Advanced Reactors: Proliferation and Terrorism Concerns

Over the last few years, there has been renewed interest in the United States and internationally in the development of advanced, non-light water reactors and their associated fuel cycles. These include liquid-metal-cooled, gas-cooled, and molten-salt-cooled reactors. However, there has been insufficient attention to the impacts of commercialization and deployment of these systems on global risks of nuclear proliferation and terrorism. Many proposed designs would require high-assay low enriched uranium (HALEU). Some would require large supplies of weapon-usable materials such as uranium-233, plutonium, or other transuranics. And some concepts involve on-site reprocessing, either on a continuous or batch-fed basis. Although some of these fuel cycles are of greater concern than others, all would introduce significant challenges for safeguards and security. For instance, while HALEU is not currently defined as direct-use material, it is in a more sensitive security category than low-assay LEU. This has not been a major problem to date because the demand for HALEU has been limited. More analysis is needed of the implications of the development of a global infrastructure for production, transport, storage, and processing of large quantities of HALEU. Also, it is unclear what resources and tools reactor operators would need to manage, secure, and accurately measure the large flows of weapon-usable materials separated by on-site reprocessing plants. This paper will discuss these issues and others for a number of advanced reactor designs.