This basically educational book is intended for all involved in nuclear facility safety. It dissects the principles and experiences conducive to the adoption of attitudes compliant with what is now known as «safety culture». This book is accessible to a wide range of readers. Jacques Libmann is an expert acknowledged both for his insight into the principles underlying safety in nuclear facilities and for the clear thinking characterizing the courses and lectures he gives both in France and abroad. The International Atomic Energy Agency (IAEA) often calls on him as a teacher in the context of the many training sessions organized throughout all parts of the world concerned by nuclear energy.