The news came a week after a similar-sized plant started construction in south-eastern Fujian province, as China appears to be accelerating construction of nuclear power stations after nearly half of the nation was hit by blackouts in late January during the coldest winter in decades.

Builders will dig a hole 12 metres deep and over 20 metres in diameter for the first generating unit, with 1.25 gigawatts capacity in Sanmen city, Xinhua reported late on Tuesday.

Last July, Westinghouse - owned by Japan's Toshiba - signed a multi-billion-dollar deal with Chinese partners to build four nuclear reactors, two in Sanmen and another two in Haiyang city in eastern Shandong province.

Xinhua said Sanmen Nuclear Power, operator of of the Sanmen plant, will eventually build six generating units of the same capacity, without elaborating if such expansion plans have won state approval or giving a timeline for completion of all the units.

China, the world's second-largest power market, currently has 11 working reactors with 9.07 GW of total installed capacity, which Beijing plans to expand to 40 GW by 2020.

In 2007, nuclear plants generated 62 billion kilowatt hours of electricity, up 16 per cent from a year ago, but only accounting for 2 per cent of the nation's total, official data has shown, far behind the three-quarters in France and one quarter in Japan.

China generates about 80 per cent its power from coal. -- REUTERS