A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions In nuclear physics and nuclear chemistry, a nuclear reaction is the process in which two nuclei or nuclear particles collide to produce products different from the initial particles. In principle a reaction can involve more than three particles colliding, but because the probability of three or more nuclei to meet at the same time at the same, either fission In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons (in the form of gamma rays), as well. Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation or a combination of fission and fusion In nuclear physics and nuclear chemistry, nuclear fusion is the process by which multiple atomic nuclei join together to form a single heavier nucleus. It is accompanied by the release or absorption of energy. Large scale fusion processes, involving many atoms fusing at once, must occur in matter which is at very high densities. Both reactions release vast quantities of energy from relatively small amounts of matter; a modern thermonuclear weapon weighing little more than a thousand kilograms can produce an explosion comparable to the detonation of more than a billion kilograms of conventional high explosive.[1]

Thus, even single small nuclear devices no larger than traditional bombs can devastate an entire city by blast, fire and radiation In physics, radiation describes a process in which energetic particles or waves, travel through a medium or space. There are two distinct types of radiation, ionizing and non-ionizing. The word radiation is commonly used in reference to ionizing radiation only , but it may also refer to non-ionizing radiation (i.e., radio waves, visible light). Nuclear weapons are considered weapons of mass destruction A weapon of mass destruction is a weapon that can kill large numbers of humans (and other life forms) and/or cause great damage to man-made structures (e.g. buildings), natural structures (e.g. mountains), or the biosphere in general. The scope and application of the term has evolved and been disputed, often signifying more politically than, and their use and control Nuclear proliferation is a term now used to describe the spread of nuclear weapons, fissile material, and weapons-applicable nuclear technology and information, to nations which are not recognized as "Nuclear Weapon States" by the Treaty on the Nonproliferation of Nuclear Weapons, also known as the Nuclear Nonproliferation Treaty or NPT has been a major focus of international relations International relations or International studies (IS) represents the study of foreign affairs and global issues among states within the international system, including the roles of states, inter-governmental organizations (IGOs), non-governmental organizations (NGOs), international nongovernmental organizations (INGOs), and multinational policy since their debut.

In the history of warfare, only two nuclear weapons During the final stages of World War II in 1945, the United States conducted two atomic bombings against Japan in the cities of Hiroshima and Nagasaki have been detonated offensively, both near the end of World War II Albania · Australia · Austria · Azerbaijan · Belarus · Belgium · Brazil · Bulgaria · Burma · Cambodia · Canada · Ceylon (Sri Lanka) · Channel Islands · China · Czechoslovakia · Denmark · Dutch East Indies · Egypt · Estonia · Finland · France · Germany · Gibraltar · Greece · Greenland · Hong Kong · Hungary · Iceland ·. The first was detonated on the morning of 6 August 1945, when the United States ^ b. English is the de facto language of American government and the sole language spoken at home by 80% of Americans age five and older. Spanish is the second most commonly spoken language dropped a uranium Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, in which 6 of the electrons are valence electrons. The uranium nucleus binds between 141 and 146 neutrons, establishing six isotopes, the most gun-type device code-named "Little Boy "Little Boy" was the codename of the atomic bomb dropped on Hiroshima on August 6, 1945 by the Boeing B-29 Superfortress Enola Gay, piloted by Colonel Paul Tibbets of the 393d Bombardment Squadron, Heavy, of the United States Army Air Forces. It was the first atomic bomb to be used as a weapon. The second, the "Fat Man", was" on the Japanese Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters that make up Japan's name mean "sun-origin", which is why Japan is city of Hiroshima Hiroshima ( listen (help·info)) is the capital of Hiroshima Prefecture, and the largest city in the Chūgoku region of western Honshū, the largest island of Japan. It became the first city in history destroyed by a nuclear weapon when the United States of America dropped an atomic bomb on it at 8:15am on August 6, 1945, near the end of World War. The second was detonated three days later when the United States dropped a plutonium Plutonium is a synthetic transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-white appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, implosion-type device code-named "Fat Man "Fat Man" is the codename for the atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9, 1945, at 10:47 PM . It was the second of the only two nuclear weapons to be used in warfare to date, and its detonation caused the third man-made nuclear explosion. The name also refers more generically to the early" on the city of Nagasaki, Japan Nagasaki ( listen (help·info)) is the capital and the largest city of Nagasaki Prefecture on the island of Kyūshū in Japan. Nagasaki was founded by the Portuguese in the 16th century. It was formerly part of Nishisonogi District. It was a center of Portuguese and European influence in the 16th through 19th centuries. Nagasaki was home to a. These bombings A bomb is any of a range of explosive devices that only rely on the exothermic mortality chemical reaction of an explosive material to provide an extremely sudden and violent release of explosion. Detonations inflict damage principally through ground- and atmosphere-transmitted mechanical stress, the impact and penetration of pressure-driven resulted in the immediate deaths of an estimated 80,000 people (mostly civilians) from injuries sustained from the explosion. When factoring in deaths from long-term effects of ionizing radiation Ionizing radiation consists of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them. The occurrence of ionization depends on the energy of the impinging individual particles or waves, and not on their number. An intense flood of particles or waves will not cause and acute radiation sickness Radiation poisoning, also called radiation sickness or a creeping dose, is a form of damage to organ tissue caused by excessive exposure to ionizing radiation. The term is generally used to refer to acute problems caused by a large dosage of radiation in a short period, though this also has occurred with long term exposure. The clinical name for, the total death toll is estimated at 120,000. The use of these weapons remains controversial.

Since the Hiroshima and Nagasaki bombings, nuclear weapons have been detonated on over two thousand occasions for testing purposes Nuclear weapons tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the twentieth century, most nations that have developed nuclear weapons have tested them. Testing nuclear weapons can yield information about how the weapons work, as well as how the weapons behave under and demonstration purposes. A few states Nations that are known or believed to possess nuclear weapons are sometimes referred to as the nuclear club. There are currently nine states that have successfully detonated nuclear weapons. Five are considered to be "nuclear weapons states" , an internationally recognized status conferred by the Nuclear Non-Proliferation Treaty (NPT) have possessed such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons—and that acknowledge possessing such weapons—are (chronologically) the United States The United States possesses and has used weapons of mass destruction. During its recent history the U.S. possessed three types of weapons of mass destruction: nuclear weapons, chemical weapons and biological weapons. The U.S. is the only country to have used nuclear weapons in combat. The U.S. also used chemical weapons in World War I, and in, the Soviet Union The Union of Soviet Socialist Republics was a constitutionally socialist state that existed in Eurasia from 1922 to 1991. The name is a translation of the Russian: Союз Советских Социалистических Республик (help·info), tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik, IPA [sɐˈjʊs sɐˈvʲeʦkʲɪx səʦɪ (succeeded as a nuclear power by Russia Russia possesses the largest stockpiles of weapons of mass destruction in the world. The country declared an arsenal of 28,000 tons of chemical weapons in 2008. According to the Nuclear Notebook, Russia had 5,200 nuclear weapons deployed in early 2008, making its stockpile the largest in the world. Other sources, such as Alexander Khramchikhin, an), the United Kingdom The United Kingdom has possessed weapons of mass destruction, including nuclear, biological, and chemical weapons. The United Kingdom is one of the five official nuclear weapon states under the Nuclear Non-Proliferation Treaty and has an independent nuclear deterrent. The U.K. has been estimated to have a stockpile of approximately 160 active, France France is known to have an arsenal of weapons of mass destruction. France is one of the five "Nuclear Weapons States" under the Nuclear Non-Proliferation Treaty; but is not known to possess or develop any chemical or biological weapons. France was the fourth country to test an independently developed nuclear weapon in 1960, under the, the People's Republic of China The People's Republic of China has developed and possessed weapons of mass destruction, including chemical and nuclear weapons. China is estimated by the Federation of American Scientists to have an arsenal of about 180 active nuclear weapon warheads and 240 total warheads as of 2009, which would make it the fourth largest nuclear arsenal amongst, India India possesses an arsenal of nuclear weapons and maintains short- and intermediate-range ballistic missiles, nuclear-capable aircraft, surface ships, and submarines under development as possible delivery systems and platforms. Although it lacks an operational ballistic missile submarines India has ambitions of possessing a nuclear triad in the, Pakistan Pakistan began focusing on nuclear development in January 1972 under the leadership of Prime Minister Zulfiqar Ali Bhutto, who delegated the program to nuclear scientists Munir Ahmad Khan, Abdul Qadeer Khan and military administrator Zahid Ali Akbar Khan under the program called Project-706. This program would reach fruition under President, and North Korea North Korea is claimed to have an arsenal of weapons of mass destruction, and claims to possess nuclear weapons. The CIA asserts that North Korea also has a substantial arsenal of chemical weapons. North Korea was a member of the Nuclear Non-Proliferation Treaty but withdrew in 2003, citing the failure of the United States to fulfill its end of. Israel Israel is widely believed to possess weapons of mass destruction, and to be one of four nuclear-armed countries not recognized as a Nuclear Weapons State by the Nuclear Non-Proliferation Treaty . The US Congress Office of Technology Assessment has recorded Israel as a country generally reported as having undeclared chemical warfare capabilities, is also widely believed to possess nuclear weapons, though it does not acknowledge having them.[2]

Contents

Types of nuclear weapons

The two basic fission In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons (in the form of gamma rays), as well. Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation weapon designs Main article: Nuclear weapon design Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three basic design types. In all three, the explosive energy of deployed devices has been derived primarily from nuclear fission, not fusion

There are two basic types of nuclear weapon. The first type produces its explosive energy through nuclear fission In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons (in the form of gamma rays), as well. Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation reactions alone. Such fission weapons are commonly referred to as atomic bombs or atom bombs (abbreviated as A-bombs), though their energy comes specifically from the nucleus of the atom.

In fission weapons, a mass of fissile In nuclear engineering, a fissile material is one that is capable of sustaining a chain reaction of nuclear fission material (enriched uranium Enriched uranium is a kind of uranium in which the percent composition of uranium-235 has been increased through the process of isotope separation. Natural uranium is 99.284% 238U isotope, with 235U only constituting about 0.711% of its weight. 235U is the only isotope existing in nature that is fissile with thermal neutrons or plutonium Plutonium is a synthetic transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-white appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens,) is assembled into a supercritical mass Critical Mass is a bicycling event typically held on the last Friday of every month in over 300 cities around the world. While the ride was originally founded in 1992 in San Francisco with the idea of drawing attention to how unfriendly the city was to cyclists, the leaderless structure of Critical Mass makes it impossible to assign it any one—the amount of material needed to start an exponentially growing Exponential growth occurs when the growth rate of a mathematical function is proportional to the function's current value. In the case of a discrete domain of definition with equal intervals it is also called geometric growth or geometric decay (the function values form a geometric progression) nuclear chain reaction A nuclear chain reaction occurs when one nuclear reaction causes an average of one or more nuclear reactions, thus leading to a self-propagating number of these reactions. The specific nuclear reaction may be the fission of heavy isotopes or the fusion of light isotopes (e.g. 2H and 3H). The nuclear chain reaction is unique since it releases—either by shooting one piece of sub-critical material into another (the "gun" method) or by compressing a sub-critical sphere of material using chemical explosives An explosive material, also called an explosive, is a substance that contains a great amount of stored energy that can produce an explosion, a sudden expansion of the material after initiation, usually accompanied by the production of light, heat, and pressure. An explosive charge is a measured quantity of explosive material to many times its original density (the "implosion" method). The latter approach is considered more sophisticated than the former and only the latter approach can be used if the fissile material is plutonium.

A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself. The amount of energy released by fission bombs can range from the equivalent of less than a ton of TNT Trinitrotoluene , or more specifically, 2,4,6-trinitrotoluene, is a chemical compound with the formula C6H2(NO2)3CH3. This yellow-colored solid is sometimes used as a reagent in chemical synthesis, but it is best known as a useful explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard upwards of 500,000 tons (500 kilotons TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 giga ) of TNT.[3]

The second basic type of nuclear weapon produces a large amount of its energy through nuclear fusion In nuclear physics and nuclear chemistry, nuclear fusion is the process by which multiple atomic nuclei join together to form a single heavier nucleus. It is accompanied by the release or absorption of energy. Large scale fusion processes, involving many atoms fusing at once, must occur in matter which is at very high densities reactions. Such fusion weapons are generally referred to as thermonuclear weapons or more colloquially as hydrogen bombs (abbreviated as H-bombs), as they rely on fusion reactions between isotopes of hydrogen Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of 1.00794 u (1.007825 u for Hydrogen-1), hydrogen is the lightest and most abundant chemical element, constituting roughly 75 % of the Universe's elemental mass. Stars in the main sequence are mainly composed of hydrogen in its (deuterium Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6,500 of hydrogen . Deuterium thus accounts for approximately 0.0154% (alternately, on a mass basis: 0.0308%) of all naturally occurring hydrogen in the oceans on Earth (see VSMOW; the abundance and tritium Tritium is a radioactive isotope of hydrogen. The nucleus of tritium (sometimes called a triton) contains one proton and two neutrons, whereas the nucleus of protium (the most abundant hydrogen isotope) contains one proton and no neutrons. Naturally occurring tritium is extremely rare on Earth. The isotope name is formed from the Greek "). However, all such weapons derive a significant portion, and sometimes a majority, of their energy from fission (including fission induced by neutrons from fusion reactions). Unlike fission weapons, there are no inherent limits on the energy released by thermonuclear weapons. Only six countries—United States, Russia, United Kingdom, People's Republic of China, France and India—have conducted thermonuclear weapon tests. (Whether India has detonated a "true," multi-staged thermonuclear weapon is controversial.)[4]

The basics of the Teller–Ulam design for a hydrogen bomb: a fission bomb uses radiation to compress and heat a separate section of fusion fuel.

Thermonuclear bombs work by using the energy of a fission bomb to compress and heat fusion fuel. In the Teller-Ulam design, which accounts for all multi-megaton yield hydrogen bombs, this is accomplished by placing a fission bomb and fusion fuel (tritium Tritium is a radioactive isotope of hydrogen. The nucleus of tritium (sometimes called a triton) contains one proton and two neutrons, whereas the nucleus of protium (the most abundant hydrogen isotope) contains one proton and no neutrons. Naturally occurring tritium is extremely rare on Earth. The isotope name is formed from the Greek ", deuterium Deuterium, also called heavy hydrogen, is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6,500 of hydrogen . Deuterium thus accounts for approximately 0.0154% (alternately, on a mass basis: 0.0308%) of all naturally occurring hydrogen in the oceans on Earth (see VSMOW; the abundance, or lithium deuteride) in proximity within a special, radiation-reflecting container. When the fission bomb is detonated, gamma and X-rays emitted first compress the fusion fuel, then heat it to thermonuclear temperatures. The ensuing fusion reaction creates enormous numbers of high-speed neutrons, which can then induce fission in materials not normally prone to it, such as depleted uranium. Each of these components is known as a "stage," with the fission bomb as the "primary" and the fusion capsule as the "secondary." In large hydrogen bombs, about half of the yield, and much of the resulting nuclear fallout, comes from the final fissioning of depleted uranium.[3]

By chaining together numerous stages with increasing amounts of fusion fuel, thermonuclear weapons can be made to an almost arbitrary yield; the largest ever detonated (the Tsar Bomba of the USSR) released an energy equivalent of over 50 million tons (50 megatons) of TNT. Most thermonuclear weapons are considerably smaller than this, due to practical constraints arising from the space and weight requirements of missile warheads.[5]

There are other types of nuclear weapons as well. For example, a boosted fission weapon is a fission bomb which increases its explosive yield through a small amount of fusion reactions, but it is not a fusion bomb. In the boosted bomb, the neutrons produced by the fusion reactions serve primarily to increase the efficiency of the fission bomb. Some weapons are designed for special purposes; a neutron bomb is a thermonuclear weapon that yields a relatively small explosion but a relatively large amount of neutron radiation; such a device could theoretically be used to cause massive casualties while leaving infrastructure mostly intact and creating a minimal amount of fallout.

The detonation of any nuclear weapon is accompanied by a blast of neutron radiation. Surrounding a nuclear weapon with suitable materials (such as cobalt or gold) creates a weapon known as a salted bomb. This device can produce exceptionally large quantities of radioactive contamination.

Most variation in nuclear weapon design is for the purpose of achieving different yields for different situations, and in manipulating design elements to attempt to minimize weapon size.[3]

Weapons delivery

The first nuclear weapons were gravity bombs, such as this "Fat Man" weapon dropped on Nagasaki, Japan. They were very large and could only be delivered by heavy bomber aircraft Main article: Nuclear weapons delivery

Nuclear weapons delivery—the technology and systems used to bring a nuclear weapon to its target—is an important aspect of nuclear weapons relating both to nuclear weapon design and nuclear strategy. Additionally, development and maintenance of delivery options is among the most resource-intensive aspects of a nuclear weapons program: according to one estimate, deployment costs accounted for 57% of the total financial resources spent by the United States in relation to nuclear weapons since 1940.[6]

Historically the first method of delivery, and the method used in the two nuclear weapons actually used in warfare, was as a gravity bomb, dropped from bomber aircraft. This method is usually the first developed by countries as it does not place many restrictions on the size of the weapon and weapon miniaturization is something which requires considerable weapons design knowledge. It does, however, limit the range of attack, the response time to an impending attack, and the number of weapons which can be fielded at any given time.

With the advent of miniaturization, nuclear bombs can be delivered by both strategic bombers and tactical fighter-bombers, allowing an air force to use its current fleet with little or no modification. This method may still be considered the primary means of nuclear weapons delivery; the majority of U.S. nuclear warheads, for example, are free-fall gravity bombs, namely the B61.[3]

A Trident II SLBM launched from a Royal Navy Vanguard class ballistic missile submarine.

More preferable from a strategic point of view is a nuclear weapon mounted onto a missile, which can use a ballistic trajectory to deliver the warhead over the horizon. While even short range missiles allow for a faster and less vulnerable attack, the development of long-range intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) has given some nations the ability to plausibly deliver missiles anywhere on the globe with a high likelihood of success.

More advanced systems, such as multiple independently targetable reentry vehicles (MIRVs) allow multiple warheads to be launched at different targets from one missile, reducing the chance of a successful missile defense. Today, missiles are most common among systems designed for delivery of nuclear weapons. Making a warhead small enough to fit onto a missile, though, can be a difficult task.[3]

Tactical weapons (see above) have involved the most variety of delivery types, including not only gravity bombs and missiles but also artillery shells, land mines, and nuclear depth charges and torpedoes for anti-submarine warfare. An atomic mortar was also tested at one time by the United States. Small, two-man portable tactical weapons (somewhat misleadingly referred to as suitcase bombs), such as the Special Atomic Demolition Munition, have been developed, although the difficulty of combining sufficient yield with portability limits their military utility.[3]

Nuclear strategy

The United States' Peacekeeper missile was a MIRVed delivery system. Each missile could contain up to ten nuclear warheads (shown in red), each of which could be aimed at a different target. These were developed to make missile defense very difficult for an enemy country. Main article: Nuclear warfare

Nuclear warfare strategy is a set of policies that deal with preventing or fighting a nuclear war. The policy of trying to prevent an attack by a nuclear weapon from another country by threatening nuclear retaliation is known as the strategy of nuclear deterrence. The goal in deterrence is to always maintain a second strike capability (the ability of a country to respond to a nuclear attack with one of its own) and potentially to strive for first strike status (the ability to completely destroy an enemy's nuclear forces before they could retaliate). During the Cold War, policy and military theorists in nuclear-enabled countries worked out models of what sorts of policies could prevent one from ever being attacked by a nuclear weapon.

Different forms of nuclear weapons delivery (see above) allow for different types of nuclear strategies. The goals of any strategy are generally to make it difficult for an enemy to launch a pre-emptive strike against the weapon system and difficult to defend against the delivery of the weapon during a potential conflict. Sometimes this has meant keeping the weapon locations hidden, such as deploying them on submarines or rail cars whose locations are very hard for an enemy to track and other times this means protecting them by burying them in hardened bunkers.

Other components of nuclear strategies have included using missile defense (to destroy the missiles before they land) or implementation of civil defense measures (using early-warning systems to evacuate citizens to safe areas before an attack).

Note that weapons which are designed to threaten large populations or to generally deter attacks are known as strategic weapons. Weapons which are designed to actually be used on a battlefield in military situations are known as tactical weapons.

There are critics of the very idea of nuclear strategy for waging nuclear war who have suggested that a nuclear war between two nuclear powers would result in mutual annihilation. From this point of view, the significance of nuclear weapons is purely to deter war because any nuclear war would immediately escalate. out of mutual distrust and fear, resulting in mutually assured destruction. This threat of national, if not global, destruction has been a strong motivation for anti-nuclear weapons activism.

Critics from the peace movement and within the military establishment have questioned the usefulness of such weapons in the current military climate. The use of (or threat of use of) such weapons would generally be contrary to the rules of international law applicable in armed conflict, according to an advisory opinion issued by the International Court of Justice in 1996.

Perhaps the most controversial idea in nuclear strategy is that nuclear proliferation would be desirable. This view argues that, unlike conventional weapons, nuclear weapons successfully deter all-out war between states, and they are said to have done this during the Cold War between the U.S. and the Soviet Union. Political scientist Kenneth Waltz is the most prominent advocate of this argument.

The threat of potentially suicidal terrorists possessing nuclear weapons (a form of nuclear terrorism) complicates the decision process. Mutually assured destruction may not be effective against an enemy who expects to die in a confrontation and would not therefore be deterred by a sense of self-preservation. Further, if the initial act is from a rogue group instead of a sovereign nation, there is no fixed nation or fixed military targets to retaliate against. It has been argued, especially after the September 11, 2001 attacks, that this complication is the sign of the next age of nuclear strategy, distinct from the relative stability of the Cold War.[7]

Governance, control, and law

The International Atomic Energy Agency was created in 1957 in order to encourage the peaceful development of nuclear technology while providing international safeguards against nuclear proliferation

Because of the immense military power they can confer, the political control of nuclear weapons has been a key issue for as long as they have existed; in most countries the use of nuclear force can only be authorized by the head of government or head of state.[8]

In the late 1940s, lack of mutual trust was preventing the United States and the Soviet Union from making ground towards international arms control agreements, but by the 1960s steps were being taken to limit both the proliferation of nuclear weapons to other countries and the environmental effects of nuclear testing. The Partial Test Ban Treaty (1963) restricted all nuclear testing to underground nuclear testing, to prevent contamination from nuclear fallout, while the Nuclear Non-Proliferation Treaty (1968) attempted to place restrictions on the types of activities which signatories could participate in, with the goal of allowing the transference of non-military nuclear technology to member countries without fear of proliferation.

In 1957, the International Atomic Energy Agency (IAEA) was established under the mandate of the United Nations in order to encourage the development of the peaceful applications of nuclear technology, provide international safeguards against its misuse, and facilitate the application of safety measures in its use. In 1996, many nations signed and ratified the Comprehensive Test Ban Treaty which prohibits all testing of nuclear weapons, which would impose a significant hindrance to their development by any complying country.[9]

Additional treaties have governed nuclear weapons stockpiles between individual countries, such as the SALT I and START I treaties, which limited the numbers and types of nuclear weapons between the United States and the Soviet Union.

Nuclear weapons have also been opposed by agreements between countries. Many nations have been declared Nuclear-Weapon-Free Zones, areas where nuclear weapons production and deployment are prohibited, through the use of treaties. The Treaty of Tlatelolco (1967) prohibited any production or deployment of nuclear weapons in Latin America and the Caribbean, and the Treaty of Pelindaba (1964) prohibits nuclear weapons in many African countries. As recently as 2006 a Central Asian Nuclear Weapon Free Zone was established amongst the former Soviet republics of Central Asia prohibiting nuclear weapons.

In the middle of 1996, the International Court of Justice, the highest court of the United Nations, issued an Advisory Opinion concerned with the "Legality of the Threat or Use of Nuclear Weapons". The court ruled that the use or threat of use of nuclear weapons would violate various articles of international law, including the Geneva Conventions, the Hague Conventions, the UN Charter, and the Universal Declaration of Human Rights. In view of the unique, destructive characteristics of nuclear weapons, the International Committee of the Red Cross calls on States to ensure that these weapons are never used, irrespective of whether they consider them to be lawful or not. [10]

Additionally, there have been other, specific actions meant to discourage countries from developing nuclear arms. In the wake of the tests by India and Pakistan in 1998, economic sanctions were (temporarily) levied against both countries, though neither were signatories with the Nuclear Non-Proliferation Treaty. One of the stated casus belli for the initiation of the 2003 Iraq War was an accusation by the United States that Iraq was actively pursuing nuclear arms (though this was soon discovered not to be the case as the program had been discontinued). In 1981, Israel had bombed a nuclear reactor being constructed in Osirak, Iraq, in what it called an attempt to halt Iraq's previous nuclear arms ambitions.

Disarmament

Main article: Nuclear disarmament

Beginning with the 1963 Partial Test Ban Treaty and continuing through the 1996 Comprehensive Test Ban Treaty, there have been many treaties to limit or reduce nuclear weapons testing and stockpiles. The 1968 Nuclear Non-Proliferation Treaty has as one of its explicit conditions that all signatories must "pursue negotiations in good faith" towards the long-term goal of "complete disarmament". However, no nuclear state has treated that aspect of the agreement as having binding force.[11]

Only one country—South Africa—has ever fully renounced nuclear weapons they had independently developed. A number of former Soviet republics—Belarus, Kazakhstan, and Ukraine—returned Soviet nuclear arms stationed in their countries to Russia after the collapse of the USSR.

Uses

The Sedan test from 1962 formed a crater 100 m (330 ft) deep with a diameter of about 390 m (1,300 ft), as a means of investigating the possibilities of using peaceful nuclear explosions for large-scale earth moving.

Apart from their use as weapons, nuclear explosives have been tested and used for various non-military uses, and proposed, but not used for large-scale earth moving. When long term health and clean-up costs were included, there was no economic advantage over conventional explosives.[12]

Synthetic elements, such as einsteinium and fermium, created by neutron bombardment of uranium and plutonium during thermonuclear explosions, were discovered in the aftermath of the first thermonuclear bomb test. In 2008 the worldwide presence of new isotopes from atmospheric testing beginning in the 1950s was developed into a reliable way of detecting art forgeries, as all paintings created after that period may contain traces of cesium-137 and strontium-90, isotopes that did not exist in nature before 1945.[13]

Nuclear explosives have also been seriously studied as potential propulsion mechanisms for space travel (see Project Orion).

Controversy

Main article: Nuclear weapons debate

See also

Aftermath

History

Weapons of mass destruction
By type
Biological Chemical Nuclear Radiological
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References

Notes

  1. ^ Specifically the US B83 nuclear bomb, with a yield of up to 1.2 Megatons.
  2. ^ "Federation of American Scientists: Status of World Nuclear Forces". Fas.org. http://www.fas.org/programs/ssp/nukes/nuclearweapons/nukestatus.html. Retrieved 2010-01-12.
  3. ^ a b c d e f The best overall printed sources on nuclear weapons design are: Hansen, Chuck. U.S. Nuclear Weapons: The Secret History. San Antonio, TX: Aerofax, 1988; and the more-updated Hansen, Chuck. Swords of Armageddon: U.S. Nuclear Weapons Development since 1945. Sunnyvale, CA: Chukelea Publications, 1995.
  4. ^ On India's alleged hydrogen bomb test, see Carey Sublette, What Are the Real Yields of India's Test?.
  5. ^ Sublette, Carey. "The Nuclear Weapon Archive". http://nuclearweaponarchive.org/. Retrieved 2007-03-07.
  6. ^ Stephen I. Schwartz, ed., Atomic Audit: The Costs and Consequences of U.S. Nuclear Weapons Since 1940. Washington, D.C.: Brookings Institution Press, 1998. See also Estimated Minimum Incurred Costs of U.S. Nuclear Weapons Programs, 1940-1996, an excerpt from the book.
  7. ^ See, for example: Feldman, Noah. "Islam, Terror and the Second Nuclear Age," New York Times Magazine (29 October 2006).
  8. ^ In the United States, the President and the Secretary of Defense, acting as the National Command Authority, must jointly authorize the use of nuclear weapons.
  9. ^ Richelson, Jeffrey. Spying on the bomb: American nuclear intelligence from Nazi Germany to Iran and North Korea. New York: Norton, 2006.
  10. ^ Nuclear weapons and international humanitarian law International Committee of the Red Cross
  11. ^ Gusterson, Hugh, "Finding Article VI" Bulletin of the Atomic Scientists (8 January 2007).
  12. ^ Q&A with Scott Kirsch: Digging with bombs
  13. ^ Can past nuclear explosions help detect forgeries?

Bibliography

External links

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Pressurized (PWR) · Boiling (BWR) · Supercritical (SCWR) · Heavy (PHWR · CANDU · SGHWR)
Carbon

Pebble bed (PBMR) · Very high temperature (VHTR) · UHTREX · RBMK · Magnox · AGR
FLiBe

Molten salt (MSR)
None (Fast)

Breeder (FBR) · Liquid-metal-cooled (LMFR) · Integral (IFR) · Traveling Wave (TWR) · SSTAR Generation IV by coolant: (Gas (GFR) · Lead (LFR) · Sodium (SFR))
Power

By country · Economics · Safety · Fusion · Isotope thermoelectric (RTG) · Propulsion (rocket)
Medicine
Imaging

Gamma camera based: Scintigraphy · Positron emission (PET) · Single photon emission (SPECT) X-ray based: Projectional radiography · Computed tomography
Therapy

Radiation therapy · Tomotherapy · Proton · Brachytherapy · Boron neutron capture (BNCT)
Weapon
Topics

History · Design · War · Race · Explosion (effects) · Test (underground) · Delivery · Proliferation · Yield (TNTe)
Lists

States · Tests · Weapons · Free zones · Treaties · Pop culture
Waste
Products

Fission (LLFP) · Activation · Actinide: (Reprocessed uranium · Reactor-grade plutonium · Minor actinide)
Disposal

Fuel cycle · Spent fuel (pool • cask) · HLW · LLW · Repository · Reprocessing · Transmutation

Categories: American inventions | Nuclear weapons

 

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'Atomic Bomb' News
Ellen Bueno: Baldwin on passive path to failure - Baraboo News Republic
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Ellen Bueno: Baldwin on passive path to failure - Baraboo News Republic
Tue, 06 Jul 2010 02:37:43 GMT+00:00
Baraboo News Republic Central Intelligence Agency Director Leon Panetta says Iran now has enough enriched uranium for two atomic bombs and could manufacture weapons within two ... Jalili: Iran Ready for N. Talks with West from September 1 Fars News Agency China denounces new unilateral US sanctions on Iran Reuters Africa China Criticizes US For Unilateral Sanctions On Iran RTT News Dar Al-Hayat  - Thaindian.com
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'Atomic Bomb' Blogs
Atomic Bomb In The Desert
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Atomic Bomb In The Desert

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Sat, 03 Jul 2010 15:58:06 GM

We all know of the effect of the heat of the . atomic bomb. that exploded on the New Mexican desert in 1945 We have seen pictures of the green glass formed on the sand around the area of the explosion.

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'Atomic Bomb' Answers
Who supported the atomic bomb and who opposed it?
Q. Did anyone oppose or try to prevent the atomic bomb? What did they do to stop it? Who supported or helped carry out the governments orders?
Asked by Bethany B - Fri Feb 26 09:42:07 2010 - - 3 Answers - 0 Comments

A. Back in 1945, a lot of people opposed the atomic bombs because they questioned its morality and necessity. On one side you had the scientists who questioned the morality of using atomic bombs. People here included Albert Einstein, Leo Szilard and the scientists of the Manhatten Project led by Dr. James Franck. Albert Einstein went as far to suggest that Truman's real intention of using the atomic bomb was to end the Pacific war before the Soviet Union could get a piece of Japan. "President Roosevelt would have forbidden the atomic bombing of Hiroshima had he been alive... it was probably carried out by Truman to end the Pacific war before the Soviet Union could participate." Albert Einstein (from The New York Times, 8/19/46) "[In… [cont.]
Answered by FIFA - Fri Feb 26 21:02:15 2010

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