Research Progress of Advanced Spent Nuclear Fuel Reprocessing Technology

This paper provides a systematic review of recent advances in spent nuclear fuel reprocessing technologies both domestically and internationally, with a focused analysis on the technical characteristics, challenges, and future development trends of hydrometallurgical and pyrochemical reprocessing methods. The hydrometallurgical approach, which centers on the Purex process, has achieved industrial-scale application. However, it still exhibits limitations in processing high-burnup fuels and faces technical challenges such as solvent radiolysis and waste minimization. In contrast, pyrochemical reprocessing has garnered significant research attention due to its notable advantages, including high radiation tolerance and compatibility with metallic fuels for fast reactors. Countries such as the United States, Russia, South Korea, and Japan have initiated engineering validation efforts, with the relevant technologies having reached Technology Readiness Level (TRL) 7. In China, the field of hydrometallurgical reprocessing has seen the proposal of a novel Advanced Salt-Free Two-Cycle Process (APOR), which utilizes dimethylhydroxylamine as a reductant to enhance the efficiency and safety of plutonium separation. Concurrently, front-end technologies such as high-temperature oxidative volatilization and laser cutting have been developed to achieve efficient tritium capture and precise cladding separation. In the area of pyrochemical reprocessing, a technical route based on molten salt electrolysis has been established, along with a conceptual flowsheet for the main process. Key technological verifications have been successfully conducted, including electrolytic separation of uranium and plutonium, distillation purification, and treatment of waste salts. Future efforts should focus on improving the adaptability of these technologies to high-burnup fuels, promoting the engineering application of the APOR process, accelerating the development of hot testing and engineering-scale equipment for pyrochemical reprocessing, and actively exploring the application of artificial intelligence in process optimization. These advancements will provide robust support for China’s three-step nuclear energy strategy, encompassing “thermal reactor, fast reactor, fusion reactor”.