A SELF-CONSISTENT NODAL METHOD IN RESPONSE MATRIX FORMALISM FOR THE MULTIGROUP DIFFUSION

We develop a nodal method for the multigroup diffusion equations, base d on the transverse integration procedure (TIP). The efficiency of the method rests upon the convergence properties of a high-order multidim ensional nodal expansion and upon numerical implementation aspects. Th e discrete 1D equations are cast in response matrix formalism. The der ivation of the transverse leakage moments is self-consistent i.e. does not require additional assumptions. An outstanding feature of the met hod lies in the linear spatial shape of the local transverse leakage f or the first-order scheme. The method is described in the two-dimensio nal case. The method is validated on some classical benchmark problems .