2009 North Korean nuclear test The 2009 North Korean nuclear test was the underground detonation of a nuclear device conducted on Monday , May 25 , 2009 by the Democratic People ' s Republic of Korea . This was its second nuclear test , the first test , a fizzle , having taken place in October 2006 . Following the nuclear test , Pyongyang also conducted several missile tests . A scientific paper later estimated the yield as 2 . 35 kilotons . The test was nearly universally condemned by the international community . Following the test , the United Nations Security Council passed Resolution 1874 condemning the test and tightening sanctions on the country . It is widely believed that the test was conducted as a result of a succession crisis in the country . After Kim Jong - Il suffered a stroke in the summer of 2008 , arrangements were made for his third son , Kim Jong - un , to take power upon his death . It is believed the North Koreans conducted the nuclear test to show that , even in a time of possible weakness , it did not intend to give up its nuclear weapons program . Background . North Korea ( officially the Democratic People ' s Republic of Korea , or DPRK ) had threatened to conduct a second nuclear test in protest after the United Nations Security Council adopted a presidential statement condemning the country after it launched a rocket , which it claimed was carrying the Kwangmyŏngsŏng - 2 satellite , on 5 April 2009 . The launch was condemned by several nations , describing it as an intercontinental ballistic missile test . The test also came after recent messages stating that North Korea had miniaturized nuclear warhead s for medium - range missiles and that the country had been recognized by analysts as a fully fledged nuclear power . In June 2009 , after it was announced that Kim Jong - un was to be the intended successor of North Korean leader Kim Jong - il , U . S . government analysts speculated that the purpose of the nuclear test was to establish North Korea as a nuclear power within Kim Jong - il ' s lifetime . North Korean statements . Without citing a specific time , Pyongyang notified both Washington , D . C . and Beijing of the test about an hour before the actual detonation , which occurred around 10 : 00 Korea Standard Time ( KST ) Monday ; the U . S . State Department promptly contacted the four other six - party talks members . The state - run Korean Central News Agency ( KCNA ) released an announcement claiming , in part , that : This was interpreted as referring to the disputes over the low yield of the 2006 test . Seismic activity . South Korea and Japan reported seismic activity at 09 : 50 KST ( 00 : 50 UTC ) . The United States Geological Survey reported a magnitude 4 . 7 earthquake at a depth of zero and put the center of the tremor about northwest of Kimchaek and northeast of Pyongyang , within a few kilometres of the country ' s 2006 nuclear test site . The Japan Meteorological Agency measured the seismic activity at magnitude 5 . 3 . The Korea Institute of Geoscience & Mineral Resources reported seismic activity in the same area but far stronger than in 2006 . The Russian Defence Ministry confirmed it had detected a nuclear detonation in North Korea and was analysing the data to determine the yield . In China , tremors were felt in the prefecture of Yanbian , which borders North Korea , and forced students in some local schools to be evacuated . The test is believed to have taken place at Mantapsan in the vicinity of P ’ unggyeri ( Korean : ) , which was the site of the nuclear test held in 2006 . Analysis of test . Yield . Analysts have generally agreed that the nuclear test was successful , despite uncertainty of the exact yield . The U . S . intelligence community assessed that North Korea " probably " had conducted a nuclear test with a yield of " a few kilotons . " The Comprehensive Test Ban Treaty Organization Preparatory Commission assessed the yield at only slightly larger than the 2006 test , which was one kiloton . Based on readings from 23 seismic stations , the Preparatory Commission estimated the blast to have a seismic magnitude of 4 . 52 , corresponding to an explosive yield of 2 . 4 kilotons , compared to a seismic magnitude of 4 . 1 , corresponding to a yield of 0 . 8 kilotons , for the 2006 blast . Russia placed the yield of the test significantly higher at 10 to 20 kilotons . This was approximately the yield of the Fat Man and Trinity bombs developed by the United States during World War II . After the 2006 test the Russians estimated a far higher yield of 5 to 10 kilotons when other sources estimated a yield of 0 . 5 to 0 . 9 kilotons . Defense Minister Lee Sang - Hee of South Korea said that more data were needed but that the yield might be between 1 to 20 kilotons . Analyst Martin Kalinowski at the University of Hamburg estimated the yield at being from 3 to 8 kilotons , still a very successful test when compared with the 2006 test . Hans M . Kristensen of the Federation of American Scientists cautioned that " early news media reports about a ' Hiroshima - size ' nuclear explosion seem to be overblown . " The " Bulletin of the Atomic Scientists " asserted that the blast was more powerful than the 2006 test , but put the yield between 2 to 6 kilotons , but likely less than 4 kilotons and far short of a Hiroshima - type device . The group concluded that the bomb failed to detonate correctly , but that still in that case the potential of this weapon should not be dismissed . However , after the subsequent nuclear test in 2013 , the Federal Institute for Geosciences and Natural Resources , a state - run geology research institute in Germany , estimated the yield ranging at minimum of 5 kilotons to the max of 12 kilotons and the 2006 test ranges from minimum of 700 tons to the max of 2 kilotons instead with relevant statistics . Lack of radionuclide confirmation . In June 2009 , the Preparatory Commission for the Comprehensive Nuclear - Test - Ban Treaty Organization ( CTBTO ) announced that no radionuclide s had been detected that could be associated with the 25 May event . At the time of the test , the CTBTO global network included 40 radionuclide sampling stations . In addition , the United States reported that no radionuclides were detected by aircraft over the Sea of Japan ( East Sea of Korea ) , and South Korea also reported that no radionuclides were detected . By contrast , radionuclides were detected in at least two locations after the 2006 event . Lack of detection does not mean that the event was non - nuclear : it is reasonable for a nuclear test with this yield , buried deep enough in the appropriate rock , to not yield remotely detectable radionuclides , but it makes it more difficult to prove whether the test was nuclear . Missile tests . On the same day , North Korea also conducted short - range surface - to - air missile tests . The number of fired missiles was first reported as three , but corrected to two by the South Korean defense ministry on 27 May 2009 . The first missile had a range of . The South Korean news agency Yonhap cited military officials as saying that the launches seemed to be aimed at keeping U . S . and Japanese surveillance planes away from the site . On 26 May 2009 , South Korea ' s Yonhap news agency reported , citing officials , that North Korea fired three more short - range missiles off an east - coast base , one ground - to - ship missile and one surface - to - air missile . The move came as UN diplomats began work on a resolution to punish North Korea for its underground nuclear test . By 27 May 2009 , at least five short range missiles were launched by North Korea . A military spokesman quoted by official media said that North Korea could no longer guarantee the safety of shipping off its west coast , suggesting a missile could also be fired in that direction . Another short - range missile was fired off North Korea ' s east coast on 28 May 2009 . On 29 May 2009 , U . S . officials said that satellite photos revealed vehicle activity at two sites in North Korea suggesting that North Korean military might be preparing to launch a long - range ballistic missile . This was reaffirmed on 1 June 2009 by Defense Secretary Robert M . Gates who said at a news conference with his Philippine counterpart during a brief visit to Manila " We have seen some signs that they may be doing something with another Taepodong - 2 missile , but at this point it ' s not clear what they ' re doing " . Yonhap news agency reported on 2 June 2009 that North Korea was readying as many as three medium - range missiles ( according to some analysts , Rodong missiles ) at a missile base in Anbyon region , Gangwon Province , northeast of the capital of Pyongyang . In addition , a South Korean defence ministry spokesman said that signs that North Korea was preparing to fire an intercontinental ballistic missile ( ICBM ) had been detected . verifying US defense officials ' reports and Defense Secretary Robert M . Gates ' s statement made on 1 June . North Korea apparently has moved the ICBM to a new base in Dongchang - ri along its west coast and a launch could take place in one or two weeks , according to Yonhap . International reaction . The North Korean news agency KCNA confirmed the test as " successful " . The agency also said the test was " aimed at strengthening its self - defense nuclear deterrent in every way " . South Korea ' s Yonhap news agency reported citing KCNA that citizens of Pyongyang held a rally to celebrate the country ' s second successful nuclear test on 26 May . In general the International reactions to the 2009 North Korean nuclear test have been almost uniformly negative . Aftermath . News of the tests immediately affected South Korean markets , sending the main KOSPI share index down 4 % , while the South Korean won dropped by 1 % against the US $ on the day of the nuclear test , 25 May . The yen fell to 95 . 10 per dollar from its level of 94 . 78 on 22 May . On 28 May , North Korea threatened to end the Korean War armistice , stating that " the Korean peninsula will go back to a state of war " , whereupon the joint military command of South Korea and the United States increased its surveillance alert level from WATCHCON 3 to WATCHCON 2 , the second - highest level of surveillance alert . However , the five - stage combat alert level remained at DEFCON 4 , the second - lowest level . Russia undertook security measures in case the war of nerves on the Korean peninsula erupted into a nuclear war . North Korea also threatened on 29 May to attack South Korean and US warships near its coast if its sovereignty were infringed . In Japan a policy debate ensued regarding strengthening its military up to and including the possibility of an independent pre - emptive strike capability and even nuclear armaments , subjects hitherto taboo . On 30 May , the United Kingdom ' s Ministry of Defence confirmed that a VC10 tanker plane , which is used for air - to - air refueling , had been sent to Kadena Air Base in Okinawa , Japan to help support the investigations , led by the U . S . military , to determine the power of the nuclear explosion and the type of material that was used . A Ministry spokesman said : “ Following the recent events in North Korea and to support the international community ’ s efforts during this time of increased political tension , we can confirm that the UK is supporting in the associated verification efforts . ” On the same day , a U . S . F - 22 fighter jet arrived on Kadena Air Base , the first of twelve F - 22 ' s and approximately 280 Langley Air Force Base Airmen from the 94th Fighter Squadron , along with members of the Virginia Air National Guard ' s 192nd Fighter Wing , that are being deployed to Kadena Air Base as part of a theatre security package . U . S . Deputy Secretary of State Jim Steinberg accompanied by Stephen Bosworth , the U . S . special envoy on North Korea , led a U . S . delegation to Asia on 1 June 2009 to consult regional forces on how to respond to North Korea ' s latest nuclear test . The delegation also includes Stuart Levy , the Treasury under - secretary for terrorism and financial intelligence , and Admiral James Winnefeld of the Joint Chiefs of Staff . Japan approved on 2 June 2009 plans for a satellite missile early warning system as part of a new space policy document , a year after Japan dropped a decades - old ban on military use of space with some ruling party lawmakers suggesting Japan should inspect North Korean ships , in the wake of reports that N . Korea was preparing to fire more mid - range missiles . On the same day , as a response to the increased activity of the N . Korean military and after reports that North Koreans have stepped up naval drills near the western sea border , the site of deadly skirmishes between the two Koreas in 1999 and 2002 , South Korea deployed a high - speed naval vessel , the Yoon Youngha guided missile patrol boat , to the area and vowed to " punish " any attacking forces . After the North Korean nuclear test the U . S . has approved the sale of a number of weapon systems to South Korea , including GBU - 28 " bunker buster " bombs , SM - 2 Standard surface - to - air Missiles and F - 16 Block 32 Aircraft Upgrades improving the aircraft and increasing the South Korean military ' s operational abilities . The South Korean military has prepared plans for a counter - attack in the event of a first strike by North Korea . UNSC Resolution 1874 . The United Nations Security Council unanimously adopted resolution 1874 in response to the test , imposing further economic sanctions on the country and authorising UN member states to inspect North Korean cargo and destroy any that may be involved in the nuclear weapons program . In response to the sanctions , an unidentified spokesman for the North Korean Foreign Ministry released a statement through the official Korean Central News Agency saying that the country would begin to " weaponize " its plutonium stockpiles . The spokesman also said the country " will start uranium enrichment " and would view any US - led attempts to " blockade " it as an " act of war " . The statement was said to have lacked the usual bitterness of most North Korean statements .