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Radiochemical Processing Laboratory

Radiochemical Separation - From Basic Science to Industrial Application

Separations Equipment
Centrifugal contactors for continuous counter-current solvent extraction testing (Enlarge image)

Radiochemical separations R&D has transpired in the RPL since the facility first opened in the early 1950s. The significance of the radiochemical separations work conducted in the facility is evidenced by the fact that three long time building residents have received the Glenn T. Seaborg Actinide Separations Award.

Today, RPL researchers are building upon this historical excellence to lead radiochemical separations into the 21st Century. The RPL unique facilities and broad-based staff allow for separations research to span the spectrum from the molecular level up to testing of flowsheets for industrial application.

Basic Separations Science

Molecular structure of UO2(NO3)2 (TMMA):  Analog of species formed during U(VI) extraction with diamides
Molecular structure of UO2(NO3)2 TMMA): Analog of species formed during U(IV) extraction with diamides.

The fundamental separations research conducted in the RPL is founded upon the hypothesis that high selectivity for specific ions can be achieved by designing chemical agents (i.e., ligands) that sequester the ion to be separated. New ligands are designed by applying the principles of coordination chemistry. An integrated approach is taken combining the molecular modeling and chemical synthesis capabilities of the W. R. Wiley Environmental and Molecular Sciences Laboratory and the experimental radiochemical capabilities of the RPL.

Molecular modeling is used to guide the ligand design by screening potentially selective ligands. This computational screening allows experimentalists to focus on the most promising candidate ligands. This not only speeds up the discovery process, but also reduces laboratory wastes that would otherwise be generated by experimentally screening the potential ligands.

Potentially selective ligands are synthesized and their binding properties investigated. This is conducted through a variety of experimental techniques, including liquid-liquid extraction, spectroscopy (e.g., electronic absorption, FTIR, Raman, NMR), and thermochemical methods.

Crossflow filtration test apparatus
Cross-flow filtration unit for solid-liquid separation research (Enlarge image)

Applied Radiochemical Separations Research and Testing

The radiological capabilities of the RPL are exploited to transition separations methods from laboratory curiosity to industrial application. The RPL's expertise lies in development, scale-up, and deployment of processes to solve environmental problems. This expertise has developed over the last two decades in addressing processing issues associated with high-level and low-activity mixed tank wastes. Our clients rely on our capabilities in radiochemical science and engineering to develop and test process flowsheets for achieving specific separation goals. Typical technologies exploited include leaching, liquid-liquid extraction, ion exchange, and membranes.

The RPL resident research staff consists of a unique mix of scientists and engineers, who act in a synergistic way to provide our clients with innovative solutions to their radiochemical separations problems. Furthermore, these researchers have access to facilities that allow investigations using tracer level radioactivity up to accelerator- or reactor-based post irradiation quantities of radioactive material.

Point of Contact:
Gregg Lumetta, Actinide Science Team Team
(509) 375-5696

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RPL at a Glance

Solving Global Problems with Premier Staff and Facilities
Solving Global Problems with Premier Staff and Facilities