Speciation of uranium particles using -X-ray absorption near edge structure spectra

Yomogida, Takumi   ; Ouchi, Kazuki  ; Kitatsuji, Yoshihiro  ; Takahashi, Yoshio*

During the decommissioning of the Fukushima Daiichi Nuclear Power Plant, there is concern about the release of fine fuel debris containing nuclear fuel materials into the environment. Solubility of uranium in water differs greatly depending on the chemical species. To estimate the migration behavior of uranium in the environment, it is necessary to understand the chemical species of uranium particles. In this study, we analyzed uranium particles using microbeam X-ray absorption spectroscopy. Uranium particles with a diameter of about 3 m were detected by X-ray fluorescence mapping analysis using a focused X-ray microbeam at about 500 nm. The X-ray absorption near edge structure spectra of the detected particles showed good signal-to-noise ratio and consistent spectra with the UO standard. It is suggested that the proposed method was able to correctly identify the species of UO particles with a diameter of 3 m.