Eigenvalue sensitivity and nuclear data uncertainty analysis for the Moroccan TRIGA Mark II research reactor using SCALE6.2 and MCNP6.2

Abstract In order to evaluate the impact of nuclear data on the reactor safety assessment, eigenvalue sensitivity and uncertainty analysis of the Moroccan TRIGA Mark II research reactor are evaluated in this paper. Using the SCALE package, a nominal criticality calculation was implemented in this work to assess the accuracy of the developed TRIGA SCALE model. The aim has been reached by comparing several neutronic parameters results with those obtained by the MCNP TRIGA model which has been performed in previous studies. To generate the sensitivity coefficients, two models of the TRIGA reactor were compared, including the averaged and detailed fuel models, based on the SCALE /TSUNAMI-3D sequence and MCNP/KSEN card. Comparison between those models was performed to evaluate and increase the efficiency of the sensitivity and uncertainty calculations. The obtained results show a good agreement between the TRIGA models studied in this work. Furthermore, the results of this analysis indicate that the uncertainty in the effective multiplication factor ( k eff ) is mainly awarded to uncertainties on the ν ‾ , χ , fission reactions of 235U as well as the moderator scattering and the clad absorption.