Publications

Hadgu, Teklu H.; Dewers, Thomas D.; Matteo, Edward N.

Abstract not provided.

Simo, E.S.; Herold, P.H.; Keller, A K.; Lommerzheim, A.L.; Matteo, Edward N.; Hadgu, Teklu H.; Jayne, Richard S.; Mills, Melissa M.; Kuhlman, Kristopher L.

Abstract not provided.

Simo, E.S.; Herold, P.H.; Keller, A K.; Lommerzheim, A.L.; Matteo, Edward N.; Hadgu, Teklu H.; Jayne, Richard S.; Mills, Melissa M.; Kuhlman, Kristopher L.

Abstract not provided.

Simo, E.S.; Herold, P.H.; Keller, A K.; Lommerzheim, A.L.; Matteo, Edward N.; Hadgu, Teklu H.; Jayne, Richard S.; Mills, Melissa M.; Kuhlman, Kristopher L.

Abstract not provided.

Keller, Andreas K.; Simo, Eric K.; Herold, Phillipe H.; Lommerzheim, Andreas L.; Matteo, Edward N.; Hadgu, Teklu H.; Jayne, Richard S.; Mills, Melissa M.; Kuhlman, Krisotpher K.

Abstract not provided.

Mitchell, Chven A.; Matteo, Edward N.; Pyrak-Nolte, Laura J.

Abstract not provided.

Stein, Emily S.; Bryan, Charles R.; Dobson, David C.; Hardin, Ernest H.; Jove Colon, Carlos F.; Lopez, Carlos M.; Matteo, Edward N.; Mohanty, Sitakanta N.; Pendleton, Martha W.; Perry, Frank V.; Prouty, Jeralyn L.; Sassani, David C.; Wang, Yifeng; Rutqvist, Jonny R.; Zheng, Liange Z.; Sauer, Kirsten B.; Caporuscio, Florie C.; Howard, Robert H.; Adeniyi, Abiodun A.; Joseph, Robby J.

Disposal of large, heat-generating waste packages containing the equivalent of 21 pressurized water reactor (PWR) assemblies or more is among the disposal concepts under investigation for a future repository for spent nuclear fuel (SNF) in the United States. Without a long (>200 years) surface storage period, disposal of 21-PWR or larger waste packages (especially if they contain high-burnup fuel) would result in in-drift and near-field temperatures considerably higher than considered in previous generic reference cases that assume either 4-PWR or 12-PWR waste packages (Jové Colón et al. 2014; Mariner et al. 2015; 2017). Sevougian et al. (2019c) identified high-temperature process understanding as a key research and development (R&D) area for the Spent Fuel and Waste Science and Technology (SFWST) Campaign. A two-day workshop in February 2020 brought together campaign scientists with expertise in geology, geochemistry, geomechanics, engineered barriers, waste forms, and corrosion processes to begin integrated development of a high-temperature reference case for disposal of SNF in a mined repository in a shale host rock. Building on the progress made in the workshop, the study team further explored the concepts and processes needed to form the basis for a high-temperature shale repository reference case. The results are described in this report and summarized..

Matteo, Edward N.

Abstract not provided.

Hadgu, Teklu H.; Matteo, Edward N.; Grimmer, Peter W.; Dewers, Thomas D.

Abstract not provided.

Kuhlman, Kristopher L.; Mills, Melissa M.; Jayne, Richard S.; Herrick, Courtney G.; Choens, Robert C.; Nemer, Martin N.; Heath, Jason; Matteo, Edward N.; Xiong, Yongliang X.; Otto, Shawn O.; Dozier, Brian D.; Weaver, Doug W.; Stauffer, Phil S.; Guiltinan, Eric J.; Boukhalfa, Hakim B.; Rahn, Thom R.; Wu, Yuxin W.; Rutqvist, Jonny R.; Hu, Mengsu H.; Crandall, Dustin C.

Abstract not provided.

Matteo, Edward N.; Hadgu, Teklu H.; Dewers, Thomas D.

Abstract not provided.

Mills, Melissa M.; Kuhlman, Kristopher L.; Matteo, Edward N.

Abstract not provided.

Hadgu, Teklu H.; Dewers, Thomas D.; Matteo, Edward N.; Gomez, Steven P.

Abstract not provided.

Matteo, Edward N.

Abstract not provided.

Bar-nes, G.B.; Klein-BenDavid, O.K.; Kosson, D K.; Gruber, C.G.; Taylor, A.J.; Brown, K.G.; Delapp, R.D.; Brown, L.B.; Ayers, J.A.; Meeussen, H.M.; Matteo, Edward N.; Jove Colon, Carlos F.; Mitchell, Chven A.; Pyrak-Nolte, L.P.

Abstract not provided.

Bar-nes, G.B.; Klein-BenDavid, O.K.; Kosson, D K.; Gruber, C.G.; Taylor, A.J.; Brown, K.G.; Delapp, R.D.; Brown, L.B.; Ayers, J.A.; Meeussen, H.M.; Matteo, Edward N.; Jove Colon, Carlos F.; Mitchell, Chven A.; Pyrak-Nolte, L.P.

Abstract not provided.

Matteo, Edward N.

Abstract not provided.

Matteo, Edward N.; Dewers, Thomas D.; Gomez, Steven P.; Hadgu, Teklu H.; Zheng, L.Z.; Lammers, L.L.; Fox, P.F.; Chang, C.C.; Xu, H.X.; Borglin, S.B.; Whittaker, M.W.; Chou, C.C.; Tournassat, N.T.; Subramanian, S.S.; Wu, Y.W.; Nico, P.N.; Gilbert, B.G.; Kneafsey, T.K.; Caporuscio, F.A.; Sauer, K.B.; Rock, M.J.; Kalintsev, A.K.; Migdissov, A.M.; Alcorn, C.A.; Buck, E.C.; Yu, X-Y Y.; Yao, J.Y.; Son, J.S.; Reichers, S.L.; Klein-BenDavid, O.K.; Bar-nes, G.B.; Meeusen, J.C.; Gruber, C.G.; Steen, M S.; Brown, K.G.; Delapp, R.D.; Taylor, A.J.; Ayers, J.A.; Kosson, D.S.

This report describes research and development (R&D) activities conducted during fiscal year 2020 (FY20) 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 Energy (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 Generic 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 FY20 EBS activities involved not only modeling and analysis work, but experimental work as well. Despite delays to some planned activities due to COVID-19 precautions, progress was made during FY20 in multiple research areas and documented in this report as follows: (1) EBS Task Force: Task 9/FEBEX Modeling Final Report: Thermo-Hydrological Modeling with PFLOTRAN, (2) preliminary sensitivity analysis for the FEBEX in-situ heater test, (3) cement-carbonate rock interaction under saturated conditions: from laboratory to modeling, (4) hydrothermal experiments, (5) progress on investigating the high temperature behavior of the uranyl-carbonate complexes, (6) in-situ and electrochemical work for model validation, (7) investigation of the impact of high temperature on EBS bentonite with THMC modeling, (8) sorption and diffusion experiments on bentonite, (9) chemical controls on montmorillonite structure and swelling pressure, (10) microscopic origins of coupled transport processes in bentonite, (11) understanding the THMC evolution of bentonite in FEBEX-DP—coupled THMC modeling, (12) modeling in support of HotBENT, an experiment studying the effects of high temperatures on clay buffers/near-field, and (13) high temperature heating and hydration column test on bentonite.

Hadgu, Teklu H.; Clayton, Daniel J.; Hardin, Ernest H.; Matteo, Edward N.

Abstract not provided.

Matteo, Edward N.; Kuhlman, Kristopher L.; Hadgu, Teklu H.; Herrera-Mills, Marissa H.; Jayne, Richard S.; Simo, Eric K.; Lommerzheim, Andree L.; Hrold, Phillip H.; Kellers, Adreas K.

Abstract not provided.

Lommerzheim, Andree L.; Matteo, Edward N.

Abstract not provided.

Kuhlman, Kristopher L.; Matteo, Edward N.; Mills, Melissa M.; Jayne, Richard S.; Reedlunn, Benjamin R.; Sobolik, Steven R.; Bean, James B.; Stein, Emily S.; Gross, Michael B.

This report is a summary of the international collaboration work conducted by Sandia and funded by the US Department of Energy Office (DOE) of Nuclear Energy Spent Fuel and Waste Science & Technology (SFWST) as part of the Sandia National Laboratories Salt R&D and Salt International work packages. This report satisfies milestone level-three milestone M3SF-205N010303062. Several stand-alone sections make up this summary report, each completed by the participants. The first two sections discuss international collaborations on geomechanical benchmarking exercises (WEIMOS), granular salt reconsolidation (KOMPASS), engineered barriers (RANGERS), and documentation of Features, Events, and Processes (FEPs).

Hadgu, Teklu H.; Dewers, Thomas D.; Gomez, Steven P.; Matteo, Edward N.

This report outlines Sandia National Laboratories modeling studies applied to Stage 1 and Stage 2 of the Full-scale Engineered Barriers Experiment in Crystalline Host Rock (FEBEX) in situ test for the SKB EBS Task Force Task 9. The FEBEX test was a full-scale test conducted over ~18 years at the Grimsel, Switzerland Underground Research Laboratory (URL) managed by NAGRA. It involved emplacing simulated waste packages, in the form of welded cylindrical heaters, inside a tunnel in crystalline granitic rock and surrounded by a bentonite barrier and cement plug. Sensors emplaced within the bentonite monitored the wetting-up, heating, and drying out of the bentonite barrier, and the large resulting data set provides an excellent opportunity for validation of multiphysics Thermal-Hydrological (TH), Thermal-Hydrologic-Chemical (THC), and Thermal-Hydrological-Mechanical (THM) modeling approaches for underground nuclear waste storage and the performance of engineered bentonite barriers. The present status of the EBS Task Force is finalizing Task 9, which follows years of modeling studies of the FEBEX test, by many notable modeling teams (Gens et al., 2009; Sanchez et al. 2010; 2012; Samper et al., 2018). These modeling studies generally use two-dimensional axisymmetric meshes, ignoring threedimensional effects, gravity and asymmetric wetting and dry out of the bentonite engineered barrier. This study investigates these effects with use of the PFLOTRAN THC code with massively parallel computational methods in modeling FEBEX Stage 1 and Stage 2 results. The PFLOTRAN numerical code is an open source, state-of-the-art, massively parallel subsurface flow and reactive transport code operating in a high-performance computing environment (Hammond et al., 2014). Section 2 describes the applied partial differential equations describing mass, momentum and energy balance used in this study, considerations derived by assuming phase equilibrium between gas and liquid phases, constitutive equations for granite, cement plug, and bentonite domains, and specific approaches for use inthe PFLOTRAN code. Section 3 describes the geometry, meshing, and model set-up. Section 4 describes modeling results, Section 5 compares modeling results to field testing data, and Section 6 gives conclusions. The Appendix provides detailed information required by the EBSTask Force for final reporting.

Matteo, Edward N.; Mitchell, Chven A.; Dewers, Thomas D.

Abstract not provided.

Matteo, Edward N.; Dewers, Thomas D.; Fuller, Timothy J.; Mills, Melissa M.; Jove Colon, Carlos F.

Abstract not provided.