RADIOLOGICAL HAZARD ASSESSMENT FOR FLY ASH AND ENVIRONMENTAL MATERIALS FROM MORUPULE A COAL-FIRED POWER STATION IN BOTSWANA

This study was undertaken to determine the occupational and public radiation hazardsdueto the usage of fly ash and other environmental materials from Morupule A Coal-Fired Power Station and its environs forconstructionpurposes. Identification and quantification of the natural radionuclides K-40, Th-232 and U-238in water (from the ash ponds), soil, coal and fly ash samples was done through direct gamma ray spectrometry.The averageradium equivalent activity(Ra_eq),representative level index(I_γr),internal hazard index(H_int) and external hazard index(H_ext) values for fly ash samples were 149.038 Bq/kg, 1.031Bq/kg, 0.536Bq/kg and 0.403Bq/kg respectively. For coal samples, the average Ra_eq, I_γr, H_int and H_ext values were 58.662 Bq/kg, 0.407, 0.207 and 0.158 respectively. The average Ra_eq, I_γr, H_int and H_ext values for soil samples were 30.296 Bq/kg, 0.225, 0.100 and 0.082 respectively. Those for water samples were 1.516 Bq/kg, 0.011, 0.005 and 0.004 respectively. The radium equivalent activity, representative level index, external and internal hazard indices for all samples were all within the recommended international values for their safe use as construction material. Results from this study showthat all study samples pose no significant radiological impact to both the workers and public members within Morupule A Coal-Fired Power Station and its surroundings.