Implementing internal independent nuclear safety oversight – Insights from a Nordic empirical case study

• Experiences related to the implementation of internal independent nuclear safety oversight (INSO) were studied. • Perceived contributions to nuclear safety and implementation challenges were identified. • Internal independence is a multidimensional continuum that involves balancing between isolation and losing perspective. • The ideal form of INSO should apply a more systemic approach, and complement “defence-in-depth” with “challenge-in-wide”. Independent Nuclear Safety Oversight (INSO) is an internal organizational function that aims to provide nuclear licensee organizations an independent overview of their nuclear safety situation. This article provides an overview of the implementation and impact of INSO based on an empirical, qualitative case study in three Nordic nuclear power companies. INSO was perceived to contribute to nuclear safety by providing independent challenge of the line activities and decisions, advising and supporting the line organization and senior management, and providing an independent overview of nuclear safety. The implementation challenges were often managerial and included the underutilization of INSO recommendations by top management, lack of agreement between INSO and the line organization regarding INSO’s role, tasks, and results, and the unavailability of resources for conducting INSO activities. Our results also suggest that internal independence is not a black and white phenomenon and that there is no universally correct level of independence. Internal independence involves continuously and intelligently managing the tension between being isolated and losing perspective. The article concludes with recommendations for improving the effectiveness of INSO in global nuclear industry and suggests future development needs.