Measurement of Natural Radioactivity in Cement of Tlemcen -Algeria by Using Well-Shape NaI(Tl) Detector

Abstract

The aim of this study was to characterize the concentrations of 40K, 226Ra and 232Th in the cement samples manufactured in Tlemcen (Algeria) using a high-efficiency gamma-ray spectrometer. Measurements of radioactivity in the environment are of great importance to monitor and control the levels of radiation to which man is exposed directly or indirectly. The environment around people is radioactive due to ionising radiation from the sky, the Earth's crust, and various atoms existing in the water, food, building materials and metals. Indoor exposure arises from the soils on which the building stands and the building materials used during construction. This is because all building materials contain certain levels of natural radionuclides 238U, 232Th, and 40K. The building materials like bricks, concrete, sand, cement etc. are earth based, containing uranium and thorium in varying amounts which are the biggest inescapable sources of natural ionizing radiation for human exposure. The objectives of this study were to determine the level of natural radioactivity and associated radiological hazard caused by natural radioactivity in local cement factory of Beni-Saf (province Tlemcen) in Algeria has been measured using NaI (Tl) 2x2 well detector (Canberra Inc.). These samples were analyzed using gamma-ray spectrometry technique. The spectra of samples were collected and measured using a multichannel analyzer (MCA) connected with measurement system for this purpose. Activity concentrations of 226Ra (238U series), 232Th and 40K were found in the range of 1.0-4.2 Bq.kg-1, 4.85-7.7 Bq.kg-1and 115.3Bq.kg-1, respectively. The average values of activity concentrations obtained for 226Ra, 232Th and 40K in different samples of cement are lower than the corresponding global values reported in UNSCEAR publications. The results obtained in this study show no significant radiological hazard when Beni-Saf cement is used for construction of buildings.Keywords: Activity Concentration, Cement Samples, Gamma-Ray Spectrometry Technique.