HANGZHOU -- Workers on Friday hoisted a 170-ton dome into place over the underground workshop that will house a third reactor at the second phase of the Qinshan nuclear power complex, the first commercial nuclear power facility in China.

That step cleared the way for installation of a 650,000 kw pressurized water reactor at the nuclear complex, which is located in Haiyan, on the northern coast of Hangzhou Bay, Zhejiang Province, not far from Shanghai. The Qinshan complex has three phases, each featuring different types of reactor, some of which were from domestic suppliers and some from foreign manufacturers.

Construction of another underground workshop for a fourth generating unit is also under way, according to Yang Lanhe, General Manager of Nuclear Power Qinshan Joint Venture Co. Ltd, investor of the second phase of the Qinshan complex.

The first phase of the Qinshan facility was also the first nuclear power plant on the mainland built independently by domestic engineers. Construction on the facility began in 1985. The first phase featured a 300,000 kilowatt  prototype reactor with a lifespan of 30 years, which went online in 1991.

The first phase of the plant, which suspended power generation for a fuel change starting on October 28, is to resume operation in January. The complex will see the addition of two more pressurized reactors, each of which is to have an installed capacity of 1 million kilowatts.

The first phase has so far generated 31 billion kwh of electricity and produced 9.6 billion yuan ($1.28 billion) in revenue and paid 1.8 billion yuan in tax.

The plant also has second and third phases. The second phase involves the plant where work was done on Friday. It has two functioning 650,000-kw units that began generating power in 2002 and 2004, respectively. The expansion of phase two will involve the installation of two 650,000-kw pressurized reactors. The expansion program began in April 2006. It will be fully completed and start power generation in late 2011.

Through December 17, the second phase of the Qinshan nuclear plant had generated 8.5 billion kwh of electricity for 2007. When all four units are in operation, the second phase will be able to produce 18-20 billion kwh of electricity a year.

The third phase houses two Canadian CANDU heavy-water reactors.