Cold hydrostatic testing started on 26 November at unit 3 of the Tianwan NPP in China's Jiangsu province, China Nuclear Industry 23 Construction Company Limited (CNI23) announced. China National Nuclear Corporation's (CNNC's) Tianwan 3 and 4 will be AES-91 VVER-1000 units designed by Gidropress and supplied by Russian state nuclear corporation Rosatom. Atomstroyexport is the main contractor, supplying the nuclear island. First concrete for unit 3 was poured in December 2012, while construction of unit 4 began in September 2013. Unit 3 is scheduled to begin operating in February 2018 and unit 4 in March 2019. Two similar reactors (units 1 and 2) began operating at the site in 2007. Tianwan NPP 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%).