Analisi di uno scenario di parziale congelamento del sistema primario

In the context of GEN-IV Heavy Liquid Metal safety studies, the lead freezing in the pool is considered one of the main issues to be addressed and a realistic accident for LFR. The present document is a first step towards a detailed analysis of such phenomena, and a CFD model and approach is presented to have a detailed thermo-fluid dynamic picture in the case of freezing. In particular, a numerical methodology is presented to model the freezing of lead and the heat transfer in a proper way. Then, the model is applied to the shell and tube Heat Exchanger of the NACIE-UP facility.