Separation and purification of 131I from neutron irradiated tellurium dioxide targets by wet-distillation method

Separation and purification of carrier-free 131I by the wet-distillation method from thermal neutron irradiated tellurium dioxide targets along with their Al wrappers in 8N H2SO4, HNO3 and HCl acid solutions containing H2O2 and refluxing for 3 h is investigated. The distilled off 131I is absorbed in a mixture solution of NaOH + Na2S2O3 after passing through 0.5N H2SO4 acid filter. The corresponding 131I separation factor, recovery yield and percentage trapped in the acid filter and radionuclidic, radiochemical and chemical purity indices and discussions favour the use of H2SO4 acid as the distillation medium. The corresponding separation and purification indices of 131I are investigated as a function of chemical composition of the distillation medium (e.g., concentration of H2SO4, kind and concentration of the oxidant, the sequence of addition of H2SO4/H2O2, chemical impurities and catalyst), chemical composition of the acid filter (e.g., concentration of H2SO4 and additives such as H2O2 and oxalic acid) and radioiodine carrier-gas (e.g., air and nitrogen). By applying the recommended separation and purification procedure, 131I product solution of high separation, recovery and purity indices is obtained.