European thermal-hydraulic progress for sodium and lead fast reactors

Liquid metal cooled reactors are envisaged to play an important role in the future of nuclear energy production because of their possibility to use natural resources efficiently and to reduce the volume and lifetime of nuclear waste. Liquid lead(-alloys) and liquid sodium are good candidates for cooling such reactors. Thermal-hydraulics of these liquid metals plays a key role in the design and safety assessments of these reactors. Therefore, this is the subject of two large European collaborative programs, i.e. the Horizon 2020 SESAME and the MYRTE projects sponsored by the European Commission. This paper will present the progress in these projects with respect to liquid metal cooled reactor thermal-hydraulics. The main topics to be addressed are liquid metal heat transfer, fuel assembly thermal-hydraulics, pool thermal-hydraulics, and system thermal-hydraulics. With respect to liquid metal heat transfer, the purpose is to start from the most promising routes and develop and verify a model which can simultaneously deal with different flow regimes (natural, mixed, and forced convection). To this purpose new reference data, both experimental and high-fidelity numerical data is being generated. Considering fuel assemblies, the aim is to take the next steps in liquid metal fast reactor fuel assembly modelling, mainly focusing on validation and evaluation of accidental conditions. Again here, experiments and numerical simulations go hand in hand. With respect to pool thermal-hydraulics, the purpose is to develop and validate sufficiently accurate methods to model the coolant behavior in a liquid metal reactor pool including solidification behavior. And finally, when considering the system scale, similarly, the purpose is to validate and improve system thermal-hydraulics models and codes, but also to further develop and validate multi-scale approaches under development. © 2016 Association for Computing Machinery Inc. All Rights Reserved.