Dose distributions in Western Europe following Chernobyl

The author describes the different circumstances that, in a reactor accident, lead to varying compositions of radionuclides being released, depending on the operational state and exact sequence of events. The range of radionuclides released is so variable that it is not possible to know in advance either what will be released or what exposure pathways will be important. This is illustrated with comparison of magnitudes of release and radiological consequences of the 1957 Windscale accident, Three Mile Island in 1979 and Chernobyl in 1986. The atmospheric dispersion of material from the Chernobyl accident is traced and the differences in deposition that occurred across Scandinavia and Europe discussed. This leads to estimates of ranges of doses in each country and of contributions from each exposure pathway. Comments are also made on the radiological basis for taking action to protect members of the public and the difficulties encountered in practice when applying the criteria. (author)