Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks

S. Finsterle, B. Lanyon, M. Åkesson, S. Baxter, M. Bergström, N. Bockgård, W. Dershowitz, B. Dessirier, A. Frampton, Å. Fransson, A. Gens, B. Gylling, I. Hančilová, D. Holton, J. Jarsjö, J.-S. Kim, K.-P. Kröhn, D. Malmberg, Veli-Matti Pulkkanen, A. SawadaA. Sjöland, U. Svensson, P. Vidstrand, H. Viswanathan

    Research output: Contribution to journalArticleScientificpeer-review

    2 Citations (Scopus)

    Abstract

    Nuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components – which, in many cases, include a bentonite buffer surrounding waste packages – and the host rock. Contrasts in materials, together with gradients across the interface between the engineered and natural barriers, lead to complex interactions between these two subsystems. Numerical modelling, combined with monitoring and testing data, can be used to improve our overall understanding of rock–bentonite interactions and to predict the performance of this coupled system. Although established methods exist to examine the prediction uncertainties due to uncertainties in the input parameters, the impact of conceptual model decisions on the quantitative and qualitative modelling results is more difficult to assess. A Swedish Nuclear Fuel and Waste Management Company Task Force project facilitated such an assessment. In this project, 11 teams used different conceptualizations and modelling tools to analyse the Bentonite Rock Interaction Experiment (BRIE) conducted at the Äspö Hard Rock Laboratory in Sweden. The exercise showed that prior system understanding along with the features implemented in the available simulators affect the processes included in the conceptual model. For some of these features, sufficient characterization data are available to obtain defensible results and interpretations, whereas others are less supported. The exercise also helped to identify the conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems. The range of predicted bentonite wetting times encompassed by the ensemble results were considerably larger than the ranges derived from individual models. This is a consequence of conceptual uncertainties, demonstrating the relevance of using a multi-model approach involving alternative conceptualizations.
    Original languageEnglish
    Pages (from-to)261-283
    Number of pages23
    JournalGeological Society Special Publication
    Volume482
    Issue number1
    DOIs
    Publication statusPublished - 7 Dec 2018
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    Crystalline rocks
    natural barrier
    crystalline rock
    Radioactive wastes
    repository
    radioactive waste
    Bentonite
    bentonite
    Rocks
    modeling
    Nuclear fuels
    hard rock
    Waste management
    Waste disposal
    wetting
    waste disposal
    host rock
    waste management
    simulator
    Wetting

    Cite this

    Finsterle, S. ; Lanyon, B. ; Åkesson, M. ; Baxter, S. ; Bergström, M. ; Bockgård, N. ; Dershowitz, W. ; Dessirier, B. ; Frampton, A. ; Fransson, Å. ; Gens, A. ; Gylling, B. ; Hančilová, I. ; Holton, D. ; Jarsjö, J. ; Kim, J.-S. ; Kröhn, K.-P. ; Malmberg, D. ; Pulkkanen, Veli-Matti ; Sawada, A. ; Sjöland, A. ; Svensson, U. ; Vidstrand, P. ; Viswanathan, H. / Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks. In: Geological Society Special Publication. 2018 ; Vol. 482, No. 1. pp. 261-283.
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    title = "Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks",
    abstract = "Nuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components – which, in many cases, include a bentonite buffer surrounding waste packages – and the host rock. Contrasts in materials, together with gradients across the interface between the engineered and natural barriers, lead to complex interactions between these two subsystems. Numerical modelling, combined with monitoring and testing data, can be used to improve our overall understanding of rock–bentonite interactions and to predict the performance of this coupled system. Although established methods exist to examine the prediction uncertainties due to uncertainties in the input parameters, the impact of conceptual model decisions on the quantitative and qualitative modelling results is more difficult to assess. A Swedish Nuclear Fuel and Waste Management Company Task Force project facilitated such an assessment. In this project, 11 teams used different conceptualizations and modelling tools to analyse the Bentonite Rock Interaction Experiment (BRIE) conducted at the {\"A}sp{\"o} Hard Rock Laboratory in Sweden. The exercise showed that prior system understanding along with the features implemented in the available simulators affect the processes included in the conceptual model. For some of these features, sufficient characterization data are available to obtain defensible results and interpretations, whereas others are less supported. The exercise also helped to identify the conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems. The range of predicted bentonite wetting times encompassed by the ensemble results were considerably larger than the ranges derived from individual models. This is a consequence of conceptual uncertainties, demonstrating the relevance of using a multi-model approach involving alternative conceptualizations.",
    author = "S. Finsterle and B. Lanyon and M. {\AA}kesson and S. Baxter and M. Bergstr{\"o}m and N. Bockg{\aa}rd and W. Dershowitz and B. Dessirier and A. Frampton and {\AA}. Fransson and A. Gens and B. Gylling and I. Hančilov{\'a} and D. Holton and J. Jarsj{\"o} and J.-S. Kim and K.-P. Kr{\"o}hn and D. Malmberg and Veli-Matti Pulkkanen and A. Sawada and A. Sj{\"o}land and U. Svensson and P. Vidstrand and H. Viswanathan",
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    doi = "10.1144/SP482.12",
    language = "English",
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    Finsterle, S, Lanyon, B, Åkesson, M, Baxter, S, Bergström, M, Bockgård, N, Dershowitz, W, Dessirier, B, Frampton, A, Fransson, Å, Gens, A, Gylling, B, Hančilová, I, Holton, D, Jarsjö, J, Kim, J-S, Kröhn, K-P, Malmberg, D, Pulkkanen, V-M, Sawada, A, Sjöland, A, Svensson, U, Vidstrand, P & Viswanathan, H 2018, 'Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks', Geological Society Special Publication, vol. 482, no. 1, pp. 261-283. https://doi.org/10.1144/SP482.12

    Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks. / Finsterle, S.; Lanyon, B.; Åkesson, M.; Baxter, S.; Bergström, M.; Bockgård, N.; Dershowitz, W.; Dessirier, B.; Frampton, A.; Fransson, Å.; Gens, A.; Gylling, B.; Hančilová, I.; Holton, D.; Jarsjö, J.; Kim, J.-S.; Kröhn, K.-P.; Malmberg, D.; Pulkkanen, Veli-Matti; Sawada, A.; Sjöland, A.; Svensson, U.; Vidstrand, P.; Viswanathan, H.

    In: Geological Society Special Publication, Vol. 482, No. 1, 07.12.2018, p. 261-283.

    Research output: Contribution to journalArticleScientificpeer-review

    TY - JOUR

    T1 - Conceptual uncertainties in modelling the interaction between engineered and natural barriers of nuclear waste repositories in crystalline rocks

    AU - Finsterle, S.

    AU - Lanyon, B.

    AU - Åkesson, M.

    AU - Baxter, S.

    AU - Bergström, M.

    AU - Bockgård, N.

    AU - Dershowitz, W.

    AU - Dessirier, B.

    AU - Frampton, A.

    AU - Fransson, Å.

    AU - Gens, A.

    AU - Gylling, B.

    AU - Hančilová, I.

    AU - Holton, D.

    AU - Jarsjö, J.

    AU - Kim, J.-S.

    AU - Kröhn, K.-P.

    AU - Malmberg, D.

    AU - Pulkkanen, Veli-Matti

    AU - Sawada, A.

    AU - Sjöland, A.

    AU - Svensson, U.

    AU - Vidstrand, P.

    AU - Viswanathan, H.

    PY - 2018/12/7

    Y1 - 2018/12/7

    N2 - Nuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components – which, in many cases, include a bentonite buffer surrounding waste packages – and the host rock. Contrasts in materials, together with gradients across the interface between the engineered and natural barriers, lead to complex interactions between these two subsystems. Numerical modelling, combined with monitoring and testing data, can be used to improve our overall understanding of rock–bentonite interactions and to predict the performance of this coupled system. Although established methods exist to examine the prediction uncertainties due to uncertainties in the input parameters, the impact of conceptual model decisions on the quantitative and qualitative modelling results is more difficult to assess. A Swedish Nuclear Fuel and Waste Management Company Task Force project facilitated such an assessment. In this project, 11 teams used different conceptualizations and modelling tools to analyse the Bentonite Rock Interaction Experiment (BRIE) conducted at the Äspö Hard Rock Laboratory in Sweden. The exercise showed that prior system understanding along with the features implemented in the available simulators affect the processes included in the conceptual model. For some of these features, sufficient characterization data are available to obtain defensible results and interpretations, whereas others are less supported. The exercise also helped to identify the conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems. The range of predicted bentonite wetting times encompassed by the ensemble results were considerably larger than the ranges derived from individual models. This is a consequence of conceptual uncertainties, demonstrating the relevance of using a multi-model approach involving alternative conceptualizations.

    AB - Nuclear waste disposal in geological formations relies on a multi-barrier concept that includes engineered components – which, in many cases, include a bentonite buffer surrounding waste packages – and the host rock. Contrasts in materials, together with gradients across the interface between the engineered and natural barriers, lead to complex interactions between these two subsystems. Numerical modelling, combined with monitoring and testing data, can be used to improve our overall understanding of rock–bentonite interactions and to predict the performance of this coupled system. Although established methods exist to examine the prediction uncertainties due to uncertainties in the input parameters, the impact of conceptual model decisions on the quantitative and qualitative modelling results is more difficult to assess. A Swedish Nuclear Fuel and Waste Management Company Task Force project facilitated such an assessment. In this project, 11 teams used different conceptualizations and modelling tools to analyse the Bentonite Rock Interaction Experiment (BRIE) conducted at the Äspö Hard Rock Laboratory in Sweden. The exercise showed that prior system understanding along with the features implemented in the available simulators affect the processes included in the conceptual model. For some of these features, sufficient characterization data are available to obtain defensible results and interpretations, whereas others are less supported. The exercise also helped to identify the conceptual uncertainties that led to different assessments of the relative importance of the engineered and natural barrier subsystems. The range of predicted bentonite wetting times encompassed by the ensemble results were considerably larger than the ranges derived from individual models. This is a consequence of conceptual uncertainties, demonstrating the relevance of using a multi-model approach involving alternative conceptualizations.

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