Optimal Power Control of a Nuclear Reactor by means of an Inverse Model

The control of nuclear reactor operation during instationary operating states is connected with high demands to process control in order to guarantee nuclear safety every time. Especially during start-up, a dynamic nonlinear process with power changes over several decades, the restriction of the reactor period is to be observed. In this connection problems of time-optimality have to be solved. Based on the point-kinetic equations an inverse reactor model has been derived. It permits to calculate such a control variable, the reactivity ς , which produces the wanted period T as the reactor output signal. By means of this inverse model a reactor period controller with a superposed power controller has been developed and realized by a microcomputer. The experiments with the zero-power reactor RAKE show that the controller is able to control both the reactor period and the power.