Patent Number: 
Section: claims

1. A cylinder for the transport of substantially pure uranium hexafluoride in a conventional overpack, the cylinder comprising a closed steel vessel, the vessel having a cylindrical sidewall and a head closing one end of the vessel, the head being permanently affixed to the sidewall, the head having a valve controlling the flow of matter into and out of the vessel,  a sealing surface connected to the vessel and surrounding the valve,  a cap over the valve, and  fastening means for pressing the cap against the sealing surface to seal a joint between them against the flow of matter from outside the cap to the valve and from the valve to outside the cap. 2. The cylinder of  claim 1  including a disk surrounding the valve and the sealing surface is a surface of the disk. claim 1 3. The cylinder of  claim 1  wherein the fastening means includes a threaded fastener. claim 1 4. The cylinder of  claim 1  wherein the fastening means includes a plurality of threaded fasteners. claim 1 5. The cylinder of  claim 1  wherein the sealing surface is an annular surface and the cap includes an opposed surface proportioned to abut the sealing surface, and further including a resilient seal element disposed between the opposed surface and the sealing surface. claim 1 6. The cylinder of  claim 5  including an endless recess formed in the opposed surface of the cap and surrounding the valve when the opposed surface abuts the sealing surface. claim 5 7. The cylinder of  claim 6  wherein the resilient seal is disposed at least partially within the recess formed in the opposed surface. claim 6 8. The cylinder of  claim 1  including means for testing the integrity of the seal between the cap and the sealing surface when the fastening means presses the cap against the sealing surface. claim 1 9. The cylinder of  claim 8  including a pair of resilient seal elements, one surrounding the other, the resilient seal elements being positioned between the cap and the sealing surface. claim 8 10. The cylinder of  claim 9  wherein the means for testing the integrity of a seal includes a passage connecting an outside surface of the cap with a space between the two resilient seal elements. claim 9 11. The cylinder of  claim 10  wherein the cap includes a working surface proportioned to abut the sealing surface, the working surface having a first endless recess surrounding the valve when the cap is over the valve, a second endless recess surrounding the first endless recess, and resilient seal elements disposed in the recesses. claim 10 12. The cylinder of  claim 11  wherein the resilient seal elements are O-rings. claim 11 13. The cylinder of  claim 1  wherein the vessel includes a chime connected to the head and extending axially away from the head, the chime having a free end defining a plane, the valve sealing surface and cap being surrounded by the chime, and being spaced inward toward the head from the plane. claim 1 14. The cylinder of  claim 13  wherein the cap is spaced inward from the plane toward the head by at least xc2xd in. claim 13 15. The cylinder of  claim 14  including means for testing the integrity of the seal between the cap and the sealing surface when the fastening means presses the cap against the sealing surface. claim 14 16. The cylinder of  claim 15  including a pair of resilient seal elements, one surrounding the other, the resilient seal elements being positioned between the cap and the sealing surface. claim 15 17. The cylinder of  claim 16  wherein the means for testing the integrity of a seal includes a passage connecting an outside surface of the cap with a space between the two resilient seal elements. claim 16 18. The cylinder of  claim 17  wherein the cap includes a working surface proportioned to abut the sealing surface, the working surface having a first endless recess surrounding the valve when the cap is over the valve, a second endless recess surrounding the first endless recess, and resilient seal elements disposed in the recesses. claim 17 19. The cylinder of  claim 18  wherein the resilient seal elements are O-rings. claim 18 20. The cylinder of  claim 13  wherein the cap is spaced inward from the plane toward the head by at least xc2xe in. claim 13 21. The cylinder of  claim 20  including means for testing the integrity of the seal between the cap and the sealing surface when the fastening means presses the cap against the sealing surface. claim 20 22. The cylinder of  claim 21  including a pair of resilient seal elements, one surrounding the other, the resilient seal elements being positioned between the cap and the sealing surface. claim 21 23. The cylinder of  claim 22  wherein the means for testing the integrity of a seal includes a passage connecting an outside surface of the cap with a space between the two resilient seal elements. claim 22 24. The cylinder of  claim 23  wherein the cap includes a working surface proportioned to abut the sealing surface, the working surface having a first endless recess surrounding the valve when the cap is over the valve, a second endless recess surrounding the first endless recess, and resilient seal elements disposed in the recesses. claim 23 25. The cylinder of  claim 24  wherein the resilient seal elements are O-rings. claim 24 26. In a conventional 30B cylinder for the transport of substantially pure uranium hexafluoride which has a cylindrical sidewall, a head closing one end of the cylinder and permanently affixed to the sidewall, and a valve connected to the head for controlling the flow of material into and out of the cylinder, the improvement comprising a removable protective valve cover assembly means for providing an essentially impermeable cover over the valve, and means for testing a seal between the valve cover assembly means and the cylinder. 27. The improvement of  claim 26  wherein the protective valve cover assembly means includes a cap having a flange and a sealing surface connected to the cylinder and surrounding the valve. claim 26 28. The improvement of claim of  27  including a pair of resilient seal elements, one within the other, positioned between the flange and the sealing surface, and the means for testing includes a passage from outside the protective valve cover assembly to a space between the resilient seal elements. 29. A method of shipping substantially pure uranium hexafluoride comprising providing a cylinder having a cylindrical sidewall, a head closing one end of the cylinder and permanently affixed to the sidewall, and a valve connected to the head for controlling the flow of matter into and out of the cylinder and a removable cap over the valve, removing the cap,  filling the cylinder with uranium hexafluoride through the valve,  closing the valve,  placing the cap over the valve to seal the space between the inside of the cap and the valve, and thereafter  testing the integrity of the seal. 30. The method of  claim 29  further including the step of placing the cylinder inside a conventional overpack. claim 29 31. In the combination of an overpack for a conventional 30B cylinder and a conventional 30B cylinder containing substantially pure uranium hexafluoride in the overpack, the cylinder having a cylindrical sidewall, a head closing one end of the cylinder and permanently affixed to the sidewall, and a valve connected to the head, the improvement comprising a removable protective valve cover assembly, means for providing an essentially impermeable cover over the valve, and means for testing a seal between the valve cover assembly means and the cylinder. 32. The improvement of  claim 31  wherein the protective valve cover assembly means includes a cap having a flange and a sealing surface connected to the cylinder and surrounding the valve. claim 31 33. The improvement of claim of  32  including a pair of resilient seal elements, one within the other, positioned between the flange and the sealing surface, and the means for testing includes a passage from outside the protective valve cover assembly to a space between the resilient seal elements. 34. A cylinder for the transport of substantially pure uranium hexafluoride fitting within an envelope having an overall length of 81xc2xd inches plus or minus xc2xd inch and a diameter of 30 inches plus or minus xc2xc inch, the cylinder enclosing a volume of at least 26 cubic feet, the cylinder comprising a closed steel vessel having a cylindrical sidewall, a head closing one end of the cylinder and permanently affixed to the sidewall, and a valve connected to the head for controlling the flow of matter into and out of the vessel, a sealing surface connected to the vessel surrounding the valve, a removable cap over the valve, and fastening means for sealingly mounting the cap to the sealing surface. 35. The cylinder of  claim 34  including chimes within the envelope of the cylinder. claim 34 36. The cylinder of  claim 35  where in the removable cap is completely within the envelope of the cylinder when the cap is mounted to the sealing surface. claim 35 37. The cylinder of  claim 36  including means for testing the rate at which matter can flow between the sealing surface and the cap when the cap is mounted to the sealing surface. claim 36 38. The cylinder of  claim 37  including a pair of resilient sealing elements between the cap and the sealing surface and the means for testing includes a passage having one end between the two resilient sealing elements and another end adapted to be connected to a source of fluid under pressure or vacuum. claim 37 39. The cylinder of  claim 38  disposed within a conventional overpack. claim 38