Investigation of the uranium content in sedimentand soil samples from the Santos and Sao Vicente estuary region, sp

Abstract

In this work the uranium (U) content in sediment and soil samples collected near the Santos and São Vicente estuary was determined using the fission track registration technique (SSNTD). The sediment and soil samples after oven-dried and pulverized were prepared in the solution form. Around 10 µL of this solution was deposited on the plastic detector (PCLIGHT) and irradiated at the IEA-R1 (3.5 MW) nuclear reactor. After the irradiation and chemical etching of the plastic foils, the fission tracks were counted with a system consisting of an optical microscope together with a video camera and a PC computer. The U content in the analyzed samples ranged from 3.12 ± 0.55 to 18.3 ± 1.2 ppm for sediments and from 3.21 ± 0.63 to 11.5 ± 1.1 ppm for soils. These resultas were compared to other values reported in the literature for sediments and soils collected in environments similar to the ones studied in this work The average values for the U content obtained in this work are significatively higher (above twice) than the world mean and are in reazonable agreement with results found by other authors for sediments and soils from regions considered as polluted or with a high level of radioactivity.