China has achieved a groundbreaking milestone in nuclear energy by becoming the first country to successfully transmute thorium into uranium for nuclear fission. This historic feat was accomplished at the experimental Thorium Molten Salt Reactor (TMSR) located in Wuwei, Gansu province, under the leadership of the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. The reactor confirmed the successful conversion of thorium-232 to uranium-233, marking a significant step in the thorium fuel cycle’s technical feasibility. This achievement not only solidifies China’s leadership in molten salt reactor research but also addresses the nation’s reliance on imported uranium, offering a sustainable alternative. Thorium, abundant in China, boasts advantages such as a negative temperature coefficient of reactivity, reducing radioactive release risks, and producing less hazardous waste. The TMSR, a fourth-generation reactor, integrates seamlessly with renewable energy sectors and industrial applications. Initiated in 2011, the project has seen rapid progress, with full-power operation achieved in 2024 and the first thorium loading completed in October 2025. The program, involving nearly 100 institutions and companies, has established a fully localized supply chain, paving the way for commercial-scale thorium-based energy by 2035.