|Fig. 1: North Korea will shut down its main nuclear test site in Punggye-ri. (Source: Wikimedia Commons)|
North Korean leader Kim Jong Un has said that North Korea plans to shut down its main nuclear test site in May of 2018.  Kim made comments about shutting down the Punggye-ri nuclear test site at a summit with South Korean President Moon Jae-in located demilitarized zone between the two countries. [1,2] This summit was the first face- to-face discussion between North and South Korean leaders since 2007, and it called for the end of the Korean war, a new era of peace, and committing to the complete denuclearization of the peninsula.  The Punggye-ri nuclear test site is located in north-eastern North Korea, as seen in Fig. 1.
South Koreas presidential office provided details of a meeting between Kim and Moon Friday, April 27th in which Kim Jong Un reaffirmed his willingness to give up nuclear weapons in exchange for a security guarantee from the United States. 
Kim was quoted, The United States, though inherently hostile to North Korea, will get to know once our talk begins that I am not the kind of person who will use nuclear weapons against the South or the United States across the Pacific. 
Newly affirmed secretary of State Mike Pompeo said in an interview broadcast April 29th that the trump administration was going into negations with North Korea with eyes wide open and emphasized irreversible denuclearization as a main target of upcoming talks. Although the meetings between North Korean and United States leadership are yet to be given an actual date. 
Kim went on to say, Why would we need to live under such difficult conditions with nuclear weapons if were able to build trust with the U.S. at future meetings, and the U.S. promises nonaggression and an end to the Korean War? - from Yoon Youngchan, a spokesman for South Koreas presidential office. 
It is unclear whether this was strictly a political move in preparation for talks with the United States, or whether North Korea was forced to halt testing.  In a recent study, a group of geologists discovered that the mountain used by North Korea for its testing site has collapsed as a result of the explosions.  Scientists from the University of Science and Technology of China believe this could be the true reason that Kim Jong-un announced the closing of the Punggye-ri site and the halting of their nuclear testing program. [2,4]
The collapse of Mount Mantap was the result of five recent nuclear bomb explosions at the Punggye-ri test site in northwest North Korea. [2,5] The blasts tore open a hole in the mountain, causing it to collapse and creating a pathway for radioactivity to escape from the mountain. [2,5] There are raising concerns that radioactive fallout could make its way into China.  It is believed that the collapse was the result of the detonation of North Koreas most powerful bomb, a 100-kilotonne nuclear bomb. [2,5]
However, Kim maintained in comments at the summit that the Punggye-ri site is in fine condition, and that the nuclear explosions have not damaged the testing site. [1,3] He is adamant that the shut down is not happening because the site is unusable. Kim said that he would discuss with South Korea the possibility of inviting experts and journalists from the United States and South Korea to demonstrate the closure of the site. Some claim we are closing down an unusable test site, but if they come and see, they will understand that there are two bigger tunnels than the existing test facilities and that they are in a very good condition," Kim said, according to Yoon. 
© Drew Holland. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 B. Wescott, Y. Seo, and S. Jeong, "North Korea will close nuclear test site in May, South says," CNN, 29 Apr 18.
 T. Nace, "This Could Be The Real Reason Why North Korea Stopped Its Nuclear Missile Tests," Forbes, 26 Apr 18.
 J. Cheng and A. Jeong, "North Korea Vows to Shut Down Nuclear Test Site, Seoul Says," Wall Street Journal, 29 Apr 18.
 M. W. Bishop, "North Korea's Vow to Shut Punggye-ri Nuclear Site Appears Mostly Symbolic," NBC News, 30 Apr 18.
 L. Zhang et al., "Impact of North Korean Nuclear Weapons Test on 3 September, 2017 on Inland China Traced by C-14 and I-129," J. Radioanal. Nucl. Chem. 316, 383 (2018).