Keystone and stumbling blocks in the use of ionizing radiation for recycling plastics

The International Atomic Energy Agency (IAEA) has launched the NUTEC Plastics initiative (NUclear TEchnology for Controlling Plastic Pollution), to mitigate plastic pollution, covering two areas: monitoring and impact assessment of microplastic in marine environments and addressing innovation in the treatment of plastic waste using radiation technologies. The latter approach is presented here, with a focus on the application of radiation-driven processes in the sorting, compatibilization, degradation, and thermal conversion of plastic waste and the main priorities for current projects. Keeping in mind the economic implementation of these approaches for the recycling of plastic waste, the latest trends in the development of powerful electron accelerators are presented and evaluated. Among the most promising application areas are irradiation methods for large-scale immobilization of plastic waste into road and building materials, combining virgin plastics with post-consumer plastics, and thermo-radiolysis, i.e. simultaneous irradiation and heating for synergistic decomposition of macromolecules/polymers. •The recycling of plastics can be enhanced by implementation of radiation technologies.•Radiolysis increases the compatibility of plastics with building materials components.•The difference in the lifetimes of radiolytic intermediates can be exploited for the sorting of polyolefins.•Radiolytic degradation can enhance the pyrolytic conversion of plastics.