The Science and Technology Ministry has confirmed that no traces of radioactive pollution have been found in South Korea following North Korea's reported nuclear test on Monday.

Citing radiation levels tested nationwide in the three days since, the ministry said levels were normal in Seoul at no more than 12-point-one-nine micro Roentgens and 12-point-two-three micro Roengtens or below in the east coast city of Gangneung.

The ministry said while it has detected no pollution yet, it's still difficult to confirm whether a test was conducted.

Noting that ground water flows from higher to lower altitudes, the ministry said that it's impossible for North Korean water to move southward and thus there's no chance of the South's ground water getting contaminated by radiation.