Real-Time Nonlinear Estimation of Fuel-Clad Gap Conductance

Employing an extended Kalman filter, on-line estimates of gas gap conductance in a pressurized water reactor (PWR) fuel pin are obtained. A seventh-order, nonlinear model of a PWR is described. Implementing this model in the Kalman filter allows estimation of the reactor state vector, which includes gap conductance as an element. Using data from a test reactor facility, estimator performance is evaluated.