Experimental and numerical simulation study on the combustion characteristics of nuclear-grade activated carbon

This study presents a systematic investigation of the fire-risk characteristics of nuclear-grade activated carbon under the operational conditions of iodine adsorbers. A self-designed combustion experimental platform was developed to simulate the operational environment of iodine adsorbers, and a combustion kinetic model coupled with numerical simulations was established to elucidate the evolutionary behavior of activated carbon combustion. The experimental results demonstrate that during the initial smoldering phase, activated carbon reaches localized temperatures exceeding 700°C. The release patterns of CO and CO₂ exhibit significant correlations with combustion intensity, enabling their dual-parameter utilization as early-warning indicators for fire detection. The constructed mathematical model achieved a prediction error below 10% during the smoldering phase, effectively validating the theoretical hypothesis of pyrolysis-oxidation coupling mechanisms. These findings provide important data for optimizing fire-monitoring technologies in nuclear facility adsorbers, and the proposed gas concentration gradient-based warning strategy provides a theoretical foundation for the development of intelligent alarm systems.