Cold functional tests have been completed at unit 8 of China’s Tianwan NPP in Jiangsu province. China National Nuclear Corporation (CNNC) said completion of the tests “marks the full transition of Tianwan unit 8 from the installation phase to the commissioning phase, laying a solid foundation for subsequent hot functional tests and fuel loading”.
The tests – the first time the reactor systems are operated together with the auxiliary systems – are intended to verify the leak-tightness of the primary circuit and components of both the nuclear and conventional islands and to clean the main circulation pipes.
Subsequent hot functional tests will involve increasing the temperature of the reactor coolant system to ensure that coolant circuits and safety systems are operating as intended. Before operation, Tianwan 8 will also undergo containment pressure testing, fuel loading, criticality testing, grid connection, and post-grid connection power platform testing.
In 2018, Russia and China signed four agreements, including for the construction of two VVER-1200 reactors for Tianwan units 7&8. Construction of unit 7 began in May 2021, and unit 8 in February 2022. Tianwan 7 is scheduled to be commissioned in 2026 and Tianwan 8 in 2027. Tianwan 1-4, with VVER-1000 reactors, commissioned between 2007 and 2018, are already in operation. Units 5&6 with Chinese ACPR-1000s were commissioned in 2020 and 2021.
Tianwan NPP is owned and operated by the Jiangsu Nuclear Power Corporation, whose shareholders are CNNC (50%), China Power Investment Corporation (30%) and Jiangsu Guoxin Group (20%).
