Related topics: nuclear plant

New map for radioactive soil contamination in Western Europe

An international consortium of scientists has refined the map of cesium and plutonium radionuclide concentrations in soils in Switzerland and several neighboring countries. Using an archive of European soil samples, the team ...

Single-atom probe uses quantum information for the first time

Sensors collect certain parameters such as temperature and air pressure in their proximity. Physicists from Kaiserslautern and a colleague from Hanover have succeeded for the first time in using a single cesium atom as a ...

Fukushima clean-up reduces radiation levels, but not all

Clean-up efforts at Japan's Fukushima nuclear plant, destroyed by a massive earthquake and tsunami in 2011, have significantly reduced radiation levels but untreated forested areas remain a problem, scientists said Thursday.

Sun, sand, surf and radiation in shadow of Fukushima

With its towering waves, golden sand and stunning scenery, Toyoma beach in Iwaki is an almost perfect spot for surfing—if only it wasn't just down the coast from Japan's leaking Fukushima nuclear power plant.

Particle physics for internal security

ETH spin-off Arktis Radiation Detectors Ltd produces special detectors that are in demand for internal security and combating terrorism. The plan moving forward is to develop a mobile detector within the frame of a research ...

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Caesium or cesium ( /ˈsiːziəm/ see-zee-əm) is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C (82 °F), which makes it one of only five elemental metals that are liquid at (or near) room temperature. Caesium is an alkali metal and has physical and chemical properties similar to those of rubidium and potassium. The metal is extremely reactive and pyrophoric, reacting with water even at −116 °C (−177 °F). It is the least electronegative element that has stable isotopes, of which it has only one, caesium-133. Caesium is mined mostly from pollucite, while the radioisotopes, especially caesium-137, a fission product, are extracted from waste produced by nuclear reactors.

Two German chemists, Robert Bunsen and Gustav Kirchhoff, discovered caesium in 1860 by the newly developed method of flame spectroscopy. The first small-scale applications for caesium have been as a "getter" in vacuum tubes and in photoelectric cells. In 1967, a specific frequency from the emission spectrum of caesium-133 was chosen to be used in the definition of the second by the International System of Units. Since then, caesium has been widely used in atomic clocks.

Since the 1990s, the largest application of the element has been as caesium formate for drilling fluids. It has a range of applications in the production of electricity, in electronics, and in chemistry. The radioactive isotope caesium-137 has a half-life of about 30 years and is used in medical applications, industrial gauges, and hydrology. Although the element is only mildly toxic, it is a hazardous material as a metal and its radioisotopes present a high health risk in case of radiation leaks.

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