Construction began in October 1999, and was the first instance of civilian nuclear cooperation between Russia and China.

When all the units are complete, Tianwan will be the world's largest nuclear power plant, with generation capacity exceeding 9,000 MWe.

Also there's a revolutionary security improvement called the trap, which prevents any leakage of nuclear fuel in the event of a breakdownMost units use VVER pressurized water reactor (PWR) technology supplied from Russia.

Units 7 and 8 will use the updated VVER-1200 design capable of approximately 1.2 GW, with twice the expected operational lifetime and a 2/3-slower refueling cadence.

[3][4] The reactor units are housed in a confinement shell that can withstand a 20-ton aircraft crash, and have special earthquake protections.

[citation needed] Other important safety features include an emergency "core catcher" in case of meltdown.

[5][13] The following January, ASE transferred control of units 3 and 4 to Jiangsu Nuclear Power Corporation.