Xuwei HTGR: CNNC Pours First Concrete for 660 MWe Chilong One Unit

China National Nuclear Corporation (CNNC) announced the first nuclear-island concrete pour on Nov. 6 for unit 3 of the Jiangsu Xuwei Nuclear Heating and Power Plant, a 660 MWe Chilong One high-temperature gas-cooled reactor (HTGR), according to World Nuclear News.

The pour marks the start of construction of the unit. CNNC's listed arm, China National Nuclear Power, had announced the planned date the evening before in a Shanghai exchange filing, reported by China Securities Journal. The filing gives a rated power of 660,000 kW, Chinese HTGR technology and a 60-year design life. It also says the company's controlled units under construction now number 15, with 17,023,000 kW of capacity. The Chilong One was developed jointly by CNNC and Tsinghua University. "The project construction is progressing smoothly according to plan," CNNC said.

For Voltgrid readers, the design is the point. The HTGR is the same reactor family as X-energy's Xe-100, the design in two projects Amazon supports: it funds the feasibility phase at Energy Northwest's Cascade project in Washington and development of an AEP feasibility project in Indiana, where it intends to buy the power. Xuwei is designed to supply a petrochemical park with steam and power. In the US, Dow's planned Long Mott plant in Texas would supply power and process steam to Dow's Seadrift site if the NRC issues the permit and Dow builds it, while Amazon's Xe-100 projects are about electricity.

How Xuwei's HTGR Makes Industrial Steam and Power

Xuwei's Phase I plans two Hualong One pressurized-water reactors of 1,208 MWe net each beside unit 3, at Lianyungang in Jiangsu province, close to CNNC's Tianwan plant. In the design scheme, steam from the Hualong One units turns demineralized water into saturated steam, and steam from the HTGR then reheats it into three grades of industrial steam for the park, WNN reported. Once the whole phase runs, CNNC targets 32.5 million tonnes of industrial steam a year and maximum generation above 11.5 billion kWh. China's State Council approved Phase I in August 2024, and unit 1 poured its first nuclear-island concrete in January 2026.

The owner is CNNC Suneng Nuclear Power Company. CNNC Energy Technology Company, 46% owned by CNNC, is to handle HTGR design, equipment procurement and commissioning support, according to WNN's account of CNNC's plan. It was the nuclear-island contractor at the Shidaowan HTGR demonstrator in Shandong. In August, WNN reported that CNNC estimated the HTGR engineering contract at RMB10.3 billion ($1.5 billion), subject to a shareholder vote and the final agreement. A separate CNY4.2 billion contract for the three units' conventional islands was awarded in September 2025.

CNNC calls Xuwei the world's first commercial application of an HTGR, among several firsts it claims for the plant. WNN reported the claim as CNNC's. WNN also reported that the Shidaowan HTGR demonstrator entered commercial operation in December 2023, so the phrase refers to commercial application of HTGR heat to industry.

How an HTGR Supplies Industrial Steam

A high-temperature gas-cooled reactor (HTGR) cools its core with helium instead of water, so heat can leave the reactor much hotter than in a conventional plant. X-energy rates each Xe-100 module at 200 MWt of heat and 80 MWe of electricity, with a 750 C outlet temperature, and says the plant can send the heat out as industrial steam or as power.

At Xuwei, CNNC plans to use HTGR steam to reheat saturated steam from two Hualong One reactors into three grades of industrial steam for a petrochemical park, WNN reported. For supply, that sizes a reactor by a factory's steam demand as well as the grid, and ties its start date to a licence: Dow's four-module Long Mott plant (800 MWt, 320 MWe) still awaits its US construction permit.

Shidaowan Precedent and the US HTGR Timeline

No grid-connection or operation date for unit 3 appears in the announcements. The nearest precedent is slow. At Shidaowan, two 250 MWt reactors drive one 210 MWe turbine. First concrete was poured in December 2012, the plant connected to the grid in December 2021, and China's National Energy Administration declared commercial operation on Dec. 6, 2023, WNN reported. CNNC has not published the unit's thermal output (MWt), so a like-for-like comparison with US designs is not yet possible.

In the US, no new commercial HTGR has a construction permit yet. Dow's Long Mott plant, four Xe-100 units of 800 MWt and 320 MWe in total, received the Nuclear Regulatory Commission's final safety evaluation on Oct. 30. The NRC has said a permit announcement will come soon, but none appeared on its news list as of Nov. 8. Amazon's Cascade project is still in pre-application, and X-energy targets commercial operation in the early 2030s. That leaves project risk open for Cascade: a permit application, financing and a decision to build, with Amazon not obliged to buy, as our Nov. 1 analysis of Amazon's Xe-100 bet argued.

What to Watch Next for Xuwei and Long Mott

The next markers are the Long Mott permit decision and X-energy's third-quarter results on Nov. 12. At Xuwei, the open questions are a published operation target for unit 3 and its MWt rating and fuel details. Until CNNC states them, the Shidaowan timeline is the only operating evidence for how long a Chinese HTGR takes to reach the grid.