China Institute of Atomic Energy Successfully Completes Full-Process Experimental Verification of Post-Irradiation Fuel Assembly Reassembly Technology for Integrated Fast Reactor

Recently, the China Institute of Atomic Energy (CIAE) under China National Nuclear Corporation (CNNC) successfully completed the full-process experimental verification of post-irradiation fuel assembly reassembly technology for the integrated closed fuel cycle fast reactor nuclear energy system (referred to as the integrated fast reactor), and successfully developed a reassembly prototype, comprehensively verifying the technical feasibility. This achievement marks that CIAE has independently mastered the core technology of post-irradiation fuel assembly reassembly for fast reactors, laying a solid foundation for subsequent engineering applications and material and fuel research under higher irradiation dose conditions, and is of great significance for enhancing China's advanced nuclear fuel R&D level and promoting the development of the closed fuel cycle.

Assembly reassembly is a core step for enabling structural materials of the integrated fast reactor to be re-inserted into the core and subjected to high-dose irradiation testing. The core design of the integrated fast reactor imposes higher requirements on fuel assemblies; however, inspection data corresponding to the required irradiation doses are currently lacking. To this end, the project team of the Reactor Engineering Technology Research Institute pioneered a complete post-irradiation fuel assembly reassembly process and, relying on a self-built experimental verification platform, fully simulated the entire process including disassembly, secondary backfilling, reassembly, and post-assembly quality inspection of assemblies in a hot cell environment, achieving full-process verification.

As a typical "new quality productive force," the integrated fast reactor is the main reactor type for China's medium- and long-term large-scale sustainable development of nuclear energy. It can achieve leaps in three core indicators—breeding capability, transmutation capability, and uranium resource utilization efficiency—and is of great significance for safeguarding national energy, resource, and ecological security, building an advanced closed nuclear fuel cycle system, expanding multi-purpose nuclear energy scenarios, and seizing the strategic high ground of nuclear science and technology.