Analysis of Aqueous and Organic Fission-Product Solutions by Energy-Dispersive X-Ray Fluorescence

摘要

Because of a revival of interest in reprocessing spent nuclear reactor fuel, ORNL is re-evaluating existing data on extractions. Organic degradation products and new organic extractant systems must also be investigated. Analysis of these solutions present several problems for the analytical chemist. Conventional wet chemical techniques usually require aqueous solutions. Organic solutions must be stripped or wet ashed to convert them to an aqueous system. Stripping is not always quantitative, and the high phosphorus content of organic extractants makes wet ashing difficult. Radiolysis degrades many organic solutions. In aqueous solutions, low acid concentrations cause Pu to polymerize and Zr and Mo to form colloids or precipitate; therefore, sample pretreatment becomes necessary. Energy dispersive x-ray fluorescence (XRF) is a multi-element technique, unaffected by chemical states, capable of analyzing both aqueous and organic solutions. Thie technique has been applied to the determination of U, Pu, Th, Mo, Zr and Re in cold flow sheet development. (ERA citation 07:008070)