Computer Control of the Halden Boiling Water Reactor Part II: Reactor Plant and Core Control

Abstract

At the OECD Halden Reactor Project advanced control methods have been applied for on-line control of the main plant variables and of the power distribution in the reactor core.For the control of the plant variables, which comprise the integral nuclear power and the reactor vessel pressure, a control algorithm was developed which is based on a linear, time-invariant model of the reactor and its heat removal circuits. The algorithm is optimized with respect to a quadratic performance index. Kalman filtering technique was used for the estimation of inaccessible state variables.The performance of the control system was tested in reactor experiments. Different perturbations were introduced to the reactor plant and the behaviour of the controlled process was observed. The results indicate that the chosen control method is promising with respect to applying it to nuclear power plants.As a parallel project, an on-line control procedure was developed for the spatial distribution of the power generation in the reactor core. The chosen method implies the continuous estimation of the present state of the process and of the state-dependent process parameters. From this information a feedback function is evaluated which converts the deviation between actual and desired distribution into a control rod pattern which yields an optimal approximation of the de sired power distribution.