Outcomes of the FP-7 project PELGRIMM investigating pelletized and sphere-packed oxide fuels for Minor-Actinides transmutation in a Sodium Fast Reactor.

Overview & Synopsis

PELGRIMM 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 UO$_2$ fuels located in radial core blankets, are under consideration. The objectives of the project are to capitalize on efforts made within the previous European projects ACSEPT, FAIRFUELS, F-BRIDGE as well as CP-ESFR, 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 related to first results on helium and fission gas behaviour in (Am,U)O$_2$-x fuels irradiated in the separated effect test MARIOS; progress status of the semi-prototypic irradiation MARINE under preparation, that will provide a comparison between sphere-packed and pelletized (U,Am)O$_2$-x fuel performances; investigations performed to extend Minor Actinide bearing fuel fabrication processes to alternative routes, that are the 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; and finally, progress related to the key issues of core physics, design and safety performance for sphere-packed MA-bearing driver fuels.