Guidance on numerical modelling of thermo-hydro-mechanical coupled processes for performance assessment of radioactive waste repositories

• This paper provides advice on how to incorporate thermo-hydro-mechanical (THM) coupled processes into performance and safety assessments and design studies for radioactive waste disposal in geological formations. The advice is based on work conducted for the EU research project BENCHPAR: "Benchmark Tests and Guidance on Coupled Processes for Performance Assessment of Nuclear Waste Repositories". In Section 1, there is an explanation of why numerical analyses incorporating THM mechanisms are required for radioactive waste studies and background material on the subject is provided. Then, the THM processes and their interactions are explained in Section 2. Three case examples of THM numerical analysis are presented in Section 3 to illustrate the type of work that can be conducted to study the near-field, upscaling, and the far-field. The importance and priority of the THM couplings are summarized in Section 4. Recommended soft and hard auditing procedures are presented in Section 5. We place special emphasis on the fact that the most important step in numerical modelling is not executing the calculations per se, but the earlier conceptualization of the problem regarding the dominant processes, the material properties and parameters, the engineering perturbations, and their mathematical presentations. The associated modelling component of addressing the uncertainties and estimating their influence on the results is also important. Thus, the specific models and codes should be studied first to evaluate the harmony between the nature of the problem and the nature of the codes. The tactical use of particular numerical techniques will then be based on a sound strategic foundation. An associated listing of bullet point recommendations and issues for future directions for this THM subject area is given in Section 6.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Naturresursteknik -- Mineral- och gruvteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Environmental Engineering -- Mineral and Mine Engineering (hsv//eng)

Nyckelord

radioactive

modeling

coupled

numerical

guidance

Geoengineering and mining engineering

Geoteknik och gruvteknik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)