• control
• MYRRHA
• RELAP5-3D
• Simulink

The main purpose of this Master Thesis consists in analyzing part of the control systems foreseen for the MYRRHA plant by the use of both graphical programming language and system code calculations.
MYRRHA is a fast spectrum irradiation facility under development at SCK•CEN in Mol, Belgium. In the framework of new nuclear reactor studies, MYRRHA project contributes to the demonstration of ADS applications and to material testing for GEN IV and fusion reactors, representing an experimantal plant for Lead Fast Reactor technology.
The first part of the work was devoted to the development of a RELAP5-3D model of MYRRHA, in its last design configuration. Even if a detailed model of the plant was already present, there were two main reasons to develop a new one: first of all, the mastery of the code and in particular of an own-made model would not have been possible adopting an already existing one. Secondly, some technical choices were made in order to simplify the computational weight of the calculation, i. e. a reduced number of volumes in the discretization of the plant system.
In the second part of the work, a dynamic analysis of the reactor was performed in Matlab – Simulink enviroment. The components requiring, to be properly represented, only single phase balance equations, have been developed through differential equation implementation, while two-phase systems have required a different approach.
Point neutron kinetics equations are used in order to describe the power generated in the core: this is basically the same approach followed by RELAP5 – 3D neutronics analysis.
Among the different control systems implemented, the study has been mainly focused on the secondary pressure regulation and the power control by means of the control rod (reactivity) system.