Patent Number: 042960746
Section: abstract

A method of decladding an assembly comprising an element selected from the group consisting of uranium, thorium and mixtures thereof, clad in stainless steel, zirconium, or an alloy consisting essentially of zirconium and containing minor amounts of nickel, chromium, tin, iron or combinations thereof. In a first step the cladding is scored or perforated to expose the selected element. Thereafter, the assembly is exposed to a hydrogen atmosphere at an elevated temperature for a time sufficient for the hydrogen and selected element to react and form a hydride. The temperature then is further increased to decompose the hydride back to gaseous hydrogen and the selected element. The hydriding-dehydriding preferably are repeated at least two additional times to ensure complete release of any volatile gases present. The formation of the hydride which has substantially greater volume than the selected element ruptures the cladding assembly and the subsequent dehydriding leaves the selected element in a friable granular form whereby it is readily separable from the cladding material by conventional mechanical means such as sieving or the like.