[en] Object: To carry out a series of processes, in a vessel, of separating, condensing, dewatering and solidifying a solid portion contained in a radioactive liquid waste. Structure: Radioactive liquid is ejected from a nozzle into the rotor and the radioactive liquid is separated into solid and liquid by a turning force of the rotor. The solid matter is adhered to the wall of the rotor and clear water enters a second space through an outlet drilled in the periphery of a hollow cylinder at the upper part of the rotor and is discharged through an outlet disposed in a lower wall of a housing. When the solid matter is somewhat accumulated within the rotor, the rotor is stopped to discharge the liquids remaining in the rotor outside the rotor through an opening in a cylindrical shaft at a lower end of the rotor. Finally, solidifying material such as cement is thrown into the housing through an inlet thereof to fill it into three spaces through a communicating hole until the housing forms one sheet. (Taniai, N.)