Portal:Nuclear technology

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The Nuclear Technology Portal

Introduction

This symbol of radioactivity is internationally recognized.

• Nuclear technology is technology that involves the nuclear reactions of atomic nuclei. Among the notable nuclear technologies are nuclear reactors, nuclear medicine and nuclear weapons. It is also used, among other things, in smoke detectors and gun sights. (Full article...)
  
• Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from nuclear fission, nuclear decay and nuclear fusion reactions. Presently, the vast majority of electricity from nuclear power is produced by nuclear fission of uranium and plutonium in nuclear power plants. Nuclear decay processes are used in niche applications such as radioisotope thermoelectric generators in some space probes such as Voyager 2. Reactors producing controlled fusion power have been operated since 1958 but have yet to generate net power and are not expected to be commercially available in the near future. (Full article...)
  
• A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission (fission or atomic bomb) or a combination of fission and nuclear fusion reactions (thermonuclear weapon), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. (Full article...)

General images -

The following are images from various nuclear technology-related articles on Wikipedia.

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  The Trinity test of the Manhattan Project was the first detonation of a nuclear weapon, which led J. Robert Oppenheimer to recall verses from the Hindu scripture Bhagavad Gita: "If the radiance of a thousand suns were to burst at once into the sky, that would be like the splendor of the mighty one "... "I am become Death, the destroyer of worlds". (from Nuclear weapon)
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  Activity of spent UOx fuel in comparison to the activity of natural uranium ore over time (from Nuclear power)
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  A demilitarized, commercial launch of the Russian Strategic Rocket Forces R-36 ICBM; also known by the NATO reporting name: SS-18 Satan. Upon its first fielding in the late 1960s, the SS-18 remains the single highest throw weight missile delivery system ever built. (from Nuclear weapon)
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  Growth of worldwide nuclear power generation (from Nuclear power)
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  The multi-mission radioisotope thermoelectric generator (MMRTG), used in several space missions such as the Curiosity Mars rover (from Nuclear power)
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  Reactor decay heat as a fraction of full power after the reactor shutdown, using two different correlations. To remove the decay heat, reactors need cooling after the shutdown of the fission reactions. A loss of the ability to remove decay heat caused the Fukushima accident. (from Nuclear power)
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  Induced fission reaction. A neutron is absorbed by a uranium-235 nucleus, turning it briefly into an excited uranium-236 nucleus, with the excitation energy provided by the kinetic energy of the neutron plus the forces that bind the neutron. The uranium-236, in turn, splits into fast-moving lighter elements (fission products) and releases several free neutrons, one or more "prompt gamma rays" (not shown) and a (proportionally) large amount of kinetic energy. (from Nuclear fission)
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  Demonstration against nuclear testing in Lyon, France, in the 1980s (from Nuclear weapon)
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  Death rates per unit of electricity production for different energy sources (from Nuclear power)
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  Some of the Chicago Pile Team, including Enrico Fermi and Leó Szilárd (from Nuclear reactor)
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  Following the 2011 Fukushima Daiichi nuclear disaster, the world's worst nuclear accident since 1986, 50,000 households were displaced after radiation leaked into the air, soil and sea. Radiation checks led to bans of some shipments of vegetables and fish. (from Nuclear power)
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  Ukrainian workers use equipment provided by the US Defense Threat Reduction Agency to dismantle a Soviet-era missile silo. After the end of the Cold War, Ukraine and the other non-Russian, post-Soviet republics relinquished Soviet nuclear stockpiles to Russia. (from Nuclear weapon)
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  A visual representation of an induced nuclear fission event where a slow-moving neutron is absorbed by the nucleus of a uranium-235 atom, which fissions into two fast-moving lighter elements (fission products) and additional neutrons. Most of the energy released is in the form of the kinetic velocities of the fission products and the neutrons. (from Nuclear fission)
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  Drawing of the first artificial reactor, Chicago Pile-1 (from Nuclear fission)
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  Scaled-down model of TOPAZ nuclear reactor (from Nuclear reactor)
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  The Chicago Pile, the first artificial nuclear reactor, built in secrecy at the University of Chicago in 1942 during World War II as part of the US's Manhattan Project (from Nuclear reactor)
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  The nuclear fission display at the Deutsches Museum in Munich. The table and instruments are originals, but would not have been together in the same room. (from Nuclear fission)
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  Olkiluoto 3 under construction in 2009. It was the first EPR, a modernized PWR design, to start construction. (from Nuclear power)
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  Schematic of the ITER tokamak under construction in France (from Nuclear power)
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  The Superphénix, closed in 1998, was one of the few FBRs. (from Nuclear reactor)
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  Edward Teller, often referred to as the "father of the hydrogen bomb" (from Nuclear weapon)
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  Share of electricity production from nuclear, 2024 (from Nuclear power)
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  The first nuclear weapons were gravity bombs, such as this "Fat Man" weapon dropped on Nagasaki, Japan. They were large and could only be delivered by heavy bomber aircraft (from Nuclear weapon)
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  A schematic nuclear fission chain reaction. 1. A uranium-235 atom absorbs a neutron and fissions into two new atoms (fission fragments), releasing three new neutrons and some binding energy. 2. One of those neutrons is absorbed by an atom of uranium-238 and does not continue the reaction. Another neutron is simply lost and does not collide with anything, also not continuing the reaction. However, the one neutron does collide with an atom of uranium-235, which then fissions and releases two neutrons and some binding energy. 3. Both of those neutrons collide with uranium-235 atoms, each of which fissions and releases between one and three neutrons, which can then continue the reaction. (from Nuclear fission)
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  The CANDU Qinshan Nuclear Power Plant (from Nuclear reactor)
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  Nuclear waste flasks generated by the United States during the Cold War are stored underground at the Waste Isolation Pilot Plant (WIPP) in New Mexico. The facility is seen as a potential demonstration for storing spent fuel from civilian reactors. (from Nuclear power)
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  The Ikata Nuclear Power Plant, a pressurized water reactor that cools by using a secondary coolant heat exchanger with a large body of water, an alternative cooling approach to large cooling towers (from Nuclear power)
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  Anti-nuclear protest near nuclear waste disposal centre at Gorleben in northern Germany (from Nuclear power)
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  Protest in Bonn against the nuclear arms race between the US/NATO and the Warsaw Pact, 1981 (from Nuclear weapon)
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  The cooling towers of the Philippsburg Nuclear Power Plant in Germany (from Nuclear fission)
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  Treatment of the interior part of a VVER-1000 reactor frame at Atommash (from Nuclear reactor)
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  NC State's PULSTAR Reactor is a 1 MW pool-type research reactor with 4% enriched, pin-type fuel consisting of UO₂ pellets in zircaloy cladding. (from Nuclear reactor)
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  Soviet OTR-21 Tochka missile. Capable of firing a 100-kiloton nuclear warhead a distance of 185 km (from Nuclear weapon)
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  The stages of binary fission in a liquid drop model. Energy input deforms the nucleus into a fat "cigar" shape, then a "peanut" shape, followed by binary fission as the two lobes exceed the short-range nuclear force attraction distance, and are then pushed apart and away by their electrical charge. In the liquid drop model, the two fission fragments are predicted to be the same size. The nuclear shell model allows for them to differ in size, as usually experimentally observed. (from Nuclear fission)
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  Typical composition of uranium dioxide fuel before and after approximately three years in the once-through nuclear fuel cycle of a LWR (from Nuclear power)
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  Animation of a Coulomb explosion in the case of a cluster of positively charged nuclei, akin to a cluster of fission fragments. Hue level of color is proportional to (larger) nuclei charge. Electrons (smaller) on this time-scale are seen only stroboscopically and the hue level is their kinetic energy. (from Nuclear fission)
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  A Minuteman III ICBM test launch from Vandenberg Air Force Base, United States. MIRVed land-based ICBMs are considered destabilizing because they tend to put a premium on striking first. (from Nuclear weapon)
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  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. (from Nuclear weapon)
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  Ballistic missile submarines have been of great strategic importance for the United States, Russia, and other nuclear powers since they entered service in the Cold War, as they can hide from reconnaissance satellites and fire their nuclear weapons with virtual impunity. (from Nuclear weapon)
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  The Ignalina Nuclear Power Plant – a RBMK type (closed 2009) (from Nuclear reactor)
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  The nuclear fuel cycle begins when uranium is mined, enriched, and manufactured into nuclear fuel (1), which is delivered to a nuclear power plant. After use, the spent fuel is delivered to a reprocessing plant (2) or to a final repository (3). In nuclear reprocessing, 95% of spent fuel can potentially be recycled to be returned to use in a power plant (4). (from Nuclear power)
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  Primary coolant system showing reactor pressure vessel (red), steam generators (purple), pressurizer (blue), and pumps (green) in the three coolant loop Hualong One pressurized water reactor design (from Nuclear reactor)
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  A comparison of prices over time for energy from nuclear fission and from other sources. Over the presented time, thousands of wind turbines and similar were built on assembly lines in mass production resulting in an economy of scale. While nuclear remains bespoke, many first of their kind facilities added in the timeframe indicated and none are in serial production.Our World in Data notes that this cost is the global average, while the 2 projects that drove nuclear pricing upwards were in the US. The organization recognises that the median cost of the most exported and produced nuclear energy facility in the 2010s the South Korean APR1400, remained "constant", including in export.
  LCOE is a measure of the average net present cost of electricity generation for a generating plant over its lifetime. As a metric, it remains controversial as the lifespan of units are not independent but manufacturer projections, not a demonstrated longevity. (from Nuclear power)
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  The mushroom cloud of the atomic bomb dropped on Nagasaki, Japan, on 9 August 1945 rose over 12 kilometres (7.5 mi) above the bomb's hypocenter. An estimated 39,000 people were killed by the atomic bomb, of whom 23,145–28,113 were Japanese factory workers, 2,000 were Korean slave laborers, and 150 were Japanese combatants. (from Nuclear fission)
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  The number of nuclear warheads by country in 2024, based on an estimation by the Federation of American Scientists. (from Nuclear weapon)
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  In thermal nuclear reactors (LWRs in specific), the coolant acts as a moderator that must slow the neutrons before they can be efficiently absorbed by the fuel. (from Nuclear reactor)
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  Proportions of the isotopes uranium-238 (blue) and uranium-235 (red) found in natural uranium and in enriched uranium for different applications. Light water reactors use 3–5% enriched uranium, while CANDU reactors work with natural uranium. (from Nuclear power)
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  Diablo Canyon – a PWR (from Nuclear reactor)
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  The now decommissioned United States' Peacekeeper missile was an ICBM developed to replace the Minuteman missile in the late 1980s. Each missile, like the heavier lift Russian SS-18 Satan, could contain up to ten nuclear warheads (shown in red), each of which could be aimed at a different target. A factor in the development of MIRVs was to make complete missile defense difficult for an enemy country. (from Nuclear weapon)
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  Anti-nuclear weapons protest march in Oxford, 1980 (from Nuclear weapon)
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  Life-cycle greenhouse gas emissions of electricity supply technologies, median values calculated by IPCC (from Nuclear power)
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  UN vote on adoption of the Treaty on the Prohibition of Nuclear Weapons on July 7, 2017
  

    Yes

    No

    Did not vote

  (from Nuclear weapon)
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  The Magnox Sizewell A nuclear power station (from Nuclear reactor)
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  The two basic fission weapon designs (from Nuclear weapon)
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  A photograph of Sumiteru Taniguchi's back injuries taken in January 1946 by a US Marine photographer (from Nuclear weapon)
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  Nuclear fuel assemblies being inspected before entering a pressurized water reactor in the United States (from Nuclear power)
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  The USSR and United States nuclear weapon stockpiles throughout the Cold War until 2015, with a precipitous drop in total numbers following the end of the Cold War in 1991. (from Nuclear weapon)
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  Mushroom cloud from the explosion of Castle Bravo, the largest nuclear weapon detonated by the US, in 1954 (from Nuclear weapon)
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  Lise Meitner and Otto Hahn in their laboratory (from Nuclear reactor)
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  Dry cask storage vessels storing spent nuclear fuel assemblies (from Nuclear power)
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  An example of an induced nuclear fission event. A neutron is absorbed by the nucleus of a uranium-235 atom, which in turn splits into fast-moving lighter elements (fission products) and free neutrons. Though both reactors and nuclear weapons rely on nuclear chain reactions, the rate of reactions in a reactor is much slower than in a bomb. (from Nuclear reactor)
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  The Torness nuclear power station – an AGR (from Nuclear reactor)
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  The Leibstadt Nuclear Power Plant in Switzerland (from Nuclear power)
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  The status of nuclear power globally (click for legend) (from Nuclear power)
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  The first light bulbs ever lit by electricity generated by nuclear power at EBR-1 at Argonne National Laboratory-West, December 20, 1951. (from Nuclear power)
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  Three of the reactors at Fukushima I overheated, causing the coolant water to dissociate and led to the hydrogen explosions. This along with fuel meltdowns released large amounts of radioactive material into the air. (from Nuclear reactor)
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  Over 2,000 nuclear explosions have been conducted in over a dozen different sites around the world. Red Russia/Soviet Union, blue France, light blue United States, violet Britain, yellow China, orange India, brown Pakistan, green North Korea and light green (territories exposed to nuclear bombs). The black dot indicates the location of the Vela incident. (from Nuclear weapon)
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  The launching ceremony of USS Nautilus January 1954. In 1958 it would become the first vessel to reach the North Pole. (from Nuclear power)
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  Most waste packaging, small-scale experimental fuel recycling chemistry and radiopharmaceutical refinement is conducted within remote-handled hot cells. (from Nuclear power)
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  The "curve of binding energy": A graph of binding energy per nucleon of common isotopes. (from Nuclear fission)
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  Otto Hahn and Lise Meitner in 1912 (from Nuclear fission)
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  Montage of an inert test of a United States Trident SLBM (submarine launched ballistic missile), from submerged to the terminal, or re-entry phase, of the multiple independently targetable reentry vehicles (from Nuclear weapon)
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  The Calder Hall nuclear power station in the United Kingdom, the world's first commercial nuclear power station (from Nuclear power)
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  This view of downtown Las Vegas shows a mushroom cloud in the background. Scenes such as this were typical during the 1950s. From 1951 to 1962 the government conducted 100 atmospheric tests at the nearby Nevada Test Site. (from Nuclear weapon)
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  Fission product yields by mass for thermal neutron fission of uranium-235, plutonium-239, a combination of the two typical of current nuclear power reactors, and uranium-233, used in the thorium cycle (from Nuclear fission)
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  The town of Pripyat abandoned since 1986, with the Chernobyl plant and the Chernobyl New Safe Confinement arch in the distance (from Nuclear power)

Selected article -

Uranium is a chemical element; it has symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactively decays, usually by emitting an alpha particle. The half-life of this decay varies between 159,200 and 4.5 billion years for different isotopes, making them useful for dating the age of the Earth. The most common isotopes in natural uranium are uranium-238 (which has 146 neutrons and accounts for over 99% of uranium on Earth) and uranium-235 (which has 143 neutrons). Uranium has the highest atomic weight of the primordially occurring elements. Its density is about 70% higher than that of lead and slightly lower than that of gold or tungsten. It occurs naturally in low concentrations of a few parts per million in soil, rock and water, and is commercially extracted from uranium-bearing minerals such as uraninite.

Many contemporary uses of uranium exploit its unique nuclear properties. Uranium is used in nuclear power plants and nuclear weapons because it is the only naturally occurring element with a fissile isotope – uranium-235 – present in non-trace amounts. However, because of the low abundance of uranium-235 in natural uranium (which is overwhelmingly uranium-238), uranium needs to undergo enrichment so that enough uranium-235 is present. Uranium-238 is fissionable by fast neutrons and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is studied for future industrial use in nuclear technology. Uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons; uranium-235, and to a lesser degree uranium-233, have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction. This generates the heat in nuclear power reactors and produces the fissile material for nuclear weapons. The primary civilian use for uranium harnesses the heat energy to produce electricity. Depleted uranium (²³⁸U) is used in kinetic energy penetrators and armor plating.

The 1789 discovery of uranium in the mineral pitchblende is credited to Martin Heinrich Klaproth, who named the new element after the recently discovered planet Uranus. Eugène-Melchior Péligot was the first person to isolate the metal, and its radioactive properties were discovered in 1896 by Henri Becquerel. Research by Otto Hahn, Lise Meitner, Enrico Fermi and others, such as J. Robert Oppenheimer starting in 1934 led to its use as a fuel in the nuclear power industry and in Little Boy, the first nuclear weapon used in war. An ensuing arms race during the Cold War between the United States and the Soviet Union produced tens of thousands of nuclear weapons that used uranium metal and uranium-derived plutonium-239. Dismantling of these weapons and related nuclear facilities is carried out within various nuclear disarmament programs and costs billions of dollars. Weapon-grade uranium obtained from nuclear weapons is diluted with uranium-238 and reused as fuel for nuclear reactors. Spent nuclear fuel forms radioactive waste, which mostly consists of uranium-238 and poses a significant health threat and environmental impact. (Full article...)

More selected articles

Selected picture -

Credit: Unknown (see OTRS also)

Interior of an Ames Process pressure vessel with slag coating the outside and bottom (after reaction and removal of uranium metal). ~1943
Attribution: The Ames Laboratory, USDOE (http://www.ameslab.gov/)

Did you know?

• ... that Fritz Strassmann, a co-discoverer of nuclear fission, concealed a Jewish woman in his home during World War II?
• ... that a nuclear reactor was nearly built at the New York Hall of Science, but the money for the institution instead went to Yankee Stadium?
• ... that the 1991 Andover tornado narrowly avoided hitting two warplanes equipped with nuclear warheads?
• ... that the British National Hospital Service Reserve trained volunteers to carry out first aid in the aftermath of a nuclear or chemical attack?
• ... that poet Peggy Pond Church became a strong pacifist and a member of the Society of Friends after the Manhattan Project used her home as a place to build nuclear weapons?
• ... that the Russian and Belarussian military exercise Zapad 2009 involved nuclear-capable ballistic missiles?

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Selected biography -

Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor of Spanish descent who was awarded the Nobel Prize in Physics in 1968 for his discovery of resonance states in particle physics using the hydrogen bubble chamber. In 2007 the American Journal of Physics commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century."

After receiving his PhD from the University of Chicago in 1936, Alvarez went to work for Ernest Lawrence at the Radiation Laboratory at the University of California, Berkeley. Alvarez devised a set of experiments to observe K-electron capture in radioactive nuclei, predicted by the beta decay theory but never before observed. He produced tritium using the cyclotron and measured its lifetime. In collaboration with Felix Bloch, he measured the magnetic moment of the neutron.

In 1940, Alvarez joined the MIT Radiation Laboratory, where he contributed to a number of World War II radar projects, from early improvements to Identification friend or foe (IFF) radar beacons, now called transponders, to a system known as VIXEN for preventing enemy submarines from realizing that they had been found by the new airborne microwave radars. The radar system for which Alvarez is best known and which has played a major role in aviation, most particularly in the post war Berlin airlift, was Ground Controlled Approach (GCA). Alvarez spent a few months at the University of Chicago working on nuclear reactors for Enrico Fermi before coming to Los Alamos to work for Robert Oppenheimer on the Manhattan Project. Alvarez worked on the design of explosive lenses, and the development of exploding-bridgewire detonators. As a member of Project Alberta, he observed the Trinity nuclear test from a B-29 Superfortress, and later the bombing of Hiroshima from the B-29 The Great Artiste.

After the war Alvarez was involved in the design of a liquid hydrogen bubble chamber that allowed his team to take millions of photographs of particle interactions, develop complex computer systems to measure and analyze these interactions, and discover entire families of new particles and resonance states. This work resulted in his being awarded the Nobel Prize in 1968. He was involved in a project to x-ray the Egyptian pyramids to search for unknown chambers. With his son, geologist Walter Alvarez, he developed the Alvarez hypothesis which proposes that the extinction event that wiped out the non-avian dinosaurs was the result of an asteroid impact. (Full article...)

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Nuclear technology news

1 August 2025 – Russian invasion of Ukraine

U.S. president Donald Trump orders the deployment of two United States Navy nuclear submarines near Russia for potential military action against Russian forces in response to statements made by former Russian president Dmitry Medvedev and current deputy chairman of the Security Council of the Russian Federation regarding Trump's previously-stated deadline for ending the war in Ukraine. (Reuters) (BBC News)

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