Employing the example of France’s civil nuclear program, we connect political opportunity structures (POSs) to mechanisms of knowledge production, identifying how opposing stakeholders generate knowledge about a controversial technology. A history of nuclear dependence in France creates a context that praises, normalizes, and rationalizes nuclear energy while stigmatizing attempts to question or contest the nuclear industry’s dominant position. Integrating Bond’s knowledge-shaping process with Coy and colleagues’ concept of oppositional knowledge, we consider how the broader social, political, and economic context influences opposing stakeholder assessments of nuclear energy. Employing qualitative semi-structured interviews, we offer unique insight into the French nuclear debate, discussing the role of POS in shaping knowledge production.