The French emergency plans in the event of nuclear accidents.

Abstract

The purpose of the French Health Protection Policy in the event of a nuclear accident is to establish emergency plans particular to each site (EPP) applicable outside the plant. The methodology includes several stages: provisional and operational evaluation of releases, intervention itself and recovery. Modelling of isoconcentration and isodeposition curves is part of the provisional evaluation. In addition, an original parametric method for risk evaluation takes into account the magnitude and time of the release and its content in "critical" radionuclides, e.g. iodines. The intervention modalities are planned according to the geographic and demographic characteristics of the site. The areas and number of people involved are obtained by means of a subprogram, ISODOSE, based on the coordinates of the point source. A forecast of the shape of indirect trajectories can be gained from a meteorological and orological study of real sites. The routing of the control teams and the various types of countermeasures around each site are specified. The effectiveness of the various countermeasures, such as relocation and sheltering, has been evaluated for the optimisation of the intervention and for the definition of objective criteria such as the population doses that could be received if no countermeasures were applied during a given time after the accident. The weather conditions and the appropriateness of some extensive countermeasures, such as spraying by planes, have also been taken into account in the study of the evolution of contamination in an urban environment.