Radiological assessment of Coltant mining in Nigeria

Abstract

Coltant has global demand for variety of application due to its qualities of being good heat conductor, corrosion resistant. The aim of this study was to assess radioactivity level emanating from coltant shipments from Nigeria, due to several recorded cases of delays/denials and impoundment from transit or importing countries, using RDS-31S/R Multi-purpose survey meter, Radionuclides Identifinder and Sodium Iodide detector. The dose rate measurement from the coltant samples ranges from (0.23±04 and 8.44±03) ???/ℎ? which was above maximum dose rate of 1 ???/ℎ? at 1m from the package surfaces. Also, specific activity concentration of ²²⁶Ra, ²³²Th and 40K found to be (335±195 - 15,786±9,164) Bqkg-1, (152±18 - 15,201±1,738) Bqkg-1and (16±10 - 142±21) Bqkg-1, respectively. The evaluated GDR was with a mean value of 7959 nGy/hr higher than world mean of 59 nGy/hr. The outdoor and indoor AEDR estimated were 9.76 mSv/yr and 39.05 mSv/yr respectively higher than world mean of 420 mSv/yr; the estimated ELCR was 3333 higher than world mean value of 0.29 × 10^-3 as reported in UNSCEAR 2000. The radiological risk assessment from this investigation reveals workers and public in such mining areas and other biota will definitely be overexposed leading to radiation health effects over long term. It is recommended that there should be effective regulatory control of mines and mining Coltant products which often contains fissile material, ore and radioactive substances.

Keywords: Coltant, Mines products, Radioactivity level, Shipment and Transportation Packages