List of nuclear weapons tests

Totals 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. 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 fission and 328 Mt from 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.

Known tests

In the following subsections, a selection of significant tests (by no means exhaustive) are listed, representative of the testing effort in each nuclear country.

United States of America

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:

The Trinity test on 16 July 1945, was the first-ever test of a nuclear weapon (yield of around 20 kilotons).

The Operation Crossroads series in July 1946, was the first postwar test series and one of the largest military operations in U.S. history.

The Operation Greenhouse shots of May 1951 included the first boosted fission weapon test ("Item") and a scientific test which proved the feasibility of thermonuclear weapons (George).

The Ivy Mike shot of 1 November 1952, was the first full test of a Teller-Ulam design "staged" hydrogen bomb, with a yield of 10 megatons. This was not a deployable weapon: With its full cryogenic equipment it weighed about 82 tons.

The Castle Bravo shot of 1 March 1954, was the first test of a deployable (solid fuel) thermonuclear weapon, and also (accidentally) the largest weapon ever tested by the United States (15 megatons). It was also the single largest U.S. radiological accident in connection with nuclear testing. The unanticipated yield, and a change in the weather, resulted in nuclear fallout spreading eastward onto the inhabited Rongelap and Rongerik atolls, which were soon evacuated. Many of the Marshall Islands natives have since suffered from birth defects and have received some compensation from the federal government. A Japanese fishing boat, the Fifth Lucky Dragon, also came into contact with the fallout, which caused many of the crew to grow ill; one eventually died. The crew's exposure was referenced in the film Godzilla as a criticism of American nuclear tests in the Pacific.

Shot Argus I of Operation Argus, on 27 August 1958, was the first detonation of a nuclear weapon in outer space when a 1.7-kiloton warhead was detonated at 200 kilometers' altitude during a series of high-altitude nuclear explosions.

Shot Frigate Bird of Operation Dominic on 6 May 1962, was the only U.S. test of an operational ballistic missile with a live nuclear warhead (yield of 600 kilotons), at Kiritimati (formerly Christmas Island) in the Pacific. In general, missile systems were tested without live warheads and warheads were tested separately for safety concerns. In the early 1960s there were mounting questions about how the systems would behave under combat conditions (when they were "mated", in military parlance), and this test was meant to dispel these concerns. However, the warhead had to be somewhat modified before its use, and the missile was only a SLBM (and not an ICBM), so by itself it did not satisfy all concerns.

Shot Sedan of Operation Storax on 6 July 1962 (yield of 104 kilotons), was an attempt at showing the feasibility of using nuclear weapons for civilian, peaceful purposes as part of Operation Plowshare. In this instance, a 1280-feet-in-diameter and 320-feet-deep explosion crater, morphologically similar to an impact crater, was created at the Nevada Test Site.

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:

Operation First Lightning/RDS-1 (known as Joe 1 in the West), August 29, 1949: first Soviet nuclear test.

RDS-6s (known as Joe 4 in the West), August 12, 1953: first Soviet thermonuclear test using a sloika (layer cake) design. The design proved to be unscalable into megaton yields, but it was air-deployable.

RDS-37, November 22, 1955: first Soviet multi-megaton, "true" hydrogen bomb test using Andrei Sakharov's "third idea", essentially a re-invention of the Teller-Ulam.

Tsar Bomba, October 30, 1961: largest nuclear weapon ever detonated, with a design yield of 100 Mt, de-rated to 50 Mt for the test drop.

Chagan, January 15, 1965: large cratering experiment as part of Nuclear Explosions for the National Economy program, which created an artificial lake.

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 (21 in Australian territory, including 9 in mainland South Australia at Maralinga and Emu Field, 3 at Malden Island and 6 at Kiritibati (Christmas Island) in the Line Islands of the central Pacific, 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:

Operation Hurricane, October 3, 1952 (first atomic bomb)

Operation Totem, 1953

Operation Mosaic, 1956

Operation Buffalo, 1956

Operation Antler, 1957

Operation Grapple, 1957–1958 (Included the first hydrogen bomb, Grapple X/Round C)

Last test: Julin Bristol, November 26, 1991, vertical shaft.

Atmospheric tests involving nuclear material but conventional explosions:

Operation Kittens, 1953-1961 (initiator tests using conventional explosive)

Operation Rats, 1956-1960 (conventional explosions to study dispersal of uranium)

Operation Tims, 1955-1963 (conventional explosions for tamper, plutonium compression trials)

Operation Vixen, 1959-1963 (effects of accidental fire or explosion on nuclear weapons)

France

France conducted 210 nuclear tests between February 13, 1960 and January 27, 1996. Four were tested at Reggane, 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.

Operation Gerboise bleue, February 13, 1960 (first atomic bomb) and three more: Reggane, Algeria; in the atmosphere; final test reputed to be more intended to prevent the weapon from falling into the hands of generals rebelling against French colonial rule than for testing purposes.

Operation Agathe, November 7, 1961 and 12 more: In Ekker, Algeria; underground

Operation Aldébaran, July 2, 1966 and 45 more: Moruroa and Fangataufa; in the atmosphere;

Canopus first hydrogen bomb: August 28, 1968 (Fangataufa)

Operation Achille June 5, 1975 and 146 more: Moruroa and Fangataufa; underground

Operation Xouthos last test: January 27, 1996 (Fangataufa)

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)

596 First test - October 16, 1964

Test No. 6, First hydrogen bomb test - June 17, 1967

CHIC-16, 200 kt-1 Mt atmospheric test - June 17, 1974

#29, Last atmospheric test - October 16, 1980. This would also be the last atmospheric nuclear test by any other country

#45, Last test - July 29, 1996, underground.

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.

May 18, 1974: Operation Smiling Buddha (type: implosion, plutonium and underground). One underground test in a horizontal shaft around 107 m long under the long-constructed Indian Army Pokhran Test Range (IA-PTR) in the Thar Desert, eastern border of Pakistan. The Indian Meteorological Department and the Atomic Energy Commission announced the yield of the weapon at 12 kt. Other Western sources claimed the yield to be around 2–12 kt. However, the claim was dismissed by the Bulletin of the Atomic Scientists and it was later reported to be 8 kt.

May 11, 1998: Operation Shakti (type: implosion, 3 uranium and 2 plutonium devices, all underground). The Atomic Energy Commission (AEC) of India and the Defence Research and Development Organisation (DRDO) simultaneously conducted a test of three nuclear devices at the Indian Army Pokhran Test Range (IAPTR) on May 11, 1998. Two days later, on May 13, the AEC and DRDO carried out a test of two further nuclear devices, detonated simultaneously. During this operation, AEC India claimed to have tested a three-stage thermonuclear device (Teller-Ulam design), but the yield of the tests was significantly lower than that expected from thermonuclear devices. The yields remain questionable, at best, by Western and Indian scholars, estimated at 20kt-45kt.

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.

March 11, 1983: Kirana-I (type: implosion, non-fissioned (plutonium) and underground). The 24 underground cold tests of nuclear devices were performed near the Sargodha Air Force Base.

May 28, 1998: Chagai-I (type: implosion, HEU and underground). One underground horizontal-shaft tunnel test (inside a granite mountain) of boosted fission devices at Koh Kambaran in the Ras Koh Hills in Chagai District of Balochistan Province. The announced yield of the five devices was a total of 40–45 kilotonnes with the largest having a yield of approximately 30–45 kilotonnes. An independent assessment however put the test yield at no more than 12 kt and the maximum yield of a single device at only 9 kt as opposed to 35 kt as claimed by Pakistani authorities. According to The Bulletin of the Atomic Scientists, the maximum yield was only 2–10 kt as opposed to the claim of 35 kt and the total yield of all tests was no more than 8–15 kt.

May 30, 1998: Chagai-II (type: implosion, plutonium device and underground). One underground vertical-shaft tunnel test of a miniaturized fission device having an announced yield of approximately 18–20 kilotonnes, carried out in the Kharan Desert in Kharan District, Balochistan Province. An independent assessment put the figure of this test at 4–6 kt only. Some Western seismologists put the figure at a mere 2 kt.

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. There was a 4.2 magnitude tremor 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 13 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 - 30 kt and coincided with a 5.3 magnitude earthquake in the region.

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.

Israel / South Africa

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.

Pakistan

Because Pakistan's nuclear programme 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 programme. 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 Dr. 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.

North Korea

On September 9, 2004, it was reported by South Korean media 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.

Russia

The Yekaterinburg Fireball of November 14, 2014 is alleged by some to be 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 defence. 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".

Germany

Hitlers Bombe, a book published in German by the historian Rainer Karlsch in 2005, has alleged that there is evidence that Nazi Germany performed some sort of test of a "nuclear device" (a hybrid fusion device unlike any modern nuclear weapons), allegedly on 4 March 1945 near the Ohrdruf concentration camp, though the evidence for this has not yet been confirmed, and has been doubted by many historians.

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:

Frigate Bird: on May 6, 1962, a UGM-27 Polaris A-2 missile with a live 600 kt W47 warhead was launched from the USS Ethan Allen; it flew 190 km (120 mi), re-entered the atmosphere, and detonated at an altitude of 3.4 km (2.1 mi) over the South Pacific. The test was part of Operation Dominic I. Because the weapon was substantially modified before the test and because it flew a low-trajectory, low-range profile, the test was not deemed to have been as effective at dispelling doubt about the readiness and effectiveness of rocket-powered nuclear missiles as it was hoped to be.

Other live tests with the nuclear explosive delivered by rocket by the USA include:

On August 1, 1958, Redstone rocket launched nuclear test Teak that detonated at an altitude of 77.8 km (48.3 mi). On August 12, 1958, Redstone #CC51 launched nuclear test Orange to a detonation altitude of 43 km (27 mi). Both were part of Operation Hardtack I and had a yield of 3.75 Mt

Operation Argus: three tests above the South Atlantic Ocean, August 27, August 30, and September 6, 1958

On July 9, 1962, Thor missile launched a Mk4 reentry vehicle containing a W49 thermonuclear warhead to an altitude of 248 miles (400 km). The warhead detonated with a yield of 1.45 Mt. This was the Starfish Prime event of nuclear test operation Dominic-Fishbowl

In the Dominic-Fishbowl series in 1962: Checkmate, Bluegill, Kingfish and Tightrope

The 1957 test Plumbbob/John fired a small yield nuclear weapon on a Genie air-to-air rocket from a jet fighter.

The Soviet Union tested nuclear explosives on rockets as part of their development of a localised anti-ballistic missile system in the 1960s. Some of the Soviet nuclear tests with warheads delivered by rocket include:

Baikal (USSR Test #25, February 2, 1956, at Aralsk) - one test, with a R-5M rocket launch from Kapustin Yar; fizzled.

ZUR-215 (#34, January 19, 1957, at Kapustin Yar) - one test, with a rocket launch from Kapustin Yar.

(#82 and 83, early November 1958) two tests, done after declared cease fire for test moratorium negotiations, from Kapustin Yar.

Groza (#88, September 6, 1961, at Kapustin Yar) - one test, with a rocket launch from Kapustin Yar.

Grom (#115, October 6, 1961, at Kapustin Yar) - one test, with a rocket launch from Kapustin Yar.

Volga (#106 and 108, September 20–22, 1961, at Novaya Zemlya) - two tests, with R-11M rockets launch from Rogachevo.

Roza (#94 and 99, September 12–16, 1961, at Novaya Zemlya) - two tests, with R-12 rockets launch from Vorkuta.

Raduga (#121, October 20, 1961, at Novaya Zemlya) - one test, with a R-13 rocket launch.

Tyulpan (#164, September 8, 1962, at Novaya Zemlya) - one test, with R-14 rockets launched from Chita.

Operation K (1961 and 1962, at Sary-Shagan) - five tests, at high altitude, with rockets launched from Kapustin Yar.

The People's Republic of China conducted CHIC-4 with a Dongfeng-2 rocket launch in October 27, 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 10 Mt TNT equivalent and more.