Nuclear weapon

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A nuclear weapon is a weapon that suddenly releases the energy in the nucleus of certain types of atoms. When triggered, these devices release a huge amount of energy in the form of a nuclear explosion.

Nuclear explosions can destroy a city and kill everyone in it. They also make radiation that make people very ill. Nuclear weapons are the most damaging weapons.

The first nuclear weapons were built by the United States during World War II. Two nuclear weapons were used to attack Japan. This is the only time when nuclear weapons were used in combat.

Today, the United States and Russia have the most nuclear weapons. The other countries that have nuclear weapons are: China, France, United Kingdom, India, Israel, North Korea, and Pakistan.

There are two ways to make nuclear weapons: fission weapons (also called atomic bombs or A-Bomb) and fusion weapons (also called hydrogen bombs, H-Bomb or thermonuclear weapons). The way they make energy for the nuclear explosion is different. Fusion weapons make bigger explosions. Fission weapons use a special isotope of uranium or plutonium. Fusion weapons use a special isotope of hydrogen.

Nuclear explosion test in Nevada in 1953.

History[change | change source]

In the years after 1895, people studying physics begin to understand how atoms are made. In the years near 1915, people have the idea that breaking special atoms can make big quantities of energy and can be used to make a bomb.

In 1939, people studying physics understand the theory of nuclear fission weapons, but no country knows how to build one. When World War II starts, Germany, the United Kingdom and the United States want to build nuclear weapons. Germany cannot build them because many of the best people studying physics have run away from Germany after Nazi rule started. The United Kingdom starts work in 1939, but the cost is so big that they stop it in 1942. In 1942, the United States start a very big program to build nuclear weapons. It continues the work done in the United Kingdom. The program is called "Manhattan Project".

The Manhattan Project has to find solutions to two difficulties. The first difficulty is how to make the special isotopes of uranium or plutonium. This process is called separation and is very slow. The United States builds very big buildings with machines for separation, but can make special isotopes for only a few nuclear weapons. The second difficulty is how to make a bomb that will produce a big nuclear explosion every time. A weapon with a broken design will often make a much smaller nuclear explosion. This is called a "fizzle". In July 1945, the Manhattan Project has solutions to the two difficulties and makes the first nuclear explosion. This test of a nuclear weapon is called "Trinity" and is a success.

In August 1945, the Manhattan Project has build two more nuclear fission weapons. The bombs are used by the United States to attack the cities of Hiroshima and Nagasaki in Japan. People from the Manhattan Project guess that 105,000 people are killed and 94,000 are hurt on the days of the attacks.[1] Medical people later guess that more than 225,000 people died if you add people who die because they were hurt when the bombs exploded.[2] Japan surrenders (stops fighting) less than one month after the first attack on Hiroshima.

After World War II, the Soviet Union wants to build nuclear weapons too.

British Nuclear Tests Veterans Association memorial in Leicester.

How do nuclear weapons work?[change | change source]

Some nuclear weapons make explosions by breaking many atoms very quickly. This is called nuclear fission. The material that explodes is a special form of uranium or plutonium. Bombs that use nuclear fission are called atomic bombs. Other nuclear weapons make even bigger explosions by pushing many small atoms together very quickly. This is called nuclear fusion. The material that explodes is a special form of hydrogen. Bombs that use nuclear fusion are called hydrogen bombs or thermonuclear bombs.

Nuclear weapons are made from the elements uranium or plutonium. Certain forms of these elements can be made to undergo nuclear fission and have a nuclear chain reaction. This produces a very large amount of energy and radiation, and will kill any people or animals within several kilometers. Much of the radiation is X-rays, which heats air to produce a huge nuclear fireball. The rapid expansion of the fireball produces a dangerous shock wave that destroys houses or buildings even several kilometers away. It will eventually kill people farther away than several kilometers depending on how much radiation the person received. The mutations in the DNA cause cancer and radiation poisoning. Nuclear bombs release fallout, which is nuclear material and dust that has been irradiated and became radioactive. This poisonous dust is blown by the winds for tens or hundreds of kilometers, and can remain dangerous for several years.

A hydrogen bomb, or fusion bomb, is a nuclear weapon which utilizes hydrogen isotopes (deuterium and tritium) as another type of fuel. Hydrogen bombs can be many hundreds of times more powerful than fission bombs. Despite the name, in hydrogen bombs in use, the hydrogen is only there to produce enough neutrons to also detonate a casing made of natural uranium. The fuel in hydrogen bombs is thus mostly unrefined uranium.

Making Nuclear Weapons[change | change source]

Nuclear weapons are hard to build because the special isotopes of uranium or plutonium are rare and hard to make. Few countries have nuclear weapons. When more countries get them this is called nuclear proliferation.

Getting nuclear weapons to the enemy[change | change source]

Getting a nuclear weapon to its target can be as difficult as making one. A nuclear explosive device can be placed in a bomb or artillery shell, or into a missile, which is called a nuclear missile. Nuclear missiles can be carried by aircraft, submarines, or trucks, or they can be placed into underground missile silos. Strategic bomber aircraft like the B-36 Peacemaker, B-52 Stratofortress and B-2 Spirit are used to carry nuclear weapons.

They are also carried by missiles, such as intercontinental ballistic missiles (ICBM), or submarine-launched ballistic missiles (SLBM's). Some missiles travel to the border of space, and then launch a number of separate nuclear weapons back toward the ground, and each one can travel to a different target. This is called a MIRV Warhead, or Multiple Independent Reentry Vehicles. Very large nuclear bombs have been produced, but in practice a MIRV can produce as much damage from several smaller explosions.

Nuclear weapons cost a lot of money to make, because the materials they are made of are very rare and it takes many scientists to make them. But many countries have managed to create nuclear weapons and many have them today. In the order that they first made nuclear weapons, they are: United States (1945), Russia (1949), United Kingdom (1952), France (1960), China (1964), India (1974), and Pakistan (1998). Many other countries are thought to have nuclear weapons secretly or to be trying to make them. Some countries formerly had them but say they have given them up. The spread of nuclear weapons is called nuclear proliferation.

Some countries have lost nuclear weapons while transporting them. There are 92 atom bombs lost at sea from all countries that have them. The bombs were lost in 15 different cases.[3][4][5] However, there could be more lost bombs.

Nuclear explosions to date[change | change source]

This is a list is of the main nuclear explosions which have happened. As well as the atomic bombings of Hiroshima and Nagasaki, the first nuclear test of a given weapon type for a country is included, and tests which were otherwise notable (such as the largest test ever). All yields (explosive power) are given in their estimated energy equivalents in kilotons of TNT.

Date Name Yield (kT) Country Significance
1945-07-16 Trinity 18–20 USA First fission device test, first plutonium implosion detonation
1945-08-06 Little Boy 12–18 USA Bombing of Hiroshima, Japan, first detonation of an enriched uranium gun-type device, first use of a nuclear device in military combat.
1945-08-09 Fat Man 18–23 USA Bombing of Nagasaki, Japan, second and last use of a nuclear device in military combat.
1949-08-29 RDS-1 22 USSR First fission weapon test by the USSR
1952-10-03 Hurricane 25 UK First fission weapon test by the UK
1952-11-01 Ivy Mike 10,400 USA First cryogenic fusion fuel "staged" thermonuclear weapon, primarily a test device and not weaponized
1952-11-16 Ivy King 500 USA Largest pure-fission weapon ever tested
1953-08-12 Joe 4 400 USSR First fusion weapon test by the USSR (not "staged")
1954-03-01 Castle Bravo 15,000 USA First dry fusion fuel "staged" thermonuclear weapon; a serious nuclear fallout accident occurred; largest nuclear detonation conducted by United States
1955-11-22 RDS-37 1,600 USSR First "staged" thermonuclear weapon test by the USSR (deployable)
1957-11-08 Grapple X 1,800 UK First (successful) "staged" thermonuclear weapon test by the UK
1957-05-31 Orange Herald 720 UK Largest boosted fission weapon ever tested. Intended as a fallback "in megaton range" in case British thermonuclear development failed.
1960-02-13 Gerboise Bleue 70 France First fission weapon test by France
1961-10-31 Tsar Bomba 57,000 USSR Largest thermonuclear weapon ever tested—scaled down from its initial 100 Mt design by 50%
1964-10-16 596 22 PR China First fission weapon test by the People's Republic of China
1967-06-17 Test No. 6 3,300 PR China First "staged" thermonuclear weapon test by the People's Republic of China
1968-08-24 Canopus 2,600 France First "staged" thermonuclear weapon test by France
1974-05-18 Smiling Buddha 12 India First fission nuclear explosive test by India
1998-05-11 Pokhran-II 60[6] India First potential fusion/boosted weapon test by India; first deployable fission weapon test by India
1998-05-28 Chagai-I 40[7] Pakistan First fission weapon (boosted) test by Pakistan
1998-05-30 Chagai-II 20[7] Pakistan Second fission weapon (boosted) test by Pakistan
2006-10-09 2006 North Korean nuclear test ~1 North Korea First fission plutonium-based device tested by North Korea; likely resulted as a fizzle
2009-05-25 2009 North Korean nuclear test 2-6 North Korea First successful fission device tested by North Korea
2013-02-16 2013 North Korean nuclear test 7 North Korea Last nuclear test from Earth

Compensation for victims[change | change source]

Over 500 atmospheric nuclear weapons tests were done at various sites around the world from 1945 to 1980. As public awareness and concern grew over the possible health hazards associated with exposure to nuclear fallout, various studies were done. A Centers for Disease Control and Prevention study says that nuclear fallout might have led to 11,000 excess deaths, most caused by thyroid cancer linked to exposure to iodine-131.[8]

People associated with nuclear weapons[change | change source]

Notable individuals who have been associated with nuclear weapons and related issues include:[9][10][11][12][13]

References[change | change source]

  1. The Atomic Bombings of Hiroshima and Nagasaki: Total Casualties from the Atomic Archive, retrieved on 27 December 2014.
  2. Hiroshima and Nagasaki Death Toll from Children of the Atomic Bomb, retrieved on 27 December 2014.
  3. "Map of 15 Known Lost Nuclear Bombs". 2011 [last update]. Retrieved August 31, 2011.
  4. "About Facts Net". 2005 [last update]. Retrieved August 31, 2011. "92"
  5. "Lost nuclear bombs". 2011 [last update]. Retrieved August 31, 2011. "92"
  6. [2010 test] Kakodkar says Pokhran-II tests fully successful], 24 September 2009
  7. 7.0 7.1 Pakistan Nuclear Weapons. Federation of American Scientists. December 11, 2002
  8. Exposure of the American Population to Radioactive Fallout from Nuclear Weapons Tests
  9. Brown, Jerry and Rinaldo Brutoco (1997). Profiles in Power: The Anti-nuclear Movement and the Dawn of the Solar Age, Twayne Publishers.
  10. Ben Goddard (2010-01-27). "Cold Warriors say no nukes". The Hill.
  11. Ancient Rockers Try to Recharge Anti-Nuclear Movement Business & Media Institute, November 8, 2007.
  12. Falk, Jim (1982). Gobal Fission:The Battle Over Nuclear Power, p. 95.
  13. Renee Parsons (2012-04-16). "No Nukes and Intervening Women". Huffington Post.

Other websites[change | change source]

Wikimedia Commons has media related to: Use of nuclear weapons