[JURIST] The International Atomic Energy Agency has reported that South Korea conducted illegal nuclear tests in the 1980s and 2000, in which it secretly extracted or enriched small amounts of plutonium and uranium. Although the tests did not produce enough uranium for a weapon and South Korea has repeatedly stressed it does not intend to build one, IAEA chief Mohammad ElBaradei said the tests were a serious concern. The revelation could cloud international efforts to negotiate with North Korea, which is widely suspected of already having produced several nuclear bombs. South Korea's tests may have violated the nuclear Non-Proliferation Treaty, which could result in referral to the UN Security Council. From South Korea, JoongAng Daily National has more on officials' efforts to downplay the IAEA report. BBC News has more.