Pyrochemical treatment of spent nitride fuels for MA transmutation

Abstract

Nitride fuels have several advantages including high thermal conductivity and high metal density (like metallic fuels) and high melting point and isotropic crystal structure (like oxide fuels). Since the late 1990s, the partitioning and transmutation of minor actinides (MA) has been studied to decrease the long-term radio-toxicity of high-level waste and to mitigate the burden of final disposal. Japan Atomic Energy Agency (JAEA) has proposed a dedicated transmutation cycle using an accelerator-driven system (ADS) with nitride fuels containing MA. The nitride fuel cycle we have developed includes a pyrochemical process. Our focus is on the electrolysis of nitride fuels and their refabrication from the recovered actinides; other processes are similar to the technology for metal fuel treatment and have been studied elsewhere. Here, we summarize our activity on the development of the pyrochemical treatment of spent nitride fuels.