The natural radioactivity of coal fired in thermal power plants of Hungary and of coal residues

Natural radioactivity of coal and coal residues have been determined in eight Hungarian coal-fired thermal power plant. In this investigation 61 coal, fly ash and slag samples have been analyzed. 233Th and 238U decay series isotopes and 40K isotopes were analyzed for radioactivity concentration, suing gamma spectrometry methods. The activity concentrations were ranked from the highest value of 426 Bq kg-1 (238U) to the lowest of 10,6 Bq kg-1. The corresponding values for 232Th were 106 Bq kg-1 and 9.8 Bq kg-1, resp. Residues were ranked according to their 226Ra activities. (R.P.) 5 refs.; 2 figs.; 6 tabs