TheUnited States performednuclear weapons tests from 1945 to 1992 as part of thenuclear arms race. By official count, there were 1,054 nuclear tests conducted, including 215 atmospheric and underwater tests.[1][notes 1]
Most of the tests took place at theNevada Test Site (NNSS/NTS), thePacific Proving Grounds in theMarshall Islands or off Kiritimati Island in the Pacific, plus three in the Atlantic Ocean. Ten other tests took place at various locations in the United States, includingAlaska,Nevada (outside of the NNSS/NTS),Colorado,Mississippi, andNew Mexico.
| Series or years | Years covered | Tests[Summ 1] | Devices fired | Devices with unknown yield | Peaceful use tests | Non-PTBT tests[Summ 2] | Yield range(kilotons)[Summ 3] | Total yield(kilotons)[Summ 4] | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Trinity | 1945 | 1 | 1 | 1 | 21 | 21 | First nuclear weapons test, conducted as part of theManhattan Project. Tested theMark 3 Fat Man design. | ||
| Crossroads | 1946 | 2 | 2 | 2 | 21 | 42 | First postwar test series | ||
| Sandstone | 1948 | 3 | 3 | 3 | 18 to 49 | 104 | The first use of "levitated" cores made oforalloy. Tested components forMark 4 design. | ||
| Ranger | 1951 | 5 | 5 | 5 | 1 to 22 | 40 | First tests at the Nevada Test Site. Operation originally named "Operation Faust". | ||
| Greenhouse | 1951 | 4 | 4 | 4 | 46 to 225 | 398 | George shot was the firstthermonuclear device, an unweaponized physics experiment;Item shot was firstboosted fission weapon. | ||
| Buster-Jangle | 1951 | 7 | 7 | 7 | small to 31 | 72 | The first series in which troop maneuvers (Desert Rock exercises) were performed | ||
| Tumbler-Snapper | 1952 | 8 | 8 | 8 | 1 to 31 | 104 | First boosted fission weapon tests in thecontinental United States | ||
| Ivy | 1952 | 2 | 2 | 2 | 500 to 10,400 | 10,900 | Mike shot was the first multi-megaton thermonuclear weapon, first death related to nuclear testing, of sampler pilot.King shot remains largest fission weapon to not attempt boosting. | ||
| Upshot-Knothole | 1953 | 11 | 11 | 11 | small to 61 | 252 | First thermonuclear weapon tests in the continental US. 18,000 men exposed inDesert Rock V up to 26.6 REM. 84 exceeded current yearly limits of 5 REM/yr. | ||
| Castle | 1954 | 6 | 6 | 6 | 110 to 15,000 | 48,200 | Bravo shot inspired secretProject 4.1 to study fallout victims. It over-produced by 250% of expected yield, causing fallout over a wide area. | ||
| Teapot | 1955 | 14 | 14 | 14 | 1 to 43 | 167 | |||
| Wigwam | 1955 | 1 | 1 | 1 | 30 | 30 | 2,000 feet (610 m) underwater | ||
| Project 56 | 1955–1956 | 4 | 4 | 4 | 0 to 0 | 0 | |||
| Redwing | 1956 | 17 | 17 | 17 | small to 5,000 | 20,820 | Cherokee was first US airdrop of thermonuclear weapon,Zuni was first US test of three-stage thermonuclear weapon. First use of the "materials substitution method", aleadtamper instead of a natural uranium one. First series to set with "yield budget" of 20 Mt, and fission yield (effectively fallout) budget, ultimately releasing 10 Mt. Competition between UCRL and LASL over budget allocation was high. | ||
| Project 57 | 1957 | 1 | 1 | 1 | 0 | 0 | The first safety test, asking whether an improperly ignited bomb (as in a plane crash) would cause a nuclear blast. | ||
| Plumbbob | 1957 | 29 | 29 | 25 | 0 to 74 | 345 | Included the largest atmospheric test incontinental US, shotHood | ||
| Project 58+58A | 1957 | 4 | 4 | 1 | small to 1 | 1 | Four more safety tests | ||
| Hardtack I | 1958 | 35 | 35 | 35 | 0 to 9,300 | 35,628 | A series in the Pacific Proving Ground, including three rocket boosted high altitude tests calledOperation Newsreel | ||
| Argus | 1958 | 3 | 3 | 3 | 2 | 4 | Also known asOperation Floral before becomingArgus for security reasons. Tested three weapons in the South Atlantic, trying to create an artificial energy belt in the magnetosphere. | ||
| Hardtack II | 1958 | 37 | 37 | 24 | 0 to 22 | 46 | Meant to squeeze all possible testing into the time before Eisenhower's test ban started on 30 October 1958. Planned as "Operation Millrace", changed toHT II when a science panel recommended to "stop testing after theHardtack series." | ||
| Nougat | 1961–1962 | 44 | 44 | 1 | 2 | small to 67 | 357 | First all-underground test series. Included firstOperation Plowshare shot "Gnome" in Carlsbad, New Mexico, which was detonated in an underground salt dome. | |
| Sunbeam | 1962 | 4 | 4 | 4 | small to 2 | 2 | AkaOperation Dominic II. Test of small tactical warheads, including the man-portable "Davy Crockett". Last atmospheric test series overCONUS. The Army's part of Sunbeam wasOperation Ivy Flats. | ||
| Dominic | 1962–1963 | 31 | 31 | 31 | 2 to 9,960 | 34,640 | Frigate Bird was the only test of a live warhead on a strategic missile system, theUGM-27 Polaris. Series also included three high-altitude tests known as Operation Fishbowl, separated out in this text. | ||
| Fishbowl | 1962 | 9 | 9 | 4 | 9 | 400 to 1,400 | 2,205 | The high altitude rocket part ofOperation Dominic. Included several failed tests as the rockets failed for various reasons.Starfish Prime was the largest ever test in outer space. | |
| Storax | 1962–1963 | 47 | 47 | 3 | 1 | 1 to 115 | 585 | ||
| Roller Coaster | 1963 | 4 | 4 | 4 | 0 | 0 | Storage-transportation safety experiments; measured plutonium dispersal risk. | ||
| Niblick | 1963–1964 | 41 | 43 | 4 | small to 249 | 698 | |||
| Whetstone | 1964–1965 | 46 | 49 | 4 | 1 | small to 51 | 476 | ||
| Flintlock | 1965–1966 | 47 | 49 | 2 | small to 365 | 1,891 | |||
| Latchkey | 1966–1967 | 38 | 38 | 3 | small to 870 | 1,831 | |||
| Crosstie | 1967–1968 | 48 | 57 | 5 | 4 | 2 | small to 1,300 | 3,638 | |
| Bowline | 1968–1969 | 47 | 58 | 2 | 1 | small to 1,150 | 2,152 | ||
| Mandrel | 1969–70 | 52 | 78 | 1 | 2 | small to 1,900 | 5,528 | Mandrel was largest underground test at Nevada Test Site. | |
| Emery | 1970–1971 | 16 | 24 | 2 | small to 220 | 565 | |||
| Grommet | 1971–1972 | 34 | 39 | 1 | small to 4,800 | 5,200 | IncludedCannikin, the largest underground explosion ever at 5 Mt, fired under the Aleutian island Amchitka. | ||
| Toggle | 1972–1973 | 28 | 35 | 1 | small to 250 | 958 | |||
| Arbor | 1973–1974 | 18 | 20 | small to 150 | 274 | ||||
| Bedrock | 1974–1975 | 27 | 29 | small to 750 | 2,840 | ||||
| Anvil | 1975–1976 | 21 | 21 | 0 to 1,000 | 5,993 | ||||
| Fulcrum | 1976–1977 | 21 | 24 | small to 140 | 635 | ||||
| Cresset | 1977–1978 | 22 | 23 | 0 to 150 | 1,122 | ||||
| Quicksilver | 1978–1979 | 16 | 16 | 1 to 140 | 717 | ||||
| Tinderbox | 1979–1980 | 14 | 14 | 1 to 140 | 452 | ||||
| Guardian | 1980–1981 | 14 | 14 | 1 to 140 | 322 | ||||
| Praetorian | 1981–1982 | 19 | 20 | 1 to 140 | 938 | ||||
| Phalanx | 1982–1983 | 18 | 19 | 1 to 143 | 365 | ||||
| Fusileer | 1983–1984 | 16 | 16 | small to 150 | 521 | ||||
| Grenadier | 1984–1985 | 16 | 16 | 3 to 150 | 670 | ||||
| Charioteer | 1985–1986 | 16 | 16 | small to 140 | 549 | ||||
| Musketeer | 1986–1987 | 14 | 16 | 3 to 150 | 970 | ||||
| Touchstone | 1987–1988 | 13 | 15 | 2 to 150 | 696 | ||||
| Cornerstone | 1988–1989 | 11 | 17 | 1 to 150 | 436 | ||||
| Aqueduct | 1989–1990 | 10 | 13 | small to 150 | 426 | ||||
| Sculpin | 1990–1991 | 7 | 9 | 2 to 140 | 478 | ||||
| Julin | 1991–1992 | 7 | 9 | small to 100 | 172 | The last test series, cut off by the negotiation of theComprehensive Test Ban Treaty | |||
| Totals | 1945-Jul-16 to 1992-Sep-23 | 1032 | 1132 | 12 | 27 | 231 | 0 to 15,000 | 196,552 | Total country yield is 36.3% of all nuclear testing. |
Graphical timeline of United States atmospheric nuclear weapons tests[1]
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