South Korea conducted laser enrichment experiments in 2000, producing 200mg of enriched uranium in violation of its Non-Proliferation Treaty (NPT) commitments. The lab-scale experiments came to light in the declarations made to the IAEA pursuant to the NPT Additional Protocol, which the country brought into force in February.

IAEA director general Mohamed ElBaradei told the agency’s board of governors on 13 September that the failure of the South Korean government to report the work was “a matter of serious concern.”

An inspection team was sent to the Korean Atomic Energy Research Institute and other facilities where uranium conversion experiments were conducted during the 1980s. ElBaradei said: “One of these conversion activities, which took place at three facilities that had not been declared to the agency, involved the production of about 150kg of natural uranium metal, a small amount of which was later used in atomic vapour laser isotope separation (AVLIS) experiments.” The team was given full access to facilities and the freedom to document their findings and place seals on equipment.

ElBaradei is set to report on the matter in time for the November meeting of the IAEA board of governors.

South Korean authorities have declared that the tests were performed without the knowledge or authorisation of the government: “we should have reported that we were using nuclear materials for the test but we did not know about the experiment at the time,” a foreign ministry official is quoted as saying.