Hodnocení radioaktivity důlní hlušiny v lokalitách s těžbou uhlí

Abstract

Objective of the presented theses was to assess radioactivity contamination of tailings in coal mining sites and to evaluate the suitability of the material for construction purposes. Radioactivity assessment of coal tailings was made for carboniferous rocks from the ostrava strata of Ostrava-Karvina coal field. Specific mass radioactivity activity 40K, 226Ra a 232Th of rock samples was determined for six samples using gamma spectrometer including estimation of measurements uncertainty. Based on this results it was calculated the value of specific mass activity index I, which is an indicator of natural radioactivity of rocks according to the state regulation act No. 422/2016. The specific mass radioactivity was determined for he burnt up sample representing the burned out waste material. From the analysis it was concluded that the value of the index I for the original samples was in the range of 1,09-1,40 and for the burnt out samples around 0,64. Lower activity of burned samples compared with the original ones was find due to the release of isotopes of Rn of uranium and thorium decay series during heating. Considering the provisions of the above mentioned regulation act, the waste represented by the original samples is possible to use in structures without residence of persons and the burned out waste material also for building with residence of persons.