First concrete poured for Haiyang Phase III unit 5 nuclear island

China Nuclear Industry 24 Construction Co Ltd (CNNC 24), a subsidiary of China National Nuclear Corporation contracted by State Power Investment Corporation for civil construction of the Haiyang Phase III nuclear islands, completed the first concrete pour for unit 5 on 31 October. The milestone marks the official start of main construction for the unit and signals the entry of the broader Phase III project into full-scale construction.

The pour involved approximately 6,626 cubic metres of concrete and was expected to take nearly 62 hours to complete. CNNC 24 described the operation as technically demanding, citing the large single-pour volume, extended duration, and complex construction logistics. The contractor drew on experience accumulated during the construction of Haiyang's Phase I and Phase II units, applying optimised construction sequencing, design refinements, and advance scheme reviews to manage the complexity.

Regulatory and project background

Construction of Haiyang units 5 and 6 received State Council approval on 27 April 2025. Construction permits for both units were subsequently issued by the National Nuclear Safety Administration. The two reactors are CAP1000 units — the Chinese derivative of the Westinghouse AP1000 passive pressurised water reactor design.

Haiyang Phase I comprises two AP1000 units that entered commercial operation in October 2018 and January 2019 respectively. Phase II, also consisting of two CAP1000 reactors, began construction in July 2022 and April 2025, with both units scheduled to reach full operation in 2027.

Site capacity outlook

Upon completion and commissioning of units 5 and 6, the Haiyang plant would become, according to CNNC 24, the world's largest nuclear energy base operating exclusively on passive pressurised water reactor technology. The expanded site is projected to generate 60.9 billion kilowatt-hours of electricity annually and provide district heating capacity exceeding 150 million square metres, covering 25 county-level cities.

NRC Completes Safety Review for Xe-100 Plant in Texas, Clearing Path to Construction Permit

Safety Review Milestone Reached

The US Nuclear Regulatory Commission released its Final Safety Evaluation Report for the Long Mott Generating Station construction permit application on 30 October. The report covers the NRC staff's assessment of the plant's principal design criteria, preliminary design, safety analyses, probabilistic risk assessment, and associated research and development programmes. The staff concluded that the proposed plant and site provide an adequate safety basis to proceed with construction under applicable US nuclear regulations.

The NRC had previously completed its environmental review in May, when it issued an Environmental Assessment and Finding of No Significant Impact. With both the safety and environmental reviews now finalised, the project has advanced to the final stages of the NRC's construction permit review process. The regulator indicated via its social media channels that a construction permit announcement should be expected shortly.

Project Overview

Long Mott Energy, a wholly owned subsidiary of The Dow Chemical Company, submitted the construction permit application in March 2025. The proposed facility would consist of four Xe-100 high-temperature gas-cooled reactors with a combined thermal output of 800 MWt, equivalent to 320 MWe of electrical capacity. The plant is intended to supply electricity and process steam to Dow Chemical's Seadrift Operations in Texas, with any surplus power exported to the wider electrical grid.

X-energy has described the project as the first grid-scale advanced nuclear reactor proposed for deployment at an industrial facility in US history. The Xe-100 is also the first high-temperature gas-cooled reactor construction permit application to be reviewed under the NRC's technology-inclusive, risk-informed, and performance-based licensing framework, a regulatory pathway designed to accommodate non-light-water reactor designs.

Regulatory and Technical Background

X-energy's commercial licensing effort has been supported by pre-application engagement with the NRC dating back to 2018, alongside decades of US Department of Energy research into high-temperature gas-cooled reactor technology. The combination of early regulator engagement and a novel licensing framework has shaped the review process for the Xe-100 application.

Dragan Popovic, Chief Global Operating Officer at X-energy, noted that the NRC's completion of the safety review reflects sustained effort by both the company's team and NRC staff, and that the foundations established through this process are intended to support future Xe-100 applications as the technology moves toward broader deployment.

US DOE ARPA-E Awards Eight Grants Under HORNIG Programme for TRU Fuel Development

Programme Overview

The High-performance Optimised Recycled Nuclear Isotopes for Gen IV reactors (HORNIG) programme, administered by the US Department of Energy's Advanced Research Projects Agency-Energy, has announced eight funded projects targeting the design, fabrication, and qualification of transuranic (TRU) fuels. The programme seeks to overcome technical and economic barriers that have historically limited TRU fuel use in commercial reactors, with a stated goal of compressing qualification timelines from decades to fewer than seven years. HORNIG builds on earlier ARPA-E nuclear energy initiatives, including the CURIE programme launched in 2022.

TRU fuels incorporate transuranic elements — radioactive isotopes with atomic numbers above uranium, including neptunium, plutonium, americium, and curium — that are present in existing inventories of used nuclear fuel. The programme aims to convert these materials into fissile feedstocks suitable for advanced reactor designs.

Award Recipients and Project Scope

The eight awards span a range of fuel technologies and reactor types.

  • Westinghouse Electric Company: USD 7 million for its PowerBlock nuclear fuel technology, which combines new fuel architectures with advanced manufacturing to target 24-month fuel cycles at thermal power levels above 4,200 MW.
  • Standard Nuclear: USD 7 million for its Mixed Oxycarbide (MCO) TRISO project, developing TRISO particle fuel containing recycled transuranic and uranium feedstock for high-temperature gas reactors. The project is being conducted in partnership with SHINE Technologies.
  • Oklo Inc: USD 6.8 million for its FORGE project, developing transuranic-bearing U-TRU-Zr metallic fuel for sodium-cooled reactors, with a focus on fabrication methods and qualification-relevant data generation.
  • Exodys Energy Inc: USD 1.3 million to develop a common evaluation framework covering TRU fuel feedstocks, fuel-cycle costs, transportation, and deployment requirements across HORNIG fuel concepts.
  • Texas A&M University: USD 5.4 million to develop and test a liquid thorium-based nuclear fuel salt incorporating transuranics for molten salt reactors.
  • Oregon State University: USD 7 million for a low-temperature fabrication process to produce recycled transuranic-bearing nitride fuel for advanced reactors.
  • Sandia National Laboratories: USD 3.4 million to develop an uncertainty-aware decision support capability for scaling TRU fuel production across HORNIG concepts.
  • Idaho National Laboratory: USD 7 million for its IMPACT project, developing and testing a chloride fuel salt containing recycled transuranic elements for molten salt reactors.

Industry and Policy Context

Standard Nuclear stated that its MCO TRISO initiative is intended to establish an alternative to high-assay low-enriched uranium, with the aim of diversifying fissile feedstock supply chains for both existing and next-generation reactors while reducing commercial used fuel stockpiles.

Westinghouse Electric's PowerBlock technology is positioned to address utility demand for extended fuel cycles and improved plant economics, according to the company.

The awards reflect a broader federal policy emphasis on domestic nuclear fuel security and reducing dependence on foreign fuel suppliers, as articulated by US Deputy Secretary of Energy James Danly in connection with the announcement.