The dissertation seeks to explain the pattern of nuclear power development in the United States, treating the subject as a case study of how major infrastructural development choices are made in a modern capitalist economy. Because such decisions are laden with uncertainty and sensitive to numerous scale economies, different technologies may be able to win enduring market dominance if first in capturing scale and other "critical mass" efficiencies. Recognition of this potential can spur political-economic interests to attempt to capture critical mass for congenial technologies, in pursuit of economic rents or positive political externalities. The main concept adduced in the thesis to organize nuclear history is that of an Official Technology (OT). The latter enjoys strong state support, the promoted image of the "coming technology" and capture of critical mass advantages. The dissertation analyzes the incentive key political-economic interests had for promoting nuclear power to OT status 1946-1974 and the mechanisms used by these groups to facilitate nuclear explansion. An "OT differential", tallying the microeconomic impact of nuclear's capture of OT status is calculated. Included in the differential are the benefits of: scale economies, learning curve cost reductions, federal subsidies and regulatory incentives, misleading information environments and bureaucratic momentum. Nuclear's decline after 1974 is tied to the erosion of this differential by a political challenge to the technology's OT status. The dissertation's key claim is that the OT framework can uncover socio-political roots for technical choice decisions that appear determined solely by engineering parameters in a static, a-historical framework.