55% of the world’s coal is burned¹ in China’s 3,146 coal-fired power plants (CFPPs)² . Another 674 are under construction or being planned. More than 4 billion tons of Chinese coal were burned in 2023³, with its energy sector generating almost 80% of the country’s greenhouse gas (GHG) emissions.  Coal is dominant in China’s power generation, 67% of China’s current energy mix is provided by fossil fuels. While China’s production of photovoltaic panels has broken world records, and there has been a rapid national rollout of renewables and a big reduction in new coal power projects, China must be far more ambitious with its decarbonisation plans if we are to minimise the impact of GHG emissions towards further global climate change. Repowering CFPPs with Small Modular Reactors (SMRs) can rapidly accelerate China towards achieving net-zero, there are viable case studies which demonstrate the enormous potential of this innovative pathway, and the technological development in this field looks extremely promising.  

Nuclear power in China has increased rapidly since 2010 and occupies 5% of the electricity power mix, China’s current target is to reach an installed nuclear capacity of 70GW by 2025. The focus for nuclear energy development has been on planning large reactors (LRs) in coastal areas on the eastern side of the country, which are locations near to the energy demand centres for industry but many thousands of kms away from coal resources. LRs reactors are difficult to construct, especially for inland sites, and often require 12 years of commissioning and construction lead time. Repowering CFPPs with SMRs has not been given sufficient consideration by the Chinese government.  SMRs are generally a better choice for Coal-to-Nuclear retrofit conversions (C2N) than using LRs. SMRs are easier and faster to construct than LRs, the timeline of a C2N conversion of a CFPP site from initial site evaluation to connecting to the grid in China could perhaps be as little as 6 years. The Emergency Planning Zone for an SMR can be much smaller and, as quite a few of China’s coal-fired units are less than 300MW in size, SMRs look to be a feasible option in terms of retention of existing energy generation capacity.  

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SMRs and other advanced nuclear technologies can simultaneously provide power and heat for industrial applications, such as a steady steam and electricity supply for the petrochemical sector, as well as residential heating. Modular designs allow for mass production, with transportation by rail and truck to site installation. Standardisation of design allows for scalability by combining multiple modules. SMRs also have a much smaller land footprint than LRs, which makes them excellent candidates for replacing coal boilers on a CFPP site. Repowering CFPPs with nuclear technology drastically reduces carbon emissions and air pollution and creates and retains local job opportunities in the energy and industrial sectors. Existing infrastructure such as power transmission and distribution equipment, and heating pipelines can be reused in a Repowering project, which is both economically efficient and environmentally less impactful, as it does not rely on developing fresh greenfield sites from scratch (as in other renewables projects). Repowering could be an ideal solution for the northwestern regions of China in particular which are heavily reliant on coal power and may not have adequate available renewable resources such as wind and solar.  

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Screening Results for SMRs and LRs in China for C2N

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Dr. Sheng Zhou of Tsinghua University has performed a comprehensive screening of CFPP units by considering multiple site factors such as safety and reliability, environmental compatibility, technical feasibility, economic viability and public acceptance. Additional consideration has been given to seismic geology, distance from the border, population density and access to water sources. His research has determined a total of 402 potential CFPP units which could be suitable for Repowering using SMRs, and 219 candidates which could be suitable for Repowering by LR, which combined could boast a theoretical 200 - 300GW of energy generation by clean energy sources.  
Note: These are draft figures, and are pending confirmation of a full report which will be published by Dr. Zhou and his colleagues in December 2025.  

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A Shortlist of the SMR Reactors Being Developed in China

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The Chinese government’s National Energy Administration, along with major state-owned enterprises (SOEs), such as China General Nuclear Power Group, and other groups such as the Shanghai Nuclear Engineering Design Institute are heavily investing in the research and design of SMR technology. Several reactors are in different stages of preliminary design, and construction. Tsinghua University’s HTR-PM reactor, developed over a period of 30 years of research and collaboration with the SOE China Huaneng Group and China National Nuclear Corporation, has been operational for demonstration since Dec 2023 on the Shidaowan site in China’s northeast Shandong Province. 93.4% of the equipment for this project was manufactured domestically; a testament to the success of Chinese engineering in embracing nuclear technology.  

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The HTR-PM is a Generation IV high temperature, gas-cooled reactor (HTGR) pebble-bed module, featuring two small nuclear reactors (each of 250 MWt) which drive a single 210 Mwe steam turbine. Cooled by helium, it generates electricity and high temperature steam at temperatures up to 567℃, with inbuilt safety systems which can cool down the reactor naturally without human intervention or use of emergency core cooling systems. In terms of matching steam parameters, an HTGR such as the HTR-PM would best replace subcritical (545⁰C/17MPa) and supercritical (566⁰C/24.1MPa) coal-fired boilers. An alternative method of Repowering would be to also replace the existing steam turbine of a CFPP with a new one to improve the power generation efficiency (the steam parameters of an HTGR can be increased to 630⁰C/25MPa if required). Tsinghua University is working to scale up the HTR-PM to create the HTR-PM600, which integrates one steam turbine rated at 650 Mwe with six reactor modules.

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Other SMR reactors in China’s pipeline include China National Nuclear Corporation’s ACP100 which is under construction, and various pressurised water reactors (PWR) which are in the preliminary design stages, including the CAP200, DHR400, NHR200-II, and some smaller floating SMRs which can be deployed offshore, or on ships, such as the HHp25, ACPR50S and ACP100S.  

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2 Repowering Case Studies (Based on Draft Research – Full Report Due Dec 2025)

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1^st Case Study: Using a HTGR to Repower a CFPP – Fuzhou Coal Power Plant

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As a case study, Fuzhou Jiangyin is a 2,720MW CFPP, comprised of six coal-fired units, located in Fujian, a province in eastern China. 2 x 350MW units from the first phase of its construction have been in operation for more than 30 years. These could theoretically be replaced by using 6 HTGR NSSS modules (with a combined total thermal power of 1200MW, and secondary steam parameters of 620⁰C/25MPa), and one 600 MWe level ultra supercritical steam turbine unit, with a power generation efficiency of 48%. This system would generate 576 MWe of electrical power at the original voltage level of 220kV.  

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A Repowering project on the Fuzhou site would be both technologically and economically viable. The annual on-grid electricity could reach 4032 GWh, with a 30-year revenue of 52 billion Chinese Yuan ($7.1 billion). It would have a maximum annual steam supply of about 11.35 million tons, generating an additional revenue across 30 years of 85.1 billion Chinese Yuan ($11.7 billion), with an overall unit cost of 25,000 RMB/kW ($3,443/kW). Additional research would be required on site bedrock analysis and flood prevention work, and on the smooth integration of the nuclear and coal technologies.  

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2^nd Case Study: Coupling a NHR200-II SMR with a Petrochemical Park

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Chinese petrochemical parks are predominately supported by CFPP units. The NHR200-II is a light water-cooled reactor developed by Tsinghua University that is currently in a preliminary design stage. It provides steam at much lower parameters than an HTGR (201.4⁰C/1.6 MPa), yet this can meet the parameters of the thermal network of a petrochemical park, and the low, medium and high-pressure steam required by a petrochemical park for its production processes. A Repowering of a petrochemical park with one of these reactors has the potential for replacing 212,100 tons of coal per year, and reducing emissions by 551,500 tons of CO₂ per year.  

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Conclusion

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SMR technology can be integrated into a variety of Chinese industries where there is a requirement for heating and electrical power generation, including industrial and residential heating. Nuclear energy will be an important ongoing source for the Chinese power sector, providing an estimated16% - 26% of electricity demand in the long term, and 16% - 19% of the industrial heat supply. If China committed to building a 100% clean energy system on a large scale, using a combination of Repowering by C2N, and wind, solar and other renewables, this could place China in a very positive position of having passed its peak of fossil fuel reliance for good, setting it on a steady GHG emission reduction path towards a bright and equable future powered entirely by clean energy.  A demonstration of a first successful Repowering project in China will be essential to increasing government awareness and public acceptance of the pathway’s valuable potential.  

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¹ https://www.statista.com/statistics/265491/chinese-coal-consumption-in-oil-equivalent/

² Unless otherwise specified, all facts and figures are drawn from a presentation given by Dr. Sheng Zhou at the Repower South Korea Fall Summit 2024, titled ‘SMR Potential in Power and Heat Sector Decarbonization in China’. These are draft research figures, with his full report scheduled for Dec 2025.

³ https://www.reuters.com/markets/commodities/chinas-power-sector-emissions-surpass-4-billion-metric-tons-2023-2023-12-21/