Modelling of the LTDE-SD radionuclide diffusion experiment in crystalline rock at the sp Hard Rock Laboratory (Sweden)

Soler, J. M.*; Meng, S.*; Moreno, L.*; Neretnieks, I.*; Liu, L.*; Keklinen, P.*; Hokr, M.*; ha, J.*; Vetenk, A.*; Reimitz, D.*; Vik, J.*; Voplka, D.*; Krhn, K.-P.*; Tachi, Yukio  ; Ito, Tsuyoshi*; Svensson, U.*; Iraola, A.*; Trinchero, P.*; Voutilainen, M.*; Deissmann, G.*; Bosbach, D.*; Park, D. K.*; Ji, S.-H.*; Gvodk, L.*; Milick, M.*; Polk, M.*; Gylling, B.*; Lanyon, G. W.*

Task 9B of the SKB Task Force on Modelling of Groundwater Flow and Transport of Solutes in fractured rock focused on the modelling of experimental results from the LTDE-SD in situ tracer test performed at the sp Hard Rock Laboratory in Sweden. Ten different modelling teams provided results for this exercise, using different concepts and codes. Three main types of modelling approaches were used: (1) analytical solutions to the transport-retention equations, (2) continuum-porous-medium numerical models, and (3) microstructure-based models accounting for small-scale heterogeneity (i.e. mineral grains and microfracture distributions). The modelling by the different teams allowed the comparison of many different model concepts, especially in terms of potential zonations of rock properties (porosity, diffusion, sorption), such as the presence of a disturbed zone at the rock and fracture surface, the potential effects of micro- and cm-scale fractures.