GRID STRUCTURE OF A HEAT-GENERATING ASSEMBLY OF NUCLEAR REACTOR

摘要

The invention relates to nuclear engineering and is intended to be used in the structures of the spacer and mixing grids of fuel assemblies for nuclear power reactors. The grid structure of a fuel assembly with a triangular arrangement of fuel elements is made up of cells. The cells are in the form of faceted tubes and are adjoined by the tube faces. The longitudinal axes of these faces are parallel to the fuel assembly axis and are situated at the nodes of a triangular grid. The end parts of each cell are polyhedral. The middle part of at least a group of cells is provided with grooves. The faces of one of the end parts of each of these cells arc offset around the longitudinal axis of the cell relative to the analogous faces of the other end part of the same cell. All the faces are parallel to the longitudinal axis of the cell. Three non-adjacent faces are disposed around the axis of each cell at an interval of 120° and are of equal width, the width being greater than that of the other faces, thereby making it possible to form heat carrier channels when the cells are joined. The invention makes it possible to improve operational reliability by increasing the critical heat flux owing to the formation of extended cross flows along the fuel clement rows, which flows cause the efficient mixing of the heat carrier between the cells without removing liquid from the fuel clement surfaces.