Conceptual design of a container with drainage system for treating and transporting the radioactive wastes under water during decommissioning of nuclear facilities

•A container for transportation of the radioactive wastes under water.•Capable of selectively draining water.•Storing the radioactive waste in the container body under water. The purpose of this paper is to design an improved container with drainage system for treating and transporting the radioactive wastes under water during decommissioning of nuclear facilities. It is possible to selectively drain water flown into the container body together with the radioactive waste during treatment and transportation of the radioactive waste under water. It is possible to safely lift the radioactive waste container from the water upon completion of the storage of the radioactive waste under water and easily transport the radioactive waste container to a temporary and disposal site.