Gas Centrifuge Theory and Development: A Review of U.S. Programs

This article gives a historical and technical review of the U.S. gas centrifuge efforts between 1934 and 1985. The first section tells of how the United States initially led in centrifuge design, only to abandon the still-immature technology in the midst of the Manhattan Project. While interest in the technology continued in Europe, the United States decided that centrifuges were not a viable alternative to existing gaseous-diffusion plants. Five years later, U.S. spies learned of important Soviet achievements in centrifuge design, which, it appeared, might place centrifuges in direct competition with gaseous diffusion. When combined with European enthusiasm for the centrifuge, the United States faced the prospect of losing its control on the enrichment market in the West. Accordingly, the United States organized a program to rebuild its centrifuge dominance. Over the next 25 years, it led the world in machine performance but ultimately failed to commercialize its designs for a variety of reasons. The basic specifications and performance data for several of the U.S. centrifuges designed and tested during these years are reported here for the first time in the public domain. The United States also made a number of contributions in the theoretical domain that were openly shared over the course of the U.S. program. Most of these fell into the field of fluid dynamics, developed to guide the design and optimization of centrifuges. The most important elements, especially those relating to the calculation of separative power, are described in Theoretical Developments. These are of interest to policymakers because they can be used to predict the rate at which centrifuges produce fissile material for nuclear weapons, an important factor for nuclear nonproliferation. They are also used in calculations related to multi-isotope separation, which is important for nuclear forensics. Examples of both kinds of policy analysis are given in articles by Glaser1 and Wood2 appearing in an earlier issue of Science and Global Security. The U.S. theory is used here to derive a simple equation that enables policy-makers to make good estimates for the separative power of a real centrifuge by knowing only its length and speed.