LAMBDA MODES OF THE NEUTRON-DIFFUSION EQUATION - APPLICATION TO BWRS OUT-OF-PHASE INSTABILITIES

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