Breeder nuclear reactors

Nuclear Fusion Nuclear Fission Nuclear Reactors Breeder Reactors Fusion... 

Molten lithium fluoride is used in salt mixtures for an electrolyte in high temperature batteries (qv) (FLINAK) (20), and as a carrier in breeder reactors (FLIBE) (21) (see Nuclear reactors). 

Boron-10 has a natural abundance of 19.61 atomic % and a thermal neutron cross section of 3.837 x 10 m (3837 bams) as compared to the cross section of 5 x 10 m (0.005 bams). Boron-10 is used at 40—95 atomic % in safety devices and control rods of nuclear reactors. Its use is also intended for breeder-reactor control rods. 

A variation of the classical fuel cycle is the breeder cycle. Special breeder reactors are used to convert fertile isotopes iato fissile isotopes, which creates more fuel than is burned (see Nuclear reactors, reactor types). There are two viable breeder cycles U/ Pu, and Th/ U. The thorium fuels were, however, not ia use as of 1995. A breeder economy implies the existence of both breeder reactors that generate and nonbreeder reactors that consume the fissile material. The breeder reactor fuel cycle has been partially implemented ia France and the U.K. 

Fast Breeder Reactors" uader "Nuclear Reactors" ia ECT3rd ed., VoL 16, pp. 184—205, by P. Murray, Westiaghouse Electric Corp. 

Many of the fission products formed in a nuclear reactor are themselves strong neutron absorbers (i.e. poisons ) and so will stop the chain reaction before all the (and Pu which has also been formed) has been consumed. If this wastage is to be avoided the irradiated fuel elements must be removed periodically and the fission products separated from the remaining uranium and the plutonijjm. Such reprocessing is of course inherent in the operation of fast-breeder reactors, but whether or not it is used for thermal reactors depends on economic and political factors. Reprocessing is currently undertaken in the UK, France and Russia but is not considered to be economic in the USA. 

Reviews of analytical methods for impurities in alkali metals are largely devoted to Na and K owing to their use as liquid coolants in fast-breeder nuclear reactors ". These methods may be extended to Rb and Cs except the analysis for oxygen. In analytical work with the alkali metals, care is necessary during sampling and handling to avoid contamination in transit. The impurities usually considered are O, C, N, H and metals. 

Y. S. Tang. Ph.D has more than 35 years of experience in the field of thermal and fluid flow. His research interests have covered aspects of thermal hydraulics that are related to conventional and nonconventional power generation systems, with an emphasis on nuclear reactor design and analysis that focuses on liquld-meta -cooled reactors. Dr. Tang is co-author of Radioactive Waste Management published by Taylor 8 Francis, and Thermal Analysis of Liquid Metal Fast Breeder Reactors, He received a B5. from National Central University In China and an MS. in mechanical engineering from the University of Wisconsin. He earned his Ph.D. 

Nuclear fission power plants were at one time thought to be the answer to diminishing fossil fuels. Although the enriched uranium fuel was also limited, an advanced nuclear reactor called breeders would be able to produce more radioactive fuel, in the form of plutonium, than consumed. This would make plutonium fuel renewable. Although plutonium has been called one of the most toxic elements known, it is similar to other radioactive materials and requires careful handling since it can remain radioactive for thousands of years. 

Conventional nuclear reactors and advanced breeder reactors were America s primary energy strategy since the 1950s to resolve the fossil fuel problem but when a reactor accident occurred in 1979 at Three Mile Island in Pennsylvania, public and investor confidence in nuclear fission dropped. The accident was triggered by the failure of a feedwater pump that supplied water to the steam generators. The backup feedwater pumps were not connected to the system as required, which caused the reactor to heat up. The safety valve then failed to act which allowed a radioactive water and gas leak. This was the worst nuclear power accident in the U.S., but in this accident no one was killed and no one was directly injured. At Three Mile Island faulty instrumentation gave incorrect readings for the... 

In the light of the projected growth of demand for energy services, particularly electricity, there is a renewed interest in the extension of nuclear power in some countries. With uranium being a finite resource as well, Chapter 4 focuses primarily on the question of a future expansion of nuclear power in the context of the availability of nuclear fuels. Moreover, the evolution of the next generation of nuclear reactors, such as breeder reactors or reactors suitable for hydrogen production, is addressed. 

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. 

I0.6.8.I Cladding failure in oxide fuel pins of nuclear reactors. The long-term operational performance of nuclear fuel pins is critically governed by the reactions that occur in the gap between the fuel and its cladding. Ball et al. (1989) examined this for the cases of (1) Zircaloy-clad pellets of U02+, in a pressurised water reactor (PWR) and (2) stainless-steel-clad pellets of (U, P)02+, in a liquid-metal-cooled fast-breeder reactor (LMFBR). In particular they were interested in the influence of O potential on Cs, I, Te and Mo and the effects of irradiation on the gaseous species within the fuel-clad gaps. 

Plutonium is produced from natural uranium which is a mixture of nonfis-sionable uranium-238 (99.3%) and fissionable uranium-235(0.7%). The first synthesis of this element was in a cyclotron generating plutonium in microgram quantities. The isotope Pu-239 can be produced in much larger quantities in a nuclear reactor, either a conventional thermal reactor or a breeder type reactor by neutron bombardment of uranium- 238. The nuclear reactions are shown below. 

Breeder reactor is different from nuclear reactor ... 

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... 

Nuclear power is a relatively new source of energy. The first electrical power production from a nuclear reactor occurred on 20 December, 1951, in Idaho at the Experimental Breeder Reactor Number 1 (EBR-1), and since that time nuclear science and technology have had a tremendous impact on the 20th century (Ewing... 

Carbides of the Actinides, Uranium, and Thorium. The carbides of uranium and thorium are used as nuclear fuels and breeder materials for gas-cooled, graphite-moderated reactors (see Nuclear REACTORS). The actinide carbides are prepared by the reaction of metal or metal hydride powders with carbon or preferably by the reduction of the oxides uranium dioxide [1344-57-6], U02, triuranium octaoxide [1344-59-8], U,08, or thorium... 

In plutonium-fueled breeder power reactors, more plutonium is produced than is consumed (see Nuclear REACTORS, reactor types). Thus the utilization of plutonium as a nuclear energy or weapon source is especially attractive to countries that do not have uranium-enrichment facilities. The cost of a chemical reprocessing plant for plutonium production is much less than that of a uranium-235 enrichment plant (see Uraniumand URANIUM compounds). Since the end of the Cold War, the potential surplus of 239Pu metal recovered from the dismantling of nuclear weapons has presented a large risk from a security standpoint. 

In a typical fast breeder nuclear reactor, most of the fuel is 238U (90 to 93%). The remainder of the fuel is in the form of fissile isotopes, which sustain the fission process. The majority of these fissile isotopes are in the form of 239Pu and 241Pu, although a small portion of 235U can also be present. Because the fast breeder converts die fertile isotope 238 U into the fissile isotope 239Pu, no enrichment plant is necessary. The fast breeder serves as its own enrichment plant. The need for electricity for supplemental uses in the fuel cycle process is thus reduced. Several of the early hquid-metal-cooled fast reactors used plutonium fuels. The reactor Clementine, first operated in the Unired States in 1949. utilized plutonium metal, as did the BR-1 and BR.-2 reactors in the former Soviet Union in 1955 and 1956, respectively. The BR-5 in the former Soviet Union, put into operation in 1959. utilized plutonium oxide and carbide. The reactor Rapsodie first operated in France in 1967 utilized uranium and plutonium oxides. 

The isotopes of thorium include mass numbers 223-234. 232Th has a half-life of 1.39 x 1010 years, See also Radioactivity. It emits an alpha-particle and forms meso-thorium 1 (radium-228), which is also radioactive, having a half-life of 6.7 years, emitting a beta-particle. Since 2 2Th captures slow neutions to form, by a series of nuclear reactions, >>U which is fissionable, thorium can be used as a fuel for nuclear reactors of the breeder type. Thorium occurs in earth minerals, an average content estimated at about 12 ppm. Findings of hc Apollo 11 space flight indicated that thorium concentrations in some lunar rocks are about the same as the concentrations in terrestrial basalts. 

The most abundant isotope of uranium, 238U, does not undergo fission. In a breeder reactor, however, a 238U atom captures a neutron and emits two /3 particles to make a fissionable isotope of plutonium, which can then be used as fuel in a nuclear reactor. Write a balanced nuclear equation. 

Shortages of oil and coal will be followed by one of uranium. The nuclear industry knows that the fuel of today s thermal nuclear reactors (U235) is exhaustible and therefore in a few decades they plan to shift to breeder reactors. They say little to the public, except that this conversion would make nuclear power inexhaustible. This is true, because the conventional "slow neutron" thermal reactors are "once through" (in the sense that they consume their uranium fuel), while fast neutron breeder reactors make more fuel than they use. 

Although, at the end of the twentieth century, the accident at Chernobyl has made the use of fission reactors (eventually breeders) politically unacceptable, it must be recalled that our society can be run on electricity from nuclear reactors, with hydrogen as the storage medium and fuel for transportation. Fail-safe reactor schemes have been described in the literature. The eventual choice between nuclear energy and renewables will be one of cost. 

Yb-169 Used during brain scans U-235 Fuel for most nuclear reactors Pu-239 Used in nuclear weapons, fast breeder reactors, and MOX fuel reactors Am-241 Used in smoke detectors... 

It should be noted that breeders would not reduce the demand for uranium ore for many decades because several LWR and/or HWR converters (which produce fissionable material, but less than consumption) are required during the run-in of a breeder cycle to equilibrium. The doubling time of a breeder (the time required for the breeder to produce sufficient fissionable material to start up a second breeder reactor) might be a significant part of its operating life. Furthermore, natural uranium will be required for the thorium cycle, if it is used, and for startup of the fusion cycle. The tritium for the fusion cycle will be made in nuclear reactors, as it now is for nuclear weapons. The nuclear industry will always be dependent on a continuing supply of uranium from ore. 

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