Three-Dimensional Neutron-Physical Methodology for Calculating a Nuclear-Reactor Cell with Axial Symmetry and Finite Step Along the Axis

Abstract

A methodology for performing three-dimensional calculations of a cell in a nuclear reactor with axial symmetry and a fi nite step along the axis is presented. It is based on a method developed for reactors with a close VVER-type lattice for solving the three-dimensional neutron-transport equation in a cell by separation of variables. A method of calculating the trial functions used at the level of three-dimensional calculations of reactors with axial symmetry by the method of surface quantities is proposed. The results show that if a zone with a large step along the axis is to be calculated, then the corrections associated with the curvature of the neutron fl ux are signifi cant and must be taken into account at the level of core calculations.