Conference Agenda

The complexity in nuclear reactor safety issues has highlighted the need for more flexible and robust modeling approaches. Particle-based methods—such as Smoothed Particle Hydrodynamics (SPH), Discrete Element Method (DEM), and Lagrangian Dispersion Model (LDM)—offer significant advantages in modeling highly nonlinear, multiphase, and multiscale phenomena that challenge conventional grid-based methods. This paper presents the basic principles of these particle-based techniques and discusses their implementation within high-performance computing (HPC) environments, with an emphasis on graphical processing units (GPU)-based parallelization strategies. The capabilities of particle-based frameworks are demonstrated through a series of nuclear safety applications, including in-vessel retention and external reactor vessel cooling (IVR-ERVC), corium spreading, core catcher impact analysis, steam explosions, and environmental radionuclide dispersion. These case studies illustrate the methods' potential to handle complex interfaces, large deformations, and strongly coupled multiphysics interactions without explicit interface tracking. The paper concludes by outlining current limitations—such as computational cost, turbulence modeling, and phase-change physics—and suggests future directions toward establishing particle-based approaches as integral tools for next-generation nuclear safety analysis.