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Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions

Received: 7 January 2022    Accepted: 4 February 2022    Published: 20 April 2022
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Abstract

Within the framework of the European research activities devoted to design the DEMO breeding blanket (BB), the Water-Cooled Lithium-Lead (WCLL) BB concept is one of the candidates currently assessed in EU. One of the main issues connected to its design is represented by the remote maintenance (RM) operations. In particular, previous thermo-mechanical analysis highlighted a Ductile to Brittle Transition Temperature (DBTT) shift above the room temperature within the WCLL central outboard (COB) segment during normal operation. This may pose problems during the RM operations foreseen in the BB replacement phase. Indeed, within those WCLL COB segment’s regions where the DBTT shifted above the room temperature, the stress level arising during RM operations may be able to promote crack growth and migration resulting in a fragile fracture event. Then, in this work, the structural assessment of the DEMO WCLL COB segment under RM scenarios is performed, in order to provide the fracture mechanics analysis with the necessary input in terms of stress spatial distribution and to understand if the deformation occurring during RM can be accommodated by the available space reservation. Several potential RM scenarios have been considered, taking into account also the potential occurrence of a seismic event or the necessity to remove the WCLL COB segment with the liquid breeder not drained. The study has been performed adopting a numerical approach based on the Finite Element Method and adopting the quoted Abaqus code. The obtained results are quite encouraging and will allow, in the follow up, the refinement of the RM plan foreseen for the WCLL BB.

Published in Nuclear Science (Volume 7, Issue 1)
DOI 10.11648/j.ns.20220701.11
Page(s) 1-6
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

WCLL BB, Thermo-mechanics, COB Segment, Remote Maintenance, Seismic

References
[1] T. Donné et al., European Research Roadmap to the Realisation of Fusion Energy, EUROfusion, 2018 (ISBN 978-3-00-061152-0).
[2] D. Chauvin et al., Design and feasibility of breeding blanket vertical segment-based architecture, Fus. Eng. Des., 173, 2021, 112941, https://doi.org/10.1016/j.fusengdes.2021.112941.
[3] F. Cismondi et al., Progress of the conceptual design of the European DEMO breeding blanket, tritium extraction and coolant purification systems, Fusion Engineering and Design, Volume 157, 2020, 111640, https://doi.org/10.1016/j.fusengdes.2020.111640.
[4] G. Federici et al., An overview of the EU breeding blanket design strategy as an integral part of the DEMO design effort, Fusion Engineering and Design, Volume 141, 2019, pages 30-42, https://doi.org/10.1016/j.fusengdes.2019.01.141.
[5] P. Arena et al., The DEMO Water-Cooled Lead-Lithium Breeding Blanket: design status at the end of the Pre-Conceptual Design Phase, 2021, Appl. Sci. 2021, 11, 11592, https://doi.org/10.3390/app112411592.
[6] C. Bachmann et al., Overview over DEMO design integration challenges and their impact on component design concepts, Fus Eng Design 2018, 136 Part A, 87-95.
[7] G. Federici et al., Overview of the design approach and prioritization of R&D activities towards an EU DEMO, Fus Eng Design 2016, 109-111, 1464-1474.
[8] S. Budden et al., Rescue and recovery studies for the DEMO blanket transporter, Fus. Eng. Design 2019, 146, Part B, 2494-2497.
[9] G. Keech et al., Issues of the vertical blanket segment architecture in DEMO: Current progress and resolution strategies, Fus. Eng. Design 2019, 146, Part B, 1408-1412.
[10] I. Farquhar, Parametric modelling of EU-DEMO remote maintenance strategies and concepts, Fus. Eng. Design 2019, 145, 29-32.
[11] P. A. Di Maio et al., Numerical assessment of the thermomechanical behaviour of the DEMO Water-Cooled Lithium Lead inboard blanket equatorial module, Fus. Eng. Design 2018, 136, 1178-1185.
[12] G. A. Spagnuolo et al., Development of load specifications for the design of the breeding blanket system, Fus. Eng. Design 2020, 157, 111657.
[13] C. Bachman, Conceptual study of the remote maintenance of the DEMO breeding blanket, EUROfusion internal report, April 2021, http://idm.euro-fusion.org/?uid=2PENV3.
[14] M. Mahler et al., Simplified approach for ductile fracture mechanics SSTT and its application to Eurofer97, Nuclear Materials and Energy 2021, 26, 100799.
[15] R. Mozzillo et al., Design of the European DEMO vacuum vessel inboard wall, Fus. Eng. Design 2020, 160, 111967.
Cite This Article
  • APA Style

    Gaetano Bongiovì, Pietro Alessandro Di Maio. (2022). Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions. Nuclear Science, 7(1), 1-6. https://doi.org/10.11648/j.ns.20220701.11

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    ACS Style

    Gaetano Bongiovì; Pietro Alessandro Di Maio. Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions. Nucl. Sci. 2022, 7(1), 1-6. doi: 10.11648/j.ns.20220701.11

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    AMA Style

    Gaetano Bongiovì, Pietro Alessandro Di Maio. Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions. Nucl Sci. 2022;7(1):1-6. doi: 10.11648/j.ns.20220701.11

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  • @article{10.11648/j.ns.20220701.11,
      author = {Gaetano Bongiovì and Pietro Alessandro Di Maio},
      title = {Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions},
      journal = {Nuclear Science},
      volume = {7},
      number = {1},
      pages = {1-6},
      doi = {10.11648/j.ns.20220701.11},
      url = {https://doi.org/10.11648/j.ns.20220701.11},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ns.20220701.11},
      abstract = {Within the framework of the European research activities devoted to design the DEMO breeding blanket (BB), the Water-Cooled Lithium-Lead (WCLL) BB concept is one of the candidates currently assessed in EU. One of the main issues connected to its design is represented by the remote maintenance (RM) operations. In particular, previous thermo-mechanical analysis highlighted a Ductile to Brittle Transition Temperature (DBTT) shift above the room temperature within the WCLL central outboard (COB) segment during normal operation. This may pose problems during the RM operations foreseen in the BB replacement phase. Indeed, within those WCLL COB segment’s regions where the DBTT shifted above the room temperature, the stress level arising during RM operations may be able to promote crack growth and migration resulting in a fragile fracture event. Then, in this work, the structural assessment of the DEMO WCLL COB segment under RM scenarios is performed, in order to provide the fracture mechanics analysis with the necessary input in terms of stress spatial distribution and to understand if the deformation occurring during RM can be accommodated by the available space reservation. Several potential RM scenarios have been considered, taking into account also the potential occurrence of a seismic event or the necessity to remove the WCLL COB segment with the liquid breeder not drained. The study has been performed adopting a numerical approach based on the Finite Element Method and adopting the quoted Abaqus code. The obtained results are quite encouraging and will allow, in the follow up, the refinement of the RM plan foreseen for the WCLL BB.},
     year = {2022}
    }
    

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  • TY  - JOUR
    T1  - Structural Assessment of the European DEMO Water-Cooled Lithium Lead Breeding Blanket Central Outboard Segment Under Remote Maintenance Loading Conditions
    AU  - Gaetano Bongiovì
    AU  - Pietro Alessandro Di Maio
    Y1  - 2022/04/20
    PY  - 2022
    N1  - https://doi.org/10.11648/j.ns.20220701.11
    DO  - 10.11648/j.ns.20220701.11
    T2  - Nuclear Science
    JF  - Nuclear Science
    JO  - Nuclear Science
    SP  - 1
    EP  - 6
    PB  - Science Publishing Group
    SN  - 2640-4346
    UR  - https://doi.org/10.11648/j.ns.20220701.11
    AB  - Within the framework of the European research activities devoted to design the DEMO breeding blanket (BB), the Water-Cooled Lithium-Lead (WCLL) BB concept is one of the candidates currently assessed in EU. One of the main issues connected to its design is represented by the remote maintenance (RM) operations. In particular, previous thermo-mechanical analysis highlighted a Ductile to Brittle Transition Temperature (DBTT) shift above the room temperature within the WCLL central outboard (COB) segment during normal operation. This may pose problems during the RM operations foreseen in the BB replacement phase. Indeed, within those WCLL COB segment’s regions where the DBTT shifted above the room temperature, the stress level arising during RM operations may be able to promote crack growth and migration resulting in a fragile fracture event. Then, in this work, the structural assessment of the DEMO WCLL COB segment under RM scenarios is performed, in order to provide the fracture mechanics analysis with the necessary input in terms of stress spatial distribution and to understand if the deformation occurring during RM can be accommodated by the available space reservation. Several potential RM scenarios have been considered, taking into account also the potential occurrence of a seismic event or the necessity to remove the WCLL COB segment with the liquid breeder not drained. The study has been performed adopting a numerical approach based on the Finite Element Method and adopting the quoted Abaqus code. The obtained results are quite encouraging and will allow, in the follow up, the refinement of the RM plan foreseen for the WCLL BB.
    VL  - 7
    IS  - 1
    ER  - 

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Author Information
  • Department of Engineering, University of Palermo, Palermo, Italy

  • Department of Engineering, University of Palermo, Palermo, Italy

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