The deformation occurred last Saturday when the flood from western provinces including Sichuan and Chongqing along the upper reaches of the Yangtze River peaked at a record-setting 61,000 cubic meters per second, according to China Three Gorges Corporation, a state-owned enterprise that manages the dam and the sprawling power plant underneath it.
The company noted that parts of the dam had “deformed slightly,” displacing some external structures, and seepage into the main outlet walls had also been reported throughout the 18 hours on Saturday and Sunday when water was discharged though its outlets.
But the problem of water seeping out did not last long, as the dam reportedly deployed floodgates to hold as much water as possible in its 39.3 billion-cubic-meter reservoir to shield the cities downstream from the biggest Yangtze deluge so far this year.
Meanwhile, Wang Hao, a member of the Chinese Academy of Engineering and an authority on hydraulics who sits on the Ministry of Water Resources’ Yangtze River Administration Commission, has also assured that the dam is sound enough to withstand the impact from floods twice the mass flow rate recorded on Saturday.
It is still raining in southwest China and that means the dam will be letting out more water to control the level behind the wall. Therefore, it is unlikely to be able to curtail the risk of flooding downriver.
This article from global policyjournal.com, from 2017, focusing on the development of nuclear power plants along the Yangtze may be of interest. Here is a section:
Beijing has released plans for a sizeable network of inland plants, mostly concentrated in central China along the Yangtze. Hubei and Hunan will be home to the most reactors outside the coast, with plans also for Jiangxi, Anhui, Henan, Sichuan, Chongqing, Guizhou and northern Guangdong. The principal problem facing inland nuclear is the high water demand of reactors — hence locating them along the Yangtze, which provides an inland water source. Traditional coastal nuclear powerhouses Guangdong and Zhejiang will massively ramp up capacity too. Guangdong is to get nine new nuclear sites with 28 reactors totalling 36,000 MWe. Zhejiang will add 15,000 megawatts (MW) to its existing 6,141 to remain the heartbeat of the Yangtze Delta. And the Bohai Bay industrial cluster of Liaoning-Hebei-Shandong is to become the third coastal civil nuclear hub, with Shandong moving from no nuclear presence to over 20,000 MW.
The greatest, and largely unquantifiable risk, is from a nuclear power station succumbing to flooding. Efforts to secure plants have been made over the last couple of years but this is a story that needs to be monitored closely.