Cover Story | The Tianwan Model: Is Nuclear Energy More Than Just Power Generation?

Innovative applications of nuclear energy in district heating and industrial steam are opening up an entirely new frontier for nuclear utilization.

Along the coast of Lianyungang, on the shores of the Yellow Sea, the Tianwan Nuclear Power Plant’s eight reactor units stretch in a neat row. With six operating units, the plant boasts a total installed capacity exceeding 6.6 million kilowatts, generating roughly 158 million kilowatt-hours of clean electricity each day—power that flows continuously through transmission lines into the East China Grid, providing a steady boost to regional economic development. Meanwhile, just over 20 kilometers away, in the Xuhu New Area of Lianyungang, the petrochemical industry base features a dense array of refining and chemical processing facilities. As one of China’s seven major petrochemical hubs, the region is rapidly advancing toward its ambitious industrial target: 40 million tons of crude oil refining, 4 million tons of aromatics, and 3 million tons of ethylene.

These two “energy and industrial hubs” of national importance, though located close to one another, each face new challenges in their respective development paths. The Tianwan Nuclear Power Plant, endowed with abundant nuclear energy, seeks to transcend the limitations of single‑purpose electricity generation. Meanwhile, the Lianyungang Petrochemical Base, whose demand for industrial steam is steadily rising, is constrained by the high carbon emissions associated with conventional coal‑fired steam supply and aspires to secure a continuous, clean steam supply.

Today, thanks to breakthroughs in nuclear‑based steam‑supply technology, this “close neighbor” has finally achieved energy integration, and the Tianwan Nuclear Power Plant has taken on a new mission: producing industrial steam, thereby addressing the challenge of green steam supply for industry through a cross‑sectoral approach.

The “2024–2025 Energy-Saving and Carbon-Reduction Action Plan” and the “Opinions on Promoting Green and Low-Carbon Transformation and Strengthening National Carbon Market Development,” among other policies, have been successively introduced. These policies encourage large-scale petrochemical and chemical industrial parks to explore the use of nuclear energy for steam and heat supply, and specify that by 2027, the national carbon market will broadly cover the major emitting sectors in the industrial domain. As an environmentally friendly and cost-effective solution for industrial steam needs, nuclear‑based steam supply holds significant potential for future growth.

A New Cross-Industry Track

For a long time, industrial steam has been produced primarily using fossil fuels. As a major steam consumer, the petrochemical and chemical industries face substantial pressure to reduce carbon emissions. Data show that CO₂ emissions from production processes in these sectors account for roughly 13% of the nation’s total carbon footprint, with steam largely supplied by coal-fired power units. In recent years, China’s industrial steam market has exhibited a steady growth trend. The conventional use of fossil fuels in industrial steam production generates emissions such as carbon dioxide and sulfur dioxide. Against the backdrop of the “dual carbon” goals, the petrochemical and chemical industries are under immense pressure to cut their carbon footprint.

The traditional steam‑supply model can no longer be sustained. Against this backdrop, the Tianwan Nuclear Power Plant took the lead in “crossing over” into new fields, giving rise to the “Heqi No. 1” project—the country’s first industrial‑scale nuclear‑steam supply initiative.

The technological innovation behind the “Heqi No. 1” project is at the heart of its cross‑industry success. The project utilizes the secondary‑loop main steam from Units 3 and 4 of the Tianwan Nuclear Power Plant, employing steam‑to‑steam heat exchangers to produce industrial steam, which is then transported via a long‑distance pipeline network to the Xuhui Petrochemical Industrial Park in Lianyungang, more than 20 kilometers away. Its core principle is akin to the shell‑and‑tube heat exchange used in a “self‑heating pot”: the secondary‑loop steam from the reactor exchanges heat with demineralized seawater without direct contact. After being heated and further processed through a heat exchanger, the resulting industrial steam reaches parameters of 1.8 MPa(a) and 248°C, fully meeting the petrochemical complex’s requirements.

To ensure efficient steam transmission, the technical team developed a seven-layer pipe insulation design that achieves a temperature drop of less than 1°C per kilometer—far below the conventional standard of 3°–5°C—enabling 248°C high‑temperature steam to reach the industrial park reliably. From design and development through construction, the project spanned six years and secured 37 technological innovation patents, overcoming numerous technical challenges while significantly enhancing nuclear energy utilization efficiency. While conventional nuclear power plants achieve an efficiency of approximately 37%, “Heqi No. 1” directly harnesses thermal energy to implement cascaded energy use, boosting the unit’s actual thermal efficiency from 37% to 42% and marking a qualitative leap in energy utilization.

Since officially entering commercial operation on June 19, 2024, “Heqi No. 1” has maintained safe and stable operation for over 10,000 hours, with no unplanned load reductions or unexpected shutdowns. The project can supply 4.8 million tons of industrial steam annually, covering 30% of the steam shortfall in the Lianyungang Petrochemical Park. It also helps the petrochemical base save more than 700,000 tons of carbon emission allowances each year, reduce thermal discharge by over 14 million tons, and conserve approximately 400,000 tons of raw coal.

In addition to ensuring a secure supply, economic viability is another key consideration. According to a joint study conducted by the China Nuclear Energy Association and other organizations, the cost of nuclear‑based heating—covering both space heating and steam supply—is comparable to that of coal‑fired heating and offers an advantage over gas‑fired heating, thereby achieving a win‑win outcome in terms of environmental protection and cost efficiency. This has not only built a solid foundation for the integrated utilization of nuclear energy but has also paved an effective pathway for the green use of industrial steam.

Explore new pathways

The successful implementation of “Heqi No. 1” represents a harmonious convergence of favorable timing, geographical advantages, and popular support. The Tianwan Nuclear Power Plant generates surplus steam, while the Lianyungang Petrochemical Base, located just over 20 kilometers away, boasts substantial steam‑demand. Coupled with supportive policies and robust technological backing, this has laid a solid foundation for the replication and wider deployment of nuclear‑based steam supply.

Xu Yuejin, Secretary of the Commission for Discipline Inspection at Jiangsu Nuclear Power Co., Ltd., stated that the successful operation of “Heqi No. 1” marks a significant milestone: following the phases of electricity generation and residential heating, China’s integrated nuclear energy utilization has now expanded into the industrial steam‑supply sector. Over the past year, “Heqi No. 1” has operated safely and reliably, and through continuous experience‑building and technological breakthroughs, it has set a benchmark for the deployment of nuclear‑based industrial steam supply in subsequent nuclear power projects.

Building on the experience gained from the “Heqi‑1” project, China National Nuclear Corporation has further advanced its technical approach to “nuclear‑based steam supply.” Innovatively combining a pressurized water reactor with a high‑temperature gas‑cooled reactor, the scheme leverages the former’s high temperature and the latter’s large steam output by operating them in series, thereby generating industrial steam that is both abundant in quantity and superior in quality. The first phase of this novel initiative—the Jiangsu Xuhu Nuclear Heating and Power Plant Phase I—received State Council approval on August 19, 2024, and is designated as a key project under the national “14th Five‑Year Plan for a Modern Energy System.” The project is being implemented by CNNC Sune, with an initial master plan and phased construction of two separate heating systems. Together, it will comprise four HPR1000 reactors and two HTR‑PM600S high‑temperature gas‑cooled reactors, making it the world’s first demonstration project integrating a pressurized water reactor with a high‑temperature gas‑cooled reactor for district heating. This pioneering effort holds significant importance for opening up new frontiers in the comprehensive utilization of nuclear energy and for advancing the nation’s goals of peaking carbon emissions and achieving carbon neutrality. Commercial operation is scheduled for 2030.

In addition to the Xuhu Project, numerous domestic nuclear power bases have joined the effort to explore nuclear‑based steam supply. Sanmen Nuclear Power, Fuqing Nuclear Power, and Hainan Nuclear Power have already initiated the design and construction of nuclear‑steam‑supply projects, while Qinshan Nuclear Power, Zhangzhou Energy, and Haiyang Nuclear Power are actively conducting feasibility studies to lay the groundwork for the next phase of implementation. According to projections, by 2030, more than 30% of China’s nuclear power sites will have adopted nuclear‑steam‑supply programs. This target stems not only from the successful demonstration of “Heqi No. 1” but also aligns with the national dual‑carbon strategy and the growing need for a green transformation of industry.

It is worth noting that, at present, China’s power market reform continues to deepen, and nuclear power is gradually transitioning from traditional guaranteed‑purchase arrangements to market‑based trading. As electricity prices become increasingly influenced by market supply and demand, the single‑revenue model for nuclear power projects exposes them to certain market risks. Meanwhile, the implementation of nuclear‑powered steam supply has created a dual‑revenue “power generation + steam supply” engine for nuclear projects, effectively broadening their revenue streams.

From single‑source power supply to residential heating, and now to industrial steam generation, the Tianwan Nuclear Power Plant’s “cross‑sectoral expansion” and “replication” have not only unlocked the “green key” of nuclear‑chemical coupling but also opened up a “multi‑dimensional space” for the integrated utilization of nuclear energy.