Spectral effects induced by the presence of a reflector for two-energy group two-point kinetic model of reflected reactors

The point kinetic model which describes the time-dependent behavior of multiplying systems for a strongly reflected-reactor kinetic has been developed for two-energy group, two-point reactor model. The solution in this work is based on Laplace transformation and an explicit analytical solution for the investigated two-energy group two-point kinetic model. The results are described in terms of an extended inhour equation, which contains multiple mode decay constants, and neutron source transfer functions for the two-energy group of the core and the reflector. The studied model gives a good description of the so-called criticality condition and the effective multiplication factor in terms of the multiplication factor of the core region and the reflector return fractions. In addition, an analytical solution for neutron population and precursor of the bare core and the reflector at different groups and regions has been studied to verify the importance of thermal neutron energy group in such fast-thermal reactor models.