AbstractFusion is seen as a much ‘cleaner’ energy than fission, and a resource for clean energy in the far future. However, being a form of nuclear energy, fusion shares with fission most of its safety problems. This study concerns the assessment of both the short term and the long term hazards associated with fusion, compared with the same figures for fission reactors. Fission data derive from well-known PWR safety assessments, and in particular from the Italian project Progetto Unificato Nucleare (PUN). Fusion data derive from the latest findings of the European Safety and Environmental Assessment of Fusion Power (SEAFP) programme. Concerning inadvertent intrusion in a radioactive waste disposal site and long-term degradation for fusion, this analysis was performed in the frame of the SEAFP studies, while for fission data are taken from typical European waste disposal sites. In all relevant cases, evaluation of associated risks is carried out, with a comparison of the obtained results.