China Huaneng said the No. 3 unit at its Changjiang nuclear power phase II project entered commercial operation on September 17, making it the company's first large pressurized water reactor built under its controlling stake and Hainan's first "Hualong One" reactor.

The unit marks Huaneng's entry into commercial-scale third-generation pressurized water reactor operations, following its Shidaowan high-temperature gas-cooled reactor, the company said. It gives Huaneng a nuclear development portfolio combining a fourth-generation high-temperature reactor demonstration with third-generation pressurized water reactor commercial operations.

The Changjiang phase II project was China's first nuclear project to start construction during the 14th "Five-Year Plan" period. The company said the project will support national energy security and carbon peaking goals, serve Hainan's economic development and advance the restructuring of China's energy mix.

The project, Hainan's largest power construction project, plans two 1.2 GW nuclear units using domestically developed "Hualong One" third-generation pressurized water reactor technology, with equipment localization at 98.1%.

Once fully built, the project will generate 18 TWh of electricity annually, saving more than 6.32 million tonnes of standard coal and cutting about 11.6 million tonnes of carbon dioxide emissions a year, Huaneng said.