Engineered Barrier System Research Activities at LBNL (FY2020 Progress Report)

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International Collaboration Activities in Geologic Disposal Research: FY2021 Progress

“…In addition to being the primary THMC modeling group supporting the HotBENT experiment, LBNL started in June 2019 a bench-scale laboratory experiment featuring a pressure column constructed to reproduce realistic heating and hydration conditions of the field-scale experiment (the so-called HotBENT Column test, or HotBENT Lab, see Section 8 in Zheng et al, 2020). To better separate the effects of heating and hydration, the experiment involved two identical test columns, with the control column undergoing only hydration, and the experiment column experiencing both heating up to 200ºC and hydration .…”

“…• Section 6.1.2.1 describes results of interpretative THMC modeling for the FEBEX experiment, including the development of a suitable THMC modeling framework and the results of detailed THMC simulations over the 18 years of heating (based on the reports by Zheng et al, 2020;.…”

“…In FY19, modeling efforts focused on the refinement of the chemical model to obtain a better understanding of chemical data based on the aqueous concentrations in bentonite. In FY20, Zheng et al (2020) applied the calibrated THMC model for the FEBEX test to predict the long-term evolution of engineered-natural barrier systems, in particular, to assess the effect of high temperature on mineralogical alterations of clay minerals, because illitization could potentially lead to decreasing the swelling capacity or reducing the adsorption potential of bentonite. In FY21, Zeng et al (2021, Section 9.2)) conducted simulations to predict a process of the long-term, up to 10,000 years, alteration of bentonite under conditions similar to the FEBEX in-situ test, and also developed a 1D reactive transport model to explain the data collected at the bentonite/concrete interface.…”

“…The application of the OpenMP parallelization of chemical routines on multi-core shared memory computers allowed for decreasing the computation time. In FY20, Zheng et al (2020) transitioned to a new simulator -TReactMech (Sonnenthal et al, 2015;2018) with new libraries, which modified the coupling strategy from iterative two-way coupling to a sequential coupling method.…”

“…From FY16 to FY19, the simulations for the FEBEX in-situ test evolved from a TH model (Zheng et al, 2016) to a THMC model that can reasonably interpret the coupled THMC data collected at the test site (Zheng et al, 2018b;2019a,b;. Because the TH model overestimated the relative humidity data and water content data (Zheng et al, 2016), additional processes were added seeking better match between data and model.…”