Search results
Results from the WOW.Com Content Network
Caesium-137 (137 55 Cs), cesium-137 (US), [7] or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. Trace quantities also originate from spontaneous fission of uranium-238. It is ...
Almost all caesium produced from nuclear fission comes from beta decay of originally more neutron-rich fission products, passing through isotopes of iodine then isotopes of xenon. Because these elements are volatile and can diffuse through nuclear fuel or air, caesium is often created far from the original site of fission.
Decay Scheme of Caesium-137. Based on a public domain image by Kieran Maher (see original image) Date: 31 August 2006: Source: Own work: Author: Dirk Hünniger: Other versions: Derivative works of this file: Caesium-137 Decay Scheme-de-2.svg
The shorter-lived 137m Ba (half-life 2.55 minutes) arises as the decay product of the common fission product caesium-137. Barium-114 is predicted to undergo cluster decay, emitting a nucleus of stable 12 C to produce 102 Sn. However this decay is not yet observed; the upper limit on the branching ratio of such decay is 0.0034%.
Caesium-135 is a long-lived fission product with much weaker radioactivity. Neutron capture inside the reactor transmutes much of the xenon-135 that would otherwise decay to Cs-135. Caesium-137, with a half-life of 30 years, is the main medium-lived fission product, along with Sr-90.
The accompanying decay scheme diagram shows the beta decay of caesium-137. 137 Cs is noted for a characteristic gamma peak at 661 keV, but this is actually emitted by the daughter radionuclide 137m Ba. The diagram shows the type and energy of the emitted radiation, its relative abundance, and the daughter nuclides after decay.
Date/Time Thumbnail Dimensions User Comment; current: 13:42, 28 August 2011: 624 × 345 (14 KB): Kalin.KOZHUHAROV: added color and made consistent use of styles: 10:22, 26 March 2011
It is commonly believed that, with the rate of the current radionuclide leakage, the dispersal into the water would prove beneficial, as most of the isotopes would be diluted by the water as well as become less radioactive over time, due to radioactive decay. Cesium (Cs-137) is the primary isotope released from the Fukushima Daiichi facility. [160]