This research project aims to study knowledge exchange and combination processes, at interorganizational level and in the very long term. Those are complex processes and raising many issues, particularly from the perspective of managing and sustaining interorganizational knowledge, in the long term and in high-risk contexts, to ensure safety. In order to study this and respond to concrete issues arising from our collaboration with a field actor, we are conducting a qualitative research, through a Design methodology. The objective is to propose an organizational architecture in order to resolve these issues.