Tracking simulator model of nuclear power plant

Main purpose of this report is to present shortly the contents of the Master's Thesis' where one possible concept of a tracking simulator was considered. In the thesis a tracking simulator was developed based on controlling certain state variables chosen by using expert knowledge on nuclear safety analysis. Thesis was supported by the W0 Power Engineering Ltd. and Technical Research Centre of Finland. In this thesis the tracking simulator was a simulation model, driven alongside a 'real plant' in real time and the state of which was kept as close as possible to the state of the 'real plant'. In the thesis the 'real plant' was also a simulation model. The results of tracking can be used to improve the quality of measurements and therefore to enhance the knowledge of the real state of the plant. A special requirement for the realised tracking simulator was that it should be able to generate an accurate initial state for a simulator, which predicts the behaviour of the plant in the future. The basic principle in setting up the tracking simulator was to choose a small number of 'real plant' variables which were assumed to define the thermal hydraulic state of the plant. These variables were called the main variables. The values of the main variables were the target, towards which the values of the corresponding variables of the tracking simulator were driven. To achieve this goal the main variables of the tracking simulator were either controlled directly or guided by modifying the simulation model parameters affecting them. Furthermore the control actions made by the operators and plant automation system were taken into account when implementing the tracking simulator. The underlying idea of setting up a test bench was the fact that many industrial processes can be modelled very accurately and in real time using present day simulation tools. Also, the automation systems can be connected directly to the simulation models. In this test case both the tracking simulator and 'real plant' model were realised by using Apros simulation software, which offers the necessary models and communication facilities. The modelled process was the primary side of a VVER-440 nuclear power plant. The 'real plant' model was based on a detailed six equation thermal hydraulic model, while the tracking simulator had a simpler homogeneous thermal hydraulic model with heavily simplified nodalization. This set-up was considered to represent closely enough the situation between a real process and a simulation model.