The Republic of Korea (ROK) has no nuclear weapons program or capability and an unsanctioned uranium enrichment experiment four years ago was a by-product of tests to separate materials using a laser, the government said on Friday.

Oh Joon, director-general for international organizations at the ROK Foreign Ministry, said the enrichment equipment had been dismantled a few months after the single experiment aimed at separating uranium.

"This was an isolated case," he said, adding that the ROK believed the disclosure would have no impact on international efforts to end the North's own nuclear weapons ambitions.

"Do we have nuclear weapons capability? We don't," said Oh. Neither did Seoul have a nuclear weapons research program or enrichment program.

Oh said the ROK government scientists' enrichment experiment was fundamentally different to other countries' violations of the nuclear Non-proliferation Treaty (NPT) and came to light when a scientist approached the government recently.

"I wouldn't call them rogue scientists," he said.

It was unclear whether the scientists involved would face prosecution or sanctions, he said. The research center came into the spotlight because it was included in an additional protocol the ROK signed to the Non-Proliferation Treaty.

But the main opposition Grand National Party (GNP) questioned the official line that the production of a minute quantity of enriched uranium that some Western diplomats said was almost pure enough for an atomic bomb was just an experiment.

Oh said the enrichment was not as pure as had been reported but declined to put a figure on it or to say whether weapons-grade material had been produced. The government first disclosed the news of the experiment on Thursday.

UN nuclear inspectors completed field work on Friday on Seoul's declaration.

Inspectors leave site

The inspectors dodged reporters to leave the nuclear research center in Taejon, about 160 kilometers south of the capital. The International Atomic Energy Agency (IAEA) officials made a week-long inspection and were due to return to the UN nuclear watchdog's headquarters in Vienna on Saturday, officials said.

Chun Yu-ok, spokeswoman for the opposition GNP, said the experiments may have violated a key agreement with Pyongyang to keep the peninsula free of nuclear weapons. "Nobody will accept the explanation that scientists enriched uranium simply as an experiment," she said.

Western diplomats said that the experiments conducted by scientists at a government laboratory had produced uranium "very close" to the threshold for weapons-grade material. They added that the enrichment clearly amounted to a violation of the NPT.

But the head of the Korea Atomic Energy Research Institute in Taejon, the lab involved in the controversy, said the material extracted could not have been intended for weapons.

"I can see why there would be that suspicion. But what can you do with such a small amount?" Chang In-soon told KBS radio.

Japan, a participant in the six-party Korean Peninsula nuclear talks, cautiously reserved judgment on the disclosure, saying Tokyo did not believe Seoul was attempting to build nuclear arms.

"But if it is true that substances which must be controlled strictly under the IAEA had slipped by, then it is regrettable," top Tokyo spokesman Chief Cabinet Secretary Hiroyuki Hosoda said.

Washington, a key partner in the six-party talks, urged Seoul to ensure no enrichment activity remained in place.

(China Daily September 4, 2004)