Aerodynamic and chemical characterization of radioactive aerosols for size-dependent internal dose assessment

Abstract

Radioactive aerosols are one of the main sources of internal radiation exposure to workers and surface contamination in the workplace during the decommissioning of nuclear power plants. The particle size distributions of radioactive aerosols are important for predicting radiological risk, improving radiation protection, and preventing surface contamination. This study measures the particle size distributions of aerosols produced from cutting various metal in different cutting conditions (cutting speed, metal thickness) using plasma arc cutting. Real-time sampling and in-situ characterization of aerosols were achieved at a high resolution of 500 stages from 6 nm to 10 μm considering isokinetic sampling and automatic cutting. The chemical compositions of aerosols were analyzed for major matrix elements along 13 different stages. Size-dependent dose coefficients were compared with the international commission on radiological protection reference dose coefficient 5 μm activity median aerodynamic diameter value. The research on nuclide mass contained in aerosols and the dose coefficient by changing the cutting conditions suggested cutting strategies to minimize internal exposure of workers.