Fission plutonium

The most common use of uranium is to convert the rare isotope U-235, which is naturally fissionable, into plutonium through neutron capture. Plutonium, through controlled fission, is used in nuclear reactors to produce energy, heat, and electricity. Breeder reactors convert the more abundant, but nonfissionable, uranium-238 into the more useful and fissionable plutonium-239, which can be used for the generation of electricity in nuclear power plants or to make nuclear weapons. 

Uranium-235 is the most important uranium isotope for nuclear fuel. Uranium-238, although not fissionable itself, can be converted into the fissionable plutonium-239 in a breeder reactor by the following nuclear reaction ... 

Bose-Einstein Condensate phase of matter that is created just above absolute zero when atoms lose their individual identity Boyle s Law law that states volume of a gas is inversely related to its pressure Breeder Reactor type of nuclear reactor that creates or breeds fissionable plutonium from nonfissionable U-238 Buckministerfullerene Cg, allotrope of carbon consisting of spherical arrangement of carbon, named after architect Buckmin-ister Fuller, Invertor of geodesic dome Buffer a solution that resists a change in pH... 

One of the fascinating features of fission power is the breeding of fission fuel from nonfissionable uranium-238. Breeding occurs when small amounts of fissionable isotopes are mixed with uranium-238 in a reactor. Fission liberates neutrons that convert the relatively abundant nonfissionable uranium-238 to uranium-239, which beta-decays to neptunium-239, which in turn beta-decays to fissionable plutonium-239. So in addition to the abundant energy produced, fission fuel is bred from relatively abundant uranium-238 in the process. 

Scientists later discovered a third isotope, plutonium-239, also could undergo nuclear fission. Plutonium-239 does not occur in nature but can be made synthetically in nuclear reactors and particle accelerators. 

Breeder reactors, on the other hand, can convert virtually all of U-238 into fissionable plutonium, producing about 140 times more energy than burners, and 70 times more than low-conversion ratio reactors. 

Preparation experiments and solubility tests for (Ui xPUx)02 (0.25 < X < 0.65) and for(Ui.xPux)N (0,25possible materials for the efficient fission Plutonium in a fast neutron flux (CEA/CAPRA)... 

The first power-producing reactor in the United States was a sodium-cooled fast reactor, EBR-I. Fast neutron based reactors are able to utilize the LP as well as the U as fuel. In addition, they are able to produce more fissionable plutonium than they burn. In a cover letter to a study commissioned by President Kennedy in 1962, Atomic Energy Commission Chairman Glenn T. Seaborg wrote the following ... 

Aniver Xes - Both fhst and slow neutrons will fission plutonium. 

A limitation of fission reactors is the fact that only 0.71% of natural uranium is fissionable uranium-235. This situation could be improved by the development of breeder reactors, which convert uranium-238 (natural abundance 99.28%) to fissionable plutonium-239. 

Plutonium-239 is also fissionable. Plutonium is preferred for nuclear weapons for at least two reasons ... 

Breeder reactors convert nonfissionable into fissionable Pu. The material used for fission is a combination of U-235 (which undergoes fission in a chain reaction) and the more common U-238 isotope. Excess neutrons from the U-235 fission are absorbed by the U-238, converting it to the fissionable plutonium isotope Pu-239. The chemical and physical properties of Pu-239 make it very difficult and expensive to handle and process. 

Reactors previously built and now in use in Britain — two at Harwell and two at Sellafield — use uranium rods enclosed in graphite which acts as a moderator to slow down neutrons produced by fission. Plutonium is created by such piles and those at Sellafield were built for this purpose, but the principle of breeding is to create more fissile material than is consumed. 

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