Punggye-ri Nuclear Test Site: Work Continues Around South Portal

Recent commercial satellite imagery of North Korea’s Punggye-ri Nuclear Test Sites indicates work to restore Tunnel No. 3 (South Portal) to operational status continues. Two new support buildings have been constructed between April 6 and 14 in the southern support area. A total of four new structures have been added since January, and roof repairs are ongoing at some of the older support buildings, including an old greenhouse, although at a seemingly slower pace than work in the area around the tunnel complex. This investment in support infrastructure suggests long-term plans for site operations, not simply ad hoc actions to support a single test.

The gray-tone spoil pile across the road from the new tunnel entrance continues to expand, albeit gradually and not in the volume expected if new tunneling were ongoing. Southeast of the tunnel entrance, trees have been cleared from a small area, for what purpose is unclear. What appears as black paths near the tunnel entrance may be some kind of water drainage, possibly exiting from the excavated tunnel in combination with recent precipitation. Water drainage from tunneling at Punggye-ri is not an unusual occurrence.

No activity is observed at the North and West Portals or the Command Center.

Figure 1. Activity around the Punggye-ri Nuclear Test Site on April 14, 2022.

Despite wide speculation that North Korea may be preparing to conduct a nuclear test, there have been no obvious signs of preparation activities observed in available imagery, such as increased vehicle activity, especially around the command center area, or arrival of test support equipment and instrumentation.