The fabrication and irradiation of plutonium-containing inert matrix fuels for the ‘Once Though Then Out’ experiment

Seven plutonium containing inert matrix fuel (IMF) capsules were prepared for an irradiation experiment in the high flux reactor. In the irradiation experiment, named once-through-then-out, both spinel-based and zirconia-based targets are irradiated up to a plutonium burnup of about 200 GW d m−3, corresponding to a Pu depletion of 50–60%. Both micro and macrodispersed spinel targets are tested, the zirconia targets are of the homogeneous type. In this paper, the fabrication routes of the IMF pellets for this irradiation are described in detail. The results of the dimensional measurements, density measurements, ceramographies and X-ray images of the samples are given. Some preliminary results of the irradiation are included.