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

APPENDIX 1: TECHNICAL PERSPECTIVES RESOURCE DOCUMENTMost nuclear materials disposal or isolation will occur within several hundred meters of thesurface, either within the zone of sediment and rock that are unsaturated by ground water, orwithin the sediment or rock that is fully saturated with ground water, but above any deepgeological aquifers. Again, in simplest terms, disposal of nuclear waste requires developingbetter understanding of chemical (radionuclides, metal corrosion products, and other wastederivedmaterials) migration processes within complex geological media outside the engineereddisposal system in case of leaks. The geological disposal approach provides a deep location toprevent human intrusion at some point in the future since isolation has to be maintained for manythousands of years. A critical scientific aspect is that the emplacement of the engineered disposalcanisters will occur in unpressured environments at depths that may communicate with theatmosphere and/or the hydrosphere if the engineered barriers are breached. Understanding thescientific basis for nuclear materials disposition will also contribute to challenges faced by DOEin its environmental cleanup mission.The scientific challenge for these two technologies is to build systems-level understanding thatcan provide unprecedented public safety margins. Systems-level understanding is ultimatelybased on knowledge of the systems’ components and processes at spatial scales ranging down tothe atomic level and time scales up to thousands of years. Scientific understanding today isadequate to begin to move forward with the proposed technologies, but it is our responsibility tocontinue research to provide the best possible implementation of these technologies over thesucceeding decades. Some uncertainties about the evolution of the isolation environments overthe long-term will remain, even in state-of-the-art designs. Thus, continuing improvements inunderstanding the chemical and physical changes to geological systems potentially will reducerisk and cost, and expand confidence in predicted performance.Success in reaching this new understanding will have a much broader impact on DOE’s appliedprograms than just in these two energy areas, because of the commonality of challenges diverseoffices face, for example in geothermal energy, oil and gas development, environmentalremediation and waste management. The improved understanding of the critical processesassociated with these two new energy technologies will be used to design advanced geochemical,hydrologic and geophysical measurement technologies, enhance our ability to predict andmonitor subsurface processes at a much higher resolution, and enable us to use measurementsand monitoring capabilities for verifying system behaviors.Appendix 1 • 2Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systems