North Korea Expands Uranium Enrichment Capacity at Yongbyon and Kangson

The International Atomic Energy Agency (IAEA) reported that a newly constructed two-storey building at the Yongbyon nuclear complex can accommodate up to 28 centrifuge cascades. Satellite imagery and photographs released by North Korean state media after Kim Jong un’s June 3, 2026 visit show centrifuge assemblies on both floors. In the same assessment, the IAEA identified an expanded annex at the Kangson enrichment site near Pyongyang that has shown operational signs since January 2026. Together, these observations indicate a continued increase in the Democratic People’s Republic of Korea’s (DPRK) uranium enrichment capacity.

The Straits TimesNorth Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon North Korea Expands Uranium Enrichment at Yongbyon and Kangson, IAEA Says IAEA: NK's Yongbyon facility can hold up to 28 centrifuge cascades

The IAEA has not deployed inspectors inside North Korea since 2009, relying on open-source material and commercial satellite data to monitor the program. Earlier reports documented a single enrichment facility at Yongbyon and a smaller plant at Kangson. The agency’s September 9, 2026 report, submitted to its Board of Governors and the 70th General Conference on August 28, expands the known footprint of the DPRK’s enrichment infrastructure.

North Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon The Straits TimesNorth Korea Expands Uranium Enrichment at Yongbyon and Kangson, IAEA Says IAEA: NK's Yongbyon facility can hold up to 28 centrifuge cascades

• Yongbyon UEF-2: Designed for up to 28 centrifuge cascades; construction began in December 2024, the exterior was completed in May 2025, and power-supply equipment was installed between June and October 2025.

North Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon

• Kangson Annex: Built alongside the existing building in 2024; operational indicators have been observed since January 2026.

North Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon

• Photographic Evidence: Images released on June 3, 2026 display cascades on both levels of the Yongbyon structure.

North Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon

The IAEA cautioned that it cannot verify the exact number of centrifuges per cascade, their performance, or the current operating rate, and therefore did not estimate the quantity of highly enriched uranium that could be produced.

IAEA: NK's Yongbyon facility can hold up to 28 centrifuge cascades

The North Korean government’s dismissal of the IAEA’s findings constitutes formal opposition to the agency’s assessment and to the broader non-proliferation framework.

North Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon

The IAEA’s analysis acknowledges significant uncertainties: it cannot confirm the precise configuration of centrifuge cascades, their operational efficiency, or the amount of weapons-grade material being produced. No independent on-site verification is possible, leaving a gap in quantitative understanding of the DPRK’s enrichment output.

IAEA: NK's Yongbyon facility can hold up to 28 centrifuge cascades

An expanded uranium enrichment capability enhances the DPRK’s ability to produce weapons-grade material, raising regional security concerns and potentially prompting additional United Nations sanctions. The development also underscores the limitations of the IAEA’s monitoring tools when access to a state is denied.

IAEA: NK's Yongbyon facility can hold up to 28 centrifuge cascades

The IAEA’s findings are slated for discussion at its 70th General Conference, scheduled for mid-September 2026 in Vienna. The agency’s Board of Governors will consider the report alongside ongoing diplomatic efforts aimed at curbing the DPRK’s nuclear program.

North Korea: IAEA Identifies Second Uranium Enrichment Facility at Yongbyon