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 different approximations such as zero transverse leakage and the truncation of the matrix exponentials to obtain the mesh centered finite difference approximation, The effect of each of these approximations are then compared to a reference solution obtained with the Analytic Nodal Method and a quadratic transverse leakage term. A model of a CANDU-6 reactor with incore reactivity devices (21 adjuster rods and 14 zone controllers) is used to compare the effect of all these approximation steps