Impact of temperature increase on nuclide transport in crystalline rock on the near field scale
2004 (English)In: Coupled Thermo-Hydro-Mechanical-Chemical Processes in Geo-Systems: Fundamentals, Modelling, Experiments and Applications, Elsevier , 2004, 2, 413-418 p.Chapter in book (Other academic)
The TRUE (“Tracer Retention Understanding Experiments”) programme at the Äspö Hard Rock Laboratory (Winberg et al., 2000, 2002) has since 1995 generated a unique database for quantifying retention of radionuclides in crystalline rock on the 5-30m scales. Temperature conditions in the TRUE analysis were about 15°C. In this study, we consider the effect of temperature increase to ca 60°C consistent with conditions after say 1000 years in the rock volume surrounding a KBS-3 type of repository, anticipated to persist over a relatively long time. Temperature elevation will decrease the mean aperture of a conducting fracture by approximately 30%, which in turn will enhance retention. Furthermore, diffusion in the rock matrix will increase at elevated temperatures by approximately factor 4, further enhancing retention. Sorption coefficients are assumed to be unchanged since there is still considerable uncertainty regarding sorption and its change with increasing temperature. We show that elevated temperature on the near field scale enhances nuclide retention, thereby providing an additional safety margin.
Place, publisher, year, edition, pages
Elsevier , 2004, 2. 413-418 p.
, Elsevier Geo-Engineering Book Series
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-8792DOI: 10.1016/S1571-9960(04)80076-4ScopusID: 2-s2.0-77957030590OAI: oai:DiVA.org:kth-8792DiVA: diva2:14221
QC 201006242005-11-222005-11-222010-06-24Bibliographically approved