Patent Number: 
Section: claims

1. A radiation-shielding assembly for holding a container of radioactive material, the assembly comprising:a body including a radiation shielding material and having a cavity defined therein;a spacer at least partially disposed in the cavity; anda base releasably connected to the body, the base having a spacer stowage receptacle separate from the cavity and defined within the base to accommodate the spacer when the spacer is removed from the cavity when the base is connected to the body. 2. The assembly of claim 1, wherein the base is adapted to releasably secure the spacer in the stowage receptacle. 3. The assembly of claim 1, wherein the base is constructed of a relatively lighter-weight material, and the body is constructed of a relatively heavier-weight material. 4. The assembly of claim 3, wherein the base is constructed of plastic. 5. The assembly of claim 1 further comprising a container of radioactive material disposed in the cavity, the container being in contact with the spacer. 6. A method of using a radiation-shielding assembly, the method comprising:placing a spacer in a cavity of a radiation-shielding assembly;disposing a first container in the cavity while the spacer is in the cavity;removing the spacer and the first container from the cavity; andstowing the spacer in a receptacle defined in the assembly when the cavity is closed, wherein the receptacle is separate from the cavity. 7. The method of claim 6, wherein the stowing step comprises releasably securing the spacer in the receptacle. 8. The method of claim 6, further comprising:disposing a second container in the cavity after the removing, wherein the first container is of a first height, the second container is of a second height, and the first height is less than the second height. 9. The method of claim 6, disposing a second container in the cavity after the removing, wherein a mouth of the first container is located at a defined position relative to the radiation-shielding assembly after the disposing of the first container and prior to the removing of the first container, and a mouth of the second container is located at substantially the same defined position relative to the radiation-shielding assembly after the disposing of the second container.