Estimation of 90Sr in reprocessing streams using pre-packed extraction chromatographic column of 4,4'(5')-bis(tert-butylcyclohexano)-18-crown-6 impregnated on amberlite XAD-7

This paper describes a method for the estimation of 90Sr in various PUREX and THOREX process streams. Radiostrontium present in the sample is loaded on an extraction chromatographic column containing 4,4’(5’)-bis(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) in 1-octanol impregnated on amberlite XAD-7 after diluting it appropriately in about 3.0 M HNO3. The column is then washed using 3 M HNO3 to remove the impurities completely and finally 90Sr is eluted in 5 mL of water and subjected to beta counting without time delay. Recovery of 90Sr separation is studied in presence of varying quantity of uranium and thorium in the sample. The method is used to estimate 90Sr in actual process samples containing 90Sr activity in wide range of activity varying from Bq/mL to Ci/L. The results are compared with those obtained by conventional radiochemical precipitation method and found to agree within ±5 %.