The CO2InnO project [1] is a France-Germany cross-border living laboratory, investigating several aspects of the energy transition at the local scale. One of these is the study of the environmental impacts of the upcoming Fessenheim Nuclear Power Plant (NPP) decommissioning. NPP decommissioning have been relatively neglected in academic environmental impact studies, in particular through the lens of life cycle assessment (LCA), with only 3 studies to date [2-4]. In parallel, there has been relatively low interest in radiological impact assessment in the field of LCA, in particular due to the lack of an appropriate and consistent life cycle impact assessment (LCIA) framework [5] . Two recently developed methodologies attempt to remedy this problem regarding impacts on human health [6] : – UCrad, built as a radiological counterpart to the widely used USEtox, is designed to produce globally averaged results adapted for technology evaluation & comparison. – CGM, drawing on analytical modeling of established risk assessment studies, is designed for plant-scale evaluation in a screening context. The development of UCrad have also been pushed from the midpoint/effect level, in Sievert (Sv), to the endpoint/damage level in Disability- Adjusted Lost Years (DALYs) [7]. The approach can easily be transferred to CGM by adapting the population considered. Furthermore, the time scale of an NPP decommissioning (at least 15 years) suggest that population evolution could cause bias in the characterization factors (CFs) used, a fortiori the obtained results, if not dynamically adjusted. CF (endpoint) = CF (midpoint) · Effect Factor · Population We resolve this by using population datasets designed for consistency with the different shared socio-economic pathways (SSPs). These datasets are imported in the QGIS open source software [8], and extracted population values are used to construct appropriate CFs for the prospective endpoint-level assessment. This allows us to compute the midpoint & endpoint radiological impacts on human health expected to occur during the Fessenheim NPP decommissioning, compare “static” & prospective LCA estimates, and to highlight perspectives for the development of the UCrad & CGM LCIA methods. References [1] CO2InnO Project. Interreg Upper Rhine 2021–2027, A1.3. [2] Wallbridge, et al., 2013. Life cycle environmental impacts of decommissioning Magnox nuclear power plants in the UK. Int J Life Cycle Assess 18, 990–1008. [3] Seier, M., Zimmermann, T., 2014. Environmental impacts of decommissioning nuclear power plants: methodical challenges, case study, and implications. Int J Life Cycle Assess 19, 1919–1932. [4] Iguider, M. et al., 2024. Life cycle assessment of an upcoming nuclear power plant decommissioning: the Fessenheim case study from public data. Int J Life Cycle Assess. [5] Paulillo, A. et al., 2018. Radiological impact assessment approaches for Life Cycle Assessment: a review and possible ways forward. Environ. Rev. 26, 239–254. [6] Paulillo, A. et al., 2020. Radiological impacts in Life Cycle Assessment. Part I: General framework and two practical methodologies. Science of The Total Environment 708, 135179. [7] Paulillo, A. et al., 2023. Characterizing human health damage from ionizing radiation in life cycle assessment. Int J Life Cycle Assess 28, 1723–1734. [8] QGIS Development Team, 2024. QGIS geographic information system v3.36.3 (Maidenhead). QGIS Association.