CFD Assessment of Pool Thermal-hydraulics for HLM Reactors

European lead fast reactor designs are all pool-type designs. The pool basically forms the primary system of the reactor and as such plays a crucial role in the design and safety analyses of such reactors. The safety analyses require thorough understanding of the flow and heat transport in the primary system. In the past, the design and safety analysis of liquid metal cooled reactors highly relied on design specific experimental set-ups using either a transparent, easy-to-handle simulant fluid relying on scaling analyses or using liquid metals while coping with measurement limitations. Nowadays, Computational Fluid Dynamics (CFD) has become an integral tool of the advanced reactor designer allowing simulations in 3 dimensions. However, in a heavy liquid metal pool, many complex physical phenomena come together. As such, these simulations need separate validation of the capabilities of the applied CFD codes and, on top of that, integral validation using large scale experimental facilities. This paper discusses the ongoing efforts at NRG in the Netherlands on validation of CFD tools for heavy liquid metal pool simulations with respect to flow and heat transport.