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Depleted uranium has an even higher concentration of 238 U, and even low-enriched uranium (LEU) is still mostly 238 U. Reprocessed uranium is also mainly 238 U, with about as much uranium-235 as natural uranium, a comparable proportion of uranium-236, and much smaller amounts of other isotopes of uranium such as uranium-234, uranium-233, and ...
The concentration of uranium in soil ranges from 0.7 to 11 parts per million (up to 15 parts per million in farmland soil due to use of phosphate fertilizers), [63] and its concentration in sea water is 3 parts per billion. [22]
Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.
The 0.72% uranium-235 is not sufficient to produce a self-sustaining critical chain reaction in light water reactors or nuclear weapons; these applications must use enriched uranium. Nuclear weapons take a concentration of 90% uranium-235, and light water reactors require a concentration of roughly 3% uranium-235. [3]
It has the chemical symbol U and atomic number 92. The most common isotopes in natural uranium are 238 U (99.274%) and 235 U (0.711%). All uranium isotopes present in natural uranium are radioactive and fissionable, and 235 U is fissile (will support a neutron-mediated chain reaction). Uranium, thorium, and one radioactive isotope of potassium (40
Depleted uranium has an even higher concentration of the 238 U isotope, and even low-enriched uranium (LEU), while having a higher proportion of the uranium-235 isotope (in comparison to depleted uranium), is still mostly 238 U. Reprocessed uranium is also mainly 238 U, with about as much uranium-235 as natural uranium, a comparable proportion ...
Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235 U) has been increased through the process of isotope separation.Naturally occurring uranium is composed of three major isotopes: uranium-238 (238 U with 99.2732–99.2752% natural abundance), uranium-235 (235 U, 0.7198–0.7210%), and uranium-234 (234 U, 0.0049–0.0059%).
This is because 238 U is much more stable than 235 U or 234 U, as the half-life of each isotope reveals: 4.468 × 10 9 years for 238 U compared with 7.038 × 10 8 years for 235 U and 245,500 years for 234 U. Exactly because the different uranium isotopes have different half-lives, when the Earth was younger, the isotopic composition of uranium ...