Development and Improvement Of Numerical methods and Tools for modelling coupled processes (DONUT)

Improved understanding of the upscaling THMC modelling for coupled hydro-mechanical-chemical processes in time and space.

Major highlights (June 2022 - May 2023)

•    A webinar has been held on april 14th 2023 to discuss about the deliverables. It includes their content, and how to deliver them in due time.
•    Two joint sessions were organized with MODATS and UMAN during the last EURAD annual meeting that was held in Cyprus

Forward look

•    On June 29th and 30th 2023 the final DONUT meeting will be held in Paris (France)
•    On November 8th, 9th and 10th a joint ACED DONUT workshop entitled “Assessing the long term-evolution of engineered barrier systems of waste disposal sytems” will be held in Mechelen (Belgium)
•    DONUT main achievement will be presented at the Migration conference held in Nantes


This WP will develop and improve specific numerical methods and tools that allow efficient modelling coupled processes, considering (i) the versatility of numerical methods with regards to the various tools used by “end-users”; and (ii) a demonstration of robustness and added-value of developments by benchmark of the methods and tools on representative test cases at large repository time and space scales.


The DONUT WP has been selected for the first phase of EURAD as it will address the following activities identified as a high or medium level of common interest in Theme 7 “Performance assessment, safety case development and safety analyses” of the Roadmap: 

  • Improved understanding of the upscaling of THMC modelling for coupled hydromechanical-chemical processes in time and space (Phase 1 of the Roadmap). 
  • Improved understanding and models for the impact of THMC on the behaviour of the host rock and the buffer materials (Phase 2 of the Roadmap).
  • Improved multi-scale reactive transport models (Phase 2 of the Roadmap)
  • Improved performance assessment tools (Phases 0 and 1 of the Roadmap).
  • Further refinement of methods to make sensitivity and uncertainty analyses (Phases 2 and 3 of the Roadmap)
  • Improved computing (Phases 3 and 4 of the Roadmap).

Furthermore, by improving the numerical methods and tools that are able to manage multi-physicals coupled processes, the work conducted in this WP is relevant for better description of site evolution and design optimization. Both can be applied to deep geological and near surface radioactive waste disposal. Finally, by providing efficient numerical means for analysis, DONUT will, contribute to abstraction for safety case (quantification of safety margins, detailed assessment of safety functions allocated to components…).