The main objective of the CDT project is to establish an engineering design of a Fast Spectrum Transmutation Experimental Facility (FASTEF) that is the pilot plant of an industrial-scale of both an Accelerator Driven System (ADS) and a Lead Fast Reactor (LFR), based on the MYRRHA reactor concept, planned to be built during the next decade. An important issue regarding the reactor design of the MYRRHA/FASTEF experiment is the in-vessel fuel storage facility for fresh fuel, as it might have an impact on the criticality of the overall system that must be analyzed and quantified. In this work, the neutronic analysis of the in-vessel fuel storage facility and its coupling with the critical core was performed, using the state of the art Monte Carlo program MCNPX 2.6.0. Using this program several parameters were analyzed, like the criticality behavior (namely the Keff), the fission power production and the radiation damage (the displacements per atom).