VIENNA -- A U.S. institute tracking North Korea's nuclear weapons program says recent satellite photos show that Pyongyang is doubling the size of its uranium enrichment plant, jibing with the country's announced plans to expand technology that can be used both to create energy and the core of nuclear weapons.
The imagery comes from two sources, satellite companies Digital Globe and Astrium Geoinformation Services, and was seen by The Associated Press ahead of publication Wednesday by the Institute for Science and International Security. In an accompanying note, ISIS said the photos of the Nyongbyon nuclear complex show construction underway to "effectively double" the size of the enrichment hall.
That, said ISIS, would allow North Korea to also double the number of centrifuges now enriching uranium. Revealing the existence of a uranium enrichment program three years ago, Pyongyang said the plant contained 2,000 centrifuges -- machines that are linked up in series and spin uranium gas into material that can be used either to power reactors or arm nuclear weapons, depending on the degree of enrichment.
That means the 4,000 centrifuges that the space is apparently being expanded for could potentially make twice that amount, giving them the capacity to build as many as four bombs a year -- should the country decide to use them for that purpose.
The most recent satellite photo was taken July 28. ISIS says that measured against earlier images, it shows construction at the Nyongbyon site, including "the expansion of the gas centrifuge building" to twice its previous size.
The Washington-based think tank said the images indicate that work on the structure seems to have begun sometime in March. It cited a North Korean government announcement that came shortly afterward, revealing plans for "readjusting and restarting all the nuclear facilities in Nyongbyon, including [the] uranium enrichment plant."
Government offices in Pyongyang that could comment were shut for the day ahead of publication of the ISIS report. A North Korean diplomat with his country's mission to the United Nations in New York said he had no comment because he had not yet seen the report. He demanded anonymity because he was not authorized to speak publicly about his country's nuclear program.
Experts believe that the plant is meant primarily to provide fuel for the power-hungry country. But centrifuges producing such fuel can be reconfigured to make weapons-grade uranium. That has led to international concerns because of three nuclear weapon tests by the North Koreans -- the most recent in February -- and the country's stated intention to continue down the nuclear weapons path.
The first two tests are believed to have used plutonium, fissile material that also can be used in weapons. But experts and governments say that with its uranium enrichment program confirmed and operating, the third explosion may have used highly enriched uranium.
Meanwhile Wednesday, North Korea said it is lifting a ban on operations at a jointly run factory park shuttered since Pyongyang pulled out its 53,000 workers in April amid tensions with South Korea, and the rival neighbors agreed to meet next week for talks meant to restart the complex.
The agreement revives hope for resumption of production at the Kaesong complex, the last remaining symbol of inter-Korean cooperation from an earlier period of detente. The industrial park combined South Korean initiative, capital and technology with cheap North Korean labor. It was also a rare source of hard currency for North Korea.
James Hardy, Asia-Pacific editor of Jane's Defence Weekly, said the potential nuclear expansion will complicate any South Korean attempts to lower tensions with its northern neighbor. Tensions may also rise again this month, as South Korea and the United States are scheduled to begin a joint military exercise Aug. 19.