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- Uranium-234 abstract "Uranium-234 is an isotope of uranium. In natural uranium and in uranium ore, U-234 occurs as an indirect decay product of uranium-238, but it makes up only 0.0055% (55 parts per million) of the raw uranium because its half-life of just 245,500 years is only about 1/18,000 as long as that of U-238. The path of production of U-234 via nuclear decay is as follows: U-238 nuclei emit an alpha particle to become thorium-234 (Th-234). Next, with a short half-life, Th-234 nuclei emit a beta particle to become protactinium-234 (Pa-234). Finally, Pa-234 nuclei emit another beta particle to become U-234 nuclei.U-234 nuclei usually last for hundreds of thousands of years, but then they decay by alpha emission to thorium-230, except for the small percentage of nuclei which undergo spontaneous fission. Extraction of rather small amounts of U-234 from natural uranium would be feasible using isotope separation, similar to that used for regular uranium-enrichment. However there is no real demand in chemistry, physics, or engineering for isolating U-234. Very small pure samples of U-234 can be extracted via the chemical ion-exchange process - from samples of plutonium-238 that have been aged somewhat to allow some decay to U-234 via alpha emission.Enriched uranium contains more U-234 than natural uranium as a byproduct of the uranium enrichment process aimed at obtaining U-235, which concentrates lighter isotopes even more strongly than it does U-235. The increased percentage of U-234 in enriched natural uranium is acceptable in current nuclear reactors, but (re-enriched) reprocessed uranium might contain even higher fractions of U-234, which is undesirable. This is because U-234 is not fissile, and tends to absorb slow neutrons in a nuclear reactor - becoming U-235. U-234 has a neutron-capture cross-section of about 100 barns for thermal neutrons, and about 700 barns for its resonance integral - the average over neutrons having various intermediate energies. In a nuclear reactor non-fissile isotopes capture a neutron breeding fissile isotopes. U-234 is converted to U-235 more easily and therefore at a greater rate than U-238 is to Pu-239 (via neptunium-239) because U-238 has a much smaller neutron-capture cross-section of just 2.7 barns. However, (n, 2n) reactions with fast neutrons also convert small amounts of U-235 to U-234, so that spent nuclear fuel may contain about 0.010% U-234, a much higher fraction than in non-irradiated uranium.Depleted uranium contains much less U-234 (around 0.001% ) which makes the radioactivity of depleted uranium about one-half of that of natural uranium. Natural uranium has an "equilibrium" concentration of U-234 at the point where an equal number of decays of U-238 and U-234 will occur. Depleted uranium also contains less U-235, but in spite of its half-life that is much shorter than the one of U-238, the concentration of U-235 in natural uranium is low enough (about 0.7%) so that the U-235 depletion does not result in a significant reduction in radioactivity.".
- Uranium-234 wikiPageID "1898583".
- Uranium-234 wikiPageRevisionID "541125913".
- Uranium-234 abundance "0.0054".
- Uranium-234 after Isotopes_of_thorium.
- Uranium-234 background "#fc6".
- Uranium-234 before Plutonium-238.
- Uranium-234 before "neptunium-234".
- Uranium-234 before "protactinium-234".
- Uranium-234 decayMass "230".
- Uranium-234 decayMode Alpha_decay.
- Uranium-234 decayMode Spontaneous_fission.
- Uranium-234 decayProduct "thorium-230".
- Uranium-234 decaySymbol "Th".
- Uranium-234 element "uranium".
- Uranium-234 halflife "7.7631696E12".
- Uranium-234 hasPhotoCollection Uranium-234.
- Uranium-234 heavier Uranium-235.
- Uranium-234 isotopeName "uranium-234".
- Uranium-234 lighter Uranium-233.
- Uranium-234 massNumber "234".
- Uranium-234 numNeutrons "142".
- Uranium-234 numProtons "92".
- Uranium-234 parent "plutonium-238".
- Uranium-234 parent "protactinium-234".
- Uranium-234 parent "uranium-238".
- Uranium-234 parent2Decay "b-".
- Uranium-234 parent2Mass "234".
- Uranium-234 parent2Symbol "Pa".
- Uranium-234 parent3Decay "a".
- Uranium-234 parent3Mass "238".
- Uranium-234 parent3Symbol "Pu".
- Uranium-234 parentDecay "alpha, beta, beta".
- Uranium-234 parentMass "238".
- Uranium-234 parentSymbol "U".
- Uranium-234 symbol "U".
- Uranium-234 subject Category:Actinides.
- Uranium-234 subject Category:Fertile_materials.
- Uranium-234 subject Category:Isotopes_of_uranium.
- Uranium-234 comment "Uranium-234 is an isotope of uranium. In natural uranium and in uranium ore, U-234 occurs as an indirect decay product of uranium-238, but it makes up only 0.0055% (55 parts per million) of the raw uranium because its half-life of just 245,500 years is only about 1/18,000 as long as that of U-238. The path of production of U-234 via nuclear decay is as follows: U-238 nuclei emit an alpha particle to become thorium-234 (Th-234).".
- Uranium-234 label "Uranium 234".
- Uranium-234 label "Uranium-234".
- Uranium-234 label "Uranium-234".
- Uranium-234 label "Urânio-234".
- Uranium-234 label "Уран-234".
- Uranium-234 sameAs Uranium_234.
- Uranium-234 sameAs Uranium-234.
- Uranium-234 sameAs Urânio-234.
- Uranium-234 sameAs m.064plb.
- Uranium-234 sameAs Q2153640.
- Uranium-234 sameAs Q2153640.
- Uranium-234 wasDerivedFrom Uranium-234?oldid=541125913.
- Uranium-234 isPrimaryTopicOf Uranium-234.