On April 20, North Korea made the dramatic announcement[1] of several decisions that included suspending further nuclear and missile tests and that its “nuclear test center would be discarded in order to ensure the transparency of the suspension of the nuclear test.”[2] A number of analysts, including a Washington Post column by Max Boot on Saturday, mistakenly dismiss the offer by claiming that the test site is probably unusable anyway.

North Korea’s Punggye-ri Nuclear Test Site, where North Korea has conducted six acknowledged underground detonations is still, as far as we can tell, fully operational. Following Pyongyang’s sixth nuclear test in September 2017, one area at the site—the North Portal, located at Mount Mantap where the last five underground nuclear tests had been conducted—was apparently abandoned. However, significant new tunneling was noted at the West Portal, another area of the site, up through early March 2018. That renewed tunneling was curtailed by mid-March, but not entirely stopped through early April, suggesting that either the tunnel was complete and ready for future renewed testing or that the slowdown simply mirrored the ongoing political changes underway.

Another potential test tunnel, accessible via the South Portal, includes a primary and secondary entrance. Complete for several years now, that area also remains suitable for future underground nuclear tests. In general, there have been fewer personnel and vehicular movements there than observed near the other portals, but nonetheless is still an alternative for additional testing in the future.

In short, there is no basis to conclude that the Punggye-ri nuclear test site is no longer viable for future nuclear testing. There remain two portal areas located in more pristine competent rock that can be used for future tests if Pyongyang were to give the order. Whether that will stay an option will depend on reaching verifiable agreements that build on Pyongyang’s pledge to shut down the facility.