Self-propagating high-temperature synthesis (SHS) is a high-efficiency and low-cost thermal technology that uses the energy released during exothermic oxidation-reduction reactions to immobilize solid radioactive wastes

such as high-level radioactive calcined ash and contaminated soil. It is effective to increase the product's density and control the diffusion of the hazardous aerosol by using SHS immobilization in a sealed container. By the analysis of the chemical reaction mechanism and process of the SHS immobilization

the numerical simulation model for the in-container treatment was established and the variation characteristics of the temperature and pressure during the immobilization were studied. By using the COMSOL finite element analysis software with the preset model size

unit type and boundary condition

the in-container temperature-time and pressure-time variation curves in 7200 s after SHS ignition were solved. The simulation is compared with the experiment data in the same in-container immobilization condition

and the results have strong consistency and show staged difference among ignition

burning

flameout and thermal insulation of the SHS immobilization process. The numerical simulation conclusion could act as the reference data for the container safety design.