Patent Number: 050948059
Section: abstract

A fuel assembly for a pressurized water reactor includes fuel assembly edges and a fuel assembly interior. A bundle of mutually parallel fuel rods with cladding tubes each contain nuclear fuel. A given number of guide tubes are provided for control rods. A support structure includes an upper end with a fuel assembly head, a lower end with a fuel assembly foot, and a plurality of spacers disposed perpendicular to the fuel rods. The spacers have a uniform grid structure with edge meshes formed therein at the fuel assembly edges and inner meshes formed therein in the fuel assembly interior. Each of the inner meshes are surrounded by four respective immediately adjacent meshes each having the same area and each containing a respective one of the guide or cladding tubes or an instrumentation tube. At least one of the four meshes immediately adjacent each given inner mesh with a guide tube, contains a fuel rod cladding tube with a periphery being closer to the guide tube than the fuel rod cladding tubes in the remainder of the four meshes. The cladding tube of the fuel rod in the at least one mesh immediately adjacent the given inner mesh with a guide tube, may have a larger outside diameter than a fuel rod in an edge mesh and/or it may have a central axis being closer to the guide tube than the center of the at least one mesh.