The research and manufacturing associated with the nuclear materials production has resulted in a significant quantity of waste that poses health, environmental, and proliferation hazards. One of the greatest challenges today is the cleanup and remediation of the highly complex, radioactive wastes and contaminated areas surrounding these facilities.
The scientific development of waste forms has evolved through different regulatory histories which, has motivated different approaches to designing, testing, and evaluating each waste form. Consequently, many of the challenges related to vitreous waste forms are well-known whereas, comparatively less fundamental and mechanistic understanding is available for cementitious and other waste forms. These different histories have resulted in significantly more resources expended on developing glass and vitrification technologies compared to other waste forms. Nevertheless, revolutionary advances in glasses and cementitious materials, as well as wholly new storage materials and concepts are needed to ensure the long-term stability and safety of waste storage.
Long-term performance, the criteria on which waste forms are evaluated, requires understanding the fundamental physical and chemical processes that occur in waste forms but, is challenging to predict and correlate across timescales spanning days to millennia. The complexity of waste inventories precludes a single remediation option. New approaches to waste form material synthesis combined with recent advances in computational and experimental approaches, provide the foundation and pathway to address waste remediation challenges. Hierarchical materials are a class of materials that have the potential to effect the aggregate safety, cost, and efficacy of nuclear waste immobilization and sequestration.