A Space-Time Reactor Simulation

Abstract

The design of a lattice cell type space-time dynamic calculation is discussed. The thermalhydraulic behavior of the coolant is modeled using the microscopic form of the Navier Stokes equations. The multigroup diffusion approximation is used to model neutron behavior. The overall setup of the problem is discussed including: the allocation of memory, array structures, the effect that this has upon the numerical solution and the numerical methods that could be used. Coupling between the neutronics and the thermalhydraulics occurs at each spatial point within the coolant. The thermal feedback effects include Doppler broadening of the cross sections within the fuel and density changes in the coolant. The rate form of the equation of state is used in the solution of the incompressible flow problem. The derivation of this method is quite straight forward and fits in well with the other rate equations found in the time dependent problem.