Patent Number: 
Section: claims

1. A module for storing high level radioactive waste, the module comprising:an outer shell having a hermetically closed bottom end;an inner shell forming a cavity configured for holding a nuclear waste storage canister, the inner shell positioned inside the outer shell so as to form an annular airflow space between the inner shell and the outer shell;a plurality of inlet ducts spaced perimetrically around the outer shell, each inlet duct in fluid communication with ambient atmosphere and the cavity of the inner shell;a removable lid comprising an upper lid part and a lower lid part;the upper lid part positioned atop the inner shell and outer shell to hermetically seal a top of the cavity, the upper lid part including an outlet passageway in fluid communication with ambient atmosphere;the lower lid part extending downwards from the upper lid part into the cavity of the inner shell, the lower lid part having a diameter less than the inner shell defining an annular airflow opening therebetween in fluid communication with the cavity and the outlet passageway of the upper lid part;wherein an air discharge flow pathway is formed from the cavity through the annular airflow opening and outlet passageway of the lid to ambient atmosphere for expelling air heated in the cavity by the storage canister. 2. The module of claim 1, wherein the upper lid part has a diameter larger than a diameter of the outer shell. 3. The module of claim 1, wherein the outlet passageway of the upper lid includes a central aperture in fluid communication with the annular airflow opening via a radially extending outlet passageways formed between the upper and lower lid parts. 4. The module of claim 3, wherein the upper lid part has an annular shape that defines the central aperture and the lower lid part has a disk shape. 5. The module of claim 4, wherein the upper and lower lid parts each comprise an outer shell filled with concrete. 6. The module of claim 3, further comprising a vertical outlet duct extending upwards from a top surface of the upper lid part, the outlet duct fluidly coupling the outlet passageway of the upper lid part to ambient atmosphere. 7. The module of claim 6, wherein the inlet ducts are vertically oriented and the outlet duct has a height greater than a height of each of the inlet ducts. 8. The module of claim 7, wherein the inlet ducts and outlet ducts are cylindrical in shape. 9. The module of claim 6, wherein the outlet duct comprises an outlet wall covered by a duct cover, the outlet wall including peripheral perforations arranged to laterally discharge air from the outlet duct to ambient atmosphere. 10. The module of claim 1, further comprising a plurality of dividers extending from a top of the inner shell to a bottom of the inner shell, the divider creating a plurality of vertical inlet passageways through the annular airflow space, each inlet passageway fluidly connecting to a bottom portion of the cavity. 11. The module of claim 1, wherein each divider includes an extension portion extending through the inner shell into the cavity, the extension portion configured as a guide rib for engaging and centering a canister disposed within the cavity. 12. The module of claim 1, wherein there is no clear line of sight through the lid from the cavity of the inner shell to ambient atmosphere. 13. The module of claim 1, wherein the cavity has a horizontal cross-section that accommodates no more than one canister. 14. The module of claim 13, further comprising:a bottom plenum between a bottom of the canister and a floor of the cavity;a top plenum between a bottom of the lid and a top of the canister; anda clearance existing between an outer side wall of the canister and the inner shell that connects the bottom plenum to the top plenum. 15. A module for storing high level radioactive waste, the module comprising:an outer shell having a hermetically closed bottom end;an inner shell forming a cavity having a horizontal cross-section that accommodates no more than a single nuclear waste storage canister, the inner shell positioned inside the outer shell so as to form an annular air inlet space between the inner shell and the outer shell;a nuclear waste storage canister positioned in the cavity and containing nuclear waste operable to heat air in the air inlet space;a plurality of inlet ducts spaced perimetrically around a top of the outer shell, each inlet duct in fluid communication with ambient atmosphere and the cavity of the inner shell via the annular air inlet space; anda removable lid comprising an upper lid part and a lower lid part having a smaller diameter than the upper lid part;the upper lid part positioned atop the inner shell and outer shell to hermetically seal a top of the cavity, the upper lid part including an air outlet passageway in fluid communication with ambient atmosphere;the lower lid part extending downwards from the upper lid part into the cavity of the inner shell, the lower lid part having a diameter less than the inner shell defining an annular air outlet plenum therebetween in fluid communication with the cavity and the outlet passageway of the upper lid part;wherein air heated by the nuclear waste in the cavity flows into the annular air outlet plenum and through the outlet passageway in the upper lid part to ambient atmosphere. 16. The module of claim 15, wherein the upper lid part has a diameter larger than a diameter of the outer shell. 17. The module of claim 16, wherein the air outlet passageway of the upper lid includes a central aperture in fluid communication with the annular airflow opening via a radially extending outlet passageways formed between the upper and lower lid parts. 18. The module of claim 17, wherein the upper lid part has an annular shape that defines the central aperture and the lower lid part has a disk shape. 19. The module of claim 18, further comprising a vertical outlet duct extending upwards from a top surface of the upper lid part, the outlet duct fluidly coupling the outlet passageway of the upper lid part to ambient atmosphere and having a height greater than a height of the air inlet ducts. 20. A module for storing high level radioactive waste, the module comprising:an outer shell having a hermetically closed bottom end;an inner shell forming a cavity having a horizontal cross-section that accommodates no more than a single canister holding nuclear waste, the inner shell positioned inside the outer shell so as to form an annular air inlet space between the inner shell and the outer shell, the annular air inlet space in fluid communication with the cavity;a nuclear waste storage canister positioned in the cavity and containing nuclear waste generating heat;an upper flange extending radially outwards from an upper portion of the outer shell;a plurality of inlet ducts extending upwards from the flange and spaced perimetrically around the outer shell, each inlet duct fluidly coupled to ambient atmosphere and the annular air inlet space; anda removable lid comprising an upper lid part and a lower lid part;the upper lid part positioned atop the inner shell and outer shell to hermetically seal a top of the cavity, the upper lid part including an air outlet passageway in fluid communication with ambient atmosphere;the lower lid part extending downwards from the upper lid part into the cavity of the inner shell, the lower lid part having a diameter less than the inner shell defining an annular air outlet plenum therebetween in fluid communication with the cavity and the outlet passageway of the upper lid part;wherein air heated by the nuclear waste in the cavity flows upwards into the annular air outlet plenum and through the outlet passageway in the upper lid part to ambient atmosphere.