Shipping and storage container for spent nuclear fuel

Abstract

A shipping and transport cask for spent nuclear fuel elements. The cask includes a cylindrical cask body having an outer shell and a concentric inner tube. Four quadrant baskets are mounted within the inner tube. Each quadrant basket includes radial and peripheral walls of high thermal conductivity material. A plurality of fuel element-receiving modules and an inner quadrant heat conducting member are mounted within the quadrant baskets. The peripheral walls of the quadrant baskets are held firmly against the inner wall of the body by shims inserted between the radial walls of adjacent quadrant baskets. During assembly, the quadrant baskets are initially forced outwardly against the inner wall by means of expandable spreaders. The cask also includes removable trunnions and primary and secondary external fluid chambers filled with a neutron-attenuating fluid. A siphon tube interconnects the chambers so that the primary chamber which surrounds the major portion of the cask remains filled despite changes in temperature of the fluid.

Dependencies are inferred from the claim text.