Since 2012, in an effort coordinated by Lawrence Berkeley National Laboratory, Spent Fuel and Waste Disposition (SFWD) Campaign has advanced active collaboration with several international geologic disposal programs in Europe and Asia. Such collaboration allows the SFWD Campaign to benefit from a deep knowledge base in regards to alternative repository environments developed over decades, and to utilize international investments in research facilities (such as underground research laboratory testing and modeling), saving millions of R&D dollars that have been and are being provided by other countries. To date, SFWD’s International Disposal R&D Program has established formal collaboration agreements with several international initiatives and various international partners, and national lab scientists associated with SFWD have conducted specific collaborative R&D activities that align well with its R&D priorities. Guiding principles for selection of collaboration options and activities have been as follows:
- Focus on activities that align with the strategic direction of the SFWD campaign and complement ongoing disposal R&D (e.g., the science and engineering tools developed in SFWD are tested in comparison with international experiments).
- Select collaborative R&D activities based on technical merit, relevance to safety case, and cost/benefit, and strive for balance in terms of host rock focus and repository design.
- Emphasize collaboration that provides access to and/or allows for participation in field experiments conducted in operating underground research laboratories in clay, crystalline, and salt host rock, which are not currently available in the U.S.
- Focus on collaboration opportunities for active R&D participation of U.S. researchers and close collaboration with international scientists on specific R&D projects relevant to both sides.
Key Issues Tackled in Current and Planned Portfolios:
- Near-Field Perturbation: How important are thermal, mechanical, and other perturbations to a host rock (such as clay and salt), and how effective is healing or sealing of the damage zone in the long term? How reliable are existing predictive models for the strongly coupled thermal-hydrological-mechanical behavior of clays and salts?
- Engineered Barrier Integrity: What is the long-term stability and retention capability of backfills and seals? Can bentonite be eroded when in contact with water from flowing fractures? How relevant are interactions between engineered and natural barrier materials, such as metal-bentonite-cement interactions? Is gas pressure increase and gas migration a concern for barrier integrity?
- Flow and Radionuclide Transport: What is the effect of high temperature on the diffusion and sorption characteristics of clays (i.e., considering the heat load from dual-purpose canisters)? What is the potential for enhanced transport with colloids? Can transport in diffusion dominated (clays, bentonites) and advection dominated systems (fractured granites) be predicted with confidence?
- Demonstration of Integrated System Behavior: Can the early-time behavior of an entire repository system, including all engineered and natural barriers and their interaction, be measured and demonstrated? Can this integrated behavior be reliably predicted? Are the planned construction and emplacement methods feasible? Which monitoring methods are suitable for performance confirmation? How reliable are performance assessment models?
Current LBNL activities related to active international collaboration between UFD and other countries are within the following multinational and multi-partner initiatives that promote active R&D in nuclear waste disposal science:
- DECOVALEX (EESA Summary page; Full Project website)
- Mont Terri Partnership
- SKB Task Force
- COSC Collaboration
Publication: Milestone report: International Collaboration Activities in Different Geologic Disposal Environments
Contact: Jens Birkholzer