Coolant Flow Estimation in Natural Circulation BWR

This work presents the design and implementation of an advanced controller in real time for the estimation of coolant flows through fuel assemblies about standard neutron flux strings of a boiling water reactor (BWR) reactor core cooled by natural circulating water. During all operations of a natural circulating BWR, the fuel assembly's coolant flow is one of the main variables to consider. The goal of this advanced controller is to reduce penalties associated with operation limits established due to coolant flow uncertainties. The design of the controller was based on the theory of an extended Kalman filter. The estimator flow uses the equivalent electrical model, which was developed from the analogies between electrical current and voltage with coolant flows and pressure drops. Results obtained from computer simulations indicate that the best estimations of the total core flow are possible for the natural circulating BWR.