China appointed a new chief for its top nuclear firm, China National Nuclear Corp (CNNC), after its former general manager was dismissed for seriously violating discipline, the official Xinhua news agency said on Friday.

Sun Qin, formerly CNNC's deputy general manager before he became deputy head of the National Energy Administration (NEA), will replace Kang Rixin, former chief of the nuclear company, who is now under investigation.

China has been aggressively expanding its nuclear capacity as part of efforts to increase cleaner energy supplies and reduce dependence on polluting coal.

The world's No.2 energy user, which started building five nuclear plants this year, plans to double its target for installed nuclear power generating capacity to 86 gigawatts (GW) by 2020 from the previous goal of 40 GW.

CNNC, parent of the Hong Kong-listed CNNC International, is China's largest nuclear power developer and operator.

A slew of top Chinese officials and executives have been felled by economic crimes recently. Li Peiying, once head of the holding company that runs Beijing airport, was executed early this month after being convicted of taking bribes and embezzlement.

Chen Tonghai, ex-chairman of top Asian refiner Sinopec Corp, got a suspended death sentence last month, also for taking bribes.

China Energy