Hot testing began on 28 November at unit 6 of China’s Tianwan NPP in Jiangsu, China Nuclear Engineering and Construction Corporation (CNECC) said.
The tests simulate the temperatures and pressures, which the reactor systems will have to withstand during normal operation. They verify that the nuclear island and conventional equipment and systems meet design requirements.
Cold functional tests, which were completed at Tianwan 6 on 4 October, confirm whether components and systems important to safety are properly installed and verify the leak-tightness of the primary circuit.
The commissioning Tianwan 6 is scheduled for the end of 2021.
CNECC, a subsidiary of China National Nuclear Corporation (CNNC), said the tests were a "dress rehearsal" before loading nuclear fuel and start-up of the reactor.
Tianwan 5&6 are both equipped with ACPR1000 reactors. First concrete was poured for unit 5 in December 2015, and for unit 6 in September 2016. Tianwan 5 began commercial operation last September. Tianwan 1-4, which began commercial operation between June 2007 and December 2018, were built by Rosatom and have VVER-1000 reactors designed by OKB Gidropress.
Units 7&8, which will also be built by Rosatom under a general contract which was signed in March 2020, will have VVER-1200 reactors. When all eight units are operational, Tianwan NPP will become the world’s largest NPP with a total generating capacity of about 8100 MWe. Tianwan NPP is owned and operated by Jiangsu Nuclear Power Corporation, a joint venture of CNNC (50%), China Power Investment Corporation (30%) and Jiangsu Guoxin Group (20%).