Secondary emission behavior analysis and aerosol characteristics evaluation in laser cutting for safe nuclear decommissioning.

We analyzed secondary emissions and aerosol characteristics generated during the cutting of 10-30 mm thick austenitic 304 L stainless-steel plates with a high-power fiber laser. This study comprehensively includes exhausted aerosols, sedimented dross, wall deposits, and attached slag. The amount of secondary emissions for each cutting process condition was determined by type. Over 98 % of the secondary emissions consisted of attached slag and sedimented dross, with wall deposits accounting for 0.5-1.4 % and exhausted aerosols for less than 0.1 %. As cutting thickness increased, the total amount of secondary emissions increased. The ratios of attached slag and sedimented dross varied depending on cutting speed and laser power. The count median aerodynamic diameter of aerosols was ∼0.12 µm when a 30 mm thick plate was cut with a laser power of 3 kW. Aerosol concentration decreased by nearly 30 % with increasing cutting speed, depending on conditions, suggesting that optimizing speeds can effectively reduce aerosol generation. Chemical composition analysis provides insights into aerosol reactivity, toxicity, and environmental impacts, aiding in the design of filtration and ventilation systems. These results are expected to reduce environmental and health impacts in nuclear decommissioning processes.