China’s nuclear buildout continues to progress through methodical construction milestones rather than capacity announcements, and the completion of cold functional testing at Xudabao Nuclear Power Plant’s Unit 3 is one such inflection point.
Finalized on December 12, the test allows the unit to transition from mechanical installation into commissioning, a phase where schedule discipline and system integration typically determine whether projects stay on track.
Cold functional testing is not a symbolic step. It subjects the reactor coolant system and associated primary loop equipment to high-pressure conditions without nuclear fuel loaded, validating pressure boundary integrity, valve performance, instrumentation accuracy, and system interactions. For Generation III reactors such as the VVER-1200 deployed at Xudabao, this stage is particularly consequential because it confirms whether safety systems designed to meet post-Fukushima standards perform as engineered before heat-up and fuel loading begin.
Xudabao Unit 3 is part of a broader Sino-Russian nuclear cooperation framework formalized in 2018 and 2019, covering reactor construction and nuclear fuel supply. The VVER-1200 design, Russia’s flagship export reactor, has become a central component of this partnership, reflecting China’s strategy of combining domestic nuclear expansion with selective technology collaboration rather than full reliance on indigenous designs alone.
Construction sequencing at the site highlights a relatively steady execution pace. Unit 3 broke ground in July 2021, followed by dome installation in July 2023, placing the cold testing milestone roughly in line with typical timelines for large pressurized water reactors under current regulatory regimes. Unit 4, which began construction in May 2022, is following a staggered schedule that reduces peak labor and equipment bottlenecks, an approach increasingly favored in multi-unit nuclear projects to manage risk.
Commissioning is currently scheduled for 2027 for Unit 3 and 2028 for Unit 4, timelines that imply a multi-year period for hot functional testing, fuel loading, grid connection, and power ascension testing. These phases historically expose the most schedule sensitivity, particularly where first-of-a-kind integrations or cross-border supply chains are involved. While VVER-1200 technology is no longer novel, localization of components and coordination between Chinese and Russian contractors still introduce execution complexity.
Ownership structure also shapes project dynamics. Liaoning Nuclear Power Company Limited is controlled by CNNC with a 70% stake, alongside Datang International Power Generation Company at 20% and State Development and Investment Corporation at 10%. This configuration aligns state nuclear development priorities with power generation and investment entities, reinforcing the plant’s role not just as a capacity addition but as a strategic asset within China’s northeastern power system.
From a broader energy perspective, Xudabao underscores how nuclear remains a cornerstone of China’s long-term decarbonization strategy, particularly in regions where renewable integration is constrained by grid stability or seasonal demand patterns. The progress of Unit 3 into commissioning does not alter national capacity targets on its own, but it reinforces a pattern: large-scale nuclear projects in China are advancing incrementally, milestone by milestone, with fewer visible disruptions than many comparable projects globally. As commissioning approaches, attention will shift from construction quality to operational readiness, operator training, safety culture, and grid integration.
