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Nuclear testing

Nuclear testing

Overview
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...

s. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them. Testing nuclear weapons can yield information about how the weapons work, as well as how the weapons behave under various conditions and how structures behave when subjected to nuclear explosions.
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Timeline

1953   Nuclear testing: At the Nevada Test Site, the United States conduct their first and only nuclear artillery test.

1954   Nuclear testing: The Castle Bravo, a 15-megaton hydrogen bomb, is detonated on Bikini Atoll in the Pacific Ocean, resulting in the worst radioactive contamination ever caused by the United States.

1957   First American underground nuclear bomb test.

1961   Nuclear testing: The Soviet Union detonates the hydrogen bomb Tsar Bomba over Novaya Zemlya; at 58 megatons of yield, it is still the largest explosive device ever detonated, nuclear or otherwise.

1964   Cold War: Indian Prime Minister Jawaharlal Nehru appeals to the United States and the Soviet Union to end nuclear testing and to start nuclear disarmament, stating that such an action would "save humanity from the ultimate disaster".

1998   India carries out two nuclear tests at Pokhran, following the three conducted on May 11. The United States and Japan impose economic sanctions on India.

1998   Nuclear testing: Pakistan responds to a series of nuclear tests by India with five of its own, prompting the United States, Japan, and other nations to impose economic sanctions.

 
Encyclopedia
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapon
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. Both reactions release vast quantities of energy from relatively small amounts of matter. The first fission bomb test released the same amount...

s. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them. Testing nuclear weapons can yield information about how the weapons work, as well as how the weapons behave under various conditions and how structures behave when subjected to nuclear explosions. Additionally, nuclear testing has often been used as an indicator of scientific and military strength, and many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status by means of a nuclear test.

The first nuclear weapon was detonated as a test by the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 at the Trinity site on July 16, 1945, with a yield approximately equivalent to 20 kilotons. The first hydrogen bomb, codenamed "Mike
Ivy Mike
Ivy Mike was the codename given to the first United States test of a thermonuclear weapon, in which a major part of the explosive yield came from nuclear fusion. It was detonated on November 1, 1952 by the United States at on Enewetak, an atoll in the Pacific Ocean, as part of Operation Ivy...

", was tested at the Enewetak
Enewetak
Enewetak Atoll is a large coral atoll of 40 islands in the Pacific Ocean, and forms a legislative district of the Ralik Chain of the Marshall Islands. Its land area totals less than , surrounding a deep central lagoon, in circumference...

 atoll in the Marshall Islands
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

 on November 1 (local date) in 1952, also by the United States. The largest nuclear weapon ever tested was the "Tsar Bomba
Tsar Bomba
Tsar Bomba is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated. It was also referred to as Kuz'kina Mat , in this usage meaning "something that has not been seen before"....

" of the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 at Novaya Zemlya
Novaya Zemlya
Novaya Zemlya , also known in Dutch as Nova Zembla and in Norwegian as , is an archipelago in the Arctic Ocean in the north of Russia and the extreme northeast of Europe, the easternmost point of Europe lying at Cape Flissingsky on the northern island...

 on October 30, 1961, with an estimated yield of around 50 megatons
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...

.

In 1963, all nuclear and many non-nuclear states signed the Limited Test Ban Treaty, pledging to refrain from testing nuclear weapons in the atmosphere, underwater, or in outer space
Outer space
Outer space is the void that exists between celestial bodies, including the Earth. It is not completely empty, but consists of a hard vacuum containing a low density of particles: predominantly a plasma of hydrogen and helium, as well as electromagnetic radiation, magnetic fields, and neutrinos....

. The treaty permitted underground nuclear testing
Underground nuclear testing
Underground nuclear testing refers to test detonations of nuclear weapons that are performed underground. When the device being tested is buried at sufficient depth, the explosion may be contained, with no release of radioactive materials to the atmosphere....

. France continued atmospheric testing until 1974, China continued up until 1980.

Underground tests in the United States continued until 1992 (its last nuclear testing), the Soviet Union in 1990, the United Kingdom in 1991, and both China and France in 1996. After signing the Comprehensive Test Ban Treaty
Comprehensive Test Ban Treaty
The Comprehensive Nuclear-Test-Ban Treaty bans all nuclear explosions in all environments, for military or civilian purposes. It was adopted by the United Nations General Assembly on 10 September 1996 but it has not entered into force.-Status:...

 in 1996 (which has as of 2011 not yet entered into force), all of these states have pledged to discontinue all nuclear testing. Non-signatories India
India and weapons of mass destruction
India possesses nuclear weapons and maintains short- and intermediate-range ballistic missiles, nuclear-capable aircraft, surface ships, and submarines under development as possible delivery systems and platforms...

 and Pakistan
Pakistan and weapons of mass destruction
Pakistan began focusing on nuclear weapons development in January 1972 under the leadership of Prime Minister Zulfiqar Ali Bhutto, who delegated the program to the Chairman of PAEC Munir Ahmad Khan...

 last tested nuclear weapons in 1998.

The most recent nuclear test
2009 North Korean nuclear test
The 2009 North Korean nuclear test was the underground detonation of a nuclear device conducted on 25 May 2009 by North Korea. This was its second nuclear test, the first test having taken place in October 2006. Following the nuclear test, Pyongyang also conducted several missile tests.The test was...

 was announced by North Korea
North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...

 on May 25, 2009.

Types



Nuclear weapons tests have historically been broken into four categories reflecting the medium or location of the test.
  • Atmospheric testing designates explosions that take place in the atmosphere
    Earth's atmosphere
    The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

    . Generally these have occurred as devices detonated on towers, balloons, barges, islands, or dropped from airplanes. Nuclear explosions that are close enough to the ground to draw dirt and debris into their mushroom cloud
    Mushroom cloud
    A mushroom cloud is a distinctive pyrocumulus mushroom-shaped cloud of condensed water vapor or debris resulting from a very large explosion. They are most commonly associated with nuclear explosions, but any sufficiently large blast will produce the same sort of effect. They can be caused by...

     can generate large amounts of nuclear fallout
    Nuclear fallout
    Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...

     due to irradiation
    Irradiation
    Irradiation is the process by which an object is exposed to radiation. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to...

     of the debris.

  • Underground testing refers to nuclear tests that are conducted under the surface of the earth, at varying depths. Underground nuclear testing
    Underground nuclear testing
    Underground nuclear testing refers to test detonations of nuclear weapons that are performed underground. When the device being tested is buried at sufficient depth, the explosion may be contained, with no release of radioactive materials to the atmosphere....

     made up the majority of nuclear tests by the United States and the Soviet Union during the Cold War
    Cold War
    The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

    ; other forms of nuclear testing were banned by the Limited Test Ban Treaty in 1963. When the explosion is fully contained, underground nuclear testing emits a negligible amount of fallout. However, underground nuclear tests can "vent" to the surface, producing considerable amounts of radioactive debris as a consequence. Underground testing can result in seismic activity depending on the yield
    Nuclear weapon yield
    The explosive yield of a nuclear weapon is the amount of energy discharged when a nuclear weapon is detonated, expressed usually in the equivalent mass of trinitrotoluene , either in kilotons or megatons , but sometimes also in terajoules...

     of the nuclear device and the composition of the medium it is detonated in, and generally result in the creation of subsidence crater
    Subsidence crater
    A subsidence crater is a hole or depression left on the surface of an area which has had an underground explosion. Many such craters are present at the Nevada Test Site, which is no longer in use for nuclear testing....

    s. In 1976, the United States and the USSR agreed to limit the maximum yield of underground tests to 150 kt with the Threshold Test Ban Treaty
    Threshold Test Ban Treaty
    The Treaty on the Limitation of Underground Nuclear Weapon Tests, also known as the Threshold Test Ban Treaty , was signed in July 1974 by the USA and the USSR...

    .

  • Exoatmospheric testing refers to nuclear tests conducted above the atmosphere. The test devices are lifted on rockets. These high altitude nuclear explosion
    High altitude nuclear explosion
    High-altitude nuclear explosions have historically been nuclear explosions which take place above altitudes of 30 km, still inside the Earth's atmosphere. Such explosions have been tests of nuclear weapons, used to determine the effects of the blast and radiation in the exoatmospheric...

    s can generate an electromagnetic pulse
    Electromagnetic pulse
    An electromagnetic pulse is a burst of electromagnetic radiation. The abrupt pulse of electromagnetic radiation usually results from certain types of high energy explosions, especially a nuclear explosion, or from a suddenly fluctuating magnetic field...

     (EMP), and charged particles resulting from the blast can cross hemispheres to create an auroral display.

  • Underwater testing results from nuclear devices being detonated underwater
    Underwater explosion
    An underwater explosion, also known as an UNDEX, is an explosion beneath the surface of water. The type of explosion may be chemical or nuclear...

    , usually moored to a ship or a barge (which is subsequently destroyed by the explosion). Tests of this nature have usually been conducted to evaluate the effects of nuclear weapons against naval vessels (such as in Operation Crossroads
    Operation Crossroads
    Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. It was the first test of a nuclear weapon after the Trinity nuclear test in July 1945...

    ), or to evaluate potential sea-based nuclear weapons (such as nuclear torpedoes or depth-charges). Underwater tests close to the surface can disperse large amounts of radioactive water and steam, contaminating nearby ships or structures.

Purpose


Separately from these designations, nuclear tests are also often categorized by the purpose of the test itself.
  • weapons related tests are designed to garner information about how (and if) the weapons themselves work. Some serve to develop and validate a specific weapon type. Others test experimental concepts or are physics experiments meant to gain fundamental knowledge of the processes and materials involved in nuclear detonations.

  • weapons effects tests are designed to gain information about the effects of the weapons on structures, equipment, organisms and the environment. They are mainly used to assess and improve survivability to nuclear explosions in civilian and military contexts, tailor weapons to their targets, and develop the tactics of nuclear warfare.

  • safety experiments are designed to study the behavior of weapons in simulated accident scenarios. In particular, they are used to verify that a (significant) nuclear detonation cannot happen by accident. They include one-point safety tests and simulations of storage and transportation accidents.

  • nuclear test detection experiments are designed to improve the capabilities to detect, locate, and identify nuclear detonations; in particular to monitor compliance with test ban treaties.

  • Peaceful nuclear explosions
    Peaceful nuclear explosions
    Peaceful nuclear explosions are nuclear explosions conducted for non-military purposes, such as activities related to economic development including the creation of canals...

    are conducted to investigate non-military applications of nuclear explosives.


Aside from these technical considerations, tests have been conducted for political and training purposes. Tests also often serve multiple purposes.

Alternatives to full-scale testing


Hydronuclear tests study nuclear materials under the conditions of explosive shock compression. They can create sub-critical conditions, or supercritical conditions with yields ranging from negligible all the way up to a substantial fraction of full weapon yield.

Critical mass experiments determine the quantity of fissile material required for criticality with a variety of fissile material compositions, densities, shapes, and reflectors
Neutron reflector
A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, and tungsten carbide, or other materials...

. They can be sub-critical or super-critical, in which case significant radiation fluxes can be produced. This type of test resulted in several criticality accident
Criticality accident
A criticality accident, sometimes referred to as an excursion or a power excursion, is an accidental increase of nuclear chain reactions in a fissile material, such as enriched uranium or plutonium...

s.

Sub-critical (or cold) tests are any type of tests involving nuclear materials and possibly high-explosives (like those mentioned above) that purposely result in no yield
Nuclear weapon yield
The explosive yield of a nuclear weapon is the amount of energy discharged when a nuclear weapon is detonated, expressed usually in the equivalent mass of trinitrotoluene , either in kilotons or megatons , but sometimes also in terajoules...

. The name refer to the lack of creation of a critical mass
Critical mass
A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties A critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The...

 of fissile material. They are the only type of tests allowed under the Comprehensive Nuclear-Test-Ban Treaty.

Additionally, there have been simulations of the effects of nuclear detonations using conventional explosives (such as the Minor Scale
Minor scale
A minor scale in Western music theory includes any scale that contains, in its tonic triad, at least three essential scale degrees: 1) the tonic , 2) a minor-third, or an interval of a minor third above the tonic, and 3) a perfect-fifth, or an interval of a perfect fifth above the tonic, altogether...

 U.S. test in 1985). The explosives might be spiked with radioactive materials to simulate fallout dispersal.

History



The first atomic weapons test was conducted near Alamogordo, New Mexico, on July 16, 1945, during the Manhattan Project
Manhattan Project
The Manhattan Project was a research and development program, led by the United States with participation from the United Kingdom and Canada, that produced the first atomic bomb during World War II. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army...

, and given the codename "Trinity
Trinity test
Trinity was the code name of the first test of a nuclear weapon. This test was conducted by the United States Army on July 16, 1945, in the Jornada del Muerto desert about 35 miles southeast of Socorro, New Mexico, at the new White Sands Proving Ground, which incorporated the Alamogordo Bombing...

". The test was originally to confirm that the implosion-type Nuclear weapon design
Nuclear weapon design
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three basic design types...

 was feasible, and to give an idea of what the actual size and effects of an atomic explosion
Effects of nuclear explosions
The energy released from a nuclear weapon detonated in the troposphere can be divided into four basic categories:*Blast—40-50% of total energy*Thermal radiation—30-50% of total energy...

 would be before they were used in combat against Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. While the test gave a good approximation of many of the explosion's effects, it did not give an appreciable understanding of Nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...

, which was not well understood by the project scientists until well after the atomic bombings of Hiroshima and Nagasaki
Atomic bombings of Hiroshima and Nagasaki
During the final stages of World War II in 1945, the United States conducted two atomic bombings against the cities of Hiroshima and Nagasaki in Japan, the first on August 6, 1945, and the second on August 9, 1945. These two events are the only use of nuclear weapons in war to date.For six months...

.

The United States conducted six atomic tests before the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 developed their first atomic bomb (RDS-1) and tested it on August 29, 1949. Neither country had very many atomic weapons to spare at first, and so testing was relatively infrequent (when the U.S. used two weapons for Operation Crossroads
Operation Crossroads
Operation Crossroads was a series of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. It was the first test of a nuclear weapon after the Trinity nuclear test in July 1945...

in 1946, they were detonating over 20% of their current arsenal). However, by the 1950s the United States had established a dedicated test site on its own territory (Nevada Test Site
Nevada Test Site
The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...

) and was also using a site in the Marshall Islands
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

 (Pacific Proving Grounds
Pacific Proving Grounds
The Pacific Proving Grounds was the name used to describe a number of sites in the Marshall Islands and a few other sites in the Pacific Ocean, used by the United States to conduct nuclear testing at various times between 1946 and 1962...

) for extensive atomic and nuclear testing.

The early tests were used primarily to discern the military effects of atomic weapons (Crossroads had involved the effect of atomic weapons on a navy, and how they functioned underwater) and to test new weapon designs. During the 1950s these included new hydrogen bomb designs, which were tested in the Pacific, and also new and improved fission weapon designs. The Soviet Union also began testing on a limited scale, primarily in Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

. During the later phases of the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

, though, both countries developed accelerated testing programs, testing many hundreds of bombs over the last half of the twentieth century.

Atomic and nuclear tests can involve many hazards. A number of these were illustrated in the U.S. Castle Bravo
Castle Bravo
Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954 at Bikini Atoll, Marshall Islands, as the first test of Operation Castle. Castle Bravo was the most powerful nuclear device ever detonated by the United States ,...

 test in 1954. The weapon design tested was a new form of hydrogen bomb, and the scientists underestimated how vigorously some of the weapon materials would react. As a result, the explosion with a yield of 15 Mt
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...

was over twice what was predicted. Aside from this problem, the weapon also generated a large amount of radioactive nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...

, more than had been anticipated, and a change in the weather pattern caused the fallout to be spread in a direction which had not been cleared in advance. The fallout plume spread high levels of radiation for over a hundred miles, contaminating a number of populated islands in nearby atoll formations (though they were soon evacuated, many of the islands' inhabitants suffered from radiation burns and later from other effects such as increased cancer rate and birth defects), as well as a Japanese fishing boat (Daigo Fukuryū Maru
Daigo Fukuryu Maru
was a Japanese tuna fishing boat, which was exposed to and contaminated by nuclear fallout from the United States' Castle Bravo thermonuclear device test on Bikini Atoll, on 1 March 1954....

). One member of the boat's crew died from radiation sickness after returning to port, and it was feared that the radioactive fish they had been carrying had made it into the Japanese food supply.

Bravo was the worst U.S. nuclear accident, but many of its component problems unpredictably large yields, changing weather patterns, unexpected fallout contamination of populations and the food supply occurred during other atmospheric nuclear weapons tests by other countries as well. Concerns over worldwide fallout rates eventually led to the Partial Test Ban Treaty
Partial Test Ban Treaty
The treaty banning nuclear weapon tests in the atmosphere, in outer space and under water, often abbreviated as the Partial Test Ban Treaty , Limited Test Ban Treaty , or Nuclear Test Ban Treaty is a treaty prohibiting all test detonations of nuclear weapons...

 in 1963, which limited signatories to underground testing. Not all countries stopped atmospheric testing, but because the United States and the Soviet Union were responsible for roughly 86% of all nuclear tests their compliance cut the overall level substantially. France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 continued atmospheric testing until 1974, and People's Republic of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

 until 1980.

Almost all new nuclear powers have announced their possession of nuclear weapons with a nuclear test. The only acknowledged nuclear power which claims never to have conducted a test was South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 (see Vela Incident
Vela Incident
The Vela Incident was an unidentified "double flash" of light that was detected by an American Vela Hotel satellite on September 22, 1979....

), which has since dismantled all of its weapons. Israel
Israel
The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

 is widely thought to possess a sizeable nuclear arsenal, though it has never tested, unless they were involved in Vela. Experts disagree on whether states can have reliable nuclear arsenals especially ones using advanced warhead designs, such as hydrogen bombs and miniaturized weapons without testing, though all agree that it is very unlikely to develop significant nuclear innovations without testing. One other approach is to use supercomputer
Supercomputer
A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...

s to conduct "virtual" testing, but codes need to be validated against test data.

Some nuclear tests have been for peaceful purposes. These peaceful nuclear explosions
Peaceful nuclear explosions
Peaceful nuclear explosions are nuclear explosions conducted for non-military purposes, such as activities related to economic development including the creation of canals...

 were used to evaluate whether nuclear explosions could be used for non-military purposes such as digging canals and artificial harbors, or to stimulate oil and gas fields. The tests were eventually abandoned for economic, political, and environmental reasons.

Nuclear testing has also been used for clearly political purposes. The most explicit example of this was the detonation of the largest nuclear bomb ever created, the 50 megaton Tsar Bomba
Tsar Bomba
Tsar Bomba is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated. It was also referred to as Kuz'kina Mat , in this usage meaning "something that has not been seen before"....

, by the Soviet Union in 1961. This weapon was too large to be practically used against an enemy target, and it is not thought that any were manufactured except the one detonated in the test.

There have been many attempts to limit the number and size of nuclear tests; the most far-reaching was the Comprehensive Test Ban Treaty
Comprehensive Test Ban Treaty
The Comprehensive Nuclear-Test-Ban Treaty bans all nuclear explosions in all environments, for military or civilian purposes. It was adopted by the United Nations General Assembly on 10 September 1996 but it has not entered into force.-Status:...

 of 1996, which was not ratified by the United States. Nuclear testing has since become a controversial issue in the United States, with a number of politicians saying that future testing might be necessary to maintain the aging warheads from the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

. Because nuclear testing is seen as furthering nuclear arms development, many are also opposed to future testing as an acceleration of the arms race.

Nuclear testing by country


The nuclear powers have conducted more than 2,000 nuclear test explosions (numbers are approximated, as some test results have been disputed):

United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

: 1,054 tests by official count (involving at least 1,151 devices, 331 atmospheric tests), most at Nevada Test Site
Nevada Test Site
The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...

 and the Pacific Proving Grounds
Pacific Proving Grounds
The Pacific Proving Grounds was the name used to describe a number of sites in the Marshall Islands and a few other sites in the Pacific Ocean, used by the United States to conduct nuclear testing at various times between 1946 and 1962...

 in the Marshall Islands
Marshall Islands
The Republic of the Marshall Islands , , is a Micronesian nation of atolls and islands in the middle of the Pacific Ocean, just west of the International Date Line and just north of the Equator. As of July 2011 the population was 67,182...

, with 10 other tests taking place at various locations in the United States, including Amchitka
Amchitka
Amchitka is a volcanic, tectonically unstable island in the Rat Islands group of the Aleutian Islands in southwest Alaska. It is part of the Alaska Maritime National Wildlife Refuge. The island is about long, and from wide...

 Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

, Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...

, Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

, and New Mexico
New Mexico
New Mexico is a state located in the southwest and western regions of the United States. New Mexico is also usually considered one of the Mountain States. With a population density of 16 per square mile, New Mexico is the sixth-most sparsely inhabited U.S...

 (see Nuclear weapons and the United States
Nuclear weapons and the United States
The United States was the first country to develop nuclear weapons, and is the only country to have used them in warfare, with the separate bombings of Hiroshima and Nagasaki in World War II. Before and during the Cold War it conducted over a thousand nuclear tests and developed many long-range...

 for details). Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

: 715 tests (involving 969 devices) by official count, most at Semipalatinsk Test Site
Semipalatinsk Test Site
The Semipalatinsk Test Site was the primary testing venue for the Soviet Union's nuclear weapons. It is located on the steppe in northeast Kazakhstan , south of the valley of the Irtysh River...

 and Novaya Zemlya
Novaya Zemlya
Novaya Zemlya , also known in Dutch as Nova Zembla and in Norwegian as , is an archipelago in the Arctic Ocean in the north of Russia and the extreme northeast of Europe, the easternmost point of Europe lying at Cape Flissingsky on the northern island...

, and a few more at various sites in Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

, Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...

, Turkmenistan
Turkmenistan
Turkmenistan , formerly also known as Turkmenia is one of the Turkic states in Central Asia. Until 1991, it was a constituent republic of the Soviet Union, the Turkmen Soviet Socialist Republic . Turkmenistan is one of the six independent Turkic states...

, and Ukraine
Ukraine
Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...

. France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

: 210 tests by official count (50 atmospheric, 160 underground), four atomic atmospheric tests at C.E.S.M. near Reggane
Reggane
Reggane from berber argan is a town in the Adrar Province of central Algeria, in the Sahara Desert. It is the southernmost town of the Tuat....

, 13 atomic underground tests at C.E.M.O. near In Ekker in the then-French Algeria
Algeria
Algeria , officially the People's Democratic Republic of Algeria , also formally referred to as the Democratic and Popular Republic of Algeria, is a country in the Maghreb region of Northwest Africa with Algiers as its capital.In terms of land area, it is the largest country in Africa and the Arab...

n Sahara
Sahara
The Sahara is the world's second largest desert, after Antarctica. At over , it covers most of Northern Africa, making it almost as large as Europe or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean...

, and nuclear atmospheric tests at Fangataufa
Fangataufa
Fangataufa is a small, low, narrow, coral atoll in the eastern side of the Tuamotu Archipelago. Along with its neighboring atoll, Moruroa, it has been the site of approximately 200 nuclear bomb tests....

 and nuclear undersea tests Moruroa
Moruroa
Moruroa , also historically known as Aopuni, is an atoll which forms part of the Tuamotu Archipelago in French Polynesia in the southern Pacific Ocean...

 in French Polynesia
French Polynesia
French Polynesia is an overseas country of the French Republic . It is made up of several groups of Polynesian islands, the most famous island being Tahiti in the Society Islands group, which is also the most populous island and the seat of the capital of the territory...

. Additional atomic and chemical warfare tests took place in the secret base B2-Namous, near Ben Wenif, other tests involving rockets and missiles at C.I.E.E.S, near Hammaguir
Hammaguir
Hammaguir is a town in Algeria, south-west of Béchar. Between 1947 and 1967 there was a rocket launch site near Hammaguir, used by France for launching sounding rockets and the satellite carrier "Diamant" between 1965 and 1967....

, both in the Sahara. United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

: 45 tests (21 in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

n territory, including nine in mainland South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

 at Maralinga
British nuclear tests at Maralinga
British nuclear tests at Maralinga occurred between 1955 and 1963 at the Maralinga site, part of the Woomera Prohibited Area, in South Australia. A total of seven major nuclear tests were performed, with approximate yields ranging from 1 to 27 kilotons of TNT equivalent...

 and Emu Field, some at Christmas Island
Kiritimati
Kiritimati or Christmas Island is a Pacific Ocean raised coral atoll in the northern Line Islands, and part of the Republic of Kiribati....

 in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

, plus many others in the United States as part of joint test series) China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

: 45 tests (23 atmospheric and 22 underground, at Lop Nur
Lop Nur
Lop Lake or Lop Nur is a group of small, now seasonal salt lake sand marshes between the Taklamakan and Kuruktag deserts in the Bayingolin Mongol Autonomous Prefecture, southeastern portion of Xinjiang Uygur Autonomous Region in the People's Republic of China.The lake system into which the Tarim...

 Nuclear Weapons Test Base, in Malan
Malan
-People:*César Malan*David Malan*Lucio Malan , Italian politician*Solomon Caesar Malan*William Gerald Malan, Missouri bankerMembers of the prominent South African Malan family:*F. S...

, Xinjiang
Xinjiang
Xinjiang is an autonomous region of the People's Republic of China. It is the largest Chinese administrative division and spans over 1.6 million km2...

) India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

: Six underground tests (including the first one in 1974), at Pokhran
Pokhran
Pokhran is a city and a municipality located in Jaisalmer district in the Indian state of Rajasthan. It is a remote location in the Thar Desert region and served as the test site for India's first underground nuclear weapon detonation.-Geography:Pokhran http://marupradesh.org/ located at...

. Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

: Six underground tests, at Ras Koh Hills, Chagai District
Chagai District
Chaghi/Chagai is the largest district of Pakistan and is located on the north west corner of Balochistan, Pakistan. It forms a triangular border with Afghanistan and Iran.Pakistan conducted a nuclear weapons test in 1998 at Ras Koh Hills Chagai District....

 and Kharan Desert
Kharan Desert
The Kharan Desert is a sand desert situated in the Balochistan province of Pakistan.Kharan desert is Pakistan's second nuclear test site, and the second nuclear test — Codename Chagai-II — was conducted and supervised by the Pakistan Atomic Energy Commission in May 30, 1998.The desert is...

, Kharan District
Kharan District
Kharan is a district in the north-west of Balochistan province of Pakistan. Kharan was notified as a district in 1951 and the Deputy Commissioner’s office started functioning on March 15, 1952. The Deputy Commissioner directly supervises all activities in the district and the functions of all...

 in Balochistan Province. North Korea
North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...

: two tests at Hwadae-ri
2006 North Korean nuclear test
The 2006 North Korean nuclear test was the detonation of a nuclear device conducted on October 9, 2006 by North Korea.North Korea announced its intention to conduct a test on October 3, six days prior, and in doing so became the first nation to give warning of its first nuclear test...

.

Additionally, there may have been at least three alleged but unacknowledged nuclear explosions (see list of alleged nuclear tests). Of these, the only one taken seriously as a possible nuclear test is the Vela Incident
Vela Incident
The Vela Incident was an unidentified "double flash" of light that was detected by an American Vela Hotel satellite on September 22, 1979....

, a possible detection of a nuclear explosion in the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...

 in 1979.

From the first nuclear test in 1945 until tests by Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

 in 1998, there was never a period of more than 22 months with no nuclear testing. June 1998 to October 2006 was the longest period since 1945 with no acknowledged nuclear tests.


Compensation for victims


Over 500 atmospheric nuclear weapons tests were conducted at various sites around the world from 1945 to 1980. As public awareness and concern mounted over the possible health hazards associated with exposure to the nuclear fallout
Nuclear fallout
Fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and shock wave have passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes...

, various studies were done to assess the extent of the hazard. A Centers for Disease Control and Prevention
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention are a United States federal agency under the Department of Health and Human Services headquartered in Druid Hills, unincorporated DeKalb County, Georgia, in Greater Atlanta...

/ National Cancer Institute
National Cancer Institute
The National Cancer Institute is part of the National Institutes of Health , which is one of 11 agencies that are part of the U.S. Department of Health and Human Services. The NCI coordinates the U.S...

 study claims that nuclear fallout might have led to approximately 11,000 excess deaths, most caused by thyroid cancer
Thyroid cancer
Thyroid neoplasm is a neoplasm or tumor of the thyroid. It can be a benign tumor such as thyroid adenoma, or it can be a malignant neoplasm , such as papillary, follicular, medullary or anaplastic thyroid cancer. Most patients are 25 to 65 years of age when first diagnosed; women are more affected...

 linked to exposure to iodine-131
Iodine-131
Iodine-131 , also called radioiodine , is an important radioisotope of iodine. It has a radioactive decay half-life of about eight days. Its uses are mostly medical and pharmaceutical...

.
  • United States: As of March 2009, the U.S. is the only nation that compensates nuclear test victims. Since the Radiation Exposure Compensation Act
    Radiation Exposure Compensation Act
    The United States Radiation Exposure Compensation Act is a federal statute providing for the monetary compensation of people, including atomic veterans, who contracted cancer and a number of other specified diseases as a direct result of their exposure to atmospheric nuclear testing undertaken by...

     of 1990, more than $1.38 billion in compensation has been approved. The money is going to people who took part in the tests, notably at the Nevada Test Site
    Nevada Test Site
    The Nevada National Security Site , previously the Nevada Test Site , is a United States Department of Energy reservation located in southeastern Nye County, Nevada, about northwest of the city of Las Vegas...

    , and to others exposed to the radiation.

  • France: In March 2009, the French Government offered to compensate victims for the first time and legislation is being drafted which would allow payments to people who suffered health problems related to the tests. The payouts would be available to victims' descendants and would include Algerians, who were exposed to nuclear testing in the Sahara in 1960. However, victims say the eligibility requirements for compensation are too narrow.

  • Britain: There is no formal British government compensation program. However, nearly 1,000 veterans of Christmas Island nuclear tests in the 1950s are planning to sue the Ministry of Defense for negligence. They say they suffered health problems and were not warned of potential dangers before the experiments.

  • Russia: Decades later, Russia offered compensation to veterans who were part of the 1954 Totsk test. However, there was no compensation to civilians sickened by the Totsk test. Anti-nuclear groups say there has been no government compensation for other nuclear tests.

  • China: China has undertaken highly secretive atomic tests in remote deserts in a Central Asian border province. Anti-nuclear activists say there is no known government program for compensating victims.

See also


  • Atomic Testing Museum
    Atomic Testing Museum
    The Atomic Testing Museum in Las Vegas, Nevada, documents the history of nuclear testing at the Nevada Test Site in the desert north of Las Vegas.-Founding:The museum opened in March 2005...

     (in Nevada in the US)
  • Effects of nuclear explosions
    Effects of nuclear explosions
    The energy released from a nuclear weapon detonated in the troposphere can be divided into four basic categories:*Blast—40-50% of total energy*Thermal radiation—30-50% of total energy...

  • High altitude nuclear explosion
    High altitude nuclear explosion
    High-altitude nuclear explosions have historically been nuclear explosions which take place above altitudes of 30 km, still inside the Earth's atmosphere. Such explosions have been tests of nuclear weapons, used to determine the effects of the blast and radiation in the exoatmospheric...

  • History of nuclear weapons
    History of nuclear weapons
    The history of nuclear weapons chronicles the development of nuclear weapons. Nuclear weapons possess enormous destructive potential derived from nuclear fission or nuclear fusion reactions...

  • List of military nuclear accidents (including nuclear weapons accidents)
  • List of nuclear tests
  • List of states with nuclear weapons
  • Live fire exercise
    Live fire exercise
    A live fire exercise or LFX is any exercise in which a realistic scenario for the use of specific equipment is simulated. In the popular lexicon this is applied primarily to tests of weapons or weapon systems that are associated with the various branches of a nation's armed forces, although the...

  • National Technical Means
  • Nuclear weapons design
  • Partial Test Ban Treaty
    Partial Test Ban Treaty
    The treaty banning nuclear weapon tests in the atmosphere, in outer space and under water, often abbreviated as the Partial Test Ban Treaty , Limited Test Ban Treaty , or Nuclear Test Ban Treaty is a treaty prohibiting all test detonations of nuclear weapons...

  • Project Gnome
    Project GNOME
    Project Gnome was the first nuclear test of the Plowshare program and was the first continental nuclear weapon test since Trinity to be conducted outside of the Nevada Test Site...

  • Test Readiness Program
    Test Readiness Program
    The Test Readiness Program was a United States Government program established in 1963 to maintain the necessary technologies and infrastructure for the atmospheric testing of nuclear weapons, should the treaty which prohibited such testing be abrogated....

  • Underwater explosion
    Underwater explosion
    An underwater explosion, also known as an UNDEX, is an explosion beneath the surface of water. The type of explosion may be chemical or nuclear...

  • :Category:Nuclear test sites
  • Trinity and Beyond
    Trinity and Beyond
    Trinity and Beyond: The Atomic Bomb Movie is a 1995 American documentary film directed by Peter Kuran and narrated by William Shatner. Using restored archive footage, the film traces the development of nuclear weapons and their testing, from America's Trinity test of 1945 to the first Chinese...

     (documentary about nuclear weapon testing)

  • External links