Numerical Investigation of Aerosol Generation by Laser Decontamination and Aerosol Removal by Spray Based on OpenFOAM

During the maintenance and decommissioning of nuclear facilities, laser decontamination technology can be utilized to clean the radioactively contaminated surfaces inside the primary containment vessel. However, a significant amount of sub-micron radioactive aerosol particles will be generated during the laser decontamination operations. To prevent these radioactive substances from leaking into the environment, the containment spray system can be employed to remove these submicron aerosol praticles. To investigate the physicochemical properties of the aerosols produced by laser decontamination and the efficiency of aerosol removal by spray droplets, the laser decontamination experiments were firstly conducted to measure the aerosol characteristics such as aerosol generation rates, concentrations, and particle diameter distributions. Subsequently, a CFD model was developed and implemented into OpenFOAM to simulate both the aerosol generation by laser decontamination and aerosol removal by spray droplets using Euler-Lagrange approach, and the characteristics of aerosol generation, migration and diffusion and removal by spray in an enclosed space were simulated and analyzed. The simulation results demonstrate that aerosols within the spray region can be directly removed by interacting with the spray droplets, while those in the non-spraying region need to be entrained into the spray region with the airflow movement and then removed. Furthermore, it was observed that the larger the aerosol particle size, the higher its spray removal efficiency. The numerical simulation model established in this study can be served as a foundation and technical reference for future optimizations of laser decontamination and aerosol removal by spray in enclosed space.