Patent Number: 041773861
Section: claims

1. A storage rack for spent nuclear fuel assemblies for immersion in water, said rack comprising a plurality of identical storage cells disposed adjacent each other in a regular array with adjacent cells connected together, cap members disposed on alternate cells and adapted to guide fuel assemblies into adjacent cells whereby the rack initially contains fuel assemblies in at least half of the storage cells, the remaining cells being filled with water, and at least some of said cap members being removable to permit fuel assemblies to be placed in additional cells in a final pattern determined by the actual level of reactivity of said fuel assemblies such that criticality is prevented. 2. A storage rack as defined in claim 1 in which said storage cells include a neutron-absorbing material. 3. A storage rack as defined in claim 1 in which said storage cells are made of stainless steel. 4. A storage rack as defined in claim 1 in which certain of said cap members are permanently attached to the cells, said permanently attached cap members being in positions in the array of cells which determine said final pattern. 5. A storage rack as defined in claim 1 in which the storage cells are of square cross section and aligned with each other to form a checkerboard array. 6. A storage rack as defined in claim 5 in which cap members are initially disposed on alternate storage cells in each row of cells, the cap members in adjacent rows being staggered with respect to each other. 7. A storage rack as defined in claim 6 in which certain of said cap members are permanently attached to the cells, said permanently attached cap members being on cells which define said final pattern.