French practice in quantitative forecasting of potential atmospheric pollution resulting from nuclear activities

Since 1945, development of the nuclear industry in France has been accompanied by specially undertaken studies of atmospheric pollution prevention and control which were stepped up substantially following the accident at the No 1 reactor at WINDSCALE in Great Britain, October 1957. Initially work focused on the rapid development of practical graphical aids (LE QUINIO) based directly on full-scale tests with tracers at various French sites and having no mathematical justification. Later, from about 1970, and in part to meet the new demands and radiological safety problems associated with the nuclear tests in the Pacific, efforts were made, based on data from the various French and other 'tracer' experiments both opportunistic and pre-planned, to develop a model (DOURY) sufficiently simple to be practical and efficient in use but still able to handle as many genuine problems as possible, principally by avoiding the relatively narrow constraints of the earlier graphical aids. The two approaches, the former still used in its original form in the nuclear sector of Electricite de France and the latter now being introduced in the Support Technique de la Puissance Publique, are presented and discussed. They are then compared in terms of efficiency and complementarity, and also in respect of numerical results, particularly in the light of corresponding results provided by the methods (PASQUILL-GIFFORD) used in other countries