[en] This issue of risk and safety in nuclear industry presents several articles devoted to radiation protection. The first one concerns the rehabilitation of quality of life in the lands contaminated by the Chernobyl accident, it is about the E.T.H.O.S. project in Bielorussia. The second one studies the notion of critical group and details the application on the deep radioactive waste storage. The last article evaluates the making use of the optimization principle of the radiation protection in nuclear power plants. (N.C.)