The effect of the anisotropic scattering on the thermal utilization factor

In calculations of the thermal utilization factor for heterogeneous reactors the anisotropic scattering is taken into account usually in the transport and sometimes in the linear-anisotropic approximations. The work of Eccleston and McCormick make doubtful the generally accepted opinion that the second angular moment of the scattering kernel has little effect on the disadvantage factor in slab cells in nuclear reactors.

In the present work we have investigated the effect of the second and higher angular moments of the scattering kernel on the thermal utilization factor. The formulas appropriate for the qualitative analysis of the question under consideration are given and a set of cells was calculated by various methods. A disagreement between the data obtained and those reported by Eccleston and McCormick is shown.