For practical reasons, the consequences of nuclear reactor accidents are often measured in economic terms. Figures currently available, however, show significant discrepancies. For this reason, the NEA created an expert group to investigate the methodologies used in calculating the economic consequences of accidents, and the bases for such methodologies. Calculation methods were assessed according to three end uses: for compensation and liability purposes; for accident preparedness and management purposes; and for making electricity-generation choices. The group concluded that comparing numerical results is very difficult, even for estimates made from the same perspective, as they are strongly dependent on "boundary" conditions (such as the accident scenarios used, plant characteristics and amount of radioactive material released). This book provides a summary of the group’s findings and will be of interest to decision makers, experts and accident-consequence modellers.