Jeffrey LewisChanges at Punggye-ri

Jeffrey Lewis and Dave Schmerler

Construction is occurring at North Korea’s nuclear test site for the first time since North Korea announced the closure and dismantlement of the site in spring 2018.

In April 2018, Kim Jong Un announced an end to nuclear explosive testing and tests of intermediate- and intercontinental-range ballistic missiles. In May, North Korea invited a small number of journalists to witness the dismantling of the test site.  The journalists viewed a series of explosions that sealed the tunnel entrances and destroyed some buildings.

With the collapse of negotiations, North Korea has made clear the 2018 moratoria are no longer operative. In December 2019, Kim Jong Un said North Korea was no longer bound by the moratoria.

More recently, in January 2022, North Korea announced that it would “make an overall reconsideration of the confidence-building measures that we have taken on our own initiative and on a prior basis and to promptly examine the issue of restarting all temporarily-suspended activities.”

We have been monitoring the Punggye-ri nuclear test site closely for signs that North Korea was beginning to repair the site since the January 2022 announcement. South Korean officials in recent days have also indicated they would “even more closely” monitor the site.

On March 4, Maxar imaged the nuclear test site at Punggye-ri.  In the image, we see very early signs of activity at the new site, including construction of a new building, repair of another building, and what is possibly some lumber and sawdust.  North Korea uses a substantial amount of wood at the site both for buildings and shoring up tunnels.  These changes have occurred only in the past few days.

These activities are very preliminary. One aspect of having so many commercial satellites in orbit is that we often catch construction activities in their very early stages, when it is difficult to conclude what precisely is being built or why.  However, this is the first activity we have seen at the site since North Korea dismantled it in May 2018. 

The construction and repair work indicate that North Korea has made some decision about the status of the test site.  One possibility is that North Korea plans to bring the test site back to a state of readiness to resume nuclear explosive testing, consistent with the statement North Korea issued in January to “examine the issue of restarting all temporarily-suspended activities.”  

The test site is many months, if not years, from being ready for North Korea to conduct nuclear explosions there.  How long it would take North Korea to resume explosive testing at the site depends on the extent of the damage to the tunnels themselves, something we do not know with confidence. It is also possible that North Korea will resume nuclear testing at another location. 

If North Korea were to resume nuclear testing it could further improve its confidence in its large thermonuclear weapon with a yield greater than 100 kilotons or it could validate new tactical nuclear weapons for its stockpile of shorter-range ballistic and cruise missiles.