1. Introduction 2. Dynamic and historical vision of severe accident approach in SFR former projects 3. Overview of ASTRID and JSFR design 4. Approach and study methodology for mitigation of severe accidents by design proposed by CEA 5. Severe accident calculation tools used for severe accident and mitigation studies 6. Mitigation studies carried out for the French SFR demonstrator 7. Japanese reactor prototype approach and studies, illustration on other recent SFR concepts 8. Further R&D needs 9. Conclusion