Partial Equations of Reactor Kinetics

Ordinarily, a system of two equations is used to analyze the spatial kinetics of a reactor, i.e., to determine the neutron field in each computational cell at any time during a non-stationary process. One equation describes the neutron flux density and the second one describes the precursors of delayed neutrons. In this case, the density includes the flux density of prompt (immediately during fission) of a nucleus as well as the delayed neutrons resulting from the decay of fission fragments. We shall call the indicated system of equations the classical system, since it can be transformed into a single integro-differential equation. In the present work, the possibility of representing the neutron flux density in a non-stationary process by separate equations for prompt and delayed neutrons is examined and the results of modeling of the non-stationary process accompanying the insertion of a CPS rod in a medium power fast reactor are presented. We shall call this system a system of partial equations.