Aerosol generation characteristics during laser cutting of carbon and stainless steel surfaces for nuclear power plant decommissioning

The decommissioning of the Fukushima Daiichi Nuclear Power Plant presents significant challenges due to high radiation levels and the need for safe and efficient fuel debris retrieval. Laser cutting is a promising technique for decontamination and dismantling, but it generates submicron-sized radioactive aerosols, necessitating precise aerosol management strategies. This study investigates aerosol generation during laser cutting of carbon steel (CS) and stainless steel (SS) surfaces under varying power levels and surface coatings at the Mitsubishi Heavy Industries Ltd. (MHI) Research & Innovation Center utilizing class-4 laser. Experimental results indicate that increasing laser power leads to higher aerosol concentrations, particularly for larger aerosols, while smaller aerosol concentrations decline. This effect is more pronounced in CS surfaces than in SS. Coated surfaces, especially with zirconium dioxide (ZrO 2 ), exhibit higher aerosol generation at elevated power levels, suggesting an intensified laser-material interaction. The experimental results highlight the role of coating composition in aerosol generation and importance of dispersion control methods during decommissioning. The analysis of aerosol dispersion results can give insight to enhance radiation worker safety, protect sensitive electronics, and improve the effectiveness of remote laser-based decontamination in high-dose environments.