It is difficult to say whether the International Thermonuclear Experimental Reactor (ITER), originally scheduled to be completed in 2019, will be delayed，the project is a hard one, according to Chen Shaolian, director of the Eighth Research Institute of Nuclear Industry.

Chen said this at a forum held by Shanghai association for science and technology on August 23. Two Chinese research institutes participating in the project are making efforts, but the process is very difficult, he added. 

The project, known as the "artificial sun", is funded and run by seven member entities — China, the European Union, India, Japan, Russia, South Korea and the United States and has 35 participating countries. It is a big budget science project, second only to the International Space Station.

Data shows ITER is designed to produce approximately 500 MW of fusion power sustained for up to 1,000 seconds by the fusion of about 0.5 grams of deuterium/tritium mixture in its approximately 840-cubic meter reactor chamber.