direction of the fuel rods. Springs located between the two substructures spread apart the two end pieces for respective abutment against a lower core plate and an upper core plate.