Lambda modes of the neutron-diffusion equation: Application to B.W.R.'s out-of-phase instabilities

Abstract

This paper deals with the calculation of the harmonic lambda modes and the eigenvalue separation in B.W.R. reactors. Several methods have been developed for the exact and approximate calculation of the lambda modes in 1D, and two energy groups. The paper also includes the calculation of the most important 3D subcritical lambda modes using a consistent synthesis approach. In this way, we have computed the harmonic modes that can be excited during out-of-phase oscillations.