Satellite photos show expansion of suspected North Korean uranium enrichment site

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A suspected North Korean uranium enrichment facility that may have been toured by leader Kim Jong Un recently has grown significantly since construction was first spotted there in February, satellite imagery has revealed.

The Kangson facility, just outside of the capital Pyongyang, is being monitored by the International Atomic Energy Agency, or IAEA, for possible production of enriched uranium, which can be used for nuclear power generation – but is also a vital ingredient for an atomic bomb.

North Korea is extremely secretive about its nuclear program, and has not allowed IAEA inspectors back into the country after expelling them in 2009.

Based on its aerial observations, the IAEA said that in February, construction began on a new annex along the side of the main building of the Kangson complex.

That is corroborated by a satellite photo of the complex taken in February by Planet Labs, an U.S.-based private satellite imagery company, which shows the expansion work is visible.

In March, the construction site began to be covered with a blue roof, other satellite photos show. And in April, the entire construction site was covered with a blue roof. The images appear to show that construction was completed in May.

“The annex was externally complete by early-April 2024. In May 2024, a support building adjacent to the main building was renovated and expanded,” the IAEA report said.

Kim’s visit

North Korean state media reported on Kim’s visit to an unnamed “production base of weapons-grade nuclear materials” last week, saying that he expressed “great satisfaction” with the improved nuclear capabilities, which would help North Korea’s “revolutionary cause.”

One expert told RFA that Kim likely visited the Kangson enrichment site, although another expert said it was probably another one.

In a post on X, Jeffrey Lewis, a professor of the East Asia Nonproliferation Center at Middlebury Institute for International Studies, compared state media photos of Kim’s visit with the satellite photos of the construction of the Kangson Complex, and determined that the visit was likely to Kangson.

He identified interior wall support columns, exterior office and support areas, and interior enrichment halls identified in satellite photos taken of the construction site of the Kangson Complex in August 2002. 

He said that the same structure was shown in the photo taken of Kim climbing the stairs inside the nuclear facility. 

The double support beam, column supports, and vertical supports shown in the satellite photos taken of the Kangson Complex facility expansion work are the same as those shown in the photos released by North Korean state media.
Jacob Bogle, a private satellite imagery analyst in the United States also believes Kim visited Kangson. 

He told RFA that based on photos released by the North Korean media, the expansion of the Kangson Complex facility is not additional space for more centrifuges, but rather the space required for additional equipment to operate the centrifuges.

Third site?

However, the Stimson Center’s Olli Heinonen, a former deputy director general of the IAEA, pointed out that satellite photos taken of the Kangson Complex expansion work showed partitions being erected to separate spaces, and that such a structure is not suitable for centrifuges.

He said that the space appears to be suitable for offices, warehouses and workspaces.

Heinonen stated that there is a strong possibility that the uranium enrichment facility visited by General Secretary Kim Jong Un in the photo released by North Korean media is not the Kangson Complex.

“You have to be careful when you read the documents of the IAEA,” said Heinonen. “They don't say that is enrichment. They say they think it's enrichment-related.”

Heinonen said the Kangson Complex may not be a uranium enrichment facility but rather a place to manufacture or test centrifuges.

He pointed out that the satellite imagery shows that the Kangson Complex appears to be a two-story or three-story building, and he said that it doesn’t make any sense to have the centrifuge on the first floor and have offices above them.

If an earthquake were to hit the facility, the officers on the higher floors could collapse and destroy the centrifuges below, he said.

Instead, he suggested that Kim may have recently visited a third North Korean uranium enrichment facility, beyond the plants at Kangson and the Yongbyon that may not have been previously known.

“In the second half of the 1990s when they got centrifuges from Pakistan, they installed them to some other location which we don't know,” he said. “It was not in Yongbyon because the IAEA was there all the time. It was not Kangson because Kangson did not exist.”

Bigger threat?

Regardless of which facility Kim toured, the photos of the visit do not reveal anything that changes military threats, according to a report by the Stimson Center’s 38 North project. 

However, it is a “stark reminder of just how menacing the North’s nuclear arsenal is,” the report said, adding that Kim had stressed that ramping up production of nuclear materials was a priority.

“This facility may increase the production of (highly enriched uranium) by around 25 percent, but not exponentially as Kim Jong Un has previously called for,” the report said.

Translated by Claire S. Lee. Edited by Eugene Whong and Malcolm Foster.