one (pagement installations.ilot) conditioning plant at GorlebenĪre being operated as spent nuclear fuel management installations.Ī multi-stage search procedure to find the best possible site for a repository for high-level radioactive waste in Germany is taking place under the supervision of BASE.central and decentralised fuel element interim storage facilities and.Since 2005, the law permits only the direct disposal of spent fuel elements in Germany. For this purpose, the fuel elements are disassembled in a conditioning plant, placed into waste packages suitable for disposal and then disposed of as radioactive waste. In direct disposal, the entire fuel element including the uranium and plutonium still contained therein is disposed of as radioactive waste after it has been stored intermediately in order for the short-lived radionuclides to decay and to reduce the heat generation that comes with the decay. The radioactive fission products are solidified and then stored as radioactive waste. Before they can be reused in a nuclear power plant, plutonium and uranium need to be reprocessed again to fuel elements. When they are reprocessed subsequently, reusable uranium and plutonium are separated from the radioactive fission products. The fuel elements are initially taken to an interim storage facility, where their activity decays. Reprocessing including recovery and reuse of the usable shares of plutonium and uranium:.
Two types of spent fuel element management are pursued: All activities to treat, reprocess and dispose of the spent fuel elements are collectively referred to as spent nuclear fuel management. Due to the nuclear fissions, the share of the fissile U-235 decreases and radioactive fission products and significant amounts of plutonium generate, which is a new nuclear fuel. Generally, fuel elements are used in reactors for three to four years.
one fuel element fabrication plant at Lingen.In Germany, the following nuclear fuel supply plants are in operation: Fuel elements of a pressurised water reactor contain about 500 kg uranium, those of a boiling-water reactor contain about 200 kg uranium. This way single fuel rods are obtained that are assembled to fuel elements. Tablets are pressed from UO 2 powder that are sintered at temperatures above 1,700 ☌, filled into cladding tubes made from zirconium alloys, and sealed gas-tight. In a fuel element fabrication plant the uranium hexafluoride is converted into uranium dioxide (UO 2). The product of the enrichment plant is UF 6 whose U-235 share is ca. Enrichment methods use the slight difference in mass of the U-235 and U-238 molecules of the UF 6 to separate these two components. Only in the gas phase is it easy to enrich the uranium. For this purpose, the uranium is converted into the chemical compound uranium hexafluoride (UF 6) which can easily be transferred into the gas phase. Therefore the isotope U-235 needs to be concentrated (“enriched”) in the uranium.
Nuclear power plants with light water reactors need uranium with a share of 3 % to 5 % of the fissile isotope U-235. Enrichment of the uranium isotope U-235 required for nuclear fission in light-water reactors.The natural isotope composition of the uranium contained in the Yellow Cake is 0.7 % U-235 and 99.3% U-238 The commercial product “Yellow Cake” is produced, which contains about 70 % to 75 % of uranium. In a milling procedure the uranium is concentrated. The uranium content of the mined ores is typically 0.2 %. Extraction of the uranium from the rock in milling facilities.
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