SEOUL, South Korea - The United Nations nuclear watchdog agency is investigating an incident in which South Korean scientists at a large government research institute secretly experimented with highly enriched uranium, nuclear material that could be used in making a bomb.
Although only a minuscule amount of uranium was involved, the revelation could prove highly embarrassing to South Korea and highly awkward for the United States as it wrestles with the nuclear ambitions of North Korea and Iran.
The South Korean government said yesterday that it had reported the experiment voluntarily to the International Atomic Energy Agency, or IAEA, and would ensure that it did not happen again.
The Vienna, Austria-based nuclear watchdog took the information seriously enough to immediately dispatch a seven-member inspection team to South Korea on Sunday. The team is examining the experiments to determine the extent of South Korea's enrichment effort and the sources of the material and components used in the test.
South Korea is a signatory to the Nuclear Nonproliferation Treaty, which requires countries to notify the IAEA of any work on enriching uranium, which can produce the key ingredient in nuclear bombs.
The experiment took place at the Korea Atomic Energy Research Institute in Taejon over two months in 2000, and immediately afterward the uranium was isolated and the equipment dismantled, according to the Seoul government.
"This is very much an isolated case. We do not have any enrichment program or reprocessing program," said Oh Joon, a Foreign Ministry official who deals with the U.N. nuclear agency. "There is no comparison to any other case of noncompliance by some countries, and we do not expect it to have an effect on our efforts to resolve the North Korean nuclear issue."
A Western diplomat familiar with the investigation said the uranium in question, although small in quantity, was enriched nearly to weapons grade.
"They should have told [the nuclear watchdog agency] that they were doing this at the time," said the diplomat, who requested anonymity because of the sensitivity of the issue. "The IAEA was asking questions for a long time about this site. They probably realized they had to come forward before IAEA inspectors discovered it during an inspection."
In Washington, State Department spokesman Richard Boucher said that the experiment "should not have occurred" but added that South Korea had reported the activity voluntarily.
Any controversy over South Korea's nuclear program could complicate the U.S.-led effort to halt North Korea's nuclear program.
Critics could accuse the Bush administration of applying a double standard by threatening to bring Iran and North Korea - but not its ally, South Korea - before the U.N. Security Council. North Korea, which the United States alleges has a secret program to enrich uranium, could use the South Korean case as an excuse for its own actions.
The Los Angeles Times is a Tribune Publishing newspaper.