Separation of Radionuclides from Aqueous Mixed Waste Solutions Using Liquid–Liquid Extraction Processes

The presence of long-lived radionuclides in aqueous mixed wastes can significantly increase the complexity and cost of treating the waste for disposal. Incidental wastes resulting from processes utilizing nuclear fission may contain radionuclides (e.g., ¹³⁷Cs and ⁹⁰Sr) that require remote handling of the waste and process equipment. Other wastes that contain actinide elements (U, Np, Pu, Am, or Cm) or radionuclides of lanthanide elements (Ce, Sm, and Eu, for example) require, at a minimum, extensive containment controls, if not limited shielding to handle the waste. Separation of the major radioactive elements from the waste allows downstream processing to be performed in less expensive equipment and facilities with hands-on operation and maintenance. This lowers capital and operating costs of treatment facilities.