Monitoring the Long-Term Performance of Engineered Containment Systems for Radioactive Waste: What an We Learn From Ecological Monitoring Approaches?

摘要

Due to technical and economic limitations, chemical and radioactive wastes will require isolation in engineered containment facilities at many sites including the former nuclear weapons facilities within the Department of Energy (DOE) complex. Also, while our experience with currently favored designs is only a few decades at best, the materials being isolated may require effective containment for hundreds to thousands of years. It is becoming clear that without monitoring of both the engineered barriers and the associated institutional controls and intervention, engineered containment systems will ultimately fail.Monitoring of engineered barriers is often limited to groundwater monitoring and physical inspections. The database managed by the DOE Office of Legacy Management provides information concerning barrier performance at uranium mill tailings sites over several years to decades. The current monitoring approach that focuses on groundwater, while necessary for regulatory compliance, does not provide an early warning. Rather, it provides detection of barrier failure as opposed to indications of barrier degradation. Identification and monitoring of precursors to failure are needed. Furthermore, existing monitoring strategies typically omit ecological monitoring. Additional understanding of the interaction between barrier degradation and ecological dynamics could provide a basis for monitoring and managing barriers as well.Monitoring the long-term performance of systems of interest is a challenge not only to the Department of Energy but to other institutions and federal agencies. National Environmental Research Parks (NERP), National Estuarine Research Reserves (NERR), and Long Term Ecological Research (LTER) areas operated by the US government agencies are designed with the specific goal of intensely monitoring and conducting research over long time scales and within diverse geographical settings. This presentation will address the importance of understanding ecological interactions as they are expressed over decades and centuries in respect to federal long-term monitoring programs, and to delineate how multifaceted sets of ecological data can be used to interpret the overall integrity of ecosystems. Furthermore, important components of these programs will be identified that may have merit in the design of long-term monitoring programs for hazardous chemical and radioactive waste sites.