Computation accuracy and efficiency of a polynomial nodal method for diffusion and spatial burnup problems

The accuracy and computational efficiency of a polynomial nodal method (PNM) in solving multigroup neutron diffusion problems in three space dimensions, particularly the long-term burnup problems in PWRs, with their inevitable power-dependent effects is demonstrated. With this in mind, PNM is accurately assessed against other well-grounded nodal methods such as the analytic nodal method and the nodal expansion method, in the case of a well-known PWR benchmark problem, and appears to be as accurate and efficient, as regards the determination of both node-average values and detailed flux distributions inside homogenized nodes. Moreover, the practical applicability of the method to the analysis of fuel cycles in actual PWRs is documented positively. (author)