North Korea unveils highly sophisticated nuclear facility

The US is trying to restart moribund nuclear disarmament talks over North Korea, after the Communist leadership there showed off a new and highly sophisticated uranium enrichment plant.

An American scientist who was taken to see the facility called it "stunning" and "astonishingly modern", casting doubt over the ability of UN sanctions to thwart or even slow down North Korea's nuclear ambitions.

Satellite photography is also showing new construction work at the Yongbyon site of the country's main nuclear reactor, work that the regime says is aimed at building a light-water reactor for generating electricity.

The US state department's special representative on North Korean policy flew to the region yesterday to have talks with some members of the so-called "six-party talks", whose negotiations on disarmament have been stalled for almost two years. Stephen Bosworth arrived in the South Korean capital, Seoul, to meet Kim Sung Hwan, the country's Foreign Minister.

As well as North and South Korea and the US, the group of six includes Japan, Russia and North Korea's main diplomatic backer, China.

The Stanford University professor Siegfried Hecker, a veteran nuclear scientist and former director of the US Los Alamos Nuclear Laboratory, was on a visit to Yongbyon two weeks ago when officials called him to see a secretly and rapidly built new enrichment facility. "Instead of seeing a few small cascades of centrifuges, which I believed to exist in North Korea, we saw a modern, clean centrifuge plant of more than a thousand centrifuges, all neatly aligned and plumbed below us," he wrote in a report.

He described the control room as "astonishingly modern" and on a par with "any modern American processing facility". Construction of the centrifuges began only in April 2009, the scientist was told. When international weapons inspectors were expelled from the country last year the plant did not exist.

North Korea has built a small number of nuclear weapons from plutonium but enriched uranium can be used for more powerful bombs.

Many questions are still unanswered about North Korea's nuclear programme, Professor Hecker wrote, including whether the North is really only pursuing nuclear electricity; how it got such sophisticated centrifuge technology; and why it is revealing the facilities now. "One thing is certain," he said. "These revelations will cause a political firestorm."

Kim Jong-Il, North Korea's leader, is "predictable in his unpredictability", the US chairman of the joint chiefs of staff, Admiral Mike Mullen, said in response to the latest disclosures. "It's North Korea continuing on a path which is destabilising for the region," he told CNN's State of the Nation. "It confirms or validates the concern we've had for years about their enriching uranium. All of this is consistent with belligerent behaviour."

The apparent sophistication of the facilities shown to Professor Hecker caused alarm in Washington. Its disclosure comes on the heels of new satellite photography which suggested that North Korea is making good on its promise last year to restore its Yongbyon reactor for making weapons-grade plutonium.