In 2021, BASE headed a short workshop called “What do we need to do to trust in models?” at the first edition of the safeND symposium conference (safeND: "Safety of Nuclear Waste Diposal“; Kock et al. 2021). Because of the broad interest people showed in the topic, three consecutive workshops on the topic of “Trust in Models” (TiM) were held between 2022 and 2025.  In this Open Letter, we will present the main points of discussion.

DECOVALEX is an international collaborative project aiming to develop models simulating coupled thermal–hydro–chemical–mechanical processes for use in performance and safety assessment of disposal systems for high-level radioactive waste. BASE actively contributes to Task F, which seeks to build confidence in performance assessment methodologies. This contribution describes recent BASE activities within Task F Salt of DECOVALEX-2023, including lessons learnt and possible future steps.