30 research outputs found
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Radionuclide transport and retardation in tuff
Batch measurements provide an understanding of which experimental variables are important. For example, sorption ratios vary little with particle size (and surface area); however, groundwater composition and rock composition are quite important. A general correlation has been identified between mineralogy (major phases) and degree of sorption for strontium, cesium, and barium. Although these are approximate, a more detailed analysis may be possible as more samples are studied and the data base increased. Data from crushed tuff columns indicate that, except in simple cases where sorption coefficients are relatively low, and ion-exchange equilibria not only exist but are the dominant mechanism for removal of radioisotopes from solution, the simple relation between the sorption ratio R/sub d/ (or K/sub d/) and the relative velocity of radionuclides with respect to groundwater velocity may be insufficient to permit accurate modeling of the retardation of radionuclides. Additional work on whole core columns and larger blocks of intact material is required to better understand radionuclide sorption and transport through rock
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Sorption--desorption studies on argillite. I. Initial studies of strontium, technetium, cesium, barium, cerium, and europium
Distribution ratios were determined for sorption--desorption of radioactive tracers between Eleana argillite available from the Nevada Test Site and a water prepared to be representative of the natural groundwater composition. The measurements were preformed at 22{sup 0}C and 70{sup 0}C under atmospheric oxygen conditions. The order of increasing distribution coefficient by element at both temperatures is Tc(VII), Sr, Cs, Ba, Eu, and Ce. The effects of surface area and mineralogy were also investigated. 34 figures, 26 tables
Symmetry of neutron induced U²³⁵ fission at individual resonances : final report /
Prepared for U.S. Atomic Energy Commission."Plowshare Program"--Cover."Issued: April 17, 1963"--Cover ; "February 1963"--Title page."Project 7.03.""PNE-114F.""Project Gnome."Includes bibliographical references (page 8).Mode of access: Internet
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Current status of laboratory sorption studies
LASL batch sorption methodology was used to obtain data on granite, argillite, and tuff samples. Effects of solution-to-solid ratio, isotope concentration, atmosphere, and mineralogy were investigated for the elements strontium, cesium, barium, cerium, europium, technetium, uranium, plutonium, and americium. A circulating system was used in making sorption measurements for comparison with conventional batch techniques. The mineralogy of several tuff, granite, and argillite samples was studied and compared with sorption ratios. A significant correlation between sorption of strontium, cesium, and barium and major rock phases was observed
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Sorption--desorption studies on tuff. I. Initial studies with samples from the J-13 drill site, Jackass Flats, Nevada
Distribution coefficients were determined for sorption--desorption of radionuclides between each of three different types of tuff from drill hole J-13 at the Nevada Test Site and water from that well. The measurements were performed under atmospheric conditions at 22{sup 0}C and 70{sup 0}C. Sorption ratios vary greatly with lithologic variety of tuff. A tuff high in zeolite minerals has high sorption ratios (in decreasing order) for Eu, Ba, Cs, and Am and intermediate ratios for Sr and Pu. A tuff high in glass shows very high ratios for Ba, Sr, and Cs, intermediate values for Am and Pu, and low values for Ce and Eu. A devitrified tuff similar mineralogically to a microgranite exhibits intermediate values for Ba, Cs, Am, and Pu and low values for Eu, Ce, and Sr. Values for Ru are low, and those for Mo, Sb, and I are very low or zero for the three types. 34 figures, 32 tables