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Windscale Fire
The Windscale fire of 10 October 1957 was the worst nuclear accident in the United Kingdom's history, and one of the worst in the world, ranked in severity at level 5 out of a possible 7 on the International Nuclear Event Scale. The fire was in Unit 1 of the two-pile Windscale site on the north-west coast of England in Cumberland (now Sellafield, Cumbria). The two graphite-moderated reactors, referred to at the time as "piles," had been built as part of the British post-war atomic bomb project. Windscale Pile No. 1 was operational in October 1950, followed by Pile No. 2 in June 1951. The fire burned for three days and released radioactive fallout which spread across the UK and the rest of Europe. The radioactive isotope iodine-131, which may lead to cancer of the thyroid, was of particular concern at the time. It has since come to light that small but significant amounts of the highly dangerous radioactive isotope polonium-210 were also released. It is estimated that the radia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seascale
Seascale is a village and civil parish on the Irish Sea coast of Cumbria, England, historically within Cumberland. The parish had a population of 1,747 in 2001, barely increasing by 0.4 % in 2011. History The place-name indicates that it was inhabited by Norse settlers, probably before 1000 AD. It is derived from ''skali'', meaning in Norse a wooden hut or shelter. This could well date from the time of King Harold Fairhair, who vowed revenge on the many Norsemen who had settled in Ireland and the Isle of Man, causing them to flee across the sea to the Cumbrian coast some time after AD 885. Many other Norse place names are to be found, including Seascale How, ''Skala Haugr'', (the hill near the shelter), and Whitriggs, ''hvitihrgger'' (the white ridge). As the Norse penetrated inland other skalar were named, so Seascale was distinguished by reference to the sea. The earliest written reference to Seascale is in the period 1154–1181, when an Aldwin de Seascale was witness to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Hahn
Otto Hahn (; 8 March 1879 – 28 July 1968) was a German chemist who was a pioneer in the fields of radioactivity and radiochemistry. He is referred to as the father of nuclear chemistry and father of nuclear fission. Hahn and Lise Meitner discovered radioactive isotopes of radium, thorium, protactinium and uranium. He also discovered the phenomena of atomic recoil and nuclear isomerism, and pioneered rubidium–strontium dating. In 1938, Hahn, Lise Meitner and Fritz Strassmann discovered nuclear fission, for which Hahn received the 1944 Nobel Prize for Chemistry. Nuclear fission was the basis for nuclear reactors and nuclear weapons. A graduate of the University of Marburg, Hahn studied under Sir William Ramsay at University College London and at McGill University in Montreal under Ernest Rutherford, where he discovered several new radioactive isotopes. He returned to Germany in 1906; Emil Fischer placed a former woodworking shop in the basement of the Chemical Institute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhattan Project
The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the United States Army Corps of Engineers, U.S. Army Corps of Engineers. Nuclear physicist Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs. The Army component of the project was designated the Manhattan District as its first headquarters were in Manhattan; the placename gradually superseded the official codename, Development of Substitute Materials, for the entire project. Along the way, the project absorbed its earlier British counterpart, Tube Alloys. The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion (equivalent to about $ billion in ). Over 90 percent of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quebec Agreement
The Quebec Agreement was a secret agreement between the United Kingdom and the United States outlining the terms for the coordinated development of the science and engineering related to nuclear energy and specifically nuclear weapons. It was signed by Winston Churchill and Franklin D. Roosevelt on 19 August 1943, during World War II, at the First Quebec Conference in Quebec City, Quebec, Canada. The Quebec Agreement stipulated that the US and UK would pool their resources to develop nuclear weapons, and that neither country would use them against the other, or against other countries without mutual consent, or pass information about them to other countries. It also gave the United States a veto over post-war British commercial or industrial uses of nuclear energy. The agreement merged the British Tube Alloys project with the American Manhattan Project, and created the Combined Policy Committee to control the joint project. Although Canada was not a signatory, the Agreement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tube Alloys
Tube Alloys was the research and development programme authorised by the United Kingdom, with participation from Canada, to develop nuclear weapons during the Second World War. Starting before the Manhattan Project in the United States, the British efforts were kept classified, and as such had to be referred to by code even within the highest circles of government. The possibility of nuclear weapons was acknowledged early in the war. At the University of Birmingham, Rudolf Peierls and Otto Robert Frisch co-wrote a memorandum explaining that a small mass of pure uranium-235 could be used to produce a chain reaction in a bomb with the power of thousands of tons of TNT. This led to the formation of the MAUD Committee, which called for an all-out effort to develop nuclear weapons. Wallace Akers, who oversaw the project, chose the deliberately misleading code name "Tube Alloys". His Tube Alloys Directorate was part of the Department of Scientific and Industrial Research. The Tube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium-235
Uranium-235 (235U or U-235) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a nuclear chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide. Uranium-235 has a half-life of 703.8 million years. It was discovered in 1935 by Arthur Jeffrey Dempster. Its fission cross section for slow thermal neutrons is about 584.3±1 barns. For fast neutrons it is on the order of 1 barn. Most but not all neutron absorptions result in fission; a minority result in neutron capture forming uranium-236. Natural decay chain :\begin \ce \begin \ce \\ \ce \end \ce \\ \ce \begin \ce \\ \ce \end \ce \end Fission properties The fission of one atom of uranium-235 releases () inside the reactor. That corresponds to 19.54 TJ/ mol, or 83.14 TJ/kg. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Critical Mass
In nuclear engineering, a critical mass is the smallest amount of fissile material needed for a sustained nuclear chain reaction. The critical mass of a fissionable material depends upon its nuclear properties (specifically, its nuclear fission cross-section), density, shape, enrichment, purity, temperature, and surroundings. The concept is important in nuclear weapon design. Explanation of criticality When a nuclear chain reaction in a mass of fissile material is self-sustaining, the mass is said to be in a ''critical'' state in which there is no increase or decrease in power, temperature, or neutron population. A numerical measure of a critical mass is dependent on the effective neutron multiplication factor , the average number of neutrons released per fission event that go on to cause another fission event rather than being absorbed or leaving the material. When ''k'' = 1, the mass is critical, and the chain reaction is self-sustaining. A ''subcritical'' mass is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Birmingham
, mottoeng = Through efforts to heights , established = 1825 – Birmingham School of Medicine and Surgery1836 – Birmingham Royal School of Medicine and Surgery1843 – Queen's College1875 – Mason Science College1898 – Mason University College1900 – gained university status by royal charter , city = Birmingham , province = West Midlands , country = England, UK , coor = , campus = Urban, suburban , academic_staff = 5,495 (2020) , administrative_staff = , head_label = Visitor , head = The Rt Hon Penny Mordaunt MP , chancellor = Lord Bilimoria , vice_chancellor = Adam Tickell , type = Public , endowment = £134.5 million (2021) , budget = £774.1 million (2020–21) , students = () , undergrad = () , postgrad = () , affiliations = Universitas 21Universities UK EUA ACUSutton 13Russell Group , free_label = , free = , colours = The University , website = , logo = The University of Birmingham (informally Birmingham University) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudolf Peierls
Sir Rudolf Ernst Peierls, (; ; 5 June 1907 – 19 September 1995) was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allied nuclear bomb programme. His obituary in ''Physics Today'' described him as "a major player in the drama of the eruption of nuclear physics into world affairs". Peierls studied physics at the University of Berlin, at the University of Munich under Arnold Sommerfeld, the University of Leipzig under Werner Heisenberg, and ETH Zurich under Wolfgang Pauli. After receiving his DPhil from Leipzig in 1929, he became an assistant to Pauli in Zurich. In 1932, he was awarded a Rockefeller Fellowship, which he used to study in Rome under Enrico Fermi, and then at the Cavendish Laboratory at the University of Cambridge under Ralph H. Fowler. Because of his Jewish background, he elected to not return home after Adolf Hitler's rise to power in 1933, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Bomb
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions (thermonuclear bomb), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). A thermonuclear weapon weighing as little as can release energy equal to more than . A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been deployed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Frisch
Otto Robert Frisch FRS (1 October 1904 – 22 September 1979) was an Austrian-born British physicist who worked on nuclear physics. With Lise Meitner he advanced the first theoretical explanation of nuclear fission (coining the term) and first experimentally detected the fission by-products. Later, with his collaborator Rudolf Peierls he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940. Early life Frisch was born in Vienna in 1904 to a Jewish family, the son of Justinian Frisch, a painter, and Auguste Meitner Frisch, a concert pianist. He himself was talented at both but also shared his aunt Lise Meitner's love of physics and commenced a period of study at the University of Vienna, graduating in 1926 with some work on the effect of the newly discovered electron on salts. Nuclear physics After some years working in relatively obscure laboratories in Germany, Frisch obtained a position in Hamburg under the Nobel Prize-winning scientist Otto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
