Routine radiochemical method for the determination of ⁹⁰Sr, ²³⁸Pu, ^239+240Pu, ²⁴¹Am and ²⁴⁴Cm in environmental samples

Summary

Routine analytical procedures have been developed for the reliable simultaneous determination of ⁹⁰Sr, ²³⁸Pu, ^239+240Pu, ²⁴¹Am and ^242-244Cm, Chernobyl derived radioisotopes and fallout after nuclear weapon tests in a wide range of environmental samples: soil (100-200 g), sediments, aerosols, water and vegetation. This procedure has been applied to thousands of soil and sediment samples and hundreds of biological and water samples taken in the exclusive zone of Chernobyl NPP and different regions of Ukraine from 1989 to the present. After the sample has been properly prepared and isotopic tracers added, plutonium, americium and curium are precipitated with calcium oxalate and then lanthanum fluoride. Plutonium is separated from americium and curium by anion-exchange. Americium and curium are separated from rare earths by cation-exchange with gradient elute &agr;-hydroxy-iso-butyric acid. During projects by AQCS IAEA “Evaluation of Methods for ⁹⁰Sr in a Mineral Matrix' and “Proficiency Test for ²³⁹Pu, ²⁴¹Pu and ²⁴¹Am Measurement in a Mineral Matrix' accuracy and precision for ⁹⁰Sr, ²³⁹Pu and ²⁴¹Am by present procedure was evaluated. Advantages, difficulties and limitations of the method are discussed.