The Multi-Physics Modelling Approach Oriented to Safety Analysis of Innovative Nuclear Reactors;pp. 171-214
Authors: (Antonio Cammi, Valentino Di Marcello, Lelio Luzzi, Vito Memoli, Politecnico di Milano, Department of Energy, CeSNEF (Enrico Fermi Center for Nuclear Studies), Milano, Italy)
Abstract: In this chapter, the Multi-Physics Modelling (MPM) approach to the study of nuclear reactor dynamics is discussed. Based on the several activities (of development and validation) carried out at the Politecnico di Milano, MPM reveals a useful tool when dealing with reactor safety and control, and can be considered as an integrative analysis implement in the design process of reactor layout. The MPM fundamental feature is represented by the capability to simultaneously solve the coupled equations, which govern the different physical phenomena occurring in a nuclear reactor in the same simulation environment. This prevents the safety analyst from implementing additional code pieces for coupling neutron kinetics and thermal-hydraulics codes. Moreover, the Coupled Code Techniques (CCT) can require significant modifications of the considered codes. On the contrary, the adoption of a MPM tool allows the analyst to minimize the programming burden and to focus on the physical aspects of the problem. An important advantage given by the employment of such MPM approach is the possibility to perform more accurate thermal-hydraulic simulation by using computational fluid dynamics schemes comprising the description of turbulent flows, which occur in the majority of nuclear reactor cores.