Importance of risk assessment in the management of radioactively contaminated areas.

B. Cessac, A. Oudiz, J. Brenot, J.P. Maigné, P. Santucci, M.C. Robé, P. Charbonneau Actes du congrès ECORAD, 3-7 sept 2001, Aix en Provence, France Radioprotection - Colloques, volume 37, C1-1193/ C1-1198.

At the request of the French ministries of Health and Environment, the IRSN has realized a methodological guide for aiding to the management of radioactively contaminated sites. This guide gives an operational framework to all stakeholders concerned by the management of such sites. It deals with industrial sites to which current nuclear regulation do not apply. The methodology consists of six stages going from the site characterization by radioactivity measurements to the definition of remediation strategies. Between them, the risk assessment is a stage of particular importance which takes place in two steps according to the importance of the situation to be treated. Firstly, a simplified risk assessment (SRA) supplies a dosimetric overview of the site based on individual dose calculations for generic scenarios of use (residential area, school, offices, ...). Secondly, a detailed risk assessment (DRA) is needed when the SRA shows a level of dose judged too important for the potentially possible uses for the site. The DRA needs a finer characterization of the site and the exposure situation. In every case, the methodology applied should be optimised and imply the various stakeholders in a process of information and dialogue.