Significance of fracture rim zone heterogeneity for tracer transport in crystalline rock
2010 (English)In: Water resources research, ISSN 0043-1397, E-ISSN 1944-7973, Vol. 46, no 3, W03504- p.Article in journal (Refereed) Published
Conducting fractures of crystalline rock are typically altered over long periods of time. The fracture rim zone, a result of these alterations, will as a rule have different physical and chemical properties from the unaltered ("fresh'') rock, depending on various microscopic and macroscopic factors of the alterations. In this paper, we study the impact of rim zone heterogeneity, exemplified by a decreasing porosity trend as inferred from the Aspo Hard Rock Laboratory site (Sweden), on short- and long-term tracer transport. Our main finding is that this particular rim zone structure will have a dominant effect on transport of moderately to strongly sorbing tracers on experimental time scales and a notable effect on application time scales. The findings of this work lend further support to the interpretation of the relatively strong retention reported by Cvetkovic et al. The fracture rim zone porosity structure may provide an additional safety margin for sorbing radionuclides in crystalline rock at sites where fracture alteration is prevalent.
Place, publisher, year, edition, pages
2010. Vol. 46, no 3, W03504- p.
matrix diffusion, porosity, flow
Water Engineering Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:kth:diva-19291DOI: 10.1029/2009wr007755ISI: 000275321900002ScopusID: 2-s2.0-77949628811OAI: oai:DiVA.org:kth-19291DiVA: diva2:337338
QC 201005252010-08-052010-08-052011-01-24Bibliographically approved