The state has submitted a letter to the International Atomic Energy Agency (IAEA) ratifying an agreement to launch the world's first experimental fusion reactor.

Tang Guoqiang, China's permanent representative to the United Nations in Vienna, submitted the ratification letter signed by President Hu Jintao to IAEA chief Mohamed ElBaradei on Monday.

China will fulfill its obligations and contribute its share to the International Thermonuclear Experimental Reactor (ITER) project, Tang said.

ElBaradei praised China's research in the field of atomic fusion technology, saying the country's access to the ITER International Fusion Energy Organization is of great significance to the project.

China signed the Agreement of Joint Implementation of the ITER Project in November 2006 in France, along with the European Union, India, Japan, the Republic of Korea, Russia and the United States.

The first ITER site will be built in Cadarache, France.

The 11-billion-euro ($15.5 billion) ITER project, aimed at developing sustainable energy, is the largest ever international scientific research program.

More than a dozen Chinese scientists and managers are already working at Cadarache and more will soon join them, said Pan Chuanhong, a leading scientist of the ITER China program and president of the Southwest Physics Research Institute affiliated to China National Nuclear Corporation.

"If nothing changes, humanity will consume most of the fossil fuel resources accumulated over hundreds of millions of years within less than 100 years," Pan told China Daily yesterday.

"The ITER project is the victory of the general interest of humanity," he said.

The 500MW fusion reactor will aim to turn deuterium extracted from seawater into fuel by mimicking the way the Sun produces energy: As two light atomic nuclei fuse together to form a heavier one, a huge amount of energy is released.

Fusion reactors will be vastly cleaner than existing fission nuclear reactors, and offer almost limitless supplies of energy, with 1 liter of deuterium producing the same amount of energy as 300 liters of petrol, the scientist said.