The Defense Intelligence Agency (DIA) of the United States has noted that excavation activities are currently underway at an underground facility in Hichun, North Hamgyong Province, initially flagged in 1998 as a potential site for nuclear-related facilities.
Recent developments reported by Radio Free Asia (RFA) from satellite imagery provided by Planet Labs indicate significant changes at the site. Between late February and early March, a new entrance appeared on the hillside, accompanied by an accumulating debris pile, which was not visible in satellite images from February 16 but confirmed in images by March 23. Further satellite images taken in June, August, and September showed that the debris pile area had grown, suggesting ongoing excavation work.
Civilian satellite expert Jacob Bogle explained that as of September this year, the debris pile covers an area of about 17,000 square meters. He noted that while it’s difficult to determine the exact height from the photos if the pile is around 5 meters high, it would suggest approximately 252,650 tons of granite have been removed.
Jacob Bogle, a civilian satellite expert, estimated that as of September, the debris-covered approximately 17,000 square meters. If the pile reaches a height of 5 meters, it would contain about 229,500 tons of granite. Bogle remarked that the volume of debris indicates that the internal space of the Hichun facility might surpass that of North Korea’s major nuclear sites like Yongbyon or Gangseon.
Construction at the Haegap underground facility was also identified in 2017 and 2019. In 2017, a massive pile of debris accumulated around the main entrance, and in 2019, a new entrance was created through tunnel construction, allowing vehicle access.
Jung Sung Hak, a member of the Korea Institute for Security Strategy, observed that activities releasing warm wastewater from the Haegap facility were visible between 2007 and 2021. He suspected that nuclear-related facilities might be underground, suggesting that Hichun could be a likely candidate for a third nuclear facility site.
Olli Heinonen, a former Deputy Director-General of the International Atomic Energy Agency (IAEA) and now a distinguished fellow at the Stimson Center, also told RFA that the uranium enrichment facility Kim Jong Un recently visited could be a third site, neither Yongbyon nor Kangson.
North Korean media reported on September 13 that Kim had visited a uranium enrichment facility but did not specify the location.
In response to reports that Kim visited the nuclear facility in Kangson rather than Yongbyon, the South Korean military stated, “U.S. and South Korean intelligence authorities are continuously tracking and monitoring North Korea’s nuclear weapons development trends,” adding, “We have nothing to disclose regarding the facility.”