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Evaluation of Engineered Barrier Systems (FY19 Report)

Matteo, Edward N.; Hadgu, Teklu H.; Zheng, L.Z.; Xu, H.X.; Wainwright, H.W.; Subramanian, N.S.; Voltolini, M.V.; Lammers, L.L.; Gilbert, B.G.; MacDowell, A.M.; Nichol, J.N.; Lisabeth, H.L.; van Hartesveldt, N.F.; Migdissov, A.M.; Strzelecki, A.C.S.; Xu, H.X.; CAproruscio, F.C.; Roback, R.R.; White, J.W.; Buck, E.C.; Yu, X-Y Y.; Yao, J.Y.; Reilly, D.D.; Son, J.S.; Chatterjee, S.D.; McNamara, B.K.; Ilton, E.S.; Claret, F.C.; Gaboreau, S.G.; Ermakova, D.E.; Gabitov, R.G.

This report describes research and development (R&D) activities conducted during fiscal year 2019 (FY19) specifically related to the Engineered Barrier System (EBS) R&D Work Package in the Spent Fuel and Waste Science and Technology (SFWST) Campaign supported by the United States (U.S.) Department of Eneregy (DOE). The R&D activities focus on understanding EBS component evolution and interactions within the EBS, as well as interactions between the host media and the EBS. A primary goal is to advance the development of process models that can be implemented directly within the Genreric Disposal System Analysis (GDSA) platform or that can contribute to the safety case in some manner such as building confidence, providing further insight into the processes being modeled, establishing better constraints on barrier performance, etc.The FY19 EBS activities involved not only modeling and analysis work, but experimental work as well. The report documents the FY19 progress made in seven different research areas as follows: (1) thermal analysis for the disposal of dual purpose canisters (DPCs) in sedimentary host rock using the semianalytical method, (2) tetravalent uranium solubility and speciation, (3) modeling of high temperature, thermal-hydrologic-mechanical-chemical (THMC) coupled processes, (4) integration of coupled thermalhydrologic- chemical (THC) model with GDSA using a Reduced-Order Model, (5) studying chemical controls on montmorillonite structure and swelling pressure, (6) transmission x-ray microscope for in-situ nanotomography of bentonite and shale, and (7) in-situ electrochemical testing of uranium dioxide under anoxic conditions. The R&D team consisted of subject matter experts from Sandia National Laboratories, Lawrence Berkeley National Laboratory (LBNL), Los Alamos National Laboratory (LANL), Pacific Northwest National Laboratory (PNNL), the Bureau de Recherches Géologiques et Minières (BRGM), the University of California Berkeley, and Mississippi State University. In addition, the EBS R&D work leverages international collaborations to ensure that the DOE program is active and abreast of the latest advances in nuclear waste disposal. For example, the FY19 work on modeling coupled THMC processes at high temperatures relied on the bentonite properties from the Full-scale Engineered Barrier EXperiment (FEBEX) Field Test conducted at the Grimsel Test Site in Switzerland. Overall, significant progress has been made in FY19 towards developing the modeling tools and experimental capabilities needed to investigate the performance of EBS materials and the associated interactions in the drift and the surrounding near-field environment under a variety of conditions including high temperature regimes.

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TYPE Other Report YEAR 2020
OSTIDOI

Initial Simulations of Empty Room Collapse and Reconsolidation at the Waste Isolation Pilot Plant

Reedlunn, Benjamin R.; Moutsanidis, Georgios M.; Baek, Jonghyuk B.; Huang, Tsung-Hui H.; Koester, Jacob K.; Matteo, Edward N.; He, Xiaolong H.; Taneja, Karan T.; Wei, Haoyan W.; Bazilevs, Yuri B.; Chen, Jiun-Shyan C.; Mitchell, Chven A.; Lander, Robert L.; Dewers, Thomas D.

The Waste Isolation Pilot Plant (WIPP) is a geologic repository for defense-related nuclear waste. If left undisturbed, the virtually impermeable rock salt surrounding the repository will isolate the nuclear waste from the biosphere. If humans accidentally intrude into the repository in the future, then the likelihood of a radionuclide release to the biosphere will depend significantly on the porosity and permeability of the repository itself. Room ceilings and walls at the WIPP tend to collapse over time, causing rubble piles to form on floors of empty rooms. The surrounding rock formation will gradually compact these rubble piles until they eventually become solid salt, but the length of time for a rubble pile to reach a certain porosity and permeability is unknown. This report details the first efforts to build models to predict the porosity and permeability evolution of an empty room as it closes. Conventional geomechanical numerical methods would struggle to model empty room collapse and rubble pile consolidation, so three different meshless methods, the Immersed Isogeometric Analysis Meshfree, Reproducing Kernel Particle Method (RKPM), and the Conformal Reproducing Kernel method, were assessed. First, the meshless methods and the finite element method each simulated gradual room closure, without ceiling or wall collapse. All three methods produced equivalent room closure predictions with comparable computational speed. Second, the Immersed Isogeometric Analysis Meshfree method and RKPM simulated two-dimensional empty room collapse and rubble pile consolidation. Both methods successfully simulated large viscoplastic deformations, fracture, and rubble pile rearrangement to produce qualitatively realistic results. In addition to geomechanical simulations, the flow channels in damaged salt and crushed salt were measured using micro-computed tomography, and input into a computational fluid dynamics simulation to predict the salt's permeability. Although room for improvement exists, the current simulation approaches appear promising.

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TYPE SAND Report YEAR 2019
OSTIDOI

Monitoring and Repair of Cement-Geomaterial Interfaces in Borehole and Repository Scenarios

Matteo, Edward N.; McMahon, Kevin A.; Camphouse, Russell C.; Dewers, Thomas D.; Jove Colon, Carlos F.; Fuller, Timothy J.; Mohahgheghi, J.M.; Stormont, J.C.; Taha, M.T.; Pyrak-Nolte, L.P.; Wang, C.-F.; Douba, A.D.; Genedy, M.G.; Fernandez, S.G.; Kandil, U.F.; Soliman, E.E.; Starr, J.S.; Stenko, M.S.

The failure of subsurface seals (i.e., wellbores, shaft and drift seals in a deep geologic nuclear waste repository) has important implications for US Energy Security. The performance of these cementitious seals is controlled by a combination of chemical and mechanical forces, which are coupled processes that occur over multiple length scales. The goal of this work is to improve fundamental understanding of cement-geomaterial interfaces and develop tools and methodologies to characterize and predict performance of subsurface seals. This project utilized a combined experimental and modeling approach to better understand failure at cement-geomaterial interfaces. Cutting-edge experimental methods and characterization methods were used to understand evolution of the material properties during chemo-mechanical alteration of cement-geomaterial interfaces. Software tools were developed to model chemo-mechanical coupling and predict the complex interplay between reactive transport and solid mechanics. Novel, fit-for-purpose materials were developed and tested using fundamental understanding of failure processes at cement- geomaterial interfaces. ACKNOWLEDGEMENTS The authors wish to acknowledge the Earth Sciences Research Foundation for their generous support over the last three years. In particular, we thank Erik Webb for his numerous suggestions, comments, feedback, and encouragement over the course of the project. There many who helped bring this project to fruition, including: Dave Borns, Steve Bauer, Pania Newell, Heeho Park, and Doug Blankenship. There are many support personnel who we thank for their valuable contributions to the logistics and business of management side of the project, including: Tracy Woolever, Libby Sanzero, and Nancy Vermillion.

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TYPE SAND Report YEAR 2019
OSTIDOI

Nanomodified Methyl Methacrylate Polymer for Sealing of Microscale Defects in Wellbore Systems

Journal of Materials in Civil Engineering

Genedy, Moneeb; Matteo, Edward N.; Stenko, Michael; Stormont, John C.; Taha, Mahmoud R.

Microscale defects (microannuli) at the steel-cement and rock-cement interfaces are a major cause of failure in the integrity of wellbore systems. Microscale defects/microcracks as small as 30 μm are sufficient to create a significant leakage pathway for fluids. In this paper, the authors propose the use of nanomodified methyl methacrylate (NM-MMA) polymer as a seal material for 30-μm microcracks. Four materials were evaluated for their ability to serve as an effective seal material to seal 30-μm microcracks: microfine cement, epoxy, methyl methacrylate (MMA), and NM-MMA incorporating 0.5% by weight aluminum nanoparticles (ANPs). The seal materials' bond strengths with shale were investigated using push-out tests. In addition, the ability to flow fluid through the microcracks was investigated using sagittal microscopic images. Viscosity, surface tension, and contact angle measurements explain the superior ability of MMA seal materials to flow into very thin microcracks compared with other materials. Post-test analysis shows MMA repair materials are capable of completely filling the microcracks. In addition, incorporating ANPs in MMA resulted in significant improvement in seal material ductility. Dynamic mechanical analysis (DMA) showed that incorporating ANPs in MMA reduced the creep compliance and improved creep recovery of NM-MMA. X-ray diffraction (XRD) analysis shows that incorporating ANPs in MMA resin increases the degree of polymer crystallization, resulting in significant improvement in seal material ductility.

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TYPE Journal Article YEAR 2019
ScopusOSTIDOI
Results 51–75 of 184
Results 51–75 of 184