Design of an integrated system to recycl

A process for recycling spent nuclear fuel cladding, a zirconium alloy (Zircaloy), into a metal powder that may be used for advanced nuclear fuel applications was investigated to determine if it is a viable strategy. The process begins with hydriding the Zircaloy cladding hulls after the spent nuclear fuel has been dissolved from the cladding. The addition of hydrogen atoms to the zirconium matrix stresses the lattice and forms brittle zirconium hydride, which is easily pulverized into a powder. The dehydriding process removes hydrogen by heating the powder in a vacuum, resulting in a zirconium metal powder. The two main objectives of this research are to investigate the dehydriding process and to design, build and demonstrate a specialized piece of equipment to process the zirconium from cladding hulls to metal powder without intermediate handling. The hydriding process (known from literature) took place in a 95% argon - 5% hydrogen atmosphere at 500°C while the dehydriding process conditions were researched with a Thermogravimetric Analyzer (TGA). Data from the TGA showed the dehydriding process requires vacuum conditions (~0.001 bar) and 800°C environment to dehydride the powder effectively.