TITLE:
Measurement of Natural Radioactivity and Radon Exhalation Rate in Coal Ash Samples from a Thermal Power Plant
AUTHORS:
Aziz Boukhair, Laila Belahbib, Khadija Azkour, Hamid Nebdi, Mohammed Benjelloun, Abdelmjid Nourreddine
KEYWORDS:
Natural Radioactivity, Gamma Spectrometry, LR115, Fly Ash, Bottom Ash, Equivalent Radium, Annual Effective Doses, Exhalation of Radon
JOURNAL NAME:
World Journal of Nuclear Science and Technology,
Vol.6 No.3,
July
11,
2016
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 because of their different uses and especially in
construction materials. In this work, we assess radiation risks due to natural radioactivity in samples of fly and
bottom ashes collected from JLEC
(Jorf Lasfar Energy Company) thermal power plant, and different analyses are performed
through two nuclear techniques such as gamma spectrometry and alpha dosimetry
based on the use of LR115 films detectors. Our analysis shows that 226Ra
activities and 232Th in both ash samples are well above the
permissible activity. The values of the external risk index (Hex)
and internal one (Hin) for these
ashes are below unity, with the exception of 1.28 in fly ash for Hin.
The obtained values for the equivalent radium
Raeq 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.