Analysis of simulated glass solidified samples and simulated fuel debris samples using simultaneous microbeam XAFS/XRF/XRD measurements in the same field of view

Tanida, Hajime  ; Okamoto, Yoshihiro  ; Akiyama, Daisuke*; Kirishima, Akira*

A technique was established for analysing the elemental composition, crystalline phase and chemical state. This was achieved by performing XAFS/XRF/XRD measurements within the same field of view using a microbeam focused to approximately 0.001 mm. The samples analysed were molybdate crystals precipitating within the sample, known as the yellow phase. This is problematic in the simulated vitrification process for high-level radioactive liquid waste, and simulated fuel debris samples generated in reactor accidents. In the case of the yellow phase samples, it was confirmed that the chemical state of molybdenum differs from that in the glass phase. In the context of the simulated fuel debris samples, which are characterised by multicomponent and multiphase systems where the composition ratio exhibits local variations on the order of tens of micrometers and does not constitute a homogeneous solid solution, it has been confirmed that the chemical state of uranium within the U-rich phase can be selectively determined.