Investment in the second two-reactor stage of the Tianwan nuclear plant may equal the first phase, a source close to the project has revealed.

The first phase also involved two reactors, each with the capacity of 1,060 megawatts (mW).

Tianwan nuclear power plant in Lianyungang, Jiangsu province. [File]

With an investment of 26.5 billion yuan ($3.79 billion), it is by now the largest cooperative project between China and Russia.

A cooperation project on nuclear power may be signed by the two nations during Dmitry Medvedev's visit, said the source, who wished to remain anonymous.

Both parties signed a framework agreement for the Tianwan nuclear power plant phase II last November, he said.

Located in Lianyungang in east China's Jiangsu province, the Tianwan first reactor began operation in May 2007 and was followed three months later by the other.

The two reactors generated 10.02 billion kilowatt-hours (kwh) of electricity last year, double the original annual target.

Tianwan has now become an important nuclear power base in China, along with Qinshan in Zhejiang and Daya Bay in Guangdong.

The Tianwan site was designed to host eight nuclear reactors with a combined capacity of 8,000 mW.

Plans for the other four reactors are still in the preliminary stage, said a source with Jiangsu Nuclear Power Corp, operator of the project.

Decisions have not yet been made about the technology to be used, according to the source.

China is now developing third-generation nuclear power technology.

Last year the country finalized an agreement with US-based Westinghouse to use AP1000 technology to build four nuclear reactors, two in Zhejiang and another two in Shandong.

China also signed an 8-billion-euro agreement with French nuclear company Areva for two third-generation European pressurized reactors in Taishan in Guangdong province.

China now has 11 nuclear generating units in operation with a total capacity of 9,080 mW.

Three use domestic technology, two are Russian designed, while four others are based on French blueprints and two more on Canadian models.

These projects generated 62.6 billion kwh of nuclear power in 2007, up 14.1 percent year-on-year, according to the China Electricity Council.

In 2005, China planned to increase its nuclear power capacity to 40 gigawatts by 2020, when it will account for 4 percent of the nation's total power generation.

Editor: Yan