Experimental Study on Metal Jet Spreading on Substrate With Roughness

Abstract The behavior of molten corium, particularly when it impinges upon the containment substrate and the further spreading, is important in determining the integrity of the containment structures. In nuclear power plants (NPPs), substrates typically display a variety of surface textures; however, the impact of substrate roughness on corium behavior remains inadequately explored. In this study, the influence of substrate roughness on the corium spreading behavior is investigated. A series of scaled experiments were conducted using Wood’s metal as corium simulant impacting substrates of different roughness levels. The heated corium simulant is discharged on the substrate (sandpaper or concrete) and this process is recorded by cameras. Based on the experimental results obtained, a model is proposed to predict spreading area considering both corium flow rate and substrate roughness. It is concluded that increased substrate roughness generally reduces the spreading area of corium. The results of these experiments provide valuable insights into how surface roughness influences the spreading behavior of corium, offering essential data for enhancing reactor safety measures and containment strategies.