Patent ID: 7215728

Claim:
A basket comprising: a square pipe assembly having a plurality of square pipes assembled in a staggered arrangement, wherein each of the plurality of square pipes comprises: four walls and four corners arranged so as to form a square cross section, the four walls including neutron-absorbing material and having a thickness capable of preventing spent fuel inserted therein from reaching criticality and capable of ensuring a predetermined strength at a time of falling down, wherein a cell for housing a spent fuel aggregate is formed in a space defined by walls of the square pipes; a connecting section formed on each of the four corners, at which diagonally adjacent square pipes are contacted with each other, wherein the connecting section is formed into a terrace shape having a plurality of steps, and the steps of the terrace shape are formed to butt against the steps of adjacent square pipes when the square pipes are assembled in a staggered arrangement; and a square pipe receiver placed between adjacent square pipes located on the outermost circumference of the square pipe assembly.