An adequate response to terrorist event of any magnitude requires the effective coordination of many organizations. A terrorist event involves the release and dispersion of radioactive material among civilian population or over vital area causes a permanent radioactive contamination, which should be removed in decontamination process. Finally, after this procedure, a large amount of radioactive waste water is made, which should be collected and stored in a special nuclear waste stockpile. We present results of experimental work, which was focused on removal of radioactive substances from waste water from decontamination process after using “dirty bomb”. The ion flotation process was used to remove radioisotopes from slightly salty (<1.0⋅10^–3 mol/dm³) aqueous solutions. Multistage ion flotation and fractionation of concentrate from the ion flotation process using appropriate lariat ethers as collectors allowed separation of radioisotopes, which might have a practical usage for the decontamination of radioactive waste aqueous solutions.