Advanced fast reactor development requirements: Is there any need for HEU?

The present paper reviews R&D needs foreseen for advanced fast reactor development. The focus is on physics, safety and fuel validation needs using experimental facilities, i.e. critical zero power facilities or irradiation reactors. This review underlines the crucial need for a continuous availability of such facilities in the next decades. As for the fuel to be used in the experiments the need is for plutonium fuelled experiments and no specific need for HEU seems to be foreseen. However, the already existing stocks of HEU at some critical facilities like MASURCA in France will be certainly needed and should be kept in order to allow the required flexibility to perform critical experiments of large size, representative of most future advanced systems.