2026-04-05T10:11:53Zhttps://recercat.cat/oai/request

oai:recercat.cat:2117/3424682026-01-21T09:47:16Zcom_2072_1033col_2072_452950

HM and THM interactions in bentonite engineered barriers for nuclear waste disposal Gens Solé, Antonio Alcoverro Bassols, Jordi Blaheta, Radim Hasal, Martin Michalec, Zdenek Takayama, Yusuke Lee, Changsoo Lee, Jaewon Kim, Geon Young Kuo, Wan-Jung Chia-Wei, Kuo Li, Chung-Yi Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia::Mecànica de sòls Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament dels residus Radioactive waste disposal in the ground Bentonite deposits DECOVALEX Engineered barriers Bentonite THM formulations Coupled numerical analyses Large-scale tests Bentonita Abocadors de residus radioactius Bentonite-based engineered barriers are a key component of many repository designs for the confinement of high-level radioactive waste and spent fuel. Given the complexity and interaction of the phenomena affecting the barrier, coupled hydro-mechanical (HM) and thermo-hydro-mechanical (THM) numerical analyses are a potentially useful tool for a better understanding of their behaviour. In this context, a Task (INBEB) was undertaken to study, using numerical analyses, the hydro-mechanical and thermo-hydro-mechanical Interactions in Bentonite Engineered Barriers within the international cooperative project DECOVALEX 2019. Two large scale tests, largely complementary, were selected for modelling: EB and FEBEX. The EB experiment was carried out under isothermal conditions and artificial hydration and it was dismantled after 10.7 years. The FEBEX test was a temperature-controlled non-isothermal test combined with natural hydration that underwent two dismantling operations, a partial one after 5 years of heating and a final one after a total of 18.4 years of heating. Direct observation of the state of the barriers was possible during the dismantling operations so that the evolution of barrier heterogeneity under transient conditions could be determined. Four teams performed the HM and THM numerical analyses using a variety of computer codes, formulations and constitutive laws. For each experiment, the basic features of the analyses are described and the comparison between calculations and field observations are presented and discussed. Comparisons involve measurements performed during the performance of the test and data gathered during dismantling. A final evaluation of the performance of the modelling closes the paper. DECOVALEX is an international research project comprising participants from industry, government and academia, focusing on development of understanding, models and codes in complex coupled problems in sub-surface geological and engineering applications; DECOVALEX-2019 is the current phase of the project. The authors appreciate and thank the DECOVALEX-2019 Funding Organisations: ANDRA, BGR/UFZ, CNSC, US DOE, ENSI, JAEA, IRSN, KAERI, NWMO, RWM, SÚRAO, SSM and Taipower for their financial and technical support of the work described in this report. The statements made in the report are, however, solely those of the authors and do not necessarily reflect those of the Funding Organisations. Martin Hasal (IGN) contribution was supported by the European Regional Development Fund under the project AI&Reasoning (reg. no. CZ.02.1.01/0.0/0.0/15 003/0000466). The JAEA contribution was partly funded by the Ministry of Economy, Trade and Industry of Japan (METI) through the program “The project for validating near-field system assessment methodology in geological disposal” (JFY2018). The KAERI contribution was supported by the Nuclear Research and Development Program of National Research Foundation of Korea (NRF) and funded by the Minister of Science, ICT, and Future Planning (NRF-2017M2A8A5014857). Peer Reviewed Postprint (author's final draft) 2021-01 Article https://www.sciencedirect.com/science/article/abs/pii/S1365160920309382 © 2019. Elsevier https://creativecommons.org/licenses/by-nc-nd/4.0/ Open Access Attribution-NonCommercial-NoDerivatives 4.0 International Elsevier