Drawing on the conduct of the immediate risk assessment process carried out in the case of the Vincennes Preschool and on the contribution of pluralistic expertise as implemented within the framework of the Nord-Cotentin Radioecology Group, this article highlights the specific role of public expert bodies. It is recalled that, following a number of accidents or crises, French public authorities established public institutes responsible for risk prevention, whose activities take place prior to decision-making. One of the roles of these bodies is to make their expertise available to other actors in society. This function is all the more important given that, as demonstrated by the opinion polls cited in the article, the various crises that have occurred have resulted in a lack of trust in institutional actors, even though they are credited with a high level of competence. Making public expertise accessible does not mean that the goal is to impose a monopoly over it. On the contrary, particularly in complex or potentially contentious cases, the aim is to foster a pluralistic debate. The article successively comments on the recommendations of the Committee on Precaution and Prevention—a committee attached to the Minister of the Environment—which emphasize the “sharing of expertise” and the experience gained by the pluralistic expert group tasked with addressing a scientific controversy surrounding the nuclear fuel reprocessing plant in La Hague. The article concludes by mentioning the information-sharing networks developing in Europe regarding what is known as the “new governance of high-risk activities,” as well as the alliances being formed among public expert bodies. (R.A.)