Sensitivity and uncertainty analyses for advanced nuclear systems (ALFRED, ASTRID, ESFR and MYRRHA)

Within the frame of the EU H2020 program SANDA project, sensitivity and uncertainty analyses have been performed for the ESFR, ASTRID and ALFRED reactor concepts and the multi-purpose flexible irradiation facility MYRRHA. Relevant reactor parameters, namely the effective multiplication factor, the effective delayed neutron fraction, the Doppler reactivity coefficient, the void worth and the worth of control rods have been investigated. SCALE, Serpent 2 and MCNP6.2+SUMMON codes together with the covariance data of the JEFF-3.3 nuclear data library have been used for this study. A ranking of the most important isotopes and reactions impacting the mentioned parameters has been derived for all these systems. Uncertainties have been quantified and have been found to be higher than the target accuracies proposed. Therefore, recommendations for improvement of nuclear data are given.