Molten Salt Fast Reactor (MSFR) is an innovative and challenging reactor concept in the frame of Generation IV International Forum. The unique and distinctive feature of MSFRs is the liquid state of their fuels, which call for new safety systems that should be studied, as the Emergency Draining System. Molten salt fuel draining is a research activity in the frame of SAMOFAR project. Thesis objective is to provide an accurate description of core dynamics during a fuel draining. In case of emergency, the salt could be drained out from the core, actively or passively triggered by melting of salt plugs, and stored into a draining tank underneath the core.