China's annual nuclear industry expo opened in Beijing on Monday after a six-month delay due to the COVID-19 pandemic.  

One of several exhibits on display is the Hualong One, a third-generation power unit developed by Chinese companies that will soon be operational after five years of construction and test.  

Fan Li, one of its designers from China Nuclear Power Engineering, said the unit is ready for the state of "criticality," with fuel being completely loaded into a reactor core.  

"It's like the ignition process in a conventional thermal power plant. After this, the entire reactor will go into operation," he said. 

Another third-generation nuclear power technology called Guohe One is also on display after 12 years of research and development came to completion at the end of September.  

Liu Fei, deputy director general on nuclear energy safety and development from State Power Investment Corporation, said it promotes the upgrade of the entire nuclear industry in China. 

"Over 90 percent of Guohe One's equipment is domestically made, with all its key parts and materials being domestically designed and produced," Liu said. 

These third-generation units have multiple safety designs, like passive safety systems, which requires no operator actions to mitigate design-basis accidents, and thus will play important roles in generating power. 

One booth has been of particular interest at the expo, showcasing a model that derived from a large project undertaken by 35 countries, including China. The ITER, International Thermonuclear Experimental Reactor, based in the south of France is expected to launch operations in 2025. 

It will make fission-type nuclear meltdown or a runaway reaction impossible. The device started assembly in July and one Chinese company played a central role in the process.  

Luo Delong, director general of ITER China Domestic Agency under Chinese Ministry of Science and Technology said that China contributes through providing components, manufacturing and research. 

"After 2025, we hope we can finish the first installation phase and we start operations. And we will send our scientists to do the operations," Luo said. 

The nuclear technology has also played an important role in many other sectors, including medical treatment and even in combating the COVID-19 pandemic through sterilizing medical equipment.

This technology is expected to bring more advancements under strict supervision.