SINGAPORE: China is set to overtake the United States to have the world's largest nuclear capacity over the next 10 to 15 years as it races to build new reactors to combat pollution, the World Nuclear Association (WNA) said on Tuesday.

It will overtake France to have the second-highest number of nuclear reactors by 2020, Agneta Rising, the WNA's director general, said at an annual energy conference in Singapore.

"For China, the air pollution is a major driver," she said on the sidelines of the Singapore International Energy Week.

In Asia, 134 operable reactors generated 400 terawatt-hours of electricity in 2015, making up 16 percent of global nuclear generation, the WNA said in a report released on Tuesday.

Another 39 reactors comprising 47.4 gigawatts (GW) are currently under construction in Asia, which comprises nearly two-thirds of global reactor construction. China makes up the bulk with 20 reactors under construction.

"There is history in the region, where you have high-skilled people with very good university education and they have been working on research reactors ... so I think there is basis of knowledge," Rising said. "The big driver (in Asia) is to have electricity for people."

There are also plans for more than 50 reactors comprising more than 50,000 megawatts (MW) in nine new countries in the region, with most planning to have their first nuclear reactors enter operation before 2030, the WNA said.

Bangladesh looks likely to have the first reactor online among these new countries in six years, Rising said, which would also be the first for the country.

However, many southeast Asian countries are pushing back the timeline for new reactors to come online, including Malaysia and Thailand.

"It's a combination of cost as it's a large infrastructure and also there needs to be more groups involved in discussions and have transparency in plans," she said.

New reactor construction is mostly led by industrialising countries which have enjoyed high levels of economic growth with an accompanying increase in energy demand, the WNA said in the report.

Four countries are expected to account for 70 percent of reactors commissioned in the period to 2030, which are China, Russia, India and South Korea.