Workers have completed the welding of the main circulation pipeline for the Tianwan-7 nuclear power plant under construction in Jiangsu province, eastern China, Russia’s state-owned nuclear corporation Rosatom said.

Tianwan-7 is a Russia-supplied 1,200-MW Generation III+ pressurised water reactor (PWR) unit, construction of which began in May 2021.

The main pipeline connects the reactor pressure vessel (RPV) with the steam generators and the reactor coolant pumps and is an integral part of a pressurised water reactor system.

Rosatom said welding of the pipeline paves the way for the flushing of reactor systems and preparations for the loading of dummy fuel assemblies for further testing.

According to previous reports, the RPV for Tianwan-7 was installed in Oct 2023.

There are two Russian VVER-1200 PWR units being built at Tianwan. Construction of the identical Tianwan-8 started in February 2022.

The Tianwan station has another six PWR units in commercial operation. Units 1 to 4 were built by Russia using its VVER-1000 PWR technology. Units 5 and 6 are China’s indigenous CNP-1000 PWR design.