North Korea builds second uranium enrichment facility at Yongbyon, IAEA warns

North Korea has constructed a second uranium enrichment facility at its Yongbyon nuclear complex, the International Atomic Energy Agency confirmed in a report released September 9, 2026. The building is two storeys tall, mirrors the design of an existing enrichment plant, and could accommodate up to 28 gas centrifuge cascades. To put that in context: centrifuge cascades are the spinning machines that concentrate uranium into weapons-grade material. More cascades means more fissile material, faster. Twenty-eight of them in a single building is not a small footnote. What the IAEA found, and how it found it The agency’s conclusions rest primarily on satellite imagery, state media photographs, and open-source analysis, because IAEA inspectors have been barred from North Korean soil since 2009. State media images from Kim Jong Un’s visit to the site in June 2026 provided an inadvertent look inside. Independent groups including VERTIC and CSIS Beyond Parallel reviewed the same imagery and reached consistent conclusions about the facility’s scale and purpose. According to the IAEA’s timeline, construction at the new Yongbyon plant began in mid-to-late 2024. The exterior was complete by mi...