Grid Connection for China’s Tianwan‑6

WNISR, 13 May 2021

The Tianwan-6 reactor was connected to the grid on 11 May 2021.

Photo: Tianwan Units 5 and 6.

Located on the Yellow Sea coast of Jiangsu province, in eastern China, the reactor was built by the China National Nuclear Corporation (CNNC). Tianwan-6 has been under construction since 7 September 2016. Unit-5 was connected to the grid on 8 August 2020. Both units are of the ACPR-1000 design, a more advanced version of China General Nuclear Corporation’s (CGN) Generation II CPR-1000 and the CNNC’s ACP-1000 design. Tianwan Units 1-4 are Russian-origin VVER-1000 design. The Tianwan plant is owned and operated by Jiangsu Nuclear Power Corporation, a joint venture between CNNC (50%), China Power Investment Corporation (30%) and Jiangsu Guoxin Group (20%). In April 2021, China’s state council approved construction start of Tianwan-7 and -8, both of which will be Russian supplied VVER1200 design.

CGN stated that the ACPR contains at least ten design improvements over the CPR-1000, including a double containment and core catcher, making them a Gen-III design. However, questions remain as to the safety revisions incorporated into the ACPR-1000, the qualification of the design by Chinese regulators and how they compare with their international counterparts.

Design work on the ACPR-1000 began in 2009, prior to the Fukushima events. In mid-November 2011, CGN revealed the design of the ACPR-1000, including the claim that it had taken into account the “lessons of the Fukushima accident”. That affirmation appears surprising given that it was pronounced only eight months after the dramatic events started unfolding in Japan. Other countries, e.g. France, ten years later, still struggle with the implementation of backfitting measures decided after 3/11. Further, the ACPR-1000 is reported to be in compliance with the domestic Code of Safety of Nuclear Power Plant Design, HAF102, which dates from 2004.

The International Atomic Energy Agency (IAEA) was requested to conduct a Generic Reactor Safety (GRS) review of the ACPR-1000 design-concept. This was completed in May 2013, but the results have not been published.

With grid connection of Tianwan-6, there are now 51 operating units in China, with 17 reactors remaining under construction, two of which are ACPR-1000 design. Worldwide, this brings the totals to 415 operating units and 50 reactors under construction.