Development and application of computational fluid dynamics approaches within the European project THINS for the simulation of next generation nuclear power systems

• Thermal–hydraulic crosscutting issues related to Generation IV reactor concepts have been investigated within the European Project THINS.
• New nuclear systems are characterized by various non-unity Prandtl number coolants.
• Improvements in the turbulence modeling for innovative coolants have been achieved.
• Extensive development and validation work has been done.

Today computational fluid dynamics (CFD) is widely used in industrial companies, research institutes and technical safety organizations to supplement the design and analysis of diverse technical components and large systems. Such numerical programs are applied to better understand complex fluid flow and heat transfer phenomena. In the last decades there is an increasing interest in the nuclear community to utilize such advanced programs for the evaluation of different nuclear reactor safety issues, where traditional analysis tools show deficiencies. Within the FP7 European project THINS (Thermal Hydraulics of Innovative Nuclear Systems), CFD and coupled 1D-3D thermal–hydraulic simulations are being carried out. These are dedicated to the analysis of the thermal–hydraulics of gas, liquid metal and supercritical water cooled reactors. Such concepts utilize innovative fluids, which have different properties from the ones used in the current nuclear reactors. In order to improve the thermal–hydraulic predictions of their behavior, CFD development, application and validation activities are performed within THINS. This overview paper highlights some of the CFD related work within the European project.