[en] San Rafael Mining and Milling Complex is located in Mendoza province, in San Rafael Department, 38 km West from San Rafael city and 240 km South from Mendoza city, capital of the province. Activities related with yellow cake production were performed from 1979 to 1999. Nowadays the mine and the plant are in stand by. At the moment technical, economic and environmental studies are being done in order to restart the activities. Different kind of residues are accumulated in the site: a) Tailing; b) Sludges; c) Low grade ores; e) Waste rock; f) Mine water; g) Solid residues (RS). In this paper methodology to treat mine water and solid residues (RS) will be informed. a) Mine water: 800.000 m3 of mine water are accumulated in different open pit. Uranium, radium and arsenic are the main ions to take into account to treat the water. Several laboratory and pilot test have been performed in order to define the treatment of the water, according with the regulatory requirement. A methodology using anion exchange resin to fix uranium and precipitation using barium chloride and iron sulfate to separate radium and arsenic has been developed. b) Solid residues (RS): these residues (precipitates) have been produced by neutralization of effluents in a nuclear purification process (TBP process). They are accumulated in drums. These residues come from Cordoba plant, a factory which produces UO2 powder. The total content of uranium in the precipitate is 14.249 kg with an average uranium concentration of 1,33%. A methodology using sulfuric acid dissolution of the precipitates and anion exchange resin to recovery the uranium has been developed. (author)
[es]
El Complejo Minero Fabril San Rafael (CMFSR) se encuentra ubicado en la provincia de Mendoza, Departamento de San Rafael a 38 km al oeste de la ciudad de San Rafael y a 240 km al sur de la ciudad de Mendoza, capital de la provincia. En el mismo se produjo concentrado de uranio durante el periodo 1979-1999. A partir de 1995 se detuvo la explotacion minera, encontrandose en la actualidad sus instalaciones en stand-by. A partir del anio 1999 se comenzaron a realizar estudios tecnicos, economicos y ambientales orientados a reiniciar las actividades productivas Por tal motivo, como parte inicial del proyecto, se definio la necesidad de comenzar la gestion de los residuos que quedaron acumulados en la etapa operativa, que son: a) Colas de mineral; b) Lodos precipitados; c) Minerales marginales; d) Escombreras de roca esteril; e) Agua de cantera; f) residuos solidos (RS). En este trabajo, en particular, se describira la metodologia de tratamiento de los dos ultimos mencionados. a) Agua de cantera: en la actualidad, la cantidad de agua acumulada en las distintas canteras del CMFSR es de 800.000 m3, y proviene del agua de lluvia y agua subterranea que ingresa a las zonas donde se llevan a cabo las explotaciones mineras. El agua de cantera presenta contenidos de uranio, radio y arsenico superiores a los del background de la zona, debido al contacto del agua con la roca mineralizada. Con el objeto de gestionar el agua de cantera, cumpliendo con los requisitos regulatorios vigentes, se han llevado a cabo estudios de tratamiento para proceder a la descontaminacion de la misma. Se hicieron estudios utilizando resinas de intercambio ionico anionicas (Amberlite IR 400) para captacion de uranio y tambien se realizaron ensayos para disminuir la concentracion de arsenico y radio-226 en agua de la cantera, por precipitacion fraccionada utilizando sulfato ferrico, cal y cloruro de bario. b) Residuos solidos (RS): estos residuos provienen de la neutralizacion de efluentes del proceso de purificacion nuclear que se realiza en la planta de produccion de dioxido de uranio (Cordoba). Existen 5.223 tambores conteniendo precipitados humedos. El total de uranio en los tambores es 14.249 kg, con un tenor medio de uranio de 1,33%. El objetivo del tratamiento es gestionar estos precipitados y recuperar el uranio contenido en los mismos. (autor)Journal
Revista de la Comision Nacional de Energia Atomica; ISSN 1666-1036; 
; v. 6(23/24); p. 15-24
; v. 6(23/24); p. 15-24
[en] The cross section for the 3He(e,e(prime)d)p reaction has been measured as a function of the missing momentum pm in (q,omega)-constant kinematics at beam energies of 370 and 576 MeV for values of the three-momentum transfer q of 412, 504 and 604 MeV/c. The L(+ TT), T and LT structure functions have been separated for q=412 and 504 MeV/c. The data are compared to three-body Faddeev calculations, including meson-exchange currents (MEC), and to calculations based on a covariant diagrammatic expansion. The influence of final-state interactions and meson-exchange currents is discussed. The pm-dependence of the data is reasonably well described by all calculations. However, the most advanced Faddeev calculations, which employ the AV18 nucleon-nucleon interaction and include MEC, overestimate the measured cross sections, especially the longitudinal part, and at the larger values of q. The diagrammatic approach gives a fair description of the cross section, but under (over)estimates the longitudinal (transverse) structure function
Journal
Nuclear Physics. A; ISSN 0375-9474; ; v. 706(3-4); p. 403-417
; v. 706(3-4); p. 403-417
[en] The reaction 16O(e,e'pp) has been studied at a transferred four-momentum (ω,|q|)=(210MeV,300MeV/c) . Evidence has been obtained for direct knockout of proton pairs from the 1p shell. The excitation-energy spectrum of the residual nucleus and the missing-momentum densities indicate that knockout of a 1S0 pair dominates the reaction, while there is also a noticeable contribution from knockout of 3P pairs. copyright 1997 The American Physical Society
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[en] We report measurements of cross sections for the reaction 1H(e,e(prime) K+)Y, for both the Λ and Σ0 hyperon states, at an invariant mass of W = 1.84 GeV and four-momentum transfers 0.5 < Q2 < 2 (GeV/c)2. Data were taken for three values of virtual photon polarization ε, allowing the decomposition of the cross sections into longitudinal and transverse components. The Λ data are a revised analysis of prior work, whereas the Σ0 results have not been previously reported
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[en] The deuteron elastic structure function A(Q2) has been extracted in the range 0.7 < or = Q2 < or = 6.0 (GeV/c)2 from cross section measurements of elastic electron-deuteron scattering in coincidence using the Hall A Facility of Jefferson Laboratory. The data are compared to theoretical models, based on the impulse approximation with the inclusion of meson-exchange currents, and to predictions of quark dimensional scaling and perturbative quantum chromodynamics
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