Radioactivity of residues from waste incineration facilities in Finland

Abstract

Waste incineration in Europe has been increasing in the past few decades as there is a need to reduce the burden on landfills and their associated environmental concerns. While incineration reduces the volume of the waste, the volume of slag and ash is still substantial. To find out potential radiation risks that incineration residues could set to workers or the public, the levels of radioactive elements in these residues were investigated from nine waste incineration plants in Finland. Natural and artificial radionuclides were detected in the residues, but in general the activity concentrations were low. This study shows that the level of Cs-137 in the fly ash from municipal waste incineration follows the pattern of 1986 fallout zones in Finland, although the levels are significantly lower than in ash from bioenergy production from the same areas. Am-241 was also detected in many samples, although the activity concentrations were very low. Based on the findings in this study, the typical ash and slag residues from municipal waste incineration do not need radiation protection measures for workers or the public even in regions that received up to 80 kBq m^-2of Cs-137 fallout in 1986. The further use of these residues need not be restricted due to radioactivity. Hazardous waste incineration residues and other special cases need to be considered separately, depending on the original waste composition.

Keywords: bottom ash; bottom slag; fly ash; municipal solid waste; radioactivity; waste incineration.