List of nuclear weapons tests
Nuclear weapons testing is the act of experimentally and deliberately firing one or more nuclear devices in a controlled manner pursuant to a military, scientific or technological goal. This has been done on test sites on land or waters owned, controlled or leased from the owners by one of the eight nuclear nations: the United States, the Soviet Union, the United Kingdom, France, China, India, Pakistan and North Korea, or has been done on or over ocean sites far from territorial waters. There have been 2,121 tests done since the first in July 1945, involving  2,476 nuclear devices. As of 1993, worldwide, 520 atmospheric nuclear explosions (including 8 underwater) have been conducted with a total yield of 545 megaton (Mt): 217 Mt from pure fission and 328 Mt from bombs using fusion, while the estimated number of underground nuclear tests conducted in the period from 1957 to 1992 is 1,352 explosions with a total yield of 90 Mt. Very few unknown tests are suspected at this time, the Vela Incident being the most prominent. Israel is the only country suspected of having nuclear weapons but not known to have ever tested any. The following are  considered nuclear tests: Not included as nuclear tests: Tests by country. The table in this section summarizes all worldwide nuclear testing (including the two bombs dropped in combat which were not tests). The country names are links to summary articles for each country, which may in turn be used to drill down to test series articles which contain details on every known nuclear explosion and test. The notes attached to various table cells detail how the numbers therein are arrived at. Known tests. In the following subsections, a selection of significant tests (by no means exhaustive) is listed, representative of  the testing effort in each nuclear country. United States. The standard "official" list of tests for American devices is arguably the United States Department of Energy DoE-209 document. The United States conducted around 1,054 nuclear tests (by official count) between 1945 and 1992, including 216 atmospheric, underwater, and space tests. Some significant tests conducted by the United States include: Soviet Union. After the fall of the USSR, the American government (as a member of the International Consortium "International Science and Technology Center") hired a number of top scientists in Sarov (aka Arzamas-16, the Soviet equivalent of Los Alamos and thus  sometimes called "Los Arzamas") to draft a number of documents about the history of the Soviet atomic program. One of the documents was the definitive list of Soviet nuclear tests. Most of the tests have no code names, unlike the American tests, so they are known by their test numbers from this document. Some list compilers have detected discrepancies in that list; one device was abandoned in its cove in a tunnel in Semipalatinsk when the Soviets abandoned Kazakhstan, and one list lists 13 other tests which apparently failed to provide any yield. The source for that was the well  respected "Russian Strategic Nuclear Forces" which confirms 11 of the 13; those 11 are in the Wikipedia lists. The Soviet Union conducted 715 nuclear tests (by the official count) between 1949 and 1990, including 219 atmospheric, underwater, and space tests. Most of them took place at the Semipalatinsk Test Site in Kazakhstan and the Northern Test Site at Novaya Zemlya. Additional industrial tests were conducted at various locations in Russia and Kazakhstan, while a small number of tests were conducted in Ukraine, Uzbekistan, and Turkmenistan. In addition, the large-scale military exercise was conducted by Soviet army to explore the  possibility of defensive and offensive warfare operations on the nuclear battlefield. The exercise, under code name of "Snezhok" (Snowball), involved detonation of a nuclear bomb twice as powerful as the one used in Nagasaki and approximately 45,000 soldiers coming through the epicenter immediately after the blast The exercise was conducted on September 14, 1954, under command of Marshal Georgy Zhukov to the north of Totskoye village in Orenburg Oblast, Russia. Some significant Soviet tests include: The last Soviet test took place on October 24, 1990. After the dissolution of the USSR in 1992, Russia inherited the USSR's nuclear stockpile , while Kazakhstan inherited the Semipalatinsk nuclear test area, as well as the Baikonur Cosmodrome, the Sary Shagan missile/radar test area and three ballistic missile fields. Semipalatinsk included at least the one unexploded device, later blown up with conventional explosives by a combined USA/Kazakh team. No testing has occurred in the former territory of the USSR since its dissolution. United Kingdom. The United Kingdom has conducted 45 tests (12 in Australian territory, including 3 in the Montebello Islands of Western Australia and 9 in mainland South Australia (7 at Maralinga and 2 at Emu Field); 9 in the Line  Islands of the central Pacific (3 at Malden Island and 6 at Kiritimati/Christmas Island); and 24 in the U.S. as part of joint test series). Often excluded from British totals are the 31 safety tests of Operation Vixen in Maralinga. British test series include: Last test: Julin Bristol, November 26, 1991, vertical shaft. Atmospheric tests involving nuclear material but conventional explosions: France. France conducted 210 nuclear tests between February 13, 1960 and January 27, 1996. Four were tested at Reggane, French Algeria, 13 at In Ekker, Algeria and the rest at Moruroa and Fangataufa Atolls in French Polynesia. Often  skipped in lists are the 5 safety tests at Adrar Tikertine in Algeria. China. The foremost list of Chinese tests compiled by the Federation of American Scientists skips over two Chinese tests listed by others. The People's Republic of China conducted 45 tests (23 atmospheric and 22 underground, all conducted at Lop Nur Nuclear Weapons Test Base, in Malan, Xinjiang) India. India announced it had conducted a test of a single device in 1974 near Pakistan's eastern border under the codename "Operation Smiling Buddha". After 24 years, India publicly announced five further nuclear tests on May 11 and  May 13, 1998. The official number of Indian nuclear tests is six, conducted under two different code-names and at different times. Pakistan. Pakistan conducted 6 official tests, under 2 different code names, in the final week of May 1998. From 1983 to 1994, around 24 nuclear cold tests were carried out by Pakistan; these remained unannounced and classified until 2000. In May 1998, Pakistan responded publicly by testing 6 nuclear devices. North Korea. On October 9, 2006, North Korea announced they had conducted a nuclear test in North Hamgyong Province on the northeast coast at 10:36 AM (11:30 AEST ). There was a 3.58 magnitude earthquake reported in South Korea, and a 4.2 magnitude tremor was detected 240 miles north of P'yongyang. The low estimates on the yield of the test—potentially less than a kiloton in strength—have led to speculation as to whether it was a fizzle (unsuccessful test), or not a genuine "nuclear" test at all. On May 25, 2009, North Korea announced having conducted a second nuclear test. A tremor, with magnitude reports ranging from 4.7 to 5.3, was detected at Mantapsan, 233 miles northeast of P'yongyang and within a few kilometers of the 2006 test  location. While estimates, as to yield, are still uncertain, with reports ranging from 3 to 20 kilotons, the stronger tremor indicates a significantly larger yield than the 2006 test. On 12 February 2013, North Korean state media announced it had conducted an underground nuclear test, its third in seven years. A tremor that exhibited a nuclear bomb signature with an initial magnitude 4.9 (later revised to 5.1) was detected by both Comprehensive Nuclear-Test-Ban Treaty Organization Preparatory Commission (CTBTO) and the United States Geological Survey (USGS). The tremor occurred at 11:57 local time (02:57 UTC) and the USGS said  the hypocenter of the event was only one kilometer deep. South Korea's defense ministry said the event reading indicated a blast of six to seven kilotons. However, there are some experts who estimate the yield to be up to 15 kt, since the test site's geology is not well understood. In comparison, the atomic (fission) bombs dropped by the "Enola Gay" on Hiroshima (Little Boy, a "gun-type" atomic bomb) and on Nagasaki by "Bockscar" (Fat Man, an "implosion-type" atomic bomb) had blast yields of the equivalents of 15 and 21 kilotons of TNT, respectively. On January  5, 2015, North Korean TV news anchors announced that they had successfully tested a "miniaturized atomic bomb", about 5 miles from the Punggye-ri nuclear site where a test was conducted in 2013. On January 6, 2016, North Korea announced that it conducted a successful test of a hydrogen bomb. The seismic event, at a magnitude of 5.1, occurred 19 kilometers (12 miles) east-northeast of Sungjibaegam. On September 9, 2016, North Korea announced another successful nuclear weapon test at the Punggye-ri Test Site. This is the first warhead the state claims to be able to mount to a  missile or long-range rocket previously tested in June 2016. Estimates for the explosive yield range from 20 to 30 kt and coincided with a 5.3 magnitude earthquake in the region. On September 3, 2017, North Korea successfully detonated its first weapon self-designated as a hydrogen bomb. Initial yield estimates place it at 100 kt. Reports indicate that the test blast caused a magnitude 6.3 earthquake, and possibly resulted in a cave-in at the test site. Alleged tests. There have been a number of significant alleged/disputed/unacknowledged accounts of countries testing nuclear explosives. Their status is either  not certain or entirely disputed by most mainstream experts. China. On April 15, 2020 U.S. officials said China may have conducted low-yield nuclear weapon tests in its Lop Nur test site. Israel. Israel was alleged by a Bundeswehr report to have made an underground test in 1963. Historian Taysir Nashif reported a zero yield implosion test in 1966. Scientists from Israel participated in the earliest French nuclear tests before DeGaulle cut off further cooperation. North Korea. On September 9, 2004, South Korean media reported that there had been a large explosion at the Chinese/North Korean border. This explosion  left a crater visible by satellite and precipitated a large (2-mile diameter) mushroom cloud. The United States and South Korea quickly downplayed this, explaining it away as a forest fire that had nothing to do with the DPRK's nuclear weapons program. North Korea has conducted six nuclear tests, in 2006, 2009, 2013, twice in 2016, and 2017. The 3 September 2017 test, like their January 2016 test, is claimed to be a hydrogen bomb (but may only be a boosted fission weapon rather than an actual staged Teller–Ulam thermonuclear weapon). Pakistan. Because Pakistan's nuclear program was  conducted under extreme secrecy, it raised concerns in the Soviet Union and India, who suspected that since the 1974 test it was inevitable that Pakistan would further develop its program. The pro-Soviet newspaper, "The Patriot", reported that "Pakistan has exploded a nuclear device in the range of 20 to 50 kilotons" in 1983. But it was widely dismissed by Western diplomats as it was pointed out that "The Patriot" had previously engaged in spreading disinformation on several occasions. In 1983, India and the Soviet Union both investigated secret tests but, due to lack of any scientific data, these statements  were widely dismissed. In their book, "The Nuclear Express", authors Thomas Reed and Danny Stillman also allege that the People's Republic of China allowed Pakistan to detonate a nuclear weapon at its Lop Nur test site in 1990, eight years before Pakistan held its first official weapons test. However, senior scientist Abdul Qadeer Khan strongly rejected the claim in May 1998. According to Khan, due to its sensitivity, no country allows another country to use their test site to explode the devices. Such an agreement only existed between the United States and the United Kingdom since the 1958 US –UK Mutual Defense Agreement which among other things allows Britain access to the American Nevada National Security Site for testing. Dr. Samar Mubarakmand, another senior scientist, also confirmed Dr. Khan's statement and acknowledged that cold tests were carried out, under codename "Kirana-I", in a test site which was built by the Corps of Engineers under the guidance of the PAEC. Additionally, the UK conducted nuclear tests in Australia in the 1950s. Russia. The Yekaterinburg Fireball of November 14, 2014, is alleged by some to have been a nuclear test in space, which would not have been detected by  the CTBTO because the CTBTO does not have autonomous ways to monitor space nuclear tests (i.e. satellites) and relies thus on information that member States would accept to provide. The fireball happened a few days before a conference in Yekaterinburg on the theme of air/missile defense. The affirmation, however, is disputed as the Russian Ministry of Emergency Situations claimed it was an "on-ground" explosion. "The Siberian Times", a local newspaper, noted that "the light was not accompanied by any sound". Vela Incident. The Vela Incident was an unidentified" double flash" of light detected by a partly functional, decommissioned  American Vela Satellite on September 22, 1979, in the Indian Ocean (near the Prince Edward Islands off Antarctica), other sensors which could have recorded proof of a nuclear test were not functioning on this satellite. It is possible that this was produced by a nuclear device. If this flash detection was actually a nuclear test, a popular theory favored in the diary of then sitting American President Jimmy Carter, is that it resulted from a covert joint South African and Israeli nuclear test of an advanced highly miniaturized Israeli artillery shell sized device which was unintentionally detectable by satellite optical  sensor due to a break in the cloud cover of a typhoon. Analysis of the South African nuclear program later showed only six of the crudest and heavy designs weighing well over 340 kg had been built when they finally declared and disarmed their nuclear arsenal. The 1986 Vanunu leaks analyzed by nuclear weapon miniaturization pioneer Ted Taylor revealed very sophisticated miniaturized Israeli designs among the evidence presented. Also suspected were France testing a neutron bomb near their Kerguelen Islands territory, the Soviet Union making a prohibited atmospheric test, as well as India or Pakistan doing initial proof of concept  tests of early weaponized nuclear bombs. Tests of live warheads on rockets. Missiles and nuclear warheads have usually been tested separately because testing them together is considered highly dangerous; they are certainly the most extreme type of live fire exercise. The only US live test of an operational missile was the following: Other live tests with the nuclear explosive delivered by rocket by the USA include: The USA also conducted two live weapons test involving nuclear artillery including: The USA also conducted one live weapons test involving a missile launched nuclear depth charge: The Soviet Union tested nuclear explosives on  rockets as part of their development of a localized anti-ballistic missile system in the 1960s. Some of the Soviet nuclear tests with warheads delivered by rocket include: The Soviet Union also conducted three live nuclear torpedo tests including: The People's Republic of China conducted CHIC-4 with a Dongfeng-2 rocket launch on October 25, 1966. The warhead exploded with a yield of 12 kt. Most powerful tests. The following list contains all known nuclear tests conducted with a yield of 1.4 Mt TNT equivalent and more.