Kang Rixin, who is also the party boss of China National Nuclear Corp (CNNC), is under investigation for "seriously violating discipline", Xinhua said on its website, citing officials from CPC's Central Committee for Discipline Inspection.
That terminology is usually used to indicate a corruption investigation.
As China's largest nuclear power developer and operator, CNNC oversees billions of dollars worth of planned new projects as China aggressively expands its nuclear power capacity. It has a Hong Kong-listed firm, CNNC International.
Kang has served as CNNC's general manager for almost six years.
A source close to CNNC was not aware of any potential impact on the construction of existing nuclear power projects, which includes the Sanmen Nuclear Power plant in eastern Zhejiang province that will adopt technologies imported from Westinghouse, a U.S. company owned by Japan's Toshiba Corp.
CNNC's other nuclear power projects under construction include an expansion of the Qinshan nuclear power plant in Zhejiang and a new plant in Fujian province.
It is also considering adding more reactors at the Tianwan nuclear power plant in eastern Jiangsu province that is based on Russian technology.
