Patent Number: 
Section: claims

1. A method of transferring a canister of spent nuclear fuel comprising:placing an empty receiving cask having a height on a support capable of vertical movement;lowering the support into a below grade cavity so that a portion of the receiving cask's height is below grade level;positioning a transfer cask containing a canister of spent nuclear fuel above the receiving cask; andlowering the canister of spent nuclear fuel from the transfer cask into the receiving cask. 2. The method of claim 1 wherein the support comprises a plurality of guide rods and wherein the support moves along the plurality of vertical guide rods, the vertical guide rods having a top and a bottom, the vertical guide rods being secured at the top so that any loading from the support results in the vertical guide rods being in tension. 3. The method of claim 1 further comprising the step of providing a setdown structure positioned at a bottom of the cavity, and wherein the step of lowering the empty receiving cask further comprises lowering the support until the support contacts the setdown structure so that any load being borne by the support is supported by the setdown structure. 4. The method of claim 1 wherein at least two jacks are used to lower the support. 5. The method of claim 1 wherein the at least two lifting jacks are coupled so as to keep the support approximately level during vertical movement. 6. The method of claim 5 wherein the jacks are outside the cavity and are accessible from grade level. 7. The method of claim 1 wherein the support has a fully lowered position and a fully raised position. 8. The method of claim 7 wherein when the support is in the fully raised position the support is below grade level. 9. The method of claim 7 wherein when the support is in the fully lowered position, at least a major portion of the receiving cask's height is below grade level. 10. The method of claim 1 wherein the support is a platform having a center and a top surface, the support having a hole near the center and a plurality of cask positioning plates positioned on the top surface. 11. The method of claim 1 wherein the step of lowering the empty receiving cask comprises lowering the empty receiving cask into the cavity until at least a major portion of the receiving cask's height is below grade. 12. The method of claim 11 wherein the empty receiving cask is lowered into the cavity until about 30 inches of the receiving cask is above grade level. 13. The method of claim 1 wherein a shell is provided to form walls of the cavity. 14. The method of claim 13 wherein the shell has a horizontal cross section that is of a size that prohibits the receiving cask from tipping over. 15. The method of claim 13 further comprising the step of inserting one or more lateral restraints between the shell and the receiving cask once the receiving cask is lowered.