[en] Challenge: • Extremely valuable knowledge (Phénix and less from Creys-Malville): - fuel and core; - sodium technology and steel which can contain it; -components and operation of a SFR. • Progress can still be made: - to raise safety level (= 3rdgeneration); - performances (fuel, reactor, energy conversion). • Challenge: design futures SFR / requirements ~ PWR (availability, safety, cost, financial risk) + sustainability. • Operating feedback experience → improvements / (Phénix, CreysMalville, EFR) and innovations (R&D CEA, AREVA and EDF). • Passing on the knowledge and skills acquired in the past to men and women who will develop, design, construct and operate the future SFR.