European clearinghouse: Contributing factors to incidents related to reactivity management

In this paper shortcomings in reactivity management reported to the IAEA Incident Reporting System in the period 1981–2008 are investigated and contributing factors to reactivity management incidents are analysed. The aim of the work was to identify the initiating factors and associated root causes. Five of the seven factors identified for all events were present in the 1999 Shika-1 event where criticality has been unexpectedly reached and maintained during fifteen minutes. Most of the events resulted in changes in procedures, material or staff and management training that are analysed elsewhere. The analysis carried out put in evidence that in several instances appropriate communication based on operational experience feedback would have prevented incident to occur. This work was carried out in the frame of specific studies recently performed by the Joint Research Centre/Institute for Energy (JRC/IE) in the framework of the IE project on the European Clearinghouse on Nuclear Power Plant (NPP) Operational Experience Feedback (OEF).