Closed-cycle nuclear fuel has important strategic significance for the sustainable development of nuclear energy. Among them, spent fuel recycling is the core of a closed-end nuclear fuel cycle, which can increase the utilization of uranium resources, minimize radioactive waste, and properly resolve high-level emissions. Disposal and disposal of waste. At present, the internationally accepted method for treating high-level radioactive waste is to convert long-lived, high-radioactive nuclide into a short-lived and moderately-lived or stable nuclide through an accelerator-driven subcritical reactor (ADS). The spent fuel of the water reactor undergoes high-temperature redox treatment to remove most of the volatile fission products. The remaining radioactivity mainly depends on the U, Pu and Np, Am, Cm and other minor tantalum nuclides. The method and device for preparing nuclear fuel pellets for regenerating nuclear fuel is the core link of the transmutation system.
Institute of Modern Physics, Chinese Academy of Sciences, Institute of Transmutation, in collaboration with the PSL Institute in Switzerland, systematically studied the chemical kinetics of the sol-gel process and found that the composition of the solution can be changed at room temperature in a short time. The sol-gel process is completed. A rapid sol-gel method combining room-temperature instant-free cooling and microwave-assisted heating is proposed to prepare novel nuclear fuel pellets containing secondary steroids in a glove box. The scientists established an experimental platform for the preparation of nuclear fuel pellets containing secondary lanthanide nuclei at the PSI Institute of Modern Physics in Switzerland and successfully prepared a simulated nuclear fuel CeO with a particle size of 500 μm. 2Spherule. This method effectively avoids the radiation decomposition of gels by alpha and gamma rays of the secondary tethered nuclide and the generation of secondary organic radioactive waste.
The research work has been supported by the Chinese Academy of Sciences' strategic pilot technology project (A class) 'Future Advanced Nuclear Fission Energy - Advanced Transmutation System' project and the National Natural Science Fund project. Related research results were published on Ceramics International.
Figure 1. Chemical kinetics of the sol-gel process
Figure 2. Schematic diagram of the sol-gel principle for the combination of immediate-uncooled mixing and microwave heating
Figure 3. CeO
2Gel ball
