To separate short-lived nuclide 89Rb from fission products

the separation could be started from their parent nuclides(Kr).An established frozen cold trap was rebuilt to separate inert gas Kr-Xe nuclides in two steps.The theory is based on that different gases have different saturated vapor tensions.With isotopic exchanging technology

the setup has been applied successfully in the separation of 89Rb from complicated fission products.Decontamination factors of main γ-emitters are higher than 1×104.