2D and 3D numerical investigations of sodium boiling in sodium cooled fast reactor with MOX fuel and low sodium void reactivity effect during unprotected loss of flow accidents

Analysis of sodium boiling initiated by unprotected loss of flow in European sodium fast reactor core with different subassembly designs

“…This is achieved by the voiding of the plenum region, as a result of sodium boiling propagation upward from the fuel region of the subassembly (SA), and a corresponding decrease of neutron reflection towards the fissile fuel region. It has been previously demonstrated that such a design can result in a stabilized sodium boiling process, and subsequent power excursion can be evaded (Poplavsky et al, 2009;Raskach et al, 2021). The capability of this core design to keep the reactor stable during an unprotected accidental scenario is to be assessed in this study.…”