140 articles
Medium Atomic Demolition Munition
The Medium Atomic Demolition Munition was an American tactical nuclear land mine using the W45 warhead, with a selectable yield of 1 to 15 kilotons.
MOPP (protective gear)
MOPP (Mission Oriented Protective Posture) is the US military system of five graduated levels of chemical and biological protective gear, ranging from MOPP 0 to full encapsulation at MOPP 4.
Nerve agent
A nerve agent, also called nerve gas, is an organophosphorus chemical warfare agent that kills by inhibiting acetylcholinesterase; agents include sarin, tabun, soman, and VX.
Neutron bomb
The neutron bomb, formally an enhanced radiation weapon (ERW), is a low-yield thermonuclear warhead conceived by Samuel T. Cohen in 1958 that kills through neutron radiation rather than blast.
Neutron generator
A neutron generator is a small accelerator that produces neutrons by fusing hydrogen isotopes, used in oil well logging, elemental analysis, security screening, and nuclear weapons.
Neutron initiator
A neutron initiator is a device that emits a burst of neutrons to start the fission chain reaction in a nuclear weapon, timed to when the core is most compressed.
Nevada Test Site
The Nevada Test Site, renamed the Nevada National Security Site in 2010, is a Department of Energy installation in southern Nevada that hosted 928 nuclear tests from 1951 to 1992.
North Korea and weapons of mass destruction
North Korea (DPRK) possesses nuclear weapons, an assessed large chemical weapons stockpile, and a suspected biological weapons capability, having conducted six nuclear tests between 2006 and 2017.
Novichok (Новичок)
Novichok (Новичок, "newcomer") is a group of organophosphorus nerve agents developed in a secret Soviet program, used in the 2018 Salisbury poisonings in England and against Alexei Navalny in 2020.
Nuclear explosion
A nuclear explosion releases enormous energy almost instantly from splitting or joining atomic nuclei, first demonstrated in the Trinity test in New Mexico in 1945.
Nuclear football
The nuclear football, officially the Presidential Emergency Satchel, is a briefcase of nuclear war plans carried by a military aide so the US president can authorize a strike anywhere.
Nuclear gravity bomb
A nuclear gravity bomb is a nuclear weapon dropped from an aircraft and falling under gravity without propulsion, in US service as the B61 family since 1968.
Nuclear holocaust
A nuclear holocaust is the destruction of human civilization by large-scale nuclear war. It has never occurred; Hiroshima and Nagasaki in 1945 remain the only wartime use.
Nuclear testing at Bikini Atoll
Nuclear testing at Bikini Atoll was the series of 23 US nuclear weapon tests conducted in the Marshall Islands between 1946 and 1958, including the Castle Bravo detonation.
Nuclear weapon design
Nuclear weapon design is the engineering discipline of arranging fissile material, explosives, and fusion fuel so a chain reaction releases nuclear energy within a fraction of a second.
Nuclear weapon yield
Nuclear weapon yield is the total energy released in a nuclear explosion, expressed as equivalent TNT tonnage, and ranges from tens of tons in small devices to megatons in thermonuclear weapons.
Nuclear weapons and Israel
Israel's nuclear program, centered on the Dimona reactor built with French help in the late 1950s, produced about 90 warheads it has never confirmed or denied, with no nuclear test.
Nuclear weapons of the United Kingdom
The nuclear weapons of the United Kingdom are a Trident submarine arsenal run by the Royal Navy as a continuous at-sea deterrent since 1969, first tested in 1952.
Nuclear weapons of the United States
The nuclear weapons of the United States form one of the world's two largest arsenals, first built under the Manhattan Project and used against Hiroshima and Nagasaki in 1945.
Nuclear weapons testing
Nuclear weapons testing is the controlled detonation of nuclear explosive devices to assess weapon performance and effects, first done by the United States at Trinity in 1945.
Nunn–Lugar Cooperative Threat Reduction Program
The Nunn–Lugar Cooperative Threat Reduction Program is a US Defense Department effort created by Congress in 1991 that funds the dismantlement of Soviet weapons of mass destruction.
Operation Castle
Operation Castle was a 1954 US series of six thermonuclear test detonations at Bikini and Enewetak atolls, ranging from 110 kilotons to 15 megatons in yield.
Operation Crossroads
Operation Crossroads was a pair of 1946 nuclear tests at Bikini Atoll testing atomic bomb effects on warships; the underwater Baker shot sank nine ships.
Operation Fishbowl
Operation Fishbowl was the US Department of Defense's 1962 high-altitude nuclear test series in the Johnston Island area, part of Operation Dominic I, with five rocket-launched shots.
Operation Grapple
Operation Grapple was a series of nine British nuclear weapons tests in 1957 and 1958 at Malden and Christmas Islands in the Pacific, proving Britain's hydrogen bomb.
Operation Hardtack I
Operation Hardtack I was a series of 35 United States nuclear tests at Enewetak, Bikini, and Johnston Island in 1958, totaling 35.6 megatons, the largest US test series to that date.
Operation Sea-Spray
Operation Sea-Spray was a secret 1950 U.S. Navy test in which a ship sprayed bacteria into the air off San Francisco, exposing about 800,000 residents without their consent.
Operation Teapot
Operation Teapot was a 1955 United States nuclear test series of 14 nuclear shots and one non-nuclear shot at the Nevada Test Site, engaging about 11,000 Defense Department personnel.
Operation Upshot–Knothole
Operation Upshot–Knothole was a 1953 series of 11 atmospheric nuclear tests at the Nevada Proving Ground, involving about 21,000 personnel and notable for heavy fallout, especially from the Harry shot.
Oralloy
Oralloy, from "Oak Ridge alloy," is a Manhattan Project code name for uranium enriched to about 93.5 percent uranium-235, the fuel of the Little Boy bomb dropped on Hiroshima.