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RSS SubscribeTuesday 1st August 2006
Scientists ready for ITER startup
by EC
The Cadarache site in southeast France is preparing for the start-up of the ITER (International Thermonuclear Experimental Reactor) project. As its name states, ITER is a prototype reactor that will experiment under real conditions in generating energy from thermonuclear fusion.
There are two types of nuclear reactions, fission and fusion. In nuclear fission, the nucleus of a heavy atom is split into several lighter nuclides. This releases neutrons and a large amount of energy. This process is used in nuclear power stations that operate on the basis of the fission of plutonium.
Nuclear fusion is still an experimental process: two atomic nuclei are brought together to form a heavier nucleus. Their fusion releases tremendous amounts of energy from the mass defect. For the nuclei to be able to join together, however, they must be in a state of extreme thermal agitation, meaning they are immersed in a “fusion plasma”. This phenomenon occurs naturally in stars, especially in the sun, where hydrogen nuclei fuse to produce helium, releasing huge amounts of heat and light.
This reaction has been reproduced artificially for a number of years in laboratory conditions and military applications (the H bomb). But an experimental reactor had to be developed for fusion to be used to generate energy on an industrial scale. That is precisely the purpose of the ITER project, which will study on a large scale (500 MW) the scientific and technical feasibility of a reactor using Tokamak technology.
The benefits of this process for generating energy are that it releases no greenhouse gases; the basic fuel (deuterium, a hydrogen isotope) is an almost inexhaustible resource since it is available in sea water; and it involves no risk of environmental accidents. Another advantage is that fusion produces only 1⁄100th of the waste produced by fission and the waste has a much shorter life cycle.
This process for the future will be tested in Cadarache from 2016 in an international project bringing together scientific know-how from the European Union, Russia, China, the United States, India, Japan and South Korea.
