16 Radioactivity, Geology, and Human Health (Posters)
Sunday, 25 August 2013
12:00 PM - 11:55 PM
Virginia Ballroom
FRACTIONATION OF URANIUM ISOTOPES IN WATER FROM SAN MARCOS DAM IN CHIHUAHUA, MEXICO
Paper number: 16-3
Program: Sessions
Time: 12:00 PM – 11:55 PM
Authors
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Maria Elena Montero-CabreraInternational Center For Advance Material, Chihuahua, N/A
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Marusia Renteria-VillalobosAutonomous University of Chihuahua, Chihuahua, N/A
Abstract
The objective of this work was to assess the fractionation and distribution of isotopic uranium contained in suspended matter and dissolved fraction in water of the San Marcos Dam located in Chihuahua, Mexico Uranium was measured in three points along the San Marcos dam: water input, midpoint, and near to dam wall. This last point was also sampled in two depths. Every water sample was filtered to obtain the suspended matter with particle size of >20µm. Isotopic uranium was determined by liquid scintillation. The distribution coefficient kd ranged between 1.7 ·102 to 1·103 L g-1. In dissolved fraction, high concentrations of 234U were found, where the activity ratio (AR, 238U/234U) ranged from 2.1 to 3.5. In average, uranium contents tend to be concentrated in suspended matter, with AR near to unit. Uranium concentration varies along the dam, being the highest 238U concentration at water input point. The results showed a possible lixiviation of uranium from geological substrate and, also, an important fractionation of uranium isotopes suggesting that those are non-homogeneously distributed along San Marcos dam.