CATHARE-3: A new system code for thermal-hydraulics in the context of the NEPTUNE project

Abstract

After a thorough analysis of the industrial needs and of the limitations of current simulation tools, EDF and CEA (Commissariat à l’Energie Atomique) launched the NEPTUNE Project in 2001 (see Guelfi et al., 2007) with the support of AREVA-NP and IRSN. The NEPTUNE activities include software development, research in physical modeling and numerical methods, development of advanced instrumentation techniques and new experimental programs. Four different simulation scales were addressed including DNS (Direct Numerical Simulation), CFD in open medium (Computational Fluid Dynamics), component (subchannel-type analysis) and system (reactor modeling) scales. In 2006 CEA, EDF, AREVA-NP and IRSN defined the strategy for the system scale of NEPTUNE and the CATHARE-3 development was launched. The main objectives are: • advanced physical modeling of two-phases flows, mainly by using multi-field and turbulence models, • improved 3D modeling by the use of fine and non conforming structured meshes, • generalized coupling capabilities with other thermal-hydraulic scales and with other disciplines (core physics, structural mechanics, …), • extension of the applicability to new Gen IV reactors (Sodium Cooled Fast Breeder Reactors, Gas Cooled Reactors, Supercritical Light Water Reactors), • a true object-oriented code architecture. At the same time CATHARE-3 is in continuity with the CATHARE-2 code which is the current industrial version of CATHARE and internationally used for nuclear power plant safety analysis, in simulators and in coupled simulation tools. The road map of these two codes will allow a smooth transition from CATHARE-2 to CATHARE-3 for all users. This paper gives an overview of the choices made for the development of CATHARE-3 including new physical models, validation strategy and experimental programs, numerical improvements, enhanced coupling capability and software architecture evolution. The current status of the project as well as the overall schedule will be presented.