North Korea builds new Yongbyon enrichment facility

A new uranium-enrichment facility at North Korea’s Yongbyon nuclear complex can accommodate up to 28 cascades of centrifuges, according to an International Atomic Energy Agency report dated 28 August. The assessment is based on satellite imagery and open-source material, after Pyongyang expelled IAEA inspectors in 2009 and has kept them out since.

According to Infobae’s summary of the IAEA findings, the agency identified a new two-storey building at Yongbyon by matching satellite images taken during construction with photographs released by North Korean state media during Kim Jong-un’s visit in early June. The IAEA also reported that an expanded enrichment plant at Kangson near Pyongyang has started operating, with operations said to have begun earlier this year. Both developments violate UN Security Council resolutions prohibiting North Korea from uranium-enrichment activity, but the enforcement mechanism has largely been reduced to statements and sanctions lists.

The Yongbyon complex has long been the most legible symbol of North Korea’s nuclear program: a site that can be watched from orbit even when it cannot be visited on the ground. That asymmetry shapes the diplomacy. When verification depends on imagery and inference, each new building becomes a political fact before it becomes an inspected one, and outside powers are left arguing over floor plans rather than negotiating over monitored production.

The IAEA’s director general, Rafael Grossi, said the continued operation and expansion of enrichment facilities was a matter of “serious concern,” according to the report. North Korea withdrew from the Nuclear Non-Proliferation Treaty in 2003 after an earlier agreement with Washington collapsed, and bilateral talks have remained stalled since the last burst of summit diplomacy ended in 2019. In June, Kim said North Korea’s capacity to produce weapons-grade nuclear material had more than doubled in the past five years, a claim the IAEA cannot independently verify without inspectors.

Outside estimates fill the gap. Infobae cites a 2025 analysis by the James Martin Center for Nonproliferation Studies suggesting that a 28-cascade configuration—amounting to thousands of centrifuges—could produce enough highly enriched uranium annually for several additional warheads. Even if the exact output is unknowable from satellite images alone, the direction of travel is not: more buildings, more cascades, more redundancy.

For sanctions policy, the problem is less whether a new facility is “confirmed” than what happens when the cost of adding capacity is borne domestically while the cost of responding—missile defence, intelligence collection, extended deterrence—is spread across neighbours and allies. The IAEA can document construction and issue warnings; it cannot compel access.

The report’s most concrete detail is also the most telling: after more than 15 years without inspectors, the world is still counting North Korea’s centrifuges by looking at rooftops.