The US advanced fuel cycle program: Objectives and accomplishments

Full text: The US Department of Energy has been running for approximately a decade an advanced fuel cycle program (currently named the Fuel Cycle R and D Program) devoted to lessening both the environmental burden of nuclear energy and the proliferation risk of accumulating Used Nuclear Fuel. Until very recently, this program was technically focused on achieving an optimized symbiosis between fuel cycle options on one hand, and the US geological repository on the other, with a relatively short term deployment focus. Following detailed technical analyses, this focus led to the selection of a limited set of technologies that were expected to both meet specific geology related criteria, and would be based on limited extrapolations of existing technologies. Recent developments in the US indicate that the Yucca Mountain repository might not be anymore the geology of reference; furthermore, the need for advanced fuel cycles has been postponed to the middle part of the century, with increased reliance on temporary storage of Used Nuclear Fuel in the interim. Consequently, the Fuel Cycle R and D Program is being redirected towards a science based, goal oriented focus, driven by the following three considerations: 1. the program is currently examining a broad set of options, including different geologic media and transmutation technologies, in order to understand their relationships and provide information for later decisions. 2. the R and D component of the program is focused on acquiring the basic understanding of key phenomena, defining the relevant challenges, and acquiring the basic tools necessary to resolve them. 3. the timeline of the program allows for a deployment of the successfully demonstrated technology in the 2040-2050 timeframe; this allows us to consider technologies that are not yet mature, but that might provide significant improvements in performances. The technical program is articulated along the following elements: - a systems integration task that analyzes the relationships between technologies and defines requirements on each technology to achieve overall system objectives. - a separations research programs that is aimed at understanding the fundamentals of actinide chemistry, in order to develop processes that achieve specific separation goals with very low losses - a fuels research program that is also aimed at a better understanding of the fundamentals of fuel behavior, in order to design minor actinide containing fuels with high burnup capabilities. - A fast reactor development program aimed at reducing the cost of fast reactors, with increased safety performance, - Significant efforts are also being devoted to achieving a better understanding of geologic repository options, and to the development of better safeguards techniques. The program also contains a significant Modeling and Simulation component. (author)