Major repair work on the first phase of the Qinshan nuclear power plant, which began operation in 1991 as China's first nuclear power plant, was completed on January 13, 2008. The overhaul has improved the reliability and safety of the reactor and given the operators experience for running, repairing and upgrading other nuclear power plants in China, said He Xiaojian, General Manager of Qinshan Nuclear Power Co.

The 300,000-kilowatt pressurized water reactor generating unit of the plant was disengaged from the East China power grid for a fuel change and technical overhaul on October 28, 2007. During the 76 days, more than 7,200 overhaul projects were completed, including 37 major technical projects.

"This was the most sophisticated overhaul for the plant since it was put into operation," said Ouyang Yu, Designer-in-Chief of Qinshan nuclear power plant.

Two pressurized water reactors--the application of the most-sophisticated and widely-accepted nuclear power technology in the world--were installed at Fangjiashan, Haiyan, on the northern coast of Hangzhou Bay, Zhejiang Province. Each generating unit has an installed capacity of 1 million kilowatts.

"The expansion will be conducive to the sustainable development of the Qinshan nuclear power plant and will enable the plant to provide the Yangtze River Delta with more nuclear power," said Xu Pengfei, Vice General Manager of Qinshan Nuclear Power Co.

Replacement of the reactor pressure vessel head and digital upgrades of the protection system are the most important upgrade projects. The newly adopted reactor pressure vessel head is made of alloy materials with better performance, better pressure resistance and corrosion resistance, therefore better securing safe operation of the reactor. According to Ouyang, this is a preventive replacement based on experience of other nuclear power plants in the United States, France and Japan.

"After digital upgrading, the protection system will provide a more stable and more reliable 'nervous system' for the nuclear power plant," said Jiang Zuyue, Vice General Manager of Qinshan Nuclear Power Co. and in charge of the digital upgrading project.

According to Jiang, the protection system of Qinshan nuclear power plant used to adopt analogue signal. This time, digital upgrades were carried out according to state regulations and the latest standards.

The Qinshan complex has three sectors, each featuring different types of reactors, some of which were from domestic suppliers and some from foreign manufacturers. The first phase of Qinshan nuclear power plant is located at Haiyan of Zhejiang. It was the first nuclear power plant on the Chinese mainland, designed and built independently by domestic engineers. Construction of the plant began in 1985. It was built with a 300,000-kw prototype reactor with a designed lifespan of 30 years and began generating power in 1991.

As a nuclear power plant with a prototype reactor, the performance of Qinshan nuclear power plant is lower than nuclear power plants with commercial reactors. Every year, Qinshan nuclear power plant invests millions of yuan in technical innovation and has completed more than 1,900 innovation projects altogether.

As for the 30-year lifespan for the Qinshan nuclear power plant, Ouyang thinks that this is a prudent target and actually the designed lifespan should be 40 years. In his opinion, years of continuous technical innovation have improved the overall performance of the complex, which will help prolong the lifespan of the nuclear power plant.

Before the latest overhaul, the best record Qinshan nuclear power plant held was three fuel cycles of safe operation. In 2006, among the 265 pressurized water reactor units in the database of the World Association of Nuclear Operators worldwide, Qinshan nuclear power plant had six indicators of the total nine indicators of comprehensive performance reaching the advanced level and two indicators reaching the middle level.

Construction and operation of Qinshan nuclear power plant has greatly improved China's capability of independent development of nuclear power and China National Nuclear Power Corp. has subsequently developed the CNP300 brand with independent intellectual property rights.

Moreover, through constant upgrading and innovation, Qinshan nuclear power plant also creates economic benefits. From December 1991 to October 2007, it generated 31 billion kw/h of electricity and produced 9.6 billion yuan ($1.33 billion) in revenue and paid 1.8 billion yuan ($250 million) in tax.

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

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