Characteristics of metallic uranium aerosols generated under fire conditions

• A set of aerosol generation test equipment is designed. • The formation of aerosol of rare metal uranium was studied by means of experimental equipment. • With kerosene as fuel, temperature control is easier. Radioactive aerosol will enter the human body through the respiratory system, digestive system and other ways, seriously endangering human health. At present, there are few public reports on the generation of uranium aerosol under combustion conditions, and the experimental conditions in the existing reports differ greatly, resulting in limited reference significance. Therefore, a set of uranium aerosol experiment equipment is designed in this work, and the formation characteristics of two kinds of metallic uranium aerosol under fire conditions are studied. Thus, the information on the particle size distribution, RF (Respirable Fraction), ARF (Airborne Release Fraction) of uranium aerosols was obtained. The results indicate that particle size of two uranium aerosols exhibited log-normal and bimodal distributions, respectively, while the RF values were similar and close to 1 in both cases. The ARF values for combustion products with different compositions exhibited a high degree of similarity. Based on our experiments and literature data, the results suggests that the particle size distribution of uranium aerosols is influenced by the composition and structure of the material significantly, and the ARF is impacted by the specific surface area of the materials.