Calculation of Coupling Coefficients of Coupled Reactors Theory Using the Generalized Perturbation Theory.

Abstract

Recently, rigorous multi-point equations are derived using the region-wise importance functions to produce fission neutrons. Since the coupling coefficients used in these multi-point equations are calculated with the weight of these importance functions but not the adjoint function used in the conventional perturbation theory, errors due to the change of the flux is introduced in the coupling coefficients for a perturbed system if the unperturbed flux is used. It is shown that using the generalized perturbation theory, the coupling coefficients using the unperturbed flux can be obtained taking into account the first order change of the flux due to the perturbation, and the same accuracy as the conventional perturbation theory in which the adjoint function is used can be obtained in the case of one-point reactor.