engleski

Radiological Characterization of the Coal Ash and Slag from Kastel Gomilica, Croatia

The objective of this study was radiological characterization of slag and ash produced in a thermo electric unit of the former "Adriavinil" chemical factory as a by-product of coal combustion and deposited in the Kastel Gomilica region, Croatia. The waste material was deposited in the "old" regulated and the "new" unregulated part of the depot. 33 samples were analyzed to obtain a preliminary data on the present state of the new unregulated part of the depot. Activities of the selected radionuclides (K-40, Th-232, U-235 and Ra-226) were measured using gamma-spectrometry method. U-238 activity was calculated from the assumed natural U-235/U-238 activity ratio. It is found that there is a dependence of the activities of the selected radionuclides on the activities of the coal used for energy production in the power unit. The content of Th-232, Ra-226 and U-238 in slag and ash increased several times during the combustion process. Investigated slag and ash showed a significant variability in their activities of selected radionuclides due to a different origin of coal used in the thermoelectric unit of the factory. The waste material was characterized by high activity of naturally occurring U-238, U-235 and Ra-226. Ra-226 and U-238 activities were up to 50 times higher than their average activities characteristic for surrounding soils developed on flysch sediments. K-40 and Th-232 showed no elevation compared to soil activities. Mineralogical analysis has been made as well.

slag; ash; radionuclide; coal; gamma-spectrometry; Croatia

nije evidentirano