Measurement of Natural Radioactivity and Radon Exhalation Rate in Coal Ash Samples from a Thermal Power Plant

Abstract

Coal is the main energy source for electricity generation in the world. In Morocco, 37% of electricity generation comes from combustion coal in thermal power plants. This combustion process generates large amounts of fly and bottom ashes. In recent years, these ashes became a great topic of interest be cause of their different uses and especially in construction ma terials. In this work, we a ssess radiation risks due to natural radioactivity in samples of fly and bottom ashes collect ed f rom JLEC (Jorf Lasfar Energy Company) thermal power plant, and different analyses are pe rformed through two nuclear techniques such as gamma spectrometry and alpha dosimetry based on the use of LR115 films detectors. Our analysis shows that 226 Ra activities and 232 Th in both ash samples are well above the permissible activity. The values of the external risk index (H ex ) and internal o ne (H in ) for these ashes are below unity, with the exception of 1.2 8 in fly ash for H in . The obtained values for the equivalent radium Ra eq and annual effective doses Ė in fly and bottom ashes are 324 Bq/kg and 210 Bq/kg, and 0.18 mSv/y and 0.11 mSv/y, respectively. The surface radon exhalation rates for the samples of fly and bottom ashes are 276 mBq ⋅ m - 2 ⋅ h - 1 and 381 mBq ⋅ m - 2 ⋅ h - 1 , respectively. Based on these results, we have shown that fly ash and bottom one from thermal power plant JLEC didn’t have, in any case, a health risk to the public so it can be effectively used in various construction activities.