Coolant mixing grid for nuclear fuel assembly

Abstract

A fuel assembly for a nuclear reactor is described, the fuel assembly including: a plurality of fuel pins (,) extending substantially parallel to the axis of the assembly and to each other; at least two structural grids spaced apart from each other, the grids being in contact with said fuel pins (,) and maintaining said fuel pins substantially mutually parallel and preventing contact therebetween, wherein the fuel assembly further comprises at least one mixing grid (,) situated intermediate said at least two structural grids, the fuel assembly being characterized in that said mixing grid (,) is positioned and fixedly located out of substantial contact with said fuel pins (,), the mixing grid also having turbulence inducing means (,) to promote turbulence in a coolant (,) flowing through said fuel assembly in use and in that the mixing grid is formed from sheet metal wherein the plane of the metal sheet from which the mixing grid is formed lies in a plane which is transverse to the axis of the fuel pin assembly.