Experimental study on design optimization of the core catcher for the CEFR

In severe accidents, sodium-cooled fast reactors (SFRs) are more concerned with core disruptive accidents (CDAs), and in-vessel retention (IVR) is an important mitigation measure to ensure the integrity of the reactor vessel. The distribution and accumulation uniformity of the melt in the lower chamber seriously affects the residual heat discharge capability. The installation of a core catcher is an effective mitigation method, and its structure and arrangement play a key role in mitigating severe accidents. In this study, the experimental facility is designed based on the core catcher of the China Experimental Fast Reactor (CEFR). An experimental platform is established to simulate the falling and relocation of melts in the core catcher under the condition of CDAs. At the same time, a quantitative evaluation index is established to analyze the influence of the number of chimneys, the inclination angle of the chimney canopy, the central chimney height, and the spacing of chimneys on relocation of melts in the core catcher. Finally, some suggestions for correlation optimization design are given.