Nodal calculation of neutron fields in hexagonal lattices

摘要

A modified polynomial nodal method of calculating the neutron flux-density distribution in nuclear reactors with a hexagonal fuel-assembly configuration is proposed, with solution of the diffusion equation in rectangular geometry. The method is adapted for hexagonal configurations by conformal mapping of the interior of a hexagon onto a rectangle. The accuracy of solution of the diffusion equation in a two-group diffusional approximation in hexagonal arrays is demonstrated for the example of three-dimensional model problems describing VVER-1000 and VVER-440 water-cooled, water-moderated reactors.