Numerical investigation of spreading phenomena of molten corium using EISPH method

Understanding the behavior of molten corium is crucial for effective heat management and ensuring the integrity of reactor containment during severe nuclear incidents. Corium spreading is a complex multi-physics phenomenon influenced by hydrodynamics, heat transfer, and phase change. The Smoothed Particle Hydrodynamics (SPH) method is utilized to study corium flow, leveraging its ability to handle complex fluid dynamics and its compatibility with parallel computing architectures. This research examines two specific corium spreading cases: the VULCANO VE-U7 experiment, which is characterized by a wide mushy zone, and the FARO L26S experiment, noted for its narrow mushy zone. The study compares spreading lengths and temperature profiles over time with experimental data, offering a detailed analysis of the observed spreading behaviors. Variations in physicochemical properties result in distinct spreading patterns between the cases, highlighting the complexity of corium behavior under different scenarios. The findings demonstrate the applicability and capability of the SPH method in capturing various characteristics of corium spreading effectively. • Corium spreading is a complex multi-physics phenomenon characterized by free surface flow and influenced by an array of physical processes such as hydrodynamics, heat transfer, and phase changes. • An implicit viscosity solver has been integrated into the Quasi-Lagrangian Explicit Incompressible Smoothed Particle Hydrodynamics (EISPH) method to effectively handle the highly viscous nature of corium. • The study numerically investigates two corium spreading phenomena with different physicochemical characteristics: VULCANO VE-U7 and FARO L26S. • The applicability and capability of our Smoothed Particle Hydrodynamics (SPH) method to model various corium spreading phenomena have been demonstrated both qualitatively and quantitatively, particularly in aspects related to fluid dynamics, heat and phase change.