The survey: an indispensable operation in a post-accident situation, a substantial organisation to be planned

After a radiological accident, the objectives of the census are to assess the size of various populations involved, to facilitate the individual dosimetry, to give access to medical care, to allow epidemiological studies, to manage the indemnification of the victims. The census has to be done as quickly as possible before the population scatters and becomes lost to any follow-up. Population who benefit of protective actions justify active and exhaustive census. Population concerned by the accident for living close to the central justify active representative sampling joint to a passive census. During the census, collecting the exact identity and contact-numbers of the person is essential in order to be able to cross-check individual information on dosimetry, medical care, or protective action. A short questionnaire is ready to use for this purpose. The organisation concerns also the data key-boarding, its centralization, its cross-checking between sources, its conservation and its analysis. The achievement of this census will require a strong organisation of the network that it is compulsory to plan before any accident and to test in crisis exercise. (authors)