ODP Leg 137, borehole fluid chemistry in Hole 504B

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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

FISSION YIELDS OF Srsup9sup 9sup0sup 0

Fission yields were determined from 14-Mev neutrons on U/sup 235/ and U/ sup 238/, thermal neutrons on U/sup 235/, and fission spectrum neutrons on U/sup 235/, U/sup 238/, and Pu/sup 239/. The number of fissions was determined for the Mo/sup 99/ activity. The Sr/sup 90/ was chemically separated and Y/sup 90/ allowed to reach equilibrium. The Y/sup 90/ was separated and counted. (W.D.M.

Sentinel gap basalt reacted in a temperature gradient

Six Basalt prisms were reacted in a controlled temperature gradient hydrothermal circulation system for two months. The prisms are centered at 72, 119, 161, 209, 270, and 310/sup 0/C. Total pressure is 1/3 kbar. All prisms show large weight loss: 5.5% to 14.9%. The matrix micropegmatite and natural nontronitic alteration readily react to clays at all temperatures. The first four prisms are coated with a Ca-smectite while the last two prisms are covered with discrete patches of K rich phengite and alkali feldspar. The clays may act as adsorbers of various ions

Geochemistry studies pertaining to the G-tunnel radionuclide migration field experiment

This report presents the results of geochemical studies of Tunnel Bed tuff that were performed by Los Alamos National Laboratory or done at its direction as part of the Nevada Test Site G-Tunnel Radionuclide Migration Field Experiment. A tuff-treated water was prepared and used in laboratory-scale measurements of radionuclide sorption onto crushed Tunnel Bed tuff, pulverized fracture-fill material, tuff wafers, and a solid tuff core. Modelling studies were undertaken to determine the effects of matrix diffusion and unsaturated tuff on the proposed fracture-flow experiments. The initial results of those studies are presented in this report

Wer kontrolliert die Geschaeftspolitik deutscher Unternehmen?: Empirische Ergebnisse zur Kontrollsituation der 350 groessten deutschen Unternehmen der Jahre 1972, 1979 und 1986 im Vergleich

Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel W 691 (213) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Parameters affecting radionuclide migration in geologic media

Adsorption of several nuclides (Sr, Tc, Cs, Ba, Ce, Eu) on tuff, monzonite, and argillite was studied experimentally. 3 tables. (DLC

Sorption-desorption studies on tuff. II. Continuation of studies with samples from Jackass Flats, Nevada and initial studies with samples from Yucca Mountain, Nevada

Distruibution coefficients were determined by a static (batch) technique for sorption-desorption of radionuclides between tuffs from drill holes UE25a No. 1 and J-13 at the Nevada Test Site and water from well J-13. Measurements were performed under atmospheric and controlled atmosphere conditions. Under atmospheric conditions tuffs high in zeolite minerals had sorption ratios of {similar_to}10{sup 3} to 10{sup 4} ml/g with Sr, Cs, Ba, Ce, Eu, Am, and Pu. For tuffs similar mineralogically to a microgranite the sorption ratios were {similar_to}10{sup 2} to 10{sup 3} ml/g. Values for U and Tc were obtained under controlled atmosphere (< 0.2 ppM 0{sub 2}) conditions. Studies were also begun to measure distribution ratios by a dynamic (column) technique. The ratios obtained for the elements studied, Sr, Cs, and Ba, were similar to, although lower than, those obtained by batch methods