China began building a 660-megawatt gas-cooled reactor that will steam a petrochemical park

Concrete went into the foundation of a 660-megawatt gas-cooled reactor in Jiangsu province, China, when China National Nuclear Corporation (CNNC) announced on Nov. 6 that the first batch had been poured for the unit’s nuclear island. The reactor is a high-temperature gas-cooled design called Chilong One, and its main customer is a petrochemical park next door rather than the electric grid alone. Construction of the gas-cooled unit starts nearly ten months after the plant’s first Hualong One reactor got its own first concrete.

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The site is the Jiangsu Xuwei Nuclear Heating and Power Plant in Lianyungang, very close to CNNC’s existing Tianwan station. China’s State Council approved Phase 1 in August 2024 as part of an 11-reactor batch, and the owner is CNNC Suneng Nuclear Power Company, a CNNC subsidiary responsible for investment, construction and operation. Phase 1 holds three units: two Hualong One pressurized water reactors rated at 1,208 megawatts net each, and the single 660 MWe gas-cooled unit now under construction.

Two reactor types feeding one steam network

The unusual part of Xuwei is the plumbing between the reactors. According to World Nuclear News, citing CNNC, the Hualong One units’ primary steam first heats demineralised water into saturated steam. The gas-cooled reactor’s primary steam then heats that saturated steam a second time, producing three grades of industrial steam at different temperatures and pressures for the customers in the petrochemical park. A new steam heat exchange station will run heat-to-electricity operation for the first time.

Output targets are large. Once Phase 1 is operating, CNNC projects about 32.5 million tonnes of industrial steam a year and maximum generation above 11.5 billion kilowatt-hours. The company says the plant will displace 7.26 million tonnes of standard coal and avoid 19.6 million tonnes of carbon dioxide annually, figures that Nuclear Engineering International also relayed when the project started building in January. All of these are design-stage projections from the owner, not measured results.

Chilong One and its Tsinghua lineage

Chilong One was developed jointly by CNNC and Tsinghua University and carries a design operating life of 60 years. CNNC calls Xuwei the first commercial application of a high-temperature gas-cooled reactor, a step beyond the Shidaowan demonstration plant in Shandong province. The engineering firm in charge of the gas-cooled unit, CNNC Energy Technology Company, served as EPC contractor at Shidaowan and provided nuclear island commissioning services there; CNNC holds a 46 percent stake in it.

Money for that work was scrutinized in August. A World Nuclear News report on the direct-procurement contract put the estimated transaction value at RMB 10.3 billion, about $1.5 billion, with the final price dependent on the transaction agreement, and said first concrete for the gas-cooled unit was expected by the end of 2026. The pour announced on Nov. 6 therefore landed inside that window. The contract covers design, equipment and material delivery, certification support, commissioning support, operator training and project management.

Conventional islands, firsts claimed and what remains open

The turbine-side buildings are a separate package. A CNY 4.2 billion contract (about $594 million) was awarded in September 2025 to a consortium of China Energy Engineering Jiangsu Electric Power Construction No 3 Company and China National Nuclear Huachen Construction Engineering Company, covering the conventional island power plants for all three units and some balance-of-plant work, as World Nuclear News reported in January.

Phase 1 has been building for ten months already. First concrete for Unit 1, a Hualong One, was poured on Jan. 16, 2026, and NucNet’s David Dalton reported the plant as a hybrid facility pairing one gas-cooled reactor with two pressurized water reactors. Nuclear Engineering International adds that the design is mainly an industrial heat supply, with electricity as a secondary output, which is the reverse of how most reactors are sized and sold.

Engineering detail from the same coverage gives a sense of how the coupling is being managed. Digital simulation supports the coupled control logic that has to keep both reactor types and the shared steam station in step, and laser-tracked metal active gas welding is reported to be at least three times more efficient than manual shielded metal arc welding on the piping. Nothing in those reports gives independent verification of the efficiency figure, which comes from the project side.

CNNC bills Xuwei as the world’s first large-scale nuclear-petrochemical coupling project and the first to link a pressurized water reactor with a gas-cooled one. NucNet, in its own account of the January pour, described the plant as a hybrid facility supplying both industrial heat and electricity, with heat the primary job. CNNC says the project is advancing smoothly according to plan and that commercial gas-cooled reactors can supply heat to energy-intensive industries worldwide.

What the announcement does not supply is a start-up date for the gas-cooled unit, and the 32.5-million-tonne steam figure remains CNNC’s own projection until the coupled system runs. Whether three different steam grades can be drawn from two reactor types without disturbing either one is the question that the “reactor-machine-heat” control scheme CNNC describes will have to answer in commissioning.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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