SKorea detects radioactive silver

The Korea Institute of Nuclear Safety (KINS) said minuscule traces of radioactive silver had been detected above the central city of Daejeon and the southeastern city of Daegu.

"In general, radioactive silver can be found when nuclear power plants develop serious incidents," KINS said in a statement.

During the Chernobyl nuclear disaster, the same volatile product was found, a KINS official told AFP, in reference to the accident that hit the Soviet-built reactor in Ukraine in 1986.

"This material can be found when containers holding nuclear fuel rods are damaged," he said.

But KINS stressed the levels of radioactive silver were 3,700 times lower than the radiation given off by one chest X-ray and posed little health hazard.

Traces of other radioactive materials including iodine were also detected in the atmosphere in Seoul and across the country this week, though the amount was so small that there was no immediate risk to health or the environment, KINS said.

South Korea has stepped up monitoring of radiation levels following the crisis at Japan's Fukushima nuclear plant which was crippled by the March 11 quake and tsunami.