Radiation doses from contaminated food after a nuclear accident

This report presents estimates of radiation doses from contaminated food after a hypothetical accident at a nuclear power plant. The calculations are made from assumptions intended to represent Swedish conditions. The accident scenario is based on a hypothetical core melt in a nuclear power reactor followed by a release to the atmosphere of iodine and caesium corresponding to 0.6% of the Forsmark unit 3 core inventory. The results are expressed in terms of average effective doses from contaminated food to individuals in the critical group living near the power plant, 2 km from the point of release, and living from locally produced foodstuffs. The calculations are made for a winter release and a summer release, and for dry and rainy conditions. Dynamic radioecological models are used, which have been developed from Danish experience with readioactive fallout from nuclear weapons testing and with fallout from the Chernobyl accident. The accidental release is estimated to cause doses in the summer season from 131I of circa 200 mSv to children and circa 30 mSv to adults based on a deposition during dry conditions of 11 MBq 131I m-2. The dosed from 134Cs and 137Cs are estimated at circa 20 mSv to children and adults in case of winter release and circa 160 mSv in case of summer release based on a deposition during dry conditions of 0.5 MBQ 134Cs and 0.4 MBq 137Cs m-2. The main reason for the large difference between the winter and the summer releases is the high sensitivity of cerals to direct contamination on month prior to harvest. In case of precipitation the doses are estimated at twice those for dry conditons. (author) 8 tabs., 16 ills., 13 refs