Selective Partitioning of Ruthenium from Nitric Acid Media

ABSTRACT

Ruthenium removal from PUREX raffinate solutions is imperative for the application of some advanced actinide partitioning technologies, particularly partitioning of hexavalent americium. Ruthenium interferes with the oxidation of americium and suppresses its extraction. Selective extraction of ruthenium from these solutions is complicated by the existence of multiple ruthenium species in nitric acid. In this work, ruthenium was selectively extracted from nitric acid media through oxidation to ruthenium tetroxide and absorption into polymer beads. Extraction of ruthenium tetroxide into a variety of organic solvents was also explored. The use of UV-Visible spectroscopy to quantify extraction of ruthenium tetroxide was demonstrated. This method for extraction of ruthenium from nitric acid was applied to PUREX raffinate simulant solution and was found to simultaneously remove ruthenium (through oxidation and absorption) and zirconium (through precipitation). This method not only removes ruthenium and zirconium from solution, but also separates ruthenium and zirconium from each other.

KEYWORDS:

• Americium
• fuel cycle
• oxidation
• partitioning
• ruthenium
• solvent extraction

Funding

BJM acknowledges support from the U.S. Department of Energy, Assistant Secretary for Nuclear Energy under the Fuel Cycle Research and Development Sigma Team for Advanced Actinide Recycle (STAAR) program; DOE Idaho Operations Office Contract DE-AC07-05ID14517.

Additional information

Funding

BJM acknowledges support from the U.S. Department of Energy, Assistant Secretary for Nuclear Energy under the Fuel Cycle Research and Development Sigma Team for Advanced Actinide Recycle (STAAR) program; DOE Idaho Operations Office Contract DE-AC07-05ID14517.