A compensator design controlling neutron flux distribution via observer theory

To suppress the spatial xenon oscillations in a nuclear reactor, an implementable stabilization scheme is proposed based on the finite dimensional compensator theory in control theory for the distributed parameter systems. The method is applied to a one-dimensional reactor whose dynamics is governed by one-group diffusion equation with its associated iodine and xenon dynamics. The modal decomposition of the state variables enables us to use the pole assignment algorithms developed in finite dimensional systems to obtain the stabilizing compensator gains. This allows us to estimate the states of a reactor in a transient using output measurement data and arbitrary initial conditions, and control the states using the estimated values. The resulting compensator is tested by using model-based data for measurement output through numerical simulations. The results show that unstable spatial xenon oscillations initiated by perturbations can be controlled by the finite dimensional compensator.