Low cost, minimum weight fuel assembly storage cask and method of

Abstract

A low cost, minimum weight cask for the storage of fuel assemblies is disclosed herein, along with a method for the construction thereof. The cask generally comprises a wall assembly for defining a cask interior that is complementary in shape to a rectangular array of radioactive fuel assemblies that is formed from four flat, metallic wall plate members having mutually parallel side edges which are adjoined be welds that penetrate only part way through the thicknesses of the wall plate members. The cask further includes a floor plate attached to the bottom of the wall assembly, and a lid that is detachably connectable to the top of the wall assembly. A basket assembly formed from parallel and uniformly spaced plates of borated aluminum interconnected in 'egg crate' fashion is disposed in the rectangular interior of the cask. To minimize weight, each of the corners of the wall assembly is truncated. Mutually adjacent and adjoined side edges of two different wall plate members include mutually interfitting portions for avoiding the creation of a streaming path for radiation. The use of welds to adjoin the side plate members that penetrate only a fraction of the thickness of these members, in combination with the rectangular shape of the cask and the truncated corners thereof results in a low cost, minimum weight storage cask for fuel assemblies.