Plutonium-239, fissioning

A nuclear reactor produces electricity by harnessing the energy released during the splitting, or fission, of a heavy isotope, such as uranium-235 or plutonium-239. Fission can be induced when the nucleus of one of these isotopes absorbs a free neutron. When the isotope fissions, it generally splits into two smaller isotopes (referred to as fission products) and releases two or three neutrons and about 200 MeV of energy, about 20 million times the energy released... 

Argon-40 [7440-37-1] is created by the decay of potassium-40. The various isotopes of radon, all having short half-Hves, are formed by the radioactive decay of radium, actinium, and thorium. Krypton and xenon are products of uranium and plutonium fission, and appreciable quantities of both are evolved during the reprocessing of spent fuel elements from nuclear reactors (qv) (see Radioactive tracers). 

TEA chloride See tetraethylammonium chloride., te,e a klorjd ) technetium chem A transition element, symbol Tc, atomic number 43 derived from uranium and plutonium fission products chemically similar to rhenium and manganese isotope Tc has a half-life of 200,000 years used to absorb slow neutrons in reactor technology. tek ne-she-om ... 

Meanwhile, work was being carried out to determine the parent of the supposed fission xenon component. In 1971, Calvin Alexander, working at Berkeley, measured the isotopic composition of a sample of plutonium that had been produced by a nuclear reactor. The sample was heated to release all trapped gases and then left on a shelf for 23 months to allow pure plutonium fission xenon to accumulate. The resulting precise composition of plutonium fission xenon eliminated plutonium as the parent of CCFXe. Another hypothesis, championed by Edward Anders of the University of Chicago, was that the CCFXe had been produced by fission of a super-heavy element. Nuclear physicists had presented theoretical... 

Kunz, I, Staudacher, T., Allegre, C. J. (1998) Plutonium-fission Xe found in Earth s mantle. Science, 280, 877-80. 

TATB is a thermally stable and remarkable explosive with many stable characteristics including shock, percussion, and friction insensitivity. It can be heated to 260 Celsius without any decomposition, but if contaminated with impurities a small sample will decompose rapidly and violently at 260 Celsius. TATB can be melted and alloyed with TNT, RDX, HMX, and solex for making hollow charges, and for filling explosive shells. One interesting characteristic of TATB is that it s used in nuclear weapons to initiate plutonium fission. ... 

The properties of isotopes. Packing fraction. Structure of atomic nuclei. Nuclear fission. Nuclear chain reaction. Manufacture of plutonium. Fission of U23 and Pu23 . Uranium reactors the uranium pile. Nuclear energy as a source of power. 

The destructive power of nuclear weapons derives from the core of the atom, the nucleus. One type of nuclear weapon, the fission bomb, uses the energy released when nuclei of heavy elements such as plutonium fission (split apart). A second even more powerful type of nuclear weapon, the fusion or hydrogen bomb, uses the energy released when nuclei of hydrogen are united (fused together). 

A reactor startirig with 3 % U produces 6000 MWd enetgy/t U fiiel each year. Neglecting fission in U, (a) how much fission products have been produced after 5 years (b) What is the U concentration if plutonium fission also is taken into account ... 

The thermal power is 450 MW. For "° Ag inventory calculation, plutonium fission fraction and thermal flux are assumed to be 60% and 4x lO cm s , respectively. Fractional release from fuel... 

The calculated result of " Ag inventory in GT-HTGR core showed that with higher bumup, higher power density and longer irradiation time, plutonium fission fitiction, thermal flux and irradiation time in GT-HTGR core could be about 70 times larger than that of HTTR. 

From an environmental viewpoint, fusion power is much cleaner than fission power because fusion reactions (in contrast to uranium and plutonium fission reactions) do not produce large amounts of long-lived and dangerously radioactive isotopes. 

Conventional LWRs alone cannot be used to transmute minor actinides because thermal neutrons are not as effective for inducing the fission reaction. As a result, nfinor actinides (especially, non-fissile even isotopes of plutonium) build up as a function of time. Therefore, thermal reactors tend to preferentially produce minor actinides. Fast reactors or fast neutron spectrum devices on the other hand tend to more effectively destroy the minor actinides because the probability of fission for both the even and odd isotopes of plutonium fission with fast neutrons is considerably higher than with thermal neutrons. Thus, last reactors are heavily preferred for the recycle of plutonium and the ultimate complete destruction of all of the minor actinides. 

With regard to the radionuclide composition of irradiated fuel, there are also deviations from the simple relationship between fission product activity concentrations of longer-lived nuclides and fuel bumup. Similarly to the buildup of the mass concentrations, these deviations are due to the increasing contribution of plutonium fissions to radionuclide production as well as to consumption of long-lived radionuclides by neutron capture in extreme cases, such as with the short-lived... 

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