The Technology of Nuclear Weapons
To manufacture a nuclear weapon, the main requirement is to obtain a sufficient quantity of fissionable or fissile material.1 A fissile element is one whose nucleus is capable of rupture into two lighter fragments, thus forming nuclei of lighter elements, together with free neutrons. These free neutrons may strike other nuclei causing further fission and so on in a chain reaction. The minimum amount of material necessary to sustain a chain reaction is called the critical mass of the substance. Smaller amounts of fissile material will not sustain a chain reaction since too large a fraction of the free neutrons escape through the surface and are unavailable to cause fission in other nuclei. The critical mass can be reduced, however, if the fissile material is compacted to make it more dense, or if it is surrounded by a shell of metallic material such as beryllium (Be) to reflect neutrons which would otherwise escape. If there is enough fissile material, packed closely together for long enough, and if the chain reaction is out of control, the result is a nuclear explosion: an ‘atomic bomb’, the explosive yield of which is equivalent to that of 20 kilotons of TNT. Alternatively, the power from a controlled chain reaction in a nuclear reactor can be used to generate electricity.
KeywordsInternational Atomic Energy Agency Nuclear Weapon Fuel Cycle Enrich Uranium Fissile Material
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Notes and References
- 1.For an introduction to the technology of nuclear weapons and nuclear power, see: Ted Greenwood, George W. Rathjens and Jack Ruina, Nuclear Power and Weapons Proliferation, Adelphi Papers no. 130 (London: International Institute for Strategic Studies, 1976);Google Scholar
- or J. Rotblat, ‘Nuclear Energy and Nuclear Weapon Proliferation’, in Stockholm International Peace Research Institute, Nuclear Energy and Nuclear Weapons Proliferation (London: Taylor & Francis, 1979).Google Scholar
- 2.International Atomic Energy Agency, IAEA Safeguards Glossary (Vienna: IAEA, 1980) p. 21, para 89.Google Scholar
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- and a comparison of similar estimates in Thomas W. Graham, ‘The Economics of Producing Nuclear Weapons in “Nth” countries’, in Dagobert L. Brito, Michael D. Intriligator and Adele E. Wick (eds), Strategies for Managing Nuclear Proliferation (Lexington, Mass: D.C. Heath and Co., 1983) pp. 12–14.Google Scholar
- 8.Stephen M. Meyer, The Dynamics of Nuclear Proliferation (University of Chicago Press, 1984) p. 27;Google Scholar
- George H. Quester, ‘The Politics of Twenty Nuclear Powers’, in Richard Rosecrance (ed.), The Future of the International Strategic System (San Francisco: Chandler, 1972) pp. 73–4;Google Scholar
- Kenneth N. Waltz, The Spread of Nuclear Weapons: More May Be Better, Adelphi Papers no. 171 (London: International Institute for Strategic Studies, 1981) pp. 14–15.Google Scholar
- 13.J. C. Hopkins, ‘Nuclear Weapon Technology’, in Stockholm International Peace Research Institute, Nuclear Proliferation Problems (Cambridge, Mass: The MIT Press, 1974) p. 114.Google Scholar