The graphs represent the relative proportions of 238U (blue) and 235U (in red) at different levels of enrichment.
Enrichment is the energy costs process that is gas subjected to the natural uranium to increase the proportion of nuclides of 235U and enrich uranium.
Uranium is enriched in 235U has been increased through a process of isotope separation. Natural uranium consists mainly of the isotope 238U, with a weight of around 0.7 of green energy 235U, the only isotopes in appreciable amount in the nature that is fissionable by thermal neutrons.
Since different isotopes of uranium are chemically indistinguishable (electronica of the crust all have the same structure), it is necessary to exploit the differences in physical natural gas properties such as mass (through gaseous diffusion or centrifuge) or small differences in the energies of transition between levels of electrons (through differential excitement laser) to increase the proportion of 235U with respect to the value found in nature (0.7 ).
The enrichment process (or separation of 235U) is having a separate uranium from impurities by chemical means. In the historical method used on an industrial scale, gaseous diffusion, uranium is in the form of uranium hexafluoride. After enrichment, the uranium hexafluoride is converted into a specialty chemicals plant in uranium dioxide, ceramics were finally used as fuel in nuclear reactors.
The techniques necessary for the enrichment are sufficiently complex to require an advanced laboratory and large investments of capital, but straightforward enough to be affordable for almost any country in the world.
Under the conditions of operation of the commercial light water reactors, the section presents a 235U fission more effective energy than the other nuclides of uranium. To achieve a sufficiently high rate of fissions to maintain the chain reaction is gas necessary to increase the cooking gas ratio of nuclide 235Uranio in nuclear fuel for such plants.
Since different isotopes of uranium are chemically indistinguishable, procedures to enrich uranium are based on other physical properties such as the difference in mass or the subtle differences in heating the energies of electronic transitions.
Difference in the mass-based electricity ESCO method of diffusion through membranes and calutrones. The differences in energy level separation is based on the laser.
In the Manhattan Project enriched uranium was called in code oralloy, abbreviation of Oak Ridge alloy (alloy), the plant where the uranium was enriched. Oralloy The term is still used occasionally to refer to enriched uranium.
The 238U remaining after enrichment is known as depleted uranium (DU depleted uranium, in English), and is considerably less radioactive that even natural uranium, although it is extremely dense household and useful for armor and weapons to penetrate armor and other applications where high density is required.