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To reduce the concentration of Pu-240 in the plutonium produced, weapons program plutonium production reactors (e.g. B Reactor) irradiate the uranium for a far shorter time than is normal for a nuclear power reactor. More precisely, weapons-grade plutonium is obtained from uranium irradiated to a low burnup.
Nuclear reprocessing is the chemical separation of fission products and actinides from spent nuclear fuel. [1] Originally, reprocessing was used solely to extract plutonium for producing nuclear weapons. With commercialization of nuclear power, the reprocessed plutonium was recycled back into MOX nuclear fuel for thermal reactors. [2]
Less than a formula quantity of strategic special nuclear material but more than 1,000 grams of uranium-235 (contained in uranium enriched to 20 percent or more in the U-235 isotope) or more than 500 grams of uranium-233 or plutonium-239, or in a combined quantity of more than 1,000 grams (2.2 pounds) when computed by the equation grams ...
Plutonium–gallium–cobalt alloy (PuCoGa 5) is an unconventional superconductor, showing superconductivity below 18.5 K, an order of magnitude higher than the highest between heavy fermion systems, and has large critical current. [46] [50] Plutonium–zirconium alloy can be used as nuclear fuel. [51]
Assuming the material expands with temperature (enriched uranium-235 at room temperature for example), at an exactly critical state, it will become subcritical if warmed to lower density or become supercritical if cooled to higher density. Such a material is said to have a negative temperature coefficient of reactivity to indicate that its ...
Infrared absorption spectra of the two UF 6 isotopes at 300 and 80 K. Schematic of a stage of an isotope separation plant for uranium enrichment with laser. An infrared laser with a wavelength of approx. 16 μm radiates at a high repetition rate onto a UF6 carrier gas mixture, which flows supersonically out of a laval nozzle.
U will inevitably be enriched slightly stronger than 235 U, which is a negligible effect in a once-through fuel cycle due to the low (55 ppm) share of 234 U in natural uranium but can become relevant after successive passes through an enrichment-burnup-reprocessing-enrichment cycle, depending on enrichment and burnup characteristics. 234
When 3% enriched LEU fuel is used, the spent fuel typically consists of roughly 1% U-235, 95% U-238, 1% plutonium and 3% fission products. Spent fuel and other high-level radioactive waste is extremely hazardous, although nuclear reactors produce orders of magnitude smaller volumes of waste compared to other power plants because of the high ...