China loads fuel into Changjiang 3, advancing toward startup phase

The first fuel assemblies went into Changjiang 3 on April 30, a milestone that moved the Hualong One unit out of construction and into nuclear commissioning. The loading of 177 assemblies is the point where a plant stops being a project on paper and becomes a reactor core preparing for startup, with the next steps leading through testing, grid connection and, eventually, commercial operation.

Changjiang 3 is the first of two Hualong One reactors in the second phase of the Changjiang nuclear power plant in Hainan province. China National Nuclear Corporation said fuel loading was a crucial step toward later grid connection and power generation, and that it laid a foundation for the unit’s next target. For a site already familiar with nuclear operations, the significance is less about the act of construction than the countdown it signals toward first electricity.

The pace of the build shows how far the project has already come. First concrete for Changjiang 3’s nuclear island was poured in March 2021, and the outer dome of the containment building was completed in October 2024. Earlier reporting had placed units 3 and 4 on track to be fully operational in early 2027, while CNNC materials separately said the two Hualong One units were due to enter commercial operation by the end of 2026. Fuel loading now puts unit 3 firmly into the final regulatory and commissioning sequence.

Changjiang’s importance goes beyond a single unit. The site already runs two CNP-600 pressurised water reactors that entered commercial operation in 2015 and 2016, and it is also home to a demonstration ACP100 small modular reactor, known as Linglong One. CNNC announced the ACP100 project in July 2019 and began construction in July 2021, describing it as the world’s first commercial onshore small modular reactor to start construction. CNNC says the ACP100 is designed not just for electricity, but also for heating, steam production and seawater desalination, which makes Changjiang an increasingly mixed nuclear complex rather than a conventional single-purpose plant.

The broader picture is one of steady repetition at scale. Changjiang 3 joins a run of Chinese Hualong One startup milestones in 2026, including Zhangzhou unit 2, Taipingling unit 1 and San’ao unit 1. For Hainan, another near-finished unit means more firm supply on a grid that needs it. For China’s nuclear buildout, it is another sign that standardized reactor deployment is still moving from concrete and steel to the far more consequential moment when fuel meets the core.