The first generator at the Ningde Nuclear Power Station in east China's Fujian Province went into operation on Thursday.
The generator has an installed capacity of 1.09 million kilowatts (kw), the same as the plant's other three generators, which are still under construction.
"The safety of the plant meets advanced international standards," said Huang Xiaohang, deputy general manager of Ningde Nuclear Power Co., Ltd.
Huang said natural disasters like earthquakes and tsunamis were taken into consideration when designing and locating the plant.
The operation of the plant's first generator will increase Fujian's usage of clean energy from 42.56 percent to 45.32 percent, according to Huang Wenying, deputy chief engineer of the State Grid's Fujian branch.
Fujian will transmit 3.6 billion kilowatt-hours (kwh) of electricity to other provinces this year.
The plant is co-funded and run by the Guangdong Nuclear Power Group, Datang International Power Generation Co., Ltd. and Fujian Energy Group Co., Ltd. Construction on the plant began in 2008.
According to a government white paper on energy released in October 2012, China has 15 nuclear power-generating units in operation with a total installed capacity of 12.54 gigawatts (GW), as well as 30 units currently under construction, which will add another 32.81 GW.
China will have the third-largest number of nuclear power-generating units in operation in the world by 2020 after the United States and France. The installed capacity of the units will amount to 58 GW by 2020, or less than 4 percent of China's total power-generating capacity.