# Nuclear Testing Between 1945 and 1996, nine nations conducted over 2,000 nuclear weapon tests — detonations designed to validate weapon designs, assess effects, and demonstrate capability. The testing era left a legacy of radioactive contamination, displaced communities, long-term health consequences, and a body of knowledge that now sustains nuclear arsenals through computer simulation rather than live explosions. The politics of testing — who tests, where, and whether to ban it — interweave with every dimension of nuclear policy the vault tracks, from the [[Arms Race]] to the [[Nuclear Energy Debate]] to environmental justice. ## Testing Methods **Atmospheric testing** — detonating weapons in the open air, at the surface, or at altitude — characterized the early nuclear age. The United States conducted 216 atmospheric tests between 1945 and 1962, including the Bikini Atoll hydrogen bomb tests that contaminated the Marshall Islands and exposed the crew of the Japanese fishing vessel Lucky Dragon to lethal fallout. The [[Soviet Union]] conducted 219 atmospheric tests. The UK, France, and China also tested in the atmosphere. These tests spread Radioactivity globally — strontium-90 from fallout appeared in milk supplies worldwide, and detectable levels of carbon-14 from atmospheric testing remain in the biosphere today. **Underground testing** became the standard after the 1963 Partial Test Ban Treaty (PTBT) prohibited tests in the atmosphere, underwater, and in outer space. Underground tests contain most radioactive debris but occasionally "vent," releasing radiation to the surface. The Nevada Test Site (now the Nevada National Security Site) hosted 928 tests, 100 of them atmospheric. The Soviet Semipalatinsk site in [[Kazakhstan]] hosted 456 tests; health studies of the surrounding population have documented elevated cancer rates and birth defects spanning generations. **Subcritical testing** uses high explosives and fissile material in configurations that do not achieve a self-sustaining nuclear chain reaction. These experiments, which the United States continues at the Nevada site, provide data on weapons physics without producing a nuclear yield. The US position is that subcritical tests do not violate the Comprehensive Nuclear-Test-Ban Treaty (which the US has signed but not ratified); critics argue they undermine the treaty's spirit by allowing continued weapons development. ## Test Ban Treaties **The Partial Test Ban Treaty (PTBT, 1963)** banned nuclear tests in the atmosphere, underwater, and in outer space, though not underground. It was driven by growing public alarm over radioactive fallout — the [[Dwight D. Eisenhower]] and [[John F. Kennedy]] administrations faced increasing domestic pressure as atmospheric testing contaminated food supplies. Among the pressure groups, [[Women Strike for Peace]] — whose November 1, 1961 strike put an estimated 50,000 women in the streets over strontium-90 in children's milk — is credited in part with moving Kennedy toward the treaty. The PTBT reduced global fallout dramatically but did not slow the [[Arms Race]]; underground testing continued at high rates through the 1980s. **The Comprehensive Nuclear-Test-Ban Treaty (CTBT, 1996)** bans all nuclear explosions in all environments. It has been signed by 187 nations but has not entered into force because eight specific states must ratify it, and several — including the United States, China, Israel, Iran, and Egypt — have not. The US Senate rejected ratification in 1999; the [[George W. Bush]] administration opposed the treaty; subsequent administrations have observed a testing moratorium without ratification. The gap between US behavior (no testing since 1992) and US legal commitment (unsigned ratification) is a characteristic example of the American pattern of following norms while refusing to be bound by them. The CTBT is monitored by the International Monitoring System — a global network of 337 seismic, hydroacoustic, infrasound, and radionuclide stations that can detect nuclear explosions as small as one kiloton anywhere on Earth. North Korea's six nuclear tests (2006-2017) were all detected by this system, demonstrating its effectiveness even against a state that attempted to conceal its activities. ## Stockpile Stewardship Since the US testing moratorium began in 1992, the reliability and safety of the American nuclear arsenal have been maintained through the Stockpile Stewardship Program — a combination of supercomputer simulations, subcritical experiments, and non-nuclear component testing conducted at the national laboratories described in [[US Strategic Nuclear Weapons]]. The program uses data from the 1,054 US nuclear tests to validate computer models that predict how weapons components age and perform. Stockpile stewardship is expensive — the National Nuclear Security Administration's annual budget exceeds $20 billion — but its existence is what makes the testing moratorium politically sustainable. Weapons designers can certify that warheads remain reliable without detonating them, removing the strongest argument for resumed testing. However, some hawks argue that new warhead designs (like the W93 planned for Columbia-class submarines) cannot be fully validated without testing, creating periodic pressure to break the moratorium — a development that would shatter nonproliferation norms and invite resumed testing by [[Russia]], [[China]], and others. ## Environmental and Human Costs The testing legacy includes substantial environmental contamination and public health consequences. The Marshall Islands, site of 67 US nuclear tests including the 15-megaton Castle Bravo shot (1954), remain partially uninhabitable. Downwind communities in Nevada and Utah — "downwinders" — experienced elevated cancer rates from atmospheric fallout; Congress passed the Radiation Exposure Compensation Act in 1990 to provide partial restitution, though coverage has been contentious and repeatedly required expansion. Soviet testing at Semipalatinsk exposed an estimated 1.5 million Kazakhs to fallout. British tests in Australia contaminated Aboriginal lands at Maralinga. French tests in Algeria and French Polynesia affected local populations who had no voice in the decision to test. The pattern is consistent: nuclear testing sites were chosen in territories inhabited by politically marginalized populations — indigenous peoples, Pacific Islanders, rural communities — a fact that connects nuclear testing to broader environmental justice concerns and to the [[Military-Industrial Complex]]'s pattern of externalizing costs onto communities with limited political power. ## See Also - [[Nuclear Weapons Design]] — what tests were designed to validate - Radioactivity — the contamination tests produced - [[Cold War]] — the strategic context driving the test program - [[Arms Race]] — the competitive dynamic that accelerated testing - [[US Strategic Nuclear Weapons]] — stockpile stewardship and the modern arsenal - [[Dwight D. Eisenhower]] — early test ban negotiations - [[John F. Kennedy]] — PTBT negotiation and signing - [[George W. Bush]] — CTBT opposition - [[Russia]] — nuclear peer and testing history - [[China]] — CTBT non-ratifier - [[Military-Industrial Complex]] — institutional drivers of testing programs