Measurement and Analysis of the Concentration and Size Distribution of Welding Fume in a Confined Space

Abstract

This paper aims to present the measurements and analysis results of welding fume concentration and particles character in nuclear island containment. The concentration of fume exposure is measured by using CCZG-2A portable personal fume meter and CEL-712 fume detector. In addition, the morphology, element composition, and particle size distribution of fume particles are analyzed through high-resolution transmission electron microscope (TEM) and energy-dispersive spectroscopy (EDS). The results show that (1) there are mainly three types of fume particles in the confined space of nuclear island, namely spherical metal particles with particle size of 0.3–2 μm, non-metal particles with particle size of 1 μm, and welding primary and secondary fume particles with particle size of several nanometer to microns. (2) On the one hand, welding workers’ individual fume exposure exceeds the standard rate by 75%, and the highest concentration exceeds the standard by more than 6 times. On the other hand, the possible welding exposure of non-welders is also beyond the standard rate, which exceeds the prescribed limit rate between 3 and 16 times. (3) Welding fume particles in confined space of nuclear island are located in the accumulation mode with particle size of 0.08–2.0 μm. The median diameter of the particle number is 0.3 μm, in which the particles account for 67% of the total particle number in the range of 0.15–0.6 μm, and 95% of the total particles in the range of 0.07–1.24 μm. The results of this study will provide support for computational fluid dynamics (CFD) numerical simulation of nuclear island welding fume decontamination in the next step.