Nuclear testing in the context of Trinity site

A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, though to date all fusion-based weapons have used a fission device to initiate fusion, and a pure fusion weapon remains a hypothetical device. Nuclear explosions are used in nuclear weapons and nuclear testing.

Nuclear explosions are extremely destructive compared to conventional (chemical) explosives, because of the vastly greater energy density of nuclear fuel compared to chemical explosives. They are often associated with mushroom clouds, since any large atmospheric explosion can create such a cloud. Nuclear explosions produce high levels of ionizing radiation and radioactive debris that is harmful to humans and can cause moderate to severe skin burns, eye damage, radiation sickness, radiation-induced cancer and possible death depending on how far a person is from the blast radius. Nuclear explosions can also have detrimental effects on the climate, lasting from months to years. A small-scale nuclear war could release enough particles into the atmosphere to cause the planet to cool and cause crops, animals, and agriculture to disappear across the globe—an effect named nuclear winter.

The Tsar Bomba (code name: Ivan or Vanya, internal designation "AN602") was the most powerful nuclear weapon or weapon of any kind ever constructed and tested. A project of the Soviet Union, it was a thermonuclear aerial bomb, tested on 30 October 1961 at the Novaya Zemlya site in the country's far north. The bomb yielded 50 megatons of TNT.

The Soviet physicist Andrei Sakharov oversaw the project at Arzamas-16, while the main work of design was by Sakharov, Viktor Adamsky, Yuri Babayev, Yuri Smirnov [ru], and Yuri Trutnev. The project was ordered by First Secretary of the Communist Party Nikita Khrushchev in July 1961 as part of the Soviet resumption of nuclear testing after the Test Ban Moratorium, with the detonation timed to coincide with the 22nd Congress of the Communist Party of the Soviet Union (CPSU).

Operation Argus was a series of United States low-yield, high-altitude nuclear weapons tests and missile tests secretly conducted from 27 August to 9 September 1958 over the South Atlantic Ocean. The tests were performed by the Defense Nuclear Agency.

The tests were to study the Christofilos effect, which suggested it was possible to defend against Soviet nuclear missiles by exploding a small number of nuclear bombs high over the South Pacific. This would create a disk of electrons over the United States that would overload the electronics on the Soviet warheads as they descended. It was also possible to use the effect to blind Soviet radars, meaning that any Soviet missile-based ABM system would be unable to attack the US counterstrike.

Castle Romeo was the code name given to one of the tests in the Operation Castle series of U.S. nuclear tests. It was the first test of the TX-17 thermonuclear weapon, the first deployed thermonuclear bomb.

It was detonated on 26 March 1954, at Bikini Atoll of the Marshall Islands, on a barge moored in the middle of the crater from the Castle Bravo test. It was the first such barge-based test, a necessity that had come about because the powerful thermonuclear devices obliterated the small islands following detonation.

The Armed Forces Special Weapons Project (AFSWP) was a United States military agency responsible for those aspects of nuclear weapons remaining under military control after the Manhattan Project was succeeded by the Atomic Energy Commission on 1 January 1947. These responsibilities included the maintenance, storage, surveillance, security and handling of nuclear weapons, as well as supporting nuclear testing. The AFSWP was a joint organization, staffed by the United States Army, United States Navy and United States Air Force; its chief was supported by deputies from the other two services. Major General Leslie R. Groves, the former head of the Manhattan Project, was its first chief.

The early nuclear weapons were large, complex, and cumbersome. They were stored as components rather than complete devices and required expert knowledge to assemble. The short life of their lead-acid batteries and modulated neutron initiators, and the heat generated by the fissile cores, precluded storing them assembled. The large quantity of conventional explosive in each weapon demanded special care be taken in handling. Groves hand-picked a team of regular Army officers, who were trained in the assembly and handling of the weapons. They in turn trained the enlisted soldiers, and the Army teams then trained teams from the Navy and Air Force.

North Korea is the most recent country to develop and openly test nuclear weapons. As of 2024, its arsenal comprises approximately 50 nuclear weapons and production of fissile material for six to seven nuclear weapons per year. North Korea stockpiles a significant quantity of chemical and biological weapons. North Korea is party to the Biological Weapons Convention, one of four UN members not to ratify the Chemical Weapons Convention, and the only country to announce withdrawal from the Non-Proliferation Treaty (NPT).

North Korea is the only country confirmed to conduct nuclear weapons tests in the 21st century, carrying out six underground tests at Punggye-ri from 2006 to 2017. It is believed the country developed boosted fission or thermonuclear weapons. The Korean People's Army Strategic Force operates intercontinental ballistic missiles, and shorter-range ballistic and cruise missiles, some for tactical use. North Korea is developing submarine-launched ballistic missiles. Its missile development is linked to its satellite program.