"I greatly appreciate your very swift response, and your organization's work in general. It's a terrific source of authoritative information."

– Lisa Beyer
Bloomberg News
August 27, 2018
Defying Global Taboo, North Korea Conducts 3rd Nuclear Blast

Arms Control NOW

By Daryl G. Kimball and Greg Thielmann

The DPRK's Punggye-ri nuclear test site April 18, 2012 The DPRK's Punggye-ri nuclear test site April 18, 2012.

The government of the Democratic People's Republic of Korea (DPRK) has apparently conducted its third nuclear test explosion, defying the explicit demands of the UN Security Council and the international community that it "abandon all nuclear weapons and existing nuclear programmes in a complete, verifiable and irreversible manner."

The Executive Secretary of the Comprehensive Test Ban Treaty Organization (CTBTO), Tibor Toth, issued the following statement on Feb. 12 at 04:19:17 CST:

"Today our monitoring stations picked up evidence of an unusual seismic event in the Democratic People's Republic of Korea (DPRK). The event shows clear explosion-like characteristics and its location is roughly congruent with the 2006 and 2009 DPRK nuclear tests. For now, further data and analysis are necessary to establish what kind of event this is. If confirmed as a nuclear test, this act would constitute a clear threat to international peace and security, and challenges efforts made to strengthen global nuclear disarmament and non-proliferation, in particular by ending nuclear testing."

Nuclear test explosions produce seismic signatures that are distinct from earthquakes and chemical high explosions. Underground nuclear test explosions also emit small quantities of certain types of radioactive gases that can be detected by mobile air monitoring equipment deployed by the U.S. Air Force, and, depending on weather patterns, by certain ground stations controlled by Russia, Japan, and South Korea, as well as the international radionuclide monitoring stations that are part of the CTBTO's International Monitoring System.

The CTBTO reports that their first and preliminary automatic detections were made by up to 25 seismic stations around the world. The first data were made available to CTBTO Member States in little more than one hour.

According to the CTBTO, the event measured 5.0 in magnitude, which is around twice as large as the DPRK's nuclear test in 2009 (4.52) and much larger than the one in 2006 (4.1).

In October 2006, the International Monitoring System easily detected Pyongyang's relatively low-yield (0.6 kiloton) nuclear explosion at 22 seismic stations. Expert analysis of the data suggested the test was not entirely successful. Telltale radioactive gases from the 2006 test were also detected by South Korea and the United States, as well as one of the international monitoring network's radionuclide monitoring stations 4,600 miles away in Canada. North Korea's second test in May 2009 was detected by 61 seismic stations operated by the CTBTO as a nuclear detonation. The 2009 test is estimated to have produced a yield of 2-6 kilotons. The South Korean defense ministry has provided a preliminary yield estimate of 6-7 kilotons for the latest test.

North Korea announced today that it had conducted a third nuclear test of "a miniaturized and lighter device with greater explosive force" than previous tests, according the official KCNA news agency.

The characteristics of the nuclear explosion and the fuel used for the bomb are not apparent at this time. A more detailed analysis of data collected on the test explosion will follow in the coming days.

North Korea is believed to have sufficient plutonium for four to eight nuclear bombs and may also have highly enriched uranium (HEU) for additional weapons--precisely how much HEU they may have is not clear.

As part of the six-party denuclearization process, North Korea shut down its plutonium-production facility at Yongbyon in July 2007, but it has built uranium centrifuge arrays that could be improved and expanded to enable it to generate enough highly enriched uranium for one to two bombs per year.

This latest test and any further nuclear testing could provide North Korean scientists with additional information for nuclear warhead designs small enough to fit on top of its ballistic missiles. However, it is likely that additional testing would be needed for North Korea to field either a plutonium or enriched uranium weapon.

According to Frank Pabian and Siegfried Hecker, writing in the August 6, 2012 edition of The Bulletin of Atomic Scientists, "an additional nuclear test or two would greatly increase the likelihood that Pyongyang could fashion warheads to fit at least some of its missiles..."

What Now?

North Korea's latest nuclear test is not just a rebuke of the international community's call for nuclear restraint, but an embarrassment for China's leaders. Consequently, Pyongyang may have jeopardized the aid and diplomatic support it receives from China, its only significant ally.

China has reacted negatively to both of the previous tests, issuing unusual public criticism after the second. However, it did not significantly curtail aid and assistance following the first two tests. This time, Beijing signaled through its state-controlled media prior to the test that if North Korea engaged in further nuclear tests, China "will not hesitate to reduce its assistance..."

Although some experts believe Chinese influence on Pyongyang is overestimated, others like former U.S. envoy on the DPRK nuclear issue, Christopher Hill, argue that Beijing could do much more to apply pressure. Past Chinese diplomatic and economic support has allowed North Korea to ignore world opinion, in spite of the desperate state of its economy and hunger-ravaged population. It is important that Beijing now demonstrate its last warning was sincere and that the unanimous resolutions of the UN Security Council demand respect.

North Korea does not deny its interest in nuclear weapons. Its thin pretense of interest in the peaceful use of space in connection with its satellite launch attempts, was stripped away by Pyongyang's recent rhetorical riffs, including its January 23 statement "to bolster its military capabilities for self defense, including...nuclear deterrence."

Nonetheless, North Korea has a long way to go before it can credibly threaten the United States with nuclear weapons. It is likely to be years away from fielding an ICBM, which could deliver a nuclear warhead to the U.S. mainland. There is still time to halt and reverse current trends before North Korea's nuclear capabilities become more substantial.

The seriousness of this issue demands a full court press by the international community. The United States needs to work more closely than ever to coordinate policy with other stakeholders in the region. While it is important not to reward irresponsible behavior, it is also irresponsible to retreat under the rubric of "strategic patience" or other forms of benign neglect. Naming and shaming and further sanctions on the DPRK are certainly justified in the wake of the latest nuclear test, but by themselves, such responses have not produced adequate results.

As difficult as Pyongyang's leaders are, opportunities must be sought and seized to resume talks designed to curtail North Korea's nuclear and missile capabilities, and Beijing's leaders must be willing to pull back their economic assistance to the Pyongyang regime and fully enforce the international sanctions already on the books.

The latest DPRK nuclear test explosion--the world's 2,053rd and only the third test since 1998--also makes it all the more important that the major nuclear-armed states, specifically the U.S. and China, reinforce the global taboo against testing by taking concrete action to bring the CTBT into force, which will help us better detect and deter nuclear testing by any state in the future.

As President Barack Obama said in 2009, "After more than five decades of talks, it is time for the testing of nuclear weapons to finally be banned." Indeed.

As Siegfried Hecker, former director of the Los Alamos National Laboratory wrote in September 2012: "The testing moratorium by the major nuclear countries did not stop Pyongyang from testing and it may not be a decisive factor in Tehran's decision as to whether it may test in the future. However, the increased international pressure of a ratified CTBT may increase the effectiveness of international constraints and possibly affect their decision."