Análise das equações da cinética pontual para reatores com combustível líquido circulante

Abstract

The circulation of a fluid fuel is an innovative concept of a few fourthgeneration nuclear reactors, such as the molten salt reactor, whose main objectives are to increase safety and reduce (or reuse) radioactive waste. The circulation of the fuel introduces hydrodynamic phenomena into the system, thus demanding changes in the physical models of the reactor to consider these phenomena. In this work, the influence of the flow velocity in the system, both in the transient and steady state, is analyzed, as well as the changes that this causes in the point kinetics equations. A semi-analytical solution is obtained for a simple case of the stationary system and is used to study the behavior of neutron flux, precursor concentration and multiplication factor of the system as a function of the flow velocity, and also serving as validation for the numerical method to be used for the general case. The point kinetics equations are derived using a methodology analogous to the one used for the common case of solid fuel, and their solutions are compared with those of spatial kinetics for some types of transient, in order to evaluate the limitations of the proposed model.