Development of CFD models and pre-test calculations for thermal-hydraulics and freezing experiments on Lead coolant

Heavy Liquid Metals (HLM) are objects of interest in the nuclear research sector because of their optimal thermal and neutronic properties; the development and the validation of models allowing to predict their behaviour are fundamental for the future development of the Generation IV energy systems. An experimental facility named SESAME-stand, is planned to be operated at Research Centre Rez (RC-Rez) under the framework of SESAME project. The aim of the facility is to study the solidification of Lead under GEN-IV Heavy Liquid Metal pool type nuclear reactors relevant conditions and to provide a database for the benchmarking and validation of numerical models. Corresponding CFD models are developed using commercial software and are used for the pre-test assessment and to support the experimental work. The aim of this paper is to describe the CFD models, explain how they are tested and used in order to define a valuable experimental matrix that will be needed in order to run the facility itself. First of all, the facility is introduced together with the range of foreseen investigations. The numerical models are then presented. Emphasis is given to the geometrical and physical assumptions. Different approaches of modelling are compared and discussed. Results from the pre-test simulations are illustrated. Encountered challenges and their relevance with regard to the experimental matrix and setup are commented.