Analysis of fluid flow and solute transport through a single fracture with variable apertures intersecting a canister: Comparison between fractal and Gaussian fractures
2006 (English)In: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 31, no 14-okt, 634-639 p.Article in journal (Refereed) Published
Canisters with spent nuclear fuel will be deposited in fractured crystalline rock in the Swedish concept for a final repository. The fractures intersect the canister holes at different angles and they have variable apertures and therefore locally varying flowrates. Our previous model with fractures with a constant aperture and a 90 degrees intersection angle is now extended to arbitrary intersection angles and stochastically variable apertures. It is shown that the previous basic model can be simply amended to account for these effects. More importantly, it has been found that the distributions of the volumetric and the equivalent flow rates are all close to the Normal for both fractal and Gaussian fractures, with the mean of the distribution of the volumetric flow rate being determined solely by the hydraulic aperture, and that of the equivalent flow rate being determined by the mechanical aperture. Moreover, the standard deviation of the volumetric flow rates of the many realizations increases with increasing roughness and spatial correlation length of the aperture field, and so does that of the equivalent flow rates. Thus, two simple statistical relations can be developed to describe the stochastic properties of fluid flow and solute transport through a single fracture with spatially variable apertures. This obviates, then, the need to simulate each fracture that intersects a canister in great detail, and allows the use of complex fractures also in very large fracture network models used in performance assessment.
Place, publisher, year, edition, pages
2006. Vol. 31, no 14-okt, 634-639 p.
groundwater, fluid flow, solute transport, fractures, modelling
IdentifiersURN: urn:nbn:se:kth:diva-15978DOI: 10.1016/j.pce.2006.04.012ISI: 000240386200018ScopusID: 2-s2.0-33746329585OAI: oai:DiVA.org:kth-15978DiVA: diva2:334020
QC 20100525 QC 20111005. Conference: 10th International Conference on Chemistry and Migration of Actinides and Fission Products. Avignon, FRANCE. SEP 18-23, 2005 2010-08-052010-08-052011-10-05Bibliographically approved