Resumen
The paper presents an overview of the lessons learned from past nuclear reactor accidents and their relevance for the development of nuclear safety culture. Although the term "safety culture" emerged after the Chernobyl accident, the factors that contributed to earlier accidents, of which the most notable was the accident of Three Mile Island Unit 2, are also relevant for nuclear safety culture. As regards the Fukushima Daiichi accident from 2011, safety culture was once again brought into discussion. In this paper we will analyze the lessons learned from past nuclear accidents by making use of the 37 attributes of a strong safety culture, promoted by the IAEA.