SEOUL — A top South Korean scientist acknowledged Saturday that an unauthorized experiment to enrich uranium was conducted in 2000 but said the amount in question was "so small it's almost invisible."
The experiment, consisting of three or four tests, was conducted in January and February 2000 at the government-affiliated Korea Atomic Energy Research Institute, said facility President Chang In Soon.
"You often don't get the desired result in the first test," Chang said. "In the viewpoints of scientists, whether you had one test or 10 tests doesn't make a big difference in this case."
He said scientists enriched uranium to 10% during the tests -- much lower than weapons-grade, which requires enrichment of more than 90%. Enriched uranium can also be used as fuel for nuclear power plants.
Chang said the amount enriched was "so small it's almost invisible."
"It's absurd for some people to speculate about weapons-grade over this," he said. "I don't think any of the uranium was enriched to weapons-grade."
He said only 0.01 ounce of uranium was produced in the tests.
Several pounds of highly enriched uranium are needed to build a bomb, experts say.
South Korea said last week that it had voluntarily reported the experiment to the International Atomic Energy Agency and would ensure that it didn't happen again.
But such a test could provide North Korea with a pretext to further delay stalled talks on dismantling its nuclear programs.
The Vienna-based IAEA sent an inspection team to South Korea last week to determine the extent of the enrichment effort.
South Korea is a signatory to the Nuclear Nonproliferation Treaty, which requires nations to notify the IAEA of any work on enriching uranium.