The 9/11 attacks prompted the development of an international nuclear security regime. States are expected to adopt legislation and institutionalize measures to ensure cooperation among stakeholders and create their own national nuclear security regimes. This article evaluates the steps taken by Turkey, a newcomer in nuclear energy. It argues that while Ankara has acted in line with its traditional conception of security, this is not enough. The inadequate cooperation and coordination among stakeholders, and the insufficient development of a security culture specifically oriented to nuclear energy, leave the country vulnerable. The analysis explains the vulnerabilities and incomplete tasks, and proposes actions necessary for Turkey to create a sound national nuclear security regime.