Atomic Testing


The nuclear weapons tests of the United States were performed from 1945 to 1992 as part of the nuclear arms race. The United States conducted around 1,054 nuclear tests by official count, including 216 atmospheric, underwater, and space tests. Most of the tests took place at the Nevada Test Site (NNSS/NTS) and the Pacific Proving Grounds in the Marshall Islands and off Kiritimati Island in the Pacific, plus three in the Atlantic Ocean. Ten other tests took place at various locations in the United States, including Alaska, Nevada other than the NNSS/NTS, Colorado, Mississippi, and New Mexico. (via Wikipedia)

Nevada [☢1004]
(via Wikipedia)

The Nevada National Security Site, known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles northwest of the city of Las Vegas.

Formerly known as the Nevada Proving Grounds, the site was established in 1951 for the testing of nuclear devices. It covers approximately 1,360 square miles of desert and mountainous terrain. Nuclear weapons testing at the site began with a 1-kiloton-of-TNT bomb dropped on Frenchman Flat on January 27, 1951. Over the subsequent four decades, over 1,000 nuclear explosions were detonated at the site. Many of the iconic images of the nuclear era come from the site.

During the 1950s, the mushroom clouds from the 100 atmospheric tests could be seen from almost 100 miles away. The city of Las Vegas experienced noticeable seismic effects, and the mushroom clouds, which could be seen from the downtown hotels, became tourist attractions. Westerly winds routinely carried the fallout from above-ground nuclear testing directly through St. George, Utah and southern Utah. Increases in cancers, such as leukemia, lymphoma, thyroid cancer, breast cancer, melanoma, bone cancer, brain tumors, and gastrointestinal tract cancers, were reported from the mid-1950s onward. A further 828 nuclear tests were carried out underground.

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Marshall Islands [☢67]
(via Wikipedia)

Nuclear testing at Bikini Atoll consisted of the detonation of 23 nuclear weapons by the United States between 1946 and 1958 on Bikini Atoll in the Marshall Islands. Tests occurred at 7 test sites on the reef itself, on the sea, in the air, and underwater. The test weapons produced a combined fission yield of 42.2 Mt of TNT in explosive power.

The United States and its allies were engaged in a Cold War nuclear arms race with the Soviet Union to build more advanced bombs from 1947 until 1991. The first series of tests over Bikini Atoll in July 1946 was codenamed Operation Crossroads. Able was dropped from an aircraft and detonated 520 ft above the target fleet. The second, Baker, was suspended under a barge. It produced a large Wilson cloud and contaminated all of the target ships. Chemist Glenn T. Seaborg, the longest-serving chairman of the Atomic Energy Commission, called the second test "the world's first nuclear disaster."

The second series of tests in 1954 was codenamed Operation Castle. The first detonation was Castle Bravo, which tested a new design utilizing a dry-fuel thermonuclear bomb. It was detonated at dawn on March 1, 1954. Scientists miscalculated: the 15 Mt of TNT nuclear explosion far exceeded the expected yield of 4–8 Mt of TNT. This was about 1,000 times more powerful than either of the atomic bombs dropped on Hiroshima and Nagasaki during World War II. The scientists and military authorities were shocked by the size of the explosion, and many of the instruments that they had put in place to evaluate the effectiveness of the weapon were destroyed.

Authorities had promised the Bikini Atoll's residents that they would be able to return home after the nuclear tests. A majority of the island's family heads agreed to leave the island, and most of the residents were moved to the Rongerik Atoll and later to Kili Island. Both locations proved unsuitable to sustaining life, and the United States had to provide residents with on-going aid. Despite the promises made by authorities, these and further nuclear tests rendered Bikini unfit for habitation, contaminating the soil and water, making subsistence farming and fishing too dangerous. The United States later paid the islanders and their descendants $125 million in compensation for damage caused by the nuclear testing program and their displacement from their home island. A 2016 investigation found radiation levels on Bikini Atoll as high as 639 mrem yr−1, well above the established safety standard for habitation.

After the end of World War II, Enewetak came under the control of the United States as part of the Trust Territory of the Pacific Islands, until the independence of the Marshall Islands in 1986. During its tenure, the United States evacuated the local residents many times, often involuntarily. The atoll was used for nuclear testing, as part of the Pacific Proving Grounds. Before testing commenced, the U.S. exhumed the bodies of United States servicemen killed in the Battle of Enewetak and returned them to the United States to be re-buried by their families. 43 nuclear tests were fired at Enewetak from 1948 to 1958.

The first hydrogen bomb test, code-named Ivy Mike, occurred in late 1952 as part of Operation Ivy; it vaporized the islet of Elugelab. This test included B-17 Flying Fortress drones to fly through the radioactive cloud to test onboard samples. B-17 mother ships controlled the drones while flying within visual distance of them. In all, 16 to 20 B-17s took part in this operation, of which half were controlling aircraft and half were drones. To examine the explosion clouds of the nuclear bombs in 1957/58, several rockets (mostly from rockoons) were launched. One USAF airman Jimmy Robinson was lost at sea during the tests. Robinson's F-84 Thunderjet crashed and sank 3.5 miles short of the island. Robinson's body was never recovered.

A radiological survey of Enewetak was conducted from 1972 to 1973. In 1977, the United States military began decontamination of Enewetak and other islands. During the three-year, US$100 million cleanup process, the military mixed more than 80,000 cubic meters of contaminated soil and debris from the islands with Portland cement and buried it in an atomic blast crater on the northern end of the atoll's Runit Island. The material was placed in the 9.1-meter deep, 110-meter wide crater created by the May 5, 1958, "Cactus" nuclear weapons test. A dome composed of 358 concrete panels, each 46 centimeters thick, was constructed over the material. The final cost of the cleanup project was US$239 million. The United States government declared the southern and western islands in the atoll safe for habitation in 1980, and residents of Enewetak returned that same year. The military members who participated in that cleanup mission are suffering from many health issues, but the U.S. Government is refused to provide health coverage until 2022 with the passage of the PACT Act.

Section 177 of the 1983 Compact of Free Association between the governments of the United States and the Marshall Islands establishes a process for Marshallese to make a claim against the United States government as a result of damage and injury caused by nuclear testing. That same year, an agreement was signed to implement Section 177, which established a US$150 million trust fund. The fund was intended to generate US$18 million a year, which would be payable to claimants on an agreed-upon schedule. If the US$18 million a year generated by the fund was not enough to cover claims, the principal of the fund could be used. A Marshall Islands Nuclear Claims Tribunal was established to adjudicate claims. In 2000, the tribunal made a compensation award to the people of Enewetak consisting of US$107.8 million for environmental restoration; US$244 million in damages to cover economic losses caused by loss of access and use of the atoll; and US$34 million for hardship and suffering.[30] In addition, as of the end of 2008, another US$96.658 million in individual damage awards were made. Only US$73.526 million of the individual claims award has been paid, however, and no new awards were made between the end of 2008 and May 2010. Due to stock market losses, payments rates that have outstripped fund income, and other issues, the fund was nearly exhausted, as of May 2010, and unable to make any additional awards or payments. A lawsuit by Marshallese arguing that "changed circumstances" made Nuclear Claims Tribunal unable to make just compensation was dismissed by the Supreme Court of the United States in April 2010.

The 2000 environmental restoration award included funds for additional cleanup of radioactivity on Enewetak. Rather than scrape the topsoil off, replace it with clean topsoil, and create another radioactive waste repository dome at some site on the atoll (a project estimated to cost US$947 million), most areas still contaminated on Enewetak were treated with potassium.[32] Soil that could not be effectively treated for human use was removed and used as fill for a causeway connecting the two main islands of the atoll (Enewetak and Parry). The cost of the potassium decontamination project was US$103.3 million.

A report by the US Congressional Research Service projects that the majority of the atoll will be fit for human habitation by 2026–2027, after nuclear decay, de-contamination and environmental remediation efforts create sufficient dose reductions. However, in November 2017, the Australian Broadcasting Corporation reported that rising sea levels caused by climate change are seeping inside the dome, causing radioactive material to leak out.

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Kiribati [☢26]
(via Wikipedia)

Nuclear tests were conducted on and around Kiritimati by the United Kingdom in the late 1950s, and by the United States in 1962. During these tests, the island was not evacuated, exposing the i-Kiribati residents and the British, New Zealand, and Fijian servicemen to nuclear radiation.

The entire island is a Wildlife Sanctuary; access to five particularly sensitive areas is restricted.

During the Cold War Kiritimati was used for nuclear weapons testing by the United Kingdom and the USA.

The United States also conducted 22 successful nuclear detonations over the island as part of Operation Dominic in 1962. Some toponyms (like Banana and Main Camp) come from the nuclear testing period, during which at times over 4,000 servicemen were present. By 1969, military interest in Kiritimati had ended and the facilities were mostly dismantled. However, some communications, transport, and logistics facilities were converted for civilian use, which Kiritimati uses to serve as the administrative centre for the Line Islands.

There is no reliable data on the environmental and public health impact of the nuclear tests conducted on the island in the late 1950s. A 1975 study claimed that there was negligible radiation hazard; certainly, fallout was successfully minimised. More recently however, a Massey University study of New Zealand found chromosomal translocations to be increased about threefold on average in veterans who participated in the tests; most of the relevant data remains classified to date.


The nuclear weapons tests of the Soviet Union were performed between 1949 and 1990 as part of the nuclear arms race. The Soviet Union conducted 715 nuclear tests using 969 total devices by official count, including 219 atmospheric, underwater, and space tests and 124 peaceful use tests. Most of the tests took place at the Southern Test Site in Semipalatinsk, Kazakhstan and the Northern Test Site at Novaya Zemlya. Other tests took place at various locations within the Soviet Union, including now-independent Kazakhstan, Uzbekistan, Ukraine and Turkmenistan. (via Wikipedia)

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In 1952, the United Kingdom became the third country (after the United States and the Soviet Union) to develop and test nuclear weapons, and is one of the five nuclear-weapon states under the Treaty on the Non-Proliferation of Nuclear Weapons.

The UK initiated a nuclear weapons programme, codenamed Tube Alloys, during the Second World War. At the Quebec Conference in August 1943, it was merged with the American Manhattan Project. The British contribution to the Manhattan Project saw British scientists participate in most of its work. The British government considered nuclear weapons to be a joint discovery, but the American Atomic Energy Act of 1946 (McMahon Act) restricted other countries, including the UK, from access to information about nuclear weapons. Fearing the loss of Britain's great power status, the UK resumed its own project, now codenamed High Explosive Research. On 3 October 1952, it detonated an atomic bomb in the Monte Bello Islands in Australia in Operation Hurricane. Eleven more British nuclear weapons tests in Australia were carried out over the following decade, including seven British nuclear tests at Maralinga in 1956 and 1957. (via Wikipedia)


France executed nuclear weapons tests in the areas of Reggane and In Ekker in Algeria and the Mururoa and Fangataufa Atolls in French Polynesia, from 13 February 1960 through 27 January 1996. These totaled 210 tests with 210 device explosions, 50 in the atmosphere.

(via Wikipedia)


The List of nuclear weapons tests is a listing of the Chinese nuclear tests conducted from 1964 through 1996. Most listings of the Chinese tests show 45 tests in the series with 45 devices, with 23 tests being atmospheric. (via Wikipedia)


India's nuclear test series consists of a pair of series: Pokhran I and Pokhran II. Pokhran I was a single nuclear test conducted in 1974. (via Wikipedia)


The nuclear weapons tests of Pakistan refers to a test programme directed towards the development of nuclear explosives and investigation of the effects of nuclear explosions. The programme was suggested by Munir Ahmad Khan, chairman of the Pakistan Atomic Energy Commission (PAEC), as early as 1977. The first subcritical testing was carried out in 1983 by PAEC, codenamed Kirana-I, and continued until the 1990s under the government of the Prime Minister of Pakistan, Benazir Bhutto. Further claims of conducting subcritical tests at Kahuta were made in 1984 by the Kahuta Research Laboratories but were dismissed by the Government of Pakistan.

The Pakistan Government, under Prime Minister Nawaz Sharif, authorized the programme jointly under PAEC and KRL, assisted by the Corps of Engineers in 1998. There were six nuclear tests performed under this programme, codenamed Chagai-I, and Chagai-II. After the Prime Minister of India, Atal Vajpayee made a state visit to Pakistan to meet with the Prime Minister of Pakistan, Nawaz Sharif, both countries signed a nuclear testing control treaty, the Lahore Declaration in 1999. (via Wikipedia)

Ras Koh
(via Wikipedia)

Chagai-I is the code name of five simultaneous underground nuclear tests conducted by Pakistan at 15:15 hrs PKT on 28 May 1998. The tests were performed at Ras Koh Hills in the Chagai District of Balochistan Province.

Chagai-I was Pakistan's first public test of nuclear weapons. Its timing was a direct response to India's second nuclear test Pokhran-II, on 11 and 13 May 1998. These tests by Pakistan and India resulted in United Nations Security Council Resolution 1172 and economic sanctions on both states by a number of major powers, particularly the United States and Japan. By testing nuclear devices, Pakistan became the seventh country to publicly test nuclear weapons. Pakistan's second nuclear test, Chagai-II, followed on 30 May 1998.

Safety and security required a remote, isolated and unpopulated mountainous area. The Geological Survey of Pakistan (GSP) conducted tests to select a "bone dry" mountain capable of withstanding a 20–40 kilotonne detonation from the inside. The scientists wanted dry weather, and very little wind to spread radioactive fallout. Koh Kambaran located in the Ras Koh Hills was selected in 1978. Due to widespread imprecise reporting which mentioned the Chagai Hills region prior to the actual explosion, there is sometimes geographic confusion. Both the Chagai Hills and the Ras Koh Hills are situated in the Chagai District, but the Ras Koh Hills lie to the south of Chagai Hills, and are separated from the Chagai Hills by a large valley.


North Korea has conducted six nuclear tests, in 2006, 2009, 2013, twice in 2016, and in 2017. (via Wikipedia)

Punggye-ri Nuclear Test Site
(via Wikipedia)

Punggye-ri Nuclear Test Site (풍계리 핵 실험장) was the only known nuclear test site of North Korea. Nuclear tests were conducted at the site in October 2006, May 2009, February 2013, January 2016, September 2016, and September 2017.

According to sources, people from the Punggye-ri nuclear test site have been banned from entering Pyongyang since the test due to the possibility of being radioactively contaminated. According to the report of defectors, about 80% of trees died and all of the underground wells dried up in the site after the sixth nuclear test.

On 3 and 23 September 2017, earthquakes which seem to be collapses of tunnels were detected with magnitude of 4.1 and 3.6 respectively. A 17 October 2017 study published by the US-Korea Institute at Johns Hopkins University suggested the most recent test had caused "substantial damage to the existing tunnel network under Mount Mantap". On 30 October 2017, in testimony before the South Korean parliament, the director of South Korea's Meteorological Administration warned that "further tests at Punggye-ri could cause the mountain to collapse and release radioactivity into the environment." Likewise, Chinese scientists warned that if the mountain collapsed, nuclear fallout could spread across "an entire hemisphere."[16] On 1 November 2017 Japanese TV station TV Asahi reported that according to unconfirmed reports, several tunnels collapsed at the test site on 10 October 2017. An initial collapse was said to have killed 100 workers, with another 100 rescuers killed in a second collapse.

On 20 April 2018 the North Korean government announced that it would suspend nuclear tests and shut down the Punggye-ri nuclear test site. On 14 May 2018 it was reported that commercial satellite imagery indicated that dismantling of the facilities at the test site had begun. The leader and Supreme Commander of North Korea Kim Jong-un determined the date for the closing ceremony of Punggye-ri - 23-25 May 2018. The government of North Korea allowed a handful of international journalists (but none from South Korea) to observe the closing ceremony. Notably absent would be experts or inspectors who could study the test site at close quarters.

On 24 May 2018 foreign journalists reported that tunnels in the Punggye-ri nuclear test site had been destroyed by the North Korean government in a move to reduce regional tensions. However, despite the active tunnel entrances being demolished, the tunnels themselves were not destroyed and the tunnels that were never used in testing were not part of the public demolition. Additionally, the majority of the administrative and support facilities along Punggye-ri's 17-km-long complex were not demolished, and caretaker activities have been noted as recently as 25 November 2020.