Coupling of density wave oscillations in parallel channels with high ordermodal kinetics: application to BWR out of phase oscillations

In this paper, we study the behavior of a system formed by two parallel cha nnels coupled to a multimodal kinetics. The first problem that arises is th e calculation of the reactivity coefficients for the higher modes. This pro blem is solved by means of the introduction of distribution factors for a g iven reactor region which depend on the involved modes. We have also perfor med a detailed analysis of the different instability types which can be obt ained from the model changing the boundary conditions and the feedback gain s of the fundamental and first harmonic modes. (C) 2000 Elsevier Science Lt d. All rights reserved.