Another Chinese Hualong One reactor successfully passes cold tests

A new Hualong One unit at China’s Changjiang nuclear power plant has reached an important milestone. The unit, with an installed capacity of 1200 MW, has completed cold hydrostatic tests. The tests were intended to verify the leak-tightness of the primary circuit and auxiliary systems. The nuclear unit, whose construction China officially began in 2021, will now undergo hot functional tests, followed by nuclear fuel loading. Engineers plan to start commercial operation in 2027.

China Huaneng Group announced that the third unit at its Changjiang nuclear power plant successfully completed cold tests on 10 April. During the tests, workers checked the leak-tightness of the primary circuit and associated components at pressures of up to 22.3 MPa for 10 minutes.

"The primary circuit is intact and leak-tight, marking the nuclear unit’s full transition from the installation phase to the commissioning phase. This also lays a solid foundation for the next steps," the company said in a press release.

The nuclear unit, construction of which began in March 2021, still needs to undergo hot functional tests, fuel loading, grid connection and tests at various power levels before entering commercial operation.

The new Changjiang 3 unit in China’s Hainan Province has a Hualong One reactor with a capacity of 1200 MW (gross) / 1000 MW (net). In addition to China Huaneng Group (51%), China National Nuclear Corporation (CNNC) holds a 49% stake in the power plant project.

Next to a small modular reactor

China began construction of the first phase of the Changjiang nuclear power plant in 2010. It commissioned two units with CNP-600 pressurized water reactors there in 2015 and 2016. In 2021, construction began on two Hualong One units as well as the Linglong One (ACP100) demonstration small modular reactor.

The modular reactor, which is also intended for heating, steam production and seawater desalination as well as electricity generation, has an electrical capacity of 125 MW. All units under construction at the plant are expected to enter commercial operation in 2026 and 2027.