Numerical methods used in neutronics calculations

An earlier submission (Pollard 1966 - M.Sc. thesis) considered neutron interactions in a homogeneous space independent reactor system and studied the influence of long time variations (burnup over years) on the interactions. Here we are concerned with neutron interactions in a multiregion reactor, essentially represented by two space dimensions, and we will study the influence of short time variations (kinetics over seconds) on the interactions. The present work concerns numerical solution of the neutron diffusion equation using well proven methods but includes methods for (1) speedy estimation of extrapolation parameters and (2) rebalance to enhance convergence. Under (1) re-estimation of parameters is possible using preoptimum estimates for the parameters and (2) features of the Sokolov method are studied.