A 38 North exclusive with analysis by Joseph S. Bermudez Jr. and Jack Liu

Commercial satellite imagery of the Punggye-ri nuclear test site indicates the presence of possibly four or five vehicles or trailers at the entrance to the North Portal, the site of North Korea’s past four nuclear tests.

If these vehicles are related to test preparations, they could be involved in the installation of instrumentation or even a nuclear device. However, the evidence is not definitive, therefore they may be there for other purposes as well.

Imagery also indicates that a pile of construction material, probably sand and aggregate, located in the nearby storage lot, appears undisturbed compared to previous images. That material, if it is sand and aggregate, when mixed with concrete, may be intended to “stem,” that is to plug segments of the tunnel to prevent a nuclear explosion from escaping into the atmosphere. While this conclusion is not definitive, there is evidence of some recent dumping of material on top of the tailings pile, indicative of either clearing away rubble or waste from stemming.

Figure 1. Probable equipment or trailers seen near entrance to North Portal.

Figure 2. Recent dumping activity seen at the North Portal’s spoil pile.

Apart from two trucks and several mining carts at the West Portal, there is little apparent activity elsewhere at the Punggye-ri nuclear test site. Once again, the lack of activity may mean either that Pyongyang is in the final stages of test preparation or that the site is in a standard operating mode.

Figure 3. Two small trucks seen near entrance to West Portal.