Some new thoughts on the multipoint method for reactor physics applications

The multipoint approach proves to be an efficient method for the neutron kinetics of nuclear reactors and accelerator-drive systems. In the present work some features of multipoint kinetics are discussed with reference to standard discretization schemes, both in space and in energy. In the second part of the paper a physically-base approach to construct a multipoint model is presented. It is shown how the parameters of the model can be derived through a Monte Carlo simulation evaluating transfer probabilities and characteristic times. Some results are obtained for an idealized fast system to evidence the properties of the multipoint parameters. At last, a standard point kinetic model is reconstructed from the multipoint equations, showing the relationship between the classic integral parameters of a multiplying systems and the multipoint parameters. This allows to consider a multipoint model for inverse applications aiming at the experimental determination of integral parameters. (authors)