Fault Monitoring and Accommodation of the Heat Exchanger Parameters of Triga-Mark II Nuclear Research Reactor using Model-Based Analytical Redundancy

One of the major challenges in instrumentation is to identify wrong data (signal) measurements and perform their validation. This can be done by regularly ensuring a correct operation of the different process components, particularly those having great importance for safety, in order to detect, isolate and identify any possible degradation or fault. This operation, known as on-line fault monitoring, should be done as early as possible, before any fault causes failure in equipment which can lead to the downtime of the plant and even to severe catastrophes and disasters. Therefore, these consequences influence negatively on productivity, availability and environment. At Triga-Mark II nuclear research reactor, the heat exchangers are provided for removing generated heat from the reactor pool water throw cooling circuits. Therefore, the monitoring of the evolution of thermo hydraulic parameters is necessary to ensure the safety of the reactor. Among several developed techniques, analytical redundancy has been recognized as an effective method for fault monitoring. It is the process of identifying a faulty instrument in a system through a comparison of its output to an estimate data. This estimation is based on the model and the measurements provided by the data acquisition chains of the existing sensors during all the operating modes of the installation. In our case, we are limited to mathematical models and Kalman filter approaches. In this paper we review the state of the fault monitoring and some model based analytical redundancy techniques for the heat exchanger, and present experimental results on their application to temperatures and flow rates of the cooling system of Triga-Mark II research reactor core.