Objective Against the backdrop of global low-carbon energy transition, Coal-to-Nuclear (C2N) provides a critical pathway for revitalizing existing coal-fired power assets and breaking the carbon lock-in effect. This paper systematically reviews the adaptation principles and engineering practices of C2N, and compares the differences between domestic and international technical routes.

Method Domestic and international research and engineering practices of C2N were sorted out, and the technical characteristics and engineering progress of different technical routes were compared.

Result Overseas practices represented by the United States and Poland focus on site reuse of small modular reactor (SMR) and pressurized water reactor (PWR), and have developed site selection and evaluation tools. Nevertheless, these projects mainly adopt a full-replacement scheme, and no operational engineering projects have been completed to date. Considering that China's coal-fired power units have an average service life of approximately 15 years, China has developed a differentiated "boiler-replacement" technical route coupling high-temperature gas-cooled reactor (HTGR) with molten salt thermal energy storage to realize flexible coupling between nuclear reactors and steam turbines via thermal energy storage. At present, C2N development still faces prominent challenges, including ambiguous technical routes and the absence of dedicated nuclear safety standards.

Conclusion Future efforts shall strengthen verification of thermal storage coupling technology, promote coastal demonstration projects, improve the nuclear safety review and approval system, and align with China's Certified Emission Reduction (CCER) market, so as to provide technical and policy support for the low-carbon retrofitting of coal-fired power units.