On the assessment of the radiological burden caused by nuclear power stations

The exposure dose in the environment of a nuclear power station caused by the emission of radioactive noble gases through the exhaust air stack as a result of plant operation is determined by the activity and the radiological effectiveness of the mixture released and by the meteorological distribution conditions. In principle, these parameters are independent of each other and may be subject to marked seasonal variation. In the absence of detailed measurements of these parameters it has been necessary for purposes of environmental protection so far to postulate a large number of conservative assumptions in calculating the radiological effects. However, the state of the art now permits both the emission and the distribution conditions to be measured at any point in time in such a way that the true exposure dose can be assessed with an accuracy greater by several orders of magnitude. In this way, the dominating aspects of the protection of the public can be harmonized with those of economical power plant operation on a realistic basis much more efficiently than before, and the duties with respect to information of the public and the execution of exposure studies can be discharged much more accurately. Moreover, important aids have now become available in deciding about protection and emergency measures if activities were to be released as a result of some incident. (orig.)