In this paper, a new concept of the Reactivity Trace Curve (RTC) for reactor power control is presented. The concept is demonstrated for a reactor model with one group of delayed neutrons, where the reactivity trace curve is simply a closed form exponential solution of the RTC-differential equation identifier. An extended reactor model of multigroup (six groups) of delayed neutrons is discussed for power control using the RTC-method which is based on numerical solution of the governing equation...