ANKARA 

South Korea Tuesday said there has been no "meaningful" change in radioactive levels in the Yellow Sea following a report over North Korea's suspected discharge of wastewater from its uranium refining facility in the North Hwanghae province, local media reports said.

The clarification came days after Daily NK, a South Korean news outlet focusing on the North, reported that Pyongyang has been operating a uranium refining facility in Pyongsan County and begun directly dumping uranium waste into rivers flowing into South Korea.

South Korea's Unification Ministry said it has been closely monitoring North Korea's nuclear activity, including from the uranium refining plant in Pyongsan, and found no extraordinary change, Seoul-based Yonhap News reported.

"In regard to relevant agencies' regular measuring of radioactive levels in the Yellow Sea, there has been no meaningful change," an anonymous ministry official said.

"But as the issue is directly related to our people's health and safety and the environment, the ministry is in close talks with other agencies over how to respond to it," the official added.

Last month, a US-based monitoring program said that recent satellite imagery indicates the construction of a suspected uranium enrichment plant at North Korea's main nuclear complex in Yongbyon, north of the capital Pyongyang.