Disposal R&D in the Used Fuel Disposition Campaign: A Discussion of Opportunities for Active International Collaboration

For DOE's Used Fuel Disposition Campaign (UFDC), international collaboration is a beneficial and cost-effective strategy for advancing disposal science with regards to multiple disposal options and different geologic environments. While the United States disposal program focused solely on Yucca Mountain tuff as host rock over the past decades, several international programs have made significant progress in the characterization and performance evaluation of other geologic repository options, most of which are very different from the Yucca Mountain site in design and host rock characteristics. Because Yucca Mountain was so unique (e.g., no backfill, unsaturated densely fractured tuff), areas of direct collaboration with international disposal programs were quite limited during that time. The decision by the U.S. Department of Energy to no longer pursue the disposal of high-level radioactive waste and spent fuel at Yucca Mountain has shifted UFDC's interest to disposal options and geologic environments similar to those being investigated by disposal programs in other nations. Much can be gained by close collaboration with these programs, including access to valuable experience and data collected over recent decades. Such collaboration can help to efficiently achieve UFDC's long-term goals of conducting 'experiments to fill data needs and confirm advanced modeling approaches' (by 2015) and of having a 'robust modeling and experimental basis for evaluation of multiple disposal system options' (by 2020). This report discusses selected opportunities of active international collaboration, with focus on both Natural Barrier System (NBS) and Engineered Barrier System (EBS) aspects and those opportunities that provide access to field data (and respective interpretation/modeling) or allow participation in ongoing field experiments. This discussion serves as a basis for the DOE/NE-53 and UFDC planning process for FY12 and beyond