Following the work of Barbara Adam (1998) and Ulrike Felt (2016), we draw particular attention to ‘timeprints’ in the assessment and selection of radioactive waste management (RWM) options. Using the example of Belgium, we identify four different timeprints mobilized (un)consciously by stakeholders when assessing RWM options, namely trajectorism, promise economy, radioactive waste identity, and multi-situated timeprints. We show that each of these timeprints has a significant impact on the RWM option to be considered and actively determines future radioactive waste management pathways in the form of ‘tacit governance’. ; Following the work of Barbara Adam (1998) and Ulrike Felt (2016), we draw particular attention to ‘timeprints’ in the assessment and selection of radioactive waste management (RWM) options. Using the example of Belgium, we identify four different timeprints mobilized (un)consciously by stakeholders when assessing RWM options, namely trajectorism, promise economy, radioactive waste identity, and multi-situated timeprints. We show that each of these timeprints has a significant impact on the RWM option to be considered and actively determines future radioactive waste management pathways in the form of ‘tacit governance’.