Status of CEA studies on spallation target materials for the neutron source of accelerator driven systems

Abstract
In the framework of the GEDEON Materials workshop, and of the CEA studies on accelerator driven systems (ADS) dedicated to nuclear waste transmutation, a liquid metal reference concept and an alternative solid target have been evaluated to produce neutrons inside the spallation module. This work examines the design (neutronic, thermohydraulic and mechanical aspects) and the performance of both options. It is shown that a liquid PbBi target offers more possibilities with respect to high proton current densities (possible industrial extrapolation) but that a solid target made of tungsten particles also offers an interesting ability to create a neutron flux appropriate (hard spectrum and flat axial distribution) for a sub-critical core dedicated to incineration.