Like many industries, the nuclear power industry in Sweden is currently facing the challenges of a major generational change. To meet these challenges, alongside the demands for a high level of security, the industry has attempted to standardise its mode of operations as far as possible. Apart from various technological fixes and safety devices, manuals and instructions have been modelled for every conceivable situation, or course of events; documentations and formal systems of co-ordination that become larger and larger, and more and more detailed. In high-risk industries there is a tendency to equate learning with changes in external patterns of behaviour, as against fixed standards, typically among operating staff. The acquisition  of professional skill, on the other hand, is the result of participation in practice. From this point of view, rather, learning is the outcome of reflection, upon actual events and experiences. Recurrent training can be used to promote formalisation, but also to explore and reinforce the experience based knowledge of skilled operators; between these approaches, the former prevails. Accidents and incidents incessantly put in question what is commonly referred to as the safety culture of various power plants, and subsequent to the misfortunes at Forsmark 1 in 2006, the accident was described as the culmination of a longterm decline in safety culture. The strong requirement for security and control is a cause of formalisation, whereas the need to support reflection as formation of professional skill tends to be omitted. Even so, experience based skill and knowledge remains a substantial consituent of what could be regarded as a dependable safety culture. Codified knowledge must be interpreted and applied in practice. Furthermore, experienced professionals, from encountering a great variety of situations, seem to develop what can be described as the skill of anticipation, and, as shown in connection with the incident at Forsmark 1, an ability to handle the unexpected. The urge for formalisation raises certain concerns: that of the primacy of defining the containments of professional skill, the impact and resilience of local knowledge and diversity, and the hollowing out of ability and skill within work-life organisations. The “human factor”, that is the operating staff, is commonly made responsible for established accidents and incidents. Even so, experienced personnel are able to manage a variety of unforeseen events and disturbances, that sometimes occur in high-risk technology industries. At times, on the contrary, the human factor saves technology, instead of the other way around. This study explores the concept of safety culture within the nuclear power industry from an epistemological perspective. It discusses the use of recurrent training, and the role of experience based skill and knowledge in the operating of Swedish power plants. What methods can be employed to support experience based knowledge as an essential complement to standardised work processes, codified knowledge, or benchmark strategies? Principles of formalisation need to be supplemented with a more thorough exploration of professional skill, in which a distinction between behaviour and responsibility can be made. / QC 20110906