Multi-recycling in LWRs is a tangible solution moving towards the closure of the fuel cycle, but it presents some limitations related to the degradation of the Pu isotopic composition and the generation of minor actinides (MA), leading to an increase of vitrified high-level waste when compared to multi-recycling with Fast Reactors (FRs).
Significant improvement in converting all the Pu isotopes and MA into Fission Products (FPs) with shorter half-lives can be achieved with the introduction of advanced FR systems, among which the molten salt reactor (MSR) using Chloride salt is a particularly promising option. There is no experience to this date with Chloride MSRs (Cl MSRs) in operation, but they have been studied and tested on experimental set-ups, showing a great improvement in the conversion rate of actinides.
For these reasons, MIMOSA aims to develop an accessible, cost/risk optimised multi-recycling strategy of LWR spent fuels in the EU, based primarily on multi-recycling of Pu (and Reprocessed U) in LWRs combined with the Cl MSR, using already available infrastructure in the EU such as the French reprocessing plant in La Hague.
This strategy will also be compared with other multi-recycling scenarios and alternative reprocessing options.