Contribution to upgrade of vitrification technology by synchrotron radiation analysis; From Chemical state analysis of waste glass to development of structural analysis to prove soundness

Okamoto, Yoshihiro  ; Nagai, Takayuki  ; Shiwaku, Hideaki   

The vitrified radioactive waste is a multicomponent material containing many kinds of elements. Synchrotron radiation XAFS with element selectivity is suitable for analysis of elements in the waste. From the XAFS analysis, the chemical state and the local structure of each element were clarified. Imaging XAFS technique was used as an analysis based on element distribution in the glass. The imaging XAFS is effective for analysis of elements that are less soluble in the glass like molybdenum and platinum group elements. It was clarified from the simultaneous imaging XAFS analyses of multiple elements that the chemical form of rhodium is strongly dominated by the distribution correlation with ruthenium. We proposed multi - scale structural analyses with wide angle scattering, PDF analysis, small angle scattering in order to evaluate the soundness of the vitrified waste.