[en] This document proposes a report of a seminar which aimed at starting an assessment of the implementation of the charter of opening to the society, at identifying possible critical issues of its application and progress margins from the point of view of principles and of practical commitments, at building up propositions for the future implementation, and at being a contribution to current thoughts at the State level in the fields of health and of the environment. A first session proposes assessments of the charter implementation within different public bodies and agencies (ANSES, INERIS, IRSN), overviews of undertaken actions and of relationships developed between stakeholders. A second session reports case studies about practical progresses in opening approaches in different fields: radio-frequency expertise, access to expertise for a safety file of a nuclear installation, polluted soils and sensitive establishments, participatory approach to a health study about a radioactive waste storage site. The document also reports the contents and conclusions of four workshops which respectively addressed the following issues: transparency and confidentiality and communication constraints; influence of opening to expertise on the issue of conflict of interests; objectives of opening with respect to expertise and social acceptability; internal appropriation and learning of the opening approach