“…In these investigations, in general, the initial debris bed sh supposed to be homothetically piled [37], cylindrical [38], heap-like [40,41], and G shaped [39] or conical [16,[42][43][44]. Nevertheless, it was found that the geometries o beds (such as their heights) also significantly affect their heat removal capacity [4 the past few years, by assuming that the bed was initially conical (or convex), e investigations on the relocation phenomena of debris beds (termed as self-leveli gered by sodium boiling were performed [14,15,43,44,[47][48][49][50]. Based on these in tions, the self-leveling mechanisms (e.g., bubble-particle interactions within partic and characteristics (e.g., parametric influence on the leveling rate) were clarifie ever, it should be noted that the complex multiphase flows, including solid debri coolant, and sodium vapor, involved in the DBF process can result in varyin shapes of the debris bed, which in turn can influence the progression of severe a in SFRs.…”