Progress status on pelletized and sphere-packed Am-bearing oxide fuels developments

International audiencePELGRIMM that stands for PELlets versus GRanulates: Irradiation, Manufacturing, Modelling, is a 4 years European project started in 2012, that investigates Minor Actinides - bearing fuels, shaped as pellets and beads, for Sodium Fact Reactors. Both Minor-Actinide transmutation options: the MA homogeneous recycle in driver fuels and the MA heterogeneous recycle on UO2 fuels located in the radial core blankets, are under consideration. The objectives of the project are to capitalize on efforts made within the previous European projects: ACSEPT (2008-2012), FAIRFUELS (2009-2014), F-BRIDGE (2008-2012) as well as CP-ESFR (2008-2013), and to take a new step in the long range qualification approach regarding fabrication process, irradiation behaviour, performance and safety, for pelletized and sphere-packed shaped Am-bearing fuels. The paper gives an overview of the PELGRIMM outcomes at mid-term, such as:- first results on helium behaviour in (Am,U)O2-x fuels irradiated in the separated effect test MARIOS- the progress status in the preparation of the semi-prototypic irradiation MARINE, to be performed in HFR, that will provide a comparison between sphere-packed and pelletized (U,Am)O2 fuel performances- investigations to extend Minor Actinide bearing fuel fabrication processes to alternative routes: Weak Acid Resins and micro-wave technologies, in order to limit secondary waste streams- upgrades in calculation codes used to describe conventional fuels behaviour under irradiation, taking into account the specific issues related to MA-bearing fuels and sphere-packed fuels-advances related to the problematic of core physics, design and safety performance for sphere-packed MA-bearing driver fuels.The paper finally gives an outlook on the next steps and milestones to be achieved