ABSTRACT
The development of safe methods for disposal of highly radioactive wastes (HRW) is one of the most important factors for successful development of nuclear energetic and other industries that exploit radionuclides. Radioactive wastes arise in many processes that are connected with the reprocessing of materials containing radionuclides. The method of the closed nuclear cycle employed in Russia and other East European countries is to reprocess HRW before their disposal so that long-lived radionuclides, which are the most hazardous components of these wastes, may be isolated more completely. A liquid–liquid extraction system based on water-soluble polymers such as polyethylene glycol has been suggested for extraction of actinides from various salt solutions, including HRW. Sorption methods that use columns with ion exchangers or other sorbents for purifying liquid radioactive wastes are less popular in Russia and other East European countries than extraction methods. Nevertheless, these methods in special cases are used to separate some radionuclides.
