In the last century, physicists have discovered the possibility of using energy associated with nuclear forces. The course of events of the atomic project and the history of the "peaceful atom" are covered, the reasons, consequences, prospects of these important components of human security are briefly described. This is important for Ukraine, where six nuclear power plants produce almost 60% of the electricity consumed by the population and industry. One of the sections is devoted to the ethics of scientific research in this field. The book is intended for a wide range of teachers, students, students and graduate students working in the field of physics.