title: In situ gamma ray measurements of radionuclides at a disused phosphate mine on the West Coast of South Africa.
abstract: High levels of uranium and its radioactive progeny like radium is normally associated with phosphate mining. In Situ gamma ray spectroscopy as a survey tool has been successfully applied to assess radionuclide concentrations in various geographical environments. A transportable and robust gamma ray detection system (GISPI) was therefore employed to determine the concentrations of naturally occurring radionuclides at a disused phosphate mine on the West Coast of South Africa. The concentrations of radium, thorium and potassium were measured and plotted. The measurements showed fairly high concentrations with medians of 320 Bq/kg for (226)Ra, 64 Bq/kg for (232)Th and 390 Bq/kg for (40)K. The highest concentrations were however confined to specific areas of the mine. The effective dose due to gamma irradiation for the various areas of the mine was also estimated and the highest estimated level was 0.45 mSv/y. The article finally draws conclusions as to the origins and impact of the radiation.
authors.affiliation: Faculty of Military Science, Stellenbosch University, South Africa. Electronic address: jab@ma2.sun.ac.za.
authors.forename: Jacques
authors.initials: J
authors.lastname: Bezuidenhout
mesh_terms: D008906:Mining; D010710:Phosphates; D011197:Potassium Radioisotopes / Q000032:analysis*; D011834:Radiation Monitoring; D011883:Radium / Q000032:analysis*; D013019:South Africa; D013051:Spectrometry, Gamma; D013910:Thorium / Q000032:analysis*
chemical_list: D010710:Phosphates; D011197:Potassium Radioisotopes; D013910:Thorium; D011883:Radium
keywords: Gamma ray spectroscopy; In situ measurements; Naturally occurring radionuclides; Phosphate mine; Radium; Uranium