A rapid method for determining 90 Sr in leaching solution from cement solidification of low and intermediate level radioactive wastes

A rapid, low cost method for the determination of 90 Sr in leaching solution of cement solidification was developed using triple-to-double coincidence ratio (TDCR) Cerenkov counting of 90 Y. In this method, 90 Y was separated from sample matrix and interfering radionuclides through two co-precipitation steps with hydrous titanium oxide followed by yttrium fluoride (YF 3 ) precipitation. After dissolution of the YF 3 precipitate, 90 Y was measured by TDCR Cerenkov technique. The performance of the method was examined using a series of the samples spiked with various activities of 90 Sr ranging from 1.75 to 32 Bq L −1 , along with the procedural blanks. The mean chemical recovery of Y was 86 ± 8%. The measured 90 Sr agreed well with the expected 90 Sr within an acceptable deviation of ~10%. The minimum detectable concentration was about 0.3 Bq L −1 for 0.2 L sample with a counting time of 5400 s by a Hidex 300 SL TDCR liquid scintillation counter. The overall decontamination coefficients were determined to be >5400 for 60 Co, >5300 for 137 Cs, >14,500 for 40 K and 4500 ± 580 for 210 Pb/ 210 Bi, respectively.