China's nuclear energy program has achieved a significant milestone with the successful commissioning of the Changjiang Unit 3 reactor, a Hualong One pressurized water reactor. This development marks a crucial step towards the operation of the HPR1000 reactor, which is set to become a cornerstone of China's expanding nuclear energy fleet.
The Hualong One reactor, designed jointly by China National Nuclear Corporation (CNNC) and China General Nuclear (CGN), is a testament to China's commitment to indigenous nuclear technology. With its active and passive safety systems, double-layer containment structure, and 60-year design life, the Hualong One reactor is a robust and reliable solution for nuclear power generation.
The Changjiang Unit 3 reactor, located in Hainan Province, is the first of two Hualong One reactors being built during the second phase of the Changjiang Nuclear Power Plant. The construction of these reactors represents a substantial investment of around CNY 40 billion (approximately US$5.9 billion) and is expected to be fully operational in early 2027.
The achievement of first criticality is a crucial milestone in the commissioning process of the reactor. It signifies the moment when the reactor becomes capable of sustaining a controlled nuclear fission chain reaction without requiring an external neutron source. While the reactor does not immediately begin producing electricity at this stage, it represents one of the final technical hurdles before synchronization with the power grid.
Following first criticality, engineers will conduct a series of low-power physics tests, gradually increase reactor output, and verify the performance of safety systems before the unit is connected to the grid and eventually enters commercial service. This meticulous process ensures the safety and reliability of the reactor before it is integrated into the power grid.
The Changjiang Nuclear Power Plant is becoming one of China's most diverse nuclear sites, housing not only conventional large reactors but also an advanced small modular reactor, the Linglong One (ACP100). This combination of conventional and advanced nuclear technologies positions Changjiang as a strategically important hub for China's nuclear energy program.
The successful startup of Unit 3 reflects China's broader nuclear expansion program and its commitment to reducing reliance on fossil fuels while supporting economic growth and rising electricity demand. As the Changjiang Unit 3 progresses through commissioning, it moves one step closer to joining China's rapidly growing fleet of commercial nuclear reactors, contributing to the country's ambitious low-carbon energy ambitions.
