Title: Radiation background from rock samples and hazards assessment: case of Mounana in Gabon

Authors: Sylvere Yannick Loemba Mouandza; Alain-Brice Moubissi; Patrice Ele Abiama; Thierry Blanchard Ekogo; Maïk Delon Mboumba; Philippe Ondo Meye; Germain Hubert Ben-Bolie

Addresses: Physics Department, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon ' Physics Department, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon ' Physics Department, University of Yaounde I, Yaounde, Cameroon ' Physics Department, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon ' Physics Department, Université des Sciences et Techniques de Masuku (USTM), Franceville, Gabon ' Physics Department, University of Yaounde I, Yaounde, Cameroon ' Physics Department, University of Yaounde I, Yaounde, Cameroon

Abstract: The aim in this present work is to determine the specific activities of ²²⁶Ra, ²³²Th and ⁴⁰K in rock samples collected from Mounana in Gabon, to assess the contribution of natural radioactivity. A p-type high-purity germanium detector has been coupled with a multichannel analyser DSA-1000 to perform measurements and data processing. The energy resolution of the 1332 keV⁶⁰Co line is still found to be 1.8 keV at FWHM, with a relative efficiency of 30%. The specific activities average values of ²²⁶Ra, ²³²Th and ⁴⁰K are 6554±198 Bq/kg, 63±12 Bq/kg and 513±93 Bq/kg, respectively wet weight. To assess the radiological risks due to ²²⁶Ra, ²³²Th and ⁴⁰K, many parameters were estimated. The average value of annual effective dose was 18.95 mSv from the studied area. Rock from Mounana presents a high radioactivity, and we are planning to measure radon in homes to assess the risks of living in Mounana.

Keywords: activity concentration; ²²⁶Ra; ²³²Th; ⁴⁰K; HPGe; background radiation; Mounana; Gabon.

DOI: 10.1504/IJLR.2020.113537

International Journal of Low Radiation, 2020 Vol.11 No.3/4, pp.259 - 272

Received: 29 Jan 2020
Accepted: 13 Jul 2020
Published online: 10 Mar 2021 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article