[en] After an introduction, several articles comment and discuss the consequences of nuclear accidents for health and for the environment at the light of what happened in Chernobyl and Fukushima. The authors also comment and discuss the acceptable dose levels, the way the nuclear risk is perceived by the population or has been treated in France in the case of Chernobyl, the issue of evacuation standards, some false ideas propagated by some media about the way to resist to radioactivity, and the issue of phasing out nuclear. The articles are entitled: 'From Chernobyl to Fukushima, the risks of radioactivity' (Andre Aurengo), 'Radioactivity: which doses?', 'Perception of the nuclear risk' (Nicolas Gauvrit), 'Must evacuation standards in case of nuclear accident be reviewed?' (Herve Nifenecker), 'Health consequences of nuclear accidents' (Roland Masse), 'A new world record of probabilities' (Nicolas Gauvrit), 'The urban legend in front of reality' (Yann Kindo), 'Fukushima: the environmental consequences' (Henri Metivier), 'To go without food against radioactivity?' (Brigitte Axelrad), 'Can we do without nuclear?' (Claude Acket and Pierre Bacher)