Simple Determination of 90Sr in Highly Radioactive Liquid Waste by Alkaline Precipitation Separation/Liquid Scintillation Counting Technique

An analytical Method with a liquid scintillation counting technique for the determination of Sr-90 in the presence of other elements was developed by deriving a calculation formula to remove their influences. The analysis of Sr-90 has been performed using the radioactive equilibrium of a generation process of Y-90 with Sr-90 separated from a sample. In this study, a new disintegration calculating formula that enable us to remove the influences by the coexistence nuclides to analyze Sr-90 in highly radioactive liquid wastes of spent-fuel reprocessing plants was derived, and the formula was validated by experimental approaches. It was found that Sr-90 could be analyzed without any influences when a sample contained nuclides that had a long half life, and the radioactive equilibrium was small enough compared to the generation of Y-90 The relative standard deviation of the analysis by the proposed method was equal to, or less than, 3%.