Separation of Actinides and Fission Products Using Titanium-Based Materials

Separation of minor actinides such as americium and curium from lanthanides and other fission products is important for the development of efficient nuclear fuel reprocessing methods. This article describes findings from initial investigations into the use of titanium-based materials for the separation of actinides including americium, plutonium, neptunium, and uranium from fission products including lanthanides, strontium, and cesium. Two types of materials were studied; the first was sodium titanates (ST) that have a layered structure and the second was titanosilicates that have a 3-dimensional tunnel structure. Testing indicated that the layered sodium titanates and tunnel-structured titanosilicate materials exhibit a strong affinity for Am, lanthanides, Sr, and Cs at pH 3 and a significantly reduced affinity for Am and the lanthanides at a higher acid concentration (pH 1). Testing also indicated that the ST material exhibited high affinity for actinides in a pH 3 solution. The addition of complexing agents significantly decreased the sorption of Am and lanthanides.