2-REGION KINETIC-MODEL FOR REFLECTED REACTORS

Deflected reactors constitute one of the most important classes of nuc lear reactors. Yet, experimental data clearly shows that the kinetic b ehavior of some types of reflected systems cannot be adequately charac terized using the standard point kinetic model. In this work, a two-re gion, nodal kinetic model for reflected systems is developed that appe ars to explain the anomalous behavior of these systems in terms of int egral parameters that are both measurable and calculable. The model is based on previous work by Avery and Cohn. We augment the Avery-Cohn m odel with the introduction of simple probability relationships essenti al to calculating the coupling parameters between the core and the ref lector. Using these probability relationships, we then derive the defi nition of the effective multiplication factor k(eff), in terms of the multiplication factor of the core region, k(e), and the reflector retu rn fraction, f. We also derive the reflected-core inhour equation and introduce expressions to calculate the neutron lifetimes characterizin g the system's static and dynamic behavior. The model is then tested u sing Rossi-alpha data from the University of New Mexico's AGN-201 reac tor. Copyright (C) 1996 Elsevier Science Ltd.