2017 North Korean nuclear test

2017 North Korean nuclear test
M 6.3 Explosion - 22km ENE of Sungjibaegam, North Korea.jpg
Graphic from the United States Geological Survey showing the location of seismic activity at the time of the test
CountryNorth Korea
Test site41°20′35″N 129°02′10″E / 41°20′35″N 129°02′10″E / 41.343; 129.036[1]
Punggye-ri Nuclear Test Site, Kilju County
Period12:00:01, 3 September 2017 (2017-09-03T12:00:01) UTC+08:30 (03:30:01 UTC)[1]
Number of tests1
Max. yield
Test chronology
Location of North Korea's Nuclear tests[4][5]
12006; 22009; 32013; 42016/1; 52017;

North Korea conducted its sixth nuclear test on 3 September 2017, stating it had tested a thermonuclear weapon (hydrogen bomb).[6]

The United States Geological Survey reported an earthquake of 6.3-magnitude not far from North Korea's Punggye-ri nuclear test site.[7] South Korean authorities said the earthquake seemed to be artificial, consistent with a nuclear test.[8] The USGS, as well as China Earthquake Networks Center, reported that the initial event was followed by a second, smaller, earthquake at the site, several minutes later, which was characterized as a collapse of the cavity.[9][10]

Nuclear device

Order to conduct the test, signed by Kim Jong-un on 3 September 2017

The North Korean government announced that it had detonated a hydrogen (thermonuclear) bomb that could be loaded onto an intercontinental ballistic missile (ICBM).[11] The announcement stated the warhead had a variable yield "the explosive power of which is adjustable from tens kiloton to hundreds kiloton ... which can be detonated even at high altitudes for super-powerful EMP attack".[12] A later technical announcement called the device a "two-stage thermo-nuclear weapon" and stated experimental measurements were fully compatible with the design specification, and there had been no leakage of radioactive materials from the underground nuclear test.[13][6]

Photographs of North Korean leader Kim Jong-un inspecting a device resembling a thermonuclear weapon warhead were released a few hours before the test.[14]

Analysts have tended to give credence to North Korea's claim that it was a hydrogen bomb.[15][16] 38 North made a revised estimate for the test yield at 250 kT, making it near the maximum-containable yield for the Punggye-ri test site.[17] Tom Plant, director of proliferation and nuclear policy at the Royal United Services Institute said, "The North Koreans do bluff sometimes, but when they make a concrete claim about their nuclear programme, more often than not it turns out to be true. ... I think the balance is in favour of it being a thermonuclear bomb rather than a conventional atom bomb."[18]

Others have been skeptical that it was a completely successful test of a true hydrogen bomb as North Korea claimed. Determining whether it is a two-stage thermonuclear bomb or a fusion-boosted fission weapon may not be possible without radionucleide emission data.[19][16] The yield estimates of less than 300 kT would be lower than any other nation's first test of a fusion-primary thermonuclear device, which would typically be in the 1000 kT range, while boosted fission weapons and variable-yield nuclear devices can be as low as hundreds of tons, but are not considered true hydrogen bombs; meanwhile the largest pure-fission bomb tested was Ivy King at 500 kT.[20][better source needed] An October 2 Scientific American article said the test was "estimated to have been a 160-kiloton detonation — far below an H-bomb's capabilities."[21] Martin Navias of the Centre for Defence Studies at King's College London noted that the breakthroughs needed to get from a fission to a fusion device would have to be done by the North Koreans on their own – China, Russia, Pakistan, and Iran would not or could not help.[18]

Jane's Information Group estimates a North Korean thermonuclear Teller-Ulam type bomb would weigh between 250 and 360 kilograms (~550 - 790 lbs.).[22]

As of January 2018 there have been no official announcements from the United States confirming or contraindicating the detonation of a hydrogen bomb. However, on 15 September 2017 John E. Hyten, head of U.S. Strategic Command, said, "When I look at a thing this size, I as a military officer assume that it's a hydrogen bomb."[23]

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