COMPARISONS OF THE DIFFERENT APPROXIMATIONS LEADING TO MESH CENTERED FINITE-DIFFERENCES STARTING FROM THE ANALYTIC NODAL METHOD

We review the derivation of the Analytic Nodal Method and apply the di fferent approximations such as zero transverse leakage and the truncat ion of the matrix exponentials to obtain the mesh centered finite diff erence approximation. The effect of each of these approximations are t hen compared to a reference solution obtained with the Analytic Nodal Method and a quadratic transverse leakage term. A model of a CANDU-B r eactor with incore reactivity devices (21 adjuster rods and 14 zone co ntrollers) is used to compare the effect of all these approximation st eps. (C) 1998 Elsevier Science Ltd. All rights reserved.