China's endeavor to increase the use of clean energy got a big boost on Wednesday after an experimental fast reactor using the mostly homegrown fourth-generation nuclear technology reached the critical state.

Fast reactors that run on the fourth-generation technology differ from others in that they are able to utilize the fuel in a more optimal way so as to reduce the overall energy costs significantly.

The technology will also lift the uranium usage ratio to as high as 70 percent from existing 1 percent. In the long run, it will also considerably reduce the nation's reliance on foreign fuel imports.

"The fast reactor will extend China's utilization of proven and verified uranium resources to 1,000 years from less than 100 years through the existing pressurized water reactors," said Zhang Donghui, general manager of the fast reactor program.

The fast reactor program has been set up with a total investment of 2.5 billion yuan ($369 million) and China is the eighth country to successfully master the technology.

"This is a significant step in China's nuclear program," said Zhao Zhixiang, dean of China Institute of Atomic Energy.

Uranium prices have been firming up recently due to a surge in demand and a dwindling of global proven resources. Added to this is also the long gestation time for successfully mining uranium from new finds.

China currently produces around 750 tons of uranium. The demand-supply gap of uranium is expected to exceed 10,000 tons by 2015 and reach nearly 30,000 tons by 2030, according to Yan Qiang, a researcher with Chinese Academy of Geological Sciences.

With the bulk of the nuclear power likely to be used for meeting the nation's power needs, demand for the clean energy is also expected to surge, said Yan.

China plans to set up 60 new nuclear reactors and have a nuclear power productivity of around 75 million kilowatts by 2020. The country is also constructing 23 machine sets to harness nuclear power, the largest among the 57 such sets in the world.

The nation is likely to double its uranium purchases to around 5,000 metric tons this year to build stockpiles for new reactors, said Thomas Neff, a physicist and uranium-industry analyst at the Massachusetts Institute of Technology in Cambridge.

China Uranium Development Co Ltd recently acquired a majority stake in Australian miner Energy Metals Ltd.