NATURALLY OCCURRING RADIOACTIVE MATERIALS (NORM) IN ASHES FROM A FUEL-OIL POWER PLANT IN CIENFUEGOS, CUBA, AND THE ASSOCIATED RADIATION HAZARDS

摘要

The radioactivity of NORM was measured in ashes collected from a fuel-oil power plant in Cienfuegos, Cuba, using an HPGe gamma-ray spectrometer. The ~(226)Ra, ~(210)Pb, ~(40)K, ~(232)Th and ~(238)U activity concentrations reached 240, 77, 59, 70 and 15 Bq kg~(-1), respectively. The potential radiological hazard of these residuals was assessed. The radium equivalent activities of the samples varied from 54 to 345 Bq kg~(-1). The gamma index was calculated to be lower than that of the reference values, and the gamma absorbed dose rate was higher than the average reported for the earth's crust; however, the assessed annual effective dose was slightly lower than the annual effective dose limit for public, i.e. 1 mSv. Therefore, these bottom ashes were not dramatically enriched with radionuclides and may be used as an additive for building materials without restrictions from a radiological protection point of view.