"More demand for electricity and concerns about greenhouse gas emissions have increased interest in nuclear power, which does not rely on fossil fuels. However, concerns remain about the radioactive spent fuel that nuclear reactors generate. The Department of Energy (DOE) issued a research and development (R&D) plan to select nuclear fuel cycles and technologies, some of which reprocess spent fuel and recycle some nuclear material, such as plutonium. These fuel cycles may help reduce the generation of spent fuel and risks of nuclear proliferation and terrorism. GAO was asked to review (1) DOE's approach to selecting nuclear fuel cycles and technologies, (2) DOE's efforts to reduce proliferation and terrorism risks, and (3) selected countries' experiences in reprocessing and recycling spent fuel. GAO reviewed DOE's plan and met with officials from DOE, the nuclear industry, and France and the United Kingdom.