Patent Number: 054385970
Section: claims

1. A canister for storing and transporting nuclear fuel assemblies, comprising: (a) a basket assembly, including:  (b) an exterior shell, forming an enclosure open at one end, the exterior shell receiving and surrounding the basket assembly, the basket assembly being oriented within the shell, so that the longitudinal axis of each row is substantially parallel to the longitudinal axis of the shell;  (c) a plurality of guide sleeves, corresponding to the number of rows of axially aligned plate apertures, each guide sleeve for receiving a nuclear fuel assembly and having a longitudinal axis generally coincident with a respective corresponding row, each guide sleeve comprising:  (d) a lid, adapted to mate with the open end of the shell, thereby closing the open end of the shell.  (a) a basket assembly, including:  (b) an exterior shell, forming an enclosure open at one end, the exterior shell receiving and surrounding the basket assembly, the basket assembly being oriented within the shell, so that the longitudinal axis of each row is substantially parallel to the longitudinal axis of the shell;  (c) a plurality of guide sleeves, corresponding to the number of rows of axially aligned plate apertures, each guide sleeve for receiving a nuclear fuel assembly and having a longitudinal axis generally coincident with a respective corresponding row, each guide sleeve comprising:  (d) a first lid, adapted to mate with the open end of the shell, thereby closing the open end of the shell, the first lid being used with nuclear fuel assemblies of one length; and  (e) a second lid, adapted to mate with the open end of the shell, thereby closing the open end of the shell, the second lid being used with nuclear fuel assemblies of the other length. 2. The canister of claim 1, wherein the first structural layer comprises a hollow steel jacket inserted into each row of axially aligned apertures. 3. The canister of claim 2, wherein the neutron absorbing layer comprises a borated neutron absorbing material. 4. The canister of claim 3, wherein the second structural layer comprises a steel jacket, at least surrounding the portion of the borated neutron absorbing material exposed between the apertured plates. 5. The canister of claim 1, further comprising a weld sealing the lid to the shell to form an airtight enclosure. 6. The canister of claim 1, further comprising a second retainer connected to at least one of the structural layers for limiting movement of the neutron absorbing layer in a second direction, opposite from the first direction. 7. The canister of claim 1, wherein the first structural layer comprises a four-sided hollow jacket. 8. The canister of claim 7, wherein the neutron absorbing layer comprises at least one separate sheet of a borated neutron absorbing material, placed adjacent at least one side of the four-sided hollow jacket. 9. The canister of claim 1, where the neutron absorbing layer comprises at least one separate, generally rectangular shaped sheet of a borated neutron absorbing material. 10. The canister of claim 1, wherein the neutron absorbing layer is in fluid communication with the environment exterior to the first and second structural layers. 11. A system for storing and transporting nuclear fuel assemblies of two different lengths, comprising; 12. The system for storing and transporting nuclear fuel assemblies of claim 11, wherein the first lid is thinner than the second lid. 13. The system for storing and transporting nuclear fuel assemblies of claim 19, wherein the first lid includes a lead core surrounded by an outer layer of steel.