Uranium radium and

Todd, J.F., Elsinger, R.J., and Moore, W.S. (1988) The distributions of uranium, radium, and thorium isotopes in two anoxic fjords Framvaren Fjord (Norway) and Saanich Inlet (British Columbia). Mar. Chem. 23, 393—415. 

Phair, G., and H. Levin Notes on the differential leading of uranium, radium and lead from pitchblende in H2S04 solutions. Econ. Geol. 48, 358 (1953). 

Uranium, Radium and Vanadium Ores Effluent Guidelines and Standards 40 CFR 440, Subpart C EPA 1982b... 

Be, with its 1.5 Ma half-life, adds a longer-lived subduction tracer to the arsenal, one that will decay away in the mantle on a time frame of several million years. The data for the SVZ of S Chile (Figure 6(a)) illustrate the power of the combined approach. The very well correlated U-Th, Ra-Th, and Be/ Be data indicate that uranium, radium, and Be, but not thorium, were transported from slab to mantle to produce the nearly horizontal arrays on the disequilibria diagrams (right panel) and the strong correlations between Be addition and uranium and radium excesses (left panel). Taken at face value, these results suggest that a slab/sediment-derived fluid was added to the... 

The Straz deposit in the Hamr District of the Czech Republic provides a good example of this problem (Slezak, 1997). Starting in 1968, more than 4 Mt of sulfuric acid, 3 X 10 t of nitric acid, and 1.2 X 10 t of ammonia were injected into the subsurface to mine uranium ore. Now, —266 Mm in the North Bohemian Cretaceous Cenomanian and Turonian aquifers are contaminated with uranium, radium, and manganese and other solutes. The contaminated area is more than 24 km and threatens the watershed of the Plucnice River. 

Menzel, R.G., Uranium, Radium and Thorium content in phosphate rocks and their possible radiation hazard. J. Agric. Food Chem., 16 (1968) 231-234. 

Asikainen, M. and Kahlos, H., 1979. Anomalously high concentrations of uranium, radium and radon in water from drilled wells in the Helsinki region. Geochim. Cosmochim. Acta, 43 1681-1686. 

Radon is a naturally occurring colorless, odorless, tasteless radioactive gas that is formed from the normal radioactive decay of uranium. Uranium is present in small amounts in most rocks and soil. It slowly breaks down to other products such as radium, which breaks down to radon. Some of the radon moves to the soil surface and enters the air, while some remains below the soil surface and enters the groundwater (water that flows and collects underground). Uranium has been around since the earth was formed and has a very long half-life (4.5 billion years), which is the amount of time required for one-half of uranium to break down. Uranium, radium, and thus radon, will continue to exist indefinitely at about the same levels as they do now. 

Dehierne started his work with a few hundreds kilograms of uranium ore extracting the active principle from it. After, he had extracted uranium, radium, and polonium he was left with a small amount of a substance whose activity was much higher than the activity of uranium (approximately, by a factor of 100 000). At first, Dehierne assumed that this highly radioactive substance was similar to titanium in its chemical properties. Then he corrected himself and suggested a similarity with thorium. Later, in spring of 1899 he announced the discovery of a new element and called it actinium (from the Greek for radiation). 

Water can also become contaminated with radioactive impurities, especially in areas rich in uranium deposits. These include uranium, radium, and radon, all of which come primarily from natural sources. Ingestion of these contaminants increases cancer risk. 

JuRAiN, G. Contribution to the geochemical knowledge of the families of uranium-radium and of thorium in the southern Vosges — Application of some results to prospecting of deposits of uranium. Sci de la Terre Mem., no. 1, 349 p. (1962). 

Originally, radium was obtained from the rich pitchblende ore found in Joachimsthal, Bohemia. The carnotite sands of Colorado furnish some radium, but richer ores are found in the Republic of Zaire and the Great Lake region of Canada. Radium is present in all uranium minerals, and could be extracted, if desired, from the extensive wastes of uranium processing. Large uranium deposits are located in Ontario, New Mexico, Utah, Australia, and elsewhere. 

Although the nucleus of the uranium atom is relatively stable, it is radioactive, and will remain that way for many years. The half-life of U-238 is over 4.5 billion years the half-life of U-235 is over 700 million years. (Half-life refers to the amount of time it takes for one half of the radioactive material to undergo radioactive decay, turning into a more stable atom.) Because of uranium radiation, and to a lesser extent other radioactive elements such as radium and radon, uranium mineral deposits emit a finite quantity of radiation that require precautions to protect workers at the mining site. Gamma radiation is the... 

In 1896, the French scientist Fienri Becquerel happened to store a sample of uranium oxide in a drawer that contained some photographic plates (Fig. 17.2). He was astonished to find that the uranium compound darkened the plates even though they were covered with an opaque material. Becquerel realized that the uranium compound must give off some kind of radiation. Marie Sklodowska Curie (Fig. 17.3), a young Polish doctoral student, showed that the radiation, which she called radioactivity, was emitted by uranium regardless of the compound in which it was found. She concluded that the source must be the uranium atoms themselves. Together with her husband, Pierre, she went on to show that thorium, radium, and polonium are also radioactive. 

Cochran JK, Masque P (2003) Short-lived U/Th-series radionuclides in the ocean tracers for scavenging rates, export fluxes and particle dynamics. Rev Mineral Geochem 52 461-492 Cohen AS, O Nions RK (1991) Precise determination of femtogram quantities of radium by thermal ionization mass spectrometry. Anal Chem 63 2705-2708 Cohen AS, Belshaw NS, O Nions RK (1992) High precision uranium, thorium, and radium isotope ratio measurements by high dynamic range thermal ionization mass spectrometry. Inti J Mass Spectrom Ion Processes 116 71-81... 

Moore DG (1967) Amazon and Mississippi River concentrations of uranium, thorium, and radium isotopes. Earth Planet Sci Lett 2 231-234... 

McKee BA, DeMaster DJ, Nittrouer CA (1986b) The use of " Th/ U disequilibrium to examine the fate of particle-reactive species on the Yangtze continental. Shelf. Earth Planet Sci Lett 68 431-442 McKee BA, DeMaster DJ, Nittrouer CA (1987) Uranium geochemistry on the Amazon shelf evidence for uranium release from bottom sediments. Geochim Cosmochim Acta 51 2779-2786 Miller RJ, Kraemer, TF, McPherson BF (1990) Radium and radon in Charlotte Harbor estuaiy, Florida. Estuar Coastal Shelf Sci 31 439-457... 

Radon gas is the result of the radioactive decay of radium-226, an element that can be found in varying concentrations throughout many soils and bedrock. Figure 31.1 shows the series of elements that begins with uranium-238, and, after undergoing a series of radioactive decays, leads eventually to lead-210. At the time radium decays to become radon gas, energy is released.9 Of all the elements... 

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