Uranium aerosols at a nuclear fuel fabrication plant: Characterization using scanning electron microscopy and energy dispersive X-ray spectroscopy

Detailed aerosol knowledge is essential in numerous applications, including risk assessment in nuclear industry. Cascade impactor sampling of uranium aerosols in the breathing zone of nuclear operators was carried out at a nuclear fuel fabrication plant. Collected aerosols were evaluated using scanning electron microscopy and energy dispersive X-ray spectroscopy. Imaging revealed remarkable variations in aerosol morphology at the different workshops, and a presence of very large particles (up to ≅ 100 × 50 μm²) in the operator breathing zone. Characteristic X-ray analysis showed varying uranium weight percentages of aerosols and, frequently, traces of nitrogen, fluorine and iron. The analysis method, in combination with cascade impactor sampling, can be a powerful tool for characterization of aerosols. The uranium aerosol source term for risk assessment in nuclear fuel fabrication appears to be highly complex. - Highlights: • Cascade impactor sampling with SEM/EDX analyses of uranium aerosols • First characterization of uranium aerosols in AUC route nuclear fuel fabrication • Uranium complexes/aerosols with novel morphology descriptions • Variable uranium concentrations in aerosols