Separation of Am-Cm from NaNO sub 3 Waste Solutions by in-Canyon-Tank Precipitation as Oxalates

摘要

A process for the purification of Am-Cm residues was developed specifically for application in Savannah River Plant (SRP) canyon tanks. These Am-Cm residues were collected from several campaigns to produce plutonium containing high isotopic concentrations of exp 240 Pu. An initial purification from Al exp 3+ had already been accomplished by a solvent extraction process. The product of this process was contaminated with NaNO sub 3 as a result of entrainment of the solvent extraction NaNO sub 3 scrub solution. To produce an acceptable feed solution for a later pressurized cation exchange chromatography separation and purification step, the bulk of the NaNO sub 3 must be removed. This purification process includes formic acid denitration, adjustment of contaminating cations by evaporation and water dilution, and oxalate precipitation of the actinides and lanthanides. (ERA citation 07:003384)