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

Abstract Four methods for 90 Sr separation from spent ion-exchange resin samples were carried out, offering a useful methodology to achieve interferences free 90 Sr fractions. The four methods consist in resin sample decomposition, pre-treatment and selective separation of 90 Sr 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 90 Sr 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 90 Sr purified fractions, providing a convincing argument to support the accuracy of the 90 Sr separation methods, is also offered.