Fabrication and characterisation of U0.85Am0.15O2−x discs for MARIOS irradiation program

This paper describes the developments and results of the fabrication of Am bearing blankets for the MARIOS experiment in the High Flux Reactor (HFR, Petten). This irradiation program aims to asses the influence of the microstructure on the helium release and then fuel swelling for different irradiation temperatures during heterogeneous transmutation mode. In this context, two types of microstructures, dense and tailored porosity, were investigated. The materials were fabricated by a pelletizing–sintering process in the ATALANTE facility. Moreover, dedicated tools were developed to respect the specifications imposed by the program. The results of fabrication indicate that the characteristics of the discs are within the specifications except for open porosity ratio which remains too high for the dense materials.