Patent Number: 
Section: claims

1. A nuclear fuel storage cask comprising:an outer shell having a length extending from a first end to a second end of the outer shell positioned opposite the first end, the outer shell defining:an inner cavity circumscribed by the outer shell;an outer perimeter extending around the outer shell;an inner perimeter positioned inward from the outer perimeter and positioned between the outer perimeter and the inner cavity; anda cooling circuit extending along the length of the outer shell, the cooling circuit comprising an inner passage, and an outer passage positioned outward of and in fluid communication with the inner passage;a coolant positioned within the cooling circuit, wherein the coolant is configured to move through the inner passage, absorbing heat from the inner cavity of the outer shell, and the coolant is configured to move through the outer passage, dissipating heat through the outer perimeter of the outer shell; anda lid coupled to the outer shell, wherein the lid covers the inner cavity of the outer shell and the lid comprises a lid cooling circuit, the lid cooling circuit comprising a vapor passage and a lid outer passage distinct from one another, the lid outer passage positioned outward of the vapor passage, and a lid coolant positioned within the lid cooling circuit, wherein the lid coolant remains in the lid cooling circuit and circulates between the vapor passage and the lid outer passage. 2. The nuclear fuel storage cask of claim 1, wherein the inner passage of the cooling circuit is an annular inner passage extending circumferentially around the inner perimeter of the outer shell. 3. The nuclear fuel storage cask of claim 1, wherein the outer passage of the cooling circuit is an annular outer passage extending circumferentially around the inner passage of the cooling circuit. 4. The nuclear fuel storage cask of claim 1, further comprising an exit passage in fluid communication with the inner passage and the outer passage, wherein the exit passage is positioned at the first end of the outer shell and extends circumferentially around the outer shell. 5. The nuclear fuel storage cask of claim 1, further comprising an exit passage radially extending between the inner passage and the outer passage, wherein the exit passage extends radially along the length of the outer shell. 6. The nuclear fuel storage cask of claim 1, further comprising a return passage in fluid communication with the inner passage and the outer passage, wherein the return passage is positioned at the second end of the outer shell and extends circumferentially around the outer shell. 7. The nuclear fuel storage cask of claim 1, further comprising a return passage radially extending between the inner passage and the outer passage, wherein the return passage extends radially along the length of the outer shell. 8. The nuclear fuel storage cask of claim 1, wherein the lid further comprises a lid exit passage. 9. The nuclear fuel storage cask of claim 8, wherein the lid outer passage and the lid exit passage comprise a porous material along the passages. 10. A nuclear fuel storage cask comprising:an outer shell having a length extending from a first end to a second end of the outer shell positioned opposite the first end, the outer shell defining:an inner cavity circumscribed by the outer shell;an outer perimeter extending around the outer shell;an inner perimeter positioned inward from the outer perimeter and positioned between the outer perimeter and the inner cavity; anda cooling circuit extending along the length of the outer shell, the cooling circuit comprising an inner passage, and an outer passage positioned outward of and in fluid communication with the inner passage;a coolant positioned within the cooling circuit, wherein the coolant is configured to move through the inner passage, absorbing heat from the inner cavity of the outer shell, and the coolant is configured to move through the outer passage, dissipating heat through the outer perimeter of the outer shell; anda lid coupled to the outer shell, wherein the lid covers the inner cavity of the outer shell and comprises a heat pipe lid cooling circuit contained entirely within the lid, the cooling circuit comprising a central vapor passage surrounded by a wick and a lid coolant circulating between the vapor passage and wick, wherein the lid further comprises a lid coolant positioned within the lid cooling circuit.