Not only nuclear power plants emit radioactive substances with the exhaust air. Fossil fuels contain various concentrations of natural radioactive substances which are released during combustion. Different firing techniques lead to extremely wide variations in enrichment of the flue dust due to the temperature-dependent volatility. For 1 GWa of electric energy generated the emission of long-lived alpha-radiating substances amounts to about 10 GBq for a hard coal and 1 GBq for a lignite-fired power plant. The effective dose equivalent for various power plants occurring at the most unfavourable point of influence is in the range of 0.1 to 5 microsievert per year.

Primary energy carrier

Max. effective dose in the environment µSv per year

Dose-relevant nuclides

Lignite Hard coal

0.5 to 2
1 to 4

U-238, Th-232 and decay products, in particular Ra-226, Pb-210, Po-210

Natural gas

0.2 to 1

Radon-222 and decay products

Nuclear power

0.1 to 5

Fission and activation products

Radiation exposure by power plants with various primary energy carriers standardized to the generation of 1 GWa electric energy