Group hexavalent actinide separation from lanthanides using sodium bismuthate chromatography.

Area of Science:

• Nuclear Chemistry
• Radiochemistry
• Materials Science

Background:

• Advanced nuclear fuel reprocessing faces challenges in separating actinides (An) from lanthanides (Ln) due to complex radiochemical processes.
• The hexavalent oxidation state of actinides (Uranium to Americium) offers a potential route for selective group separation from trivalent lanthanides and Curium.
• Existing methods require intricate engineering and separations, limiting efficiency in nuclear waste management.

Purpose of the Study:

• To expand the application of sodium bismuthate (NaBiO3) chromatography for actinide/lanthanide separation.
• To characterize the adsorption, kinetic, and elution behavior of Uranium (U), Plutonium (Pu), and Europium (Eu) using NaBiO3.
• To evaluate the potential of NaBiO3-based separations in nuclear reprocessing, particularly after TRUEX processes.

Main Methods:

• Utilized column chromatography with sodium bismuthate (NaBiO3) as a solid oxidant and ion exchanger.
• Investigated the oxidation and separation of actinides (U, Pu) from lanthanides (Eu) in dilute nitric acid solutions.
• Characterized adsorption, kinetic, and elution behaviors of target elements and key fission products.

Main Results:

• Achieved quantitative oxidation and separation of actinides from lanthanides.
• Observed high separation factors (over 200) with rapid kinetics for U, Pu, and Am from Eu and Cm.
• Demonstrated complete actinide/lanthanide separation in under an hour.
• Characterized the behavior of key fission products, indicating compatibility with existing reprocessing streams.

Conclusions:

• Sodium bismuthate chromatography provides an effective and rapid method for separating actinides from lanthanides.
• This technique shows significant potential for improving advanced nuclear fuel reprocessing strategies.
• NaBiO3-based separation is a promising advancement for nuclear waste management and reprocessing applications.