[en] Effective knowledge management (KM) enhances a firm's capability to assimilate, create and exploit knowledge. KM is widely recognized in both the management literature and in practice as an important driver of long-term organizational performance and a necessary condition for sustained commercial success. Its role is particularly important in technology intensive industries such as the nuclear industry. Knowledge management practices, if effectively applied in nuclear power plants, have the potential to be an important enabler of operational and safety performance improvements, of reductions in operational and personnel risk, and of opportunities for plant design improvement. However, although a number of researchers have studied the relationship between KM practices and firm performance, little empirical evidence exists to support these claims in the context of the nuclear energy industry. Knowledge management has only recently caught the attention of the nuclear industry. Various nuclear power plants (NPPs) around the globe have begun to recognize the strategic importance of KM initiatives in achieving sustained high levels of operational performance. Although these organizations have been involved in KM-related activities for some time, they typically have not been recognized as such. Thus they have not been viewed and managed from a KM perspective. Several NPPs have been early adopters of KM practices in the nuclear industry, and have been proactive in implementing company-wide KM programs. However, at other NPPs, the concepts and benefits of KM are only beginning to be understood and are not yet applied. The various approaches taken to KM and the relative benefits obtained from KM initiatives vary from station to station. Little is known as to how prevalent specific KM practices are and how effective they have proven to be. There is little prior research to guide NPP managers in the implementation of KM. Research is needed to determine what practices are effective and what benefits can be expected. This thesis investigates the impact of KM practices on organizational effectiveness and operational performance in NPPs using quantitative research approaches (i.e. a large scale industry survey). It explores the effect of KM practices on the quality of knowledge processes and the resulting impact on organizational performance. Specific contextual aspects of the nuclear industry in general and of nuclear power plants in particular are identified and considered in the process. A theoretical framework is developed and subsequent hypothesis are derived and tested. Independent variable constructs include the level of support for KM practices and the effectiveness of technology support. Intermediate variable constructs considered are the quality of knowledge processes and the degree of supportive organizational culture. Dependent variables include organizational effectiveness and operational performance. Subconstructs and measures are developed and explained in detail. In conclusion, the goal of the research is to show the nature and extent of the influence of KM practices on NPP organizational performance, and the specific mechanisms by which this occurs. (author)