Availability of Uranium

The annual demand for uranium is currently just over 60 10- t (1994 62 10 t/a). Assuming a doubling of the 

Uranium is widely distributed in nature. The Earth s crust contains ca. 4 ppm uranium and seawater 3 ppb uranium. The total inventory in the upper Earth s crust is in the billions of tons, in the oceans 4 10 t. However, only a 

The deposits with over 130 /kg uranium have up to now, as a result of lack of economic interest, hardly been prospected for. The figures given in Table 6.3-1 have been estimated on the basis of general dependencies between concentration and the size of the deposit. 

A comparison of possible demand and reserves shows that the currently known reserves will be consumed in the first half of the twenty-first century However, the probable additional reserves are, assuming increasing demand and depending upon the final level, sufficient for several hundred years. An increase in the price of uranium only has a marginal impact on electricity production costs, see Section 6.1. 

The known and probable deposits ( I. lOS/kg) are suft iciem for over 250 

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The benefits of nuclear power obtainable with the present technology depend on the availability of uranium resources. For example, using the present light water reactor technology, each 1000-megawatt reactor requires a few thousand metric tons of uranium during its 40-year operation. Because... 

Harsh JB Washington State U, Agriculture and Soils, Pullman, WA Physical chemical state and plant availability of uranium in contaminated mine soil U.S. Departmentt of Agriculture Cooperative State Res Service... 

The current availability of uranium is generally specified in terms of availability at a specified price. A 1983 DOE estimate for the United States was 433,400 t of U at 80/kgU, corresponding to the sum of the probable potential (251,500 t), possible potential (98,800 t), and speculative potential (83,100 t) resources at 260/kg U, the corresponding values were 725,700-1-323,800-1-250,700 = 1,300,200 t of U. Uranium prices declined from nearly 110/kg in 1980 to about 40/kg by mid-1984 and remained at about this level during the next 4 years. Needless to say, the current availability in the United States and elsewhere of uranium resources even at the highest prices is smaller by mat r orders of magnitude than the ultimately available resources. A similar remark applies to resources outside of the United States. Thus, the total Western world lesouices (not including the centrally planned economies) were estimated in 1987 to exceed the U.S. resources by factors of about two to four. In 1981, the United States was the world s dominant nraninm producer, with 33.5% of total Western production by 1986, the U.S. share had declined to 14.3%, while Canada had become the dominant producer with 31.6% of total production. In 1986, South African (at 12.5%) and Australian (at 11.2%) production followed U.S. production closely. 

In addition, due to side reactions like the formation of heavier plutonium isotopes 100% of the natural uranium cannot be converted to fissile plutonium isotopes in the breeder technology. However, even the (pessimistic) assumption of a factor of 30 would extend the availability of uranium from 30 to 900 years. 

In this regime of competition orders for the construction of nuclear power plants awarded to the U.S.A., which still maintains an important supremacy over other countries in terms of availability of uranium, advanced technology and enrichment plants, decreased from 85% in 1972 to 40% in 1976. 

The fast reactor has characteristics which make it likely that most of the uranium atoms in natural uranium can be consumed by the process known as breeding. Consequently, if this type of system can be developed a nuclear energy electricity generating system should operate with a much smaller supply of fuel than in the case of natural uranium or slightly enriched uranium thermal fission reactors. The advantages of the fast reactor are therefore bound up with the cost and availability of uranium ores. 

Nuclear fission alone is not the answer. The expected availability of uranium is estimated to produce only 100 TW-h of electricity, and thus if 10 TW of power was obtained from nuclear energy the supply of uranium would be depleted in less than a decade. Moreover, we would need to build a new 1 GW plant every 1.6 days for the next 45 years Lewis and Nocera 2006). This scenario doesn t even address the environmental... 

The high cost of isotope separation has limited, the use of separated isotopes in nuclear reactors to specific cases where substitutes that do not involve separated isotopes are not available. The most important example is that of uranium-235 [15117-96-17, the most abundant naturally occurring... 

This value refers to the natural mixture of uranium isotopes, i.e. it is the atomic weight. Variations are possible because (i) some geological samples have anomalous isotopic compositions, and (ii) commercially available samples may have been depleted in The value for itself is 238.0508. 

Extensive work into the corrosion and oxidation of uranium and its alloys has been undertaken over the past decade but much of this is in the form of Ministry and industrial reports which are not necessarily readily available. The present review concentrates on the work published in the normal scientific and technical press. 

One of the many problems of nuclear power is the availability of fuel uranium-235 reserves are only about 0.7% those of the nonfissile uranium-238, and the separation of the isotopes is costly (Section 17.12). One solution is to synthesize fissile nuclides from other elements. In a breeder reactor, a reactor that is used to create nuclear fuel, the neutrons are not moderated. Their high speeds result in... 

These data clearly indicate that U and Th are not fractionated from each other by amphibole. This is supported by a compilation of all available data, which show that DulD-Yh is within error of unity over a range in Du values from 0.004 to 0.034. Tiepolo et al. (2000a) conclude that amphibole plays no role in fractionation of uranium from thorium in magmas or in the mantle. By the same token we predict Ao Djh-... 

Although the number of actinides is the same as that of the lanthanides, their availability and chemical characteristics have so far largely restricted the study of their ligand substitution mechanisms to dioxouranium(VI), which is the ionic form of uranium most amenable to such studies in solution. In the solid state, the oxo ligands occupy axial sites above and below the U(VI) center, and four (328), five (329, 330), and six (331, 332) oxygen donor atoms have been reported to occupy equatorial positions. From a mechanistic point of view, this variability of the occupancy of the equatorial plane suggests the possibility of both d- and a-activated ligand substitution pro-... 

Exposure Levels in Humans. Although some data on the levels of americium in human tissues exposed to natural background levels (food, water, and air) are available, few measurements have been made on the americium content in human tissues. The principal source of information about occupationally exposed individuals is the U.S. Transuranium and Uranium Registries (USTUR) Tissue Program and database, established to document levels and distribution of uranium and transuranium isotopes in human tissues for occupationally exposed workers (USTUR 1999). Several major database files are available. 

There are methods available to quantify the total mass of americium in environmental samples. Mass spectrometric methods provide total mass measurements of americium isotopes (Dacheux and Aupiais 1997, 1998 Halverson 1984 Harvey et al. 1993) however, these detection methods have not gained the same popularity as is found for the radiochemical detection methods. This may relate to the higher purchase price of a MS system, the increased knowledge required to operate the equipment, and the selection by EPA of a-spectrometry for use in its standard analytical methods. Fluorimetric methods, which are commonly used to determine the total mass of uranium and curium in environmental samples, have limited utility to quantify americium, due to the low quantum yield of fluorescence for americium (Thouvenout et al. 1993). 

In addition it may be helpful to set up, or at least approve, a number of worid specialized manufacturing facilities for example, quality facilities to manufacture the hundred pressure vessels needed each year. Laboratories should be available to expeditiously solve reactor operating problems which may arise worldwide, and to improve reactor performance. And there should be an international program to develop the Fast Reactor which generates some sixty to a hundred times as much energy from a pound of uranium than do our present commercial reactors. 

Technetium then became available in a weighable quantity because of uranium nuclear fission leading to the production of "Tc in nuclear reactors. The total amount of "Tc in the world at the end of 1993 is estimated to be 78 tons, more abundant than rhenium on the earth. 

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. 

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