Advanced Simulation Capability for Environmental Management (Ascem): An Overview of Initial Results

Abstract

The US Department Energy (DOE) Office of Environmental Management (EM) determined that uniform application of advanced modeling in the subsurface could potentially help reduce the cost and risk associated with its environmental cleanup mission. In response to this determination, the EM Office of Technology Innovation and Development (OTID), Groundwater and Soil Remediation (GW&S) began the program Advanced Simulation Capability for Environmental Management (ASCEM). ASCEM is a state-of-the-art scientific tool and approach for integrating data and scientific understanding to enable prediction of contaminant fate and transport in natural and engineered systems. This initiative supports the reduction of uncertainties and risks associated with EM's environmental cleanup and closure programs by better understanding and quantifying the subsurface flow and contaminant transport behavior in complex geological systems. This includes the long-term performance of engineered components, including cementitious materials in nuclear waste disposal facilities that may be sources for future contamination of the subsurface. This article describes the ASCEM tools, approach, and reports and ASCEM programmatic accomplishments completed in 2010.

Identifying key controls on the behavior of an acidic-U(VI) plume in the Savannah River Site using reactive transport modeling

“…These analyses were also performed to demonstrate new UQ capabilities developed as part of the Advanced Simulation Capability for Environmental Management (ASCEM) framework (Williamson et al, 2011), for which the SRS F-Area serves as one of the demonstration sites (U.S. DOE, 2010). The UQ toolset developed for ASCEM and applied in this study is named AGNI.…”

“…In addition, uncertainty quantification (UQ) analyses were conducted using the AGNI tool developed for ASCEM (Williamson et al, 2011) to address the sensitivity of model results to various input parameters affecting the migration of the acidic-U(VI) plume migration at the F Area. A summary of the mathematical formulation for flow and reactive solute transport is provided in the Appendix A.…”

“…To meet these objectives, the multicomponent reactive transport model TOUGHREACT (Xu et al, 2011) was applied in combination of a new tool called AGNI UQ. AGNI UQ has recently been developed as part of the Advanced Simulation Capabilities for Environmental Management (ASCEM) project that is building an open-source, modular, and extensible reactive transport modeling capability complete with integrated data management, visualization, UQ, parameter estimation and other toolboxes (http://ascemdoe.org; Williamson et al, 2011). This effort builds on previous numerical modeling efforts at the SRS, including large scale flow and tracer transport modeling covering areas beyond the F-Area (Flach et al, 1998;Flach, 2004), as well as smaller-scale geochemical and reactive transport modeling aimed at understanding pH buffering and U(VI) transport in the F-Area saturated zone as a function of coupled physicochemical heterogeneity or 'reactive facies' (Sassen et al, 2012;Spycher et al, 2011).…”

Development of an advanced performance assessment modeling capability for geologic disposal of nuclear waste : methodology and requirements.

“…The Advanced Simulation Capabilities for Environmental Management (ASCEM) project is developing state-of-art computational and scientific tools and approaches for integrating data and scientific understanding to enable prediction of contaminant fate and transport in natural and engineered systems (Williamson et al 2011). The ASCEM project includes development of both multi-physics model and computational framework capabilities.…”

Advanced Simulation Capability for Environmental Management (ASCEM) Phase II Demonstration

“…To ensure Amanzi's design and capabilities support the wide range of conceptual models developed by Akuna, a high-level requirements document focused on the underlying complete mathematical formulations of the models was developed first (Steefel et al 2011). After prototyping key high-level concepts for the Phase I Demonstration , a high-level design document was developed for Amanzi .…”