Radiological impact from atmospheric releases of 226Ra from coal-fired power plants

Abstract

Lignite contains naturally occurring radionuclides arising from the uranium and thorium series and also 40K. Lignite burning is, therefore, one of the sources of technologically enhanced exposure to man from natural radionuclides. Emissions from thermal power stations in gaseous and particulate form contain radioisotopes, such as 226Ra, which are discharged to the environment causing radiation exposures to the population. About 11672 M Bq of 226Ra per year are discharged to the environment from four coal-fired power plants, totalling 3.62 GW electrical energy, at the Valley of Ptolemais, Northern Greece, in which the combustion of 1.1 × 10 10 kg lignite is required to produce an electrical energy of 1 GW year. The collective effective dose equivalent commitment to lung tissue per unit power generated resulting from atmospheric releases of 226Ra was estimated to be 1.1 × 10 −2 manSv (GW year) −1, i.e. more than 15 times higher than that corresponding to a modern-type coal-fired power plant according to the UNSCEAR (1988) data.