XT-ADS sensitivity analysis

This work has been carried out in the first period (March-June 2010) In which the author Joined the Central Design Team in Mol (B) for the CDT/FASTEF EU FP7 project. Before to start with the deep characterisation foreseen during the WP2 for FASTEF (100 MW LBE cooled reactor, working in both critical and sub-critical modes), a preliminary code tuning has been carried out by adopting the XT-ADS core layout (developed in IP EUROTRANS, EU FP6 project). The tuning deals with the neutronic codes, in particular: ERANOS (deterministic) and MCNPX (Monte Carlo). The main results have been included in the two SCK-CEN calculation notes here reported. The first calculation note (ANS/RMS/TS/ARTD00CDT-02/827/10-15) highlights the main differences between the ERANOS and MCNPX models for XT-ADS. Then the ERANOS input has been modified to consider the same assumptions adopted by MCNPX. A further tuning of both models yields, as a whole, a reduction of the MCNPX-ERANOS keff difference (at BoL) from by about 2700 pcm down to 1000 pcm. The second calculation note (ANS/RMS/TS/ARTD00CDT-02/827/10-16) summarizes the XT-ADS sensitivity analysis performed by ERANOS ver. 2.1 with two different nuclear data Iibraries: JEFF3.1 and ENDF/BVI.8. The study, carried out by exploiting the basics of standard perturbation theory, points out which nuclides, which cross-section and which range of energy yield the most significant impact on the core reactivity. As in the first note, the ERANOS evaluations (performed in a reference and voided configurations) have been compared with the results obtained with the MCNFX code.