News reports suggest the possibility of an impending fifth nuclear or mobile ballistic missile test to celebrate the birthday of Kim Jong Un’s grandfather, Kim Il Sung, on April 15. Recent commercial satellite imagery shows little evidence that Pyongyang is planning a nuclear test in the next few days. Nevertheless, that possibility can not be entirely ruled out since the North may be able to conduct a nuclear test on short notice with few indications that it intends to do so.
Imagery from April 9 indicates the presence of a vehicle at the North Portal, the site of the fourth nuclear test in January 2016, as well a few vehicles at the Main Support Area. There is no apparent activity at either the South or West Portals.
Figure 1. Vehicles present at the North Portal on April 9.
The presence of the vehicle at the North Portal indicates continued activity in this area. Since the one discernable tunnel entrance has yet to be sealed—as was the case a few weeks after the 2013 test, to prevent residual radiation leakage—it is possible the entrance may lead to a network of additional tunnels and chambers that can be used for future tests in this area. Moreover, the last three nuclear tests have occurred under Mt. Mantap, as geological surveys indicate that it consists of a particularly desirable form of granite impervious to radioactive gas leakage.
In imagery from April 11, the vehicles are no longer present, the significance is presently unclear.
Figure 2. Vehicles at the North Portal are gone by April 11.
There is no discernible activity at the West Portal. The probable vehicles and crates in front of the northern most building in the Main Support Area, built in 2015 at the same time as the excavation at the West Portal, may be related. Little new spoil has been excavated at the tunnel area. In fact, digging may have stopped in late 2015, which may indicate that the tunnel was completed or work has paused.
Figure 3. No activity at the West Portal.
Figure 4. Some activity at the Main Support Area.