Application of the alpha spectrometry for the study of core sediment extracted in the San Marcos dam in Chihuahua

The determination of the specific activities of 210Po and isotopic uranium by alpha spectrometry was performed in a sediment core from San Marcos Dam. The objective of this work was to analyze the vertical distribution of isotopic uranium and 210Po and the behavior of these radionuclides along sediment core collected from the San Marcos Dam. Sample was divided into 11 sections, in which 210Po and isotopic uranium were determined using liquid-liquid extraction with tributyl phosphate. Furthermore, it was made a comparison between the tributyl phosphate technique and the technique of extraction chromatography using UTEVA resins for uranium. The results of specific activities for 210Po show a trend to decrease along the core, whereas the uranium isotopic does not show a pointed trend. The results of isotopic ratios between the 234U and 238U show that they are close to secular equilibrium in each of the core sections. The comparison between the two uranium extraction techniques indicates that the chemical yield is better using the UTEVA technique than tributyl phosphate extraction. (Author)