BEIJING - China's operating nuclear power units enjoy a relatively good safety record, and the quality of the units under construction has been well controlled, said the head of China's nuclear watchdog on Wednesday.

Li Ganjie, vice minister of environmental protection and head of the National Nuclear Safety Administration, told a press conference that no serious operational incidents have occurred in the 30 years since China launched its first nuclear power plant.

In 1984, the country began to build its first nuclear power plant, the Qinshan Nuclear Power Plant, in the eastern province of Zhejiang. The domestically designed facility was put into operation in 1991.

China now has 19 operating nuclear power units and 29 units under construction, ranking it as one of the biggest nuclear power nations in terms of the number of such facilities, according to Li.

"China's nuclear power development over 30 years has generally been smooth, healthy and safe," he said.

However, Li said maintaining safety in this area is a challenging task, as it concerns state security. He admitted that loopholes and problems, both in supervision and the whole nuclear industry, still exist.

The vice minister vowed to strengthen supervision with a well-established institution, a perfected legal system, as well as more capable personnel.