Automated Radionuclide Separations, Analysis and Sensing

Oleg Egorov and Jay Grate

Environmental Molecular Sciences Laboratory

Pacific Northwest National Laboratory

Richland, WA 99352

The research in our laboratories has been directed towards application of modern solution handling techniques towards automation of radionuclide separations/analyses methods and environmental radionuclide-specific sensing. Using separation-optimized sequential injection (SI) technique with radiometric and ICP MS detection, we developed automated separation and analysis procedures for a number of radionuclides of interest, such as ⁹⁰Sr, ⁹⁹Tc, and various actinide species. By fluidically manipulating the sorbent slurries within the SI instrument, we developed renewable column technique which can automatically replace the column bed for each separation. Renewable column techniques are advantageous for the separations that are subject to analyte carryover on the sorbent material, sorbent degradation, and strong or irreversible interactions. The SI-separation techniques are also useful for the automation of generator chemistries used in the production of short-lived isotopes of medical interest. Development of an enclosed ²²⁵Ac-²¹³Bi generator instrument will be presented as an example.

Our ongoing research is directed at the addressing the fundamental challenges of monitoring of non-gamma-emitting radionuclides in groundwater. Our overall approach is based on integrating selective separation chemistry and radiation detection within a single functional device. Approaches towards selective sensing of ⁹⁹Tc , ⁹⁰Sr, and actinides in groundwater will be discussed.