HM and THM interactions in bentonite engineered barriers for nuclear waste disposal

0537454 - ÚGN 2021 RIV GB eng J - Journal Article
Gens, A. - Alcoverro, J. - Blaheta, Radim - Hasal, Martin - Michalec, Zdeněk - Takayama, Y. - Lee, Ch. - Lee, J. - Kim, G. Y. - Kuo, Ch.-W. - Kuo, W.-J. - Lin, Ch.-Y.
HM and THM interactions in bentonite engineered barriers for nuclear waste disposal.
International Journal of Rock Mechanics and Mining Sciences. Roč. 137, January 2021 (2021), č. článku 104572. ISSN 1365-1609. E-ISSN 1873-4545
Institutional support: RVO:68145535
Keywords : DECOVALEX * engineered barriers * bentonite * THM formulations * coupled numerical analyses * large-scale test
OECD category: Environmental and geological engineering, geotechnics
Impact factor: 6.849, year: 2021
Method of publishing: Limited access
https://www.sciencedirect.com/science/article/pii/S1365160920309382?via%3Dihub

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 un-dertaken 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.
Permanent Link: http://hdl.handle.net/11104/0315239