Radioactivity Investigation of Sand from the Northern Region of Tlemcen-Algeria, Using Well-Shape NaI(Tl) Detector

The presence of natural radioactivity in sand and other building materials results in internal and external exposure to the general public. Therefore, it is desirable to determine the concentration of naturally occurring radionuclides. Sand is one of the main components in building construction beside cements, granites and bricks. Thus, this research has been carried out in order to investigate the levels of natural radioactivity and associated radiation hazard in some Algerian sand. The natural radioactivity due to the presence of 226Ra, 232Th and 40K in sand samples used as building materials in Tlemcen province - Algeria was measured by gamma spectrometry using NaI(Tl) scintillation well-shaped detector. In this context, sand samples were collected from four different locations of northern areas of Tlemcen city, Behira seabeach sand, Targa sand, Boukdasen sand, Sidi Bourzin sand. The measured activity in the sand samples ranged from 4.70 to 7.85 Bq.kg-1, 0.80 to 3.00Bq.kg-1 and 22 to 53 Bq.kg-1 for 226Ra, 232Th and 40K, respectively. The concentrations of these natural radionuclides were compared with the reported data for other countries and were found significantly lower than the worldwide average as reported by United Nations Scientific Committee on the Effects of Atomic Radiation (1,2). Radium equivalent activities were calculated (9.25 to 16.39) Bq·kg–1for the analyzed samples to assess radiation hazards arising due to the presence of these radionuclides in the samples. Most of the calculated radium equivalent activities are lower than the limit set in the OECD report at 370Bq.kg–1(3). The measured representative level index values for the investigated samples varied in the range (0.068 to 0.118) Bq.kg-1. External and internal hazard index (Hex,Hin), the specific dose rates indoor (D) and the annual effective dose (DE) due to gamma radiation from building materials was calculated. Keywords. Sand, natural radioactivity, gamma radiation, absorbed dose, radiation exposure, Potassium, Thorium, Uranium, NaI(Tl) Detector, Tlemcen

Natural Radioactivity in Red Clay Brick Manufactured in Tlemcen-Algeria, Using Well-Shape NaI(Tl) Detector

The presence of natural radioactivity in brick and other building materials results in internal and external exposure to the general public. Therefore, it is desirable to determine the concentration of naturally occurring radionuclides. Bricks are one of the main components in building construction beside cements, granites and sand. Thus, this research has been carried out in order to investigate the levels of natural radioactivity and associated radiation hazard in Algerian red brick. The natural radioactivity due to the presence of 226Ra, 232Th and 40K in brick samples used as building materials in Tlemcen province - Algeria was measured by gamma spectrometry using NaI(Tl) scintillation well-shaped detector. In this context, brick samples were collected from two manufactories Tafna and Tounan. The mean values of activity concentrations for 226Ra, 232Th and 40K were found to be in the main value of 15.5Bq.kg-1, 11Bq.kg-1, and 196.5Bq.kg-1, respectively. The concentrations of these natural radionuclides were compared with the reported data for other countries and were found significantly lower than the world wide average (1,2). Radium equivalent activities were calculated (41.3 to 51.4) Bq.kg–1 for the analyzed samples to assess the radiation hazards arising due to the presence of these radionuclides in the samples. The calculated radium equivalent activities are lower than the limit set by the OECD report 370 Bq.kg–1 (3). The measured representative level index values for the investigated samples varied in the range (0.31 to 0.38) Bq.kg1.  External and internal hazard index (Hex,Hin), the specific dose rates in door (D) and the annual effective dose (DE) due to gamma radiation from building materials was calculated. Keywords: Brick, natural radioactivity, gamma radiation, absorbed dose, radiation exposure, Potassium, Thorium, Uranium; NaI(Tl) detector, Tlemcen

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

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