Investigation of the void reactivity effect in large-size Lead Fast Reactors

► Void reactivity effect not completely resolved for HLMC symstems yet. ► Clear identification of the physical mechanisms involved in LFR coolant voiding. ► Range of variability of the neutronic parameters impacting reactivity variations. ► Assessment of global reactivity variation and breakdown by nuclides and reactions. ► Comparison between various deterministic schemes and Monte Carlo methods.