Rapid method for the determination of ⁷⁹Se in radioactive concentrates

The method of ⁷⁹Se separation by distillation was optimized. Selenium recovery was evaluated by using an ⁷⁵Se tracer, whose radiation was detected with a HPGe detector at Eγ = 136 keV and 264.8 keV. Different concentrations of HCl were used as the distillation medium. The conditions for the effective distillation of selenium depend on the volume of 18.31 mol•dm^-3 HBr and on the amount of distillate. The recoveries were highest (91 - 92%) when using HCl concentrations of (4 - 6.5) mol•dm^-3. The highest radiochemical recoveries of selenium (83 - 92 %) were attained if the volume of HBr (18.31 mol•dm^-3) was 3-7 cm³. The optimum distillate volume was 35 cm³. The optimum amount of the Se⁴⁺ carrier added to the model samples was 5-15 mg.