The analytical solution to the linear nonautonomous system of point reactor kinetics equations

The paper presents the analytical solution to the linear nonautonomous system of point reactor kinetics equations with one group of delayed neutrons and the reactivity described by any smooth function of time. To obtain the solution, an asymptotic series in a small parameter is constructed. Numerical results to show a fast convergence of the series are discussed. The case of the reactivity linearly dependent on time is considered. Using the quasistationary derivative method, the analytical solution is obtained in the form of an explicit time dependence expressed as a combination of elementary functions.