SOUTH KOREA: South Korea enriched a tiny amount of uranium in 2000 to a level close to what would be usable in an atomic weapon, the UN nuclear watchdog confirmed in a confidential report yesterday.
The president of the Korean Atomic Energy Research Institute in Taejon, South Korea - a senior government scientist - had authorised the experiments with the uranium and knew about the work with plutonium, a senior diplomat close to the International Atomic Energy Agency (IAEA) also said.
South Korea's government has denied knowing of plutonium and uranium experiments.
"Although the quantities of nuclear material involved have not been significant, the nature of the activities - uranium enrichment and plutonium separation - and the failures by [ South Korea] to report these activities in a timely matter . . . is a matter of serious concern," said the report.
"The agency is continuing the process of verifying the correctness and completeness of [ Seoul's] declarations."
The agency also said South Korean scientists had conducted experiments and later published papers on an experimental form of enriching uranium - chemical enrichment - but had failed to declare this work from 1979 to 1981 to the UN as required.
The South Korean scientists had imported some nuclear material and equipment from abroad, the report said, without naming the countries involved.
South Korea's concealment of its plutonium and uranium experiments was a violation of Seoul's obligations under the nuclear Non-Proliferation Treaty, which could require the IAEA board of governors to refer the matter to the UN Security Council, some diplomats in Vienna say.
Seoul has lobbied the Vienna-based IAEA to persuade its board not to refer it to the Security Council.
However, diplomats say Washington believes the council should pursue the issue as a precedent for similar violations by Iran.
The IAEA praised South Korea for co-operating, but said it still needed detailed documentation of the uranium enrichment and plutonium separation activities to finish its investigation.
South Korea had, however, refused repeated requests to take samples at some of its nuclear facilities, the IAEA said.
Seoul did not acknowledge its plutonium separation experiment, conducted in 1982 until March 2003, despite repeated questioning about plutonium particles found at sites.
The IAEA had found no signs that the South Korean experiments had gone beyond small-scale laboratory activities, the report said.
Seoul said it had no ambitions to develop nuclear arms and the IAEA said it had no reason to doubt this.
South Korea repeatedly denied any bomb-grade uranium had been found.
However, the IAEA confirmed that the scientists had enriched a small amount of uranium to 77 per cent uranium-235, the atom needed in large quantities in weapons.
Bombs with uranium fuel usually have cores enriched to at least 80 to 90 per cent.
Nevertheless, the average enrichment for the 10 experiments was only about 10 per cent uranium-235.
"[ South Korea] stated that only about 200 mg of enriched uranium were produced, following which the experiments were terminated," the report said.
The IAEA said only 0.7 grammes of plutonium were produced.
A country would need 15-25 kg of weapons-grade uranium or around 7-10 kg of plutonium for the core of a weapon.