Portal:Nuclear Technology
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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.
A nuclear weapon (also called an atom bomb, nuke, atomic bomb, nuclear warhead, A-bomb, or nuclear bomb) is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb). 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 20,000 tons of TNT (84 TJ). The first thermonuclear ("hydrogen") bomb test released energy approximately equal to 10 million tons of TNT (42 PJ). A thermonuclear weapon weighing little more than 2,400 pounds (1,100 kg) can release energy equal to more than 1.2 million tons of TNT (5.0 PJ). A nuclear device no larger than traditional bombs 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 used twice in war, both times by the United States against Japan near the end of World War II. On August 6, 1945, the U.S. Army Air Forces detonated a uranium gun-type fission bomb nicknamed "Little Boy" over the Japanese city of Hiroshima; three days later, on August 9, the U.S. Army Air Forces detonated a plutonium implosion-type fission bomb nicknamed "Fat Man" over the Japanese city of Nagasaki. These bombings caused injuries that resulted in the deaths of approximately 200,000 civilians and military personnel. The ethics of these bombings and their role in Japan's surrender are subjects of debate.

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Groves and Chadwick 830308.jpg
Britain contributed to the Manhattan Project by helping initiate the effort to build the first atomic bombs in the United States during World War II, and helped carry it through to completion in August 1945 by supplying crucial expertise. Following the discovery of nuclear fission in uranium, scientists Rudolf Peierls and Otto Frisch at the University of Birmingham calculated, in March 1940, that the critical mass of a metallic sphere of pure uranium-235 was as little as 1 to 10 kilograms (2.2 to 22.0 lb), and would explode with the power of thousands of tons of dynamite. The Frisch-Peierls memorandum prompted Britain to create an atomic bomb project, known as Tube Alloys. Mark Oliphant, an Australian physicist working in Britain, was instrumental in making the results of the British MAUD Report known in the United States in 1941 by a visit in person. Initially the British project was larger and more advanced, but after the United States entered the war, the American project soon outstripped and dwarfed its British counterpart. The British government then decided to shelve its own nuclear ambitions, and participate in the American project.

In August 1943, the Prime Minister of the United Kingdom, Winston Churchill, and the President of the United States, Franklin D. Roosevelt, signed the Quebec Agreement, which provided for cooperation between the two countries. The Quebec Agreement established the Combined Policy Committee and the Combined Development Trust to coordinate the efforts of the United States, the United Kingdom and Canada. The subsequent Hyde Park Agreement in September 1944 extended this cooperation to the postwar period. A British Mission led by Wallace Akers assisted in the development of gaseous diffusion technology in New York. Britain also produced the powdered nickel required by the gaseous diffusion process. Another mission, led by Oliphant who acted as deputy director at the Berkeley Radiation Laboratory, assisted with the electromagnetic separation process. As head of the British Mission to the Los Alamos Laboratory, James Chadwick led a multinational team of distinguished scientists that included Sir Geoffrey Taylor, James Tuck, Niels Bohr, Peierls, Frisch, and Klaus Fuchs, who was later revealed to be a Soviet atomic spy. Four members of the British Mission became group leaders at Los Alamos. William Penney observed the bombing of Nagasaki and participated in the Operation Crossroads nuclear tests in 1946.

Cooperation ended with the Atomic Energy Act of 1946, known as the McMahon Act, and Ernest Titterton, the last British government employee, left Los Alamos on 12 April 1947. Britain then proceeded with High Explosive Research, its own nuclear weapons programme, and became the third country to test an independently developed nuclear weapon in October 1952.

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Fat Man (National Museum USAF).jpg
Credit: United States Air Force

Casing of a "Fat Man"-style nuclear bomb, painted like the one dropped on Nagasaki.

Did you know?

  • ... that the Soviet destroyer Sposobny was designed to survive a nuclear explosion?
  • ... that organic nuclear reactors, widely researched in the 1950s and 1960s, replaced the water normally used to cool the reactor core with various organic fluids?
  • ... that under terms of the Quebec Agreement, the United States had to seek British agreement to use nuclear weapons against Japan?
  • ... that during the Cuban Missile Crisis, each of Britain's "V force" squadrons kept one nuclear-armed V bomber and crew at 15 minutes' readiness?
  • ... that Project Flying Cloud was expected to affect an area "comparable in size to that affected by a low-yield nuclear weapon"?
  • ... that with his appointment to head the 12th Submarine Squadron, Rear-Admiral Andrei Volozhinsky commanded nearly 14 percent of strategic Russian warheads and 63 percent of Russia's naval strategic nuclear forces?

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Selected biography

Willard Frank Libby (December 17, 1908 - September 8, 1980) was an American physical chemist noted for his role in the 1949 development of radiocarbon dating, a process which revolutionized archaeology and palaeontology. For his contributions to the team that developed this process, Libby was awarded the Nobel Prize in Chemistry in 1960.

A 1927 chemistry graduate of the University of California, Berkeley, from which he received his doctorate in 1933, he studied radioactive elements and developed sensitive Geiger counters to measure weak natural and artificial radioactivity. During World War II he worked in the Manhattan Project's Substitute Alloy Materials (SAM) Laboratories at Columbia University, developing the gaseous diffusion process for uranium enrichment.

After the war, Libby accepted professorship at the University of Chicago's Institute for Nuclear Studies, where he developed the technique for dating organic compounds using carbon-14. He also discovered that tritium similarly could be used for dating water, and therefore wine. In 1950, he became a member of the General Advisory Committee (GAC) of the Atomic Energy Commission (AEC). He was appointed a commissioner in 1954, becoming its sole scientist. He sided with Edward Teller on pursuing a crash program to develop the hydrogen bomb, participated in the Atoms for Peace program, and defended the administration's atmospheric nuclear testing.

Libby resigned from the AEC in 1959 to become Professor of Chemistry at University of California, Los Angeles (UCLA), a position he held until his retirement in 1976. In 1962, he became the Director of the University of California statewide Institute of Geophysics and Planetary Physics (IGPP). He started the first Environmental Engineering program at UCLA in 1972, and as a member of the California Air Resources Board, he worked to develop and improve California's air pollution standards.

Nuclear technology news

12 January 2020 -
The government of the Canadian province of Ontario apologizes for issuing a false alert about an incident at a nuclear plant near Toronto and blames a training exercise mistake. Angry local mayors demand an inquiry, saying the emergency message about the ageing Pickering Nuclear Generating Station has caused unnecessary distress. (Reuters)
11 January 2020 - North Korea-United States relations
After U.S. President Donald Trump sends birthday wishes to North Korean leader Kim Jong-un, North Korea state media says that "although Chairman Kim Jong-un has good personal feelings about President Trump, they are, in the true sense of the word, 'personal'", and that it is not enough to resume denuclearization talks. It further stated that the country would not be led on the basis of Kim's feelings. (Reuters) (BBC)
5 January 2020 - 2019-20 Persian Gulf crisis
After the United States kills Iranian General Qasem Soleimani in the 2020 Baghdad International Airport airstrike, Iran's parliament votes to exit the 2015 Joint Comprehensive Plan of Action nuclear deal with world powers. This comes after the United States unilaterally withdrew in 2018. (MSN)
1 January 2020 - North Korea-United States relations, North Korea and weapons of mass destruction
North Korean leader Kim Jong-un says his nation will be "developing a new strategic weapon" in the near future, after the United States misses a year-end deadline for a restart of denuclearization talks. (Reuters)

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