In this study, titanate nanotubes with a layered structure were investigated for the uptake of radioactive uranium ions for the first time. The nanotubes have been successfully prepared with a reaction of Ti metal nanopowders and NaOH mixed solution by a novel and effective ultrasonic-assisted hydrothermal method. As the absorbent of radioactive ions, they have the ability to selectively adsorb radioactive U ions from water via ion exchange process and subsequently immobilize these ions in the nanotube sorbents without the need of further treatment after absorption. Sorption induces considerable deformation of the layer structures, resulting in the structures changing from the nanotubes to sheets and having the ability of permanent entrapment of the radioactive cations in these as-grown sheets. Our results have proved that titanate nanotubes can be used as a promising absorbent for the removal of nuclear leaking water at the first time.