Natural radionuclides near a coal-fired power station

Abstract

A previous assessment of the radiological consequences of the emission of natural radionuclides from coal-fired power stations had indicated that 210Pb was the main contributor to the maximum individual dose. This dose arose from the consumption of foodstuffs particularly cattle liver contaminated by deposited fly ash. Uncertainty surrounded some of the factors used in the assessment, and a limited environmental monitoring programme was recommended to improve it. An experiment has been performed to measure the specific activities of 210Pb and 210Po in livers from cattle that had grazed in a field near Didcot power station. Livers from cattle in the Cotswold region have been measured for comparison. The specific activities of 210Pb and 210Po in soil and grass samples from both areas have also been measured at three-monthly intervals over a year. No statistically significant increases were observed in the 210Pb and 210Po levels in liver, soil or grass samples which could be attributed to the operation of the power station. Transfer coefficients for 210Pb from forage to liver were about two orders of magnitude less than that used in the original assessment, and the transfer coefficients for 210Po about a factor a two less.