Designing and Demonstration of the UREX+ Process Using Spent Nuclear Fuel

As part of the Advanced Fuel Cycle Initiative, Argonne National Laboratory demonstrated the UREX+ process using a 2-cm centrifugal contactor. The UREX+ process consisted of five solvent extraction processes that separated dissolved spent fuel into seven fractions. Following dissolution, uranium and technetium were recovered from the feed in separate product streams. Uranium was recovered in high yield (>99.9%) with a purity that would allow its disposal as nonTRU low-level waste; >99% of the Tc was recovered in high purity. In the next process, which was designed by researchers at INEEL, cesium and strontium were removed from the UREX raffinate. After feed adjustment, plutonium and neptunium were recovered in the NPEX process with high yield and impurity levels making it suitable for use as feed to MOX fuel. The raffinate of the NPEX process was fed to a TRUEX process where the minor actinides and rare-earth elements were recovered. The TRUEX product was fed directly to a Cyanex 301 process where minor actinides were purified from rare-earth elements. (Raffinates from the TRUEX and Cyanex 301 processes could be disposed separately or together.) Results of this demonstration and the AMUSE code used to design it will be discussed.