Patent Number: 
Section: claims

1. A system for transferring spent nuclear fuel comprising: a cask having a horizontal cross-section for receiving the spent nuclear fuel;  a below grade opening adapted for receiving the cask;  a cask support means positioned within the opening, the cask support means capable of vertical movement;  means for vertically moving the cask support means;  wherein the cask support moans is capable of lowering the cask within the opening; and  a shell forming walls of the opening, the shell having a horizontal cross section that is slightly larger than the horizontal cross section of the cask. 2. The system of  claim 1  wherein the shell and the cask are cylindrical. claim 1 3. The system of  claim 1  wherein the means for vertically moving the cask support, means is at least two lifting jacks. claim 1 4. The system of  claim 3  wherein the plurality of lifting jacks are coupled so as to keep the cask support means approximately level during vertical movement. claim 3 5. The system of  claim 3  wherein the number of lifting jacks is three. claim 3 6. The system of  claim 3  wherein the jacks are located outside the opening and are accessible from grade level. claim 3 7. The system of  claim 1  wherein the cask support means has a fully lowered position and a fully raised position. claim 1 8. The system of  claim 7  wherein when the cask support means is in the fully raised position the cask support means is below grade. claim 7 9. The system of  claim 7  wherein when the cask support means is in the fully lowered position and supporting a cask having a height, at least a major portion of the cask""s height is below grade level. claim 7 10. The system of  claim 1  wherein the opening has a bottom, the system further comprising a setdown structure positioned at the bottom of the opening and below the cask support means. claim 1 11. The system of  claim 1  wherein the cask support means is a platform having a center and a top surface. claim 1 12. The system of  claim 1  further including vertical guide rods on which the cask support means can move. claim 1 13. The system of  claim 1  wherein when the cask is positioned in the opening, the horizontal cross section of the shell is substantially concentric with the horizontal cross section of the cask. claim 1 14. The system of  claim 1  wherein when the cask is positioned in the opening, a tight clearance is formed between the shell and the cask. claim 1 15. A system for transferring spent nuclear fuel comprising: a below grade opening for receiving a cask;  a cask support means positioned within the opening, the cask support means capable of vertical movement between a fully lowered position and fully raised position;  means for vertically moving the cask support means;  the cask support means capable of lowering the cask within the opening  wherein when the cask support means is in the fully lowered position and supporting the cask, approximately 30 inches of the cask is above grade level. 16. A system for transferring spent nuclear fuel a below grade opening having a bottom and adapted for receiving a cask;  a cask support means positioned within the opening, the cask support means capable of vertical movements;  means for vertically moving the cask support means;  the cask support means capable of lowering the cask within the opening;  a setdown structure positioned at the bottom of the opening and below the cask support means; and  wherein when the cask support means is in a fully lowered position, the cask support means contacts the setdown structure and the cask support means and any load being borne by the cask support means is supported by the setdown structure. 17. A system for transferring spent nuclear fuel comprising: a below grade opening adapted for receiving a cask;  a platform for supporting the cask, the platform positioned within the opening and capable of vertical movement;  means for vertically moving the platform;  the platform capable of lowering the cask within the opening;  the platform having a center, a top surface a hole near the center, and a plurality of cask positioning plates on the top surface. 18. A system for transferring spent nuclear fuel a below grade opening for receiving a cask;  a cask support means positioned within the opening, the cask support means capable of vertical movement; and  means for vertically moving the cask support means;  vertical guide rods on which the cask support means can move; and  wherein the vertical guide rods have a top and a bottom, the vertical guide rods being secured at the top so that upon loading the cask support means the vertical guide rods are in tension. 19. A system for transferring spent nuclear fuel comprising: a cask for receiving the spent nuclear fuel;  a below grade opening adapted for receiving the cask;  a cask support means positioned within the opening, the cask support means capable of vertical movement between a fully lowered position end fully raised position;  means for vertically moving the cask support means;  the cask support means capable of lowering the cask within the opening;  wherein when the cask support means is in the fully lowered position and supporting the cask, a portion of the cask is above grade level.