Conceptual and Numerical Modeling of Radionuclide Transport and Retention in Near-Surface Systems

This is an overview of the strategy used to describe the effects of a potential release from a radioactive waste repository on human exposure and future environments. It introduces a special issue of AMBIO, in which 13 articles show ways of understanding and characterizing the future. The study relies mainly on research performed in the context of a recent safety report concerning a repository for spent nuclear fuel in Sweden (the so-called SR-Site project). The development of a good understanding of on-site processes and acquisition of site-specific data facilitated the development of new approaches for assessment of surface ecosystems. A systematic and scientifically coherent methodology utilizes the understanding of the current spatial and temporal dynamics as an analog for future conditions. We conclude that future ecosystem can be inferred from a few variables and that this multidisciplinary approach is relevant in a much wider context than radioactive waste.

Section: Various Way To Handle the Uncertainty Of The Futuresupporting

confidence: 52%

Humans and Ecosystems Over the Coming Millennia: Overview of a Biosphere Assessment of Radioactive Waste Disposal in Sweden

Kautsky

Lindborg

Valentin³

2013

“…For a discussion of the reactiveness of the radionuclides in this safety-assessment study, see Erichsen et al (2013) and Piqué et al (2013). In Simpevarp, a larger proportion of a potential discharge would be transported out to open water than in Forsmark, and the site-specific differences in residence times and distribution of settled particles will increase over time as land uplift will make the Forsmark area more secluded from the Baltic Sea (Lindborg 2010; Lindborg et al 2013).…”

Section: Discussionmentioning

confidence: 99%

Difference in Particle Transport Between Two Coastal Areas in the Baltic Sea Investigated with High-Resolution Trajectory Modeling

Corell

Döös

2013

A particle-tracking model based on high-resolution ocean flow data was used to investigate particle residence times and spatial distribution of settling sediment for two geo-morphologically different Swedish coastal areas. The study was a part of a safety assessment for the location of a future nuclear-waste repository, and information about the particle-transport patterns can contribute to predictions of the fate of a possible leakage. It is also, to our knowledge, the first time particle-transport differences between two coastal areas have been quantified in this manner. In Forsmark, a funnel-shaped bay shielded by a number of islands, the average residence time for clay particles was 5 times longer than in the modeled part of Simpevarp, which is open to the Baltic Sea. In Forsmark, <10 % of the released particles left the domain compared to 60–80 % in Simpevarp. These site-specific differences will increase over time with the differences in land uplift between the areas.

“…For SKB’s safety assessment, the succession of landscape and future land uses during the forthcoming thousands of years are of major importance for the radionuclide modeling (Avila et al 2013; Piqué et al 2013). The regolith types studied here are most probably equivalent to the deposits that in the future might be cultivated and possibly affected by radionuclides (Avila et al 2013).…”

Section: Discussionmentioning

confidence: 99%

Inferences About Radionuclide Mobility in Soils Based on the Solid/Liquid Partition Coefficients and Soil Properties

Sohlenius

Saetre

Nordén

et al. 2013

To assist transport modeling in assessments of the radiological impact of a geological repository for radioactive wastes, the mobility of various elements was studied in arable and wetland soils in the Forsmark region, Sweden. Pore water and total element contents were determined for five types of unconsolidated deposits (regolith), spanning a wide range of soil properties with respect to pH and organic matter content. Two soil depths were sampled to capture element mobility in regolith layers affected and unaffected by soil-forming processes. The solid/liquid partition coefficients (Kd values) for most elements varied significantly among regolith types. For most elements, the observed variations in Kd values could be explained by variations in soil properties. For many elements, mobility increased with decreasing soil pH. The results provide a significant addition of data on radionuclide retention in soils, taking account of soil properties and processes.Electronic supplementary materialThe online version of this article (doi:10.1007/s13280-013-0408-4) contains supplementary material, which is available to authorized users.