Because nuclear power development entails massive initial investments in power plants, along with institutional innovations in regulation, law, and basic physical infrastructure, there are strong grounds to support the pervasiveness of the central state in the industry. Furthermore, considering the scale economies in reactor installation, standardization in design, and enhanced learning by doing, little scope remains for the consideration of decentralized business interests. This article argues that competition, in the sense of rivalry between firms, can nonetheless be a driving force behind the nuclear industry. To illustrate the point, we draw a comparative, eventful history of two Iberian nations, Portugal and Spain: Portugal has failed several attempts to introduce nuclear power, while Spain has become one of the largest nuclear power nations in Europe. A fine-grained analysis of the circumstances surrounding the nuclear history of both countries is presented, highlighting the key variables of business history and the role of the central state and political actors in economic policy.