Determination of natural radionuclides in phosphogypsum samples from phosphoric acid production industry in Senegal

Abstract

In this study, the activity concentration of natural radionuclides (²³⁸U, ²²⁶Ra, ²¹⁰Pb, ²³²Th, and ⁴⁰K) in phosphogypsum were measured using a low-background digital gamma-ray spectrometer equipped with Broad Energy Germanium (BEGe) detector. The mean activity concentrations of ²³⁸U, ²²⁶Ra, ²¹⁰Pb, and ²³²Th were found to be 88.5 ± 19.5 Bq kg⁻¹, 879.6 ± 20.3 Bq kg⁻¹, 755.4 ± 17.1 Bq kg⁻¹, 4.5 ± 0.3 Bq kg⁻¹, and below the detection limit respectively. The estimated radium equivalent activity was found to be higher than the world recommended value of 370 Bq kg⁻¹ but is within the recommended limit of 2220 Bq kg⁻¹ for the use of phosphogypsum in the construction of roads, bridges, and foundations of non-residential buildings. The total annual effective doses received by workers and members of the public were found to be lower than the annual limit of 1 mSv y⁻¹, except for the scenario of a person living in a house built with building material containing phosphogypsum.

Keywords:

• Natural radionuclides
• Gamma-ray spectrometry
• activity concentration
• radiological hazards
• phosphogypsum

Acknowledgments

The authors would like to thank the International Atomic Energy Agency (IAEA) for the fellowship grant and the Metrology of Environmental Radioactivity Laboratory (LMRE, Orsay) of the Nuclear Safety and Radiation Protection Institute (IRSN) to have accepted to welcome the fellowship. They would like also to thank Dr. Ursula Hoeppener-Kramer of the Karlsruhe Institute für Technology (KIT, Karlsruhe) for her contribution to the revised draft paper.

Disclosure statement

No potential conflict of interest was reported by the authors.