Public exposure to radiation resulting from the generation of electricity by nuclear power plants is just a fraction of that from coal-powered plants, according to a report from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR).
UNSCEAR yesterday released the results of a comparative study it has conducted of exposures from generating technologies based on nuclear power, coal, natural gas, oil, biofuels, geothermal, wind and solar.
The committee said that while exposure levels are very low, the coal cycle contributed more than half of the total radiation dose to the global population from electricity generation. The nuclear fuel cycle, it said, contributed less than one-fifth of this. The collective dose for coal generating technologies is 670-1400 man Sieverts, depending on the age of the power plant, while that of nuclear is 130 man Sv. This is followed by geothermal at 5-160 man SV, natural gas at 55 man Sv and oil at 0.03 man Sv.
UNSCEAR also evaluated radiation exposure per unit of electricity generated, using 2010 as a reference year for comparison. The committee concluded that the values for coal and nuclear are about the same in the short term: 0.7-1.4 man Sv per GWe for coal and 0.43 man Sv/GWe for nuclear.
It noted over a period of hundreds of years, "an accumulation of very small doses from long-lived radionuclides result in larger collective doses from the nuclear fuel cycle". However, the total collective dose (to both the public and workers) per unit of electricity generated by the coal cycle was larger than that generated by the nuclear fuel cycle, "even when considering the long-lived globally-circulating radionuclides integrated out to 500 years".