This publication provides guidance for all steps in performing safety reassessments for research reactors in the light of the feedback from the Fukushima – Daiichi accident. Although it primarily focuses on operating research reactors, the guidance provided by this publication also applies to research reactors that are in the design and construction phases or in an extended shutdown state. It is not intended to replace or supersede any of the requirements or guidance provided by the relevant IAEA safety standards, including those on safety analysis, evaluation of seismic and external hazards, and emergency preparedness and response for research reactors. However, this Safety Report should be used in close conjunction with these safety standards, whereby the main users will be operating organizations, regulatory bodies, design organizations and other entities involved in the safety of research reactors.