A fuzzy rule base for the improved control of a pressurized water nuclear reactor

In France, nuclear energy provides about 80% of the whole electricity produ ction. A modulation of the nuclear power plants must be able to respond to the demand on the network, The pressurized water nuclear reactor has to yie ld correctly a load set point. Fundamentally, two parameters are concerned in leading this task to a successful conclusion: the power axial-offset and the control rods position. The focus of this study is the automation of th e control of the power axial-offset by adding soluble boron and by minimizi ng the volume flows through the water pump. It is also important to take in to consideration the liquid waste volume, Water or boron is injected into t he reactor primary circuit. At the present time this task is still performe d manually by an operator, for all previous attempts to automate it failed. A nonfuzzy device, earlier developed by Electricite de France, was intensi vely tested at Cruas, France, power plant and allowed to prove the feasibil ity of automating the boration-dilution function. But it could not be defin itely adopted because it was too difficult to be tuned for industrial purpo se, That device, sketchily described in the paper, gave rise to the develop ment of a real-time fuzzy controller for the power axial-offset and the con trol rods insertion in a pressurized water reactor (PWR), The fuzzy control ler, which is the main subject of the paper, expresses more naturally the h uman expertise, thus avoiding the previous issue of empirical tunings. It w as implemented in simulation using Matlab-Simulink on a Sun workstation. Tw o realistic tests discussed show that the fuzzy controller runs as efficien tly as an expert operator does.