In case of postulated Sodium Fast Reactor severe accidents, the core could melt and form a mixture called corium. In this event, sacrificial materials could then be used to reduce the heat load to the retention structure and to avoid the criticality risk. This approach was applied in the past with, for instance, depleted uranium oxide used as sacrificial material in the SNR300 ex-vessel core catcher. A review of sacrificial material candidates has been conducted, considering both neutron absorber and diluent materials. This review was initially based on criteria related to thermophysical and chemical thermodynamic properties (melting and boiling temperature, ability to form a liquid solution with molten fuel...). Neutronic calculations have been done for some generic configurations in order to estimate the reactivity decrease due to the mixing of corium with some different materials. Materials such as aluminium oxide, uranium oxide and hafnium or europium oxides will be presented in more details and their relative advantages discussed.
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