Nuclear explosion

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A 23 kiloton tower shot called BADGER, fired on April 18, 1953, at the Nevada Test Site, as part of the Operation Upshot-Knothole nuclear test series. Operation Upshot-Knothole - Badger 001.jpg
A 23 kiloton tower shot called BADGER, fired on April 18, 1953, at the Nevada Test Site, as part of the Operation Upshot–Knothole nuclear test series.
The Greenhouse George test early fireball.
Upshot–Knothole Grable test (film)

A nuclear explosion is an explosion that occurs as a result of the rapid release of energy from a high-speed nuclear reaction. The driving reaction may be nuclear fission or nuclear fusion or a multi-stage cascading combination of the two, though to date all fusion-based weapons have used a fission device to initiate fusion, and a pure fusion weapon remains a hypothetical device. Nuclear explosions are used in nuclear weapons and nuclear testing.

Contents

Nuclear explosions are extremely destructive compared to conventional (chemical) explosives, because of the vastly greater energy density of nuclear fuel compared to chemical explosives. They are often associated with mushroom clouds, since any large atmospheric explosion can create such a cloud. Nuclear explosions produce high levels of ionizing radiation and radioactive debris that is harmful to humans and can cause moderate to severe skin burns, eye damage, radiation sickness, radiation-induced cancer and possible death depending on how far a person is from the blast radius. [1] Nuclear explosions can also have detrimental effects on the climate, lasting from months to years. A small-scale nuclear war could release enough particles into the atmosphere to cause the planet to cool and cause crops, animals, and agriculture to disappear across the globe—an effect named nuclear winter. [2]

History

The beginning (fission explosions)

The first manmade nuclear explosion occurred on July 16, 1945, at 5:50 am on the Trinity test site near Alamogordo, New Mexico, in the United States, an area now known as the White Sands Missile Range. [3] [4] The event involved the full-scale testing of an implosion-type fission atomic bomb. In a memorandum to the U.S. Secretary of War, General Leslie Groves describes the yield as equivalent to 15,000 to 20,000 tons of TNT. [5] Following this test, a uranium-gun type nuclear bomb (Little Boy) was dropped on the Japanese city of Hiroshima on August 6, 1945, with a blast yield of 15 kilotons; and a plutonium implosion-type bomb (Fat Man) on Nagasaki on August 9, 1945, with a blast yield of 21 kilotons. Fat Man and Little Boy are the only instances in history of nuclear weapons being used as an act of war.

On August 29, 1949, the USSR became the second country to successfully test a nuclear weapon. RDS-1, dubbed "First Lightning" by the Soviets and "Joe-1" by the US, produced a 20 kiloton explosion and was essentially a copy of the American Fat Man plutonium implosion design. [6]

Thermonuclear Era (fusion explosions)

The United States' first thermonuclear weapon, Ivy Mike, was detonated on 1 November 1952 at Enewetak Atoll and yielded 10 Megatons of explosive force. The first thermonuclear weapon tested by the USSR, RDS-6s (Joe-4), was detonated on August 12, 1953, at the Semipalatinsk Test Site in Kazakhstan and yielded about 400 kilotons. [7] RDS-6s' design, nicknamed the Sloika, was remarkably similar to a version designed for the U.S. by Edward Teller nicknamed the "Alarm Clock", in that the nuclear device was a two-stage weapon: the first explosion was triggered by fission and the second more powerful explosion by fusion. The Sloika core consisted of a series of concentric spheres with alternating materials to help boost the explosive yield.

Proliferation Era

In the years following World War II, eight countries have conducted nuclear tests with 2475 devices fired in 2120 tests. [8] In 1963, the United States, Soviet Union, and United Kingdom signed the Limited Test Ban Treaty, pledging to refrain from testing nuclear weapons in the atmosphere, underwater, or in outer space. The treaty permitted underground tests. Many other non-nuclear nations acceded to the Treaty following its entry into force; however, France and China (both nuclear weapons states) have not.[ citation needed ]

The primary application to date has been military (i.e. nuclear weapons), and the remainder of explosions include the following:

Nuclear weapons

Two nuclear weapons have been deployed in combat—both by the United States against Japan in World War II. The first event occurred on the morning of 6 August 1945, when the United States Army Air Forces dropped a uranium gun-type device, code-named "Little Boy", on the city of Hiroshima, killing 70,000 people, including 20,000 Japanese combatants and 20,000 Korean slave laborers. The second event occurred three days later when the United States Army Air Forces dropped a plutonium implosion-type device, code-named "Fat Man", on the city of Nagasaki. It killed 39,000 people, including 27,778 Japanese munitions employees, 2,000 Korean slave laborers, and 150 Japanese combatants. In total, around 109,000 people were killed in these bombings. Nuclear weapons are largely seen as a 'deterrent' by most governments; the sheer scale of the destruction caused by nuclear weapons has discouraged their use in warfare. [ citation needed ]

Nuclear testing

Since the Trinity test and excluding combat use, countries with nuclear weapons have detonated roughly 1,700 nuclear explosions, all but six as tests. Of these, six were peaceful nuclear explosions. Nuclear tests are experiments carried out to determine the effectiveness, yield and explosive capability of nuclear weapons. Throughout the 20th century, most nations that have developed nuclear weapons had a staged test of them. Testing nuclear weapons can yield information about how the weapons work, as well as how the weapons behave under various conditions and how structures behave when subjected to a nuclear explosion. Additionally, nuclear testing has often been used as an indicator of scientific and military strength, and many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status by means of a nuclear test. Nuclear tests have taken place at more than 60 locations across the world; some in secluded areas and others more densely populated. [9] Detonation of nuclear weapons (in a test or during war) releases radioactive fallout that concerned the public in the 1950s. This led to the Limited Test Ban Treaty of 1963 signed by the United States, Great Britain, and the Soviet Union. This treaty banned nuclear weapons testing in the atmosphere, outer space, and under water. [10]

Effects of nuclear explosions

Shockwaves and radiation

The dominant effect of a nuclear weapon (the blast and thermal radiation) are the same physical damage mechanisms as conventional explosives, but the energy produced by a nuclear explosive is millions of times more per gram and the temperatures reached are in the tens of megakelvin. Nuclear weapons are quite different from conventional weapons because of the huge amount of explosive energy that they can put out and the different kinds of effects they make, like high temperatures and ionizing radiation.

The devastating impact of the explosion does not stop after the initial blast, as with conventional explosives. A cloud of nuclear radiation travels from the hypocenter of the explosion, causing an impact to life forms even after the heat waves have ceased. The health effects on humans from nuclear explosions comes from the initial shockwave, the radiation exposure, and the fallout. The initial shockwave and radiation exposure come from the immediate blast which has different effects on the health of humans depending on the distance from the center of the blast. The shockwave can rupture eardrums and lungs, can also throw people back, and cause buildings to collapse. [11] Radiation exposure is delivered at the initial blast and can continue for an extended amount of time in the form of nuclear fallout. The main health effect of nuclear fallout is cancer and birth defects because radiation causes changes in cells that can either kill or make them abnormal. [12] Any nuclear explosion (or nuclear war) would have wide-ranging, long-term, catastrophic effects. Radioactive contamination would cause genetic mutations and cancer across many generations. [13]

Nuclear winter

Another potential devastating effect of nuclear war is termed nuclear winter. The idea became popularized in mainstream culture during the 1980s, when Richard P. Turco, Owen Toon, Thomas P. Ackerman, James B. Pollack and Carl Sagan collaborated and produced a scientific study which suggested the Earth's weather and climate can be severely impacted by nuclear war. [14] The main idea is that once a conflict begins and the aggressors start detonating nuclear weapons, the explosions will eject small particles from the Earth's surface into the atmosphere as well as nuclear particles. It's also assumed that fires will break out and become widespread, similar to what happened at Hiroshima and Nagasaki during the end of WWII, which will cause soot and other harmful particles to also be introduced into the atmosphere. [15] Once these harmful particles are lofted, strong upper-level winds in the troposphere can transport them thousands of kilometers and can end up transporting nuclear fallout and also alter the Earth's radiation budget. Once enough small particles are in the atmosphere, they can act as cloud condensation nuclei which will cause global cloud coverage to increase which in turn blocks incoming solar insolation and starts a global cooling period. This is not unlike one of the leading theories about the extinction of most dinosaur species, in that a large explosion ejected small particulate matter into the atmosphere and resulted in a global catastrophe characterized by cooler temperatures, acid rain, and the KT Layer. [16]

See also

Related Research Articles

<span class="mw-page-title-main">Little Boy</span> Atomic bomb dropped on Hiroshima

Little Boy was a type of atomic bomb created by the United States as part of the Manhattan Project during World War II. The name is also often used to describe the specific bomb (L-11) used in the bombing of the Japanese city of Hiroshima by the Boeing B-29 Superfortress Enola Gay on 6 August 1945, making it the first nuclear weapon used in warfare, and the second nuclear explosion in history, after the Trinity nuclear test. It exploded with an energy of approximately 15 kilotons of TNT (63 TJ) and had an explosion radius of approximately 1.3 kilometres (0.81 mi) which caused widespread death across the city. It was a gun-type fission weapon which used uranium that had been enriched in the isotope uranium-235 to power its explosive reaction.

<span class="mw-page-title-main">Nuclear weapon</span> Explosive weapon that utilizes nuclear reactions

A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion reactions, producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter.

A neutron bomb, officially defined as a type of enhanced radiation weapon (ERW), is a low-yield thermonuclear weapon designed to maximize lethal neutron radiation in the immediate vicinity of the blast while minimizing the physical power of the blast itself. The neutron release generated by a nuclear fusion reaction is intentionally allowed to escape the weapon, rather than being absorbed by its other components. The neutron burst, which is used as the primary destructive action of the warhead, is able to penetrate enemy armor more effectively than a conventional warhead, thus making it more lethal as a tactical weapon.

<span class="mw-page-title-main">Nuclear fallout</span> Residual radioactive material following a nuclear blast

Nuclear fallout is residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioactive dust and ash created when a nuclear weapon explodes. The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated. Fallout may get entrained with the products of a pyrocumulus cloud and when combined with precipitation falls as black rain, which occurred within 30–40 minutes of the atomic bombings of Hiroshima and Nagasaki. This radioactive dust, usually consisting of fission products mixed with bystanding atoms that are neutron-activated by exposure, is a form of radioactive contamination.

<span class="mw-page-title-main">Nuclear weapon design</span> Process by which nuclear WMDs are designed and produced

Nuclear Weapons Design are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types:

  1. Pure fission weapons are the simplest, least technically demanding, were the first nuclear weapons built, and so far the only type ever used in warfare, by the United States on Japan in World War II.
  2. Boosted fission weapons increase yield beyond that of the implosion design, by using small quantities of fusion fuel to enhance the fission chain reaction. Boosting can more than double the weapon's fission energy yield.
  3. Staged thermonuclear weapons are arrangements of two or more "stages", most usually two. The first stage is normally a boosted fission weapon as above. Its detonation causes it to shine intensely with X-rays, which illuminate and implode the second stage filled with a large quantity of fusion fuel. This sets in motion a sequence of events which results in a thermonuclear, or fusion, burn. This process affords potential yields up to hundreds of times those of fission weapons.
<span class="mw-page-title-main">Effects of nuclear explosions</span> Type and severity of damage caused by nuclear weapons

The effects of a nuclear explosion on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional explosives. In most cases, the energy released from a nuclear weapon detonated within the lower atmosphere can be approximately divided into four basic categories:

<span class="mw-page-title-main">Project Plowshare</span> U.S. program examining the peaceful applications of nuclear explosives (1961–77)

Project Plowshare was the overall United States program for the development of techniques to use nuclear explosives for peaceful construction purposes. The program was organized in June 1957 as part of the worldwide Atoms for Peace efforts. As part of the program, 35 nuclear warheads were detonated in 27 separate tests. A similar program was carried out in the Soviet Union under the name Nuclear Explosions for the National Economy, although the Soviet program consisted of 124 tests.

<span class="mw-page-title-main">Mushroom cloud</span> Cloud of debris and smoke from a large explosion

A mushroom cloud is a distinctive mushroom-shaped flammagenitus cloud of debris, smoke, and usually condensed water vapour resulting from a large explosion. The effect is most commonly associated with a nuclear explosion, but any sufficiently energetic detonation or deflagration will produce a similar effect. They can be caused by powerful conventional weapons, including thermobaric weapons such as the ATBIP and GBU-43/B MOAB. Some volcanic eruptions and impact events can produce natural mushroom clouds.

<span class="mw-page-title-main">Radiological warfare</span> Attacks using radioactive material with intent of contamination of an area

Radiological warfare is any form of warfare involving deliberate radiation poisoning or contamination of an area with radiological sources.

<span class="mw-page-title-main">Nuclear weapons testing</span> Controlled detonation of nuclear weapons for scientific or political purposes

Nuclear weapons tests are experiments carried out to determine the performance, yield, and effects of nuclear weapons. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions. Nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.

<span class="mw-page-title-main">Operation Castle</span> Series of 1950s US nuclear tests

Operation Castle was a United States series of high-yield (high-energy) nuclear tests by Joint Task Force 7 (JTF-7) at Bikini Atoll beginning in March 1954. It followed Operation Upshot–Knothole and preceded Operation Teapot.

<span class="mw-page-title-main">Operation Greenhouse</span> Series of 1950s US nuclear tests

Operation Greenhouse was the fifth American nuclear test series, the second conducted in 1951 and the first to test principles that would lead to developing thermonuclear weapons. Conducted at the new Pacific Proving Ground, on islands of the Enewetak Atoll, it mounted the devices on large steel towers to simulate air bursts. This series of nuclear weapons tests was preceded by Operation Ranger and succeeded by Operation Buster-Jangle.

<span class="mw-page-title-main">Castle Bravo</span> 1954 U.S. thermonuclear weapon test in the Marshall Islands

Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of Operation Castle. Detonated on 1 March 1954, the device remains the most powerful nuclear device ever detonated by the United States and the first lithium deuteride-fueled thermonuclear weapon tested using the Teller-Ulam design. Castle Bravo's yield was 15 megatons of TNT [Mt] (63 PJ), 2.5 times the predicted 6 Mt (25 PJ), due to unforeseen additional reactions involving lithium-7, which led to radioactive contamination in the surrounding area.

<span class="mw-page-title-main">Chagan (nuclear test)</span> 1965 Soviet underground nuclear test

Chagan (Чага́н) was a Soviet underground nuclear test conducted at the Semipalatinsk Test Site on January 15, 1965.

<span class="mw-page-title-main">Sedan (nuclear test)</span> 1962 underground nuclear test at the Nevada Test Site

Storax Sedan was a shallow underground nuclear test conducted in Area 10 of Yucca Flat at the Nevada National Security Site on July 6, 1962, as part of Operation Plowshare, a program to investigate the use of nuclear weapons for mining, cratering, and other civilian purposes. The radioactive fallout from the test contaminated more US residents than any other nuclear test. The Sedan Crater is the largest human-made crater in the United States and is listed on the National Register of Historic Places.

<span class="mw-page-title-main">Thermonuclear weapon</span> 2-stage nuclear weapon

A thermonuclear weapon, fusion weapon or hydrogen bomb (H bomb) is a second-generation nuclear weapon design. Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs, a more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material such as uranium-235 or plutonium-239. The first full-scale thermonuclear test was carried out by the United States in 1952, and the concept has since been employed by most of the world's nuclear powers in the design of their weapons.

Peaceful nuclear explosions (PNEs) are nuclear explosions conducted for non-military purposes. Proposed uses include excavation for the building of canals and harbours, electrical generation, the use of nuclear explosions to drive spacecraft, and as a form of wide-area fracking. PNEs were an area of some research from the late 1950s into the 1980s, primarily in the United States and Soviet Union.

<span class="mw-page-title-main">Nuclear weapon yield</span> Energy released in nuclear weapons explosions

The explosive yield of a nuclear weapon is the amount of energy released such as blast, thermal, and nuclear radiation, when that particular nuclear weapon is detonated, usually expressed as a TNT equivalent (the standardized equivalent mass of trinitrotoluene which, if detonated, would produce the same energy discharge), either in kilotonnes (kt—thousands of tonnes of TNT), in megatonnes (Mt—millions of tonnes of TNT), or sometimes in terajoules (TJ). An explosive yield of one terajoule is equal to 0.239 kilotonnes of TNT. Because the accuracy of any measurement of the energy released by TNT has always been problematic, the conventional definition is that one kilotonne of TNT is held simply to be equivalent to 1012 calories.

<span class="mw-page-title-main">Underground nuclear weapons testing</span> Test detonation of nuclear weapons underground

Underground nuclear testing is the test detonation of nuclear weapons that is performed underground. When the device being tested is buried at sufficient depth, the nuclear explosion may be contained, with no release of radioactive materials to the atmosphere.

<span class="mw-page-title-main">Fizzle (nuclear explosion)</span> Nuclear explosion with much less than expected yield

A fizzle occurs when the detonation of a device for creating a nuclear explosion grossly fails to meet its expected yield. The bombs still detonate, but the detonation is much weaker than anticipated. The cause(s) for the failure might be linked to improper design, poor construction, or lack of expertise. All countries that have had a nuclear weapons testing program have experienced some fizzles. A fizzle can spread radioactive material throughout the surrounding area, involve a partial fission reaction of the fissile material, or both. For practical purposes, a fizzle can still have considerable explosive yield when compared to conventional weapons.

References

  1. ↑ "CDC Radiation Emergencies | Frequently Asked Questions About a Nuclear Blast". www.cdc.gov. 2019-04-22. Retrieved 2021-04-29.
  2. ↑ Rubinson, Paul (2014-01-02). "The global effects of nuclear winter: science and antinuclear protest in the United States and the Soviet Union during the 1980s". Cold War History. 14 (1): 47–69. doi:10.1080/14682745.2012.759560. ISSN   1468-2745. S2CID   153883165.
  3. ↑ U.S. Department of Energy. "Trinity Site - World's First Nuclear Explosion". Energy.gov Office of Management. Retrieved 23 December 2016.
  4. ↑ Taylor, Alan (July 16, 2015). "70 Years Since Trinity: The Day the Nuclear Age Began". The Atlantic. Retrieved 23 December 2016.
  5. ↑ Groves, General Leslie (July 18, 1945). "The First Nuclear Test in New Mexico: Memorandum for the Secretary of War, Subject: The Test". United States War Department. PBS.org. Retrieved 23 December 2016.
  6. ↑ "VENONA Dated Documents". www.nsa.gov. Retrieved 2021-04-30.
  7. ↑ "The Soviet Nuclear Weapons Program". nuclearweaponarchive.org. Retrieved 2021-04-30.
  8. ↑ Yang, Xiaoping; North, Robert; Romney, Carl; Richards, Paul G. (August 2000), Worldwide Nuclear Explosions (PDF), retrieved 2013-12-31
  9. ↑ "The legacy of nuclear testing". ICAN. Retrieved 2021-04-29.
  10. ↑ "Our Documents - Test Ban Treaty (1963)". www.ourdocuments.gov. 9 April 2021. Retrieved 2021-04-29.
  11. ↑ Effects of Nuclear Earth-Penetrator and Other Weapons. 2005-09-06. doi:10.17226/11282. ISBN   978-0-309-09673-7.
  12. ↑ "Effects to the Human Body From Nuclear Fallout". large.stanford.edu. Retrieved 2021-04-29.
  13. ↑ Malcolm Fraser and Tilman Ruff. 2015 is the year to ban nuclear weapons, The Age , February 19, 2015.
  14. ↑ Turco, R. P.; Toon, O. B.; Ackerman, T. P.; Pollack, J. B.; Sagan, Carl (1983-12-23). "Nuclear Winter: Global Consequences of Multiple Nuclear Explosions". Science. 222 (4630): 1283–1292. Bibcode:1983Sci...222.1283T. doi:10.1126/science.222.4630.1283. ISSN   0036-8075. PMID   17773320. S2CID   45515251.
  15. ↑ "Radiation Dose Reconstruction: U.S. Occupation Forces In Hiroshima and Nagasaki, Japan, 1945-1946" (PDF). 2006-06-24. Archived from the original (PDF) on 2006-06-24. Retrieved 2021-04-30.
  16. ↑ "The KT extinction". ucmp.berkeley.edu. Retrieved 2021-04-30.
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