Construction sites. Flushing of the reactor safety systems began at China’s Tianwan Unit 7 being constructed with input from Rosatom. One of the most critical pre-commissioning operations, it serves to clean the circuit pipelines of the debris left after the installation and check the operation of pumps, instrumentation and controls, and safety systems. When completed, the flushing will be followed by the reactor assembly and other pre-commissioning operations, such as cold and hot functional tests and trial runs of the primary circuit systems. The Tianwan NPP is the largest Russia-China economic cooperation project. Construction of Tianwan Unit 7 and Unit 8 started in May 2021. The four earlier built power units with Russian-designed VVER-1000 reactors are in operation, supplying millions of kilowatts of electricity to the country’s power grid.