Cold functional tests are carried out to confirm whether safety systems are properly installed and ready to operate in a cold conditions. They are the first comprehensives tests to check the performance of the entire reactor.
The main purpose of the tests is to verify the leak-tightness of the primary circuit and components such as pressure vessels, pipelines and valves of both the nuclear and conventional islands, and to clean the main circulation pipes.
Tianwan-6 is a domestically developed CNP1000 design. It is seen as a Generation II+ design and a precursor to Generation III designs.
Another unit of the same design, Tianwan-5, began commercial operation in September.
CNNC said Tianwan-6 is scheduled to enter commercial operation by the end of 2021, making it China’s 50th Commercial nuclear reactor. There are 11 units under construction in China.
There are also four Russia-procured VVER-1000 nuclear units in commercial operation at Tianwan.
According to the International Atomic Energy Agency, China’s fleet of reactors produced 4.9% of the country’s electricity in 2019.