Basic Research Needs for Geosciences - Energetics Meetings and ...

APPENDIX 1: TECHNICAL PERSPECTIVES RESOURCE DOCUMENTFigure 7. The existing U.S. nuclear fuel cycle. Also shown are proposed modifications involvingfuel reprocessing to the back end of the fuel cycle, involving fuel reprocessing (from DOE2006a).The nuclear fuel cycle is a key concept when discussing a sustainable future for nuclear energyand nuclear waste management (see Figure 7). To the first order, there are two approaches to thenuclear fuel cycle. An open (or once-through) fuel cycle, as currently planned by the UnitedStates, involves simply disposing of spent nuclear fuel as waste within a geologic repository.New nuclear fuel is only derived from mined uranium. In contrast, a closed (or recycle) fuelcycle, as currently planned by other countries (including France, Russia, and Japan), involvesreprocessing spent nuclear fuel by separating useable actinides to put into new fuel rods anddisposing of other elements that are inappropriate for nuclear fuel in a geologic repository.It is important to note that regardless of the fuel cycle approach, a geologic repository is requiredto dispose of long-lived radioactive material. The constraints for a repository design areprimarily the type of waste form(s) to be disposed of and the inventory of radionuclides theyAppendix 1 • 24Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systems