Patent Number: 
Section: claims

1. A radioactive contaminant container comprising:a wall that defines a containing space for containing radioactive contaminants and shields at least a portion of radiation irradiated from the radioactive contaminants,wherein the wall has an outer shape of a hexagonal cylinder or a substantially hexagonal cylinder,wherein the wall includes a first protrusion extending along an axial direction of the hexagonal cylinder or the substantially hexagonal cylinder and protruding outward; and a first recess extending along the axial direction and recessed inward, andwherein the first recess can be fitted to the first protrusion formed in the other radioactive contaminant container. 2. The radioactive contaminant container according to claim 1,wherein the wall includes a first surface and a second surface, each extending in a direction intersecting with the axial direction of the hexagonal cylinder or the substantially hexagonal cylinder, and each shape being hexagonal or substantially hexagonal,wherein any one surface of the first surface and the second surface includes a second protrusion protruding outward, and the other surface includes a second recess recessed inward, andwherein the second recess can be fitted to the second protrusion formed in the other radioactive contaminant container. 3. The radioactive contaminant container according to claim 1,wherein the wall includes a metal plate having multiple through-holes. 4. The radioactive contaminant container according to claim 1,wherein a portion of the wall is formed to be attachable to and detachable from the other portion of the wall, or to be openable and closeable in order to contain the radioactive contaminants in the containing space. 5. The radioactive contaminant container according to claim 1,wherein the wall includes a layer containing radiation shielding materials having at least silicon, strontium, magnesium, europium and dysprosium as essential elements. 6. The radioactive contaminant container according to claim 5,wherein the wall further includes a layer formed of stainless steel. 7. The radioactive contaminant container according to claim 5,wherein the layer containing the radiation shielding materials is a layer in which the radiation shielding materials are added to resin or rubber. 8. The radioactive contaminant container according to claim 1,wherein the wall is formed of stainless steel. 9. The radioactive contaminant container according to claim 1,wherein the radioactive contaminant container contains a reverse osmosis membrane used to purify radioactively contaminated water. 10. A radioactive contaminant container,wherein a containing space for containing radioactive contaminants contains multiple radioactive contaminant containers according to claim 9. 11. The radioactive contaminant container according to claim 1,wherein the first recess is disposed on three surfaces which are not adjacent to each other within six surfaces extending in the axial direction of the hexagonal cylinder or the substantially hexagonal cylinder, andwherein a handle for attaching a wire rope for transportation is disposed in the first recess.