Space-Dependent Dynamic Simulation of a Fluidized Bed Nuclear Reactor

Modeling of the space-dependent dynamics of a fluidized bed nuclear reactor has been performed. The model consists of coupled neutronics, heat transfer as well as fluid dynamics/fluidization. The granular kinetic energy theory is also incorporated to model the phenomena of gas-solid interaction. A computational scheme for the neutronics comprises the even-parity finite element method while the two fluid model is used for the fluid dynamics. Simulation to the dynamics of the reactor has been performed for an uranium inventory of 120 kg and a coolant inlet velocity of 120 cm/s. The results shows that the fission rate is highly fluctuated but the gas temperature is modest. This issue is quite encouraging as the power production in the turbogenerator line depends on the evolution of gas temperature. Furthermore, despite a highly fluctuating fission rate, the maximum fuel temperature is below the maximum permissible limit. (author)