Patent Number: 
Section: claims

1. A transfer cask system that implements passive cooling, the transfer cask system comprising:a first cylindrical container having a first side wall that defines a first interior channel extending from a first top to a first closed bottom, the first interior channel containing spent nuclear fuel;a second cylindrical container having a second side wall that defines a second interior channel extending form a second top to a second bottom end, the second interior channel containing the first cylindrical container, the second side wall being spaced from the first side wall to define an annular air passage, the second cylindrical container having air inlets near the second bottom end and an opening at the second top that permit air to flow from the air inlets, through the annular air passage, and to the opening to thereby remove heat by convection from the first cylindrical container; anda transfer door situated at the second bottom end of the second cylindrical container, the transfer door being configured to open and close, and the transfer door comprising one or more support rails configured to support the first cylindrical container resting on the one or more support rails. 2. The transfer cask system of claim 1, wherein the second cylindrical container comprises a transfer cask, the first cylindrical container comprises a spent nuclear fuel container, and the transfer cask is configured to transfer the spent nuclear fuel container from wet storage to dry storage. 3. The transfer cask system of claim 1, further comprising a plurality of spacing components protruding from the second side wall into the second interior channel, wherein the spacing components generate a gap between the second side wall and the first side wall. 4. The transfer cask system of claim 3, wherein the spacing components extend from about the second bottom end to about the second top. 5. The transfer cask system of claim 1, further comprising a liquid neutron shield situated within the second side wall of the second cylindrical container. 6. The transfer cask system of claim 5, wherein the liquid neutron shield is designed to absorb heat emitted from the first cylindrical container. 7. The transfer cask system of claim 5, wherein the liquid neutron shield is designed to shield radiation generated within the first cylindrical container. 8. The transfer cask of claim 1, wherein individual ones of the air inlets extend from an exterior surface of the second cylindrical container to an interior surface of the second cylindrical container. 9. The transfer cask system of claim 1, wherein the second cylindrical container comprises an inlet ring disposed near the second bottom end of the second cylindrical container, and wherein the inlet ring comprises the air inlets such that the air inlets extend from an exterior surface of the inlet ring to an interior surface of the inlet ring. 10. The transfer cask system of claim 1, wherein the first cylindrical container is removably disposed within the second cylindrical container. 11. The transfer cask system of claim 1, further comprising a neutron shield situated at an exterior of the second side wall of the second cylindrical container. 12. A transfer cask system that implements passive cooling, comprising:a first elongated cylindrical container having a first annular side wall that defines a first interior extending from a first top to a first closed bottom, the first interior containing spent nuclear fuel;a second elongated cylindrical container having a second annular side wall that defines a second interior extending from a second top to a second bottom end, the second interior containing the first elongated cylindrical container, the second annular side wall being spaced from the first annular side wall to define an elongated cylindrical annular air passage, and the second elongated cylindrical container having air inlets near the second bottom end and an opening near the second top that permit air to flow from the air inlets, through the elongated cylindrical annular air passage, and to the opening to thereby remove heat by convection from the first elongated cylindrical container;an annular neutron shield associated with the second annular side wall, the annular neutron shield designed to absorb heat produced by the first elongated cylindrical container; anda transfer door positioned at the second bottom end of the second elongated cylindrical container, the transfer door being configured to open and close, and the transfer door comprising one or more support rails configured to support the first elongated cylindrical container resting on top of the one or more support rails. 13. The transfer cask system of claim 12, wherein the annular neutron shield is a liquid neutron shield. 14. The transfer cask system of claim 12, wherein individual ones of the air inlets extend from an exterior surface of the second elongated cylindrical container to an interior surface of the second elongated cylindrical container. 15. The transfer cask system of claim 12, wherein the second elongated cylindrical container comprises an inlet ring disposed near the second bottom end of the second elongated cylindrical container, and wherein the inlet ring forms the air inlets such that the air inlets extend from an exterior surface of the inlet ring to an interior surface of the inlet ring. 16. The transfer cask system of claim 12, wherein the second elongated cylindrical container comprises a transfer cask and the first elongated cylindrical container comprises a spent nuclear fuel container, and the transfer cask is configured to transfer the spent nuclear fuel container from wet storage to dry storage. 17. The transfer cask system of claim 9, wherein the transfer door is coupled to the inlet ring, and the inlet ring further comprises positioning slots configured to engage with the one or more support rails. 18. The transfer cask system of claim 15, wherein the transfer door is coupled to the inlet ring, and the inlet ring further comprises positioning slots configured to engage with the one or more support rails. 19. The transfer cask system of claim 1, wherein the second cylindrical container comprises one or more lifting components extending outwardly from an upper portion of an exterior of the second cylindrical container. 20. The transfer cask system of claim 12, wherein the second elongated cylindrical container comprises one or more lifting components extending outwardly from an upper portion of an exterior of the second elongated cylindrical container.