Hot testing completed at first Zhangzhou unit

Hot functional tests involve increasing the temperature of the reactor coolant system and carrying out comprehensive tests to ensure that coolant circuits and safety systems are operating as they should. Carried out before the loading of nuclear fuel, such testing simulates the thermal working conditions of the power plant and verifies that nuclear island and conventional equipment and systems meet design requirements.

China National Nuclear Corporation (CNNC) noted that during the hot testing of Zhangzhou 1, workers completed the full-load load test of the diesel generator, main system passivation, and 111 commissioning tests, as well as 73 regular operation tests.

Cold functional tests - which are carried out to confirm whether components and systems important to safety are properly installed and ready to operate in a cold condition - were completed at Zhangzhou 1 in early November last year. The main purpose of those tests - which marked the first time the reactor systems were operated together with the auxiliary systems - was to verify the leak-tightness of the primary circuit.

The Zhangzhou site (Image: CNNC)

China's Ministry of Ecology and Environment issued construction licences for Zhangzhou units 1 and 2 on 9 October 2019 to CNNC-Guodian Zhangzhou Energy Company, the owner of the Zhangzhou nuclear power project, which was created by CNNC (51%) and China Guodian Corporation (49%) in 2011. Construction of unit 1 began one week after the issuance of the construction licence, with that of unit 2 starting in September 2020.

"According to the plan, unit 1 will generate electricity within the year, which will drive the economic and social development of southern Fujian and serve as a new development engine for the region to achieve carbon peak and carbon neutrality goals," CNNC said. It noted that preparations are currently under way for cold functional tests at unit 2.

In September 2022, China's State Council approved the construction of two further Hualong One units as Phase II of the Zhangzhou plant. First concrete for the nuclear island of unit 3 was poured on 22 February this year. CNNC said first concrete for unit 4 is expected "within the year".