Caracterización de radionucleidos presentes en el suelo de la provincia de Chimborazo.

Abstract

The research objective was the characterization of gamma-emitting radionuclides present in the ground of Chimborazo province, radionuclides were identified in the geologic units of the provincial surface. In addition, specific activities and external exposure by natural terrestrial radiation. This research covered the provincial surface of 6569 km2, Chimborazo province has 21 geologic units and a latitude variation from 300 MASL to 6310 MASL. A hundred twenty soil samples were taken considering the viability of the province through a stratified random sample. Surface sampling was conducted to a depth of 5 centimeters. A pre-treatment was carried out on the samples in the Unitary Operations Lab of the School of Chemical Engineering. The analysis of the samples is carried out using a gamma spectrum of hyperpure Ge (HPGe) of the Subsecretariat Lab of Control and nuclear applications (SCAN) of the Ministry of Electricity and Renewable Energy (MEER). Three main radionuclides were found in the ground 226Ra, 232Th, and 40K and its descendants. The results at a provincial level are the absorbed dose rate due to gamma emitters 33,55 ± 0,9567 nGy/h and the and the total annual gamma effective dose rate 0,2716 ± 7,7x10-3 mSv/year with approximately 43,14% and 43,42% below the worldwide average respectively, thus the Chimborazo province does not exceed the global average level. However, there are points that exceed the average which are in the following geological units: Guasuntos unit (40K exceeds in 6,550%) and Peltetec unit (232Th exceeds in 25,17% and 40K exceeds in 29,35%) this radioactivity is attributed to blackboards and basalt rocks. It is recommended carried out more studies in these zones which present the highest activity.