Search results
Results from the WOW.Com Content Network
Doppler broadening of 238 U's neutron absorption resonances, increasing absorption as fuel temperature increases, is also an essential negative feedback mechanism for reactor control. Around 99.284% of natural uranium's mass is uranium-238, which has a half-life of 1.41 × 10 17 seconds (4.468 × 10 9 years, or 4.468 billion years). [1]
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds. [1]
232 U ƒ: 238 Pu ƒ: 243 Cm ƒ: 29–97 a: 137 Cs 151 Sm þ: 121m Sn 249 Cf ƒ: 242m Am ƒ: 141–351 a No fission products have a half-life in the range of 100 a–210 ka ... 241 Am ƒ: 251 Cf ƒ [4] 430–900 a 226 Ra № 247 Bk 1.3–1.6 ka 240 Pu 229 Th 246 Cm ƒ: 243 Am ƒ: 4.7–7.4 ka 245 Cm ƒ: 250 Cm 8.3–8.5 ka 239 Pu ƒ: 24.1 ka 230 ...
Uranium-234 is a member of the uranium series and occurs in equilibrium with its progenitor, 238 U; it undergoes alpha decay with a half-life of 245,500 years [7] and decays to lead-206 through a series of relatively short-lived isotopes. Uranium-233 undergoes alpha decay with a half-life of 160,000 years and, like 235 U, is fissile. [12]
234 U occurs in natural uranium as an indirect decay product of uranium-238, but makes up only 55 parts per million of the uranium because its half-life of 245,500 years is only about 1/18,000 that of 238 U. The path of production of 234 U is this: 238 U alpha decays to thorium-234. Next, with a short half-life, 234 Th beta decays to ...
It is only weakly radioactive because of the long radioactive half-life of 238 U (4.468 × 10 9 or 4,468,000,000 years) and the low amounts of 234 U (half-life about 246,000 years) and 235 U (half-life 700 million years). The biological half-life (the average time it takes for the human body to eliminate half the amount in the body) for uranium ...
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%).
U238 or U-238 may be: German submarine U-238, a German World War II U-boat (submarine) Uranium-238 (U-238 or 238 U), the most common isotope of uranium