Systematic radiochemical separation for the determination of ~(99)Tc, ~(90)Sr, ~(94)Nb, ~(55)Fe and ~(59,63)Ni in low and intermediate radioactive waste samples

摘要

A simple and rapid separation procedure was systemized for the determination of ~(99)Tc, ~(90)Sr, ~(94)Nb, ~(55)Fe and ~(59,63)Ni in low and intermediate level radioactive wastes. The integrated procedure involves precipitation, anion exchange and extraction chromatography for the separation and purification of individual radionuclide from sample matrix elements and from other radionuclides. After separating Re (as a surrogate of ~(99)Tc) on an anion change resin column, Sr, Nb, Fe and Ni were sequentially separated as follows; Sr was separated as Sr (Ca-oxalate) co-precipitates from Nb, Fe and Ni followed by purification using Sr-Spec extraction chromatographic resin. Nb was separated from Fe and Ni by anion exchange chromatography. Fe was separated from Ni by anion exchange chromatography. Ni was separated as Ni-dimethylglyoxime precipitates after the removal of ~(134,137)Cs and ~(110m)Ag by Cs-phosphotungstate and AgCl precipitation, respectively. Finally, the radionuclide sources were prepared by precipitation for their radioactivity measurements. The reliability of the procedure was evaluated by measuring the recovery of chemical carriers added to a synthetic radioactive waste solution.