Separation and quantification of 90Sr from ion-exchange resin radioactive waste: methods and techniques of analysis

Abstract

Abstract Four methods for 90Sr separation from spent ion-exchange resin samples were carried out, offering a useful methodology to achieve interferences free 90Sr fractions. The four methods consist in resin sample decomposition, pre-treatment and selective separation of 90Sr by using: (a) a single chromatographic extraction process, (b) double chromatographic extraction, (c) a single chromatographic extraction process followed in sequence by two precipitations, and (d) ion-exchange chromatography, followed by extraction chromatography and precipitation. Mineralization by microwave acid digestion and the four 90Sr separation methods thoroughly presented are available. Data processing methods (adjustable modified efficiency tracing – a new improved approach for the efficiency tracing LSC technique, non-linear regression and α-β discrimination) to obtain the activities values of α, β-γ, pure β emitters and the evaluation of chemical recovery yield of strontium were presented. A discussion about activity assessment in 90Sr purified fractions, providing a convincing argument to support the accuracy of the 90Sr separation methods, is also offered.