Hot functional testing of the Karachi 2 reactor in Pakistan was completed on 4 September, China National Nuclear Corporation (CNNC) announced today. The Chinese-designed Hualong One reactor is scheduled for commercial operation next year.

Karachi 2 and 3 are the first export of China's Hualong One design, promoted on the international market as the HPR1000.

Hot 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.

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 Karachi 2 in December. The main purpose of those tests was to verify the leak-tightness of the primary circuit.

Construction of unit 2 began in 2015 and unit 3 in 2016. Installation of the reactor internals of Karachi 2 was completed in January 2019, while installation of unit 3's was completed in April this year. The units are scheduled for commercial operation in 2021 and 2022, respectively.

Four Hualong One units - Fuqing 5 and 6 in Fujian province and Fangchenggang units 3 and 4 in Guangxi province - are expected to be connected to the Chinese by the end of 2022. The process of loading fuel assemblies into the core of Fuqing 5 began on 4 September and the unit is expected to start up later this year, with Fuqing 6 following next year. CNNC has also started construction of two Hualong units at the Zhangzhou plant in Fujian province, plus the first of two units at Taipingling in Guangdong.