Image Number 8 for United States Patent #4192629.
An underground repository for the storage of radioactive material, particularly spent fuel from nuclear reactors and radioactive wastes produced by reprocessing spent nuclear fuel. The repository comprises a hollow body of solid material for accommodating the radioactive material. The hollow body is surrounded by a shell or barrier of clay. The hollow body and the clay barrier are located in a cavity in rock, the clay filling the space between the hollow body and the inside of the rock cavity.