Overview of French RandD on SFR MOX fuel fabrication

International audienceThe manufacturing of the (U,Pu)O$_2$ mixed fuel pelletsdesigned for SFR are being conducted by the frenchactors CEA with support from ORANO and EDF,carrying out an approach covering all the manufacturingsteps, from the implementation of the UO$_2$ and PuO$_2$actinide oxide powders to the pellet sintering. A referencefabrication process has been proposed, considering theexperience feedback from fuel manufacturing for Phénixand SuperPhénix reactors. The recent developments dealwith the increase of the Pu content (up to 30%) and theeffects of aged Pu (thermal and radiolytic effects) whichare among the main challenges to sustain the closed fuelcycle. The R&D focuses firstly on experimental studies todeepen the understanding phenomena involved in thereference process. Further, a physical modelling isdeveloped to build a simulation tool in order to improvethe performance of each manufacturing steps in a lab-toplant approach. Modelling and simulations are based onspecific experiments (grinding and mixing process,mechanical measurement on tailored actinide powders,microscopic characterisation…).Advances has been achieved in the understanding andmodelling of physical phenomena describing thephenomenology of each steps. However, numerouschallenges remain today in the modelling