Patent Number: 055679528
Section: claims

1. In a container for transport and storage of highly radioactive material, the container being made of thick metal and comprising (i) a tube having an internal wall, and (ii) a base having a lateral wall, said base being non-removably sealed to one end of the tube, and said internal wall and lateral wall forming a right cylinder with a circular cross section in contact with each other, a means for fixing the base of the container, said means comprising:  a) a thick metal tube having first and second ends and an internal wall;  b) a thick metal base permanently sealing the first end of the tube, said base including an external surface, an internal surface and a lateral wall forming together with said internal wall a right cylinder of circular cross section in contact with each other, said lateral wall being disposed entirely inside the tube;  c) a shoulder portion on said internal wall at said first end;  d) a corresponding shoulder portion on said lateral wall, constructed and arranged for engaging the shoulder portion on said internal wall;  e) a first weld seam between said external surface and the tube; and  f) a second weld seam between said internal surface and the tube,  said tube and said base being in shrink-fit relationship at said first end.  a) forming a shoulder on the internal wall at the first end of the tube;  b) forming a corresponding shoulder on the lateral wall of the base, constructed and arranged for engaging the shoulder on the internal wall;  c) shrink fitting the base and the tube with the corresponding shoulders engaged and with the lateral wall entirely inside the tube;  d) forming a first continuous weld seam between the external surface and the internal wall; and  e) forming a second continuous weld seam between the internal surface and the internal wall. 2. A means according to claim 1, wherein the external surface is flush with an end face of the tube. 3. A means according to claim 1, wherein the external surface is recessed in an end face of the tube. 4. A means according to claim 1, wherein the internal wall includes a countersink to hold the base in place. 5. A means according to claim 1, wherein the metal is selected from the group consisting of steels, copper, copper alloys, and bronzes. 6. A means according to claim 1, wherein handling lugs are fixed to a solid external wall of the tube near the base. 7. A container for transport and storage of highly radioactive material comprising: 8. A container according to claim 7, wherein said external surface is flush with said first end of the tube. 9. A container according to claim 7, wherein said external surface is recessed in said first end of the tube. 10. A container according to claim 7, which is helium tight. 11. A method for permanently joining a thick metal tube having an internal wall and first and second ends to a base having a lateral wall and external and internal surfaces, to form a container for transport and storage of highly radioactive materials, comprising the steps of: