The ongoing spatial turn of both energy research and transition studies have highlighted the need for a stronger understanding of spatial configurations to grasp the heterogeneity of energy transition pathways. While previous works predominantly focused on territorial context inhibiting or driving renewable energy development, the dynamics of incumbent energy systems remain understudied. This is particularly the case for nuclear power, which epitomizes the diversity of energy trajectories in decarbonization policies, swinging between “renaissance” and “decline”. Consistent with energy geographers’ call for new research characterizing the path dependencies which strengthen incumbent systems, this paper offers to assess the spatial embeddedness of nuclear power plants by comparing the closure of two facilities in Germany (Neckarwestheim) and France (Fessenheim). The two case studies were chosen for the divergent intensities of controversies triggered locally by their shutdown. We introduce Raffestin’s conception of relational territoriality, different from the behavioralist and Sackian approach previously used in energy geography, in order to identify and describe the spatial elements of nuclear power path dependencies. Results show more robust relational territorialities in Fessenheim than in Neckarwestheim. Opposition against closures appears stronger where the facility induced deeper forms of spatial embeddedness. The path dependency of nuclear power plants is co-produced by their territory preexisting spatial characteristics and social representations, the spatial transformative power of the monetary flow occasioned by the plants, the actions of the site’s workers and the normative elements governing its spatial existence. However, results show no direct influence of local communities on the elaboration of national nuclear policies.