This paper compares potential nuclear fuel cycle strategies – once-through, recycling in thermal reactors, sustained recycle with a mix of thermal and fast reactors, and sustained recycle with fast reactors. Initiation of recycle starts the draw-down of weapons-usable material and starts accruing improvements for geologic repositories and energy sustainability. It reduces the
motivation to search for potential second geologic repository sites. Recycle in thermal-spectrum nuclear reactors achieves several recycling objectives; fast nuclear reactors achieve all of them.