Patent ID: 8401834
Filing Date: 2013-03-19
Classification: G21C,G21D,Y02E

Abstract:
1. A computer implemented method for modelizing a nuclear reactor core, comprising the steps of: partitioning the core in cubes to constitute nodes of a grid for computer implemented calculation, calculating a neutron flux for the core by using an iterative solving procedure of at least one eigensystem, components of an iterant of the eigensystem corresponding either to a neutron flux, to a neutron outcurrent or to a neutron incurrent, for a respective cube to be calculated, wherein neutrons are sorted in a plurality of neutron energy groups, and wherein the iterative solving procedure includes a substep of conditioning the eigensystem into a restricted eigensystem where said neutron energy groups are merged into a smaller number of coarse neutron energy groups, wherein an iteration of the restricted eigensystem solving procedure is: wherein d (out) designates the components of the iterant corresponding to an individual cube m; u, u′ are Cartesian axis indexes; s, s′ are orientations equal to 1 or r and corresponding respectively to a left or a right surface of the individual cube along the respective Cartesian axes u, u′; G, G′ being neutron energy groups, A and C being mono-energetic factors, and Q designating a spectral factor, NGC being a number of neutron energy groups in the selection of neutron energy groups, and μ is a neutron eigenvalue, in which an isotropic term is independent of an outgoing current direction specified by the Cartesian axis u and orientation s, and a throughflow term being defined within the same neutron energy group G along the same Cartesian axis u.